Deactivation of hazardous chemical wastes Alternatives to conventional incineration and biological degradation include chemical conversion, stabilization, and processes for removing hazardous constituents
Samuel P. 'hcker National Institute for Occupational Safety and Health Cincimri, Ohio 45226 George A. Carson National Institute for Occupational Safety and Health Kansas City, Mo. 64106 In 1980 approximately 57 million metric tons of nonradioactive hazardous waste was generated by manUfaCturhg industries in the U.S.,according to an EPA estimate (I). It is expected that the annual quantity of hazardous wastes generated by these industries will increase at a rate of 3.5% per year and will total more than 67 million metric tons by 1985 (2). Approximately four million metric tons of radioactive waste from nongovernment origins was generated in 1970. Data on the quantity of radioactive waste generated by the government are not available (3). Hazardous waste is disposed of by many different methods. The most common method has been placement into drums and transportation to dump sites for burial. Other methcds include pooling for evaporation, placement into lined disposal sites, deepwell injection, spraying into the ground and mixing with the soil, and incineration. Recently, the scientific community has been conducting research into ways to deactivate hazardous wastes in order that the wastes can be reused, converted into less hazardous materials, or stabilized so that they do not represent a threat to workers or the environment. A hazardous chemical waste may be toxic, reactive, corrosive, or radioactive. A toxic waste is harmful to human or other forms of life; it may he carcinogenic, mutagenic, or teratogenic; and it may cause death. A reactive hazardous waste may be explosive, may form a dangerous mixture with water, or may undergo chemical change without addition of another substance to form a toxic product. An ignitable waste may be a fire hazard. A waste is considered This article not subjed lo U.S copyright. Published 1985 American Chemical Society
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corrosive if it is aqueous and has a pH of 2 or less or 12.5 or more, or if it is a liquid that erodes steel at more than 6.35 mm per year at 55 OC. More information about toxicity, reactivity, ignitability, and corrosiveness can be found in the Federal Register (4). Methods of deactivating hazardous chemical wastes can reduce the exposures of workers to such wastes, ease storage problems prior to disposal of waste products, and permit recovery of useful substances. There is a vast amount of information on deactivation in the recent literature; excluding information on the incineration and biological degradation methods of chemical conversion from the literature review has made preparation of this report more manageable. Deactivation by chemical conversion is a process by which a waste or constituent of the waste is transformed to at least one substance that is less hazardous than and chemically different from the original material. Generally, methods of removing hazardous constituents can be used for concentrating the hazardous constituents and reducing the volume of hazardous waste. Stabilization is a process by which the waste is fixed in cement or other material, is treated to form a hardened material, or is encapsulated in an inert substance. Chemical conversion Many wastes that can be chemically converted to less hazardous products are organic compounds (Table I). But inorganic chromium(VI), also included in Table I, can be present in possibly carcinogeniccompounds and can be reduced with formaldehyde to chromium@), which may be a less hazardous product (5-7). However, the recently reported hazardous effects of formaldehyde exposure may make this method unattractive. Sulfur dioxide is among the agents most commonly used to reduce chromium(V1) to chromium(1II). The chromium(II1) can be precipitated as chromic hydroxide by the addition of sodium hydroxide (s). Wet oxidation is the process by which compounds in water are destroyed by oxidation at temperatures between 175 OC and 345 OC and pressures usually between 20.4 and 204 atmospheres (9, 10). Oxygen is supplied by a gas (ordinarily air) that is bubbled through the aqueous phase. The oxidation is exothermic, and the heat released helps to reduce the amount of fuel required to maintain the reaction temperature. Oxidation products include carbon dioxide and biodegradable alcohols, ketones, aldehydes, and carboxylic acids. Chloride is a product from chlorinated hydrocarbons. Sulfate is a product from 216
Environ. Sci. Twhnol.. MI. 19. No. 3. 1985
TABLE 1
Chemical conversion processes for hazardous wastes P,DcE.SS
%=le lype
Wet oxidation
Variety of organic compounds Phenols, cyanides. and organic lead compounds in wastewaters. compounds in air Variety of organic compounds Cyanate, thiocyanate, acetate. phenols, cresols Chromium(V1). cyanide ion, met+ cyanide complexes Chlorinated organic compounds in wastewaters Polychlorinated hydrocarbons Polychlorinated organic compounds Pesticides, polychlorinated biphenyls
