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Home My WebLink About891508.tiff CORNWELL & BLAKEY ATTORNEYS AND COUNSELORS AT LAW SUITE 2650SEVENTEENTH STREET PLAZA _ 1225 SEVENTEENTH STREET DENVER,COLORADO 80202 (303)295-2500 TELEX: (303)298-8213 August 28, 1989 VIA FEDERAL EXPRESS Clerk of the Board of County Commissioners Weld County 915 Tenth Street, Room 317 Greeley, Colorado 80632 Re: Appendix to statement on behalf of Concerned Citizens of Weld County Dear Clerk: As per Adam Babich's letter to you of this same date, enclosed please find one set of the appendices to the statement on behalf of Concerned Citizens of Weld County regarding the application of Wixco, Inc. and Tire Mountain, Inc. for a biohazardous waste incinerator. Thank you for your assistance. Very truly yours, p 76/keVe4t-'4E-&Rebecca Greben Legal Assistant to Adam L. Babich 891508 I i EXHIBIT Ss APPENDICES to Statement on behalf of Concerned Citizens of Weld County Z O I- /0 �� \ •-• N0 0 0 0 Q1 H O a C a a a is. = V a) a 3 a a a O ' O J C C C 0 e O O Z Z 4.9.\ -J --I 0 0 LO Y 01 O VD CD 0 �-1 a C C N IC. M H 0 44- 44 '4- ^ J I- C Z - m , Q U 1 = { w W 0 0 0 0 0 0 0 0 CD 0 . O 0 O O 0 0 O a Q N 0 O 0 0 0 0 O Q Cl Z W I- In n to 0 0 0 O . E N NJ NJ 4 0 0 0 O F a 0 44 44 44 CO NJ In 1n -+ V 44 N N 9. 44 44 44 _ !n W W 6 W I- C I--. 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C 1 f L Lo 0 to to .- O C .- V) O 0 0 a) 1- OW 0 L Lrn to Cn f0 0 e CO a.) •.- CO C CM 0) N 3 0 Cn y .- I- .- to O) N , 4-) .- O to .-. a v) 01 N L 0) m 11 to >C a) r a .-• Co Co 3 C a • • • 0 .- N M a7 to up n r 4 4 Appendix A 890958 Hospital Waste Disposal by Incineration Waste Streams, Technology, and State Requirements Calvin R.Brunner and Courtney H. Brown CH2M Hill Reston,Virginia Table I is a listing of wastes classified as biomedical and Biomedical wastes are generated by hospitals, includes a description of each waste as well as typical charac- laboratories,animal research facilities,and by other teristics.The bag designations(red,orange,yellow,blue)are institutional sources. The disposal of these wastes is used in Canada. In the United States,generally all of these coming under critical public scrutiny,and regulations wastes are classified as"red bag." are being romul tad to control their disposaL The hospital waste stream has changed significantly in the promulgated P� last few years.Disposable plastics have been replacing glass Incineration is not a final disposal method since it and clothing in what appears to be,at first look,a means of generates a solid residue(ash)which must be buried or cutting costs.They represent a greater cost in their disposal, otherwise disposed. The incineration process,however, however,since many of these plastics contain chlorine and renders the waste non-toxic,non-hazardous,and non- with the increase in the use of plastics,the increase in chlo- rine and reduces the volume of material for creates the need for additional equipment in the incin- putrescible, eration process. The plastics content of the hospital waste ultimate disposal by an order of magnitude.In some stream has grown from 10 percent to over 30 percent in this ' instances, the residue may have high levels of heavy decade. metals;however, this is the exception rather than the It is rare to find an incinerator designated for biomedical rule waste destruction to be fired solely on this type of waste. Generally,particularly in hospitals,installation of an incin- erator encourages the disposal of other wastes in the unit. Besides the cost savings this represents in not having to cart Like many other institutions,hospitals are generating more this trash away,there is the potential for heat recovery.For and more waste with their increasing use of disposable prod- example,hospitals generally require steam throughout the ucts,and with an increase in the services that they perform year for their laundry,sterilizers,autoclaves,and kitchens. for the community. What is to be done with these wastes? As more waste is fired, more heat is produced and more Hospital wastes have been found washing onto public beach- steam is generated. es and uncovered in dumps scattered throughout the coun- Another set of wastes are those generated in hospital lab- try.In addition,the public is becoming increasingly alarmed oratories that are hazardous wastes under RCRA, the Re- by the presence of AIDS in our society and is increasingly source Recovery and Conservation Act.Table II lists some of concerned with the spread of the disease.They are not quite these wastes.If more than 220 lb/month of these wastes are sure that it is not set free in hospital waste accumulations. generated,the incinerator must be permitted under the pro- Many hospitals have incinerators.Generally,these incin- visions of RCRA,which are additional to state requirements. erators were installed over a decade ago,when minimal sten- Waste generation rates will vary from one hospital to dards existed for the design and operation of this equipment. another, a function of the number of hospital beds, the They were, and are, operated by people untrained in their number of intensive care beds, and the presence of other efficient use.Poor design and poor operation result in poor specialty facilities. In the absence of specific generation performance. So many of these units operate as bad neigh- data,the figures in Table III can be used as an estimate of bore,discharging soot,smoke and odor,that public opposi- waste generation rates. tion to this technology becomes understandable. This is the problem:the public wants effective disposal of Regulatory limes hospital wastes but they don't want to have to hear,see,or smell the mechanism for its removal and destruction. Biomedical waste incinerators are generally small, much smaller than the central disposal incinerators that have been The Waste Stream in the public eye in many of the densely populated areas of the country.Regulations have addressed these larger munic- "Biomedical waste"is a term coming into common usage ipal solid waste incinerators.Smaller units,such as 2-to 10- to replace what had been referred to as "pathological" or ton-per-day biomedical waste incinerators, have generally "infectious"wastes and to include additional related waste not been subject to rigorous regulatory attention in the past. streams.Where the term"pathologic waste"is used herein, it refers to anatomical wastes,carcasses and similar wastes. Copyright lase—APCA October 1988 Volume 38, No. 10 1297 Appendix B 890958 WASTE MANAGEMENT Table I. Characterization of biomedical waste(reference 1). Weighted Typical Typical Moisture heat value component component Bulk content of range heat value weight HHV density component of waste of waste Waste Component percent dry basis as fired (weight component as fired class description (as fired) (Btu/lb) (lb/ft3) percent) (Btu/lb) (Btu/lb) Al(red bag) Human anatomical 95-100 8000-12000 50-75 70-90 760-3600 1200 Plastics 0-5 14000-20000 5-144 0-I 0-1000 180 Swabs,absorbents 0-5 8000-12000 5-62 0-30 0-600 80 Alcohol,disinfectants 0-0.2 11000-14000 48-62 0-0.2 0-28 _,Q Total bag 1480 A2(orange bag) Animal infected Anatomical 80-100 9000-16000 30-80 60-90 720-6400 1500 Plastics 0-15 14000-20000 5-144 0-1 0-3000 420 Glass 0-5 0 175-225 0 0 0 Bedding,shavings, Paper,fecal matter 0-10 8000-9000 20-46 10-50 0-810 S1QQ Total bag 2520 A3a(yellow bag) Gauze,pads,swabs Garments,paper, Cellulose 60-90 8000-12000 5-62 0-30 3360-10800 6400 Plastics,PVC,syringes 15-30 9700-20000 5-144 0-1 1440-6000 3250 Sharps,needles 4-8 60 450-500 0-1 3-5 5 Fluids,residuals 2-5 0-10000 62-63 80-100 0-11 30 Alcohols,disinfectants 0-0.2 7000-14000 48-62 0-50 0-28 iii Total bag 9700 A3b(yellow bag)lab waste Plastics 50-60 14000-20000 5-144 0-1 6930-12000 9000 Sharps 0-5 60 450-500 0-1 0-3 0 Cellulosic materials 5-10 8000-12000 5-62 0-15 340-1200 650 Fluids,residuals 1-20 0-10000 62-63 95-100 0-100 30 Alcohols,disinfectants 0-0.2 11000-14000 48-62 0-50 0-28 20 Glass 15-25 0 175-225 0 0 _Q Total bag 9700 A3c(yellow bag)R&D Gauze,pads,swabs 5-30 8000-12000 5-62 0-30 280-3600 1000 Plastics,petri dishes 50-60 14000-20000 5-144 0-1 6930-12000 9000 Sharps,glass 0-10 60 450-500 0-1 0-6 0 Fluids 1-10 0-10000 62-63 80-100 0-200 100 Total bag 10100 B1(blue bag) Non-infected Animal anatomical 90-100 9000-16000 30-80 60-90 810-6400 1400 Plastics 0-10 14000-20000 5-144 0-1 0-20000 1000 Glass 0-3 0 175-225 0 0 0 Beddings,shavings, Fecal matter 0-10 8000-9000 20-46 10-50 0-810 f�QQ Total bag 3000 The only restriction on their operation in many parts of the In many cases,regulations are under review and are expect- country is that they not create a public nuisance. That has ed to change.The regulations for some states are much more meant that no odors are to be generated and that the opacity extensive than can be included in this document.The tele- is to be low,i.e.,no greater than Ringleman No. 1 for more phone number of the applicable agency in each state and the ! than, for instance, 5 minutes per hour. Incinerators have District of Columbia and Puerto Rico is included in this been designed to this standard, which is virtually no stan- listing.The state agency should be contacted for more com- dard at all.As public attention is starting to focus on hazard- plete and up-to-date information on regulations and the ous, dangerous, and toxic wastes, the regulatory attitude permitting process. towards biomedical waste incinerators is starting to change. These incinerators are not addressed by the federal govern- Hazardous Waste Incineration ment yet, but many states are moving in the direction of regulation.In some states these wastes are classified as haz- Where hazardous regulations must be complied with,the ardous;in others they are regulated as a unique waste stream incinerator design and operation must be subject to the with its own set of regulations; and in some states there is RCRA regulations for handling and disposal. Incineration still no regulation of biomedical wastes per se. regulations under RCRA require an extensive analytical and The Appendix lists the current status of state regulations compliance process.In addition to operating requirements, of biomedical waste incinerators in the United States today. the RCRA incinerator regulations mandateextensive re- 1298 90958 JAPCA 8 Table II. Hazardous wastes under RCRA typically air)demand is that ideal amount of oxygen(or air)required generated by in-hospital laboratories(from reference for complete combustion of the waste. Table IV lists the 2). heating values and stoichiometric air requirements for pies- Acetone Methyl alcohol tics,paper,and pathological waste.Note the high variability Anti-neoplastics Methyl cellosolve in these numbers. - Butyl alcohol Pentane No equipment is 100 percent efficient and this means that Cyclohexane Petroleum ether more than 100 percent of the ideal (stoichiometric) air re- Diethyl ether Tetrahydrofuran quirement is necessary to assure that the entire charge will Ethyl alcohol Xylene burn. This is "excess air" combustion where more air is provided to the charge than the stoichiometric requirement. Excess air incinerators will normally inject from 75 percent to 200 percent excess air in the burning chamber, i.e., the cordkeeping and reporting procedures.A detailed,compre- incinerator combustion air fans are sized to provide from 175 hensive operator training program must also be implement- percent to 300 percent of the stoichiometric requirement. ed. Pyrolysis refers to the heating of a combustible (organic) material in the absence of oxygen to promote a breakdown of Combined Hazardous Waste Systems organics to simpler compounds,such as in the manufacture of coke and synthetic natural gas from coal.The true pyroly- Hazardous waste incineration systems require a RCRA sis process adds either no air or only sufficient air to produce permit and strict operating controls and reporting stan- the heat required to promote the process.Under the applica- dards. Another significant issue associated with hazardous tion of heat the waste will dissociate into a gas and a solid waste incinerators is that the ash is always considered haz- residue,or char.The gas will be rich in organic matter and is ardous. Procedures exist for delisting ash (declaring ash fired in a separate afterburner. nonhazardous) but this requires extensive testing and ad- The main advantage of pyrolysis is a low air requirement. ministrative activity(filings and petitions)that represent at With little air passing through the waste there is less turbu- least 18 months of reporting and review. lence within the system and less particulate carryover from the burning chamber. This low air flow also results in very low nitrogen oxide generation,although this is not normally a concern in hospital incinerators.Less supplemental fuel is Table III. Estimated Waste generation rates required than with excess air systems where the entire air (reference 6). flow must be brought to the operating temperature of the Hospital 13 lb/occupied bed/day incinerator.With the lower air flow,fans,ducts,flues and air Rest home 3 lb/person/day emissions control equipment can be sized smaller than in Laboratory 0.5 lb/patient/day excess-air systems. Cafeteria 2 lb/meal/day Pyrolytic operation is almost impossible to obtain for two reasons. It is difficult to control air leakage into the system and it is not possible to determine an accurate waste heating value on which to base a definition of the stoichiometric air If,for example,1,000 lb of biomedical waste were inciner- ated,approximately 200 lb of ash would be generated. In a state not classifying such waste as hazardous,the ash could Table IV. Waste combustion characteristics. be deposited directly in a nonhazardous (municipal waste) landfill. If 100 lb of a hazardous waste were fired in the Waste constituent Btu/lb lb air/lb waste" secondary chamber of this same incinerator, all the ash would be considered hazardous and would have to be depos- Polyethylene 19687 16 ited in a hazardous waste landfill (unless it was delisted). Polystyrene 16419 13 Where 100 lb of hazardous waste was originally present,now Polyurethane 11203 9 at least 200 lb of hazardous waste must be disposed of.As a PVC 9754 8 general rule,it is impractical and uneconomical to incinerate Paper 5000 4 hazardous and nonhazardous waste in the same incinerator. Pathological 1000 1 'Stoichiometric requirement. Waste Combination Hospital wastes will contain paper and cardboard, plas- 1 tics,aqueous and nonaqueous fluids,anatomical parts,glass requirement(note Table IV).Starved air systems have been bottles,clothing, and many other materials. Most, but not developed which inject from 60 percent to 90 percent of the all,of this waste is combustible.Lighting a match to a mixed stoichiometric air requirement into the primary chamber of assortment of hospital waste will generally result in a sus- a furnace and burn out the off-gas in a secondary combus- tained flame. tion chamber, or afterburner with excess air. Starved air An incinerator is an enclosed chamber where heat is ap- combustion has essentially the same limitations of pyrolytic plied to raise the temperature of the charge to ignition and combination,but to a lesser degree. where air is injected to provide the oxygen needed for waste combustion.An incinerator must be able to supplement the Waste Destruction Criteria heat of combustion of the charge to raise the temperature of its products of combustion to the required temperature ley- Generally,paper waste(cellulosic materials)requires that el. a temperature of 1,400°F be maintained for a minimum of Thermal treatment technologies include pyrolysis and ex- 0.5 seconds for complete burnout. The temperature/resi- cess air combustion processes.The stoichiometric oxygen(or dence time requirement for biomedical waste destruction October 1988 Volume 38, No. 10 890958 1299 WASTE MANAGEMENT must be at least equal to the requirements for paper waste; Modular,Excaea Ak however,the specific relationship between temperature and residence time must be determined for the specific waste. A typical modular incinerator,commonly termed a"retort Some states require a temperature of 1,800°F maintained incinerator,"is shown in Figure 1.In this type of unit,waste for a minimum of one second. is fired in the primary chamber.The secondary combustion On the high temperature side, it is necessary to consider chamber provides the residence time,temperature,and sup- the general nature of much of the biomedical waste stream. plemental fuel for combustion of the unburned organics It has a high proportion of organic material,including cellu- carried over from the primary chamber.The incinerator is a losic waste.The noncombustible portion of this waste(ash) compact furnace in the form of a cube with multiple internal will begin to melt,or at least desolidify,as the temperature baffles.The baffles are positioned to guide the combustion increases.Table V lists the ash fusion temperature of refuse, gases through 90-degree turns in both lateral (horizontal) which represents the same constituents as much of the bio- and vertical directions.At each turn,ash(soot)drops out of medical waste stream.Above 1,800°F,the ash produced will the flue gas stream. The waste is charged on a batch basis and is allowed to burn out over a period of hours.A typical operation includes charging at the end of the day, waste Table V. Ash deformation temperatures from firing,and burnout by morning.The ash residual is cleaned refuse burning(reference 5). out of the incinerator prior to each day's charging. Air is injected into the primary and secondary combustion Reducing Oxidizing chambers through the supplementary fuel burners. Each atmosphere atmosphere chamber normally has one or two burners to provide the heat Condition (°F) (°F) required to bring the furnace up to operating temperatures Initial deformation 1880-2060 2030-2100 and to maintain its required operating temperature. Softening 2190-2370 2260-2410 The retort incinerator is not easily adaptable to automatic Fluid 2400-2560 2480-2700 or continuous operation. GAS begin to deform in a reducing atmosphere,i.e.,where there is DISCHARGE a lack of oxygen in the furnace.When ash starts to deform and then is moved to a cooler portion of the incinerator,or to -- an area of the furnace where additional oxygen is present, the ash will harden into slag or clinker.This hardened ash can clog air ports, disable burners, corrode refractory, and interfere with the normal flow of material through the fur- nace.To prevent slagging,the temperature within the incin- SECONDARY -\ ▪" erator should never be allowed to rise above 1,800°F.Higher COMBUSTION temperatures also encourage the discharge of heavy metals CHAMBER y to the gas stream,which is another reason not to impose an arbitrarily high temperature on the process. BURNER Incineration Technology w^'• • PRIMARY COMBUSTION There are two major types au"eER j of incinerators used for the FEED ' incineration of biomedical waste in the United States and Canada:the modular incineration unit and the rotary kiln. ' � ssnic . ASH Modular units are of two types, starved air and excess air. • 0 0 o o b o • DISCHARGE Rotary kiln systems include a secondary combustion cham- ber and are run as excess air units. PRIMARY COMBUSTION AIR PORTS Figure 2. Starved air Incinerator(reference 6). PRIMARY COMBUSTION CHAMBER ai STACK Modular,Starved Alr The starved air incinerator, shown in Figure 2, includes � two furnace chambers.In the primary combustion chamber, o6 SECONDAR N the waste is fired with less than the stoichiometric air re- g AIR PORT quirement.The off-gas is burned out in the secondary com- CE BDEARRY bustion chamber,where from 100 percent to 140 percent of ..... BURNER the stoichiometric air requirement is injected. At least one 4. : burner is required in the primary chamber to bring the at temperature of the chamber to the required operating tem- < ,,�, MIXING CHAMBER perature. Enough air is injected into the chamber, usually from 40 percent to 80 percent of the stoichiometric ASH Iii require- SECONDARY ment, to allow sufficient burning to generate the heat re- PRIMARY COMBUSTION quired by this process.Usually a primary chamber combus- COMBUSTION CHAMBER tion air fan with a flow control damper is provided to supply BURNER this air flow.Another fan,the secondary chamber air supply Figure 1. Retort incinerator(reference 6). fan with its own damper,is normally provided as a source of 1300 890958 JAPCA ADIABATIC TEMPERATURE OF A CELLULOSE WASTE Starved air furnaces are used as batch units or as either 2400 - semiautomated or continuously operating systems. In the batch unit mode,waste is charged and allowed to burn out 2200 before another charge is inserted.Semicontinuous operation utilizes a charging ram which may be cycled a number of I 2000 times in a day's operation. This incinerator may not have SECONDARY automatic ash removal and ash must be cleaned out daily. COMBUSTION In the continuous mode of operation,fired waste is loaded 1 CHAMBER 1800 into the charging hooper from two to six times per hour. A charging ram loads the waste into the furnace and as the 1600 PRIMARY waste enters the furnace chamber,it pushes waste previous- COMBUSTION ly charged towards the chamber exit, sometimes with an CHAMBER assist from intermediate charging rams.Ash removal is auto- 1400 mated in this type of system. The majority of starved air M incinerators in use today on biomedical applications are the ≤ 1200 semicontinuous type. I a V woo 800 SECONDARY COMBUSTION O CHAMBER 600 r 0 400 B Oin ROO CHARGING 1V. HOPPER 1. A -60 -40 -Ro 0 20 40 60 80 100 120 fi```n` EXCESS AN% C;'53 I,I' w,` Figure 3. Cellulose waste combustion(reference 6). IC` 1 V air for the secondary combustion chamber.A burner is pro- • vided to insure burning in the secondary combustion them- ROTARY KILN ASH DISCHARGE bar, and this burner is normally always firing, for mainte- nance of a flame in the chamber under any and all conditions of feed and operation. Figure 4. Rotary kiln system. The injection into the primary combustion chamber of only a fraction of the air required for full burnout produces relatively little carryover of particulate from the primary chamber.The higher the air flow into and around the waste, Rotary Kin the higher the entrained particulate carryover;the reduction of this carryover is an important feature of this system. The rotary kiln is a horizontal refractory lined cylinder Another feature of the starved air system is its control of that rotates about its horizontal axis,as shown in Figure 4. chamber temperature.When the waste is burning with the Waste is charged directly into the kiln. The rate of waste stoichiometric air (or oxygen) requirement, a maximum flow through the kiln is a function of the speed of the kiln, temperature will be reached. When the waste is fired with which is variable, and the rake, or angle of the kiln to the greater air flow than the stoichiometric requirement, the horizontal, which is normally fixed. Air in excess of the excess air will cool the gas stream. When the waste is fired stoichiometric requirement is provided to the kiln to burn with less than the stoichiometric air requirement,there will out the waste. be insufficient air to burn out all of the organics in the waste. A secondary combustion chamber is part of the kiln sys- When the unit is operating in the stoichiometric mode,the tem.Off-gas from the kiln contains volatiles from the waste greater the air supply,the higher the temperature,because that have not burned out,and distraction of these organics is as more air is injected into the process,more heat is released. completed in the secondary chamber.The waste is agitated These principles are illustrated in Figure 3. in the kiln by the rotating motion of the kiln,normally in the In the primary combustion chamber of a starved air incin- range of 1 to 3 rpm.As the waste is subjected to this turbu- erator, the air flow rate is automatically controlled by a lence,it is washed by air which encourages combustion.This thermocouple in the primary chamber. As the temperature turbulence, however, increases the particulate load to the increases, the air flow decreases, thereby stabilizing the flue off-gas.The kiln system generally requires more eaten- chamber temperature.Conversely,a damper controlling air sive air emissions control than the modular units.The kiln flow to the secondary combustion chamber will increase air system is a continuous system,i.e.,waste is continually fed flow as the secondary combustion chamber increases in tem- to the unit,normally with a charging ram. By the time the perature.For properly designed incinerators,this control of charge reaches the end of the kiln,it has burned out to an ash furnace operation is relatively simple and straightforward. which can be discharged dry or into a water quench. October 1988 Volume 38,No. 10 1301 890958 WASTE MANAGEMENT Past Practices tion chamber and if the temperature increases the incinera- tor is operating in the starved air mode. If the temperature Modular units have been popular in the past because of decreases,the incinerator is operating as an excess air unit, their relatively low cost.A major factor contributing to their i.e.,starved air operation is not occurring. cost advantage over rotary kilns and other equipment is that One must expect in the design of biomedical waste incin- they require no external air emissions control equipment to erators that,although the incinerator charge may be suffi- produce a fairly clean stack discharge. When properly de- ciently large to preclude swings from very high to very low signed and operated, they can achieve a particulate emis- heat value wastes,this is not always the case.It is likely that sions rate of 0.08 gr/dscf(corrected to 50 percent excess air). a single incinerator charge can contain a polystyrene mat- As new regulations are promulgated, however, lower emis- tress (and very little else) that will start to burn almost at sions limitations will make the use of baghouses or electro- once upon insertion into the incinerator. Likewise, since static precipitators mandatory,and the modular incinerator much of the waste charged into an incinerator is in opaque (with inclusion of control equipment in the system package) bags, the waste cannot be identified. A charge can consist will likely lose its price advantage over other systems. The almost wholly of anatomical waste, or animal carcasses, or higher cost of rotary kilns was due to their need for external liquid (aqueous)materials which have a very low heat con- air emissions control equipment and to inclusion of the drive tent.An incinerator must be designed for this certain varia- mechanism necessary for its operation. tion in waste stream quality. Of the incinerators on the market today, the starved air unit is least able to adapt to changes in waste constituents. Starved Alr Process Limitations Air Emissions Control The most important issue associated with starved air com- bustion is the nature of the waste. For any pyrolysis or Until recently most hospital incinerators were not re- starved air reaction to occur the waste must be basically quired to include separate air emissions control equipment. organic,and able to sustain combustion without the addition This is changing as more attention is being focused on incin- of supplemental fuel,a definition of"autogenous"combus- eration as a means of disposal of hospital wastes.Air emis- tion.Without sufficient heat content to sustain combustion sions of concern include particulate matter (soot and the concept of sub-stoichiometric burning has no meaning. smoke),inorganic gases(carbon monoxide,nitrogen,hydro- A waste with a moisture content in excess of 60 percent gen chloride,and sulfur oxides),organic gases(PCBs,diox- will not burn autogenously at 1600°F. As noted in Table I, ins,dibenzofurans),and metals. the moisture content of red bag, orange bag and blue bag While scrubbing systems and dry collection systems have wastes are generally in excess of this figure. Starved air been used on municipal waste incineration systems and in- combustion will not work when wastes with this moisture dustrial waste incinerators, there have been relatively few fraction are placed in the furnace. applications of these technologies to biomedical waste incin- Usually, a starved air incinerator is designed to fire a erators.This will change in time.The types of air emissions paper waste, and the burners in both the primary and sec- control systems that are being applied are described below. ondary chambers of the incinerator are sized appropriately: for a relatively small supplemental fuel requirement.When a bag of pathological waste is placed in the primary combus- Dry Impingement Separators tion chamber, the waste will not burn autogenously and Impingement separators are essentially a series of baffles supplemental fuel must be added. In most present starved placed in the gas stream.The relatively high inertia of par- air incinerator designs the burners have too low a capacity to ticulate within the gas stream will maintain their direction of provide the heat required when organics released by a flow while the gaseous component of the stream will change starved air process are not present. Without unburned or- its direction of flow around a baffle.Particulate matter will genies in the secondary chamber (when starved air has not drop and the gas flow will continue through the process occurred in the primary combustion chamber),the sizing of stream. the secondary burner is generally inadequate(the burner is This method of particulate removal can be effective for too small)to provide the fuel required for complete burnout larger particles,above 15 am,but smaller particulate matter of the gas stream. will continue to flow with the gas stream.They are used with On the other end of the operating range when a waste with other collection systems, removing larger particles from a a very high heating value is introduced (a plastic material gas stream to reduce the load on downstream control equip- such as polyurethane or polystyrene, for instance, as de- ment. scribed in Table IV)a good deal of air is required to generate even the sub-stoichiometric requirement necessary to gener- ate heat for the process to advance.This air quantity is often Dry Cyclonic Separators much greater than the air flow present from the fans provid- ed with the unit. The cyclone is an inertial separator. Gas entering the If a high quality paper waste(waste paper,boxes,cartons, cyclone forms a vortex which eventually reverses direction cardboard,etc.)is introduced into an incinerator,starved air and forms a second vortex leaving the cyclonic chamber. will generally work,assuming there is good control of infil- Particulate matter, because of their inertia, tend to move tration air.The incinerator should be designed,however,not toward the outside wall. They will drop from this wall,the for paper waste, but for the firing of a pathological waste, sides of the cyclone, to an external receiver for ultimate which requires a relatively large heat input and a coordinat- disposal. ed increase in air flow (primary and secondary combustion air and burner air fans)in both the primary and the second- Venturi Serubber ary combustion chambers. Starved air operation of an operating incinerator can easi- Venturi scrubbes are widely used,where water is readily ly be checked.Increase the air flow in the primary combus- available, as high-efficiency, high-energy gas cleaning de- 1302 JAPCA 890958 vices. The heart of the system is a wetted venturi throat Flue gases exiting the absorber are passed through a collec- where gases pass through a contracted area,reaching veloci- tion (or control) device, either an electrostatic precipitator ties of 200 to 600 feet per second,and then pass through an or a bag house. expansion section.From the expansion section the gas enters Particulate matter,hydrogen chloride, sulfur oxides and a large chamber where its velocity suddenly decreases.The organics are adsorbed on to the surface of the lime particles. higher inertia of the water particles throws them against the The lime sorbent, as well as any other particles within the bottom of the scrubber where they eventually exit the gas gas stream, are collected in a control device downstream of stream. the scrubber. Electrostatic Precipitator Electrostatic precipitators(ESPs)are effective devices for Air Emissions the removal of airborne particulate matter. The gas stream passes through a series of discharge electrodes that are nega- Arguments have been made by the general public that as tively charged.A negative charge is induced in the particu- long as a dangerous substance is emitted to the air from a late matter passing through the corona.A grounded surface, process,that process should cease.To carry this philosophy or collector electrode, surrounds the discharge electrode. to its extreme, where dioxins are concerned for instance, Charged particulate will collect on the grounded surface, would require a shut down of all coal-fired power plants, usually in the form of plate surfaces. Particulate matter is paper mills,all automobiles,would prohibit cigarette smok- removed from the collector surface by a series of rappers for ing,and would prohibit forest fires, all of which generate a collection and ultimate disposal. measurable amount of dioxins. The poison is in the dosage. A microgram of arsenic is Wet Electrostatic Precipitator harmless while two gallons of water in one sitting is probably fatal.The presence of a dangerous compound in a discharge Another method of cleaning plates from an ESP is to wet is not necessarily a danger if the quantity emitted is suffi- them down.Wet electrostatic precipitators have been devel- ciently small. A charcoal broiled steak will contain dioxins oped where sprays wet the incoming flue gas stream to a but the quantity is so small that the"danger"can be safely saturated or super-saturated condition.The electric charge ignored. is transferred to the liquid droplets and the liquid charges, Harmful emissions should be decreased to safe levels,and collects,and washes away particulate from the gas stream. many state agencies in issuing their construction and operat- ing permits define this level of safety for a number of constit- Fabric Filters uents. Typical constituents requiring control, their effects (at sufficiently high doses), and control of their emissions Fabric filters, or baghouses, are prevalent in all types of are noted as follows: industrial applications.They are essentially a series of per- • Particulate matter is measured in microns where 10 mi- meable bags which allow the passage of gas but catch panic- crone are visible as dust on a table top.Particulate may aisle matter, and utilize growth of caught particulate to be unburned organics or ash and will generally adsorb catch still smaller particles. They are effective for particle metals.Control of particulate is by an electrostatic pre- sizes down to the froron range. Collected particulate is cipitator, fabric filter or dry scrubber. While a signifi- periodicelly removed from the bags by a series of shaker cant portion of particulate matter may be controlled by mechanisms, by compressed air pulses, or by a number of wet scrubbing systems, organic matter is hydrophobic other methods. and will pass through a water based stream.The use of water for particulate control,therefore,must be careful- Wet Acid Gas Scrubbing ly evaluated. Acid gases in an incinerator exhaust generally refer to • Sulfur oxides have gross atmospheric effects such as hydrogen chloride and sulfur dioxide, from which hydro- plant damage,and can result in eye irritation and respi- chloric acid and(through the formation of the related com- ratory diseases such as emphysema and bronchitis.They can be controlled by wet scrubbing with an alkali solu- scrubbing pound, sulfur p ptrocess reduce)es sulfuric stheacid i s temperature ge of the gas The wet m tion or with a dry scrubbing system. esoc acidic c comp the sinne system.This stream • Nitrogen oxidesproducegross atmospheric effects such and removes components in one This system B P normally consists of a venturi scrubber,for particulate con- as smog and they can produce oxygen deprivation in the trol, followed by a tray tower or a packed tower. An alkali blood.Nitrogen oxides can best be controlled by efficient solution, (calcium hydroxide, Ca(OH)2, or caustic soda, combustion or ammonia-based injection systems. NaOH),can be circulated to the tower to wash acidic compo- • Carbon monoxide attacks red blood cells.At 1,000 ppm nents from the gas stream. it may be fatal. Carbon monoxide is controlled by effi- cient control of the combustion process. i Dry Scrubbing Systems • Polychlorinated biphenyls(PCBs)are classified as carci- nogenic and have been found to cause liver damage and Dry scrubbing used to remove acid gas components oper- chloracne.They can best be controlled by efficient com- ate as sorbent systems rather than as the washing systems bustion. Dry scrubbing will also remove them from the inherent in wet scrubber designs.An adsorbent(lime slurry) exhaust gas stream. is injected into the absorber(spray dryer) as a finely atom- • Mercury causes blindness, muscle deterioration, birth ized spray,producing droplets in the range of 30-100 µm in deformations,and death.It is controlled as a particulate. diameter.The absorber is sized to provide at least 10 seconds c is a carcinogen and a respiratory irritant. It is gas residence time.With this retention,and with appropri- • Arsenic a particulate• ate absorber geometry,water within the lime slurry is edapo- rated and does not come in contact with the reactor walls. • Cadmium is a carcinogen,causes cardiovascular disease, 1303 October 1988 Volume 38, No. 10 R5 f4Ssa WASTE MANAGEMENT and is extremely toxic to aquatic life.It is controlled as a (unburned organic materials).A wet scrubber will have particulate. little effect on these unburned particles and,in fact,may • Chromium is generated in the hexavalent state with ex- carry them through the stack to create a public nuisance cess air operation,and in the trivalent state in a reducing by promoting odor and particulate emissions.Water can atmosphere.Trivalent chromium has not been found to be used to quench a hot gas stream, but the stream be a significant danger to life while hexavalent chromi- temperature should not be allowed to decrease to the um is carcinogenic, causes respiratory disease, and is a point at which water is condensed. skin irritant.They can be controlled as particulate. If a significant quantity of hexavalent chromium is found in References ash or in the control device residual,however,additional processing is necessary to convert it to the trivalent 1. "Incinerator Design and Operating Criteria,Volume II,Biomedi- cal Waste Incinerators, Ontario Ministry of the Environment, form. October 1986. • Dioxins(dibenzo-p-dioxins)and furans(dibenzofurans) 2. B.W.Doyle,"The smoldering question of hospital wastes,"Pot- are related compounds which have been found to cause lotion Engineering,July 1985. chloracne in humans and are fatal to animals in extreme- 3. C. R. Brunner, "Biomedical Waste Incineration,"presented at the Mr Pollution Control Association Annual Meeting, New ly low dosages.They can be controlled through effective York,June 1987. combustion and with dry scrubbing systems. 4. "EPA Guide for Infectious Waste Management," U.S. EPA, • Hydrogen chloride is a lung and eye irritant and causes C.R.Brunner,r Incin. Y 5. New Incineration Systems:, 984. Selection&Design,Van gross atmospheric effects such as plant damage.It can be Nostrand Reinhold,New York,1984. removed from incinerator exhaust gases either by wet 6. C. R. Brunner, Hazardous Air Emissions from Incineration, scrubbing or by a dry scrubber. Chapman&Hall,Second Edition,New York,1986. 7. F.C. Powell,"Air pollutant emissions from the incineration of Summary hospital wastes,the Alberta experience,"JAPCA 37:836(1987). Properly designed incineration systems can effectively de- stroy hospital wastes. Incinerators with appropriate air emission control systems can be good neighbors. A number Appendix:State Requirements for incineration of of recommendations should be considered before purchasing Hospital Wastes an incinerator for biomedical waste: ALABAMA 1. Never specify an incinerator to a Type O waste standard. This so-called"standard"is part of a classification that There are mustno re be permitted by theally for hospital tm of incinerators. n- incinerators be permitted by the Department of Environmen- was developed years ago by an organization that no long- tal Management,Mr Division prior to installation.Incinerators with er exists.The designation Type O is for"trash,"defined a charging rate less than 50 ton/day may not discharge particulate as a material with 5 percent ash and 10 percent moisture matter at a rate greater than 0.2016/100 lbs refuse charged.Inciner- content.This is an idealized mateial that is not available ators with a charging rate greater than or equal to 50 ton/day may as a waste or as a test material.In lieu of this classifica- not discharge more than 0.116/100 lbs refuse charged.The discharge tion, which many manufacturers attempt to use in an may not exceed 20 percent opacity except during one six minute effort to standardize their product,use actual biomedi- period per hour when it may not exceed 40 percent.More stringent standards may be specified in the permit depending on the source cal waste analyses and characteristics,as included here location and other factors.For more information call the Depart- in Table I or in other literature. ment of Environmental Management,Mr Division in Montgomery 2. Design the system for no greater than 1,800°F tempera- at(205)271-7700. ture to prevent slag formation. ALASKA 3. Do not use a grate or an open hearth.Open surfaces may There are no regulations specifically for hospital incinerators.No not contain liquids or other portions of the wastes and permit is needed for incinerators with capacities smaller than 1000 full burn-out may not occur. lb/h. The only regulation governing these small incinerators is a 4. Avoid the starved air/pyrolysis process. With the ex- visual emissions standard of 20 percent opacity.New regulations for trams variation inherent in biomedical waste feeding, incinerators have been proposed. For more information call the Department of Environmental Conservation,Air and Solid Waste the stoichiometric requirement is constantly changing. Management Section in Juneau at(907)465-2666. It is virtually impossible for a starved air process to be ARIZONA maintained when the stoichiometric air demand ratio There are no regulations specifically for hospital incinerators.All ranges from less than 2 to greater than 15. If utilized, incinerators must have two permits:an air quality permit and a solid provide positive air locks. A dual lock system, or its waste permit. All incinerators must meet a particulate emissions equivalent,should be utilized to prevent air from enter- standard of 0.1 grains/dscf (corrected to 12 percent C02) and a ing the incinerator during the changing cycle. The ash visual emissions standard of 20 percent opacity.For more informs- discharge system should also be designed to minimize tion call the Department of Environmental Quality, Air Quality spurious air leakage into the system.Also,provide suffi- Section in Phoenix at(602) 257-2277 and Solid Waste Section at cient capacity in burners and fans to operate in the (602)257-6989. excess air mode when necessary. ARKANSAS 5. Excess air systems,modular or rotary kiln types,should There are no regulations specifically for hospital incinerators.All be used for the incineration of biomedical waste streams. incinerators must be permitted. Incinerators with capacities less These wastes are too variable for sub-stoichiometric sys- than 20016/6 may not emit more than 0.3 gr/dscf(corrected to 12 tems to be effective. percent C02)and larger incinerators may not emit more than 0.2 gr/ 6. Carefully evaluate the use of wet scrubbers forgas clean- dscf(corrected to 12 percent CO2). The visual emissions may not exceed 20 percent opacity. For more information call the Depart- ing.The majority of particulate discharging from a bio- ment of Health,Divison of Health Facility Services in Little Rock at medical waste incinerator will likely be carbonaceous (501)661-2201. 890958 Cep 1304 JAPCA ' CALIFORNIA waste incinerators and these requirements are usually written into There are no regulations specifically for hospital incinerators.Air air pollution permits. Secondary chamber temperature and reten- quality is regulated by Air Quality Management Districts and regu- tion time are frequently specified by districts.All incinerators must ',rations vary from district to district.All districts require incinera- be permitted.For incinerators with capacities less than 50 tons/day tors to be permitted. Each district has particulate,visual,and air the visual emissions standard is 5 percent opacity and there is no toxics emission standards. The air toxics emissions requirements particulate emissions standard. The regulations are expected to are highly dependent on the location of the facility and vary signifi- become more stringent within the next six months.For more infor- cantly from district to district.There are many other requirements. mation call the Department of Environmental Regulation, Solid If the incinerator treats wastes generated offsite it must be permit- Waste Planning and Regulation Program in Tallahassee at (904) , ted by the State Health Services Department.For more information 488-0300. call the California Department of Health Services,Hazardous Ma- terials Management Section in Sacramento at(916)324-9611. There are no regulations specifically for hospital incinerators. COLORADO Incinerators must be of multiple chamber design. The primary There are no regulations specifically for hospital incinerators.All chamber must reach 800°F before charging and the secondary incinerators must be permitted.Particulate emissions may not ex- chamber must be at least 1500°F. Incinerators handling less than ceed 0.1 gr/dscf(corrected to 12 percent CO2).The visual emissions 500 lb/h may not emit more than 1 lb/h of particulate matter. standard is 20 percent opacity. Guidelines for hospital wastes re- Incinerators handling 500 lb/h or more may not emit more than 0.2 quire a secondary chamber temperature of 1800°F with a retention lb/100 lb charged.The visual emissions standard is 20 percent opaci- time of two seconds. If offsite wastes are treated a certificate of ty.For more information call the Department of Natural Resources, designation is required by the Solid Waste Management Depart- Air Quality Section in Atlanta at(404)656-4867. ment.Proposed regulations,which include air toxics emissions lim- its,will probably go into effect in lat 1989 or early 1990.For more HAWAII information call the Department of Health,Air Pollution Control There are no regulations specifically for hospital incinerators. Division in Denver at(303)331-8591. Permits are required for all new or modified incinerators.Require- ments, including secondary chamber temperature and retention CONNECTICUT time,are determined on a case by case basis and specified in the There are guidelines for hospital incinerators. All incinerators permits. For small incinerators particulate matter emissions may must be permitted.Incinerators are required to meet BACT(best not exceed 0.2 lb/100 lbs refuse charged and the opacity may not available control technology)standards which include the following exceed 20 percent.Contact the Department of Health for the defini- for hospital incinerators:particulate emissions may not exceed 0.15 tion of small incinerators.All of the hospital incinerators in Hawaii gr/dscf(corrected to 12 percent C02);there must 90 percent reduc- are small.For more information call the Department of Health,Air tion of hydrogen chloride or less than 4 lb/h hydrogen chloride and Solid Waste Permit Section in Honolulu at(808)548-6410. emitted,whichever is less;carbon dioxide emissions may not exceed 100 ppmdv(corrected to 7 percent O2);and the combustion efficien- IDAHO cy must be at least 99.8 percent.In addition,the primary chamber There are no regulations specifically for hospital incinerators.Air temperature must be at least 1800°F and the secondary chamber pollution permits are required for all incinerators.Requirements for temperature must be at least 2000°F with a retention time of at least hospital incinerators are determined on a case by case basis and two seconds.The visual emissions may not exceed 10 percent opaci- specified in the permits.The particulate emissions limit is 0.216/100 ty.There are other requirements including monitoring and record- lbs refuse charged and the visual emissions standard is 20 percent ing procedures.For more information call the Department of Envi- opacity.The Hospital Facilities Section has proposed new regula- ronmental Protection,Solid Waste Management Unit in Hartford tions for hospital incinerators.For more information on air pollu- at(203)566-5847. tion permits call the Department of Health and Welfare,Air Quality Bureau in Boise at(208)334-5898 and for information on the pro- DELAWARE posed regulations call the Hazardous Material Bureau at(208)334- There are no regulations specifically for hospital incinerators.All 5879 incinerators must be permitted by the Air Quality Section of the Department of Natural Resources and Environmental Control.In- ILLINOIS cinerators must be double chambered with a secondary chamber There is a rule specifically for hospital incinerators. Require- temperature of at least 1400°F.The visual emissions standard is 20 ments include obtaining an air pollution control permit and special percent opacity.Other requirements,including a higher secondary ash disposal procedures. The air quality regulations apply to all chamber temperature, are usually specified in the permit. Other incinerators. The particulate emissions standard for incinerators permits may be required depending on the source location.Coastal with capacities less than 2000 lb/h is 0.1 gr/dscf(corrected to 12 Zone, Wetlands, or water pollution regulations may apply. The percent CO2). Carbon monoxide emissions may not exceed 500 Solid Waste Section is drafting regulations for infectious waste ppmdv. Other requirements, including secondary chamber tem- incinerators.For more information call the Department of Natural perature and retention time,are determined on a case by case basis Resources and Environmental Control, Air Resources Section in and specified in the permits.For more information call the Environ- Dover at(302)323-4558. mental Protection Agency, Division of Air Pollution Control in DISTRICT OF COLUMBIA Springfield at(217)782-2113. There are specific air pollution control requirements for patholog- INDIANA ical waste incinerators. Incinerators must be of multiple chamber There are no regulations specifically for hospital incinerators.All design.Particulate emissions may not exceed 0.03 gr/dscf(corrected incinerators must have air pollution control permits. Particulate to 12 percent C02). Pathological waste incinerators may only be emissions standards depend on the size of the incinerator and loca- opereted between the hours of 10:00 A.M.and 4:00 P.M.Two inter- tion of the facility. The visual emissions standards depend on locking devices are required—one that prevents operation of the whether the facility is in an attainment or nonattainment area for primary chamber when the secondary chamber outlet is less than particulate matter.All incinerators must be multiple chamber.The 1800°F and another that prevents operation of the primary chamber secondary chamber temperature must be at least 1800°F with a when the primary chamber charging door is not closed.There are retention time of 1 second.If anti-neoplastics are treated the reten- several other requirements.For more information call the Depart- tion time must be at least 1.5 seconds.There are also monitoring and ment of Consumer and Regulatory Affairs,Environmental Control recording requirements.By the end of 1988 new solid waste rules Division at(202)767-7370. with additional requirements will be in effect.For more information FLORIDA call the Department of Environmental Management,Office of Solid There are no statewide regulations specifically for hospital incin- and Hazardous Waste Management in Indianapolis at (317) 232- erators; however, some districts do have guidelines for infectious 8842 and the Office of Air Management at(317)232-8459. 1305 October 1988 Volume 38, No. 10 890958 WASTE MANAGEMENT IOWA MASSACHUSETTS There are no regulations specifically for hospital incinerators.All There are no regulations specifically for hospital incinerators.All incinerators must be permitted. Incinerators with a capacity less incinerators must be permitted.BACT analysis is carried out on a than 100 lb/h may not emit more particulate matter than 0.35 gr/ case by case basis to determine the specifics of each permit.Each dscf(corrected to 12 percent CO2)and those with larger capacities incinerator must go through performance testing.The particulate may not emit more than 0.2 gr/dscf(corrected to 12 percent CO2). emissions limit is determined on as part of BACT,but would never The opacity may not exceed 40 percent. Emissions testing during exceed 0.02 gr/dscf(corrected to 12 percent CO2).The visual emis- startup is required.Operators must evaluate the emissions for many sions standard is 20 percent opacity.If the incinerator has a capacity contaminants including particulates, polyaromatic hydrocarbons, larger than 1 ton/hr then it must be permitted by the local authori- chlorinated hydrocarbons, dioxins, furans, and metals. Other re- ties as well.For more information call the Department of Environ- quirements are determined on a case by case basis and specified in mental Quality,Division of Air Quality Control in Boston at(617) the permits.For more information call the Department of Natural 292-5619. Resources,Air Quality Section in Des Moines at(515)281-8935. MICHIGAN KANSAS All incinerators must be permitted.The term"pathological"re- Two permits are required for hospital incinerators:a solid waste fers to carcasses and body parts whereas"infectious"refers to other processing permit and an air quality permit.There are many solid contaminated wastes including needles and plastic containers. In- waste processing requirements including waste handling and stor- fectious waste incinerators must have a minimum secondary chain- age,and ash disposal requirements.Air quality regulations include ber temperature of 1800°F with a retention time of one second. particulate emissions standards which range from 0.10 to 0.30 gr/ There is no temperature requirement for pathological incinerators. dscf(corrected to 12 percent CO2)depending on the capacity of the All incinerators must meet particulate standards which depend on incinerator.The visual emissions standard is 20 percent opacity.For the incinerator capacity and air toxics in the emissions.There are more information call the Department of Health and Environment, many additional requirements. Offsite facilities must be part of a Solid Waste Management Section in Topeka at(913)296-1590 and county waste management plan.For more information call Depart- the Air Quality and Radiation Section at(916)296-1572. ment of Natural Resources,Air Quality Division in Lansing at(517) KENTUCKY 373-7023. There are no regulations specifically for hospital incinerators. MINNESOTA Permits are required for incinerators larger than 500 lb/h or inciner- There are no regulations specifically for hospital incinerators. ators that emit significant amounts of air toxics.The limits for air Permits are required for incinerators with capacities greater than toxics emissions are based on site location,stack height,the contam- 1000 lb/h.The particulate emissions standard is 0.2 gr/dscf(correct- inant,and several other factors.The particulate standard for incin- ed to 12 percent CO2)for incinerators with capacities less than 200 erators with capacities less than 50 ton/day is 0.1 gr/dscf(corrected lb/h, 0.15 gr/dscf (corrected to 12 percent CO2) for incinerators to 12 percent CO2). The standard for larger incinerators is 0.08 rated between 200 lb/h and 2,000 lb/hr,0.10 gr/dscf(corrected to 12 grains/dscf(corrected to 12 percent CO2).Incinerators that do not percent CO2)for those rated between 2,000 lb/h and 4000 lb/hr,and require permitting are exempt from the particulate standard.The 0.08 gr/dscf(corrected to 12 percent CO2) for larger incinerators. visual emissions standard is 20 percent opacity.For more informa- The visual emissions limit is 20 percent opacity. The regulations tion call the Cabinet of Natural Resources, Air Quality Permit state that the secondary chamber temperature must be at least Branch in Frankfort at(502)564-3382. 1200°F with a retention time of 0.3 seconds,however,higher tem- LOUISIANA peratures and longer retention times are specified in permits.These well as other requirements are determined on a case by case basis. There are no regulations specifically for hospital incinerators. Permits are required for all incinerators.All requirements are deter- Proposed regulations are expected to be final in 1.5 to 2 years.For mined on a case by case basis and specified in the permits.Typical more information call the Pollution Control Agency,Division of Air Quality in Roseville at(612)296-7711. requirements for hospital incinerators are a minimum secondary chamber temperature of 1800°F with a retention time of 1 second,a MISSISSIPPI visual emissions standard of 20 percent opacity and a grain loading There are no regulations specifically for hospital incinerators.All limit.There are proposed regulations for hospital incinerators that incinerators must be permitted. Incinerators must be of multiple will probably be final by March 1989.For more information call the chamber design. The particulate emissions standard is 0.1 gr/dcsf Department of Environmental Quality, Office of Air Quality and (corrected to 12 percent CO2)in residential or developed areas and it Nuclear Energy in Baton Rouge at(504)342-1201. is 0.2 gr/dscf(corrected to 12 percent CO2)in remote areas.Other MAINE requirements,including air toxics emissions limits,are determined There are no regulations specifically for hospital incinerators; on a case by case basis and specified in permits.For more informa- however,there are BPT (best practical technology) guidelines for tion call the Bureau of Pollution Control,Air Section in Jackson at hospital incinerators.The secondary chamber temperature must be (601)961-5171. at least 1800°F with a retention time of one second.If anti-neoplas- MISSOURI tics are treated with secondary chamber temperature must be at All incinerators must be permitted.Infectious waste incinerators least 2000°F with a retention time of two seconds.The particulate must have a minimum secondary chamber temperature of 1800°F emissions rate may not exceed 0.1 gr/dscf(corrected to 12 percent with a retention time of 0.5 seconds.This temperature requirement CO2). Opacities in excess of 10 percent may trigger a stack test does not apply to pathological incinerators.The particulate emis- requirement. There are other requirements. There are proposed sions standard is 0.3 gr/dscf(corrected to 12 percent CO2)for incin- regulations which are expected to be final in late 1988.These regula- erators smaller than 200 lb/h and 0.2 gilded(corrected to 12 percent tions will formalize the guidelines currently used.For more informa- CO2) for larger incinerators. Visual emissions may not exceed 20 tion call Department of Environmental Protection,Bureau of Air percent opacity.There are special requirements for offsite facilities. Quality Control in Augusta at(207)289-2437. The regulations will be revised within one year.For more informs- i MARYLAND tion call the Department of Natural Resources,Air Pollution Con- , There are no regulations specifically for hospital incinerators.All trot Program in Jefferson City at(314)751-4817. incinerators must be permitted.A Full air toxics analysis is required MONTANA during permitting as well as a stack test after construction. The There are no regulations specifically for hospital incinerators. secondary chamber temperature must be at least 1800°F with a Permits are required for incinerators that process more than 25 ton/ retention time of two seconds. The particulate emission rate may yr.Incinerators must be multiple chamber.Particulate matter emis- not exceed 0.1 gr/dscf(corrected to 12 percent CO2)and no visual sions may not exceed 0.1 gr/dscf(corrected to 12 percent CO2)and emissions are allowed(0 percent opacity).For more information call the opacity may not exceed 10 percent.All incinerators must meet the Department of Environment,Air Management Administration BACT(best available control technology).Permit requirements are in Baltimore at(301)225-5260. determined on a case by case basis.For more information call the 1306 JAPCA 890958 Department of Health and Environmental Sciences, Air Quality The particulate emissions limits are based on refuse charging rate lureau in Helena at(406)444-3454. and are determined by a graph established by the State.The partic- ulate standard is 0.5 lb/h for a charging rate of 100 lb/h or less and NEBRASKA about 12 lb/h for a charging rate of 4,000 lb/h.The visual emissions There are no regulations specifically for hospital incinerators. standard is 20 percent opacity.The regulations are more stringent Incinerators with capacities less than 1 ton/h may not emit particu- for facilities in New York City,Nassau,and Westchester Counties. late matter at a rate greater than 0.2 gr/dscf(corrected to 12 percent Regulations for hospital incinerators have been drafted and will CO2).Larger incinerators may not emit more than 0.1 gr/dscf(cor- probably be effective in February 1989.For more information call rected to 12 percent CO2). Visual emissions may not exceed 20 the Department of Environmental Conservation, Division of Air percent opacity. Incinerators must meet BACT if they emit more Resources in Albany at(518)457-2044. than 2.5 ton/yr of any of 309 specified contaminants.Other require- ments, including secondary temperature and retention time, are NORTH CAROLINA written into permits.These requirements are determined on a case There are no regulations specifically for hospital incinerators.All by case basis.For more information call the Department of Environ- incinerators must be permitted.The particulate emissions standard mental Control,Air Quality Division in Lincoln at(402)471-2189. for incinerators with capacities less than 100 lb/h is 0.2 lb/h.The NEVADA particulate standard for incinerators rated between 100 lb/h and There are no regulations specifically for hospital incinerators.All 2,000 lb/h is 0.002 times the amount charged in lb/h.Incinerators incinerators must be permitted.The particulate emissions standard with larger capacities may not emit more than 4 lb/h.Visual emis- for incinerators with capacities less than 20001b/h is 3 lb/ton dry sions may not exceed 20 percent opacity for more than 6 minutes per charge.The allowable particulate emissions rate for larger incinera- hour. For more information call the Department of Natural Re- tors,e(lb/h),is determined by the following formula: sources and Community Development,Air Quality Section in Ra- leigh at(919)733-3340. e=(40.7 X 10-5)c, where c is the charge rate in pounds per hour.The visual emissions NORTH DAKOTA standard is 20 percent opacity.The secondary chamber temperature There are no regulations specifically for hospital incinerators. must be at least 1400°F with a residence time of 0.3 seconds.There Incinerators must be permitted.The allowable particulate emission are also air toxics emissions limits.A county commission permit is rate,e,is determined by the following formula: required and is often difficult to obtain.For more information call e=0.00515(R°5), the Department of Conservation and Natural Resources,Division of where R is the refuse burning rate in lb/h.Visual emissions may not Environmental Protection in Carson City at(702)885-5065. exceed 20 percent opacity.The regulations state that the secondary NEW HAMPSHIRE chamber temperature must be at least 1500°F with a retention time There are no regulations specifically for hospital incinerators. of 0.3 seconds, however, more stringent requirements are usually Hospital incinerators with capacities greater than 2001b/h must be written into permits.A minimum secondary chamber temperature permitted.An air quality analysis is required during the permitting of 1800°F and a retention time of 1 second are usually specified. process.Incinerators with capacities less than or equal to 200 lb/h There are no restrictions on air toxics emissions.For more informa- ' may not emit particulate matter at a rate greater than 0.3 gr/dscf tion call the Department of Health, Air Quality Management (corrected to 12 percent CO2)and visual emissions may not exceed Branch in Bismarck at(701)224-2348. 20 percent opacity. There are numerous requirements for larger OHIO incinerators including secondary chamber temperature and reten- There are no regulations specifically for hospital incinerators.All tion time and air toxics emissions limits. These requirements are incinerators must have a permit that meets BAT (best available determined on a case by case basis and specified in the permits.For technology)requirements.Incinerators with capacities less than 100 more information call the Department of Environmental Services, lb/h may not emit more than 0.2 lb particulate matter per 100 lb Division of Air Resources in Concord at(603)271-1390. charged and larger units may not emit more than 0.1 per 100 lb NEW JERSEY charged.The maximum opacity allowed is 20 percent.The second- There are no regulations specifically for hospital incinerators. ary chamber must be at least 1600°F. Incinerators may not emit Each incinerator msut be part of the State Solid Waste Manage- more than 4 lb of hydrogen chloride per hour. There are several ment Plan and be permitted as a solid waste facility. additional requirements.The BAT policy will be revised in the near The regulations state that the secondary chamber temperature future. For more information call the Environmental Protection must be least 1500°F with a residence time of one second.The state Agency,Division of Air Pollution Control in Columbus at(614)644- requires"state of the art air pollution control equipment"which is 2270. defined in Department of Health Guidelines.These guidelines in- OKLAHOMA dude a minimum secondary chamber temperature of 1800°F and a There are no regulations specifically for hospital incinerators. particulate emissions limit for incinerators with capacities larger permits are required for all incinerators. Incinerators must be of than 800 lb/h of 0.010 gr/dscf(corrected to 7 percent O2). Many multiple chamber design with a primary chamber temperature of at other requirements are determined on a case by case basis and least 800°F.The particulate emissions standards vary depending on specified in the permits.New regulations have been proposed and the charge rate.Visual emissions may not exceed 20 percent opacity are expected to go into effect in early 1989.For more information for more than five minutes in an hour and not more than 20 minutes call the Department of Environmental Protection,Bureau of Engi- in 24 hours. New regulations for hospital incinerators have been nearing and Regulatory Development in Trenton at(609)984-0491. proposed and will probably go into effect by May 1989.For informa- NEW MEXICO tion call the Department of Air Quality Service in Oklahoma City at There are no regulations specifically for hospital incinerators.A (405)271-5220. permit is required for incinerators that emit any criteria pollutant at OREGON a rate greater than 10 lb/h for controlled emissions and greater then There are no regulations specifically for hospital incinerators.All 100 lb/h for uncontrolled emissions. Visual emissions may not ex- incinerators must have an air pollution permit. In addition,if the ceed 20 percent opacity. Registration of air taxies emitted above incinerator accepts offsite wastes a solid waste permit is required. certain levels is required.Other requirements are determined on a The secondary chamber temperature must be at least 1600°F.Visu- case by case basis end specified in the permits.For more informs- al emissions may not exceed 20 percent.Particulate emissions limits tion call the Health and Environment Department, Air Quality and other requirements are determined on a case by case basis and Bureau in Santa Fe at(505)827-0070. specified in the permits.The maximum particulate emission limit NEW YORK ever allowed is 0.1 gr/dscf(corrected to 12 percent CO2) for small There are no regulations specifically for hospital incinerators. incinerators.New incinerator regulations have been proposed.For Incinerators must be permitted. Incinerators with capacities of more information call the Department of Environmental Quality, 2,000 lb/h or greater must meet particulate emissions standards. Air Quality Division in Portland at(503)229-5186. October 1988 Volume 38,No. 10 1307 890958 WASTE MANAGEMENT PENNSYLVANIA TEXAS Both air quality and waste management permits are required for All incinerators burning general hospital waste must be permit- hospital incinerators.There are BAT requirements for hospital in- ted. Incinerators with capacity less than 200 lb/h burning only cinerators. Facilities with capacity less than or equal to 500 lb/h carcasses and body parts,blood and nonchlorinated containers do must meet a particulate emissions standard of 0.08 gr/dscf(correct- not need permits.Incinerators must be of dual chamber design with ed to 7 percent O2).Facilities rated between 500 lb/h and 2,0001b/h a secondary chamber temperature of at least 1800°F and a retention must meet a standard of 0.03 gr/dscf(corrected to 7 percent O2)and time of one second. The visual emissions standard is 20 percent larger facilities must meet a standard of 0.015 gr/dscf(corrected to 7 opacity.If hydrogen chloride emissions exceed 4 lb/h,the incinera- percent O2). Hydrogen chloride emissions from incinerators with tor must be equipped with a scrubber.Other requirements,includ- capacities less than or equal to 500 lb/h must not exceed 4 lb/h or- ing air toxics emissions limits,are determined on a case by case basis shall be reduced by 90 percent.Hydrogen chloride emissions from and specified in the permits. For more information call the Air larger incinerators may not exceed 30 ppmdv(corrected to 7 percent Pollution Control Board, Combustion Section in Austin at (515) O2)or shall be reduced by 90 percent.Carbon monoxide emissions 451-5711. may not exceed 100 ppmdv (corrected to 7 percent O2). Visual emissions may not exceed 10 percent opacity for a period or periods UTAH aggregating more than three minutes in any hour, and may never There are no regulations specifically for hospital incinerators.All exceed 30 percent opacity. There are many other requirements new air pollutions sources must be permitted.All sources must meet including secondary chamber temperature,ash residue testing,and BACT.Requirements,including air toxics emissions limits,second- monitoring and recording procedures.For more information call the ary chamber temperature and retention time,and particulate stan- Department of Environmental Resources, Bureau of Air Quality dards,are determined on a case by case basis and specified in the Control at(717)787-9256 and the Bureau of Waste Management in permits.For more information call the Department of Health,Bu- j Harrisburg at(717)787-1749. reau of Air Quality in Salt Lake City at(801)538-6108. I PUERTO RICO VERMONT There are no regulations specifically for hospital incinerators.All There are no regulations specifically for hospital incinerators. incinerators must be permitted. An environmental impact state- The secondary chamber temperature must be at least 1600°F with a went is required for all facilities.The particulate emissions stan- retention time of one second.The particulate emissions standard for dard for incinerators with capacities less than 50 ton/day is 0.4 lb/ incinerators with capacities smaller than 50 ton/day is 0.1 lb/100lb 100 lb refuse burned.Visual emissions may not exceed 20 percent refuse burned.The amount of refuse burned is equal to the amount opacity.There are additional requirements.For more information charged minus the amount of ash generated.The standard for larger call the Environmental Quality Board,Air Quality Area in San Juan incinerators is 0.08 gr/dscf(corrected to 12 percent CO2).The visual at(809)722-0077. emissions may not exceed 20 percent except for six minutes per hour when they may not exceed 60 percent opacity.Guidelines for hospi- RHODE ISLAND tal incinerators call the Agency of Natural Resources,Air Pollution There are no regulations specifically for hospital incinerators.All Control Division in Montpelier at(802)244-8731. incinerators must be permitted. Single chamber incinerators may not be used.Hazardous material incinerators must need a particu- VIRGINIA late emissions standard of 0.08 gr/dscf (corrected to 12 percent There are no regulations specifically for hospital incinerators. CO2).For more information call the Department of Environmental Two permits are required for hospital incinerators:a waste manage- Management, Division of Air and Hazardous Materials in Provi- ment permit and an air quality permit.All incinerators must be of dence at(401)277-2808. multiple chamber design.Particulate emissions may not exceed 0.14 gr/dscf(corrected to 12 percent CO2). Visual emissions may not SOUTH CAROLINA exceed 20 percent opacity except for one six-minute period per hour There are no regulations specifically for hospital incinerators, when they may not exceed 60 percent. There are also monitoring however, there is a hospital incinerator policy which all new or and reporting requirements as well emissions limits for air toxics. modified units must comply with. Incinerators must be of dual New regulations for infectious waste management have been pro- chamber design. The secondary chamber temperature must be at posed.For more information call the Department of Air Pollution least 1800°F with a retention time of two seconds.The visual emis- Control in Richmond at(804)786-5478. sions standard is 10 percent opacity.New regulations for hospital incinerators are expected to go into effect in one year. For more WASHINGTON information call the Department of Health and Environmental Con- There are no regulations specifically for hospital incinerators.All trol,Bureau of Air Quality Control in Columbia at(803)734-4750. incinerators must meet BACT(best available control technology). The particulate emissions standard for incinerators with capacity SOUTH DAKOTA less than 250 ton/day is 0.030 gr/dscf(corrected to 7 percent O2)and There are no regulations specifically for hospital incinerators. the particulate standard for larger incinerators is 0.020 gr/dscf(cor- Permits are required for incinerators with capacities larger than 100 reefed to 7 percent O2). Hydrogen chloride emissions may not ex- i lb/h.The particulate standard for incinerators with capacity greater ceed 50 ppmdv(corrected to 7 percent O2)and sulfur dioxide emis- than or equal to 50 ton/day is 0.18 gr/dscm(corrected to 12 percent sions also may not exceed 50 ppmdv (corrected to 7 percent O2). CO2).There is no particulate missions standard for smaller incinera- Visual emissions may not exceed 10 percent opacity. The average tors.Visual emissions may not exceed 20 percent opacity.For more secondary chamber temperature must be at least 1800°F and tem- information call the Department of Water and Natural Resources, perature may never be less than 1600°F.For more information call Office of Air Quality and Solid Waste in Pierre at(605)773-3153. the Department of Ecology, Air Quality Program in Olympia at (206)459-6256. TENNESSEE There are no regulations specifically for hospital incinerators.All WEST VIRGINIA incinerators must be permitted.The particulate emissions standard There are no regulations specifically for hospital incinerators.All is 0.2 percent of the charging rate for incinerators with capacities incinerators must be permitted.The particulate emissions standard less than or equal to 2,000 lb/h and 0.1 percent of the charging rate for incinerators with capacities less than or equal to 15,000 lb/h is for large incinerators.Visual emissions may not exceed 20 percent 5.43 lb/ton burned and for larger incinerators thestandard is 2.72 opacity. Other requirements,including air toxics emissions limits lb/ton burned. Opacity may not exceed Ringleman No. I except and secondary chamber temperature and retention time,are deter- during six minutes per hour when it may not exceed Ringleman No. mined on a case by case basis and specified in the permits.For more 2. Other requirements are determined on a case by case basis and information call the Department of Health and Environment,Divi- specified in the permits.Generally the secondary chamber tempera- sion of Air Pollution Control in Nashville at(615)741-3931. ture must be at least 1600°F with a retention time of 0.5 seconds.If 1308 890958 JAPCA anti-neoplastics are treated a higher temperature is specified,usual- WYOMING ly 1800°F. For more information call the Air Pollution Control There are no regulations specifically for hospital incinerators.All Commission in Charleston at(304)348-4022. incinerators must be permitted.Two stage combustion is required. Incinerators must meet BACT(best available control technology). WISCONSIN The particulate emissions standard is 0.2 lb/100 lb refuse charged. All infectious waste incinerators must be permitted.The particu- Visual emissions may not exceed 20 percent opacity.For more infor- late standard for incinerators with capacities less than 200 lb/h is mation call the Department of Environmental Quality,Air Quality 0.08 gr/dscf(corrected to 7 percent O2).This standard also applies Division in Cheyenne at(307)777-7391. to infectious waste incinerators with capacities no greater than 400 lb/h which are operated no more than six hours per day.The partic- ulate standard for incinerators rated between 2001b/h and 1000 lb/h is 0.03 gr/dscf(corrected to 7 percent O2)and the standard for larger . incinerators is 0.015 gr/dscf(corrected to 7 percent O2).Incinerators ' larger than 200 lb/h may not emit more than 50 ppmdv hydrogen i chloride or 4 lb/h,whichever is less restrictive.All incinerators must I Ms.Brown and Mr.Brunner are consulting engineers with limit carbon monoxide emissions to 75 ppmdv.The visual emissions I CH2M Hill,P.O. Box 4400,Reston, VA 22090. This paper standard is five percent opacity. Stack testing is required for all was submitted for peer review March 16, 1988;the revised facilities. For more information call the Department of Natural manuscript was received August 26,1988. Resources,Air Management Bureau in Madison at(608)266-7718. Hospital Red Bag Waste An Assessment and Management Recommendations David Marrack Fort Bend Medical Clinic Houston,Texas of these ideas has led to our current Chlorinated plastics(PVC)accounted for 9.4 percent of the weight of"red "blind"acceptance that hospitals liar- bag,"supposedly infectious, waste from two community 150-and 98-bed bor highly infectious wastes and in or- hospitals. The hydrochloric acid, dioxins and furans generated during the der to protect society from the scourge of infectious diseases, these "deadly" burning of this red bag waste are important air pollutants.In this waste, wastes must be promptly burned! PVC provides much of the organic chloride for the dioxins and furans It is common practice for hospitals to generated. Their concentrations are least in flue gases from those plants have their own incinerators located ad- with BACT design,flue gas clean up and management techniques—the most jacent to the hospital. Such hospitals constrained incinerators. The many manually-fed,small categorical red bag are often located within communities in the United States and across much incinerators associated with hospitals have no flue gas clean-up systems and of the world. These incinerators burn represent minimally constrained incinerators. Their toxic stack emissions almost everything that leaves a hospi- are considered a significant community health hazard. The evidence that tea operating rooms and much else as the contents of red bag waste is infectious to such a degree that it cannot be well. Our pre-packaged, non-recycling disposed of as municipal solid waste without endangering the public with infrastructure leads to the discarding infectious diseases is not reflected in the relevant hospital accreditation of substantial amounts vinof chlorine-con- infectious plastics, polyvinyl chloride guidelines, Centers for Disease Control recommendations,or related (PVC),in the red bag waste. literature.Public health is compromised by the lack of accountability in the Two classes of air pollution are pro- handling of some hospital and veterinary wastes,specifically body fluid duced from the interactions of chlo- contaminated equipment and containers as well as microbiological rine, from chlorinated hydrocarbons, in the hot gases during and after the materials. Recommendations to protect public health are included. The burning process.One is the generation most important of these is a manifest system of cradle-to-grave of dioxins and furans in small but sig- accountability for a limited portion of a hospital's waste. nificant quantities by public health cri- teria. Hydrochloric acid is the second "Red bags,"the special colored plastic ceptual cause of infectious disease undesirable derivative.The concentra- bags designated for containing suppos- spread was debunked along with "evil tion of these toxic air pollutants in flue edly infectious waste,reflect one of the humors"by the mid-nineteenth centu- gas is least when BACT(Best Available relics of medical"wisdom,"the concept ry with the understanding: (1) of the Control Technology and refers to glob- that fomitese spread disease.This con- germ theory of infectious disease put ally available technologies) is used in forth by Pasteur,Koch and others and plant design,flue gas clean-up,ash and 'romitas((o'ml tez):pl.Any substance that absorbs and (2) through epidemiological studies. transmits infectious material.sing.:tomes(fa meal.T°- Another concept,exorcism by fire,has barb CyclopedicMedical Dictionary,F.A.Dame Co.,Phil- adelphia.PA. an even more venerable origin.A blend Copyright 1988—APCA October 1988 Volume 38, No. 10 896953 1309 a e • ►. r" 's . . •• _._.. - ti 11 i 44. t 1,102 MODERN INFECTIOUS WASTE INCINERATION SYSTEMS Hit 44 „^s:y Dorota Z. Przewalaka MSS ENGINEERING 6 MANUFACTURING COMPANY, INC. <.a Broad Brook, Connecticut The potentially hazardous nature of infectious wastes and the low energy content of pathological wastes imposes certain constraints on the design of incineration systems for their disposal. • The location of these incinerators in heavily populated areas, in or near hospitals, requires the application of stringent air pollution controls. Regulatory requirements governing the design, construction and operation of infectious waste incinerators are becoming as complex as hazardous waste disposal regulations. The need to locate these incinera- tors within existing facilities also imposes certain size restrictions. ` Since most infectious waste incinerators are small in size compared to their counterparts in the municipal and industrial waste disposal arena, they do not share the benefits of the economies of scale associated with these systems. µr This paper discusses the MSS MCI Revolving Chamber (Rotary Kiln) �;. Incineration System, designed especially for the economical and environmen- tally sound thermal treatment of pathological and infectious wastes. An automatic ram feeder minimizes the possibility of operator or equipment exposure to infectious agents. Heat recuperators are used to minimize auxiliary fuel requirements. State-of-the-art pollution abatement equip- ment limits emissions to below regulatory requirements and • sophisticated continuous monitoring system ensures safe and efficient system operation. This paper discusses the requirements of a modern infectious waste incineration system and the design of a system meeting these requirements. Two case studies, incorporating unique designs conforming to space restric- tions, are used to illustrate the principals involved. 298 6 890958 Appendix C 1 • i I Advantages of Infectious Waste Incineration Incineration Pathogen Destruction and Volume Reduction. The primary objective of infectious waste incineration is the destruction of the infectious agents present in the waste. An important secondary objective is to maximize the volume reduction of the waste to minimize final waste disposal require- ments. For many waste streams incineration offers a significant reduction in the volume, mass and weight of the waste. This reduction can be as much as 95 percent. Although a small amount of residue may remain and still need to be disposed of, since there is less waste being landfilled, and what is being landfilled is usually non-toxic, the liabilities and future problems associated with landfills are reduced or eliminated. Incineration is especially advantageous for processing pathological wastes and contaminated sharps because it makes body parts unrecognizable and sharps unuseable. Environmentally Acceptable. Burning wastes in a properly designed and operated incineration system, equipped with appropriate air pollution controls, results in the permanent disposal of a large category of wastes. Since the only products released into the atmosphere are carbon dioxide and water, this method is also environmentally acceptable. Established Technology. Incineration is an established technology. There is a large amount of both theoretical and practical data that exists on the handling of various types of waste streams by incineration. The operating and control parameters are well known and process efficiency and consistency can be verified and controlled. Cost Competitive. Incineration of infectious waste is becoming cost competitive with alternative disposal methods, especially as regulatory, environmental and real estate concerns make landfill disposal more dif- ficult, or in some cases, impossible. I� Applications This paper focuses on rotary kiln incinerators, such as the MCI, ranging in capacity from 3 million Btu per hour to 50 million Btu per hour. These incinerators are capable of handling many types of waste streams, including solids, liquids or sludges and are appropriate for hospitals, nursing homes, veterinary facilities, medical laboratories, commercial diagnostic laboratories, industrial plants, biotechnology companies and commercial waste disposal facilities handling infectious wastes. ** Depending on the size and application requirements, MCI systems can be stationary, transportable or mobile. On-site incineration eliminates the coats and risks associated with the transport of infectious wastes. Mobile systems are appropriate wherever temporary disposal facilities are required. System Design Criteria In designing an incineration system for processing infectious wastes, certain criteria must be met to ensure complete waste destruction together with safe and efficient system operation. The following summarizes the features required of a modern infectious waste incineration system. 299 890958 • • a • I fS V. Waste Feeding Mechanism ' U The waste feeding mechanism must minimize operator and equipment expo- sure to infectious agents. Thus, solid wastes should be fed, packaged, directly into the incinerator without shredding or any other pre- processing. Additionally, this mechanism must provide a lockout feature ..' which would cease the feeding process if chamber temperatures were too low. Y, ° J Y i Incineration Chambers i The incineration chambers must be capable of handling the high tem— peratures required to process the plastic content often found in today's infectious waste stream. The primary chamber should be sized to accommodate variations in waste stream composition: low density/high heating value (plastics) and high density/low heating value (tissues, bones) wastes. It is essential for this chamber to operate under negative pressure to prevent fugitive emissions. Depending upon the waste, operating temperatures should nor- ' - mally range from 1200 to 1800°F when processing infectious wastes. p. The secondary or combustion chamber temperature should normally exceed ';l 2000°F and sufficient excess air must be provided to ensure complete waste decomposition. i Pollution Abatement fi The air pollution control system must be capable of achieving the par- ticulate and chemical pollutant (HC1) capture efficiencies required by applicable regulations. Monitoring and Control The monitoring and control system must ensure that the temperatures required for complete pathogen destruction are maintained during the entire process. Emissions (e.g., CO in the flue gases) should be continuously monitored to verify process effectiveness. Any deviation from acceptable parameter settings should automatically terminate waste feed. ' Energy Recovery When processing low energy value pathological wastes, the use of heat recovery equipment is recommended to minimize auxiliary fuel costs. Case Studies Two case studies, the MRI-10-S Incineration System and the MRI-05-M X. Mobile Incineration System, are described herein. The MRI-10-S stationary #.c"r installation shown in Figure 1 and the MKI-05-M mobile unit shown in Figure 2 are two examples of systems which fulfill the criteria for a modern infectious waste incineration system. Typical stationary MEI system capacities range from 3 to 50 million Btu per hour; typical mobile MRI system capacities range from 5 (single trailer) to 20 (multiple trailer) million Btu per hour units. Both of these systems were designed to minimize physical space requirements while providing maximum processing capacity and incorporating comprehensive state-of-the-art air pollution controls. 300 ill 890958 rrw... MKI-10-S Incineration System Figure 1 shows an incineration system designed for the processing of infectious wastes. This compact, ten million Btu per hour unit is located inside an office park and includes all of the necessary equipment to pro- perly dispose of infectious wastes. This system is equipped with -an automatic ram feeder to handle pre-packaged solid wastes; -auxiliary fuel combustion system; -ignition chamber; -automatic ash removal system; -combustion chamber; -heat recuperator to minimize auxiliary fuel consumption; -pollution abatement equipment including a pumplesa venturi scrubber, a packed-bed scrubber, heat exchangers and a water conditioning system; -exhaust fan and stack; and -monitoring and control equipment. A discussion of each of the components listed above is presented in the later sections of this paper. Figure 1 MKI-10-S Incineration System • a,— • 1114 42. r1 rip'11 If • MKI-05-M Mobile Incineration System The mobile system seen in Figure 2 is transported intact and can be in operation within a few hours after arriving at a site. This complete, com- pact system is designed for processing hazardous wastes and has a capacity of 5 million Btu per hour. The entire system is mounted on a single 45 foot low-bed trailer. 301 890958 BB Figure 2 MKI-05-M Mobile Incineration System a.tt • i �w.�..r�w.n... i z: .. s p+ -. 113/4'.. This trailer houses -multiple feeding systems capable of handling solids, liquids and sludges; -a revolving ignition chamber; -ash removal system; -a combustion chamber; -pollution abatement equipment including a pumpless venturi scrubber, a packed-bed scrubber, heat exchangers and a water conditioning system; 1 -an exhaust fan end hydraulically-operated exhaust stack; -a computerized monitoring and control system, including all analytical equipment required to fulfill regulatory require- • requirements; and -an electric power generator. This mobile unit, designed for processing hazardous wastes, is equipped with the same air pollution control system as the unit shown in Figure 1 • and as the following test results indicate, the system is capable of meeting the strictest EPA emission standards. MRI-05-M Test Burn In September of 1986, the unit shown in Figure 2, underwent a three day emission test program performed by an independent testing laboratory. The following sections, Purpose of Testing, Method and Conditions of Testing, and Test Results are quoted from the test report. Purpose of Testing "The purpose of the emission test program was to demonstrate the ability of the incinerator to destroy a principal organic hazardous consti- 302 890958 91 ,.4= tuent (POHC) in a liquid waste feed and comply with EPA incinerator performace standards. Measurements performed on process streams, utilizing EPA reference and protocol methods, verified the unit to be in compliance with Federal regulations. Also demonstrated in this teat burn was a quick set-up and preheat time for the incinerator which was cold-started at the beginning of each test day. Mechanical problems associated with the MKI-05-M were rare and minor which facilitated the completion of testing in three days."1 Method and Conditions of Testing "This waste fuel, containing 20 percent by volume of dichlorobenzenes as the POHC was the only waste feed utilized in this burn. Dichlorobenzenes are difficult to burn and are considered to be a good surrogate for polychlorinated biphenyls (PCB's). Incinerator conditions were also held unchanged throughout the three days of testing. Kiln tem- perature was 950°C, secondary combustion chamber was 1200°C, excess air was 6-8% oxygen end scrubber water pH was maintained at 7-10."1 Test Results The MKI-05-M was tested for DRE of dichlorobenzenes, HC1 and par- ticulate emissions and concentrations of NOx, CO, CO2 and 02. ORE of Dichlorobenzene. "DRE was measured to be 99.9999 percent effi- cient for all three tests conducted on September 18, 1986. Total feed rate 4 of dichlorobenzene (DCB) was determined from the known composition of the synthetic waste and the fuel tank weight change recorded from the load cell at five minute intervals during the test. An average DCB feed of 19.5 pounds per hour was calculated from this data during the DRE testing. Results from the gas chromatography/flame ionization detector (CC/FID) analysis of the extracts of three Modified Method 5 (MM5) tests performed at the stack and similar analysis of the scrubber water for dichlorobenzene determined the quantity of the waste POHC which was not destroyed in the incinerator. Both ortho and meta dichlorobenzene emissions were detected in the stack with emission rates ranging from .99x10-5 to 1.59x10-5 pounds per hour. All samples were blank corrected. Dichlorobenzenes in the scrubber water were non-detected which corresponded to a rate of less than .13 x 10-5 pounds per hour. Compared to the 19.5 pounds per hour of DCB's inputed to the incinerator, all tests demonstrated greeter than 99.9999 percent DRE."1 HC1 and Particulate Emissions. "Results from three EPA Method 5 tests conducted on September 16 and 17, 1986, for particulates with the beck half collected and analyzed for HCL with the mercuric-nitrate titration, were all in compliance with EPA incinerator performance standards. Particulate emission concentration was .033, .017 and .015 grains per dry standard cubic foot (DSCF) for the three tests conducted. Compliance with the EPA Incinerator Performance Standard of .08 grains/DSCF corrected to 7% oxygen was met. HCL emmission rate measure .009, .005 and .004 pounds per hour for the three tests. This pollutant emission rate was also in compliance with the federal standard of 4.0 pounds per hour."1 Concentrations. "All CEM instruments measured concentrations in a flue gee sample drawn from a point in the exhaust system between the afterburner outlet and the scrubber inlet. 