Ozonation Molten-salt combustion Electrochemical oxidation Treatment with formaldehyde Catalytic reduction with metal powder Catalytic hydrogenation Dechlorination Destruction by microwave plasma Hydrolysis Neutralization
sulfur compounds, such as mercaptans. Wet oxidation is useful for treatment of wastewater. Generally, the use of a catalyst for wet oxidation will effect a greater degree of destruction at the same temperature in a given period. Cupric ion is effective as a homogeneous catalyst for a large variety of organic compounds. At an initial concentration of 5.0 glL, 82% of pentachlorophenol can be destroyed in l h at 275 'C; however, 97.3% of pentachlorophenol is destroyed in the presence of cupric ion in 1 hat 275 OC (9). Many organic compounds can be destroyed efficiently by wet oxidation without a catalyst. More than 99.8% of each of the following compounds at initial concentrations of 5.0-12.4 glL can be destroyed in 1 h at 320 OC: phenol; 2-chlorophenol; pentachlorophenol; 2,4-dimethylphenol; 4-nitrophenol; acrolein; 2.4-dinitrotoluene; 1,2-diphenylhydrazine; acenaphthene; and acrylonitrile. Toxicities of the final solutions were lowered when determined with Daphnia m g n a (9). Waste treatment by ozonation involves ozone, a very strong oxidizing agent. The oxidizing power of ozone is sufficient to destroy carbon-carbon bonds and aromatic rings. Phenol can be oxidized by ozone to form oxalic acid. An organic compound can be oxidized to carbon dioxide and water if the quantity of ozone is sufficient. Because ozone is very unstable, it must be produced on site for immediate use (10). Ozone can be generated by electrical discharge through air or oxygen (11). Well-established applications of ozonation include treatment of wastewaters containing phenols and cyanides and oxidation of compounds in air to
Organophosphorus pesticides, carbamate pesticides Strong acids, alkalies
solve odor problems. The concentration of phenol in wastewater can be reduced from 0.4 mglL to 0.01 mg/L by using 20-40 mg ozone per liter of water (11). The electroplating industry is a major source of wastewaters that contain cyanide. Concentrationsof copper, nickel, and zinc cyanides can be reduced to levels below detection limits by ozonation (5).Ozonation has been used to reduce odors in sewage treatment plants, rendering plants, the paint industry, and the plastics industry (11). It is not economical to oxidize cyanide by ozonation beyond the cyanate stage (5).Cyanate can be converted to bicarbonate and nitrogen gas with chlorine under alkaline conditions. However, chlorine can be used for oxidation of cyanide itself to bicarbonate and nitrogen (8). Ozonation also can be used for transforming organic compounds of lead in wastewater to oxides that are insoluble and can be collected by filtration. Concentrations of alkyl lead in wastewater can be reduced to levels below 5 ppm by this process. Wastewater that contains soluble lead compounds is produced in the sodium-lead alloy process for the manufacture of tetraalkyl lead (12). During 50 h of ozonation, 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8TCDD) as a suspension in carbon tetrachloride and water can be destroyed with an efficiency of 97%. 2,3,7,8TCDD is among the most toxic compounds known and is thought to be the most poisonous dioxin. Chlorodioxins have been detected in various polychlorinated phenols, such as 2,4,5-trichlorophenol and pentachlorophenol, which are important industrial compounds (13, 14). Among the dioxin-containing
-
T
Dumping of hazardous wastes has been replaced bv safer methods of disposal
waste products are tars, slurries, and anhydrous liquids from the manufacture of 2,4,5-uichlorophenol (14). The use of ultraviolet radiation during ozonation causes higher reaction rates and reduces the quantities of ozone required for destruction of compounds. Ultraviolet light increases reactivities of ozone and various compounds by exciting electrons of the molecules to higher levels of energy. Reaction pathways for ozonation include oxidation and photochemical decomposition (5). Molten-salt combustion is a process by which hazardous materials can be oxidized below the surface of a salt or salt mixture in the molten state. Molten sodium carbonate and a molten mixture of sodium carbonate and sodium sulfate (90:10, w/w) have teen used. Operating temperatures range from SO0 OC to loo0 OC. The hazardous materials and air are fed into the combustion chamber below the surface of the melt. Generally, the heat produced during oxidation is adequate for maintaining the salt or salts in the molten state. Oxidation products include carbon dioxide and steam. Hydrochloricacid and sulfur dioxide, which form during the oxidation of chlorine- and sulfur-bearing compounds, react with sodium carbonate. The following substances have been destroyed with efficiencies greater than 99.9% by the molten-salt combustion process: DDT 11, I-bis(chloropheny1)2,2,2-trichloroethane], Malathion, chlordane, and mustard gas [bisQ-chloroethyl)sulfide] (15, 16). Electrochemical oxidation can be used for destruction of cyanide, cyanates, thiocyanates, acetate, phenols,