303 890958 eqr, 3n uMf�wn,»_. liWWW� • • Carbon monoxide was non-detected over the entire burn. Detection limits of the CO analyser were determined to be 1.0 part per million. Analog strip chart recordings of the data, included in the Appendix, displays a steady reading of zero. Carbon dioxide concentration ranged from 9.4 to 12.2 percent and oxygen ranged from 6.2 to 8.1 percent. Oxides of nitrogen were monitored only on September 18 and concentrations ranged from 111 to 136 parts per million."I Incineration Fundamentals The key factors involved in determining the appropriate incineration system for the required application--such as the physical and chemical reactions during incineration, proper analysis of the waste stream and identification of applicable regulatory requirements--are briefly described herein. Combustion Reactions During the burning process, several physical and chemical reactions occur. In the physical sense, burning is the joining of carbon atoms with oxygen atoms from the air to form carbon dioxide with associated heat generation. As shown in Figure 3, incineration converts combustible materials into carbon dioxide, water, and some residue composed of the noncombustible com- ponents of the waste stream. The carbon dioxide, water, and nitrogen from the air are released into the atmosphere through the stack. Figure 3 Combustion Equation. INPIDS TO TIE COMBUSTION PROFESS IL. OUTPUTS FROM TIE COBUS1ION PRDCESS WASTE AUXILIARY FILL AIR RELEASED INTO ---> ATNOSPIERE 4. CAPTURED POLLUTANTS +MEAT Carbon (C) 79% Nitrogen (N2) Carbon Dioxide (CO2) Bromine (Br2) Steam Hydrogen ((H) 21% Oxygen (02) Water (H20) Iodine (I2) Hot Water Nitrogen (N2) Sulfur Oxides (50x) Hot Air (Percentages given Oxygen (02) Nitrogen Oxides (N0x) Other Elements: above are by volume. n Chloride Chlorine (Cl) Water vapor, carbon Hydrogen Fluoride (IF)) Fluorine (F) dioxide and tram Bromine (Br) compounds are not PhospMetals 55 Metals (P205) Metals ye Iodine (I) considered.) oxials Sulfur (5) Metal MeHytal Oxides Phosphorous (P) [0.0318% Carbon Oxides Metals Dioxide (CO2) in (etc.) clean, dry air) The noncombustible component elements in the waste stream must usually be captured by an air pollution control system. Most commonly, the air pollution control system must be able to remove particulate and inorganic acids such as sulfur oxides or hydrochloric acid. Figure 3 identifies some possible pollutants that may need to be scrubbed from the exhaust gases. 304 890958 � v f.. A I The nature of the air pollution control system is dictated by the com- • position of the waste stream. The waste stream also dictates the required system capacity, the appropriate feeding mechanism, necessary auxiliaries, etc. Basically, proper analysis of the waste stream is critical in designing the entire system so that it is the best possible configuration for the application. Waste Stream Analysis To properly analyze the waste stream, three major issues must be addressed: physical waste characteristics, energy characteristics and che- mical composition. ayilissiSIIII _Characteristics. First, the form of the waste must be identified. The physical characteristics of the waste will determine the type of waste feeding mechanism required. . Energy Char t t' Second, the energy be quantified to determine the auxiliary fuelrequirements the waste equirements and to establish whether special equipment, such as a heat recuperator for high water con- tent wastes or a cooling system for exothermic wastes is required. Chemical Composition. Finally, the waste is required to identify the understanding lofu the composition will of generated and thus, the type types of pollutants that will be required. of air pollution control system that is Determining the composition and energy content of the waste stream will also help identify opportunities for mixing waste streams to reduce auxi- liary fuel requirements or air pollution control system loading. Infectious Wastes Wastes capable of producing an infectious disease are considered infec- tious. For a specific waste to be infectious it must contain pathogens of sufficient quantity and virulence to infect a host exposed to the waste. Reliance on disposable items has made hospital facilities and medical laboratories major generators of solid, often infectious, waste. The com- ponents of this waste stream are varied, ranging from disposable nightgowns to broken syringes to discarded blood products. The categories of wastes identified as infectious by the Environmental Protection Agency (EPA) are summarized below. Isolation Wastes. - Wastes generated by patients who are isolated to protect others from communicable diseases. Cultures. Cultures and stocks of infectious agents such as discarded vaccines, from medical research or industrial laboratories, and any asso— ciated dishes or devices used with the cultures. Blood Products. Discarded blood, serum, plasma and other blood pro— ducts. Pathologic l W Tissues, etc. removed during surgery, autopsy, biopsy, etc. Contaminatedimals Carcasses, body parts or body fluids and any associated materials of animals that were exposed to pathogens. 305 880958 • • « S. 4.7 Contaminated Materials and Equipment. Needles, syringes, scalpel bla- des, glass, dressings, surgical clothes, laboratory coats, sheets and, • potentially, any equipment used in patient care, laboratories or in the production of some pharmaceuticals. The regulations for disposal of hospital and laboratory wastes-- especially the infectious portion of this waste stream--are currently being reviewed in light of increasing landfill disposal costs and health and environmental impact concerns. There are no Federal regulations and there is no general consensus among state and local laws regarding either the definition or disposition of this waste stream. Current practices range from treating these wastes as part of the general municipal waste stream to s' treating them as special or hazardous wastes. Since incineration is an ,? effective method of destroying the pathogens present in infectious wastes, many states promote or require the incineration, sometimes on-site, of all i infectious wastes. Typical Incineration System for Processing Infectious Waste The major subsystems included in a typical infectious waste incinera- tion system--waste feeding mechanisms, auxiliary fuel combustion system, ignition chamber, ash removal system, combustion chamber, optional energy recovery equipment, pollution abatement equipment, exhaust fan and stack, and monitoring and control equipment--are described herein. The process overview and flow diagram shown in Figure 4 is a good example of a typical infectious waste incineration system and it includes all of the above-mentioned major subsystems. Specifically, Figure 4 pre- Bents the process and flow of the MKI-10-S Incineration System shown in Figure 1. Waste Feeding Mechanisms Many factors must be considered when selecting a feeding system, such "k- as waste quantity, consistency, physical characteristics containers, etc. For example, when processing infectious wastes, certain feeding methods, such as those requiring material shredding prior to feeding, should be avoided; the chosen feeding method should limit the feeding mechanisms' exposure to infectious agents. Infectious wastes such as pathological wastes are usually packaged in ' containers such as plastic bags. The waste handling mechanism must be able to feed the bags or containers directly into the ignition chamber without exposing the operator or equipment to infectious agents. Ram feeders are the most appropriate feeding method in this case as they allow the automatic feeding of irregularly shaped or packaged solid wastes into the incinerator without pre-processing and without disturbing the combustion process. Auxiliary Fuel Combustion System The auxiliary fuel combustion system consists of individual burnersmounted to the outer she lle of the ignition and combustion chambers. ,r,„r Individual or dual-fuel burners can be used; either natural ie usually used es the auxiliary fuel. The ae burners operate gas in conj uncr fuel l[ion with the combustion air blower(s) and include the appropriate piping, safeties and controls. 306 ill ". 890958 i Figure 4 NKI-10-S flow diagram sod process overview. EXHAUST STACK AUXILIARY I FUEL COMBUSTION AIR FAN Is , SECONDARY Z COMBUSTION HEAT CHAMBER FLUE IECUPER_ I PRECOOLER FLUE (CC) "LAS-. AMRGAS RE • 1 FLUE GAS FLUE GAS HOT AIR PUMPLESS 1ENTURI REVOLVING SCRUBBER RAM FEEDER_. IGNITION (demister) \ / • CHAMBER WPM (RIC) CONDITIONING PACIE D_BEO 4 `i' SYSTEM SCRUBBER f. 1- — _ SLUDQ AUXILIARY I ASHI CAUSTIC 6 WATER &L WATER UE S , FUEL , PIEIIATING the hot combustion air is supplied to the The Auxiliary Fuel Combustion System (RIC burners; thus, increasing oxygen avail- burner C3 and CC burner) preheat the Ignition ability for combustion and reducing the and Combustion Chambers to their proper detrimental flame retarding effects of operating temperatures. burning high water content wastes. RIDING POLLUTION ABATEMENT j The Ram Feeder is used for feeding irreg- The flue gases from the Heat Recuperator ularly shaped or pre-packaged solid are drawn through the Precooler section of wastes into the incinerator without pre- the Flue Gas Cooler/Reheater prior to processing end without disturbing the entering the PV Scrubber. Precooling gases combustion process. reduces steam formation, ensures efficient PROCESSING scrubbing end reduces the possibility of the RIC burner Rignites the waste's cos- damage to internal scrubber parte. bustible The precooled gases enter the PV Scrubber components and initiates the for particulate removal. Particulate and ' burning process. Auxiliary fuel is gases are separated, the particulate is supplied during operation, if necessary, collected and released in the scrubber to maintain the process temperature. Same solution and the gases enter the Packed- thermal degradation of the waste takes Bed Scrubber where acid gases and place in the Ignition Chamber. As the aubaicron particulate are absorbed. chamber rotates, new waste surfaces are Before exhausting into the atmosphere, exposed to ensure complete waste destruc- these gases enter the Reheater section of tion. The waste, is decomposed into vole- the Flue Gas Cooler/Reheater. Reheating ' tilired gases and ash. The ash gases to temperatures above their dew (noncombustible solids) is continuously point eliminates condensation in the discharged into the Ash Bin while the flue exhaust fan and stack and reduces steam gases (smoke and particulate) flow upward plume. Steam plumes over the exhaust to the Combustion Chamber. The CC burner stack may be mistaken for smoke which maintains the Combustion Chamber's high would indicate improper system operation. operating temperature. This chamber le MONITORING &CONTROL provided with sufficient excess air to The monitoring and control system ensures accomplish complete oxidation. Complete safe and efficient system operation. The thermal destruction of the wastes occurs entire incineration system is monitored by in this chamber. various temperature, pressure, flow and FEAT IECDVLRY chemical sensors located throughout the The hot gases from the combustion process unit. The date recording capabilities enter the Heat Recuperator and exchange required to fulfill hazardous waste — heat with the incomaing combustion air. regulations are also provided. 307 890958 i `,,,. _ ...._�..amw,� a ay 'slit 1 • • 'lefts .. • AI The auxiliary fuel combustion system is used to preheat the equipment, ignite the waste and initiate the burning process. Auxiliary fuel and com- bustion air is supplied during operation, as necessary, to maintain the process temperature and provide sufficient excess air to accomplish complete oxidation. The action of the burners and the use of the fuel depends on the incoming waste stream's characteristics. Ignition Chamber The revolving ignition chamber is a cylindrically shaped, refractory- lined shell mounted at a slight incline from the horizontal plane. It is fabricated from welded steel plates and lined with a high density, abrasion resistant, tastable refractory. High temperature alloy anchors secure the refractory to the shell. Tracks, welded to the outer shell, guide the wheels which rotate the chamber. The speed and direction of rotation are controlled by an appropriate drive assembly. An inspection door is provided for access to the chamber and, if necessary, manual ash removal. An auxiliary burner, mounted in the wall of the ignition chamber, is used to preheat the chamber to its proper operating temperature. Once pre- heated, waste materials are fed into the chamber and the burner ignites the materials' combustible components. Depending on the process materials, chamber temperatures range from 1200 to 1800°F. Within this high temperature air, the materials are decomposed into volatilized gases and ash. The gas is drawn into the combustion chamber for complete oxidation and the ash remains in the ignition chamber. As the chamber rotates, breaking up the insulating ash layer, new surfaces are exposed to the thermal process. During this process, material continually moves over the refractory lining, which retains the desired preset tem- perature. This, in addition to the controlled overfire air conditions, allows continuous, safe and complete material burning. During operation, ash is slowly transferred to the opposite end of the chamber and continually discharged into an ash or conveyor bin. Chamber rotation accomplishes waste transport through the chamber and enhances waste and combustion air mixing. Ash Removal Systems The discharged ash can be either manually or automatically transferred to suitable disposal containers. In most cases, automatic transfer from the bin to the container is regdired. Depending on the application, either an Auger Ash Conveyor or Slat Ash Conveyor is generally used. The Auger Ash Conveyor is suitable for trans- ferring fine ash; the Slat Ash Conveyor is suitable for transferring ash containing small particles which require wet collection. Following analy- sis, final ash disposal would typically be to a sanitary landfill. Combustion Chamber A refractory-lined duct directs the flow of volatile gases from the ignition chamber to the combustion chamber. In most cases, the combustion chamber, a cylindrically-shaped steel shell, is fabricated from rolled steel plates and lined with a high temperature, medium density tastable refractory secured to the chamber by alloy steel anchors. 308 890958 t The combustion chamber (afterburner) is perhaps the simplest of the major system components yet it is the most critical with respect to the destruction of toxic hydrocarbons. Sufficient excess air must be provided to complete oxidation of the smoke's combustible components (any unburned hydrocarbons from the ignition chamber). Consequently, the combustion chamber can be thought of as either the second combustion stage or a com- ponent of the air pollution control system. Combustion chamber temperatures are frequently higher than ignition chamber temperatures. Depending on the material being processed, tem- peratures should normally exceed 2000°F. The CC burner is positioned so that the incoming gases and particulate pass through the high velocity excess air flame. The direction of the flame assures a swirling, vortex action which provides maximum turbulence and residence time to the burning mass. Auxiliary fuel is proportioned into the burner, as required, during system operation. • Optional Energy Recovery Equipment Heat Recuperators. Since water retards burning, a substantial quan- tity of auxiliary fuel is required when processing high water content wastes. In this case, a heat recuperator is installed to reduce auxiliary fuel consumption. The recuperator is a heat exchanger installed in the path of the hot exhaust gases, for instance at the base of the exhaust stack or between the combustion chamber and pollution abatement equipment. The recuperator is comprised of tubes which are mounted across the exhaust duct and connected to flow directing manifolds. Combustion air is blown through these alloy tubes and heated by exchanging heat with flue _ gases exiting the combustion chamber. Special burners which operate with hot combustion air and require less fuel to maintain the necessary high flame temperature are used. This method increases oxygen availability for combustion and reduces the detrimental flame retarding effects of burning high water content waste. A property designed exchange system can reduce fuel consumption by up to 50 percent. In some instances, heat derived even from burning high water content wastes, including pathological wastes, can be enough to sustain combustion within the required temperature limits. Pollution Abatement Equipment Air pollution control systems are concerned with minimizing emissions of acid gases and particulate. In addition to federal standards, various state and local regulations may apply. Although these regulations may vary, the allowable emission levels are very low and optimum scrubbing efficiency is essential. MSS designs and manufactures various types of pollution abatement equipment, including the patented PV (pumpless venturi) Scrubber, Packed Bed Scrubbers and Baghouses. Each of these systems may serve indepen- dently, or in conjunction with the others, depending on the type of pollutant(s) that must be removed. PV and Packed Bed Scrubbers (wet scrubbing) are used when chemical pollutants (e.g. chlorine) must be removed; Baghouses (dry filtration) are used when particulate collection is the only objective. Auxiliary equip- ment (Flue Gas Cooler/Reheater, Water Conditioning System) is provided, as required, to enhance operation of the air pollution control system. ' 309 890958 1 • • • • Its . 1 The high efficiency PVH Scrubbing System, illustrated in Figure 5, is also included in the systems shown in Figures 1 and 2 and is an e pollution abatement system when processing infectious wastes. ppropriate PVH Scrubbin¢ System The PVH Scrubbing System consists of a Flue Gas Cooler/Reheater, patented PV (pumpless venturi) Scrubber, Packed Bed _. Scrubber and Water Conditioning System. The PVH Scrubbing System features r, low maintenance requirements, low energy consumption and high scrubbing efficiency. JR` The flue gases pass through the Precooler section of the Flue Gas ' hot Cooler/Reheater, which is a flue gas to water indirect heat exchanger. The gasesheat with e Flue Ga Cooler/Reheater/Reheater exchange s and travel through ththe e [transfer ool wat educt to the thPV scrubbers Precooling gases prior to scrubbing minimizes steam bubble formation which occurs when hot gases make contact with cool scrubber solution, thus possibly allowing a portion of the gases to escape without being scrubbed. The PV scrubber is designed to capture pollutants, from the flue within the scrubber solution. Process gases enter ergases, th intake tube and travel downward. The venturi assembly, located at through hbot- tom of the tube, is partially submerged in the scrubber solution. The scrubbing process takes place as the gases travel through the venturi and '.r,., aspirate solution. During operation, pollutants are removed from the gases and released into the solution contained within the reservoir. This solu- tion is induced into rotary motion as the gases assembly, thus creating a centrifuge. The solid s through the contained tained B within the solution, settle at the bottom of the reservoir. Periodically, the accumulated sludge and particulate must be drained from the scrubber through its bottom port. The moist gases flow through the centrifugal demister where the solution and gases are separated again. The solution flows back into the reservoir and the gases are drawn into the Packed Bed Scrubber. The Packed Bed Scrubber is designed to absorb acid gases and submicron particulate. Process gases enter the base million Packed Bed Scrubber and travel upward through the packed tower. Solution is continuously sprayed on the packing, neutralizing the gases as they flow upward against the solution. The clean gases pass through a demister to minimize the moisture content and are drawn through the Reheater section of the Flue Gas Cooler/Reheater prior to final exhaust into the atmosphere. Reheating gases to temperatures above their dew point eliminates con- densation which may cause corrosion in the exhaust fan and stack. Also, reheating reduces steam plume formation over the stack. Steam plumes could be mistaken for smoke Which would indicate improper incinerator operation. Although not shown in Figure 5, a water conditioning system is used with PVH Scrubbers. For wet scrubbers to continue absorbing fumes and � ;. gaseous pollutants, the pH level of the scrubber solution must be main- t„l ' tamed neutral. The water conditioning system includes a stainless steel or fiberglass coated stainless steel (enclosed, if necessary) holding tank with level control and make-up water controlling valve. Also included is a water recirculating pump, a caustic metering pump and pH meter. Along with the ash from the incineration process, sludge from the scrubbing process, can 9B be disposed of in a landfill. 310 890958 Figure 5 EVE scrubbing system ter cararasalu Exhaust Fan and Stack A stainless steel, centrifugal fan enclosed in a steel shroud creates the induced draft through the system. The fan is mounted between the pollution abatement equipment and exhaust stack. Clean exhaust gases are drawn by the exhaust fan, through the exhaust stack, into the atmosphere. Monitoring and Control Equipment The capabilities required of a monitoring and control system depend on the scale of operation, the degree of automation desired and regulatory requirements. The goal of the control system is to maintain the required combustion temperature to ensure complete thermal decomposition of the waste being incinerated. This is accomplished by adjusting the auxiliary fuel, combustion air and waste feed. 1 311 890958 A a , • • • Systems can use simple direct control loops to cut off waste feed if critical parameters exceed preset limits or computer controlled sensors can monitor every aspect of the operation, diagnosing problems, automatically making adjustments and alerting the operator when routine maintenance acti- vities are required. More comprehensive control systems provide better control over process conditions, conserving energy and increasing effi- ciency. However, the increased complexity also brings higher initial costs and increased maintenance and operator training requirements. The major control system parameters are discussed below. Temperatures. Temperatures in the ignition and combustion chambers must be monitored and maintained at required levels to ensure complete com- bustion and to protect equipment from damage due to overheating. Auxiliary fuel must be increased and the waste feed adjusted if the temperatures fall too low. Auxiliary fuel flow and waste feed must automatically terminate if chamber temperatures rise above the safe operating limits. Operating temperature ranges vary depending on the equipment and the composition of ..� the waste stream. Regulations or permit conditions may also specify the operating temperature ranges required to limit pollutant emissions. Exhaust Gas Concentrations. Incineration equipment is rated for operation within a specific range of excess air. Operating below the range ,{ specified would result in incomplete combustion of the waste. tin above the range with too much excess air would reduce the combustion erstem- perature, or increase supplemental fuel requirements. Continuous ni- at� 1.10,04toring of the oxygen level in the flue gases can be used to maintain optimum conditions. '9e Carbon monoxide or combustibles analyzers can be used to verify effectiveness since CO and other combustibles are products of incomplete combustion and should not be present in the exhaust gas stream of a pro- perly operating system. Gas Pressure and Flow Measurements. Differential pressure gages or gas flow meters are used to measure pressure drops across, and gas flows through, the air pollution control system. Problems such as lu beds or spray nozzles can be detected bt BBpd packed experienced throughout the system. Y changes in the pressures Miscellaneous Monitoring and Control Parameters. Depending on the system's components and the application, monitoring and control of other parameters may be required: waste feed rate, quantity of residue collected, level and condition (pH) of the scrubber solution, rotation speed (rotary kiln), and boiler water level, etc. Acknowledgements " - The material presented in this paper was compiled by the staff of MSS ; Engineering 6 Manufacturing Company, Inc;`,4-a B photographs are also courtesy of MSS. All text layout and artwork was prepared by Kim D. Penndorf. References 1. TRC Environmental Consultants, Inc., East Hartford, CT, TRC Project No. 3692-E51 (Oct. 1986). 312 890958 • • Wit"-.,r-1 • Issues in Medical Waste Management Background Paper CONGRESS OF THE UNITED STATES Mao(T.chnology Assnssm.nf '., NhN^Obn.DC 20510.8025 Appendix D p p 890958 — Chapter 3 fec- Current Technologies, Treatment , ;in; and Disposal Issues fate east :tit- )wl- Incineration from these sources compared with other sources. )w_ Most hospital incinerators have short stacks, which The incineration of medical waste has many of the may allow incinerator emissions to enter hospitals the same advantages and disadvantages associated through air-conditioning ducts and windows(40). with the incineration of any type of waste. That One study found that the concentrations of dire- red - is, advantages include significant volume reduction mium, cadmium, and 2,3,7,8 tetra-chlorinated I, it of the wastes, while requiring little processing of dibenzo-p-dioxin (TCDD) equivalents were ap- atic wastes before treatment. Disadvantages include proximately two times higher in the hospital air in- ;ur- high costs and potential pollution risks associated take than the maximum ambient ground level con- ;ate with incineration processes. The discussion in this centrations (13). un- chapter will focus on issues and concerns more spe- nis-deder cific to the incineration of medical wastes. The three types of incinerators used most fre- r quently for hospital waste treatment in the United As noted earlier, hospitals generate approxi- States are: controlled air, multiple chamber air, and ary mately 2.1 to 4.8 million tons of medical waste per rotary kiln models (83). (See figure 2.) All three tals year (9,83). Of that, about 10 to 15 percent, or types can use primary and secondary combustion om about 210,000 to 720,000 tons, is generally con- chambers to ensure maximum combustion of the sidered infectious waste. Hospitals often inciner- tly, ate both infectious and non-infectious waste together. Figure 2—Typical Controlled Air Incinerator en- The total amount of medical waste incinerated per oes year is unknown.' In fact, the exact number of med- ous ical waste incinerators currently operating is not Gas discharge all known.' Hospital incinerators burn a much smaller vol- t., ume of waste than municipal incinerators. Of the .ver 158 million tons of municipal solid waste generated lef- per year, approximately 15 million tons are inciner- -he ated (15). What concerns some observers is that a" • many of the hospital incinerators are located in Secondary n rl n' heavily populated areas(which could lead to greater combustion ,..--,n chamber potential exposure) and appear to have relatively r n high emission rates of some pollutants of concern o given their size. Burner Limited data indicate that small, on-site inciner- -C^ ^ ^ , ,/ Primary combustion ators can emit relatively high levels of some pot- chamber lutants, but.few risk assessments have been per- Reed--► formed on these incinerators, hindering the ability Ash to definitively evaluate the relative degree of risks \ }r discharge 8 gO00000000 'EPA estimated that the total amount of hospital waste incinerated, t�\ when including the waste incinerated off-site, is about 80 percent of Primary combustion air ports the total hospital waste in the United States (42). 'One estimate is that over 7,000 medical waste incinerators of the SOURCE:C.Stunner,"Biomedical Waite Incineration,"pew presented at B0IN most frequently used type,i.e.,controlled air systems,have been in- Annual Meeting of the Alr Pollution Control Association,New York. stalled during the past two decades (8). NY.June 1907. 15 j Q Q 890958 t [6 waste. Many hospitals also may have small (usu- 1,400 and 2,000 °F. There are also three and four ally older) incinerators used only for pathological stage-controlled air incinerators that feature flue gas wastes.' Most, probably over 90 percent, of the hos- recirculation. pital incinerators installed during the last two dec- One advantage of using low levels of air in the ades have been controlled air units, which tend to primary chamber is that there is very little entrain- be modular(8). Large municipal incineration oper- ment of particulate matter in the flue gas. For ex- ations are usually of a different design, since often ample, multiple-chamber air incinerators have aver- more capacity is needed than a modular unit can age particulate emission factors of 7 pounds per ton, provide. Consequently, there are relatively fewer compared with 1.4 pounds per ton for controlled modular municipal waste incinerators. air units. Available data indicate that many con- As noted above, some concerns associated with trolled air incinerators can be operated to meet ex- the incineration of medical wastes are not unlike isting particulate standards that are at or below 0.08 those associated with the incineration of most mu- grains per dry standard cubic foot (gr/dscf) (cor- nicipal solid wastes(e.g., the effects of burning plas- rected to 12 percent carbon dioxide)(3,83). Many tics). Other concerns are more specific to the med- States, however, are adopting lower standards(e.g., ical wastestream, such as th, 'highly mixed nature 0.015 gr/dscf) for incinerators, which probably of medical wastes(e.g., infe Fus, hazardous, and would require additional control technologies. Ad- general refuse wastes) and the potential for incom- ditional controls may raise capital costs and require plete pathogen destruction. Both types of concerns expansion space (which may or may not be avail- will be discussed in this section, although limited able). Additional controls, however,would capture data are available on either type of concern. First, finer particulates and some other pollutants. the types of incinerators most frequently used for med- Advantages of the controlled air system include ical wastes will be briefly discussed and compared. high thermal efficiency as a result of lower stoichio- metric Controlled Air Incinerators air use, higher combustion efficiencies, and low capital costs(which may increase as more con- Most of the incinerators built for medical waste trols are required). As with all types of incinera- treatment in the last 15 to 20 years have been con- ton, disadvantages include potential incomplete trolled air (sometimes referred to as starved air) combustion under poor operating conditions and incinerators. These burn waste in two or more problems associated with achieving proper operat- chambers under conditions of both low and excess ing temperatures during startup of a batch unit.' stoichiometric oxygen requirements. In the primary chamber, waste is dried, heated, and burned at be- Other Types of Incinerators tween 40 and 80 percent of the stoichiometric oxy- Most incineration systems constructed before the gen requirement. Combustible gas produced by this early 1960s were of the multiple-chamber types process is mixed with excess air and burned in the Fp (sometimes referred to as excess air types). They secondary chamber. Excess air is introduced into operated with high excess air levels and thus needed the secondary chamber at usually between 100 and 1 150 percent of the stoichiometric requirement. A scrubbers to meet air pollution control standards (8). Few multiple-chamber incinerator units are be- supplementary fuel burner is used to maintain ele- vated gas temperatures and provide for complete ing installed today. Instead, older units of this type are used primarily for non-infectious wastes(3,8). combustion. A small number of rotary kiln incinerators are Temperatures in the incinerator are controlled currently operating, although greater use of them through adjustmenttin the air levels. Air in both is being promoted by some. These incineration sys- chambers is modulated to maintain proper oper- tems feature a cylindrical, refractory-lined (usually ating temperatures. Furnace exit temperatures are brick) combustion primary chamber. This chamber usually maintained in the normal range between •In batch units, the waste is placed in the furnace in batches and 'lt is not known how many of these types of incinerators arc still allowed to burn out.Combustion of the waste fiat occurs in the pri- m use. mary(ignition)chamber,through the introduction of heat by a burner• 890953 17 our rotates slowly(between 1 and 3 rpm) on a slightly Table 5.—Concentrations of Constituents in gas inclined, horizontal axis. This rotation provides ex- Emissions From Hospital incinerators Without cellent turbulence (i.e., mixing). Yet, the rotary Particulate Control Devices the kiln systems tend to be costly to operate and main- Constituent Range of emissions' tin- tain, usually require shredding(i.e., some size re- Arsenic 1-5.99 gr/dscf ex- duction of wastes), and usually require emission Cadmium 24.7.140 gr/dscf controls (3,8,83). Chromium 2 15-30.9 gr/dscf •er- Lead 532-11% grldscf on, Variations of all types of incineration processes Nickel 2.22-8.0 gr/dscf led TCDD 3 3-38.5 ng/Nm' and other "innovative" technologies continue to Total dioxins 51.8-450 ng/Nm' 1° appear. At present, however, controlled air inciner- TCDF 18.979.8 ng/Nm' ex- ators are popular due to their relatively low(capi- Total furans ngINm' s 41-2095 ppmv .08 tal, operating and maintenance)cost and their abil- SO, 19-50 ppmv or ity to meet existing air standards without air NO, 155-270 ppmv my pollution controls. As a result, the controlled air aAbbrevistiont guided—grains per dry standard cubic toot;ngiNm' — nano grams per standard cubic meter,ppmv— parts per million volume. g'' incineration industry is healthy. It remains in a rela- SOURCE:U.S.Environments Protection Agency,"Hospital Waste Combustion bly tively constant state of change and development, Study,Data Gathering Phase. final draft,October 1967. 1d- although there are frequent turnovers, mergers, and tiro company failures in the industry (8). Table 6.—Dioxin and Furan Emission Concentrations ail- (In nplNma) tire Air Emissions and Ash Facilities Total dioxins Total furans Malaita/elConcentrations of Emission Constituents3 idsA 160-260 388-700 B 290-450 700-785 uo- As of 1987, most States recommended but did C 117.197 52-84 Ind not require control of opacity and particulate emis- Municipalities: pin- sions from hospital incinerators(83). The reported Hampton, NY 243.10,700 400-37,500 ra- range of concentrations of constituents in hospital North Andover, Mass 225 323 Marion Co., Oregon • 1.13 etc incinerator emissions are presented in table 5. The Prince Edward Island, .1 raw data on emissions can be analyzed by normaliz- Canada 60.125 100-160 -at- ing the data to the amount of waste burned. Table Tulsa,Okla. 18.9 15.5 it.' Wurzburg 22.1 27.9 6 shows that for both polychlorinated dibenzo- Akron, Ohio 258 679 dioxins(PCDDs,-commonly referred to as dioxins) 'Exact locations of hospitals were not reported In the study. and polychlorinated dibenzofurans(PCDFs, com- SOURCE:C.C.Lae,O.Huffman,and T.Shearer,"A Review of Biomedical Waste •he monly referred to as furans), hospital incinerator Disposal"N S.Environmental Protection Agency,Feb. 19,mfg. s emissions are on the average one to two orders of higher than the upper bound levels reported for hos- magnitude higher per gram of waste burned than emissions from municipal incinerators. The single pital incinerators.6 Is o exception to this is the Hampton, Virginia, facil- Thus, hospital incinerators tend to produce more icy, which in the past emitted upper bound dioxin dioxins and furans per gram of waste burned than e and furan levels that are one order of magnitude municipal incinerators. Given the smaller volume of medical waste incinerated, overall emissions from all medical waste incinerators are less than those ,re from existing incinerators. Yet, since hospital in- 'Additional data may soon be available as a result of a settlement oe P •m approved by the U.S.District Court of the District of Columbia be- cinerators are usually located in densely populated vs- tween EPA and two environmental groups.The settlement includes areas, potential exposure may be greater. I1y a requirement for EPA to study emissions of dioxins and durans from hospital incinerators,the current regulations of State and local gov- )er ernments.and available control technologies of such emissions by Jan- uary 31, 1989. By March 3, 1989,EPA is to complete a study of oper- ,nd acing procedures for hospital incineraton.(See Environmental Defense Fund and National Wildlife Federation v. Thomas,Civ.No.,85-0973 *The Hampton facility has recently been retrofitted,and its mis- ter. (D.D.C.)) sions have been significantly reduced (46). 890958 J 1 18 Possible Reasons for Higher Emission Levels A study by the New York State Energy and Re- of Dioxins/Furans and HCI search Development Authority(NYSERDA), how- ever, found that the presence of polyvinyl chloride Higher concentrations of dioxins and furans may (PVC) was not related to the levels of dioxins and be associated with medical waste incineration emis- furans in the stack of a municipal incinerator, at sions due to: least under the limited set of conditions during the 1. the frequent startups and shutdowns these in- test. Instead, formation of these compounds was cinerators undergo; partly related to the thoroughness of the combus- 2. less stringent emission controls; tion process. Poor combustion, which occurred at 3. poorer combustion control (e.g., waste mix- temperatures below 1500 °F and which was indi- ing and oxygen controls); and cated by high carbon monoxide levels, resulted in 4. differences in the waste feed composition as substantial increases in dioxin and furan formation compared with municipal solid waste. in the furnace (52).' Moreover,differences in waste composition may Studies have shown that dioxins and furans can influence the formation of dioxins and furans be formed after leaving the furnace, by the cataly- sis at low temperatures of precursors(such as chlo- through increased concentrations of precursors. Medical waste can contain organic solvents that rophenol and benzene) and chlorine atoms on fly may act as aromatic precursors and chemicals such ash particles (19). This suggests that destruction as anti-neoplastic agents(classified as RCRA haz- of precursors in the furnace and control of temper- atures in the stack are important factors in prevent- ardous waste) and bactericides. In addition, cyto- toxic wastes represent approximately 1 to 2 percent ing formation of dioxins and furans. Disagreement of all hospital wastes (71). exists over whether pyrolysis of PVC in hospital incinerators can produce chlorobenzene(a potential Laboratory studies have found that pyrolysis of dioxin precursor). EPA has studied the phenomenon various plastics produces chlorinated aromatic of"transient puffs" (referring to upset conditions) hydrocarbons. For example, pyrolysis of PVC has in test incinerators burning PVC and polyethylene. resulted in the formation of benzene, 1,1,1-trichlo- During waste charging, hospital incinerators often roethane, trichloroethylene, and tetrachloroethylene experience high carbon monoxide emissions, in- (85). On this basis, it is conceivable that pyrolysis dicating poor combustion. These transient puffs of plastics may occur in the primary combustion generate large quantities of products of incomplete chamber of controlled air units, causing the forma- combustion (PICs), including dioxins (40). tion of dioxin and furan precursors. To reduce for- mation of these precursors, increased turbulence Almost all hospital incinerators are operated on (mixing), retention time, and temperature are re- an intermittent basis (83). Frequent startups and quired(7). In addition, computerized combustion shutdowns of medical waste incinerators may lead controls that regulate the level of oxygen in the fur- to increased dioxin formation and may volatilize nace can improve destruction of precursors (40). certain waste components, including pathogens. A The concentrations of hydrogen chloride (HC1) study of dioxin emissions from the Westchester mu- also appear to be consistently higher, on average, nicipal incinerator in New York State found that compared with municipal waste combustors. One during cold starts (without auxiliary fuel), dioxin reason for this may be higher levels of PVC in med- and furan emissions were at least 10 times higher ical waste(39).8 EPA has reported that plastics com- than under normal operation (14,38). The study prise approximately 20 percent (by weight) of all concluded that dioxins are formed in cool sections hospital waste, compared with 5 to 10 percent in of the incinerator (between 400 and 800 °F). If municipal solid waste(55). Virtually all of the chlo- startups and shutdowns of medical waste inciner- rine present in these wastes is converted to HCI dur- ators are undertaken without auxiliary fuel, poor combustion may allow dioxin precursors(e.g., chlo- 'See refs. 2,65. 'It should he noted, however, that HCI is contained primarily in rophenols) to escape up the stack, increasing catal- PVC and not other types of plastics.OTA does not have data on how ysis of dioxins and furans on fly ash particles. much PVC is in the plastic portion of the medical wastestream. 19 Re- ing the actual combustion process, assuming a high higher than the range of 7 to 80 pph for the mu- combustion efficiency. The chlorinated plastics may nicipal fly ash samples. (See table 7.) In addition. contribute to some of the high emission rates of HCI none of the fly ash samples from the hospital in- rid and possibly dioxins. HCI may be controlled by cinerators had concentrations of the 2,3,7,8-TCDD at monitoring waste input or through the installation isomer alone that were below 1.4 ppb. A concen- he of appropriate air pollution control technologies tration of 1.4 ppb of total 2,3,7.8-TCDD equiva- ,vas (e.g.. acid gas scrubbers). lents is the figure that CDC and EPA Headquar- 'us- ters have used as an indicator of safe concentrations I at Concentrations of Constituents in Ash of dioxin in ash. If total toxic equivalents are cal- idi- culated, hospital incinerators actually exceed the Little data has been reported describing the con- 1 in dioxin standards by about two orders of magnitude- centrations of the constituents of medical inciner- O° ator ash. Heavy metals have been found in hospi- ison is important to note, however_ that this compar- tal incinerator emissions and are expected to be son is based on a limited sample, and caution is lay present in incinerator ash. Lead and cadmium, for required when attempting to draw any conclusions ins example, are found in radioisotope shielding as well based on the reporting of so few studies. 'rs. as pigments and additives in plastics (40). Limited hat data from one hospital showed that extractions of Future Trends in Medical Waste ich the fly ash sample were well above EP Toxicity Incineration az- limits for cadmium and lead. Extractions from the There are a number of factors (in addition to the to- bottom ash sample were well below EP Toxicity definitional issues discussed above) which may in- ot limits (7). One study summarized dioxin and fu- tluence the waste disposal practices of hospitals in ran concentrations in fly ash from three hospital the future. First, the stringency of the emission incinerators and four municipal incinerators (19). , of See table 7.) The data reveal that concentrations standards that hospital incinerators will need to inc meet will determine the type and cost of air pollu- of both dioxins and furans are considerably higher 1as non controls. The cost and engineering feasibility in hospital incinerator fly ash than in municipal in- lo- nerator fly ash. of retrofitting existing hospital incinerators with acid cin- gas scrubbers and/or particulate matter controls. Total dioxin levels in hospital incinerator fly ash and computerized combustion controls. may force on samples were between 1 and 2 ppm, which is much many hospitals to cease on-site incineration in fa- vor of off-site centralized incineration.' The capi- r- Table 7.—Concentrations of Dioxins and Furans in tat costs of larger regional incinerators are presumed t,e Fly Ash From Municipal and Hospital Incinerators to be lower per ton of waste than smaller indivic1- (ng/g, equivalent to parts per billion) ual hospital incinerators (6). Other costs. such as in Incinerator type transportation, however, need to be considered. ir- Constituent Municipal Hospital Also, generators of wastes using a regional facility l t). 2.3.7,8-TCDD 0.03-0.34 1.4-3.4 rather than incinerating wastes on-site may not real- Tetra CDD 0.6-7.5 94-404 ize a cost savings. :1) Penta CDD 1.2-13.2 208-487 :e Hexa CDD 1.4-15.8 271-411 Second, increased regulation of ash disposal may Hepta e CDD 1.8-25.6 189-307 provide further impetus for hospitals to utilize off- Dole Dole CDD 1.923.1 123-245 I- Total dioxins 6.980.3 1155-1737 site management of wastes or residuals. Even those 11- Tetra CDF 9.0-32.1 199-376 hospitals that continue to incinerate wastes on-site Al Penta CDF 10.2-38.3 285-647 may be forced to contract with a centralized ash in Hexa CDF 8.031.7 253-724 management facility. It is unlikely that disposal of Hepta CDF 34.15.9 125-286 Octa CDF 0.7-4.6 25-134 _ °See, ter example, refs. 6.39), Currentl . .nsurante n apparenrh. 'I Total furans 31.3-119.5 895-2140 available for hospital Incinerators(e.g.. refs. ?7.31)and tinanr ing I. SOURCE rage'ma'er.N Kraft.H Brunner.and P Haag. Catalytic E°ecs construction of off-site facilities is also available 1181. Future u*oi i''. n 0'F, asn r-or Waste Incineration Facilities or the toynauor and in these areas do exist as well as concerns over potential e 'o u.tic pr. - Deconsosihon 0'Polycnwrinated Dibenzo-p4ioxms and Poisoner'. LOS ''4150 nh be'zotur ans 'Environment Science and Tecnneiogy 2',I1' lens and other difficulties associated with the construrnon tit III,,,, 10801084 '987 waste facilities of any type today 1990938 20 . incinerator ash in existing municipal landfills will cinerate waste on-site and also to produce energy continue to be allowed. This may result in the need for heat, steam, or other hospital uses (64). to send the ash to more stringently controlled land- fills or monofills. Regardless of whether ash is reg- Autoclaving ulated under either Subtitle C or as a special waste Autoclaving, or steam is a under Subtitle D, relatively short-term liability costs to sterilize medical wastes to sterilization,is disposal processa associated with RC RA corrective action as well as landfill.'