be used as solvents. PCBs can be reduced stepwise to biphenyl. DDE [ l , l bis(chlorophenyl)-2,2-dichloroethylene], which can be formed easily from DDT by treatment with sodium hydroxide in ethanol, can be converted to 1,ldiphenylethane. It is difficult to remove all chlorine atoms by this process from molecules of aldrin and dieldrin, which are nondanar and bridged moletules (20). In addition to PCBs. other uolvchlorinated compounds, such as &n&chlcrophenol, DDT, and Kepne, can be dechlorinated efficiently and rapidly with a mixture prepared from molten sodium metal and polyethylene glycol in the presence of air or oxygen. Sodium chloride is a by-product of the process. In the case of PCBs, polyhydroxy biphenyls and hydroxy benzenes are reaction products. The sodium mixture used for dechlorinationcan be prepared at temperatures above 9 7 T , stored for lone wriods. and heated prior to use (217. . Various oesticides and PCBs can be degraded Gith high efficiency by the microwave plasma process when oxygen is used as the reactant gas (22,23). The plasma consists of ions, free electrons and neutral species. Highly energized electrons dissociate molecular oxygen into atomic oxygen, which can react rapidly with organic compounds. Also, organic molecules undergo dissociation into free radicals during bombardment with free electrons. These free radicals can react rapidly with oxygen. Malathion, Aroclor 1242, Aroclor 1254, phenylmercuric acetate, and Kepone have been degraded with efficiencies greater than 99%. Reaction products for these substrates include carbon dioxide, carbon monoxide, and water vapor. Other reaction products for these substrates are sulfur, sulfur dioxide, metaphosphoric acid, hydrogen chloride, and mercury. Generally, organophosphorus pesticides and carbamate pesticides can be degraded by hydrolysis under alkaline conditions. Malathion, parathion, methyl parathion, DDVP (2,Z-dichlorovinyl dimethyl phosphate), and carbaryl have been degraded by alkaline hydrolysis. Dimethoate, another organophosphorus pesticide, can be destroyed by alkaline hydrolysis, but the toxicity of mercaptoacetic acid, one of the reaction products, is almost as great as that of dimethoate itself (24). Captan, an imide used in treating seed corn, can be hydrolyzed with 0.5 N NaOH solution that contains 0.05% household laundry detergent. The detergent aids in the dissolution and removal of captan from the corn. Captan protects seed corn from fungal growth
and cresols. However, this process is inefficient at low concentrations because mass transfer is poor. For example, it is possible to reduce concentrations of cyanide to 5 ppm by electrochemical oxidation, but the process is inefficient at levels below ppm (17). Formaldehyde has potential for treatment of hazardous wastes. Under acidic conditions, formaldehyde can reduce chromium(V1) in tannery and electroplating wastes to chromium@). Carbon dioxide is a by-product of the reaction. Formaldehyde in basic solution can convert free cyanide to substituted acetates. Copper and silver in cyanide complexes in electroplating wastes can be recovered as free metals after reduction with formaldehyde. Zinc and cadmium in cyanide complexes can be recovered in oxide form as precipitates after treatment of the complexes with formaldehyde (6). Organic compounds in industrial wastewaters can be reduced at room temperature with aluminum, iron, and zinc powders, which are catalytically activated. Chlorobenzene can be reduced to cyclohexanol. Trichloroethylene and tetrachloroethylene at concentrations of approximately 250 pg/L can be reduced until levels are below 5 pg/ L. Other compounds that can be reduced with metal powders are polychlorinated biphenyls, chlordane, Kepone, atrazine, and N-nitrosodimethylamine (18, 19). Polychlorinated hydrocarbons can be reduced to less toxic products by hydrogenation with nickel and palladium catalysts at elevated temperatures and pressures, and xylene and ethanol can
Environ. Sci. Technol., Vol. 19. NO.3. 1985 217
but has caused a problem in disposal of leftover corn (25). Neutralization of acidic and alkaline wastewaters is camed out by the addition of appropriate agents and mixing until the pH is at or near 7. Agents for neutralizing acidic wastewaters include sodium hydroxide, calcium oxide, magnesium oxide, and magnesium carbonate. The problem of calcium sulfate precipitation can be avoided by neutralizing wastewaters containing sulfuric acid with either sodium hydroxide or a magnesium compound instead of a calcium compound. Hydrochloric acid and sulfuric acid are used for neutralizing alkaline wastewaters. Neutralimtion of acidic wastes with alkaline wastes and vice versa can be economically attractive processes (la).
Removal of hazardous constituents Processes for removal of hazardous constituents are applicable to wastewaters that contain ionic species, colloidal particles, and a wide variety of compounds Fable 2). The process of adsorption on carbon is applicable to wastewaters and polluted air. These processes are beneficial for reducing the volume of hazardous waste, and in some cases can be used for recovery of useful substances. m a t e d waters may be suitable for reuse in industrial processes and can be discharged safely to the sewer system if removal efficiencies are high enough. Hazardous constituents of no commercial value that are removed may be disposed of in burial sites after they are stabilized. Adsorption on activated carbon is a method for concentrating a wide variety of compounds in wastewaters and air streams (5. 10). The high capacity of activated carbon for many compounds is attributable to the large surface area of the carbon (500-1500 m2/ 8). The capacity of the activated carbon to adsorb a compound in aqueous solution increases as the solubility of the
compound in water decreases. Generally, strong electrolytes are not adsorbed well by carbon. Although an increase in temperature will cause a decrease in adsorption capacity, it may increase the adsorption rate in aqueous solution. Organic and inorganic compounds can be adsorbed on carbon. Chromium and cyanide compounds from electroplating wastewaters can be adsorbed. Maneb, a pesticide that contains manganese, and the decomposition products ethylene thiourea (ETU) and ethylene thiuram monosulfide (ETM) can be removed from manufacturing wastewaters by filtration through a column of granular activated carbon, but MSMA (monosodium methanearsonic acid), another pesticide, is not removed effectively from wastewater by this method (26). Air pollution control devices sometimes contain beds of activated charcoal for collecting organic solvent vapors in air streams. In many cases, reactivation of carbon and recovery of organic compounds from carbon can be accomplished by thermal desorption. Ion-exchange columns are efficient for removing many different ions from aqueous solution. The ions exchanged may be either anionic or cationic. The elements that can be removed by ion exchange include chromium, cadmium, arsenic, gold, copper, lead, nickel, silver, and zinc. Cyanide ion and radioisotopes also can be removed using this method (5.27, 28). Attractive features of the ionexchange process include the ease of regenerating the ionexchange resins and use of the process for recovery of metals. The ion-exchange process is used extensively in the metal plating industry (29). Levels of arsenic in washing solutions used in the manufacture of sulfuric acid can be reduced substantially by ion exchange (30). Because of the conditions of equilibrium, ionexchange resins may be less efficient for ion re-
TABLE 2
Processes for removal of hazardous constituents Promu
Halardour connltuenls
Adsorption on carbon
Wide variety of compounds in wastewaters and air Ions in wastewaters Metal ions in wastewaters Heavy-metal cations. certain anions in wastewaters Organic compounds, metal ions Colloidal particles, large molecules in liquids Most solute molecules, ions in wastewaters Metal ions
Ion exchange Cementation Precipitation Liquid-liquid extraction Ultrafiltration Reverse osmosis Electrolytic reduction
218 Emiron. Scl.Technol.. MI. 19. NO.3,1985
moval in batch processes than in processes in which solutions pass through columns of the resins. But particular aluminosilicates can be used efficiently to reduce levels of cadmium ions in plating wastewaters to less than 0.1 ppm by a batch process in which ion exchange is important (31). Cementation is the process by which metal ions are reduced electrochemically by a metal with a more negative reduction potential. Chromium(V1). for example, can be reduced with scrap iron (5). Copper can be removed from electroplating wastewater by cementation with powdered iron. A large surface area of iron and a pH below 7 are favorable for this process (32). Copper and cadmium ions in water can be reduced to the free metals with powdered zinc (33). Precipitation is effective for removing many heavy-metal cations and certain anions from wastewaters. Metal precipitates can be in hydroxide or sultide forms. Separation of solids from wastewaters after precipitation can involve