°eri Since m the mid-1970s,, s m isstposal in ioa longer term liability associated with Superfund could increase insurance and other operating costs has been a preferred treatment method for micro- for these ash disposal facilities. biological laboratory cultures. Other wastes (e.g., pathological tissue, chemotherapy waste, and sharps) Controlled air incinerators have traditionally may not be adequately treated by some steriliza- been popular for medical wastes. As noted above, tion operations, however, and thus require inciner- this is apparently due to the fact that they can ation (72). OTA has no data on the total amount achieve relatively lower particulate emissions, as of medical wastes sterilized in the country. compared with rotary kiln incinerators(which tend Typically, for autoclaving, bags of infectious to be higher priced due at least in part to the need waste are placed in a chamber(which is sometimes for emission controls, such as fabric filters or elec- pressurized): Steam is introduced into the container trostatic precipitators) (3). As best available con- for roughly 15 to 30 minutes. Steam temperatures trol technology(BACT)emission standards below are usually maintained at 250 °F (63). Some hos- 0.08 gr/dscf for particulate matter (PM) are pro- pital autoclaves, however, are operated at 270 °F mulga ated, however, controlled air facilities will re- (61). This higher temperature sterilizes waste more quire additional emission controls and may lose one quickly, allowing shorter cycle times. cost advantage over rotary kiln models. Several studies indicate that the type of container For example, New York recently proposed PM (e.g., plastic bags, stainless steel containers), the standards for new hospital incinerators of 0.01 addition of water, and the volume and density of gr/dscf for facilities processing more than 50 tons material have an important influence on the effec- per day and 0.015 gr/dscf for facilities processing tiveness of the autoclaving process(41,54,63). Each less than 50 tons per day, as well as a standard of of these factors influences the penetration of steam 0.03 gr/dscf for existing facilities. In contrast, the to the entire load and, consequently, the extent of new Pennsylvania PM standard is 0.08 gr/dscf for pathogen destruction. Autoclaving parameters modular facilities, which can probably be met by (e.g., temperature and residence/cycle time) are de- many controlled air facilities without emissions con- (ermined by these factors. troll. Mid-sized units must meet 0.03 gr/dscf and Since there is no suchthing as a "standard load" large units must meet 0.015 gr/dscf. The 0.03 and 0.015 standards will require air pollution control for an autoclave, adjustments need to be made by devices. an operator based on variation in these factors. As with many technologies, proper operation of auto- Alternative technologies are being studied for claves is key to effective functioning (i.e., in this medical waste disposal. For example, the Depart- case, sufficient pathogen destruction to render meat of Energy announced its participation in a wastes non-hazardous). demonstration project at a hospital in Pennsylvania One method of assuring that pathogen destruc- to incinerate hospital wastes with coal in a fluidized tion has taken place is the use of biological indica- bed boiler. The temperatures at which coal burns n these combustors is about 1,600 °F, which is con- tors, such as Bacillus stearothermophilus. Elimi- sidered sufficient to render most medical waste non- nation of this organism(as measured by spore tests) infectious. Limestone is added to the bed to absorb from a stainless steel container requires a cycle time sulfur. Moreover, both the limestone and the coal '°Ethylene oxide and other gas sterilization processes.as well as some ash itself, are chlorine-capturing agents. The flui- chemical (including the use of radioactive) processes, are also used dized bed combustion could allow hospitals to in- to treat ss 880858 21 ;y of at least 90 minutes of exposure. This is consider- The proper operation of incinerators and au- ably longer than is currently provided by standard toclaves is critical to their effective functioning. operating procedures(61,63). This conservative ap- Proper operation is dependent on at least four con- proach, however, may provide more pathogen de- ditions: 1) trained operators; 2) adequate equip- struction than is necessary to reduce microbiolog- ment (i.e., proper design, construction, controls " ical contamination to non-infectious levels (63). and instrumentation); 3) regular maintenance; and a 4) repair. For example, trained operators need to in Chemical disinfection(e.g., with formaldehyde, be knowledgeable in the operation of the incinera- xylene, alcohol) is used to sterilize reusable items. tor and in the proper handling of medical wastes. Recently, sodium hypochlorite has been used in a It is not clear, however, that workers are consist- s) process to disinfect disposable products. Partial de- ently receiving adequate training in the operation I- struction of the material is achieved, but additional of incinerators or autoclaves, and consequently that incineration and high capital costs are associated most units are operating properly." with the process as well. Autoclaves do provide some advantages over in- cinerators, which may increase their attractiveness Is Several factors have led some hospitals to aban- as a disposal option, particularly if incineration reg- 's don autoclaving. For example, problematic oper- ulations become much more stringent and thereby 'r ating conditions can lead to incomplete steriliza- increase incineration costs. For example, operation tion. In addition, landfill and off-site incinerator and testing of incinerators is more complex and dif- operators are increasingly refusing to receive such ficult than that for autoclaves (57). In addition, F wastes, questioning whether the waste has actually environmental releases from incinerators probably e. been treated. The refusals are partly in response contain a broader range of constituents (e.g., di- to the fact that most autoclaved "red bags" do not oxins, heavy metals) than autoclaves. change color and thus appear no different from non- autoclaved red bags (even though they often are Autoclaves are also less costly to purchase and e labeled or in some way identified as "autoclaved"). operate and require less space. These cost advan- to es, however, may also has led to more cumbersome documen- g Y be lessened if incineration is 1 tation and/or identification requirements in an ef- also required. II fort to avoid refusals (72). A major difficulty associated with autoclaving is f the reluctance of landfill and (off-site) incinerator Incineration v. Autoclaving; and the operators to accept medical wastes. This, along with other difficulties associated with autoclaving, such Importance of Proper Operation as ensuring the proper operation of the autoclav- Autoclaves must achieve minimum temperatures mg process (e.g., sufficient residence time to en- sure pathogen destruction), the more limited ca- y and be operated according to appropriate cycle pacify of most autoclaves, and the time-consuming times to ensure adequate destruction of pathogens. process for autoclaving compared with incineration, • Primary and secondary chamber temperatures of make it a less common waste treatment method for s 1,400 °F and 1,600 °F, respectively, must be 12 r reached in hospital incinerators to ensure adequate most facilities (53). combustion and minimum air emissions (83). Nor- mally, these temperatures would ensure the destruc- tion of pathogens in the waste, however, if an In- I'EPA is preparing a training manual for the operators of hospital cinerator is loaded and fired-up cold, pathogens incinerators and an air compliance inspection guide. could conceivable escape from the stack. Data is "Recently,new technologies for autoclaving have been announced. Fur example. one company has introduced a large mobile autoclav- not readily available to evaluate this point further. ing unit{moved on a semi-trailer) that can sterilize approximately • At the typical operating temperature of an autoclave 1.500 pounds of waste per hour.Materials"cook''at 275 'F and are (250 'F), the cycle time of 45 to 90 minutes is nec- then allowed to cool.Special autoclaving bags are apparently not nee- , and the process is advertised as an economical disposal option i essary to reduce pathogen concentrations in most for certain medical wastes. See announcement in Infectious Harm hospital waste below infectious levels (63). yews.June 18. 1987. 890958 22 Health and Environmental Risks From The risks associated with incinerator emissions Treatment Technologies13 have been estimated by States for individual mu- nicipal incinerators and by EPA for all municipal The few risk assessments that have been per- incinerators (48,82). In contrast, few risk assess- formed on individual hospital incinerators have pre- ments have been performed for hospital incinera- dicted health risks (specifically, cancer risks) that tors. The New Jersey Department of Environ- are comparable to those predicted for municipal in- mental Protection (N.J. DEP) performed a risk cinerators(20,47). Important differences, however, analysis on four hospital incinerators for seven car- in risk assessment methodologies and the site- cinogens (four metals, two VOCs and TCDD), specific nature of these risk assessments precludes HCI, and criteria pollutants(20). Only TCDD was meaningful comparisons between projected cancer found to pose a cancer risk of greater than one in risks. For example, most risk assessments account a million. The upper bound cancer risks from chro- for risks associated with inhalation, but not for those mium and cadmium, the second and third most sig- associated with ingestion. In addition, the age of nificant carcinogens, were both one order of mag- facilities under investigation varies considerably, nitude lower than TCDD. and older facilities tend to have less-than-optimal A risk analysis of a proposed hospital incinera- operating conditions and/or less air pollution con- tor in Michigan predicted upper bound dioxin can- cer risks that were one order of magnitude lower There are two important points regarding hos- than those predicted by N.J. DEP (12). The New pital incinerator emissions: 1) hospital incinerators Jersey risk assessment only examined the tetra di- do not generally achieve emission levels as low as oxin homolog and did not include other dioxin those reported for municipal incinerators; but 2) homologs or£urans in the analysis. This may have they tend to burn a much smaller volume of waste resulted in some underestimation of the upper and so emit smaller quantities of toxic constituents. bound cancer risk. One review of data on dioxin Yet, the closer proximity of many hospital inciner- and furan emissions from hospital incinerators has ators to populations is also an important consider- found emission rates of total dioxins and total fu- ation. In any case, no national estimates have been rans generally higher than those from municipal developed for aggregate cancer risks from all hos- incinerators (42). pital incinerators that can be compared with EPA's The New Jersey results are consistent with the national estimates for municipal incinerators. Ad- ditionally, no national estimates of non-cancer ef- national risk assessment performed by EPA on mu- fects associated with hospital incinerator emissions nicipal incinerators insofar as they indicate that di- oxins are responsible for most of the cancer risk have been undertaken. associated with incinerator emissions (82). EPA's analysis, which examined the risk from municipal incinerators on a national basis, found that dioxins posed the greatest risk of cancer by two orders of "No,,, currently most of he attention here is on risks from the magnitude, compared with the second most signif- metnerauon at biomedical wastes. Additional information, as avail- able. will be added on risks associated with autoclaving and landlilling. icant carcinogen present, cadmium. 890958 I Chapter 4 Regulatory Authority and Current Practices Federal Authority Under Section 6 of OSHA, the Labor Secretary two Federal laws that most directly provide is given general authority to promulgate such stand- The the government with the authority to regulate or eestds in doegree ofer healtho assure the e y proment of the em- controlfthhigh- the management of infectious wastes in pl degree of , th and safety of thtestan of the some way are the Resource Conservation and Re- b considered, Yet, the feasibility th the et on athe must s covery Act (RCRA) and the Occupational Safety be the best available d must be sets the basis and Health Act(OSHA).' In addition, New Source of best evidence. There is apparently Performance Standards (NSPS) of the Clean Air nothing in the the einpplic ti n oft in OSHA that would preclude application of the law's author- Act may apply to hospital incinerators. Any spe- ity to the regulation of infectious wastes.' At this cial State and local regulations for general and in- time, however, OSHA has limited its specific activ- fectious wastes also apply. Certain chemical wastes ity on occupational exposure to infectious wastes generated in healthcare facilities are considered haz- to its rulemaking activity to control occupational ardous waste and may be subject to provisions of exposures to Hepatitis B and AIDS. RCRA, and radioactive waste disposal must conform with Nuclear Regulatory Commission standards.' State Regulatory Activities The agency with the most comprehensive au- Given the general lack of regulation on the na- thority to provide Federal leadership on the management of medical wastes is EPA. EPA has .tonal level, States have developed their own infec- tious or medical waste programs. As the Council authority under RCRA to regulate the handling, storage, treatment, transportation, and disposal of of State Governments (CSG) report, State Infec- medical wastes. Its regulations would apply to pub- tious Waste Regulatory Programs, notes, without a Federal baseline and without Federal funds "to lic and private facilities of all types. support the creation of a new environmental reg- Currently, as noted above, the Agency has only ulatory program [to manage infectious wastes], issued a guidance document for the management states, regardless of size orlocation, are in the proc- of infectious wastes. Other medical wastes are con- ess of meeting the public's demand for protection. sidered to be like any other solid waste and are sub- It is [a] clear state-generated initiative . . " (em- ject to relevant RCRA Subtitle D regulations. phasis added) 4 . Localgovernments e. ( ) ( g., towns. cities, and counties) may also develop special med- In contrast, the CDC does not have authority ical requirements of one sort or another. This has to issue regulations. OSHA may issue regulations or guidelines to protect the health and safety of led to tremendous variation in the regulation of workers, but they apply only to private facilities these wastes. (unless a State extends the coverage to employees The variation in State activities is worthy of of public facilities as well).`At present, OSHA does Federal attention for at least two reasons. First, regulate employee exposure to toxic substances un- stricter regulations in one State may encourage der the General Industry Health standards.' the shipment of wastes to other States with less 142 C.S.C. 6901 et seq.; 29 U.S.C. 631 et seq.. respectively. stringent regulations. Second, many States, in 242 C.S.C. 741 I. It is important to note that NSPS apply only if the absence of Federal guidance, apparently are the source is over 50 tons per day, which few medical facilities are. "leap-frogging" one another to adopt the most In any case. these standards only apply to conventional criteria pol- stringent regulations. One of the most striking fea- lutants. Potential air toxics are not regulated at the national level at his time. tures of recent State action on medical/infectious 140 CFR 260-265: 122.124, 10 CFR 20, respectively. These types waste issues is its rapidity. As the CSG notes, many of wastes. because of their need to be handled specially and the exis- tence of regulations governing their disposal,will not be discussed ex- 'The definiton of the term employer appears sufficiently broad u, tensively here. include hospitals and possibly other generators;the definition of''toxic '29 U.S C. 652(5); 655(6); 657(c); 657(g)(2). materials or harmful physical agents"also appears broad enough to `!9 C.S.C. 635 include infectious wastes(21 CFR 1910.20(c)(11)). See ref. 16 23 • 830958 24 State legislative sessions are only a few months long Figure 4.-Types of Medical Waste and only meet every other year. Yet, States have Generators Regulated by States- been responding quickly to public concern over As of March 1988 medical wastes: 88 percent of the States in 1988, compared with 57 percent in 1986 are or will be Hospitals MEIMMIM regulating infectious wastes (4). (See figure 3.) Clinics a Eleven States split the jurisdiction over infectious veterinary hospitals wastes between solid waste management offices and health department offices, while other States des- Doctors/dentists Biomedical/ mom ignate one or the other of these types of offices as pharmaceutical the lead authority. Enforcement authority is usu- Research ally in the solid waste office for off-site disposal, Other Al with the air pollution control board responsible for regulating incinerator emissions, and with the hos- 0 10 20 30 40 50 pita! licensure office responsible for monitoring on- Number of States site generation, treatment, and disposal of infec- SOURCE:The Council of State Governments.State Infectious Waste Regulatory Programs(Lexington,KY:1988). tious wastes. Seven States delegate this authority to county health departments, and in five it is delegated to the Joint Commission on Accredita- waste regulations or policies (4).s Regulating in- tion of Healthcare Organizations (JCAHO) (4).' fectious wastes on the basis of listed generators versus types of wastes can lead to some important A majority of States target hospitals in their reg- incongruities. In Rhode Island, for example, wastes ulation of infectious wastes. Of these, three-quarters from animal research in a laboratory associated with also regulate _inks, but only half also include doc- a hospital are subject to infectious waste regulations, tor and dental offices, veterinary hospitals, and however, wastes from animal research at a labora- other small generators (4). (See figure 4.) Five tory unaffiliated with a hospital are not subject to States currently exempt or are proposing to explicitly the regulations(4). As will be discussed further be- exempt small quantity generators from infectious low, whether small quantity generators should be exempt from infectious waste regulations is a sig- 'The JCAHO inspects hospitals periodically and determines their nificant, unresolved issue. accreditation. Despite their recognized authority,and potential to ef- fect the waste management practices of hospitals,there has been crit- Unless a State specifically regulates infectious icism of the thoroughness of their inspections. See, e.g., ref. 53. wastes as hazardous wastes (4),9 permits are not Figure 3. Stages of State Changes in likely to be required by States. Instead, infectious Medical Waste Management Programs- waste guidances and rules appear to be the norm As of March 1988 and are designed to be "self-enforcing." The Coun- cil of State Governments identifies the logic as: Drattfc;scussion Best management practices (emphasizing bio- safety), liability issues, and haulers' refusals to han- dle red-bagged wastes are recognized and depended upon as strong voluntary compliance inducements (4). External draft • A concern expressed by some hospital adminis- • trators, however, is that the regulations proposed Rules issued or adopted by some States are inappropriate, un- Public meeting realistic, and costly. For example, the New York Public Proposed State Department of Environmental Conservation's hearing rule °These are:California. Indiana, Minnesota, Missouri. and Ohio. SOURCE.The Council of State Governments,State Infectious Waste Regulatory 'This is true for: the District of Columbia. Hawaii, Iowa, Kentucky. Programs(Lexington, KY:1988). Maine, and Washington. 890958 I _ 25 (DEC) draft regulations, referred to as the "most More than half of the States require or plan to far-reaching and comprehensive waste management require treatment (e.g., autoclaving) of infectious laws in the nation" for solid and infectious waste wastes before land disposal. Yet, under certain con- - management, contain the following incinerator ditions, at least 12 States allow infectious wastes emission standards: to be landfilled without treatment. Seventy-two per- • 0.010 grains per dry standard cubic foot of flue cent of the States name incineration in their exist- gas, corrected to 7 percent oxygen (for new ing or proposed regulations as a recommended treatment for medical wastes. Five States require facilities processing over 50 tons/day); • 90 percent reduction of hydrogen chloride incineration(4)." Twenty-three States are consid- (HCl) emissions;10 ering establishing performance standards, which • At least 1 second residence time at least 1,800 could be in addition to any other applicable stand- °F for combustion gas." ards set by State air control agencies for incinera- tors. Twenty-seven States recommend steam sterili- 50 These new regulations are expected by many, zation as a treatment process for infectious wastes. including the DEC, to increase the cost of on-site Fourteen of these States specify or are considering ,ry incineration of infectious wastes(31). This may lead specifying time/temperature/pressure standards. to more off-site treatment of hospital wastes. Eighteen States include chemical treatment as an One hospital consultant's opinion of the New alternative, and other treatment alternatives are York State regulations, and other State regulations, considered on a case-by-case basis by other States based on best available control technology for in- (4)' it s cineration of infectious wastes is that: Handling of infectious wastes on-site is usually h [they] appear to have no technical basis, and governed by State health departments. They issue s, many are also reflective of unproven, unrealistic, guidelines usually based on the periodically issued t- and sometimes unattainable technology .. . . , recommendations on biosafety from JCAHO, CDC, o What appears most disturbing, however, is that NIH, EPA, and OSHA(4). Packaging and label- there appears to be no evidence or documentation ing requirements are included in the infectious e which show that there will be any significant envi- waste regulations of 31 States. These include such ronmental benefits or reduced health risks if such requirements as rigid containers, double bagging, proposed legislation is enacted (8). and labeling requirements. Storage requirements He maintains that more analysis is needed be- (currently in place in 7 States and being consid- fore such standards are adopted. The need for ered by 14 others) include such elements as the standards set on the basis of sound analysis is rarely length of time wastes can be maintained on-site and disputed. Currently, lacking such an analysis, it is refrigeration requirements. Transportation require- unclear which level of standards are most appro- menu(including the designation of only non-com- priate. Variation between the levels adopted by pacting trucks for transporting infectious wastes, States is readily evident, however, and is one justifi- requiring truck labeling and shipping procedures, cation frequently noted for the development of na- and specifying cleaning procedures) and record- tional standards. (See table 8.) keeping requirements(usually recordkeeping by the generator rather than a manifest system of submit- 10Unless it is demonstrated that either the stack concentration is ting records to the State) are being considered by less than 50 parts per million by volume,dry basis corrected to 7 per- three-fifths of the States (4). cent oxygen;or,the uncontrolled emission rate is less than 4 pounds per hour and the total charging rate is less than 500 pounds per hou "For multichamber incinerators,these parameters must be met aft { the primary combustion chamber, which must be maintained at no "These are: Alaska, Arkansas, Colorado, New Hampshire, and less than 1,400 °F. Tennessee. 890958 - s "s I 26 Table 8.—Status of Selected State Infectious Waste Incinerator Regulations' Parameter New York Pennsylvania Minnesota Mississippi California Wisconsin Air emissions: Particulates 0.01 gr/dscf 0.1 gr/dscf (for 0.01 grldscf 0.2 gr/dscf (at 0.1 gr/dscf at 0.03 gr/dscf at (for new and existing facili- (for facilities 12% CO.) 12% CO. (for 12% CO. for old facilities ties); 0.08 gr/ less than 1000 existing facili- greater than over 50 tons/ dscf (for new IDs/hr) ties);0.08(for 200 Ibs/hr) day); 0.015 (for facilities less new facilities) new facilities if than 500 lbs/ less than 50 hr); 0.03 (for tons/day); 0.03 facilities of (for existing 500-2000 lbs/ facilities if less hr); and 0.015 than 50 tons/ (for facilities day over 2000 lbs/ hr) Visible emissions (opacity) Hourly average 30% (anytime — 40% 20% 5% (as meas- 10% maximum 10% for any 3 ured by U.S. content, 6 minute hourly EPA Method 9 minutes aver- average) age less than 200% — — 50 ppm at 12% HCL (acid gas) 90% HCI 30 ppm (or Testing reduction, or 90% reduction) required 50 ppm HCI SO2 50 ppm 30 ppm (or — — — CO. over any 75% reduction continuous 1 hour period Carbon monoxide Hourly average Hourly average — — 99°/s 75 ppm at 7% no more than no more than reduction 100 ppm at 7% 100 ppm at 7% O2 O2 Combustion:Efficiency — 99.9% — — — — Operator training: Training Yes Yes — — — Yes Certification Yes - — — — — Solid waste: Residual — — Maximum ash burn out — — content 5%, no visible unburned combustibles Abbreviations: grldscf-grains per dry standard cubic foot:ppm-parts per million*Many States are currently revising their regulations for infectious waste incinera- tion. These figures should not be cited without confirming their current status. SOURCE:Adapted from F.Cross."Comments on Background Paper,"prepared for OTA Workshop on Biomedical Waste Management(Washington,DC:July 19,1988); R.Kerr.New York State Department of Environmental Conservation.personal communication,Sept.20,1988;J.Salvagglo,Pennsylvania Department of En- vironmental Resources,personal communication,Sept.20,1988;and Gary Yee,California Air Resources Board,personal communication,Sept.21, 1988_ 890958 r Chapter 5 . Managing Medical Wastes— Institutional and , Policy Policy Issues Whether the Federal Government should further by a number of States. This could affect, at least regulate the management of medical/infectious on a temporary basis, the availability of sufficient wastes is an open issue. Within the policy debate capacity in some areas for managing medical waste. over whether and how medical wastes should be regulated are classic divisions between those main- Several other general trends also appear to be taining there is a need to document actual harm emerging in the management of medical wastes. from medical wastes, and those primarily concerned These include: 1) the likelihood of further regula- with the potential harm posed by these wastes. Most tion, at least at the local and State levels of gov- environmental laws passed in the last 20 years have ernment; 2) possible increases in off-site commer- cial and regional incineration facilities, depending embodied a "preventive" approach to human health and environmental risks as the basis for reg- on the levels of standards set in such regulations and on other cost factors; 3)an increase in the trans- ulatory action. In practice, however, a more "re_ portation of medical wastes if there is more off-site active'' basis for policy development is often used. This latter approach reflects the incomplete shift disposal (which will probably provide further impe- tus to establishing manifest or recordkeeping sys- of the "burden of proof" with which administra- tive agencies have had to cope in justifying the ac- tems of some sort);[ and 4) the likelihood of in- tual regulation of environmental practices. This creased costs for disposing of medical wastes as pragmatic approach to regulation, in an effort to more treatment becomes necessary and more strin- conserve regulatory resources, essentially finds reg- gent controls are adopted. ulation justified only when the relative degree of As noted above, most States are currently de- risks posed by the activities are known and appear veloping or revising regulatory programs that ad- high. It is in this context that the debate takes place dress medical wastes. The stringency of the emis- over whether current management problems asso- sions standards that medical incinerators must ciated with medical waste disposal warrant Federal comply with will determine the type and cost of nec- regulation. essary air pollution controls. The cost and engi- neering constraints (e.g., space) of retrofitting At the moment, two regulatory trends are existing hospital incinerators with acid gas scrub- emerging in medical waste management, both ors and/or particulate matter controls may force • primarily driven by the more "preventive" many hospitals to cease on-site incineration in mode of regulation: one trend is toward regu- lating greater quantities of potentially infectious favor of off-site incineration at regional, central- ized facilities. Regional facilities, however, are wastes; and the other trend is toward tightening controls over incineration and other disposal op- likely to face siting difficulties. tions. As one hospital consultant noted, Increased transportation of medical wastes to re- gional facilities, or to facilities that are located out- More and more waste quantities are required to be treated as "infectious," of which smaller per- side a State and in some cases outside of the coun- try, will further increase disposal costs. It is also centages are truly infectious; but, simultaneously, viable treatment and disposal options are being eliminated or made cost-prohibitive (8). 'Ontario, Canada, has a manifest system in place and would like the United States to establish a manifest system of some sort to facili- The concern of some generators of medical waste tate estimating better the amounts of medical wastes entering Can- is that some, if not all, "viable" management op- ada from the United States, in order to better plan for the manage- [ions will become less available(or more costly)due men[of it. Some States(e.g., Massachusetts, New York, Missouri. and New Jersey) are to the adoption of stricter air emission regulations terns of some establishing sort formedicalwaste have established manifest s‘,.•s 27 890958 �w r 28 likely to increase health risks to the public, given re-authorization process.' Other relevant laws the greater potential for accidental exposure due are OSHA, the Clean Air Act, and possibly the to spills and possible illegal dumping or disposal. Toxic Substances Control Act. These concerns provide support for proposals A number of important, related issues noted that require manifest or recordkeeping systems to track the movement of these wastes. The Sen- throughout this paper re-surface as the implications ate passed legislation (S. 2680) in August 1988 that of these areas for possible further policy develop- will require EPA to establish a model tracking sys- ment are discussed. The implications of three of these areas, the definition/classification of medical tern in New York, New Jersey, and Connecticut for medical wastes. Similar legislation is pending wastes, the issue of small quantity generators of n the House (H.R. 3515, H.R. 5119). medical wastes, and research and data needs asso- ciated with medical waste management are dis- cussed briefly to indicate the range of regulatory Policy Issues for Federal Action issues the Federal Government will need to address if it revises or expands its role in medical waste To best address issues associated with these management. trends, at least two types of policy activities are rele- vant: 1) further development and enforcement of The definition of medical wastes under RCRA standard operating procedures(SOPs) by hospitals is of critical importance to determining the type of and other medical waste generators for the han- regulatory effort EPA is likely to undertake. Its dung, storage, treatment, and disposal of these clarification is also likely to facilitate State actions wastes; and 2) further clarification and coordina- and commercial development of medical waste tion of regulatory programs at the local, State, and incineration. Another important dimension of the Federal levels of government. In particular, the pos- medical waste management issue is which types of sibility of further Federal involvement warrants dis- sources should be regulated, i.e., the question of cussion, given the increased public concern over whether small generators of medical wastes should be exempted. Further research into the nature of the management of medical wastes, the increased level of local and State regulatory activity (which the risks (both occupational and environmental) has led to nationwide variation in the treatment of associated with medical wastes, research on new these wastes), the interstate transportation of med- treatment technologies, and performance data for ical wastes, and the current absence of a compre- existing facilities is desirable in order to develop hensive medical waste policy at the national level. more informed and effective policies. The Federal Government could usefully specify Defining/Classifying Medical Wastes its policy(ies) regarding medical wastes in a If infectious wastes are classified and regulated number of areas: 1)designation of a lead author- as hazardous under RCRA, a comprehensive man- ity (presumably EPA) to clarify the definition, agement program is likely for infectious wastes. For classification, and regulation of these wastes; 2) example, regulating infectious wastes as hazardous the establishment of emission standards and ash wastes under RCRA could address transportation regulations for medical waste incinerators, auto- issues associated with infectious waste management. claving/landfilling performance standards, and This would involve: 1) recordkeeping concerning possibly operator training guidelines/regula- the waste transported, its source and delivery tions; 3) handling, storage and transportation points; 2) transportation of the waste only if prop- guidelines/regulations to ensure worker safety erly labeled; 3) compliance with the manifest sys- and possible establishment of some sort of a tem (Section 3002); and 4) transportation only to manifest system; and 4)research and data needs on medical waste practices. Some of these issues 'Some issues.e.g..concerning occupational risks,could be addressed could be addressed under RCRA's current au- under other statutory authority, such as OSHA. The focus here is on RCRA given the primary focus of this paper on waste disposal thorny or could be clarified as part of the RCRA issues. 890958 30 of the two bills with respect to medical waste man- Committee was scheduled to "mark up" H.R. agement. For example, it would require EPA to 3515. issue regulations for all aspects of infectious waste A number of other bills regarding medical waste management including generation, transportation, management issues have been introduced. As in- treatment, storage, and disposal. dicated in table 9, the proposed pieces of legisla- H-R. 3515 distinguishes between medical and tion address a number of aspects of medical waste infectious wastes. Infectious wastes would only management, beyond the definition and classifica- be classified as hazardous wastes under this bill tion issues. Some significant action on several of if they were mixed with hazardous wastes al- the bills appears likely before the current session ready regulated under Subtitle C. In September of Congress ends.' 1988, a substitute for H.R. 3515 added a provi- sion to establish a demonstration tracking system Regulating Small v. Large Generators for medical waste in New York, New Jersey, Con- of Medical Wastes necticut, and the Great Lakes States.' As of Sep- Whether incineration emission standards should tember 21, 1988, the House Energy and Commerce be set at the Federal level and on what basis (tech- (continued from previous page) 'For example,a bill(H.R..5231)to amend the Marine Protection. 21. 1987. on the regulation of infectious wastes. The House Small Research and Sanctuaries Act(Public Law 92-532; MPRSA. corn- Business Subcommittee on Regulation and Business Opportunities monly referred to as the Ocean Dumping Act)of 1972 is expected held a hearing on August 9, 1988, on medical waste issues. to reach the floor of the House before the end of the current session 'The Senate passed legislation (S. 2680)which would establish a The bill would increase criminal penalties for illegal ocean dumping model tracking system for New York State, New Jersey, and Con- of medical waste and provide recovery of damages associated with i0e- necucut. Similar legislation(H.R. 5119), in addition to H.A. 5215, gal dumping. The Senate included similar provisions in the amend- is pending in the House. ments of MPRSA (S. 2030) that it passed in August 1988. .i Table 9.—Legislation Pending In Congress on Medical Wastes (as of Sept. 20, 1988)' Bill number Sponsor(original) Brief summary H.R. 1156 Dwyer(D-NJ) Permits citizens of one State to bring Federal civil action against any person in another State creating a public nuisance through improper management of medical wastes H.R. 3467 Rinaldo (D-NJ) Requires that within 12 months after completing a study of infectious and pathologic waste, EPA must determine whether to regulate these wastes as hazardous wastes under Subtitle C of RCRA H.R. 3478 Saxton (D-NJ) Amends MPRSA(Public Law 92-532).Bane the dumping of medical wastes in ocean and navigable waters H.R. 3515 Luken (D-OH) Amends RCRA(Public Law 94-580)to require EPA to regulate the management of infec- tious and medical wastes; provisions Include definition of waste types by EPA, and establishment of a model manifest system in New York,New Jersey,Connecticut,and the Great Lake States H.R. 3595 Hughes (0-NJ) Requires vessels to manifest the transport of municipal or other nonhazardous wastes to ensure they are not Illegally disposed of at sea H.R. 5119 Florio (D-NJ) Amends RCRA to regulate medical wastes by requiring EPA to establish a model track- ing system for New Jersey and New York H.R. 5130, 5225 Hughes (D-NJ) Amends U.S.C.,Title 18,to provide penalties for Illegal ocean dumping of medical wastes H.R. 5231 Studds (D-MA) Amends MPRSA to increase criminal penalties for illegal ocean dumping of medical wastes and provide for recovery of damages associated with illegal dumping H.R. 5249 Davis(R-MI) Purpose is to protect the Great Lakes from the improper disposal of medical wastes H.R. 5302 Hertel (13-MI) Establishes a pilot program for the tracking of medical wastes in States bordering the Great Lakes S. Res. 470 Rlegb(D-MI) A resolution relating to medical wastes improperly disposed of in the Great Lakes 5. 1751 Lautenberg (D-NJ) Requires vessels to manifest the transport of municipal or other nonhazardous wastes to ensure they are not illegally disposed of at sea S. 2628 Lautenberg(D-NJ) Amends RCRA to establish a pilot program to track medical wastes in New York and New Jersey S. 2726 Dodd (D-CT) Amends RCRA to require EPA to regulate medical wastes S. 2773 Baucus (D-MT) Amends RCRA to define infectious waste and the basis for regulating infectious waste Abbreviations EPA - U.S.Environmental Protection Agency;MPRSA - Marine Protection,Research.and Sanctuaries Act(also referred to as the Ocean Dumping Act);RCRA - Resource Conservation and Recovery Act also referred to as the Solid Waste Disposal Act);U.S.C. - United States Code 'The Senate passed legislation(S.2880)In August 1988.which would establish a model tracking system for New York State,New Jersey.and Connecticut.The Senate also passed in August amendments to MPRSA(S.2030)that include a provision prohibiting the dumping of medical waste In the octane end navigable waters.Similar bole IH.R 3515. M.R.51 t9.N.R.3478,N.R.5231,respectively)are pending in the House. . 890958 • 1 .• p - 29 laws the the waste facility that the manifest form designates Recently, EPA has increased its attention to in- as holding a proper permit.' In addition, waste fectious and medical waste issues. In early ' treatment, storage, and disposal facilities would be EPA assigned for the first time a hill-time staff t.,r- .oted subject to hazardous waste standards and permit- son to handle infectious waste issues. In June, the tions ting procedures.' Agency issued a request for comment on infectious ;lop- waste issues in the Federal Register. Most recently As the Council for State Governments(CSG) has of the Agency has formed a task force to address in- heal noted, existing State infectious waste programs do rs of fectious waste issues. Publicly, the Agency has not not tend to include three requirements usually assn- with hazardous waste laws. These are re- pled out the possibility that ultimately it may is- ciatedtsso- sue regulations, dis- quirements for contingency plans and spill man- althou gh at pr esent its efforts seem tory agement, closures, and financial assurances (4). to be on developing an education program. Iress As noted above, in RCRA, the statutory defini- As noted above, infectious wastes are unlike other aste tion of hazardous waste includes "infectious" as types of hazardous wastes that can be consistently identified by a test. Detection of infectious microbes a defining characteristic.' EPA interprets RCRA in RA as providing it with discretionary authority to clas- landfill leachate is not highly likely given that they are generally less persistent sify infectious wastes as either hazardous wastes or in the environment e of solid wastes.6 EPA, in 1978, did include infectious than toxic substances such as heavy metals, oils, Dots s waste as part of its first set of proposed hazardous solvents, etc. Exposure to sunlight or dry air can ate waste regulations. The final rule published in 1980, render infectious wastes non-infectious. It is also We however, stated that infectious waste regulations true, however, that infectious microbes in medi- s of would be published separately. As the CSG notes, cal `Wastes could multiply and are potentially tagious under certain conditions. In this context,i of . . . [ejight years and two reauthorizations of RCRA developing a separate statutory category for infec- uld later, still no Federal regulations have been promul- tious and medical wastes is seen by some observers of gated (4). as desirable. Applicable hazardous waste provisions w) Instead, in 1986, the EPA issued its Guide for from RCRA Subtitle C could be adopted and ap- Infectious Waste Management stating that propriate adjustments made given the particular na- for ture of the medical wastestream. lop . . . 1v/bile the Agency has evaluated management techniques for infectious waste, considerable evi• It is not entirely clear how EPA may ultimately dence that these wastes cause harm to human define, classify, and regulate infectious wastes (or health and the environment is needed to support if it will). As noted above, EPA's June 2, 1988, Federal rulemaking (emphasis added; 81). Federal Register request for comment on infectious nd RCRA (Section 1004), however, states that the wastes issues indicates the initiation of some infor- term "hazardous waste" refers to a waste with in- mation gathering action on this issue. EPA's posi- r tion in the summer of 1988 was that an education fectious characteristics cs which may program, but not regulation, was justified. Later n • . . . pose a substantial present or potential hazard in 1988, after several congressional hearings, EPA t. to human health or the environment . . . (empha- announced that it would consider the need for Fed- g sis added). eral regulation and established a task force on med- ical waste issues. '421;-S.C. 6924. s- '42 U.S.C. 6924; 6925. Meanwhile, Congress, as part of the RCRA re- to '42 U.S.C. 6903(5). authorization process, will address the issue of in- '42 U.S.C. 6903(5);6921. The hazardous characteristics,of which fectious and medical waste management (H.R. ,,.d infectious is one, listed in 6903 are to be considered when the Ad- is • ministrator of EPA identifies or lists hazardous wastes as per 6921. 3515; S. 2773),' H.R. 3515 is the more detailed „al EPA, however, in their regulatory interpretation, left the infectious characteristic out of the definition of"hazardous waste" (40 CFR 240.101 m 'The House Energy and Commerce Subcommittee on Transpor- ( ))' cation,Tourism,and Hazardous Materials held one hearing October (continued on next page) • 890958 p 37 t. nology- or health-based) is an open issue, as is It is not clear, however, whether these wastes, whether small generators(e.g., doctor offices, home any more than it is clear whether hospital wastes to care) should be exempt from medical waste regu- (especially those which have been treated by auto- s_ lations. While hospitals and clinics may generate claving or some other sterilization process), pose larger quantities of wastes, those generated by a significant contamination problem when land- e smaller facilities may be more susceptible to direct filled." EPA has noted that no groundwater im- I_ public exposure. The two incidents of children play- pacts associated with landfilling any medical wastes f ing with untreated wastes in the summer of 1987, have been identified to date (84). Yet, with little n which focused national attention on medical waste information on the quantities of infectious waste management, occurred outside of doctor offices— from small generators, as well as on the risks of not hospitals (32). these wastes, it is an open question as to what types A problem is how these smaller generators can of controls are appropriate. Controls could focus efficiently and economically dispose of their infec- on handling and direct exposure(through improper d tious wastes. Commercial off-site facilities may not disposal) and/or on environmental risks from dis- be readily available or may be highly costly. Hos- posal of these wastes. pitals which could accept the waste(if there are not The feasibility of controlling small quantity i. State or local regulations prohibiting it) may be generators presents another policy dilemma."Cur- d reluctant to do so for potential liability reasons. rently, the confusion over how best to address this Some hospitals allow affiliated doctors to dispose issue is evident in proposed legislation in some of infectious wastes, and potentially funeral homes States. California, for example, has two bills pend- (with crematories) could also accept wastes from ing, one of which(S. 1448)would prohibit any per- doctor offices. Again, liability issues and other fac- son from disposing of untreated infectious wastes; tors(e.g., the additional staff time for handling such the other (S. 2469) requires the disposal of sharps waste) may make these types of facilities reluctant in puncture-proof containers, except those from pri- to accept such wastes. vate homes, physicians' offices, or health-care fa- The relative risk posed by wastes from home-care cilities. patients and other infectious materials generated Research and Data Needs in homes versus that produced by commercial I generators is not known. Although the public's gen- As noted throughout this paper, little data ex- eral concern about'AIDS and infectious wastes has ists on the management of medical waste. Indeed, i led to a focus on hospital wastes, most treatment the "vital signs" for medical waste management of AIDS is apparently done on an out-patient are thereby difficult to read or interpret. Basic in- basis.10 As hospital stays have generally become formation on sources, amounts, composition, shorter in recent years, home care of patients has and treatment/disposal of medical waste is not increased. Infected wastes from these individuals, known in any useful detail. In addition, insuffi- as well as such items as disposable diapers and femi- cient research data exist to determine to what de- nine sanitary products, are potentially infective gree medical wastes are a public health problem. wastes, and they are directly landfilled in most Information on occupational exposure to hazards cases. Information on appropriate packaging and associated with managing these wastes is not avail- special disposal procedures may be one way to en- able. Comprehensive data on the operation of in- courage prudent disposal of home-care infectious cinerators(e.g., types, comparisons of air emissions wastes." levels for a range of pollutants (including patho- "Items such as disposable diapers and feminine sanitary products "It is also worth noting that CDC studies found that HIV does are not generally considered a serious source of infectious contami- not persist well in the environment, at least not after drying. wit is nation to landfills. It is on this basis that some observers maintain causes a 90 to 99 percent concentration reduction within several hours. that these wastes do not warrant special waste handling procedures, See ref. 77 and that bans of these products are unjustified. "For example. puncture-proof containers could be provided wish "The Association for Practitioners in Infection Control has recently the sale of syringes(which in many areas can only be purchased with proposed a guideline for infection control in home-care which covers a prescription) (48a). waste treatment in this setting(69). 