sedimentation, centrifugation, or filtration. If the precipitates consist of fine particles, collection of the solids could be slow and inefficient. Collection of precipitates can be facilitated by the addition of coagulants, which increase particle sizes, and flocculants, which connect particles. The most commonly used method of precipitation is the addition of lime (calcium oxide) to the wastewater. Calcium oxide in water forms calcium hydroxide. Although sodium hydroxide can be used for removing metal ions by precipitation, calcium hydroxide can remove sulfate, fluoride, phosphate, and arsenate ions, in addition to the metal ions, by precipitation. The calcium compounds that can be formed with these anions are less soluble than the corresponding sodium compounds (34). If these anions are not removed, they can form complexes with metal ions, and a smaller number of metal ions will be available for removal by precipitation with hydroxide (35). Ammonia, cyanide ions, tartrate ions, and ions formed from ethylenediaminetetraacetic acid (EDTA) can form complexes with metal ions and cause removal problems. Levels of cadmium, chromium(III), copper, iron, and zinc ions can be reduced to below 1 mg/L by hydroxide precipitation, clarification, and filtration. Removal of metal ions can be made more efficient by using sulfide precipitation than by using hydroxide precipitation because most metal sulfides are less soluble than the corresponding metal hydroxides at pH levels above 7. Also, sulfide precipitation can take place in the pres-
ence of most complexing agents. Agents for sulfide precipitation include sodium sulfide and ferrous sulfide (36). Sulfide and ferrous ions can reduce chromium(V1) to chromium(II1). Precipitation of chromium(II1) hydroxide then takes place if the pH is above 7
0. Waste treatment processes can use liquid-liquid or solvent extraction for removal of hazardous and, perhaps, useful substances. A solution of trioctylphosphine oxide in undecane can be used for extracting acetic acid and formic acid from the exhausted liquor that remains after the treatment of wood with a bisulfite solution (37). Metal ions can be removed from wastewaters by liquid-liquid extraction processes involving ion exchange. Barium ions can be removed from wastewater by treatment with a solution of dinonylnaphthalenesulfonic acid in heptane (38). Solvent extraction is a step in a special process for convening sludges to very dry solids (39). With this process, water and oils can be removed from sludges by extraction with an aliphatic amine and separation of the solids from the liquid. The amine solution separates into organic and aqueous phases upon being heated, and the amine can be recovered and recycled. Ultrafiltration of liquids removes colloidal particles and molecules with molecular weights in the approximate range of 500-1,000,000. The type of species retained by membranes for ultrafiltration depends on the characteristics of the membranes. The membrane pore sizes are in the range of 0.00050.006 &m. Some membranes are prepared from hydrophobic, polymeric materials; others are prepared from hydrophilic polymers. Clogging of membranes can be reduced by the selection of appropriate membranes. Commercial applications
of ultrafiltration include rejuvenation of electrocoat paint and treatment of oilwater emulsions from the rolling, drawing, and machining of metal. Processes under development include those involving treatment of waste from industrial laundries, pulp mills, and textile InanUfaCturing (5, lo). In reverse osmosis (RO) solvent passes through a semipermeable membrane from a solution under pressure to a more dilute solution or to a solvent free of solute molecules. Membranes for RO, which have pore sizes in the 0.0002-pm range, are not permeable to most solute molecules and ions. Most membranes for RO are made of cellulose acetate. Treatment of liquid wastes prior to RO may be required to help reduce degradation of the membranes by scales and organic films. This process has been used for treatment of sulfite wastewaters in the paper industry and for treatment of electroplating rinse waters (IO,40). Metals can be recovered by electrclytic reduction. The most prevalent use of metal recovery by electrolytic reduction is in the copper industry. Copper ions in pickling solutions are reduced electrolytically to metallic copper (1 7). Lead in battery sludges, zinc in wastewater treatment sludges, and silver in spent photographic fixing baths can be recovered by processes involving electrolytic reduction (41-43). Stabilization Stabilization, or fixation, is a means of treating sludges, particulate matter, liquids, and radioactive wastes prior to final disposal. Many methods of stabilization can be classified according to the seven categories in Table 3. Benefits of stabilizing hazardous chemical wastes include improving the physical properties of the wastes for easier handling; safer transport and easier burial;