890958 I ' 32 gens), ash content analysis, etc.)do not exist at this 6. comparisons of State regulatory programs, time. specifically to highlight experiences relevant As Ode Keil, Joint Commission on Accredita- to the development of possible Federal pro- grams (e.g., model programs for managing don of Healthcare Organizations, noted at the OTA Workshop on Medical Waste Management, systems, etc.). medical wastes from small generators; mani- festheld July 19, 1988, "We have a problem, but we do not have a scientific analysis of the problem to support development of a rational system." It ap- Concluding Remarks pears it would be highly prudent for Congress This chapter highlights the types of regulatory and Federal agencies to address the inadequacy issues that could be clarified by Congress and/or of data and research, and therefore information, the EPA and other Federal agencies when exam- on medical wastes and their management. This ining the adequacy of current medical waste man- is essential for determining the need for and agement policies. One critical need that is readily nature of any regulatory program for medical apparent and rarely disputed with respect to med- wastes. ical waste management is the need for more infor- A number of possible areas for further research mation on the risks posed by these wastes and on and information gathering exist. Several key areas their actual management, and for more research include: of alternative treatment technologies and manage- ment techniques. Nonetheless, the need for re- 1. developing the basis for a consistent, concrete definition of medical wastes, which all rele- postponing consideration of adopting a compre- search should not be taken as a suggestion for want Federal agencies issue jointly or at least ado r, hensive regulatory program to address medical p waste management. In fact, research efforts 2. the nature and extent of occupational risk, in- could be a part of a regulatory program, if it is cluding risks not only to healthcare workers, promulgated in phases. but housekeeping, maintenance and other relevant workers as well; The most coherent Federal policy for medical 3. use and comparison of different incineration waste management is likely to result only if the va- processes and other technologies, including riety of issues (e.g., the definition, classification, emission rates and health risk assessments of nature of risks, types of available disposal options, these disposal options; and the implications of regulatory action)discussed 4. examination of the use of sewers for medical in this paper are comprehensively addressed. At a waste disposal (e.g., the survival of viruses in minimum, this preliminary assessment of the sta- sewer discharges; problems associated with tus of medical waste management practices in the combined sewer overflows, such as beach United States today indicates that to adequately ad- washups of medical wastes; etc.); dress the public's growing concern over the man- 5. identification of potential waste reduction op- agement of medical wastes, policymakers will need tions for medical facilities; and to address these issues as expediently as possible. 890358 II References 1. American Federation of State, County and Mu- at the Hospital Infectious Waste and Hospital nicipal Employees, AFL-CIO(AFSCME), "Back- Sterilization Workshop, Baltimore, MD, 1988. ground to a Petition to OSHA To Develop an 14. Fossa, A.J., Kerr, R.S., Columbus A.S., and Emergency Temporary Standard for Prevention Waterfall R., "Air Emissions Characterization of of Transmission of Bloodborne Infection in the Municipal Waste Combustors in New York State," Workplace" (Washington, DC: Sept. 19, 1986). paper 87-57.5, presented at the 80th Annual Meet- 2. Basic,J., "Regulating Incinerator Emissions: Per- ing of Air Pollution Control Association, New formance Standards v. Design Standards," paper York, NY, June 1987. presented at the First National Symposium on In- 15. Franklin Associates, Update of Solid Waste Data, cineration of Infectious Wastes,Washington, DC, March 1988. - May 5-6, 1988, 16. Gilmore, C., "Brief Summary of Several Federal 3. Brunner, C., "Biomedical Waste Incineration," Statutes Which Arguably Provide the Federal Gov- , paper presented at the 80th Annual Meeting of the ernment the Authority To Control the Disposal of Air Pollution Control Association, New York, NY, Infectious Hospital Wastes," report to Congress June 1987. (Washington, DC: Congressional Research Serv- e 4. The Council of State Governments, State Infec- ice, The Library of Congress, Aug. 7, 1987). tious Waste Regulatory Programs (Lexington, 17. Gordon,J., "Considerations in the Handling of KY: 1988). Wastes Within the Hospital," paper presented at 5. Cox, K., "Hospital Wastes: How Much Is Gen- the First National Symposium on Incineration of erated and How Are They Managed?" contract Infectious Wastes, Washington,DC, May 5, 1988. supplement for Municipal Solid Waste Assessment 18. Gregory, W., Smith Barney, personal communi- submitted to OTA,June 2, 1988. cation, June 16, 1988. 6. Cross, F., "The Case for Regional Incineration 19. Hagenmaier, J., Kraft, M., Brunner, H., and of Hospital Wastes," paper presented at the First Haag, R., "Catalytic Effects of Fly Ash From National Symposium on Incineration of Infectious Waste Incineration Facilities on the Formation and Wastes, Washington, DC, May 2-4, 1988. Decomposition of Polychlorinate Dibenzo-p-dioxins 7. Cross, F., "Comments on Background Paper," and Polychlorinated Dibenzofurans," Environ- prepared for OTA Workshop on Biomedical Waste ment, Science and Technology 21(11):1080-1084, Management, Washington, DC, July 19, 1988. 1987. 8. Doucet, L., "State-of-the-Art Hospital and Institu- 20. Held,J., "Potential Risk Posed by Hospital In- tional Waste Incineration: Selection, Procurement cinerators in New Jersey," New Jersey Depart- and Operations," paper presented at the 75th An- ment of Environmental Protection, manuscript, nual Meeting of The Association of Physical Plant Apr. 20, 1988. Administrators of Universities and Colleges, 21. Holtzman, E., "D.A. Holtzman Announced In- Washington, DC, July 24, 1988. dictment of Medical Waste Company. . . ," press 9. Doucet, L., "Infectious-Waste Incineration Mar- release, Brooklyn District Attorney's Office, Brook- ket Perspectives and Potentials," paper presented lyn, NY,July 30, 1987. at Wastes-to-Energy'87 Conference,Washington, 22. Holtzman, E., Testimony before the U.S. House DC, September 1987. of Representatives,Committee on Small Business, 10. Doucet, L., Hospital/Infectious Waste Incinera- Subcommittee on Regulation and Business Oppor- tion Dilemmas and Resolutions (Peekskill, NY: tunities, Hearing on Health Hazards Posed in the Doucet & Mainka, P.C., 1988). Generation, Handling, and Disposal of Infectious II. Doucet, L. and Mainka, P.C., personal commu- Wastes, Aug. 9, 1988. nication, Aug. 9, 1988. 23. Infectious Waste News, "Brookhaven, NY, Ac- 12. Doucet, L., and Tilly,J., "Hospital Incinerator cepts Local Hospital's Waste After Banning It Emissions, Risks and Permitting—A Case Study," Three Times From Landfill," Infectious Waste paper presented at the 80th Annual Meeting of Air News, p. 4, June 18, 1987. Pollution Control Association, New York, NY, 24. Infectious Waste News, "Two Children Stuck June 1987. With Untreated Needles While P1::::mg in Trash 13. Fiedler, L., Air Quality Division, Michigan De- Container,"Infectious Waste News, p. 3,June 18, partment of Natural Resources, "Case II: Mercy 1987. Hospital Permit to Install Application," presented 25. Infectious Waste News, "Alexander and Alex- 33 890958 34 ander To Offer Environmental Insurance to Hos- 41. Lauber,J., Battles, D., and Busley, D., "Decon- pitals and Other Polluters," Infectious Waste taminating Infectious Laboratory Wastes by Au- News, p. 6, July 2, 1987. toclaving,"Applied Environmental Microbiology 26. Infectious Waste News, "ECS Offers Insurance 44(3):690-694, September 1982. Coverage for Infectious Waste Industry," Infec- 42. Lee,C.C., et al., "A Review of Biomedical Waste tious Waste News, p. 4, July 2, 1987. Disposal: Incineration," fact sheet (Cincinnati, 27. Infectious Waste News, "Twelve Children Find OH: Office of Research and Development, U.S. and Play With Vials of AIDS-Infected Blood From Environmental Protection Agency, Feb. 19, 1988). Open Trash Bin," Infectious Wastes News, pp. 43. Mainen, E., "Testimony of Eugene Mainen, 2-3, July 2, 1987. Ph.D., Decom Medical Waste Systems, Inc.," pa- 28. Infectious Waste News, "Long Island County Ex- per presented at the OTA Workshop on Medical ecutive Wants To Ban Hospital Incinerators," In- Waste Management, Washington, DC, July 19, fectious Waste News, p. 4, July 30, 1987. 1988. 29. Infectious Waste News, "Infectious Waste Dis- 44. Massachusetts Department of Environmental Qual- posal Crisis Coming to Head," Infectious Waste ity Engineering, "Infectious Hospital Waste," in- News, p. 3, Mar. 10, 1988. temal memorandum, Apr. 16, 1986. 30. Infectious Waste News, "OSHA's Infectious 45. McCormick, R.D., and Maki, D.G., "Epidemi- Waste Rules Need to Cover Refuse Industry, Too, ology of Needlestick Injuries in Hospital Person- NSWMA Says," Infectious Waste News, pp. 1- nel,"American Journal of Medicine 70:928-932, 2, Mar. 10, 1988. 1981. 31. Infectious Waste News, "First Garbage Slick of 46. McDonald, B., Energy Systems Associates, per- , Season Washes Up on New Jersey Shore,"Infec- sonal communication, Sept. 13, 1988. tious Waste News, p. 5, June 16, 1988. 47. Michigan Department of Natural Resources, "Per- 32. Infectious Waste News, "Baltimore County Con- mit to Install Municipal Incinerator at Russell and siders Moratorium on Infectious Wastes Inciner- Ferry Streets, Detroit, Michigan," Apr. 9, 1986. ators," Infectious Waste News, pp. 1-2,June 18, 48. Michigan Department of Natural Resources, "Mu- 1988. nicipal Waste Combustion Study: Assessment of 33. Joint Commission on Accreditation of Hospitals, Health Risks Associated With Municipal Waste Monograph: Managing Hazardous Wastes and Combustion Emissions," September 1987. Materials (Chicago, IL: JCAH, 1986). 48a. Moreland, S., The Markland Group, Washing- 34. Joint Commission on Accreditation of Hospitals, ton,DC,personal communication,Aug. 16, 1988. Accreditation Manual for Hospitals(Chicago, IL: 49. National Committee for Clinical Laboratory Stand- JCAH, 1988). ards, Clinical Laboratory Hazardous Waste 6(15) 35. Jones, W., "Incinerator Operations and Mainte- (Villanova, PA: NCCLS, September 1986). nance," paper presented at the International Sym- 50. National Committee for Clinical Laboratory Stand- posium on Incineration of Industrial and Hazard- ards,Protection of Laboratory Workers From In- ous Wastes, Washington, DC, May 5, 1988. fectious Disease Transmitted by Blood and Tissue 36. Kaiser-Permanente, "Guidelines for Preventing 7(9) (Villanova, PA: NCCLS, November 1987). Transmission of Infections in Health Care Set- 51. National Solid Waste Management Association, tings," 1988. Infectious Waste State Program Survey, Techni- 37. Kalnowski, G., Wiegard, H., and Ruden, H., cal Bulletin 88-2 (Washington, DC: NSWMA, "The Microbial Contamination of Hospital Waste," Feb. 29, 1988). Zbl.Bakt.Hyg.I.Abt.Orig.B 178:364-379, 1983. 52. New York State Energy and Research Develop- 38. Kerr, R., New York State Department of Envi- ment Authority, "Results of the Combustion and ronmental Conservation, personal communica- Emissions Research Project at the Vicon Inciner- tion, Sept. 20, 1988. ator Facility in Pittsfield, Massachusetts," final re- 39. Lauber,J., "Controlled Commercial/Regional In- port (vol. 1), Report 87-16, June 1987. cineration of Biomedical Wastes," paper presented 53. New York State Legislative Commission on Solid at The Incineration of Low-Level Radioactive and Waste Management, "Hemorrhage From The Mixed Wastes 1987 Conference, St. Harles, IL, Hospitals: Mismanagement of Infectious Waste in Apr. 21-24, 1987. New York State," staff report to Assemblyman 40. Lauber,J., New York State Department of Envi- Maurice D. Hinchey, Chairman (Albany, NY: ronmental Conservation, personal communica- LCSWM, Mar. 25, 1986). tion, September 1988. 54. Perkins, J., Principles and Methods of Steriliza- 890958 35 don in Health Sciences, 2d ed. (Springfield, IL: 69. Simmons, B., Trusler, M., and Scott, R., "In- pn Charles C. Thomas Publishers, 1983). \u- fection Control Guidelines for Home Health" 55. Powell, F., "Air Pollutant Emissions From the In- (Methodist Health Systems, Memphis, Tennes- cineration of Hospital Wastes: The Alberta Expert- see), draft manuscript, 1988. ence,"Journal of the Air Pollution Control Asso- 70. Slavik, N., "Report on the Proceedings of the EPA ste ciation 37(7), July 1987. ,t i, Infectious Waste Management Meeting" (Wash- 56. Quinn v. County of Los Angeles, Case No. ington, DC: Nov. 12, 1987). 'S. C669760, L.A. Superior Court of the State of Cali- 71. Slavik, N., Presentation at the Biomedical Waste 8). forma. R•n, 57. Reinhardt, P., "A Comparison of Incineration 2001988 Committee Workshop, UCLA, May 19- a With Other Treatment Methods for Infectious 72. Spurgin, "� Waste" (University of Wisconsin, May 1988). Site it T ea mentOTechnologies,"ff-Site—A m aper With Oat 9, 58. Rogers, H., "Infectious Waste Characterization," paper presented r at Hospital Solid CA, Management Conference, paper presented at the First National Symposium San Francisco, CA, Sept. 20, 1988. al- on Incineration of Infectious Wastes, Washington, 73. T. Super, U.S. Environmental Protection Agency, n- DC, May 5, 1988. communication, 1988. 59. Rutala, W., "Cost-Effective Application of the 74. U.S. Department of Health and Human Services. it- Centers for Disease Control Guidelines for Hand- Centers for Disease Congrol "Guidelines for Iso- n- washing and Hospital Environmental Control," lation Precautions in Hospitals," Infection Con- 2, American Journal of Infectious Control 13:218- trot 4:245-325, 1983. 224, 1984. 75. U.S. Department of Health and Human Services, r- 60. Rutala, W., "Infectious Waste—A Growing Centers for Disease ControUNational Institutes of lem for Infection Control,"ASEPSIS: The Infer- Health, 'Biosafety in Microbiological and Bio- r- Lion Control Forum 9(4):2-6, ,d 1987. medical Laboratories" (Atlanta, GA: 1984). 61. Rutala, W., "Management of Infectious Waste by 76. U.S. Department of Health and Human Services, 3. Per,s United States Hospitals," a delivered to the�- P P Centers for Disease Control "Guidelines for Hand- 28th ICAAC, Los Angeles, CA, 1988. washing and Hospital Environmental Control" Jf 62. Rutala, W., and Sarubbi, F., "Management of :e Infectious Waste From Hospitals," Infectious 77. U.S. Department of Health and Human Services, Waste Management 4(4): 198.203, 1983. Centers for Disease Control, "Recommendations 63. Rutala, W., Stiegel, M., and Sarubbi, F., "De- for Prevention of HIV Transmission in Health- ;' contamination of Laboratory Microbiological g Care Settin "Morbidity andMortaliryWeekly vol.by Steam Sterilization,"Applied and Envi- Report, 36, Aug.. 21, 1987. 1) ronmental Microbiology 43(6):1311-1316, June 78. U.S. Department of Health and Human Services, 1982. Centers for Disease Control, "Update: Universal 64. Sansbury, T., "Hospital To Test Clean Coal Proc- Precautions for Prevention of Transmission of Hu- ess for Waste Burning," The Journal of Com- man Immunodeficiency Virus, Hepatitis B Viz-us, merce, July 19, 1988. and Other Bloodborne Pathogens in Health-Care 65. Schifftner, K., and Patterson, R., "Engineering Settings," Morbidity and Mortality Weekly Re- Efficient Pathological Waste Incinerator Scrub- port, June 24, 1988. bers," paper presented at the First National Sym- 79. U.S. Department of Labor, Occupational Safety posium on Incineration of Infectious Wastes, and Health Administration,Office of Health Corn- Washington, DC, May 5.6, 1988. pliance Assistance, "Enforcement Procedures for 66. Service Employees International Union, AFL- Occupational Exposure to Hepatitis B Virus(HBV) CIO, CLC(SEIU), "Comments on OSHA's Ad- and Human Immunodeficiency Virus (HIV)," vance Notice of Proposed Rulemaking To Control OSHA Instruction CPL 2.2.44A (Washington, Occupational Exposures to Hepatitis B and AIDS" DC: Aug. 15, 1988). (Washington, DC: Jan. 26, 1988). 80. U.S. Department of Labor and U.S. Department 67. Service Employees International Union, AFL- of Health and Human Services, "Protection Against CIO, CLC (SEIU), "Health and Safety Memo- Occupational Ex pore to atitis B Virus randum" (Washington, DC: Jan. 25, 1988). (HBV) and Human Immunodeficiency Virus 68. SEIU Local 250, "Needlestick Survey Results: (HIV),Joint Advisory Notice, Oct. 19, 1987. With San Francisco Area Private, Non-Profit Hospitals" letter from William E. Brock, Secretary of Labor, (Washington, DC: SEIU, December 1987). and Otis R. Bowen, Secretary of Health and Hu- 890958 WI 36 man Services, to healthcare employers concerning of State and Territorial Subtitle D Municipal • this notice, dated Oct. 30, 1987. Landfill Facilities,"draft final report, prepared by 81. U.S. Environmental Protection Agency,Guide for Westat, Inc:, for Office of Solid Waste, October Infectious Waste Management, EPA/530-SW-86- 1987. 014 (Washington, DC: May 1986). 85, Yasuhara, A., and Morita, M., "Formation of 82. U.S. Environmental Protection Agency, Munici- Chlorinated Aromatic Hydrocarbons by Thermal pal Waste Combustion Study, Report to Congress, Decomposition of Vinylidene Chloride Polymer," EPA/530-SW-87-021a, June 1987. Environmental Science Technology 22(6):646-650, 83. U.S. Environmental Protection Agency, "Hospi- 1988. tal Waste Combustion Study, Data Gathering 86. D. Zabinski, U.S. Environmental Protection Phase," final draft(prepared by the Radian Corp.), Agency, personal communication, Sept. 7, 1988. October 1987. 87. D. Zabinski, U.S. Environmental Protection 84. U.S. Environmental Protection Agency, "Survey Agency, personal communication,July 19, 1988. 890958 � yz i — :.. K='mss amt FI.E'jE 0 7.0 VE Wv 'PSIS "'I" PrINC17711 = yIR y ' as l to Y c . .� • Vaste r' {- rCombustion Study:data = x _ ,. athering Phase .. tk-i"m' ' e'er' i - p •. .S'.: v 4. - Of ;.r y,xrgr :y. tk r i N i �_ ♦ry Appendix E s: W.. EPA-450/3-88-017 Hospital Waste Combustion Study Data Gathering Phase Final Report Emission Standards Division US. ENVIRONMENTAL PROTECTION AGENCY Office of Al'and Radiation Office of Air Quality Planning and Standards Research Triangle Park, North Carolina 27711 December 1988 890958 TABLE OF CONTENTS Section Page 1.0 INTRODUCTION 1-1 1.1 Description of the Industry 1-2 1 .2 Waste Characterization 1-6 1.3 References 1-14 2.0 PROCESSES AND EQUIPMENT • 22-1 2.1 Incinerator Technology 2-2 2.1.1 Excess Air Incinerators 2-2 2.1.2 Controlled Air Incinerators 2-5 2.1.3 Rotary Kiln Incinerators 2-8 2.2 Waste Feed and Ash Handling Systems 2-10 2.3 Waste Heat Recovery 2-15 2.4 References 2-16 3.0 AIR EMISSIONS/FACTORS FOR HOSPITAL WASTE INCINERATORS 3-1 3.1 Formation Mechanisms 3-1 3.1.1 Acid Gases 3-1 3.1.1.1 Hydrogen Chloride 3-1 3.1.1.2 Sulfur Dioxide 3-3 3.1.1.3 Nitrogen Oxides 3-3 3.1.2 Particulate Matter 3-4 3.1.3 Trace Metals 3-6 3.1.4 Organic Emissions 3-7 3.1.4.1 Dioxins and Furans 3-9 3.1.4.2 Low Molecular Weight Organic Compounds 3-12 3.1.4.3 Carbon Monoxide 3-12 3.2 Emissions Test Data 3-12 3.2.1 Acid Gases 3-16 3.2.2 Particulate Matter 3-16 3.2.3 Trace Metals 3-24 3.2.4 Organic Emissions 3-26 3.2.5 Carbon Monoxide 3-30 3.2.6 Pathogens Bacteria 3-30 3.2.7 Preliminary Emission Test Data 3-35 3.3 References 3-40 CML.024 i i 83095S TABLE OF CONTENTS . Section page 4.0 CONTROL TECHNOLOGIES AND EFFICIENCIES 4-1 4.1 Source Separation 4-1 4.2 Combustion Control 4.2 4.2.1 Acid Gas Control 4-3 4.2.2 Particulate Matter Control 4-5 4.2.3 Trace Metals Control 4-6 4.2.4 Polycyclic Organic Matter (POM), PCDDs, and PCDFs 4-8 4.3 Flue Gas Controls 4-P7 4.3.1 Fabric Filters (Baghouses) 4-28 4.3.2 Scrubbers 4-30 4.3.3 Afterburners 4-38 4.4 References 4-39 5.0 REGULATORY STATUS AND STRATEGIES 5-1 5.1 Federal Regulations and Programs 5-1 5.1.1 New Source Performance Standards 5-1 5.1.2 National Emission Standards for the Hazardous Air Pollutants 5-2 -5.1.3 Resource Conservation and Recovery Act Requirements 5-2 5.1.4 Prevention or Significant Deterioration Requirements 5-3 5.2 State Regulations and Programs 5-3 5.2.1 State Requirements for Waste Handling 5-3 5.2.2 State Air Emission Requirements 5-4 5.2.3 State Air Toxics Programs 5-5 5.2.4 State Permitting Requirements 5-8 5.3 Foreign Regulations 5-13 5.4 References 5-15 6.0 HOSPITAL WASTE INCINERATOR MODEL PLANTS 6-1 6.1 Population Characteristics 6-1 6.1.1 Population Distribution 6-1 6.1.2 Model Incinerator Stack Parameters 6-6 6.1.3 Model Incinerator Operating Parameters 6-15 6.2 References 6-20 APPENDIX A - STATE REGULATIONS PERTAINING TO INFECTIOUS WASTE MANAGEMENT A-1 • CML.024 iii 89095 TABLE OF CONTENTS Section Page APPENDIX B - ADDITIONAL HOSPITAL WASTE INCINERATION EMISSION DATA . B-1 B-1 Introduction B-2 B-2 Test Data for the Hospital Refuse Incinerator at Sutter General Hospital , Sacramento, CA R-3 ► B-3 Test Data for the Refuse Incinerator at Stanford University Environmental Safety Facility, Stanford, CA R-19 • { iv 890958 • LIST OF TABLES Table P 1-1 Waste Generation Rates for Seventeen Hospitals in the State of Florida 1-4 1-2 Hospital Waste Characterization 1-7 1-3 Canadian Characterization of Biomedical Waste 1-8 1-4 Incinerator Institute of America Solid Waste Classifications 1-11 1-5 Ultimate Analyses of Four Plastics 1-13 3-1 Pollutants Measured/Tested 3-2 3-2 Test Site Design and Operating Parameters for Comprehensive Emission Test 3-14 3-3 Data/Factors for Hydrogen Chloride Emissions from Hospital Waste Incinerators 3-17 3-4 Data/Factors for SO2 and NOx Emissions from Hospital Waste Incinerators 3-20 3-5 Data/Factors for Particulate Emissions from Hospital Waste Incinerators 3-21 3-6 Data/Factors for Trace Element Emissions from Hospital Waste Incinerators 3-25 3-7 Data/Factors for Chlorinated Dibenzo-p-Dioxins Emissions from Hospital Waste Incinerators 3-27 3-8 Data/Factors for Chlorinated Dibenzofurans Emissions from Hospital Waste Incinerators 3-28 3-9 Fabric Filter Dioxin/Furan Ash Analysis for Cedar Sinai Incinerator 3-29 3-10 Emission Factors for Selected Organic Low Molecular Weight Organics from Hospital Waste Incinerators 3-31 3-11 Emissions/Factors for Carbon Monoxide and Hydrocarbon Emissions from Hospital Waste Incinerators 3-32 CML.024 V 890938 t LIST OF TABLES Table Page 3-12 Incinerator Characteristics 3-33 3-13 Efficacy of Incinerator Operations in the Destruction of the Microflora Associated with Municipal Solid Waste 3-34 3-14 Preliminary HC1 and PM Emissions Test Data 3-36 3-15 Preliminary Metals Emissions Test Data 3-37 3-16 Preliminary Dioxin and Furan Emissions Test Data 3-38 3-11 Preliminary Results of Three Biomedical Waste Incinerators Located in Canada 3-39 5-1 Guideline Emission Limits for Incinerators Burning Hospital Waste 5-6 5-2 Acceptable Annual Ambient Concentrations Reported for Selected Pollutants 5-7 { 5-3 Foreign Emission Regulations for Hospital Waste 5-14 6-1 Summary of Model Incinerator Stack Parameters 6-14 • 6-2 Summary of Emissions Factors and Rates for Hospital Incinerator Model Sizes 6-17 vi CML.024 890958 LIST OF TABLES Table Page B-1 Sutter General Hospital - Average Refuse Feed Rate to Incinerators During Test Period B-3 B-2 Daily Average Stack Conditions for Incinerator at Sutter General Hospital B-4 B-3 Daily Average Concentrations of Selected Gaseous Air Pollutants from the Sutter General Incinerator B-5 R-4 Daily Average Concentrations of Oxygen, Carbon Dioxide, Carbon Monoxide, Oxides of Nitrogen, Sulfur Di oxide, Total Hydrocarbons, Particulate Matter and Hydrochloric Acid in the Stack Gas at Sutter General Hospital , Sacramento, CA B-6 B-5 Sutter General Hospital - Particulate Matter and Hydro- chloric Acid Concentrations and Mass Emission Rates . . R-7 8-6 Sutter General Hospital - PCDD/PCDF Mass Emission Rates . B-7 Sutter General Hospital - PCDD/PCDF Concentrations in Stack Gas ▪ B-9 B-8 Sutter General Hospital - PCDD/PCDF Concentrations in Stack Gas • B-10 8-9 Sutter General Hospital - PCDD/PCDF Mass Emission Rates in Stack Gas . B-11 B-10 Sutter General Hospital - PCDD/PCDF Concentrations in Stack Gas (Corrected to 12 percent CO2) . 8-12 B-11 Sutter General Hospital PCDD/PCDF Concentrations in Stack Gas • 8-13 8-12 Sutter General Hospital - Mass Emission Rate of Trace Metals in Stack Gas . 8-14 8-13 Sutter General Hospital - Concentrations of Trace Metals in Stack Gas • B-15 B-14 Sutter General Hospital - Mass Emission Rates of Arsenic, Cadmium, Chromium, Iron, Manganese, Nickel and lead in Stack Gas . . . R-16 8-15 Sutter General Hospital - Concentrations of Arsenic, Cadmium, Chromium, Iron, Manganese, Nickel and Lead in Stack Gas . . vi i 890953 LIST OF TABLES Table Page B-16 Sutter General Hospital - Mass Emission Rates of Selected Chlorinated and Aromatic Organic Compounds . Based on Analysis of Resin Samples B-17 F € B-17 Sutter General Hospital - PCDD/PCUF Concentrations , in Bottom Ash Sample B-18 8-18 Stanford University - Daily Average Operating Parameters R-20 B-19 Stanford University - Daily Average Concentrations of Oxygen, Carbon Dioxide, Carbon Monoxide, Oxides of Nitrogen, Sulfur Dioxide, Total Hydrocarbons , Particulate Matter and Hydrochloric Acid in the Stack I Gas . B-21 8-20 Stanford University - Concentrations and Mass Emission Rates of Particulate Matter B-22 B-21 Stanford University - Concentration and Mass Emission Rates Hydrochloric Acid B-23 B-22 Stanford University - PCDD/PCDF Mass Emission Rates . 8-24 A B-25 C 8-23 Stanford University - PCDD/PCDF Concentrations in Gas (corrected to 12% CO2) B-26 A 8-27 9-24 Stanford University - Mass Emission Rates of Selected Metals in the Stack Gas R-28 Y B-25 Stanford University - Concentrations of Selected Metals ` in the Stack Gas Concentrations 8-29 . B-26 Stanford University - Mass Emission Rates of Selected Chlorinated and Aromatic Compounds Based on Analysis of Resin Samples B-30 B-27 Stanford University - PCDD/PCOF Concentrations in Bottom Ash and Scrubber Effluent - 9-31 viii 890958 • LIST OF FIGURES Ficgre -2-3 nt 2-1 Multiple-Chamber Pathological Waste Incinerator. . . . . . . . . . . 2-2 In-Line Multiple-Chamber Incinerator.. . . . . . . . . . . . . . . . . . . . . 2 3 2-4 2-3 Schematic for Controlled Air Incinerator. . . . . . . . . . . 2-4 Adiabatic Temperature Versus " " • • • 2-6 Excess Air for a Controlled Air Incinerator. . . . . . .. . 2-5 Refractory Rotary Kiln System. . . . .. . . . ... . . . . . . . . . 2-6 Schematic and Example of a Mechanical Loading System. . . . . . 2-11 3-1 Impact of Temperature and Fuel Nitrogen on NOx Emissions 2 13 for Excess Air Conditions. . . . . . . , 3-2 Process Schematic for Primary " ' 3 5 Combustion. . . . . . .. . . . , Chamber Hospital Waste . . . ... . . . . . .... . . . . ...• 3-8 3-3 Hypothetical Mechanisms of CDD/CDF Formation Chemistr • 4-1 Fraction of As and Sb Collected with Fume as a Function 3-11 of the Extent of Total Ash Vaporization (Data Points) 4-7 4-2 Concentration of Selected Elements in Ultra-fine Particulates as a Function of Reciprocal Particle Diameter 4-9 4-3 Adiabatic Equilibrium Species Distribution 4-13 4-4 First Stage Hydrocarbon Production 4-15 4-5 One Possible Formation Mechanism for 2,3,7,8-TCDO. . . . . . . . . 4-17 4-6 Benzo(a)Pyrene Emissions from Coal, Oil, and Natural Gas Heat-Generation Process 4-19 4-7 Variation of Adiabatic Flame Temperature Theoretical Air and Percent Moisture in the tNSWhercent 4-23 4-8 Hydrocarbon Breakthrough as a Function of Percent Theoretical Air 4-25 4-9 Typical Fabric Filter System 4-29 4-10 Open Spray Tower Scrubber 4-31 CML.024 ix 890958 LIST OF FIGURES Figure Page 4-11 Fixed Orifice Scrubber 4-32 4-12 Baffle Impingement Scrubber 4-33 4-13 High Energy Venturi Scrubber 4-34 4-14 Teller Dry Scrubbing System 4-37 6-1 Distribution of Hospital Sizes According to Bed Number 6-3 6-2 Waste Feed Rate Distribution of Incinerators in N.Y. Database by Number 6-4 6-3 Waste Feed Rate Distribution of Small (Less Than 200 lb/hr) Incinerators in N.Y. Database. by Number 6-5 6-4 Waste Feed Rate Distribution of Incinerators in N.Y. Database by Capacity 6-7 6-5 Average, High, and Low Stack Heights According to Selected Feed Rate Ranges 6-8 6-6 Average, High, and Low Stack Gas Exit Temperature. According to Selected Feed Rate Ranges 6-10 6-7 Average, High, and Low Stack Gas Exit Velocities According to Selected Feed Rate Ranges 6-11 6-8 Average, High, and Low Stack Diameters According to Selected Feed Rate Ranges 6-13 6-9 Annual Operating Hours According to Selected Feed Rate Changes 6-16 ' x CNL.024 890958 1.0 INTRODUCTION • { This report contains the results of a study of air emissions from hospital waste combustion. It represents an effort to gather currently available data in a manner that will allow the EPA to assess the need for and feasibility of regulating multipollutant emissions from hospital waste combustion. The work was performed by Radian Corporation under contract to EPA's Pollutant Assessment Branch of the Office of Air Quality Planning and Standards (OAQPS). During the course of this study, information was gathered from State and local environmental agencies, from vendors of incineration equipment, from the open technical literature, from the American Hospital Association, and from visits to three incineration facilities. Information was sought concerning feed characteristics, combustor designs and operating characteristics, emissions of air pollutants, applied and potential control technology, numbers and locations of hospital waste combustors, and applicable regulations. In addition, parameters needed to model Eexposure and health risk have been developed for use in EPA' s Human Exposure Model . A final draft report for this study was prepared in October 1987. This report was widely circulated by EPA/OAQPS for review and comments by EPA Regional Offices, State agenices, related trade associations, incinerator vendors, and interested individuals. Comments received were evaluated and incorporated into this report where appropriate. While some new emissions data were received, they were of a preliminary nature and thus have been reported as a separate category of data in Section 3. The remainder of Section 1 is devoted to a description of the industry (Section 1 .1 ) and characterization of hospital waste (Section 1 .2). Section 2.0 contains information about the processes and equipment used for hospital waste combustion. Data gathered concerning air pollutants emitted from hospital waste incinerators and their formation in the combustion process are presented in Section 3.0. Section 4.0 contains a discussion of control techniques and possible control efficiencies. environmental regulations affecting hospital waste combustion are presented in Section 3.0. Section 4.0 contains a discussion of control techniques and possible control efficiencies. Environmental regulations affecting hospital waste combustion are presented in Section 5.0. Model plants suitable for EPA's use in assessing regulatory strategies are developed in Section 6.0. CML 1_1 890958 1.1 DESCRIPTION OF THE INDUSTRY 'Hospital waste' refers to wastes produced by a hospital or hospital - type facility. These wastes include both infectious wastes (i.e. , materials which come in contact with hospital patients and which have a potential to carry disease-producing organisms) and non-infectious or general house- keeping wastes. The volume of infectious waste produced by a facility can vary widely, depending primarily on guidelines or practices employed. Based upon CDC guidelines, infectious waste would only comprise 3 to 5 percent of the total hospital waste.' Conversely, hospital infectious waste could com- prise 80 percent or more of total waste based upon the Universal Isolation Precaution Guidelines of August 1987. In addition to these guidelines, the waste segregation practices employed by hospitals will influence the total volume of waste which is considered infectious; Although segregation of infectious and non-infectious waste introduces additional handling complications and expense, comments received from the American Society for Hospital Engineering (of the American Hospital Association) indicate that most hospitals have waste segregation programs in place.2 In many States, laws have been enacted in the past ten years which prohibit the disposal of infectious wastes in landfills. To qualify for disposal , wastes must first be rendered innocuous. The two primary sterilization methods used by hospitals are autoclaving and incineration. Sterilization with ethylene oxide and waste shredding followed by chemical disinfection are available alternatives but are not commonly used. Due to limitations associated with autoclaving (i.e., limited capacities, handling problems, and questionable effectiveness) and ethylene oxide units (i .e. , worker health risks), incineration has become the most practical waste sterilization and disposal option for many hospital facilities,3 according to authorities in Illinois. Incineration reduces waste volumes by up to 90 percent. Hence, the volume and cost of ultimate disposal of residual wastes in a landfill can be reduced significantly by this method. An additional benefit of incineration systems, in some cases, is that they can be designed for heat recovery with the potential to supply a portion of the hospital 's steam or hot water requirements. 890958 CML.026 1-2 The total number and capacity of hospital waste incinerators in the United States is uncertain. As of 1985, there were a reported 6,872 1 hospitals in the nation with 1,318,000 beds.4 Estimates of waste generation rates range from about 8 to 45 lb/bed/day.5 ,6,7 For example, Table 1-1 shows hospital waste generation per bed for seventeen hospitals in the State of Florida. The waste generation rate for these seventeen hospitals ranged from 8 to 45 lb/bed/day and averaged 23 lb/bed/day. Using this average generation rate and an average occupancy rate of 69 percent, the total hospital waste generation rate in the United States is estimated to be about 10,500 tons/day. However, not all hospital waste is sent to incinerators, as discussed above. To estimate actual incinerator tonnage, this rate would need to be reduced by the amount of infectious waste handled by other treatment processes and the amount of general waste that is segregated and sent via trash disposal to landfills. Unfortunately, it is not possible to estimate these quantities based on the information gathered to date. As a point of reference, however, about 18,000 tons/day of municipal solid waste were disposed of by combustion by municipalities in 1985.8 With regard to geographic distribution, hospitals are located in every State as well as in the District of Columbia. At least one hospital was located in almost all metropolitan and non-metropolitan statistical areas in 1985 according to American Hospital Association statistics9 Of the total number of hospitals, approximately 53 percent were located in metropolitan statistical areas with the balance in non-metropolitan areas: Detailed statistics are available only for community hospitals, which comprised over 83 percent of the total number of hospitals in 1985. During the 1975 to 1985 period, the number of community hospitals declined by 2.4 percent; the total number of beds increased by 6.2 percent, however, a shift attributed to hospital closures, mergers, and conversion to nonacute-care facilities.10 Although the occupancy rate for community hospitals declined from 75 to about 65 percent, the number of surgical operations (which produce higher levels of infectious waste) increased by almost 21 percent. Taking these off-setting factors into account, the CML.026 1-3 890958 • LSti 1-1. MAla GlNINAS20N lazes 101 102a11222 IDQRAts a s WAIT al FLRDAA° Average Mpttal Pathological Iet..tieas General Feed Cardboard Total I Beds 1/Bed/Day Mist Jewish N oum 6 bspttal — 23 1,330 6,120 403 7,098 376 21 Cant lest ipttal — 3206 2,367° — — 2,287 127 23 Mtn General 2 613 3,370° — — 6,237 237 II North line General 17 93 3,440d — 301 3,033 128 23 S outh Mien Neepttal — 300 3,600 1,700 $67 3,967 330 17 Cedars Medical Center — 900 6,800 300 1,000 9,200 333 26 Madmen Nopita' - - et Nisei — 3,140 6,386° — — 7,726 300 26 less— palm 27. Institute -- 1036 2,306° — — 2,407 100 26 Lakin General Wpltal 102 132 332 102 102 N/A 60 N/A Mind Children's 3 103 1,613 100 ' 1 1,620 137 12 Can Center Marital 28 1,800° 2,392 — 6,683 100 63 North Gables Nopltal 7 4.7 203 630 29 676 33 16.3 Kist Institat• s-a 1,200b 7,440° st W — — 6,660 la 43 touhedu pines General 21 137 1,330° — — 1,308 193 g Janes Archer Smith 29 837 143 71 143 1,243 SO 16e Baptist l..pital _ et Ntan. 1,300 730 3,300 4,300 2,000 16,230 383 37e Sm.tsr's Nopttal •-• 333b 2,160° 3,866 — 6,301 163 39° ti.terwat. 7. Sates are in tbldn unless meted otherwise. bSat lmld.. Pathala{iial wastes. °Meant is-lad Fee wastes.d end Cndbeard ss. 's dlraet inelud.a Fad wastes. °Aar inetae4u Cad►eed wastes. s.n guestimating arrived otter the 'amputations were aapletad an se ate met taaldad is the average 1M/bed/day figure. CML.026 1-4 690955 overall hospital waste generation rate appears to have remained relatively constant over this 10-year period. No factors were identified which would significantly change this trend in the near future. No comprehensive information was found during this study regarding the total population of hospital waste incinerators in the nation. One manufacturer's representative estimated that over 90 percent of operating hospitals have an incinerator on-site, if only a small retort-type unit for pathological or special wastes." The number of larger, controlled air type incinerators operating on hospital wastes is not known. However, based on discussions with two of the leading controlled-air incinerator manufacturers, it is estimated that at least 1 ,200 of these systems have been installed at . United States hospitals over the past 2.0 years.12_,13 This implies that there It are approximately 5,000 retort-type incinerators installed. While some of these units have been retired, a great majority are felt to be currently in operation.14 Some insight into the incineration population distribution was gained by examining a recent New York State data base which was developed from an in-state survey of over 400 hospital waste incinerator units. This data base, and the analysis conducted by Radian Corporation during this study, are described in detail in Section 6.1. Highlights of the analysis are as follows: o Almost 6U percent of the New York incinerators have design feed capacities of less than 200 lb/hr. o The population distribution is bimodal with respect to feed capacity, with peaks in the 50 to 74 lb/hr range and in the 100 to 124 lb/hr range. o About 14 percent of the incinerator population in New York is above 600 lb/hr feed capacity and about 6.5 percent is above 1,000 lb/hr feed capacity. A comparison of the New York and total U.S. hospital populations indicates that the two populations have similar overall distributions although there is a greater proportion of large hospitals above the 500-bed size in NY than in the nation as a whole. The conclusions drawn from this analysis is that CHL.026 1-5 690958 there are many small hospital waste incinerators but that the larger incinerators account for a significant fraction of total waste handling capacity. 1.2 WASTE CHARACTERIZATION Hospital waste is characteristically heterogeneous, consisting of ofjects of many different sizes and composed of many different materials. The daily activities and procedures within a hospital can vary dramatically from day-to-day, thus making it difficult to predict what will be thrown away. During the course of this study, very little data were found on the composition of hospital waste. This may be due to the fact that the amount of sampling and chemical analyses required to generate representative characterization data would be extensive and costly. In addition, industry practice for many years has been to utilize the simplified waste classification system developed by the Incinerator Institute of America ( IIA) , discussed below, rather than to sample and chemically analyze waste. Table 1-2 contains one general breakdown of the composition of typical hospital waste. As discussed above, the experience of hospitals in Illinois indicates that above 85% of & hospital 's waste stream can be categorized as general refuse, while the remaining 15% is contaminated with infectious agents,15 This is only a generalization, however, and actual wastes from a given hospital can vary significantly from day to day and from hour to hour. For example, refuse collected after a major surgical procedure, such as a heart transplant, may contain significantly more infectious wastes and disposable plastics than is usually generated in a routine operation.16 Also, to the extent that the infectious waste is mixed with a hospital 's general waste, more waste will be generated that is considered infectious.17 Most of the public attention concerning hospital waste management has centered on infectious waste. Unfortunately, a number of general and vague terms are used to refer to these wastes, including "pathological waste," "biological waste," "hazardous waste," "biomedical waste," and "contaminated waste." In Canada, the term biomedical waste is popular and a color-code classification scheme for the waste has been developed as shown in Table 1-3. In the United States, all these categories of wastes are generally classified as "red bag" waste.18 890958 CML.026 1-6 TABLE 1-2. HOSPITAL WASTE CHARACTERIZATIONa F Approximate Product Percent by Weight" Paper 65 Plastic 30 Moisture 10 Other 5 aReference 19 . "Percentages do not add to 100 since they are approximations. CML.026 1-7 690958 TABLE 1-3. CANADIAN CHARACTERIZATION OF BIOMEDICAL WASTEa Typical Component weight percent Waste Class Component Description (as fired) Al Human Anatomical 95-100 (Red Bag) Plastics 0-5 Swabs, Absorbents 0-5 Alcohol, Disinfectants 0-0.2 A2 Animal Infected (Orange Bag) Anatomical 80-100 Plastics 0-15 Glass 0-5 Beddings, Shavings, Paper, Fecal Matter 0-10 A3a Gauze, Pads, Swabs, (Yellow Bag) Garments, Paper, Cellulose 60-90 Plastics, PVC, Syringes 15-30 Sharps, Needles 4-8 Fluids, Residuals 2-5 Alcohols, Disinfectants 0-0.2 A3b Plastics 50-60 (Yellow Bag) Sharps 0-5 Lab Waste Cellulose Materials 5-10 Fluids, Residuals 1-20 Alcohols, Disinfectants ' 0-0.2 Glass 15-25 A3c Gauze, Pads, Swabs 5-30 (Yellow Bag) Plastics, Petri Dishes 50-60 R&D on DNA Sharps, Glass 0-10 Fluids 1-10 B1 Non-infected (Blue bag) Animal Anatomical 90-100 Plastics 0-10 Glass 0-3 Beddings, Shavings, Fecal Matter 0-10 aReference .6 . CML.026 1-8 890958 In Europe, hospital wastes are divided into the general categories of normal housekeeping wastes and "hazardous" wastes. The latter category consists of bacterially infected pathological waste, oil and chemical waste, and radioactive isotopic contaminated waste.2D A typical cross-section of this type of waste has included the following items: Disposable linens Paper Flowers Waste food Cans Diapers Plastic cups Syringes Scalpels Tweezers Rubber gloves Pathological objects Blood test tubes • Test tubes from miscellaneous service Petri dishes Dropper bottles Medicine bottles Drop infusion equipment • Transfusion equipment Suction catheters Bladder catheters Urinal catheters Colostomi bags The general practice in the United States is to classify wastes according to the IIA system described in Table 1-4. The popularity of this system is reinforced by the fact that most incinerator manufacturers rate their equipment in terms of these categories.21 While useful for general design purposes, the IIA classification scheme does not address concerns such as the plastics content of waste or possible hazardous components. Hospital wastes typically can contain about 20 percent plastics with levels as high as 30 percent being reported.22 The types of plastic most commonly encountered include polyethylene, poly- propylene, and polyvinyl chloride.23 Potential combustion products from CML.026 1-9 890958 the burning of these plastics, including hydrochloric acid and toxic air contaminants, are discussed in Section 3.1. Ultimate analyses for four common plastics are shown in Table 1-5. Hospital waste may also contain potentially toxic components. For example, red bag waste in the United States may contain potentially toxic compounds generated by hospital operations that are currently exempt from regulations under the Resource Conservation and Recovery Act (RCRA) .24 Such chemicals include waste pharmaceuticals, cytotoxic agents used in chemotherapy, and anti-neoplastic agents.Z5 Mercury from dental clinics • and other heavy metals used in hospitals may also cause air emission concerns if they enter the combustor along with other hospital wastes. • CML.026 1-10 690955 TABLE 1-4. INCINERATOR INSTITUTE OF AMERICA SOLID WASTE CLASSIFICATIONSa Type 0 Trash, a mixture of highly combustible waste such as paper, cardboard, cartons, wood boxes, and combustible floor sweepings from commercial and industrial activities. The mixtures contain up to 10 percent by weight of plastic bags, coated paper, laminated paper, treated corrugated cardboard, oily rags, and plastic or rubber scraps. This type of waste contains 10 percent moisture, 5 percent incombustible solids and has a heating value of 8,500 Btu per pound as fired. Type 1 Rubbish, a mixture of combustible waste such as paper, cardboard cartons, wood scrap, foliage, and combustible floor sweepings, from domestic, commercial , and industrial activities. The mixture contains up to 20 percent by weight of restaurant or cafeteria waste, but contains little or no treated papers, plastic, or rubber wastes. This type of waste contains 25 percent moisture, 10 percent incombustible solids, and has heating value of 6,500 Btu per pound as fired. Type 2 Refuse, consisting of an approximately even mixture of rubbish and garbage by weight. This type of waste is common to apartment and residential occupancy, consisting of up to 50 percent moisture, 7 percent incombustible solids, and has a heating value of 4,300 Btu per pound as-fired. Type 3 Garbage, consisting of animal and vegetable wastes from restaurants, cafeterias, hotels, hospitals, markets and like installations. This type of waste consists of up to 70 percent moisture, up to 5 percent incombustible solids, .and has a heating value of 2,500 Btu per pound as-fired. Type 4 Human and animal remains, consisting of carcasses, organs, and solid organic wastes from hospitals, laboratories, abattoirs, animal pounds, and similar sources, consisting of up to 85 percent moisture, 5 percent incombustible solids, and having a heating value of 1,000 Btu per pound as fired. CML.026 1-11 890955 r • • TABLE 1-4. INCINERATOR INSTITUTE OF AMERICA SOLID WASTE CLASSIFICATIONSa (Continued) Type 5 Byproduct waste, gaseous, liquid or semiliquid, such as tar, paints, solvents, sludge, fumes, etcs. , from industrial operations. Btu values must be determined by the individual materials to be destroyed. Type 6 Solid bydproduct waste, such as rubber, plastics, wood waste, etc., from industrial operations. Btu values must be determined by the individual materials to be destroyed. aReference 26 . CML.026 1-12 890958 TABLE 1-5. ULTIMATE ANALYSES OF FOUR PLASTICS' (Weight Percent) Polyvinyl Polyethylene Polystyrene Polyurethane Chloride Moisture 0.20 0.20 0.20 0.20 Carbon 84.38 86.91 63.14 45.04 Hydrogen 14.14 8.42 6.25 5.60 Oxygen 0.00 3.96 17.61 1.56 Nitrogen 0.06 0.21 5.98 - 0.08 Sulfur 0.03 0.02 0.02 0.14 Chlorine tr tr 2.42 45.32 Ash 1.19 0.45 4.38 2.06 Higher heating 19,687 16,419 11,203 9,754 value, Btu/lb 'Reference 27. CML.026 1-13 820958 1.3 REFERENCES 1. Doucet, L. G. "Infectious Waste Incineration Market Perspectives and Potentials," presented at the Waste-to-Energy 1987 Conference Exploring the Total Market, Washington, D. C. September 1987. 