TABLE 3
Methods and applicationsof stabilization Stablllutlon mslhcd
Appllcallon
Solidification with cement
Sludges, contaminated soil, various metal salts, low-level radioactive waste Flue gas desulfurization wastes. other inorganic wastes Radioactive wastes
Solidificationby lime-based processes Solidification with thermoplastic materials
Solidification with organic polymers Encapsulation Solid/ficationby self-cementation Vitrification
Sludges, radioactive sludges Sludges. liauids. particulate maner Fluegas desulfurization wastes, other wastes with large proportions of calcium sulfate or calcium sulfite Extremely hazardous wastes, radioactive wastes
detoxifying various wastes for the protection of workers; preventing pollution of the environment caused by leaching and evaporation of hazardous constituents; and recycling into construction material (4-47). Solidification with cement generally is accomplished with a portland cement and other additives. The quantity of cement can be varied according to the amount of moisture in the waste. Heavy-metal cations in the waste form insoluble carbonates and hydroxides at the high pH of the mixture. The surface of the hardened mass can be coated with asphalt or other material to reduce leaching of hazardous components. Lime-based processes for solidification use reactions of lime with water and pozzolanic (siliceous) materials, such as fly ash or dust from cement kilns, to form a concrete, called a pozzolanic concrete. Thermoplastic materials for solidification, such as bitumen, polyethylene, and paraffin, are mixed with dried wastes at elevated temperatures. The mixtures solidify when they cool. The hardened mixtures may be placed into containers prior to disposal. One group of materials not suitable for this process, however, includes organic wastes that can dissolve the thermoplastic matrix and thus prevent solidification. Chlorates, perchlorates, and nitrates in high concentrations can deteriorate bitumen. Methods of solidification with organic polymers involve the addition and thorough mixing of monomers, such as urea and formaldehyde, with the wastes. A polymerization catalyst can be added. The mixtures can be placed in containers prior to disposal. Methods of encapsulation involve covering the wastes with inert and impervious coatings or jackets, which will prevent leaching. Metal drums of 208L (55-gal) capacity, which can become corroded by hazardous wastes, can be encapsulated with polyethylene jackets (48). Methods of solidification by self-cementation are applicable to wastes that contain large amounts of calcium sulfate or calcium sulfite. A small quantity of the waste is dried, calcined, and added to the rest of the waste with other additives to form a hardened mass. Vitrification involves the heating of a mixture of waste and silica to form a glass. Extremely hazardous wastes and radioactive wastes can be immobilized by this method. mpeets A varied group of industrial, academic, and government organizations Environ. Sci. Technol.. Vol. 19. NO. 3.1985 219
has conducted research to develop or implement a number of methods to deactivate hazardous chemical wastes. Deactivation offers many advantages to the industrial community including lowered exposure to workers, decreased need for storage, lower handling and transportation costs, and, most important, a smaller impact on the total environment. Additional research is needed in the area of deactivation, with the goal of developing a complete list of processes that can be used to deactivate a growing number of hazardous waste chemicals.
Acknowledgment Before publication. this article w a s read for suitability a s a n ES&T feature by Maurice V. Kennedy, Mississippi State University, Mississippi S t a t e , Miss. 39762, and C. F! Huang, University of Delaware, Newark, Del. 19716.