2. Private communication between R. Morrison, II. S. Environmental Protection Agency and M. Ficht, American Society for Hospital Engineering of the American Hospital Association, June 7, 1988. 3. Brenniman, G. R. ; R. J. Allen, and P. J. Graham. "Disposal of Infectious Hospital Waste: The Problems in Illinois." The Environmental Professional , Vol . 6 , 1984, pp. 250-251. 4. American Hospital Association. Hospital Statistics: 1986 Edition. Chicago, Illinois , 1986, p. 2. 5. Faurholdt, G. "European Experience with Incineration of Hazardous and Pathological Wastes." Presented at the 80th Annual Meeting of the Air Pollution Control Association, New York, June 21-26 , 1987. 6. Doucet, L. G. "Controlled Air Incineration: Design, Procurement, and Operational Considerations." Prepared for the American Society of Hospital Engineering of the American Hospital Association. Technical Document Series, Technical Document Number: 055872, January 1986. 7. Cross/Tessitore and Associates. "Centralized Incinerator Study." South Florida Hospital Association. December 16, 1985. 8. Radian Corporation. Municipal Waste Combustion Study: Characterization of Municipal Waste Combustion Industry. EPA 530-SW-87-021h, July 1987, pp. 2-5. 9. Reference 3. 10. Reference 4, p. xvii . 11. Private communication between E. Aul, Radian Corporation and R. Leine, Southern Corporation, August 25, 1987. 12. Consumat Systems, Inc. Installations List. Richmond, Virginia. Received by Radian Corporation in June 1987. p 1. 13. •Private communication betwwn E. Aul , Radian Corporation and S. Shuler, Ecolaire Combustion Products, Inc. , August 25, 1987. 14. Reference 11. 15. Reference 3. CML.026 1-14 • 890958 • 16. Doyle, B. W. ; D. A. Drum, and J. D. Lauber. "The Burning Issue of Hospital Waste Incineration." presented at Israel Ecological Society Third International Conference, Jerusalem, Israel , June 1986. 17. Brunner, C. R. , "Biomedical Waste Incineration." Presented at the 80th Annual fleeting of the Air Pollution Control Association, New York, June 21-26, 1987. 18. Reference 17. 19. Jenkins, A. C. , "Evaluation Test on a Hospital Refuse Incinerator at Saint Agnes Medical Center, Fresno, CA." California Air Resource Board, Stationary Source Division, January 1987. tE 20. Reference 5. 21. Reference 6. 22. Murnyak, G. R. , and D. C. Gazenich. "Chlorine Emissions from a Medical Waste Incinerator," Journal of Environmental Health, Sept/Oct 1982. 23. Reference 17 24. Lauber, J. U. "Controlled Commercial/Regional Incineration of Biomedical Wastes." Presented at the Incineration of Low Level Radioactive and Mixed Wastes, St. Charles, Illinois. April 21-24, 1987.. 25. Reference 5. 26. Reference 6. 27. Kaiser, E. R. and Carotti , A. "Municipal Incineration of Refuse with Two Percent and Four Percent Additions of Four Plastics: Polyethylene, Polyurethane, Polystyrene, and Polyvinyl Chloride, "Proceedings of the 1972 National Incinerator Conference," June 1972. p9s. 230-4S. California Air Resources Board. Air Pollution Control at Resource Recovery Facilities. May 24 , 1984 • CML.026 1-15 890958 2.0 PROCESSES AND EQUIPMENT The primary objectives of hospital waste incinerators are (1) to render the waste innocuous, and (2) to reduce the size and mass of the waste. These objectives are accomplished by exposing the waste to high temperatures over a period of time long enough to destroy threatening organisms and by burning all but the incombustible portion of the waste. As discussed in Section 1.1, incineration has become the primary sterilization and disposal option for many hospital facilities. The design of a hospital waste incinerator, like any combustion system, requires consideration of a number of interrelated factors including residence time, temperature, and turbulence (i .e., the three "T"'s of combustion) . Other factors which can influence combustion performance are fuel feeding patterns, air supply and distribution, heat transfer, and ash disposal .1 Like municipal solid waste (MSW), hospital waste is a difficult. fuel to combust relative to conventional fuels such as oil , gas, coal , or wood. Some of the problems associated with.hospital wastes which must be considered by the combustion system designer and equipment operator are: o Fuel of non-homogenous and variable composition - The physical and chemical composition of hospital waste is highly variable. Furthermore, the waste feed consists of chemically diverse articles of different sizes and shapes. Hospital waste is seldom pre-processed; it is burned in bulk on a mass feed basis. Non-homogenous and variable compositions should be accounted for in system design and operation to ensure that these factors do not pose problems in feeding, flame stability, particle entrainment and emission control . o Variable ash content - Hospital waste contains varying amounts of glass, metals and ceramics which are not consumed in the combustion process. Fluctuations in ash composition and combustion temperatures can lead to clinker formation, slagging and fouling in some systems. To avoid these problems, primary combustion chamber temperatures are generally maintained below 1800"F.' However, this tends to reduce carbon burnout and the overall energy utilization efficiency. o Low heating value - Hospital wastes often have low heating values due to high moisture contents. This causes flame stability problems and, in some cases, it becomes necessary to fire an auxiliary fuel to maintain proper combustion conditions. CML.026 2-1 890958 Alternately, dry waste batches (especially those with a high plastics content) can produce high flame temperatures which result • in overheating of the hearth or other combustion system components. To avoid these problems, the combustion conditions (principally excess air, air distribution, and auxiliary fuel firing rate) must be controlled closely. o Corrosive materials - Hospital wastes contain varying amounts of fluorine and chlorine, principally from plastics. The acid gases produced from the incineration of these materials can corrode combustion and air pollution control equipment, especially convective heat transfer tubes. For this reason, hospital incinerators should be constructed of corrosion - resistant materials. 2.1 INCINERATOR TECHNOLOGY There are three major types of incinerators currently used to incinerate hospital wastes in the United States: excess air, controlled air, and rotary kiln. The design and operating principles for each of these three major types are discussed in this section. 2.1.1. Retort Incinerators Retort incinerators are variable capacity units which are mostly field fabricated. These units also typify older, existing hospital incinerators. They are also referred to as 'pyrolitic,' 'multiple chamber,' and 'excess air" incinerators in the literature. These incinerators appear as a compact cube from the outside with a series of chambers and baffles on the inside. The two principal design configurations for retort incinerators are illustrated in Figures 2-1 and 2-2. In both types of retort incinerators, combustion of the waste begins in the primary, or ignition, chamber. The waste is dried, ignited, and combusted by heat provided by a primary chamber burner as well as by hot chamber walls heated by flue gases. Moisture and volatile components in the waste feed are vaporized and pass, along with combustion gases, out of the primary chamber and through a flame port connecting the primary chamber to the secondary, or mixing, chamber. Secondary air is added through the flame port and is mixed with the volatile components in the secondary chamber. CML.026 2-2 890958 Flame Port Stack Charging Secondary Door Air Ports Secondary ��. � �' • Burner Port Mixing Ignition Chamber Chamber 41 Hearth Rrst Underhearth Port Mixing Secondary Chamber Combustion Flame Port Chamber Charging Door �� Hearth Primary Port Sumer P Secondary ' Underhearth Port Cleanout Doors Side View • Source: Reference 3. m Figure 2-1 . Multiple-Chamber Pathological Waste Incinerator o 2-3 890958 Charging Door Ignition Flame Chamber port Secondary Curtain Air Port Wall ltlrt Combustion chamber Gm Cleanout Location of Doors Secondary Clean Out Curtain Port Wall Burner Mixing Doors Chamber Source: Reference 4. 0 Figure 2-2. In-Line Multiple-Chamber Incinerator 2-4 890958 Burners are also fitted to the secondary chamber to maintain adequate temperatures for combustion of the volatile gases. Incinerators designed to burn general hospital waste operate at total excess air levels of up to 300 percent; if only pathological wastes (i .e. , animal and human remains) are combusted, excess air levels near 100 percent are more common.5 For in-line incinerators, combustion gases pass in a straight-through fashion from the primary chamber to the secondary chamber and out of the incinerator with 90 degree flow direction changes only in the vertical direction. The other common configuration for retort incinerators, on the other hand, causes the combustion gases to follow a more 'tortuous" path through the incinerator with 90 degree flow direction changes in both the horizontal and vertical directions. These flow direction changes, as well as contraction and expansion of the combustion gases, enhance turbulent mixing of air and gases.6 In addition, fly ash and other particulate matter drop from the gas stream as a result of the direction and gas velocity changes and collect on chamber floors. Gases exiting the secondary chamber are directed to. the incinerator stack. Retort incinerators are described as "unwieldy" by one source in sizes above 500 lb/hr capacity while in-line incinerators are felt to be most suitable in capacities of 750 lb/hr or greater.7 2.1.2 Controlled Air Incinerators Controlled air incineration has become the most widely used hospital waste incinerator technology over the past 10 to 15 years and now dominates the market for new systems at hospitals and similar medical facilities.8 This technology is also known as 'starved air" incineration, "two-stage" incineration, and 'modular combustion. While there are some similarities in operating principles between retort and controlled-air incinerators, overall equipment design and appearance are quite different, as illustrated in Figure 2-3. The two-stage incinerator shown in Figure 2-3 is capable of 99.9 percent combustion efficiency.9 Like retort incinerators, combustion of waste in controlled air incinerators occurs in two stages. Waste is fed into the primary, or lower, combustion chamber which is operated, as the name implies, with .less than the full amount of air required for combustion. Under these sub-stoichiometric CML.026 2-5 890958 NMI MK OMNMI n El= BIB IS MITI® V—n SIN 'I} RIM IN Sm ■a' 'a wine ger SRI mar MO NM Fll ISMS II MINI SINN IIIIIIMIE EMI A -' —� PS One memo le INS awe e° aloe sr? FIli § VOYd)h$ A ♦ n ao P R stR a M q 1 COMB NM AN ..J ': 0 0 E MI ISII UDE Figure 2-3. Schematic for Controlled Air incinerator 2-6 890958 conditions, the waste is dried, heated, and pyrolized, thereby releasing moisture and volatile components. The non-volatile, combustible portion of the waste is burned in the primary chamber to provide heat while the non-combustible portion accumulates as ash. Depending on the heating value of the waste and its moisture content, additional heat may be provided by auxiliary burners to maintain desired temperatures. Combustion air is added [ to the primary chamber either from below the waste through the floor of the chamber or through the sides of the chamber. The air addition rate is usually 40 to 70 percent of stoichiometric requirements.10 Because of the low air addition rates in the primary chamber, and corresponding low flue gas velocities and turbulence levels, the amount of solids entrained in the gases leaving the primary chamber is minimized. As a result, most controlled air incinerators can meet current State and local particulate matter emission limits without add-on gas cleaning devices. Moisture, volatiles, and combustion gases from the primary chamber flow upward through a connecting section where they are mixed with air prior to entering the secondary, or upper combustion chamber. If the primary chamber gases are sufficiently hot, they will self-ignite when mixed with air. A second burner is located near the entrance to the upper chamber, however, to provide additional heat for ignition of the combustible gases and to maintain a flame in the chamber at all times of operation. Mixing of these gases with air is enhanced by the flow direction changes and contraction/ expansion step which the gases undergo as they pass from the lower to upper chambers. The air injection rate in the secondary chamber is generally between 100 and 140 percent of total stoichiometric requirements (based on the waste feed) .11 Thus, the total air added to both chambers can vary between 140 and 210 percent of stoichiometric requirements (i .e., between 40 and 110 percent excess air) . The secondary chamber burner is located near the entrance to this chamber to maximize the residence time of gases at high temperatures in this chamber. Bulk average gas residence times in the secondary chamber typically range from 0.25 to 2.0 second. Design exit gas temperatures generally range from 1400 to 2000°F.12 Natural gas or distillate oil are the normal fuels used for both primary and secondary chamber burners. Temperatures in the primary and secondary chambers are monitored by CML.026 2-7 890958 thermocouples and controlled automatically by modulating the air flow to each chamber. Thermocouples are normally located near the exits of these chambers. In the primary (air-starved) chamber, combustion air flow is kept substoichimetric to release volatiles and to keep the gas velocities low to prevent particulates from going out through the secondary combustion chamber. In the secondary combustion chamber, air is generally increased to burn the volatile organics and to create extra turbulence to get mixing between the air and volatiles for proper combustion efficiencies. The logic for this control scheme is illustrated in Figure 2-4. Flue gases exiting the secondary chamber are sent either directly to a stack, to air pollution control equipment (if required), or to a waste heat recovery boiler. Both the primary and secondary chambers are usually lined with refractory material . One manufacturer, however, offers a membrane water wall in the primary chamber. Most chambers are cylindrical ; however, some are rectangular. Smaller units (i.e., with waste feed capacities less than 500 lb/hr) are usually vertically oriented with both chambers in a single casing. Larger units generally include two separate horizontal cylinders located one above the other.13 Some manufacturers offer a third chamber for final air addition to the combustible gases and a fourth chamber for gas conditioning (i.e., gas cooling and condensation of vapors) to minimize effects on downstream heat recovery equipment or air pollution control equipment.14 Waste feed capacities for controlled air incinerators range from about 75 to .6500 lb/hr of Type 0 waste (at '8500 Btu/lb). Capacities for lower heat content wastes may be higher since feed capacities are limited by primary chamber heat release rates. Heat release rates for controlled air incinerators typically range from about 15,000 to 25,000 Btu/hr-ft3 16 2.1.3 $otary Kiln Incinerators Like other incinerator types, rotary kiln incineration consists of a primary chamber in which waste is heated and volatilized and a secondary chamber in which combustion of the volatile fraction is completed. In this case, however, the primary chamber consists of a horizontal , rotating kiln. The kiln is inclined slightly so that the waste material migrates from the waste charging end to the ash discharge end as the kiln rotates. The waste migration, or throughput, rate is controlled by the rate of rotation and the CML.026 2-8 890958 1 rw•fle TB1•q•flM•••C'"""WWII •.•• ar a fir• ar. P >14istiN Sal • 1• r• -M • •• • •• 441 a• a• a�rr• Source: Reference 15. Figure 2-4. Adiabatic Temperature Versus Excess Air for a Controlled Air Incinerator 2-9 890958 angle of incline, or rake, of the kiln. Air is injected into the primary chamber and mixes with the waste as it rotates through the kiln. A primary chamber burner is generally present for heat-up purposes and to maintain desired temperatures. Both the primary and secondary chambers are usually lined with refractory brick, as shown in the schematic drawing in Figure 2-5. Volatiles and combustion gases from the primary chamber pass to the secondary chamber where combustion is completed by the addition of additional air and the high temperatures maintained by a second burner. Like other incinerators, the secondary chamber is operated at above- stoichiometric conditions. Due to the turbulent motion of the waste in the lower primary chamber, particle entrainment in the flue gases is higher for rotary kiln incinerators than for the other two chamber incinerator designs previously discussed. As a result, rotary kiln incinerators generally require stack gas clean-up to meet applicable particulate matter and/or opacity limits.17 2.2 WASTE FEED AND ASH HANDLING SYSTEMS Feed systems for hospital waste incinerators range from manually operated charging doors to fully automatic systems. Ash removal systems also range between periodic manual removal of ash by operators to continuous automated quench and removal systems. In general , automated systems are prevalent among large continuously-operated incinerators while manual systems are employed on smaller incinerators or those which operate on an intermittent basis. Waste feed and ash removal systems are discussed below for each of the major incinerator design types. For retort incinerators, waste loading is almost always accomplished manually by means of a charging door on the incinerator. The charging door is attached to the primary chamber and may be located either at the end farthest away from the flame port (for burning general wastes) or on the side (for units handling pathological wastes such as large animals or cadavers). As much as 10 percent of the total air supplied to retort units is drawn through these charging doors.19 Ash removal from retort units is accomplished manually with a rake and shovel at the completion of the incinerator cool-down period. Typical operation for a retort incinerator CML.026 2-10 890938 Secondary Combustion Chamber Charging Hopper \••0 t Ash Rotary Kiln Discharge Source: Reference 18 Figure 2-5. Refractory Rotary Kiln System 2-11 890958 calls for incinerator heat up and waste charging at the end of the operating day, waste combustion and burnout by morning, and cool-down and ash cleanout during the following day.20 Controlled-air incinerators may be equipped with either manual or mechanical loading devices. For units with capacities less than 200 lb/hr, manual loading through a charging door in the primary chamber is typically the only option. Mechanical loaders, on the other hand, are standard features for incinerators with capacities above 500 lb/hr waste. For units between these size ranges, mechanical feed loaders are usually available as • an option.21 Most mechanical loader designs currently offered employ a hopper and ram assembly, as illustrated in Figure 2-6. In this system, waste is loaded into a charging hopper and the hopper cover is closed. The fire door isolating the hopper from the incinerator opens and a ram comes forward to push the waste into the front section of the incinerator. After reaching the end of its travel ,. the ram reverses and retracts to the point where it just clears the fire door. The fire door closes and the ram retracts to its starting position. These operations are normally controlled by an automatic control panel . For smaller incinerators, waste loading into the charging hopper is usually accomplished manually, bag by bag. Larger systems frequently use such waste loading devices as car dumpers, conveyors, skid-steer tractors, or pneumatic systems.23 In addition to improving personnel and fire safety, mechanical loaders • limit the amount of ambient air which can leak into the incinerator during waste feeding operations. This is important for controlled air incinerators since excess air in-leakage can cause lower temperatures, incomplete combustion, and smoking at the stack. Mechanical loaders also permit the feeding of smaller waste batches at more frequent, regular intervals. As the intervals become shorter, this feeding procedure approximates continuous or steady-state operation and helps to dampen fluctuations in combustion conditions.24 Ash removal techniques for controlled air incinerators also range from manual to mechanical systems. For smaller units below about 500 lb/hr capacity (and units constructed before the mid-1970s), operators must rake and shovel ash from the primary combustion chamber into disposal containers. • CML.026 2-12 890958 MIR ► 9 WASTE LOADED IWO HOPPER operatingSTEP, E�t,T'r. cl eanout mmE DOOR OPENS STEP or iw COMES FORWARD 0lb/hr, I oically STEPS Lommilims Sur PEVEnsEsma EM ME DOOR i )r units inn 4 able as "RE°°°"CLOSES ya em, ! w�RETURNS mSTART 1. The :omes After point I tro .d ig into *ger •eyors, aders ring -ators he As nuous Source: Reference 22 rom ke ers. Figure 2-6. Schematic and Example of a Mechanical Loading System 2-13 890958 for larger systems, mechanical ash removal may be accomplished by extension of the waste charging ram, augmented by internal transfer rams. The positive displacement action of the rams pushes the ash along the bottom of the primary chamber until it reaches a drop chute. Mother mechanical system offered by one manufacturer uses a 'pulsed hearth' whereby ash is moved across the chamber floor by pulsations created by end-mounted air cushions.25 After falling through the drop chute, ash either falls into a drop cart positioned within an air-sealed enclosure or into a water quench trough. The drop cart is removed manually, generally after spraying the ash with water for dust suppression. In the water trough system, quenched ash is removed either by a drag conveyor or a backhoe trolley system.26 When estimating air emissions for controlled air incinerators with manual ash removal , it is important to recognize that operating, and hence emission, rates will vary over time. A typical operating cycle for such a unit is given by:27 Operation Duration . Ash-clean-out 15-30 minutes Preheat 15-60 minutes Waste loading 12-14 hours Burn-down 2-4 hours Cool-down 5-8 hours The waste loading period of 12 to 14 hours per operating day is a maximum value for units with manual ash removal ; based on observations at one incinerator a more typical value might be 5 to 6 hours since this corresponds to waste incineration during one shift per day.28 On the other hand, large incinerators with continuous mechanical ash removal systems may operate on an around-the-clock basis. Since rotary kiln systems operate in a continuous mode, the waste feed system and ash removal system which service these incinerators must also be of a continuous or semi-continuous type.29 A charging hopper and ram system is commonly used to load waste into the kiln. After travelling through the kiln, ash is discharged on a continuous basis either into an ash cart or water quench system. Both this feed system and ash removal system are described above for controlled air incinerators. CML.026 2-14 890958 2.3 WASTE HEAT RECOVERY Waste heat recovery operations are generally not considered for excess air incinerators due to the smaller gas flow rates, lower temperatures, higher particulate matter loadings, and intermittent operations that characterize these systems. For controlled air and rotary kiln incinerators, however, the relatively higher stack gas temperatures and flow rates can make heat recovery economically attractive in cases where steam or hot water generation rates can be matched with the needs of the hospital. For most systems, heat is recovered by passing hot gases through a waste heat boiler to generate steam or hot water. Boiler equipment can range from a spool piece with heat exchange coil inserted in the stack to a single-drum D-type watertube waste heat boiler. Most manufacturers, however, use conventional firetube boilers because they are low in cost and simple to operate.30 Options for-these boilers include supplemental firing of oil or natural gas and automatic soot-blowing systems. Outlet temperatures from waste heat boilers are generally limited to about 400°F by stack gas dew point considerations. As mentioned above, one manufacturer also offers a waterwall membrane in the primary chamber to enhance heat recovery. Other methods to improve overall system efficiency in controlled air incinerators and, thereby, to reduce the need for expensive auxiliary fuels, are modulating burners and air preheating.31 EPA-sponsored testing programs of controlled air incinerators equipped with these types of systems have shown that heat recovery efficiencies are typically limited to about 50 to 60 percent of the theoretical maximum.32 CM1.026 2-15 890958 2.4 REFERENCES 1. Radian Corporation. Municipal Waste Combustion Studv, Data Gathering phase. EPA Contract No. 68-02-3889. November 1986. p. I-11. 2. Brunner, C. R. 'Biomedical Waste Incineration.' Presented at the 80th Annual Meeting of the Air Pollution Control Association. New York, New York. June 21-26, 1987. p. 10. 3. Block, S. S. and J. C. Netherton. Disinfection. Sterilization, and Preservation. Second Edition. 1977. p. 729. 4. Reference 3. p. 727. 5. Reference 3. p. 730. 6. Reference 3. p. 728. 7. Reference, 3. p. 730. 8. Doucet, 1. G. Controlled Air Incineration Design. Procurement, and Operational Considerations. Prepared for the American Society of Hospital Engineering. Technical Document No. 55872. January 1986. p. 1. 9. Lauber, J. G. Mew Perspectives on Toxic Emissions form Hospital jncinerators. Presented at the N. Y. State Legislative Commission on Solid Waste Management Conference on Solid Waste Management and Materials Policy. New York, New York. February 12, 1987. p. 11. 10. Reference 10, Appendix. 11. Reference 2, p. 11. 12. Reference 8, p. 5. 13. Basic, J. N. 'Multiple Stage Combustion Design Can Minimize Air Pollution Problems.' Presented at the 80th Annual Meeting of the Air Pollution Control Association. New York, New York. June 21-26, 1987. p. 3. 14. Reference 2. p. 12. 15. Reference 2. p. 16. 16. Reference 8. p. 14. 17. Reference 2. p 12. CML.026 2-16 890958 18. Reference 15. 19. Reference 3. p. 730. 20. Reference 2. p. 10. 21. Reference 8. p. 6. 22. Consumat Systems Inc. Consumat Waste Handling System Technical Data Sheet. Richmond, Virginia. Received by Radian Corporation in June 1987. p. 1. 23. Reference 8. p. 7. 24. Reference 8. p. 6. 25. Reference 8. p. 8. 26. Reference 8. p. 8. 27. Reference 8. p. 14. 28. Allen, R. J, 6. R. Brenniman, and C. Darling. 'Air Pollution Emissions from the Incineration of Hospital Wastes.' Air Pollution Control Association Journal , Volume 36, No. 7, July 1986. pgs. 829-831. 29. Reference 2. -p. 12. 30. Reference 8. p. 9. 31. Reference 8. p. 9. 32. Reference 8. p. 9. CML.f26 2-17 890958 • 3.0 AIR EMISSIONS/FACTORS FOR HOSPITAL WASTE INCINERATORS Many sources of information were used to collect available hospital incinerator emissions data. A survey of pertinent literature was performed and contacts were made within EPA, State and local government organizations, trade organizations, and incinerator vendors. Table 3-1 contains a list of pollutants covered by this study. The compounds shown here are those for which emissions data could be located for hospital incinerators. As expected, data for some pollutants were plentiful , while few data were found for others. One large data gap in the current hospital waste incinerator emissions data base is for lower molecular weight organic compounds. In addition, emission data located were primarily for larger, controlled air incinerators; few data were located for the smaller, retort-type incinerators which comprise a large portion of the existing population by number. This section first contains brief descriptions of formation mechanisms for pollutants for which data were found. Where applicable, information on formation mechanisms for these compounds has been taken from the municipal solid waste (MSW) literature. Next, the emissions test data are presented along with other data which were located as part of the study. A discussion relating emissions data to design and operating factors follows. Finally, the emissions factors developed for each pollutant are presented. 3.1 FORMATION MECHANISMS • 3.1.1 Acid Gases The acid gases considered in this study were hydrogen chloride, sulfur dioxide, and nitrogen oxides. 3.1.1.1 Hydrogen Chloride. Based on thermodynamic considerations, chlorine which is chemically bound within the hospital waste in the form of polyvinyl chloride (PVC) or other compounds will be predominately converted to hydrogen chloride (HC1), assuming there is hydrogen available to react with the chlorine. However, the rate of HC1 formation is inhibited and subsequently reversed when too much excess air is added to the combustion chambers.1 Too much excess air can lower the combustion temperature by dilution and increase the oxygen content, thereby promoting greater free CML.026 3-1 890958 f • S. 61 a+ a+ 61 A a r X N 61 O S. M C 61 IV O N a r a C 4.1 o = O C 01 61 ♦+ .0 L = I. i 4./ i a u a a o v W U fa H 41 4.1 .5 C W N a, v o 0 o L. O 0 re W 9 a C N C N V i C' W C L 3 S. >1 = 4.1a COI S. Cl a a 61 5C 61 d i C 641 ?1 .J J w C - ra - 2 - N w - L X61 D S. ♦+ O U C ♦+ 61 S. 61 O .-• .Op y Op 61 C 6,1 C 61 L .C SG E N N C C - - A F. V Irf a >, t a t A ELI N >, 0. O. U a+ US. m =1r3 a a L O L O S. N W W L 0. 1.- i r r H V — N i— U L a N '. CN X X -L a C � £O O • 61 U E 1 N N r 3 rE C V 0 N E O C a . r+ 41 U Ha C L. N a a a J i..i CML.026 3-2 890959 chlorine exhaust concentrations. Considering the high hydrogen content of hospital waste owing to its high paper, plastics, and moisture content, there should be a ready supply of hydrogen available in most cases to promote HC1 formation. Swedish studies have found that 60 to 65 percent of the fuel-bound chlorine in NSW is converted to HC1 .2 There is no apparent thermodynamic reason for the less than full conversion. HC1 has also been shown by other studies to be the predominate chlorine product at high temperatures.3 3.1.1.2 Sulfur Dioxide. Sulfur, which is chemically bound within the materials making up 'hospital waste, is oxidized during the combustion process to form S02. The rate of SO2 emissions is, therefore, directly proportional to the sulfur content of the waste. Some SO2 removal may take place through reaction of the SO2 with alkaline reagents also present within the waste; however, the amount of removal is expected to be negligible due to the high HC1 content of the flue gas. Because it is a stronger acid than 502, HC1 will react more quickly with available alkaline compounds than 502. The high HC1 content of flue gases will likely tie-up the alkaline compounds • before they have a chance to react with $02. 3.1.1.3 Nitrogen Oxides. Nitrogen oxides, or NOx, represent the mixture of NO and NO2. In combustion systems, predominantly NO is produced due to kinetic limitations in the oxidation of NO to NO2. NOx is formed by one of two general mechanisms. 'Thermal NOx' is the result of the reaction between molecular nitrogen and molecular oxygen, both of which enter the combustion zone in the combustion air. 'Fuel NOx' results from the • oxidation of nitrogen which enters the combustion zone chemically bound within the waste material . Although the detailed mechanism of thermal NOx formation is not well understood, it is widely accepted that the thermal fixation in the combustion zone is described by the Zeldovich equations:4 N2 + 0 ex= NO + N N + 02 * NO + 0 CML.026 3-3 890958 t The first reaction is the rate limiting step and is strongly endothermic due to the requirement of breaking the N2 triple bond. It is the high endothermicity of this process which has led to the term 'thermal NOx.' The reaction rates of these equations are highly dependent on both the mixture stoichiometric ratio (i.e., the molecular equivalent air-to-fuel ratio, with rich and lean describing the fuel amount) and the flame temperature. The maximum NOx formation levels occur at slightly lean fuel mixture ratios due to the excess availability of oxygen for reaction within the hot flame zone. A rapid decrease in NOx formation is seen for ratios which are slightly higher or lower than this. The rate of thermal NOx formation is extremely sensitive to the flame temperature, dropping almost an order of magnitude with every 100°C drop in flame temperature. The mechanisms by which nitrogen compounds (primarily organic) contained in liquid and solid fuels evolve and react to form NOx are much more complex than the Zeldovich model , and the empirical data are less conclusive. The impact of temperature and fuel nitrogen on NOx emissions for excess air conditions is shown in Figure 3-1. The figure indicates that thermal NOx formation is extremely sensitive to temperature, but fuel NOx formation is less sensitive. 3.1.2 Particulate Matter Particulate matter (PM) is emitted as a result of incomplete combustion and by the entrainment of noncombustibles in the flue gas stream. PM may exist as a solid or an aerosol , and may contain heavy metals or polycyclic organics. Depending on the method used to measure the PM in the flue gas, lower boiling point volatile compounds (i.e., boiling point below 100°C) may or may not be included in the measurement. There are three general sources of PM6: o inorganic substances contained in the waste feed that are carried into the flue gas from the combustion process, o organometallic substances formed by the reactions of precursors in the waste feed, and o uncombusted fuel molecules. • CML.026 3-4 890958 T(°F) 3140 2813 2509 2310 2112 1941 10,000 r MAX 1000 - PECT• `�0 A0MAC _ 100 - 0.SZ FUEL N - F. s 10 302 EXCESS AIR - r - 0.5 SEC. 1.0 - THERMAL NO - FUEL N 0. 1 , 0.45 0.50 0.55 0.60 0.65 0.70 103/T cr1) Source: Reference 5 Figure 3-1 . Impact of Temperature and Fuel Nitrogen on NOx Emissions for Excess Air Conditions 3-5 890959 Inorganic matter is not destroyed during combustion; most of this material leaves the incinerator as ash. Some, however, becomes entrained in the stack gas as PM. Organometallic compounds present in the waste stream which is being incinerated can be volatilized and oxidized under the high temperatures and oxidizing conditions in the incinerator. As a result inorganic oxides or salts of metals can be formed. Elemental analysis of flyash from MSW incinerators has shown that particulate emissions are largely inorganic in nature and that they are from one-third to one-half soluble in water. The water soluble phase is principally chloride and sulfate salts of Na, P, Ca, Zn, and NH4+. The insoluble phase is comprised of oxides, silica, and phosphate salts of Al , Si , Ca, Pb, Zn, and Fe along with some insoluble carbon compounds.7 To the extent that a particular hospital waste is similar to municipal waste, the resulting ash might be expected to be similar. (See Section 1.2 for discussion of hospital waste composition and categorization.) The fuel molecules themselves can also contribute significantly to PM formation. It is known that pyrolitic reactions can lead to the formation of large organic molecules. Inorganics, which may act as nucleation sites, may then further induce growth. The result can then be organic particles with inorganic cores.8 In general , good combustion conditions which depend on residence time, temperature, and turbulence, lead to lower PM emissions. As the residence time increases, particle size and the mass of PM tend to decrease. Smaller particle sizes and lower PM emissions are also associated with higher temperatures since, at higher temperatures, oxidation rates are increased so that more of the combustible PM is oxidized to gaseous products. 3.1.3 Trace Metals • The amount of trace metals in the flue gas is directly related to the quantity of trace metals contained in the incinerator waste. Some of the trace metal sources in the waste feed include surgical blades, foil wrappers, plastics, and printing inks. Plastic objects made of PVC contain cadmium heat stabilizing compounds. In addition, cadmium, chromium, and lead may also be found in inks and paints. CML.026 3-6 • 890958 Some metals are selectively deposited on the smaller particulate sizes which are emitted. This is known as fine-particle enrichment. Although such data were not found for hospital incinerators, metals generally thought to exhibit fine-particle enrichment are As, Cd, Cr, Mn, Ni, No, Pb, Sb, Se, V, and Zn.9 Results of one study performed at a MSW facility indicate that trace metals are found predominately in the respirable particulate fraction, even when the bulk of the particulate matter emissions are in the nonrespirable fraction.10 Studies conducted by Trichon, et. al . have shown that certain metals when exposed to a reducing atmosphere can be converted to sub-oxides or even pure metal vapors. The end product of these overall reactions can result in particulate distributions less than 0.1 microns.11 There are three general factors affecting enrichment of trace metals on fine particulate matter12: o particle size, o number of particles, and o flue gas temperatures. The influence of particle size on trace metal enrichment of fine particles is thought to be due to specific surface area effects (i.e., the ratio of particle surface area to mass). Particles with large specific surface areas show more enrichment since there is more surface area for condensation per unit mass of PM. The influence of the number of particles is simply due to the increased probability of contact associated with higher particle population. There is some evidence that less enrichment occurs at higher flue gas temperatures.13 Higher temperatures are thought to lead to increased activity levels which, in turn, make the metals less likely to condense and bond with PM. Mercury, due to its high vapor pressure, does not show significant particle enrichment; rather it is thought to leave largely in the vapor form due to high typical exit gas temperatures. For example, the results of one study performed at a MSW facility indicated that less than 25 percent of the mercury emissions were found to be in the particulate phase of the stack gas.14 3.1.4 Organic Emissions Figure 3-2 presents a schematic of the processes which are involved during hospital waste combustion in a two-stage incinerator. After startup, CML.026 3-7 890958 W. I- . a 0 N � at O W cid N u m 6 E = Ii• ei f t � V C U a _ Ms a mm • • �+ ~ � t CO • 0 «m j . s o N u go .. W a _ \ I P_ co LE 1 II I 05 • 0 d5 CML.026 3-8 890958 the hospital waste is heated by the burning gases being combusted in the primary chamber and by the natural gas or oil burner operating in that chamber. It is the burning of volatile matter above the waste bed which provides the heat which continues the pyrolysis and volatile matter evolution from the waste. The amount of radiant heat transfer to the waste is strongly dependent on the local flame temperature of the compounds being combusted; the flame temperature, in turn, is a function of moisture content, volatile matter heating value, and the local air stoichiometry. Not all the volatile matter is combusted in the primary chamber. Combustion gases are swept from the primary chamber to the secondary chamber where volatile matter combustion continues, augmented by the heat generated by a second fossil fuel burner. The volatile matter combustion process is controlled by chemical kinetics and proceeds through complex reactions involving 0, H, and OH radicals. The kinetics of these processes are strongly temperature dependent. An efficient burning process will result in a high degree of conversion of volatile organics to CO2 and H20. Failure to achieve efficient combustion can result in high emission rates of unreacted or partially reacted organics. Generally, insufficient combustion can occur as a result of charging the incinerator with waste materials in a batch mode. A study has shown that when waste materials are initially charged into the incinerator, the oxygen level in the incinerator is momentarily reduced, resulting in higher emission rates of unburned gaseous and particulate hydrocarbons.15 The unreacted or partially reacted combustion products discussed in this report include the chlorinated isomers of dibenzo-p-dioxin (CDD) and dibenzofuran (CDF), lower molecular weight organic compounds for which emissions data were available, and carbon monoxide (CO). A brief description of the formation mechanism and factors which influence the formation of these compounds is presented in the following subsections. Other important classes (e.g. , PICs, BaP, PCBs, PAH, POM) are not included due to lack of emissions data. 3.1.4.1 Dioxins and Furans. Many factors are believed to be involved in the formation of CDDs and CDFs and many different theories exist CML.026 3-9 890958 concerning their formation. The best supported theories are illustrated in Figure 3-3.16 The first theory shown involves the breakthrough of unburned CDD/CDF present in the feed.17 A few measurements of MSW feed streams have indicated the presence of trace quantities of CDO/CDF in the refuse feed. I� No such measurements have been made for hospital waste streams, but some potential for CDD/CDF in the feed may exist due to similarities in the wastes. The second mechanism shown in Figure 3-3 involves the more plausible combination of precursor species which have structures similar to the dioxins and furans to form the CDD/CDF compounds. Such a reaction would involve the combination of chlorophenols or polychlorinated biphenyls to form CDO/CDF. These precursors can be produced by pyrolysis in oxygen-starved zones, such as those which exist in multichamber incinerators.18 The potential for PVC-bearing wastes, a typical component of hospital waste, to form precursors during combustion has been studied by several researchers.19,20 The third mechanism shown in Figure 3-3 involves the synthesis of CDD/CDF from a variety of organics and a chlorine donor.21 The simplest mechanisms here involve the combination of those species which are structurally related. Many plausible combustion intermediates can also be proposed which lead to precursors and eventually to CDD/CDFs. Analysis of intermediates formed during the combustion of complex fuels such as coal or wood indicate measureable yields of unchlorinated dioxin and furan species. These compounds could become chlorinated in systems such as hospital waste incinerators where high concentrations of molecular chlorine exist in the combustion zone. The final mechanism presented in Figure 3-3 Involves catalyzed reactions on fly ash particles at low temperatures. In research sponsored by the Ontario Ministry of Environment, formation of CDDs/CDFs were observed when the thermolysis products of PVC combusted in air were heated to 300°C in the presence of clean fly ash.22 There is a growing consensus that the formation of dioxins and furans in combustion furnaces requires excess air.23 Excess air combustion leads CML.026 3-10 890958 I. DIOXIN IN REFUSE Cl �,0 Cl 1f O O Combustion UnDO/CDF 0 -� bust -� CDD/CDF Cl 0 Cl II. FORMATION FROM RELATED CHLORINATED PRECURSORS Cl OH Cl Cl 0 Cl + 0 -1.- 0 OO O + H2 C1 OH Cl Cl 0 Cl Chlorophenol Dioxin 0 a O O O ..... 4 ;:i.„.. C O O 1 Cl Cl Cl Cl PCB Furan III. FORMATION FROM ORGANICS AND CHLORINE DONOR PVC Chlorine donor + _� COD/CDF Lignin NaCI , HC1 , C12 IV. SOLID PHASE FLY ASH REACTION Precursor COD FlFl Ash + Cl Donor lower Ash temp Source: Reference 16 Figure 3-3. Hypothetical Mechanisms of CDD/CDF Formation Chemistry 3-11 890958 • to lower combustion temperatures which favor in-situ chlorine formation over HC1 formation. The additional presence of chlorine is then believed to promote the formation of dioxins and furans. CDOs and CDFs may exist in both the vapor phase and as fine particulate in hospital waste incinerator emissions. They may be split between phases with as much as 80 percent in the vapor phase.24 At temperatures below 300°F, they condense onto the fine particulate. Furthermore, based on a national study of combustion sources, a range of 0.05 to 135 ppb of PCDO and 0.07 to 3,734 ppb of PCDF has been detected in the bottom and fly ashes of, four hospital incinerators.25 3.1.4.2 Low Molecular Weight Organic Compounds. Low molecular weight organic compounds (LC) are products of incomplete combustion of the volatiles which are evolved from the waste. They may be present due to some of the same mechanisms previously discussed above for dioxins and furans; that is, they may be compounds which were present in the fuel , combinations of precursors, or the dioxin and furan precursors themselves. LCs are produced when the combustion conditions are other than optimal . In general , the optimum combustion conditions can be characterized by the three T's; time, temperature, and turbulence. The longer the time, the higher the temperature, and the greater the degree of turbulence in the zone where the organics are combusted, the better the combustion and the lower the LC emissions will be. 3.1.4.3 Carbon Monoxide. Carbon monoxide (CO) is also a product of incomplete combustion. As shown, CO is one chemical reaction away from being CO2 which represents the end product of combustion and this signifies complete combustion. Its presence can also be related to the time, temperature, and turbulence conditions which exist above the region in which the LCs are vaporized. 3.2 EMISSIONS TEST DATA Two different categories of emissions test data were collected during this study: 1) data which had been reviewed and were considered final and 2) preliminary data which had not received final review and inspection. Both categories of data are reported in this section for the sake of completeness but only the final data are used to calculate typical emission CML.026 3-12 890958 factors. Final emissions data were acquired from seven comprehensive emissions tests of hospital incineration units.26-29,40-42 In addition, results of several less detailed tests at hospital incinerator units were located through the literature. A description of each of the seven units for which comprehensive information was obtained and the operating conditions recorded during the emissions tests are presented in Table 3-2. As shown, most of the units are large incinerators near the upper end of the size range for hospital incinerators. The smallest unit for which comprehensive test results were located is an 175 lb/hour unit and the largest was a 2000 lb/hr unit. Over the period of the comprehensive emissions tests, four of the units operated at 82 to 99 percent of feed rate design capacity. The remaining three incinerator feed rates ranged from 396 to 1,493 lb/hr during the test; maximum design capacities for these incinerators are not known. All of the units shown in Table 3-2 are starved air incinerators with two combustion chambers. The operating temperature of the secondary combustion chamber is slightly lower for the Illinois hospital incinerator than for the other units. It should be noted that the secondary chamber . temperature data for the Illinois incinerator include both start-up and shutdown periods. Thus, the lower end of this range most likely corresponds to these transient operating conditions. Three of the test reports did not include incinerator design specifications. The stack parameters for all of the units are within what was determined to be the normal design range (see Section 6.0) . Unfortunately, little information is available regarding the operating conditions of the Illinois, Queen of the Valley, Swedish-American, and University of Michigan • units. No information was available regarding the characteristics of the hospital wastes which were incinerated by any of these units. In addition, sufficient flue gas composition data were not available to normalize emission values to a single 02 or CO2 level . No emissions data were located for the smaller retort-type incinerators which comprise a large portion of the total population by number. It is important to remember that the emission data and factors discussed in this CML.026 3-13 890958 I C.IC IOC 00 O<ccc I fa ��O O 1n O.......•••........% MI 222W2 0101 102222 N A r 4.) 41 0 .•I...I a 0 0 I I 1— r N O.H I0nc0 VI Iasi O Pf N _ la-- ..- ..I.ti Z O .r in a 4 .1 W .••rm w10 00 03 0OM0O 00 .N.IO CT01 • O F ..n .0 ••• A I�N 01 '!� PfOP . N 10 . 2 ^J O. N 1j IQ•••• .n•r A C LLI VI CI 0 W I0 2 td t..i j CC 0. O Z. C CC u i I. tu a a 4.• ad L I+0 CO01 Co P0f1100 •+I • W CV r CO 1•••• 100 O Fla At 01 W •01 O 10 .•I CV CV a i RP col c - artV W^ O �0. Isi I IS OS �� 2 . Oa. H g O Lc O. .r N V •N CIO N 00 NOM C0 P1 Pf 0 C L.W 0 C CO 0 0 Pf.•I at.I . C N+` 6J d el COtpO /•1 A. 01 ` ai. r • 00^ +.CU N ff{ 2 N U C W la O O In u= e ^'^ 0 J W I H .• a .M• W a ^. O W L L v a a • e lot 7 L vvv 4..CV olf •••• • a w A aas 10 N 10 d d W N�� C 1y .y 4) N 4\a C O Z .J CCU WOW 4+ 0a A-I'm > 10 A 0D O1 ' CO •C Iv s- —.— N N N N N L C to L H tJ >1 ■ 7 4.1 c c 0 WW O S. A 4+ • >1 LOH 0,1W WW d 41 • •4+ 01>% '0 L Ill 4+ 41 • L • L.AA L •CCsC O. 0L1NN ~yN ~ CCi C O W C C.+ 41 4) 0 i C.- 01RIC Al r y .* Ea i- ^r 0 C d d • � d.Oy.• Jr L L • V 6/r ••.- p Y- Y- w Y- C 41 V C.. 6Sa yl-C��Oi • d WWW C a A.0 u 7 CML.026 3-14 890958 0001C CO 41 en eDOO en N 02012 a men el e•1.• To— N 4+ 1n sit Co 01 en eF r r C ••r •.r n•• to O 0. I !1 N . EC H .S. C: LO S. CZ N .0 T C W W N 6 L L. C 1••• > OS W ell o T T C W W U C 4 ..JJ = — T. N Of pH CO W W • O Iv= C C o N .J. a.1 Gen � uu CC •..•001.•'0 H1 W r A • 1••••PI.. Cn a o n .eV N L N = E en•'••••0. e0.•eO CC of W •J L N A —.• LW 1 N 14=O o 0 - Y1 = U V T 0 VC 0. WI CC C C— 1 C «• W 1••• C �� d4 S C 4=+$6 C CC ICI C CC CC In CZ) ou9lV en Co «_ ou a Zz 01 zz C*J 0�"C a S t0 a .• .- C 0 N N Ci a =.— C •.. C7 RI N M. W C W r •~. LL COI r•r. 0 L L v VI d 43) 'Si .0 �. L N L 0 W a••. 44 W W't LAIN O W N.-. N 01 4+N N 04 N Lvf.J\ •r 1 W N NO E.C N N a. 0 0 en S CCJ ■ NC../ nW+ WCw— > O ••. N O/•C W■E L•rvvv N f a itt -Wi O a�W O ~V L •I 4=1 W !1 L W N W W W CO 4e W W4+ O1>, N Smelt) 4+ W L C . U U U N WIiC CL9 NLNT417 H C C C 16- L alb L .- CC S W L U ell 4+ W W W W Cr• W 4+ EO S3OEN w L L L C ..- 010C NT U >rC E Or NT 0 Cl W C T Cl. 0 T L L W U W r W T O e/- se. W U 10 N4+ U W0.COI NHW>0 • W W W C =CC••• 0. N Z W W C 89®958 CML.026 3-15 section are based on the performance of relatively large controlled air incinerators. More data are needed to accurately characterize emissions from smaller, retort incinerators. 3.2.1 Acid Gases }ivdroaen Chloride. Table 3-3 contains a .summary of the hydrogen chloride (HC1) emissions data which were gathered during this study. Emissions factors are also shown for each of the units. The HC1 emissions results of Table 3-3 include the units described in Table 3-2 as well as units in the United States and Canada for which information was obtained from a survey article.30 There is no apparent correlation between the unit feed rates and the HC1 emissions. This is understandable because, as previously stated, the level of HC1 emissions should be directly related to the percentage of chlorine-containing compounds in the waste fed to the unit. Unfortunately, no information was given regarding the chemical composition of the wastes being. burned. Two of the units for which emissions data are available have scrubbers which are used for acid gas control . These units have the lowest emissions rates of those shown. The type of wet scrubbers used was not identified in Reference 30. Sulfur Dioxide and Nitrogen Oxides. Table 3-4 summarizes the emissions data and calculated emission factors for SO2 and NO . As can be seen, there x are limited data available for these compounds. The only two sources found were two test reports from the state of California. On a concentration basis, the emission rates for the pollutants in . Table 3-4 are relatively low. For the highest SO2 concentration, 50 ppmv, an equivalent SO2 emissions rate of 0.15 lb/million Btu would be expected, assuming a mean heat content of 10,000 Btu/lb for hospital waste.. A mean heating value of 5,000 Btu/lb would correspond to an SO2 emissions rate of 0.3 lb/million Btu. The corresponding maximum NOx emissions rates (based on the 270 ppmv concentration) are 0.4 and 0.8 lb/million Btu for heat contents of 10,000 and 5,000 Btu/lb, respectively. 3.2.2 Particulate Matter A great deal of PM emissions data have been collected for controlled air hospital waste incinerators. Some of the most readily available data are shown in Table 3-5. Much of this data has been collected because CML.026 3-16 890938. TABLE 3-3. DATA/FACTORS FOR HYDROGEN CHLORIDE EMISSIONS FROM HOSPITAL WASTE INCINERATORS HC1 Emissions Add On Incinerator Concentra- Factor Control Device/ Feed Rate tion (lb/ton Hospital Heat Recovery (lb/hr) (ppmv) feed) Cedar Sinaia Fabric Filter/Yes 980 High 521.0 16.3 Low 403.0 12.7 Average 462.0 14.5 St. Agnesb None 783 High 926.0 15.5 Low 764.0 12.0 Average 845.0 13.7 Royal Jubileec None 1,930 High 1,520.0 65.7 Low 983.0 42.5 Average 1,252.0 54.1 Illinois Unitd None 500-800 High 1,490.0 10.6e Low 170.0 6.6e Average 550.0 8.6e Queen of the Valleyh NR High 412 445 8.7 Low 374 282 6.4 Average 396 341 7.2 Swedish-Americana NR High 175 174 12 Low 172 172 12.9 Average 174 173 12.5 University • of Michigan.' NR High 1493 928 45.4 Low 644 31 .1 Average 788 87.8 CML.026 3-17 890958 4 TABLE 3-3. DATA/FACTORS FOR HYDROGEN CHLORIDE EMISSIONS FROM HOSPITAL WASTE INCINERATORS (CONTINUED) HC1 Emissions Add On Incinerator Concentra- Factor Control Device/ Feed Rate tion (lb/ton Hospital Heat Recovery (lb/hr) (ppmv) feed) Athabasca None 85 41.0 68.1 Misericordiaf None 740 670.0 63.1 Misericordiaf None 740 687.3 63.1 Royal Alexf None/Yes 1,160 553.0 84.5 Royal Alexf None/Yes 1,200 562.0 79.6 Foothills None 2,500 702.0 "72.8 Lethbridge Gen.f Wet Scrubber/Yes 1,060 44.6 5.9g Univ. of Albertaf Wet Scrubber/Yes 1,400 64.7 0.79 Univ. of Albertaf Wet Scrubber/Yes 1,400 25.4 4.49 Bonnyvillef None 130 62..2 16.5 Willingdonf None 130 308.0 24.3 Lacombe None 150 234.5 14.6 Ft. McMurrayf None 265 700.0 48.6 Ontario Hospitalsk None 408 NR 17.4 St. Michaelsk None 465 2,095.0 99.4 Queen Elizabeth IIk None 575 115.0 22.3 Queen Elizabeth IIk None 700 287.0 19. 1 Queen Elizabeth IIk None 700 378.0 25.3 cNL.026 3-18 890958 TABLE 3-3. DATA/FACTORS FOR HYDROGEN CHLORIDE EMISSIONS FROM HOSPITAL WASTE INCINERATORS (CONTINUED) HC1 Emissions Add On Incinerator Concentra- Factor Control Device/ Feed Rate tion (lb/ton Hospital Heat Recovery (lb/hr) (ppmv) feed) Mediwastel None 1,200 NR 9.5 Shore Memorial° None 650 NR 9.2 Nyack Hospital" None NR NR 2.9 aReference 26. bReference 27. cReference 28. dReference 29. eBased on emissions factors presented in Reference 29. (Reference 30. 9Wet scrubber may have reduced HC1 emisssions. hReference 40. 'Reference 41. 'Reference 42. kReference 43. 1Reference 46. °Reference 47. "Reference 48. NR - Not Recorded CML.026 3-19 890958 - ll TABLE 3-4. DATA/FACTORS FOR SO2 AND NOx EMISSIONS FROM HOSPITAL WASTE INCINERATORS Cedar Sinaia St. Agnesb Medical Center Medical Center Emissions Los Anoeles. CA Fresno. CA Factor Pollutant (lb/ton (lb/ton (lb/ton (ppmv) feed) (ppmv) feed) feed) Sulfur Dioxide High 50 3.01 20 1.54 3.01 Low 25 1.51 19 1.47 1.47 Average 37 2.22 19 1.47 1.85 Nitrogen Oxides High 270 7.82 155 5.75 7.82 Low 160 4.64 155 5.75 4.64 Average 217 6.29 155 5.75 6.02 aReference 26. bReference 27. • • 890958 CML.026 3-20 TABLE 3-5. DATA/FACTORS FOR PARTICULATE EMISSIONS FROM HOSPITAL WASTE INCINERATORSm Emissions Add-On Incinerator Particulate Factor Control Device/ Feed Rate Loading (lb/ton Hospital Heat Recovery (lb/hr) (gr/dscf) feed) Cedar Sinaia Fabric Filter/Yes 980 High 0.002 0.10 Low 0.001 0.05 Average 0.001 0.07 Swedish-Americana NR High 175 0.209g 2.39 Low 172 0.050g 0.57 Average 174 0.127g 1.45 Queen of the Valleyh NR High 412 0.105 1.4 Low 374 0.073 0.85 Average 396 0.084 1. 1 St. Agnesb None/Yes 783 High 0.090 5.45 Low 0.080 4.84 Average 0.080 . 5.15 Illinois Unitd None/No 500-800 High 0.170 3.20e Low 0.020 2.00 Average 0.040 2.60e . University of Michigani NR High 0.0468 3.42 Low 0.0382 2.77 Average 1493 0.0438 3.16 Royal Jubileec None/No 1930 High 0.028 1.82 Low 0.022 1.37 Average 0.025 1.60 Athabascaf None/No 85 0.050 26.92 Willingdon None/No 130 0.070 1.69 Bonnyville None/No 130 0.080 11.85 CML.026 3-21 890958 . . TABLE 3-5. DATA/FACTORS FOR PARTICULATE EMISSIONS FROM HOSPITAL WASTE INCINERATORS01 (CONTINUED) Emissions Add-On Incinerator Particulate Factor Control Device/ Feed Rate Loading (lb/ton Hospital Heat Recovery (lb/hr) (gr/dscf) feed) Lacombe None/No 150 0.070 5.87 Ft. McMurray None/No 265 0.050 13.28 W.C. McKen. None/No 275 0.020 3.20 Red Deer None/Yes 410 0.080 36.49 St. Michaels None/No 465 0.080 1 .70 Queen Elizabeth II None/No 575 0.030 6.12 Queen Elizabeth II None/No 700 0.030 . 2.70 E 740 0.060 2.97 Misericordia None/No I Misericordia None/No 740 0.100 4.76 Northwest None 1,015 0.22g 6.7 Medical Center Royal Alex None/Yes 1,160 0.030 3.41 Royal Alex None/Yes 1,200 0.070 3.30 Foothills None/No 2,500 0.060 1.76 Lethbridge Gen. Wet Scrubber/Yes 1,060 0.040 2.12 Univ. of Alberta Wet Scrubber/Yes 1,400 0.020 1.23 North Erlangerl NR 0.0752 High w 0.0434 ` Av 0.0565 Average South Erlanger1 NR 0.0913 L High 0.0536 Low 0.0743 Average CML.026 3-22 890958 TABLE 3-5. DATA/FACTORS FOR PARTICULATE EMISSIONS FROM HOSPITAL WASTE INCINERATOR? (CONTINUED) Emissions Add-On Incinerator Particulate Factor Control Device/ Feed Rate Loading (lb/ton Hospital Heat Recovery (lb/hr) (gr/dscf) feed) Mediwasten None 1,200 0.08 5.6 Shore Memorial° None 600 0.06 1.5 Nyack HospitalP None NR 0.16 1 .5 aReference 26. bReference 27. cReference 28. dReference 29. °Based on emissions factors presented in Reference 29. fAll of the information from Athabasca to Univ. of Alberta are from Reference 30. 9Corrected to 12 percent CO2 bReference 40. iReference 41. iReference 42. • kReference 44. 1Reference 45. mAll the incinerators identified in this table were two-stage controlled air units. The University of Alberta unit had a rotating hearth for a primary chamber; all other units had a fixed primary chamber. °Reference 46. °Reference 47. 'Reference 48. 890958 CML.026 3-23 S several states require hospital incineration units to meet PM emission limits. Therefore, testing is carried out on a routine basis. In addition, as previously stated, vendors frequently offer guarantees regarding PM emissions. The PM emission results in Table 3-5 include the results of the comprehensive emissions tests (the first four hospitals) and test results obtained from the survey article.31 These units are the same units for which HC1 data were presented. The data shown from the survey article are arranged in order of ascending feed rate to show any effect of unit size on PM emissions. The emission factors in Table 3-5 show no clear trend between specific PM emission rates and unit size. It is interesting to note that the highest emission factors (above 10 lb/ton feed) are associated with the smaller units (below 400 lb/hr) . Based on the information in Section 2. 1, these units may well be retort-type incinerators. Unfortunately, no design information is available to confirm this hypothesis. Emissions results for units operating with PM control equipment are also shown. in Table 3-5. The Cedar Sinai unit, which was installed with• a fabric filter for PM control , had the lowest PM emissions factor of those presented. _ The control efficiency for the filter was 98 percent. The other two units which had PM control equipment are the Lethbridge General and University of Alberta units. The emissions factors for these two units are considerably higher and are not markedly different from incinerators operated without PM control equipment. Both wet scrubber systems for Lethbridge General and the University of Alberta are designed and operated for acid gas control and not for PM removal . In general , wet scrubbers designed for acid gas removal operate at low gas-side pressure drops for purposes of low energy consumption. High energy and high gas-side pressure drops are required to obtain high efficiencies for PM control . Unfortunately, no inlet data were given for these units, so the control efficiencies could not be determined. 3.2.3 Trace Metals Table 3-6 contains a summary of the available trace metal emission data for hospital waste incinerators. An emissions factor based on the waste feed rate to the unit is also given for each of the emissions rates 890958 CML.026 3-24 I S :a O 0 P . 1 �- O1 w 0 0 eO . . 0 0 n . 0 w �i 11 111 wr n /wl a COw . Pi . n n 4 n 0 O e w St 0 • 1 pp Y M N w1 !� M •r •0 we e w e n N i i i ee w e 6 .7- . . n al0 2 « 2 A 3 10.1 Y 2 n O 1. WI 0 E h ▪ N .... O o e .4 ..4 a w a Si .- . n w N ✓ a •• r i . g . N 0 9 O 0 n e n N N O e e ✓ N 0 0 0 N N N O n e i I1 i 1 1 1 iIa g ' 000 nn0 w2 $ en . .Iii a M e 0 0 . n w n w N w n .� N w n w M N f v 114 aN 0 0 • w w w N N WI M VI N N I O 0 e o a 1. n n n n i N n 1 1 1 w w w 1 1 1 u. i I .• N n y i N N n e Non . e e w ry e ▪ w O O O ^ . V) 0 n w 0 0 e 0 n 0 1 v w M M w e a N 4 10 IN pI iii Al9: s3A V 3 4 111 N N N g . • S I is N 0• 0 0 •: O•P O S V • n N.� n O N _ 0 0 0 n w w e el a 0 0 e all w 1. N n w 0 I M atSee • O O 00 : .n. e env . al 0 0 0 P N . ..1 n e O e n 1 1 1 IIte • M n N N 1 1 I e 8 0 0 0 0 0 0 r e e 0 N n . 0 n N yy • Z N . . N n n w N = .. n • M V O e O w21 0 . • 1 w a w . 1, e • _ O Y y .. 0 0 0 00 N H e n N . O 1 1 1 Si e v M n 0 e . n n N n I w we .. pi 8n Sin . O O s V IA a . M e N .. - 9 e . N w n n e C N 0 0 O 0 N w Na. N o w e e 4 N O w au a 0 le 0 M a 0 00 . .0 • 9 0 O I� n w 14 V •i • O O O n n. . w N 4 e e 1I 1I 1 Y a 9 IN . Y ' 1 • a 1 • El .. rM a a a to n lean w Ii 11 ■ O 9 e • i a I o 17 Yl i N n • a a r tt w s� [r[ : t r 6 a tt e . . . i1i i3i i � i iii • C zzI * M N W CML.026 3-25 Ei f`�a 890955 • presented. In addition, for the Cedar Sinai unit, results for upstream and downstream of the fabric filter are presented. No additional trace metals data were identified by the study. Because two of the reports are from California, a state recently beginning to require testing, it can be assumed that future tests will be a source for additional data. Analysis of the Cedar Sinai data indicate that there is a substantial reduction in trace element emissions across the fabric filter. No apparent trends in the data were observed relating trace metal concentration to incinerator size. 3.2.4 Organic Emissions Tables 3-7 and 3-8 contain summaries of the available emissions data for CDD and CDF compounds from hospital incinerators. An emissions factor based on waste feed rate to the unit is also given for each of the concentration value presented. The homolog emission data from three emissions tests are shown. Limited isomer emission data were available for the Cedar Sinai and St. Agnes tests. For the Cedar Sinai unit results from • both upstream and downstream.of the fabric filter are presented. At this time, these are the only finalized COO and CDF emissions test results for hospital incinerator units which have been reported. An addi- tional unit located at Stanford University Medical Center in California was also recently tested for CDDs and CDFs.32 The results of this test were not available as of the writing of this report. The. California Air Resource Board (GARB) has recently begun to require testing for CDDs and CDFs at newly installed hospital incinerators, so additional data will be available through CARS in the future. Analysis of the emissions data presented for the unit at Cedar Sinai indicates that for most of the dioxin and furan homologs, a slight reduction occurs across the fabric filter. The subgroups for which this reduction was not seen are the TCDD and TCDF homologs. Ash analyses for the Cedar Sinai incinerator are presented in Table 3-9. No statements can be made relative to trends in the data related to unit size or operating characteristics because too little is known about the operation of each of the facilities during testing. tML.026 3-26 890958 ' • 1 8 C O to- P. II w N N R+ w w a n n n 1 ■ 2 .a I O O n w n . P N w e n + 1 n N • C N .• n. r• � • a n O O 0 0 0 n 0 0 ., O M n O N n a WM .0 e • q + n N N n n O N n .• . .� n n n o • a as• O aag wn . ►1Nn •1n . w n + N . e ■ •1 • 0 0 0 O O O 0 0 0 0 0 0 N n n M r ♦ • A a • C .4 N N II a A N • O O 1/2 IN a + .w • N w N N . n n 1 n e w 4 i > ■ Ii a . w •P a .n. .P i .4 w CI el n !NI n3 1 p'y ES w P e + e w N N n n n . w N . e ■ u m e o n + . n n o N e N o 1 e M n + O ■ i• 21 2 W w n O 0 O O O n n w n N n a n . w a w 0 II r q a w w e N P 1 n + e a a e e .B e e e • II ₹ O` _ I I o n e e t-2 + w n a Y 1 a R g e GM Ce N N w N •� . .nl e w a w w . N a O . 8. 0 . 1 a Na . n a e 0 1 n N n 0 Na : tt • • i J S M O O II N N w . + n n 1 a n •1 e P O a .4 000 000 000 44a a N n .. . N n • - • • • s■ e + M •• i • i i 4 S n n n N O a n w P • . . O .1 a 0 0 n u a + N . .+i .ni w � NII � 0 ti r VI ✓1 � .e.1 a r w N N C` ► y 3 y. S •�O MM .. 2V' S .111 . I 000 • m . • + � r 0 • � •.+O M N O e O 0 0 0 0 0 0 n n M 0 0 0 N N N F A • C I N v v • u a : a s : to a.• • Y 38IiY • A d ' . : SR : 223 • 3 3 R .e.•3 « Pi RS 332 • I sC .iwe �.. .+. « � « me ne+i .NI R « « . i� n n n • N N N S QtlSp • y Q C C C$ ! 33 7 ^9t 7 �3 7 :1t e7 Yat " !! '4" Fail • Ma .ls jm ] i gg l 8 • - ali •. MAge.," CML.026 3-27 • 890958 I i 1 QS� w^ o +ein n8 « VI are raa OD••• A vi • "g 8 : :: r c O N n: : • o n e e N a n r C Y O ^ e ^ ^ p • r el n2 o . . n e n P • O P ^ w • VI N n • r P a w w e4 n n N " r a r r v 0 0 0 r O r r O r 0 0 0 0 0 0 n n a S : s : " Leo 5 : S < y i ► I P• O rw f4. n ill P 1ew nw �w• n e a ... N vl VI • i 1m a w i N n 0 p .ny r p r r 1 O n ' a • N w n V • t L •'a O • P n a e • • O • r n n r N • a .. 0• ,. (.1 y a v N a a n n n n • n p • n a • a el w N a Crwi • r I s ; l P. . . O 0 • • 0 0 O • • . O O .O O a a : � eVaa 222 � sx ii i : a . r r r n n w Q S -.`` IS O1p r r w • r • n N N P N P n • w a tY a S r O P P. O If w w • r O N P n e w rii aIN • MO r N wM VI 4.4N - NNn nwfM I Ili. w • w a • • i If Y • • I • n N 10• P• . O• e e O p n e• • w• r• O• e• n •r 10 141 0 P.01 Ifl r • n 4.1 5 .: 3 « • re R .n. « n : : S .". • w 'a « ea9 in M 3 a : J 2w � .: : .i : r .; :w : « «« r: : : : : • r • 44 • oaf di YAI • • 3^ r .•.w e E iw E S i Se .'� S r S ee w Z IS a "+ x • � S : � S : SSS SS : rxs • ^ ^^ a w N • 3 c I 1 «• � � -• • t g 3 I I 0 3 i jamsA Em3E a .- Ii 1m .ii Aji.- y4 yr CM—026 026 3-28 890958 TABLE 3-9. FABRIC FILTER DIOXIN/FURAN ASH ANALYSIS FOR CEDAR SINAI INCINERATORa Loadings (n8/9) • Dioxins Tetra 1.6 Penta 3.7 Hexa 8.9 Hepta 33.6 Octa 65.7 Total PCDD 114.0 Furans Tetra 13.6 Penta 19.0 Hexa 22.6 Hepta 42.2 Octa 43.5 • Total PCDF 141.0 aReference 26. CML.026 3-29 • 890958 Table 3-10 contains emissions factors for the low molecular weight organics for which emissions results were identified. These factors were determined from information collected at three of the comprehensive test sites. 3.2.5 Carbon Monoxide The CO emissions data which were identified during this study are presented in Table 3-11. Also presented are the hydrocarbon (HC) data which were found. It should be noted that the HC data are reported as propane. The CO concentrations measured were below the detection limit of 50 ppmv and are, therefore, reported as less than 50 ppmv for two of the three inciner- ators tested. The concentration of CO from the Swedish-American incinerator was reported at 9.5 ppmv. A comparison of the HC emissions factors of Table 3-11 to the LC factors of Table 3-10 suggests that only a small portion of the total HC reported in Table 3-11 is comprised of the compounds listed in Table 3-10. A definitive conclusion can not be reached, however, because the results presented are from different tests. 3.2.6 pathogens Bacteria There are primarily two routes by which pathogens may be released into the environment from incineration of infectious materials. These are: 1) discharge air streams; and 2) post-incineration residue. As part of a recent test, 15 samples were taken from the stack of a hospital waste incinerator which had been charged with hospital waste containing pathogenic materia133. Bacteria with a mean concentration of 231 colonies/m3 of gas sampled were found in the stack as opposed to an ambient mean level of 148 colonies/m3. However, due to experimental uncertainty, no statistically significant difference could be found between the two measurements. Tables 3-12 and 3-13 show the results of a U. S. Department of Health Study which measured the bacterial population of residues from various types of municipal solid waste incinerators.34 No data were located regarding bacterial populations in residue from hospital waste incinerators. Evaluations of atmospheric release of pathogens in incinerator discharge air streams have primarily focused on the minimum operating temperature required to prevent this release. Laboratory studies report CML.026 3-30 890958 TABLE 3-10. EMISSION FACTORS FOR SELECTED ORGANIC LOW MOLECULAR WEIGHT ORGANICS FROM HOSPITAL WASTE INCINERATORS Emissions Factor Reference (lb/ton feed) Source Ethane • E <0.003 24 Ethylene <0.02 24 Propane <0.024 24 Propylene <0.022 24 Trichlorotrifluoroethane 8.25 x 10-5 21, 22 Tetrachloromethane 9.91 x 10-5 21, 22 Trichloroethylene 2.39 x 10-5 21, 22 Tetrachloroethylene 2.49 x 10-4 21, 22 • CML.026 3-31 890958 N C C O ma.+- O N -0 0 Col N O1 N t N is \ W • N 0 ,.y N V .0 41 01 r1 - •r A r Y- V V V 0 0 0 E W W C .•. "CIW ma d m. ICI 01 C W O N d 1s- •-• 0 0 7I C.) J T r V S. A 6 el n •1cg .O N O in = O O WI T 2 01...W O. pO O1 20 2 .. C I— W C O W F.. 2 x.. C .••. =2 O 1 Os 01 01 -. N .•. 1••' L 10 IO IC CM O. .-1 H 0 .0 I _ -w .•a -.1 0 0 0 N N C v V V V CC 31 C 6 01.1 1 G H . V a. O r W d N "Cl 0 0 0 .Ir w.1 in Col CU 1. in in ICI C 2 = a V V V O r E c z N N O — in N N co) C — N N CM 01 N A = A W a0+ 0 N1 PI en N ... .-1 L W 0 0 0 am CC C .CI .0 W V. - V V • _ in 41•;.i ..+ in •me N W ..•1 r Y X Iml 411 J 1.1 41 p N in in ^ ~I ~ co i V V V V y JI f' L E W — • Cl.r CO C CD W _ � -•C O G N N W N (J CD C O W W WIZ . C = w 0. 0 C C 4.1 .°1.1 '0 + C t L N L L i i i u C .. CD 3 0 01 = W A as ar 0 W W W C/ S.r r O > v T > W W W S. r r i = J < = J < W. W W O W d u = w.0 uv CCO LI CML.026 3-32 890958 L C N. --. CU C O CJ ♦N a ila C `QQ 0 = 0 LI �0 c 17 Da O N it .7 0 Cd O . in• U CO a N N fa 1 r r 10 C 1 ll 00 ..- C 0 7 CO N CO 00i CC r v 0 _ D1 L L N i C O C i- F. V CJ W N .— a.(J IV F- 7 T v0 N in 17 C 0 0 .7 LC) ..*O = r O 7 1 W N N r N LC) JC ...r aua f c an— L 00 01 O .•a 17 17 > DI > -.1 Y N 0 0 0 1 • 0 W ^10 N N 0 CO O 0 0 m0 V I vN v G O O N O CC J A W Li. U a =O a ✓C r • U _ L 1•+-S 0 ti N 00 q in r - O f as =�I N a •.n a V CO . r r ral N CO L 1 '. - in N C CI 0 CO W2= Cd CDCOC •F CF. CC C .a v = F-N {.I W U. —. C Ci C VI ClP. 000 0 Col Lm 0 3 - -0 N 1. • 1.a 10n C CI> 1 ra I HY N 0 CO O t Pa C• C L 0 0 • C L .. 0 I- CO CO r Si 1 Ri a 01 O. in r ..... L W = J .-. O CO L .0 C a C F. N N > et .-. N C 0 N U f L O v .7 — 7 P9 CI I.7 C v0 C O. CI M C C L L V N Al I- alN >1 N 0 L U U �1 CI O I L m ■ L y s r UUC 41 a ■ C O1 L I. 1f N T C1. L.3 N « 0 T « > CL V W C-.i W a C C 7 a la •• N « N T O XI a d 1n N Cl O i 0 N N r- U E L L L T C C Si L N CCt « O x s. yN CI y a a 0= W CD O O I- C W m CML.026 3-33 890958 O c o o 0 O r .. r .. r .-e x x x x x x co A N In r f r 0% it r N A f on V A f Lel 01 I0 in r W O O .. .O. .O. .O. .O. .0.. .O. et X XXX XXX H N V 1O P.. f N N 01 .. O_= O N in ..4 r en f in se S' N 1.O L VI r eV W J C Co VI Y W C ZJ r I- C O O O O O O O O.= r r r r r •••Ir r P .U X XXX XXX r VI E ... 00 OD O ••••• O• en • f • ID f f r N N 01 I •2 W= O 0 O W n f in V. P� to f Nf O O O O H..a .. .. ... .. - O .. . ..O O . . • derc8 x x x x x x x x N LW CAZ y e0 N N •••• f O 10 f r le •CP. W IO 0% f r r .eV N ••C L r O O1 M IL u L O va LI <•-• u VIE VI .O N Si (L.1 Ina E E jr C L L C L G L WW 5IY W 2 .O VI - M W W N ♦. 44.• of W F- a — in — — — Si r r gi O mi. •.• r— r— r� S. L. L- es-• C Si O O 01 N O O O1 O1 0 01 LC V 01 Y V Y L vu L L 1 L C01 en M= a +' Pao A a 41 a A of O. G C u O. *. sea u M a ♦. Y en — W 00 O WOW OWOW N N J m I- x W I- s I- IL o .+ W L u C s o IC 0 O " . W N eV CI r eF N N • C w a en m -- I W0 N a = S 49 {e,111 N N A L V V L L ID 0 ~ L d T t 9 O. O. 0 •' •.- ill Si O x x N a N C VI V V • CML.026 3-34 890958 - a chamber temperature requirements of 575°F (302°C) for destruction of vegetative cells and 1,600°F (871°C) for spores.35'36 The minimum operating temperature is an incinerator-specific phenomenon which can be determined only by challenging the unit with highly resistant organisms and measuring bacterial content of stack emissions to determine the temperature required for sterilization.37 3.2.7 Preliminary Emission Test Data Presented in this section are preliminary emissions data for six hospital incinerators. Tables 3-14 through 3-16 present preliminary emissions data for three hospital incinerators located in California; these data, presented at the Hospital Waste Combustion Workshop in Baltimore, Maryland in May 1988, represent the high emission values obtained during stack tests.38 Table 3-17 presents preliminary results of emissions tests performed at three biomedical waste incinerators (BWI) located in Canada.39 All these emissions test data are preliminary; the accuracy of the data has not been assessed. For the sake of completeness and for future reference, these data are presented separately from the previous emissions data. Furthermore, due to the preliminary nature-of the data, these data have not been included in the estimates of the emission factors. In reference to Table 3-17, it should be noted that the concentrations of HC1 reported for incinerators 81 and B2 are arithmetic averages and do not account for the variable flow rates as a result of batch testing. No microorganisms were detected in the air emissions or ash deposits of the three Canadian biomedical waste incinerators. Continuous monitors were used to measure opacity, THC, and CO emissions at two of the Canadian biomedical waste incinerators. Measurements were taken over 24-hour periods when the incinerators were operating as well as when they were not operating (i.e. , during 'dormant" periods) . The preliminary results showed that opacity levels were significant even during dormant periods and peaked during the ash clean-out period prior to incinerator startup. In addition, THC and CO emissions were also significant during dormant periods. These emissions are ascribed to the continued pyrolysis of unburned waste present in the ash and left in the furnace overnight, sustained by air entering through open doors or leaks.50 CML.026 3-35 890958 TABLE 3-14. PRELIMINARY HC1 AND PM EMISSIONS TEST DATA Incinerator Emissions Feed Rate HCl PM Hospitals Controls (lb/hr) (ppm) (gr/dscf) . Aa Met Scrubber 550-805 1.86 0.003 Bb None 369-593 315 0.057 Cc None • 70-100 770 0.04 aTwo-chamber controlled air incinerator.. bTwo-chamber controlled air incinerator. cSingle chamber incinerator with afterburner. ND - Not Detected • • • 890958 CML.027 3-36 TABLE 3-15. PRELIMINARY METALS EMISSIONS TEST DATAt Hospital Arsenic Cadmium Chromium Iron Manganese Nickel Lead Aa 0.01 0.50 0.07 5.90 0.06 ND 11.58 6 0.01 1.55 0.25 24.0 0.60 ND 27.9 C 0.29 7.43 ND 16.86 0.86 ND 102.57 aUnits for all data are gm/ton. ND- Not Detected • CML.027 3-37 890958 TABLE 3-16. PRELIMINARY DIOXIN AND FURAN EMISSIONS TEST DATAa Dioxin Furan Hospital TCDO PeCDD HxCDD HpCDD TCDF PeCDF HxCDF HpCDF Aa 0.02 0.10 0.49 1.72 0.21 1.37 3.86 5. 11 B 0.14 14.60 44.10 169.00 6.05 67.6 213.9 292.4 C 0.004 0.038 0.196 1.575 0.038 1.492 1.829 5.242 aUnits for all data are ng/sec. CML.027 3-38 590958 .. Q R - C o - In S W N Nro n I n. M .+ • • li v. • e 8 . F a g g C a N a - N .. • - iI e e i 2 II . 9 • . - I6• ID a I I .... 1. • s ! D If ® • w a� � � r gg ., .. • g• S - 3 i i .. 2 ! 0 P.: 44 • M 2i ael + • 2 • N s • .. ., S G • . a • a. ... a 3 ° g '" a If •F- _ .. a t v 1 y • w U w .. • II Y 3� • E •S . 4p Ypp • 3 sea N .2• i i i � a a. a CML.026 3-39 890958 • 3.3 REFERENCES 1. Doyle, B.W., D. A. Drum, and J. D. Lauber. "The Smoldering Question of Hospital Waste.' Pollution Engineering, 17:7, July 1985. p. 35. 2. Kaiser, E. R. and Carotti, A. "Municipal Incineration of Refuse with Two Percent and Four Percent Additions of Four Plastics: Polyethylene, Polyurethane, Polystyrene, and Polyvinyl Chloride, "Proceedings of the 1972 National . Incinerator Conference", June 1972. pp. 230-245. California Air Resources Board. Air Pollution Control at Resource Recovery Facilities. May 24, 1984. 3. Reference 1. 4. Seeker, W. R., W. S. Lanier, and M. P. Heap. Municipal Waste Combustion Study: Combustion Control of MSW Combustors to Minimize Emission of Trace Organics, EPA 530-SW-87-021c. U. S. Environmental Protection Agency. Washington, D. C. , May 1987. p. 4-9. 5. Reference 4. p. 4-10. 6. Edwards, J. B. Combustion: Formation and Emission of Trace Soecies, Ann Arbor Science Publishers, Inc., Ann Arbor, Michigan, 1977. (Second Printing), p. 65-68. California Air Resources Board. Air Pollution Control at Resource Recovery Facilities. May 24, 1984. 7. Henry, W. M., R. L. Barbour, R. J. Jakobsen, and P. M. Schumacher. Inorganic Compound Identification of Fly Ash Emissions from Municipal Incinerators. PB 83-146175. U. S. Environmental Protection Agency, Research Triangle Park, North Carolina. October 1982. 8. California Air Resources Board. Air Pollution Control at Resource Recovery Facilities. May 24, 1984. 9. Reference 6. 10. Jacko, R. B. and D. W. Neuendorf. "Trace Metal Particulate Emission Test Results from a Number of Industrial and Municipal Point Sources." APCA Journal Volume 27, No'. 10, October 1977. p. 989. 11. Trichon, M. and J. Feldman. "The Formation of Trace Toxic Metal Emissions Resulting from Incineration,' Roy F. Weston Company, NJ. Presented at Air Pollution control Association National meeting, Poster Session. June 24, 1987, New York, NY. p. 10. 12. Reference 6. 13. Block, C. and R. Dams. 'Inorganic Composition of Belgian Coals and Coal Ashes," Environmental Science and Technology, Vol . 9, No. 2, February 1975. pp. 146-150 as cited in reference 23. CML.026 • C3-40 890958 14. 6allorini , M. , et al . CEP Consultants Ltd. Heavy Metal Contents 1n the Emission of Solid Waste Refuse Incineration. 1981. p. 56. dering j15. Linak, W. P., et al . 'On the Occurrence of Transient Puffs in a Rotary 985. p�u35t�? Kiln Incinerators Simulators.' Journal of Air Pollution Control Association,. January 1987, Volume 31, No. 1. n of Refuse wi16. Reference 5. p. 4-3. Polyethylene, roceedinas of 17. Germanus, D. 'Hypothesis Explaining the Origin of Chlorinated Dioxins p. 230-245. r and Furans in Combustion Effluents.' Presented at the Symposium on 1 at Resource Resource Recovery, Hofstra University, Long Island, New York, 1985. ! 18. Axelrod, D. , MD. 'Lessons Learned from the Transformer Fire at the Binghampton (NY) State Office 3uilding.' Chemosphere 14 (6/7), 0Waste Comb' P 775-778. ze Emission 1 19. Olie, K. , M. V. D. Berg, and 0. Hutzinger. 'Formation and Fate of PCDD :al Protectior and PCDF Combustion Processes.' Chemosphere 12 (4/5), p. 627, 1983. 20. Hutzinger, 0. , M. J. Blumich, M. V. D. Berg, and K. Olie. 'Sources and Fate of PCDD and PCDFs: An Overview.' Chemosphere 14 (6/7), p. 581, Trace Soecii 1985. 977. (Second 21. Reference 3. Air Polluti( 122. Technical Report, 'Municipal Waste Combustion Study;. Recycling of Solid Schumacher.. Waste,' Prepared by Radian Corporation for U.S. Environmental Protection Agency. EPA Contract 68-02-4330, p. 5-6. from Munioche r action Agency 23. Remarks of Dr. T. Galdfarb at the Conference 'Health, Environmental and Financial Impacts of Trash Incineration" George Mason University at Resource November 15, 1986, Fairfax, Virginia. ! 24. Doyle, B. W. DrUm, D. A., and Lauber, J. D., 'The Smoldering Question of Hospital Waste," Pollution Engineering Magazine, July 1985. late Emissi 25. Radian Corporation. National Dioxin Study Tier 4 - Combustion Sources, Sources." EPA-450/4-84-014h. U. S. Environmental Protection Agency, Research Triangle Park, North Carolina, September 1987. 26. Jenkins, A., 'Evaluation Test on a Hospital Refuse Incinerator at Cedar xic Metal Sinai Medical Center. Los Angeles, CA,' California Air Resources Board, ompany, NJ. ! April 1987. meeting, Pc 27. Jenkins, A. , 'Evaluation Test on a Hospital Refuse Incinerator at Saint Agnes Medical Center, Fresno, CA,' California Air Resources Board, January 1987. an Coals and ). 2, Februi CML.026 3-41 890958 28. Bumbaco, M. J., 'Report on a Stack Sampling Program to Measure the Emissions of Selected Trace Organic Compounds, Particulates, Heavy Metals, and HC1 from the Royal Jubilee Hospital Incinerator. Victoria, B.C." Environmental Protection Programs Directorate. April 1983. 29. Allen, R. J., G. R. Brenniman, C. Darling. Air Pollution Emissions from the Incineration of Hospital Waste, Journal of the Air Pollution Control Association 36:7 1986. pgs. 829-831. 30. Powell , F. C. , 'Incineration of Hospital Wastes the Alberta Experience," Journal of the Air Pollution Control Association, 37:7, July 1987, p. 836. 31. Reference 25. 32. Meeting Notes from Ecolaire Presentation, August 4, 1987, at Radian Corporation. 33. Kelly, N. , G. Brenniman, and J. Kusek, . 'An Evaluation of Bacterial Emissions from a Hospital Incinerator,' Proceedings from VIth World Conference on Air Quality, Vol . 2, May 1983, pp. 227-234. 34. Peterson, M. L. , and F. J. Stutzenberger. 'Microbiological Evaluation of Incinerator Operations.' Applied Microbiology, 18:1, July 1969. p. 8-13. 35. Barbeito, M. S. , G. G. Gremillion. Microbiological Safety Evaluation of an Industrial Refuse Incinerator,' Applied Microbiology, February 1968. p 291-295. 36. Barbeito, M. S., M. Shapiro. 'Microbiological Safety Evaluation of a Solid and Liquid Pathological Incinerator,' Journal of Medical Primatology. July 1977, pp. 264-273. 37. Reference 32. 38. Private communication between G. Yee, California Air Resource Board and R. Morrison, U. S. Environmental Protection Agency, June 22, 1988. 39. Ozvacic, V. 'Biomedical Waste Incinerator Testing Programs in Ontario," Biomedical Waste Workshop, San Francisco, May 10-12, 1988. 40. 0ueen of the Valley Hospital Test Report, Chemecology Corporation, Emissions 'Test Results of Incinerator at Queen Of the Valley Hospital , Napa, California, July 1985. 41. Swedish-American Hospital Consumat Incinerator, Beling Consultants, Test Report for Swedish American Hospital Consumat Incinerator, Rockford, Illinois, December 1986. 42. University of Michiaan Medical Center Test Report, Almega Corporation, . Emission Test Results of Incinerator at University of Michigan Hospital , Ann Arbor, Michigan, May 1987. CML.026 3-42 890958 43. $Cl Emissions from Hospital Waste Incinerators, Ian C. McCly.ont Proctor and Redfern Group Richard J. Urbanski Independent Measurement and Technology Emission Test Results of 10 hospitals in Ontario, Canada. 44. Summary of Results of Particulate Emission Determinations_ on No, 4 Boiler at Northwest Medical Center - Thief River Falls. Minnesota, Emission Test Results of No. 4 Boiler at Northwest Medical Center, Thief River Falls, Minnesota, June 1987. 45. Erlanger Medical Center - Chattanooga. Tennessee, Almega Corporation, Emission Test Results of Incinerator at Erlanger Medical Center, Chattanooga, Tennessee, February 1984. 46. Galson, Source Test Report, Particulate Emissions, Visible Emissions, and Combustion Index Testing of Incinerator A and B at Mediwaste, Inc., West Babylon, New York, September and October 1986. 47 York, Final Test Reported for an Emission compliance Test Program on a Pyrolytic Incinerator System at Nyack Hospital , Nyack, NY, Report No. 01-4550-00, November 17, 1986. 48. Environmental Laboratories, Inc. Test of Shore Memorial Hospital , Somers Point, NJ, September 1985. 49. Reference 39. 50. Reference 39, p. 4. CML.026 3-43 890958 4.0 CONTROL TECHNOLOGIES AND EFFICIENCIES To date, hospital waste incinerators have operated largely without requirements for add-on pollution control equipment or special combustion modification techniques. Municipal waste incinerators, on the other hand, have received closer scrutiny in recent years and considerable attention has been given to potential emission control techniques. The process equipment and systems used to incinerate these two types of wastes are similar in design and operation, at least for the larger, controlled air incinerators. This section extrapolates knowledge which has been gained from municipal waste incinerators to hospital waste incinerators and considers the applicability of various emission control techniques. There are three broad categories of methods which can be applied to the control of emissions from waste incinerators: (1) Source Separation, (2) Combustion Control , and (3) Flue Gas Controls (add-on control devices). The application of each of these categories of emission control to hospital waste incinerators is addressed in this section. 4.1 SOURCE SEPARATION Source separation refers to both the segregation of infectious and non-infectious wastes and the removal of specific compounds from the waste stream prior to incineration. As discussed in Section 1.2, from the experience of hospitals in Illinois, it may be estimated that about 85 percent of a hospital 's waste stream can be categorized as general refuse, while the remaining 15 percent is contaminated with infectious agents. Thus, segregation of wastes at the point of generation can reduce the volume of infectious waste significantly. During a visit of project personnel to the Iredale Hospital in Statesville, North Carolina, such waste segregation practice was observed through the use of colored trash bags. The extent to which this practice reduced infectious waste volume was not known, however. 890958 CML.027 4-1 After segregation of infectious and non-infectious wastes, further segregation of the non-infectious portion could be possible. Plastics and metal-containing components of the waste, such as sharps, could be segregated; this could result in lower HC1 , polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzo-p-furans (PCDFs), and trace metal emission rates. However, no data are available on the effectiveness of such practices at hospital waste incinerators in lowering these emissions. Another approach to possibly lowering HC1 and PCDD/PCDF emission rates would be to have hospitals use low chlorine content plastics. This could be accomplished if the health care industry were to use plastics such as polyethylene and polystyrene in place of polyvinyl chloride, which contains over 45 weight percent chlorine. Again, no data are available to 4 indicate the effectiveness of such practices on emissions from hospital waste incinerators. 4.2 COMBUSTION CONTROL Data presented in Section 3 illustrate that there is significant variation in the uncontrolled emission rates from hospital incinerators. These variations are partially due to variability in chemical and physical properties of hospital wastes, partially due to variations in incinerator design, and partially due to variation in operating practices. This section addresses how waste combustion processes influence emission rates for the pollutants of interest and how combustion process control may be used as an emission control strategy. The general format is to address each pollutant .group separately, discussing how combustion processes influence the emission rate and how the adjustable process parameters may be used to reduce emissions and achieve emission control . The following sections provide discussions of the relationships between combustion processes and emissions of major pollutants of concern, namely: o acid gases, o particulate matter, o trace metals, and o polycyclic organic matter (including dioxin and furans) . CML.027 4-2 890958 i 4.2.1 Acid Gas Control The primary acid gas that will be emitted from a hospital waste incinerator is hydrochloric acid. As stated in Section 3.1, based on thermodynamic equilibrium considerations, any chlorine content in the waste will be effectively converted to HCl , assuming that there is sufficient hydrogen available. Therefore, based on the thermodynamic and kinetic consideration presented in Section 3.1, combustion modification does not appear to be a viable control approach for hydrochloric emissions from hospital incineration units. From a combustion control standpoint, emissions of SO2 are similar to HC1 . Thus, combustion modification is not a viable approach for SO2 emissions either. Based on NOX reduction techniques applied to other combustion processes, at least three control options may be applicable to reduce NOX emissions from incinerator processes: flue gas recirculation (FRG) , reburning, and ammonia (NH3). injection. However, none of these techniques are currently being applied to hospital incinerators even though they are being used on MSW incinerators. Flue gas recirculation is a technology which has been used for the control of NOx in boilers. FGR introduces a thermal diluent and reduces combustion temperatures. However, lowering of flame and furnace temperatures could be counter to the control of PCDD/PCDF. The significance of the detrimental impact of reduced bulk temperatures on PCDD/PCDF emissions has yet to be determined. Testing completed on the Pittsfield MSW incinerator by the State of New York could provide information addressing the impacts of FGR when they become available. Information gained from this test and other future tests could be used to further evaluate the potential application of FGR to hospital incinerator units. Reburning is used for a control technique which uses a hydrocarbon-type fuel such as natural gas or oil as a reducing agent. Hydrocarbon radicals produced by the reburning fuel react with NOx to form N2, H20, and CO2. This control technology is being developed for use in fossil fuel-fired - CML.027 4-3 690958 p boilers because only minor modifications are required to the main heat release zone. The effectiveness of reburning for NOx control in boilers has been shown to be a function of: - Initial NO level : the reduction decreases as the initial NOx level decreases. - Reburning fuel type: nitrogen-free reburning fuels are most effective, particularly at low initial NOx levels. - Temperature: reburning effectiveness increases as the temperature of the reburning zone increases. - Residence time: gas residence time in the reburning zone of at least 0.5 seconds is required to maximize the effectiveness of reburning. Two aspects of the reburning process make it attractive for hospital incinerators. First, it is a relatively effective control technique, potentially reducing NOx on the order of 50 percent. Second, the process of burning the secondary fuel increases both the flue gas temperature and the concentration of 0, H, and OH radicals. The high radical concentrations in the fuel-rich reburning zone drive the gas speciation towards the equilibrium state of complete combustion (i .e. , CO2 and H2O as products) . Thus, reburning not only provides an approach for destroying NOx, it also creates an environment which favors the destruction of any dioxins or furans created in the primary flame zone. Extensive research and development efforts would be required to develop reburning for hospital incineration, but the potential exists for a multi-purpose combustion control technology. A third option available for NOx reduction on incinerators is NH3 injection. When injected into combustion gases, NH3 can react with NOx to form diatomic nitrogen (N2) and water. The optimum temperature range for promotion of this NOx reduction reaction is near 870 to 1000°C. Thus, for application to a controlled-air hospital waste incinerators, NH3 would likely be injected either into the secondary chamber or into a seciton of the stack immediately following the secondary chamber. When this system (under the process name Thermal De-N0x) was applied to an MSW incinerator, with NH3 injectors located above the main combustion zone in the 870-930°C area, NOx emissions were reduced by over 40 percent.' To date, no known NH3 injection systems have been applied to hospital waste incinerators. CML.O27 4-4 830855 • 4.2.2 Particulate Matter Control As stated previously, particulate matter exiting the furnace consists of both inorganic material entrained into the combustion gases and organic materials which were not completely burned. In evaluating the influence of combustion control on PM emissions, it is necessary to separate the organic and inorganic fractions and to distinguish between the volatile and non-volatile inorganic contributions. When waste is fed into an incinerator, it is heated by radiant energy from the hot furnace walls and from burning combustion products above the bed. The waste is dried and, as the temperature increases, a devolatilization (pyrolysis) process begins. . The released volatile matter is entrained by the underfire air and begins to burn. Heat transfer from the burning volatiles to the bed material helps to ignite the waste in the bed and sustain the combustion process. The non-volatile, inorganic constituents of the waste generally remain in the ash pit. Non-volatile inorganics can contribute to the PM emission rate if an ash-containing particle is entrained by the underfire air and bea combustion products as they pass through the waste bed into the primary chamber. An ash-containing particle in the bed will be subjected to a series of forces including a drag force tending to accelerate the particle to the local air velocity and a gravity force tending to hold the particle in the bed. The drag force is proportional to the frontal area of the particle times the velocity differential squared. The opposing gravity force is simply gravitational acceleration times particle density times particle volume. Assuming a spherical particle, the gravity force varies with the diameter cubed. The ratio of drag force to gravity force will vary inversely with particle diameter. Thus, small particles are more likely to be entrained by the primary chamber combustion gases. If it is assumed that the ash content of hospital waste is approximately 25 percent and that emitted PM is totally inorganic, then the uncontrolled PM emission rate data presented earlier in Table 3-5 may be used to estimate the extent of entrainment. The PM emission rates were shown to vary from 36.5 to 1.37 lb/ton refuse. This estimate would indicate that between 92.7 and 99.7 percent of the ash remains in the ash pit. CML.027 4-5 89®959 I The volatile inorganic material in the feed will also contribute to the total PM emission rate. It is convenient to discuss combustion control of this PM fraction in the context of trace metal emission even though all of the trace metals emitted may not be associated with the particulate. A discussion of trace metal emissions is presented in Section 4.2.3. Finally, organic compounds are also associated with emitted PM. These organic components are generally heavy hydrocarbons, products of incomplete combustion (PICs), or polycyclic Organic matter (POM). An extensive discussion of these emissions and potential combustion control is presented in Section 4.2.4. 4.2.3 Trace Metals Control In Section 3.0, the available trace metal emissions data from hospital incinerators were discussed and it was pointed out that many of the volatile metals of concern tend to selectively deposit on the smaller particles. The physical processes responsible for these phenomena are complex, as is the potential influence of combustion processes on the associated phenomena. The following provides a brief review of key features which may be significant relative to hospital incineration combustion control . The majority of the available research concerning the process of fine particle metal enrichment has been performed on pulverized coal-fired utility boilers. Those conditions are somewhat different from the conditions found in hospital incinerators, but the basic processes should be similar in both systems. It has been found that the distribution of volatile metals among the different size fractions of ash is influenced by the quantity of ultra-fine particulate matter produced during combustion. Figure 4-1 illustrates this point in a plot of the fraction of arsenic and antimony collected with the ultra-fine particles (referred to as fume) versus the fraction of the total ash vaporized. A surface deposition model to interpret these data was developed. The model 's predictions for quantities of trace metal deposited on ultra-fine particles are presented as solid lines on Figure 4-1. The issue of how the metals are distributed throughout the total fly ash as a function of particle size has health effect implications as well as being an issue of engineering significance. Based on the probable CML.027 4-6 680958 .90 C=1.0 - m Surface Reaction Control E 80 Diffusion Control - IL ■ • «L+ .70 — o .80 C=0.1 - ■ A m O so U • 2 ■ C=0.08 ao E W Ts .30 c ■ As 20 A Sb t LL .10I l 1 I I 1 1 1 I I 1 .02 .08 .10 .14 .18 Fraction of Total Ash Vaporized Source: Reference 2 O Figure 4-1 . Fraction of As and Sb collected with Fume as a Function z of the Extent of Total Ash Vaporization (Data Points) S 4-7 898)858 mechanisms of fine particulate formation, it is suspected that the trace metals should tend to concentrate on the surface of fine particles rather than being uniformly distributed throughout the entire particle size range. The theory is that refractory oxides which are vaporized in the flame would be the first species to condense and would become the nuclei for the fine particulate matter. As the combustion gases cool , volatile salts of alkali metals and other volatile trace species would be expected to condense on the outer surface of these particles. A group at MIT, led by Professor Adel Sarofim, has confirmed this theory in several experimental studies.2 Figure 4-2 illustrates their findings in a plot of the concentration of selected species versus reciprocal particle diameter. The elements Fe and mg, which form the core of the particles, show no size dependence while those present as a surface coating show concentration variation proportional to lid. Note that the trace metals of concern for hospital incinerators were largely present as surface coatings. The key to the above observation is that the ultra-fine particles present a very high specific surface area and, thus, receive a disproportionate share of the condensing elements. Based on the findings of this research, any process that enhances refractory oxide vaporization would be expected to increase the number of sub-micron particles and to enhance the fine particle enrichment process. • The above information provides clues relative to the mechanisms responsible for trace metal enhancement on sub-micron particles. It does not, however, define a combustion control approach to minimize trace metal emissions. Incinerators operated with relatively higher temperatures in the fuel combustion zones should have higher concentrations of sub-micron particles which could potentially increase the trace metal enrichment process. Therefore, the use of controlled air, or two-stage, incineration with its lower primary combustion zone temperatures should reduce or minimize trace metal emissions. Unfortunately, data from retort-type incinerators are not available as yet to confirm this hypothesis. 4.2.4 folvcvclic Oroanic Matter (P0M1. PCDOs. and PCDFs Available data from MSW incinerators indicate that the PCDD and PCDF • emission rates are closely related to efficiency of the combustion process. CML.027 4-8 990955 Diameter mm 40 20 10 10' i i r O ii - O 3 5 m 10' - - _ V x - - O- Fe Q-G - V A- Na - A V-Znx102 - -Asx10° O-Sbx10' 10° I I 0.00 0.03 0.08 0.09 0.12 Inverse Diameter mm-' Source: Reference 2 Figure 4-2. Concentration of Selected Elements in Ultrafine 1 Particulates as a Function of Reciprocal Particle Diameter 1 4-9 ' 890958 I Generally speaking, when the flame temperature and combustion efficiency are increased, PCDD and PCDF emission rates decrease. Due to the overriding toxiological importance of these pollutant species, discussion will be presented on how poor combustion conditions can lead to POM, dioxin and furan emissions and how the combustion process may be controlled to minimize these emissions. Emissions and their control will be considered from the standpoint of the thermodynamic equilibrium and kinetics of combustion reactions. In addition, the formation of dioxins/furans subsequent to the combustion zone will be considered. The vast majority of the information on dioxin and furan emissions has been obtained only recently and primarily consists of stack emission rate measurements from municipal waste combustors. This information is taken primarily from testing results at large industrial and municipal incinerators; little work has been done on smaller hospital waste incinerators. There are also essentially no data from experimental programs specifically designed to identify the combustion processes responsible for PCDD/PCDF formation or to verify the effectiveness of proposed combustion control approaches on hospital waste incinerators. In the absence of direct data, discussion of how combustion modification might be used to control PCDD or PCDF emissions must be considered theoretical in nature. The PCDD and PCDF compounds are dicyclic, nearly planar, aromatic hydrocarbons within the broad category of POM. Polycyclic organic matter emissions have been the subject of intense investigation for many years with multi-ring compounds such as benzo(a)pyrene (BaP) being the primary species of interest. The following discussion is based on available information on how POM emissions are influenced by the combustion process. In basing the discussion on POM, the implicit assumption is made that variation in POM emissions corresponds to variation in dioxin and furan emissions. Fauilibrium Considerations. If waste material is mixed with air and allowed to react for sufficient time, the concentration of the resultant products is determined by the elemental composition of the mixture (moles of • CML.027 4-10 8009. 55 i• C, H, N, 0, Cl , etc.), the reaction temperature, and the thermodynamic properties of the species. Consider first the case of oxidizing conditions (excess air) in which the overall oxidation process is represented by: Waste + n102 —i• n2CO2 + n3H2O where n1, n2 and n3 are the stoichiometric coefficients required to balance the reaction and are dependent on the chemical structure of the waste. The equilibrium level of the unreacted waste in the combustion products is related to the concentrations of CO2' 02 and H20 by the equilibrium constant: n2 n3 PCO2 PH20 Kp - 1 Pwaste P02 • where P represents the partial pressure of a given constituent and Kp is the equilibrium constant. The equilibrium constant is related fundamentally to a measurable thermodynamic property called the Gibbs free energy (AG) by: Kp - EXP (-AG/RT) where T is temperature and R is the universal gas constant. Gibbs free . energy values are compiled in many sources. For typical stack gas CO2, H20 and 02 concentrations of 8 percent, the Gibbs free energy required for there to be 1 ppb equilibrium level of waste at 1,000K is roughly 40 Kcal/mole. The Gibbs free energy of furan at 800K is reported to be 492 Kcal/mole.3 Thus, Gibbs free energy considerations predict an equilibrium furan partial pressure of less than 10-100. The Gibbs free energy values for dioxins are even larger than those for furans; thus, the equilibrium concentration under oxidizing conditions would be expected to be even less. These considerations show that given sufficient reaction time and mixing, the • CML.027 4-11 890955 fundamental equilibrium limit for dioxins and furans may be considered zero for overall fuel-lean conditions, even at typical incineration operating temperatures. Since PCDFs and PCDFs can be formed in hospital incinerators, it is important to identify conditions where their presence is thermodynamically favored. An obvious area to examine is the high temperature, oxygen starved environment which is characteristic of isolated regions within poorly mixed combustion processes. An initial area to examine is high temperature pyrolysis without air which is the limiting case for poor mixing. TRW, Inc. performed an extensive series of equilibrium calculations for incineration of military pesticides.4 An initial set of calculations indicated that solid carbon (graphite) was a predominant species. Recognizing the kinetic limitations of graphite formation, a second set of calculations were performed eliminating graphite as a possible product species. Those results indicated greater than 1 ppm concentrations of a wide variety of POM species as well as chlorobenzenes and chlorophenols (potential precursors to dioxins and furans) . - The issue of poor mixing can also be addressed by examining the equilibrium product distributions for combustion of various chlorinated benzene/air mixtures.5 Sample results are shown in Figure 4-3 as concentration versus percent theoretical air assuming that the mixture is at the adiabatic flame temperature. With at least 45 percent theoretical air, formation of light hydrocarbon gases (e.g., CH4 and C2H2) is avoided. At 20 percent theoretical air, the formation of. benzene or toluene as equilibrium products is avoided. This leads to the postulation that POM, dioxins and furans are thermodynamically favored only if the incinerator creates very fuel-rich (and hence oxygen-poor) pockets of gas at low temperatures in the presence of chlorine. The above discussion illustrates two significant aspects of combustion control for POM. First, existence of these species (either in the flame or the exhaust) indicates a combustion process characterized by insufficient mixing and by local fuel-rich pockets of gas. These are the conditions which characterize the primary combustion chambers of controlled air incinerators. However, at temperature levels typically encountered in these • CML.027 4-12 890958 10° I 1 1 I I THC CO, Adiabatic CH. 10.2 — — C.H. C 10" — — O 10'° - CO, 750 K LL 2 10" — — CH,CI 10-1° _ - ]CCi.] <10-" Over Entire Range I 1 I I r 0 20 40 80 80 100 120 140 180 180 200 Percent Theoretical Air Source: Reference 5. • Figure 4-3. Adiabatic Equilibrium Species Distribution o 4-13 830855 units, there is no thermodynamic barrier to achieving essentially zero emission levels for these species and their precursors that are below the ppt levels. Kinetic Considerations. The preceding discussion addressed equilibrium formation of POM under excess air and starved air conditions. It is important to recognize that combustion of any fuel proceeds through a complex series of reaction steps leading toward (but not necessarily reaching) the product distribution predicted by equilibrium calculations. Some of these steps may be kinetically limited, however, causing certain reactions to be effectively terminated at an intermediate state. • Consideration of equilibrium conditions (see Figure 4-3) indicate that light hydrocarbon gases are thermodynamically not favored at mixture ratios above 45 percent theoretical air. Chemical kinetic limitations may, however, result in substantial concentrations of unburned hydrocarbon at stoichiometric ratios well above 45 percent. Experimental data obtained in the development of the EPA's low-NOx heavy oil burner may be used to illustrate this fact.6 Figure 4-4 indicates the measured total hydrocarbon (THC) concentration exiting the fuel-rich zone of a two-stage heavy oil flame. As shown, substantial THC was detected at first stage stoichiometric ratios below 80 percent theoretical air. The principal factor responsible for this hydrocarbon breakthrough was .depressed flame temperature due to heat loss through the furnace walls. The kinetic rates of chemical processes vary exponentially with local temperature. Similar experiments, • conducted in a higher temperature environment, showed negligible THC concentrations until the fuel-rich zone stoichiometry was less than about 60-65 percent theoretical air. In the above tests, the transition from fuel-rich to fuel-lean conditions was achieved through the use of multiple air jets designed to achieve thorough mixing of air with the effluent from the fuel-rich zone. By changing the split between primary and secondary air, it was possible to vary the fuel-rich zone stoichiometry while maintaining a constant overall excess air condition. In many respects, this is similar to the basic design in a controlled air incinerator. An important observation is that whenever the primary zone stoichiometry was sufficiently fuel-rich to cause CML.027 4-14 8. ©9. 55 I I 1 i 1 I 0 10.000 O A W A co - 0 H 3 1000 _ n 2 o d 100 _ . O - OQ . — G — 10 I I I a I I 0.8 0.8 0.7 0.8 0.9 1.0 1.1 SR, Source: Reference 8. 0 Figure 4-4. First Stage Hydrocarbon Production 4-15 hydrocarbon breakthrough in the primary zone exhaust, there was a precipitous increase in the boiler exhaust smoke level . The important point relative to hospital incineration is that the presence of substantial hydrocarbon concentrations in fuel-rich regions can easily result in the formation of soot and organic particulate matter. The secondary chamber must be designed to accommodate these materials to achieve complete burn-out. Equilibrium product distribution calculations for very fuel-rich conditions indicate ppm level concentrations of chlorobenzenes and chlorophenols. In one study, the likely chemical kinetic processes leading to formation of PCDOs were reviewed and it was concluded that the prime dioxin precursors are chlorinated phenols.7 Shaub and co-workers suggested a kinetic path for forming 2,4,7,8-TCDD, illustrated in Figure 4-5. The process proceeds by removal of hydrogen from the OH group, joining of two phenols to form a reactive 2-phenoxyphenol , and an elimination reaction to form dioxin. The above discussion provides several important insights into the combustion processes controlling the formation of POM, dioxins and furans. Those same insights indicate important incinerator design and operating parameters which might be used to minimize emissions of those species. Equilibrium and kinetic considerations both indicate that an essential feature required for the formation of POM, dioxin or furans is a fuel-rich pocket of gas. Defining how rich that pocket must be to form these species will depend on the local gas temperature. Increased temperature reduces the thermodynamic stability of the species (and their precursors) as well as accelerating the kinetic rate of destruction reactions. The discussion suggests that these POM compounds are, in all likelihood, formed in the primary chamber of controlled air hospital incinerators. However, these compounds must pass through the.oxidizing zones in the primary and secondary • chambers before being emitted to the atmosphere. The residence time and temperature characteristics of the overall combustion process will dictate, in large measure, the extent to which these materials are destroyed before flue gases are emitted. CML.027 4-16 890958 • A_ Mel) m • enj a u Y a O 0 OO O • i O • j coco 0 ,•• Ori N O w Y v v E Y tl7 C CO CDC p 2 _ o se `' t I ° O ta 3 O G u. Y y 1 14 C O uCiri y A co I O Y ti w i 4=17 830958 i• fuel Effects. A third issue to be examined is whether the chemical form of hospital waste has a significant impact on POM, dioxin or furan emissions. It is difficult (if not impossible) to accurately quantify the chemical form of waste being fed into an incinerator over the time period required to extract a sample for POM analysis. There are, however, data quantifying POM emissions from gas, oil , and coal-fired boilers. Figure 4-6 shows benzo(a)pyrene (BaP) emissions data from different size boilers firing coal , oil or natural gas. The shaded area in this figure represents coal-fired boiler results. Units with heat inputs greater than 1010 cal/hr were utility boilers while units in the 107 cal/hr range were small stoker-fired or hand-stoked coal furnaces. The measured BaP emissions from gas and oil-fired boilers were generally on the same order as those from coal-fired utility boilers. Utility boilers burn pulverized coal in large diffusion flames which are very similar to the flame types in gas and oil-fired boilers. The flame produced by a hand-stoked boilers is similar to that in a poorly designed and operated mass fed MSM incinerator. As noted in figure 4-6, the BaP emission rates from gas-, oil and coal-fired boilers with similar flame shapes are generally below 1 g/Mcal .B For comparison with other data in this report 1 g/Mcal is approximately equal to 500 ng/m3 which is on the same order as the PCDD and PCDF emission rates indicated in Tables 3-7 and 3-8 for hospital incinerators. The BaP emission rates from the hand-stoked coal boilers are as much as 5 orders of magnitude above the levels produced by the diffusion flames. These comparisons suggest that the chemical structure of the fuel may have a relatively minor influence on POM emissions but that other parameters related to the manner in which the fuel is burned can have a significant influence. This underlines the fact that combustion controls, through careful incinerator design and operation, have the potential to achieve significant PCDD and PCDF emission reductions. Air Distribution Effects in Controlled Air Incinerators. Using the waste burning process description of Section 3.1.4.1 in conjunction with the equilibrium, chemical kinetic, and fuel composition considerations of this section, it is possible to identify a variety of combustion control approaches for POM, PCDO and PCDF emissions, all based on elimination of CML.027 4-18 890955 S �•y, • Coal ■ Oil • ♦ Gas Emission less than value plotted c 1 Tests on Same Unit m Ca a 10' e 10' - Coal — 0 a a. 10 ' - «♦♦ <♦ <a 5` 10-= I I I I 10' 10' 10' 10' 101° 10" 1012 Gross Heat Input to Furnace, cal/hr Source: Reference 8. Figure 4-6. Benzo(a)Pyrene Emissions from Coal, Oil, and Natural Gas m Heat-Generation Process S 4-19 890955 fuel -rich, low temperature pockets. A discussion of the design or operating conditions which lead to the formation of these pockets follows. Controlled air incinerators will be used for the purpose of discussing air distribution effects on combustion control techniques for control of POM, PCDD, and PCDF. This type unit is chosen because of its wide use in the past 10 to 15 years. Retort incinerators share some similarities with controlled air units because of their two-stage design; this discussion will therefore also have some relevance to retort units. The design and operation of these units will be discussed by combustion stage. primary Combustion. As stated in Section 2.1.2, waste is fed into the primary combustion chamber which is operated with less than the full amount of air required for combustion. The air addition rate is usually 40 to 70 percent of stoichiometric requirements. Under these sub-stoichiometric conditions the waste is dried, heated, and pyrolized, thereby releasing moisture and volatile components. The primary chamber can therefore be considered a large fuel-rich pocket from the standpoint of POM, PCDD and PCDF formation. Conditions for formation of these compounds can, therefore, be considered optimum in the primary stage. Waste is fed to the primary combustion chamber by either manual or mechanical loading devices. Manual loading is done by charging a bag at a time into the primary chamber while most mechanical loaders employ a hopper and ram assembly. Both feed mechanisms are non-continuous feed processes which deliver the feed in a batch-type manner. Therefore, the potential for an extremely fuel-rich system exists when waste is initially charged to the incinerator. A dynamic air supply system which can follow the transient is required if the system is to maintain its stoichiometric set point. Failure to maintain a consistent air-to-fuel ratio will make control in the secondary combustion chamber more difficult. Most incinerators control combustion in the primary combustion chamber by measuring the temperature in the primary chamber and adjusting the air flow rate to that chamber to meet a temperature set-point. When temperatures are too low, air is added to accelerate the burning process. Conversely, the air rate is decreased when the temperature is too high. • CML.027 4-20 890958 In conclusion, the operation of the primary combustion chamber is such that a fuel-rich combustion environment exists. Smooth control of the air-to-fuel ratio is needed to counteract transients due to the feed mechanism; this will minimize the amount of fluctuation in the gas rate and characteristics of the gas entering the secondary combustion chamber. Secondary Combustion. Moisture, volatiles, and combustion gases from the primary chamber flow upward through a connecting section where they are mixed with air prior to entering the secondary combustion chamber. If the gases from the primary chamber are hot enough they will self-ignite when mixed with the secondary chamber air. However, a burner is located near the entrance to the secondary chamber to provide additional heat when it is needed. The air injection rate into the second chamber is generally between 100 and 140 percent of total stoichiometric requirements. Thus, the total combustion process in the incinerator (including both stages) operates at between 40 to 110 percent excess air. . If operation of the secondary air flow is kept at design levels, the amount of oxygen added to the combustion process is sufficient to complete the combustion process without exceeding the lean fuel flammability limits. The critical issue is that the fuel-rich exhaust from the primary chamber must be mixed with air on a molecular level to achieve complete destruction of all POM, PC00 and PCDF, and potential precursors. Simply injecting additional air into the secondary chamber is not sufficient to ensure high combustion efficiencies. Consequently, great care must be taken in designing the secondary air chamber so that complete and thorough mixing will occur. One design approach to increase mixing currently in use is to introduce air at right angles to the flow of primary chamber gases and to use a series of staggered manifolds on either side of the gas. A second design approach is the enlargement of. the secondary combustion chamber. This approach leads to greater residence times at temperature while also increasing the chance for mixing. From an operational standpoint, the primary air flow rate control , secondary airflow rate control , and the extent of mixing in the secondary chamber, all could have a significant impact on POM, PCDD and PCDF emissions. Further research is required to better understand how • incinerator design and operating parameters influence these emissions. CML.027 4-21 690955 Thermal Environment. In EPA's Tier 4 study, it was observed that trends in PCDO and PCDF emissions could be detected based on the combustion temperature.9 It was also noted in this report that NSW incinerators burning high moisture content waste tended to have low combustion temperatures and higher PCDD/PCDF emissions. The following discussion considers the theoretical relationship between temperature and emission rates for PCDDs, PCDFs, and other POMs. Thermal environment and chemical kinetic processes are intimately related to each other. Flame temperature rise is the result of chemically converting fuel to combustion products while the rate of the chemical reactions is exponentially dependent upon the local temperature. In the discussion of equilibrium considerations it was shown that formation of fuel-rich pockets of gas favors production of POM, PCDO and PCDF. In the discussion of kinetic processes, Figure 4-4 showed that substantial hydrocarbons can persist in 80 percent theoretical air mixtures if there is heat extraction. Thus, removing heat from combusting gases tends to increase the stoichiometric ratio at which hydrocarbon species can persist. An important set of variables influencing flame temperature is the excess oxygen level in the combustor and the moisture content of the waste. To illustrate these effects, a series of adiabatic flame temperature calculations were performed as a function of percent theoretical air. To demonstrate that flame temperature is controlled by combustion of waste volatile matter, methane was used as the fuel for these calculations. To simulate the moisture content of the waste,- various quantities of liquid water (0-40 percent) was added to the 'fuel." Results from these calculations are presented in Figure 4-7.10 As shown, increasing the combustion air from 150 to 200 percent of the theoretical requirement decreases the adiabatic flame temperature by approximately 300°C (540°F) . At 150 percent theoretical air (50 percent excess air), increasing the moisture content from 0 to 40 percent decreases the adiabatic flame temperature by approximately 150°C (270°F). • The important operational consideration is to maintain the excess air in a range which is high enough to insure that oxygen is available for fuel burnout but low enough to prevent excessive depression of the flame temperature. The requirement for operation' within an excess air window is CML.027 4-22 Adiabatic Flame Temperatures of CN4/N10(1) - Air Mixtures. To • 29u 2200 OS N20 in O44 SS 2000 302 20f —40S s 1500 I 1600 11400 ! \ 1200 1000 . SO 100 150 200 250 300 Percent Theoretical Air • Source: Reference 10 • Figure 4-7. Variation of Adiabatic Flame Temperature with Percent Theoretical Air and Percent Moisture in the MSW 4-23 1990955 w.— illustrated in Figure 4-8 which shows the measured total hydrocarbons in the exhaust of a highly cooled laboratory furnace as a function of excess air level (see Reference 5) . It should be noted that the data in this figure are hardware-specific and that the acceptable excess air operating window will vary with both incinerator design details and characteristics of the waste being burned (e.g. , heating value, moisture content, and halogen content). The moisture content of hospital waste is dependent on the daily operation of the hospital . As illustrated in Figure 4-7, adjusting the excess air level can offset the thermal influence of large variations in moisture content. The thermal influence of adding 40 weight percent water to the fuel may be offset by decreasing excess air level by about 20 percent. From a combustion control standpoint, hardware could be developed to continuously monitor the exhaust gas H2O content; that data could be used in a control system to appropriately adjust the excess air level . Research is required to define the proper mode of excess air control , but theoretical considerations indicate that it is likely that minimum POM, dioxin and furan emissions control would betac)kiayed_b adjusttag. excess air rates in the primary and secondary chambers to achieve desired temperature levels and gas residence times. An additional operational consideration influencing thermal environment and possibly having a major impact on POM, PCDD and PCDF emissions is the unit start-up and shut-down procedure. Some facilities may have greatly different warm-up periods depending on operator awareness. Based on considerations presented earlier in this section, extensive warm-up using auxiliary fuel (natural gas or distillate oil) is the preferable operating procedure. The start-up period may have little impact on steady-state emission rates but a substantial mass of POM, PCDD and PCDF could be emitted during start-up with cold walls. By the same token, sufficient air and temperature levels should be maintained during burn-down periods to assure complete combustion. Post-Combustion Formation Mechanisms. In addition to formation in fuel-rich pockets of the incinerator combustion zone, it is possible that PCDD and PCDF may be formed by flue gas reactions taking place downstream of the first or second stage combustors. CML.027 4-24 890958 I 4000 — 4 co - t t — t Hydrocarbon O 2000 — tr \41 2 o + \ O CIAO n to -11411 co E • 73 EO CH0, Q• 0.01 — S Cs — c AS S• o ❑ C.H.CI 0. CJ C LL 0.005 - - o ■ I p ttieral IA 50 100 150 200 250 300 Percent Theoretical Air Source: Reference 11 m r. Figure 4-8. Hydrocarbon Breakthrough as a Function of Percent m Theoretical Air S 4-25 pp�p p 89095 Several mechanisms have been hypothesized by various researchers to account for the formation of PCDD and PCDF downstream of the combustion chamber in municipal waste combustors. These hypotheses include a) reaction of products of incomplete combustion, for example, chlorophenols and chlorobenzenes in the gas phase or on the fly ash to form PCDD and PCDD; b) de novo synthesis of PCDD/PCDF on fly ash involving metal chloride catalysis; or c) de novo synthesis from particulate carbon. All of the hypothesized mechanisms include temperature 'windows' for the formation reactions. For example, recent studies of PCDD formation and destruction by Vogg and Steiglitz indicate that formation of PCDD in fly ash can occur at temperatures between approximately 430°F and 750°F (220°C and 400°C), peaking at 570°F (300°C) .12 The authors heated fly ash for two hours and found no change in PCDD/PCDF concentrations below 390°F (200°C), a 10-fold increase at 570°F (300°C) and complete destruction at 1110°F (600°C).13,14 Other researchers have proposed that PCDD/PCDF can be formed from particulate carbon in MWC flue gases at temperatures of about 570°F (300°C).15 $ummarv. The above discussion illustrates that emissions of POM, PCDD and PCDF are either the products of incomplete combustion or are formed by post-combustion mechanisms. A critical component in the combustion formation process is presence of fuel-rich pockets of gas. The primary combustion chamber in a controlled air incinerator is operated as a large fuel-rich pocket. To maximize the extent of combustion, the following steps can be taken: o Control the combustion air supply to the primary chamber to minimize transients in the outlet flow rate and composition; o Proportion combustion air between the primary and secondary chambers to maintain desired temperatures; and o Promote efficient mixing of air and combustion gases in the secondary chamber. Each of these combustion parameters are adjustable during the incinerator design and/or as part of the unit operating procedure. The assertion that combustion-generated PCDD and PCDF emissions can be reduced by combustion control is clear, but the types of modifications likely to be CML.027 4-26 890958 effective will depend upon the specific design and operating conditions of a given model and size. That is, combustion modifications must be tailored to the specific type of incineration hardware under consideration. Appropriate control strategies for existing facilities must be evaluated on a case-by-case basis and some processes may require extensive hardware modification and/or altered operational procedures. To the extent that PCDD/PCDF emissions are formed downstream of the combustion chambers, emission reductions will be influenced by the mechanisms involved and practices employed in this area. If emissions are the result of reactions between products of incomplete combustion (PICs), these products must be avoided in the temperature window in which the reactions occur. Possible emission reduction techniques would be the elimination of PICs in the secondary combustion chamber by operating the chamber at higher temperatures and/or larger gas residence times. Another approach would be to remove the PICs from the flue gas stream either by scrubbing an adsorption. If PCDD/PCDF emissions are the result of de novo synthesis on fly ash or from particulate carbon within a given temperature window, then the removal of fly ash and carbon .t temperatures above the critical window would reduce flue gas emissions. However, it may still be necessary to rapidly quench the captured particles (e.g., with a scrubbing liquid or air) or to cover their active surface area with an inert material (e.g., powdered lime) in order to minimize subsequent de novo synthesis from captured particles. The processes available for such flue gas treatments are discussed in the next section. 4.3 FLUE GAS CONTROLS • Add-on devices may be employed for post-combustion treatment of flue gas. As shown in Section 3.0, two devices presently in use on hospital incinerators are fabric filters (baghouses) and wet scrubbers. Other potential add-on controls not presently in use are dry scrubbers and dry injection. Dry scrubbers and dry injection have demonstrated acid gas and organic emissions control on NSW incinerators and, when coupled with fabric filters, offer good particulate control as well . In addition, after-burners are potential controls for organic compound emissions. These same devices are candidates for control of emissions from hospital waste incinerators. CML.027 4-27 590958 4.3.1 fabric Filters (Baahouses) Fabric filters offer very high efficiencies for particle removal from flue gas with attainable efficiencies greater than 99.9 percent. Currently, there are at least four MSM incinerator installations utilizing baghouses in the U. 5.16 Similar efficiencies would be expected for hospital waste incinerators because of the similar nature of the wastes. At least one baghouse has been installed and operated on a hospital waste combustor (see Section 3.2.2) . Fabric filters rely on porous glass fabric to facilitate removal of very fine PM. Figure 4-9 shows a typical arrangement. Collected PM is 'shaken,' either mechanically or by air, from the bag and disposed of with bottom ash from the incinerator. Some advantages and disadvantages of baghouses are as follows:l7 Advantages 1. High PM removal efficiencies can be obtained. 2. High efficiencies for finer PM means good removal of those metals which concentrate on fine PM. 3. • There are no wastewater disposal. requirements. 4. Variations in flue gas flow rate or chemical Composition do not usually affect fabric filter performance. 5. Submicron particle collection improves as the thickness of the dust layer on the collection surface increases. pisadvantaaes • 1. Fabric filters are designed only for PM control and do little to control gaseous pollutants. 2. High pressure drops may occur if bags become plugged with solids which could lead to large power requirements. 3. The upperotemperature limit of most widely used filter media is about 260"C (500"F). 4. 'Sparklers' (i .e., incandescent waste particles) carried by the flue gas can cause fires in the fabric filter. CML.027 4-28. lI r I ( ( ( Clean Alr Cieas Air Phase I 4Compresssd Alr Dirty Air 4 ((((( it;ex;� "l :NI Paints :aks RaNls Rllters , it le s,. . ■ . ■ ► ■ a . . . ► M Dist Ceaysylag neta►y _yy system oasfar• Figure 4-9. Typical Fabric Filter System 4-29 $9®95S 5. The dew point of the flue gas must be considered. An excursion below the dew point can result in condensation and hence blinding of bags. In addition, due to the typically high HC1 content of hospital waste incinerator flue gases, condensation can lead to the formation of corrosive HC1 acid. 4.3.2 Scrubbers and Dry Iniection Systems Wet scrubbers currently in use offer lower efficiencies for the collection of PM but higher efficiencies for acid gas removal . Wet scrubbers use liquid to remove pollutants from the gas stream. Scrubber design and the type of liquid solution used largely determine contaminant removal efficiencies. Efficiencies for the removal of acid gases with plain water are in the range of 30 percent, while the addition of Ca(OH)2, CaCo3, or Ca0 to the scrubber liquor has been shown to result in efficiencies of 93-96 percent.1S In general , high gas-side pressure drops must be used to obtain high efficiencies for PM control . There are basically three types of wet scrubbers: (1) low energy (spray tower), (2) medium energy (impingement scrubbers such as packed column, baffle plate, and liquid impingement), and (3) high energy (venturi). Low energy scrubbers (spray towers) are usually circular in cross-section (see Figure 4-10) . The liquid is sprayed down the tower as the gases rise. Large particles are removed by impingement on the liquor pool , and finer particles are removed as the flue gas rises through the tower. Low energy scrubbers mainly remove particles in the 5-10 micron • range and larger.19 Medium energy devices mostly rely on impingement to facilitate removal of PM. This can be accomplished through a variety of configurations, two of which are diagrammed in Figures 4-11 and 4-12. • High energy scrubbers use a venturi mechanism for PM removal (see Figure 4-13). The flue gases impinge on the liquor stream in the venturi section. As the gases pass through the orifice, the shearing action atomizes the liquor into fine droplets. As the gas leaves the venturi • CML.027 4-30 890955 Clean Gee Outlet Liquid Distributer #14 , 4LIquer Inlet Dirty Gee Inlet • 'ff.';lllll 111• Liquor Orals • Figure 4-10. Open Spray Tower Scrubber 4-31 890958 Clean Gas Outlet Motorail Getr.laid • • • Droplets ' D• Rntrslss.nt —:--� Gristles Dirty Gas , Inlet —► Find •Orifice }Coest.et-Lsysl.` J� / Liquor Outlet Ririe Nozzle f/ // // Liquor //" t Reservoir �s r Liquor I • Drain J� • Figure 4-11 . Axed Orifice Scrubber 890958 4-32 A Chas Gas Outlet 4,1)/ ) ` ' Os•Sati swast • JJ Ssstlsa Iaplswasst GAMS Plats Statesf R I J Liquor • = -` Islet Nusidirlsatlss • bats, Dirty Gas �/ / sitnaya ialst //// //ft /7/ I. 1 Llgssr ; Orals Figure 4-12. Baffle Impingement Scrubber 4-33 590955 Clsaa G.• Outlet Dirty Gas f Islst1 YIWO Ligon i— Li lals! LI�eN U ` Modernist's. `+ Weir )l Aaasla• f 0s•[ntralAwset Or1tNs Settles Venturi tattles u.... is • Gssbsulatlsa Pa, aad Disposal • Figure 4-13. High Energy Venturi Scrubber 4-34 890958 section it decelerates, resulting in further contact between particles and liquid droplets. The droplets are then removed from the device by the centrifugal action in the de-entrainment section.20 Like baghouses, wet scrubbers offer both advantages and disadvantages. Some of the major advantages and disadvantages of wet scrubbers are:21 Advantages 1. Particle collection and gas absorption can be accomplished simultaneously with proper design. 2. High collection efficiencies can be obtained for any particle size range with sufficient energy input. 3. Viscous materials can be collected without plugging. 4. High temperature gaseous effluent streams can be handled. 5. Moisture content and/or dew point of the effluent gas is not critical to scrubber operation. 6. Heat transfer, chemical reactions, and evaporation are characteristics of wet scrubber operations that can be varied to improve pollutant removal efficiencies. 7.. Capital costs are relatively low. 8. Semi-volatile organic collection, such as dioxins and furans. To remove dioxins/furans, an outlet temperature at near 150"C or below is required. Typic8ll , wet scrubber systems quench flue gases between 150 and 200"C." This magnitude of heat loss should reduce the volatile compounds in the flue gas. 9. Trace semi-volatile metal collection, such as arsenic, chromium, and nickel . In general , metal removal efficiencies of wet scrubber systems vary widely between the 11 trace metals listed in Section 3.1.3. A recent emissions test program conducted at a sewage sludge incinerator has shown wet scrubber removal . efficiencies greater than 95 percent for chromium, arsenic, and nickel . Furthermore, it was shown that 50 percent of the cadmium was scrubbed from the gas stream while an average of 40 percent of the lead was removed. pisadvantaaes • 1. High energy input is required for collection of the finer dust • particles. 2. Corrosion and erosion are characteristic of all wet processing. CML.027 4-35 890958 ir 3. An effluent liquor disposal system is required. 4. Discharge of a water-saturated gas stream can produce a visible steam plume. 5. Re-entrainment of PM may be a problem. 6. Wet scrubbers are not effective for control of insoluble gaseous organics. Dry scrubbers combined with fabric filters applied to MSW incinerators have received considerable attention recently. In these systems, a lime slurry is injected into the scrubber where it contacts the flue gas. The water is evaporated and dry salts result from the reaction of lime with constituents of the flue gas. The salts, unreacted lime, and particulate matter are collected in fabric filters downstream of the reactor. It has been theorized that filter cake build-up provides available reaction sites for continued-reaction with pollutants from the flue gas. Test results from MSW incinerators for dry scrubbing/fabric filter systems show enhanced PM emission reduction in all particle size ranges compared to wet scrubbers operating with even larger pressure drops. Acid gas and metal removal efficiencies have also been high.24-28 Also of interest are the low dioxin/furan emissions from the dry scrubbing system. A diagram of a commercially available dry injection system, the Teller system, is shown in Figure 4-14.29 In this system a dry venturi is located between the dry scrubber (quench reactor) and the baghouse. The dry venturi reportedly causes agglomeration of small particles formed in the dry scrubber which results in reduced pressure drop in the baghouse. This reduced pressure drop translates to longer cleaning cycles which are associated with higher removal efficiencies for small particles. The Teller system employs a lime slurry in the quench reactor for acid gas absorption and a proprietory dry crystalline product (called Tesisorb) in the dry venturi to promote capture and agglomeration of sub-micron particles. Other dry injection systems applied to MSW incinerators utilize only pulverized lime injected into the flue gas stream in. a dry venturi upstream of a baghouse. CML.027 4-36 890958 I f) 73.1141 • t E I a a:1 0 N as sas C s s s • 2 8. • al ow a • 7. a 1 .i. • m m H ... . al U ii 4 Y _Li m 'u. I V ftl".>imerg 1 a it I N • = el NI C CO O O .r al Q a O Y cn 4-37 89+x'958 IIMIIIIaIIIIIIIIMAdvantages cited for dry scrubbing/infection followed by fabric 4.4 filtration include the following: 1, (1) Insensitive to changes in inlet particulate loading or characteristics within the combustion chamber. (2) Effective and efficient particle capture in the submicron range. ' 2 (3) Efficient SO2 and HC1 removal . 3. (4) Produces dry particulates that can easily be disposed. (5) Because flue gas is not saturated with moisture, there is less 4 potential for a visible plume exiting the stack. (6) Reduction of organic emissions due to low operating temperatures. 5. Disadvantages cited include the following: (1) Reduced exit gas temperatures can affect gas plume rise, thus affecting pollutant dispersion. 6. (2) Reagents costs are high. Afterburners A third combustion chamber on some incinerators acts as an afterburner.This control device can be expected to further reduce organic emissions. 7.The most likely location for such a device would be before the scrubber. Direct flame afterburners operating at a 2,000°F temperature 8. ond residence time can typically achieve greater than 98 percent destruction even for chlorinated organics." 9. 10. 11. 12. 13. CML.027 890958 CML. 4-38 4.4 REFERENCES 1. Cooper, M. J: , Foster Wheeler USA, Corp. The State-of-the-Art MSW Facility at Commerce, California. Presented at the Air Pollution Central Association Conference on Incineration of Wastes. Wakefield, Massachusetts. April 12-13, 1988. 2. Haynes, B. S. , M. Neville, R. J. Quann, and A. F. Sarofim, J. Colloid. Interface Sci . , 87, 266-278 (1982) 3. Stull , R. D. , E. F. Westrum, and G. C. Sinke: The Chemical Thermodynamics of Organic Compounds, Wiley (1969) . 4. Shih, C. C. , R. F. Tobias, J. F. Clausen, and R. J. Johnson: Thermal Degradation of Military Standard Pesticide Formulations, TRW Report 24768-6018RU-00, U. S. Army Medical R&D Command, (December 1974) . 5. Kramlich, J. C. , W. D. Clark, W. R. Seeker, and G. S. Samuelsen, Theoretical Evaluation of Exhaust Emissions of CO and THC as Indicators of Incineration Performance, Final Report, Work Assignment 3, EPA Contract No. 68-02-3113, 1984. 6. England, G. C. , M. P. Heap, D. W. Pershing, J. L. Tomlinson, and T. L. Corley, "Low-NO Combustors for High Nitrogen Liquid Fuels," Proceedings of the Jofnt Symposium on Stationary Combustion of NO Control . Vol . V, Fundamental Combustion Research and Advanced - x Processes. EPA Report No. IERF-RTP-1087a, 1980: 7. Shaub, W. M. and W. Tsand, "Dioxin Formation in Incinerators," Environ. $ci . Technol . , 17, 1983, pp. 721-730. 8. National Environmental Research Center, 'Scientific and Technical Assessment Report on Particulate Polycyclic Organic Matter (PPOM) ," EPA-600/6-74-001, March 1984. 9. Miles, A. J. , et. al . Radian Corporation. Draft Engineering Analysis Report, National Dioxin Study, Tier 4: Combustion Sources. EPA Contract No. 68-02-3889, Work Assignment No. 40. November 1985. 10. Final report. 'Municipal Waste Combustion Study Data Gathering Phase," prepared for Morrison, R., EPA, by Radian Corporation, November 1986. 11. Reference 5. 12. Stieglitz, L. and H. Vogg. 'New Aspects of PC00/PCDF Formation in Incineration Processes." Preliminary Proceedings. Municipal Waste Incineration, October 1-2, 1987, Montreal , Quebec. 13. Clark, M. 'Air Pollution Control Status Report.' Waste Age. November 1987. p. 102-117. CML.027 4-39 Cp 89095© • 14. Hagenmaier, H. , M. Kraft, H. Brunner, and R. Haag. 'Catalytic Effects of Fly Ash from Waste Incineration Facilities on the Formation and Decomposition of Polychlorinated Dibenzo-p-dioxins and Polychlorinated Dibenzofurans.' Environmental Science adn Technology, November 1987, Vol . 21, No. 11, p. 1080-1084 15. Vogg, H. and L. Stieglitz. Chemosohere. 1986. Vol . 15, p. 1373. 16. California Air Resources Board. Air Pollution Control at Resource Recovery Facilities. May 24, 1984. 17. Devitt, T. W., et al . PEDCo Environmental , Inc. Air Pollution Emissions and Control Technology for Waste-As-Fuel Processes. October 1979. 18. Reference 5. 19. Reference 16. 20. Reference 16. 21. Reference 16. 22. Sedman, C. B., T. G. Brna. Municipal Waste Combustion Study: Flue Gas Cleaning Technology. EPA/530-SW-87-021d. U. S. Environmental Protection Agency, Research Triangle Park, NC. June 1987. 23. Radian Corporation, Site 4 Draft Final Emission Test Report - Sewage Sludge Test Program, Work Assignment No. 71, EPA Contract 68-02-6999. 1988 24. Cleverly, D. H. Emissions and Emission Control in Resource Recovery. Office of Resource Recovery, NYC Department of Sanitation. December 9, 1982. 25. Teller, A. J. Dry System Emission Control for Municipal Incinerators. Proceedings of National Waste Conference, 1980. ASME. New York, as cited in Reference 109. 26. Teller, A. J. The Landmark Framingham, Massachusetts Incinerator, presented at The Hazardous Materials Management Conference, Philadelphia, Pennsylvania. June 5-7, 1984. 27. Teller, A. J. New Systems for Municipal Incineration Control . National• Waste Processing Conference, 1978. ASME. , as cited in . Reference 109. CML.027 4-40 890958 28. Teller, A. J. Teller Systems Incineration - Resource Recovery Flue Gas Emission Control . Presented at Acid Gas and Dioxin Control for Waste to Energy Facilities. Washington, D.C. November 25-26, 1985. 29. Reference 28. 30. U. S. Environmental Protection Agency. federal Resister 48:48932.1983. • CML.027 4-41 890958 Hello