References ( I ) Wilkes, A,; Kiefer, 1.; Levine, B. “Everybady’s Problem: Hazardous Waste,” SW826; U.S. EPA: Washington, D.C., 1980. (2) Worthy. W. Chem. Enx. News 1982, win),10-16. (3) Cheremisinaff, N. P et al. “Industrial and Hazardous Wastes Impoundment”; Ann Arbor Science: Ann Arbor, Mich.. 1979; p. 25. (4) Fcd. Repisf. 1980,45(98). 33121-22. (5) Cherry. K. E “Plating Waste Treatment”: Ann Arbor Science: Ann Arbor. Mich.. 1982. (6) Turnik. F. S. In “Industrial Waste Proceedings of the Thirteenth Mid-Atlantic Conference”; Huang, C. P. Ed.; Ann Arbor Science: Ann Arbor, Mich., 1981; pp. 416-26. (7) “Criteria for a Recommended Standard. . . . Occupational Exposure to Chromium(Vl),” HEW Publication (NIOSH) 76129; U S . Department of Health. Education. and Welfare. Public Health Service. Center for Disease Control: Cincinnati, Ohio. 1975. (8) Pekin, T.; Gagnon, A. P In “Industrial Waste Proceedings of the Thirteenth MidAtlantic Conference”; Huang, C. P, Ed.; Ann Arbor Science: Ann Arbor. Mich.. 1981; pp. 115-26. (9) Randall. T. L. In “Industrial Waste Proceedings of the Thirteenth Mid-Atlantic Canierence”; Huang, C. F!, Ed.; Ann Arbor Science: Ann Arbor, Mich.. 1981; pp. 501-8. (10) Kiang, Y.-H.; Metry. A. A. “Hazardous Waste Processing Technology”; Ann Arbor Science: Ann Arbor. Mich., 1982. ( I I ) Vlahakis, J. I n “Eleetrotechnology: Volume I , Wastewater Treatment and Separation Methods”; Ouellette, R. P; King, J. A,; Cheremisinoii, P N., Eds.; Ann Arbor Science: Ann Arbor, Mich., 1978; pp. 139-92. (12) Fong, C. V.; Konr, I . ; Walker. P I n “Organic Chemicals Manufacturing Hazards”; Goldfarb. A. S . et al.. Eds.; Ann Arbor Scie n t ~Ann Arbor, Mich.. 1981; pp. 195-
(14) Esksito. M. P: Tiernan, T.O.; Dryden. F. E. “Dioxins,” EPA-60312-80-197; U.S. EPA: Cincinnati, Ohio. 1980. (15) Yosim. S.J.; Barclay, K. M.; Grantham. L. F. In ”Disposal and Decontamination of Pesticides”; Kennedy, M. V., Ed.; ACS 220 Enviran. Sci. Technol.. MI. 19. No. 3. 1985
Symposium Series 73, American Chemical Suciety: Washington, D.C.. 1978; pp. 1 IS30. (16) Yosim, S.J. et al. “Safe Handling of Chemical Carcinogens. Mutagens, Teratogens and Highly Toxic Substances”; Walters. D. B., Ed.; Ann Arbor Science: Ann Arbor. Mich.. 1 9 8 0 Vol. 2. pp. 617-33. (17) Vlahakis. I . ; Ouellette, R. P I n “Electrotechnology: Volume I , Wastewater Treatment and Separation Methods”; Ouellette, R. P; King, I. A,; Cheremirinoff. P N., Eds.: Ann Arbor Science: Ann Arbor. Mich., 1978; pp. 193-237. (18) Sweeny. K. H. AlChE Symp. Se,: 1981, 77(209). 67-71; Chem. Ahrrr 1982, 96. 57209m. (19) Sweeny, K. H. AlChE Symp. Se,: 1981, 77(209), 72-78: Chem. Ahsrr 1982, 96. 572 1Oe. (20) Kranich. W. L. et al. “Disposal and Decontamination of Pesticides”: Kennedy. M. V., Ed.; ACS Symposium Series 73. American Chemical Society: Washington. D.C., 1978; pp. 24-34. (21) Pytlewski, L. L. et al. I n ”Treatment of Hazardous Waste. Proceedings of the 6th Annual Research Symposium.’’ EPA-6001980-011; U.S. EPA: Cincinnati. Ohio, 1980; pp. 72-76. (22) Bailin, L. J.; Hertiler, B. L.: Oberacker, D. A. In “Disposal and Decontamination of Pesticides”; Kennedy, M. V.. Ed.; ACS Symposium Series 73, American Chemical Society: Washington, D.C.. 1978; pp. 4972. (23) DeZearn. M. B.; Oberacker, D. A. In “Safe Handling of Chemical Carcinogens. Mutagens, Teratogens and Highly Toxic Substances”; Walters, D. B., Ed.; Ann Arbor Science: Ann Arbor. Mich.. 1980: Vol. 2, pp. 595-615. (24) “Disposal of Dilute Pesticide Solutions.” Report SW-174c; Prepared by SCS Engineers for the U.S. EPA: Washington. D.C.. ,070
, Dihm. P A . In “Trrstmmt of Hamdous Waste. Proceedings o i the 6th Annual Re\esrch Svmootium.” EPA.hIX1 9. 80-01I ; US. EPA:2Cincinnati, Ohio, 19x0; pp. 94-100. (26) Little, L. W. et al. “Treatment Technology for Pesticide Manufacturing Effluents: Atrazine. Maneb, MSMA, and Oryzalin.” EPA-60012-80-043; U S EPA: Research TrianglePark, N.C., 1980. (27) Singh. 1. J. et al. In ”Proceedings of a Nuclear chemistry and Radiochemistry Symposium. 1 9 8 0 ; India Department of Atomic Energy: Bombay, India. 1981; pp. 304-8; Chem. A b m 1982, 96, 5 9 5 9 0 ~ . (28) Baumgarten, P K. el al. Pror. Symp. Wnsre Manage. 1981, 2, 1057-68; Chem. Ahzrr 1982, 96. 762291. (29) Shuckrow. A. 1 . ; Pajak, A. P ; Oshcka, J. W. “Concentration Technologies for Harardous Aqueous Waste Treatment.” EPA60012-81-019; U S . EPA: Cincinnati. Ohio.
1251 Costs. I . R
(36) Brantncr, K. A,: Cichon. E. J. In ”lndustrial Waste Proceedings of the Thirteenth Mid-Atlmic Confercnce”; Huang, C. P. Ed.; Ann Arbor Science: Ann Arbor, Mich.. 1981: pp. 43-50. (37) Kanzler, W.; Schedler, J. Chrm. Ah.m 1982.96, 5 4 1 5 0 ~ . (38) Kulowiec, 1. J. In “Industrial Waste Procecdings of the Thirteenth Mid-Atlantic Conference”: Huang, C. P, Ed.; Ann Arbor Science: Ann Arbor, Mich., 1981; pp. 27387. (39) Lyman, W. J . ; Contor. G. I n “Treatment of Hazardous Waste. Proceedings ofthe 6th Annual Research Symposium.’’ EPA-6001980-01 I ; U.S. EPA: Cincinnati. Ohio. 1980: pp. 62-71 (40) Menwei. F. et al. Water Sci. Teechnol. 1981, /3(11-12). 517-22; Chem. A h f l 1982,96. 57227r. (41) RSR Corporation Japan; Kokai Tokkyo Koho: Japanese Patent 81,146,837, 1981; Chrm A h i f r 1982, 96, 55872~. (42) Stephenson. J . B.; Cole, E. R.; Paulson, D. L. ~r.yourc,)n.,nrer~.imi, 6 ~ 4 ) 203. 10; Chcm. Ahrrr 1982,96, 7239%. (43) Mock. K . J . U.S. Patent 4,302,317, 1981; Chrm. Ahsrr 1982.96, 6Mx)4w. (44) Malone. P; Jones. L. “Guide to the Disposal of Chemically Stabilized and Solidified Waste,” SW-872; U.S. EPA: Washington, D.c.. 19x0. (45) Wright. A. P; Caretsky, S. D. In “Hazardous Waste Management”; Peirce, J. I.: Vesilind, P A . , Eda.; Ann Arbor Scicnce: Ann Arbor. Mich., 1981; pp. 71-86. (46) Thompson. D. W.; Malone, P G.: Jones, L. W. In “Toxic and Hazardous Waste Disposal”: Pojasek, R. B.. Ed.; Ann Arbor Science: Ann Arbor, Mich.. 1979: Vol. I , pp. 9-22. (47) Thompson, D. W.; Malone. P G . I n “Toxic and Hazardous Waste Disposal”; Pojasek. R. B., Ed.; Ann Arbor Science: Ann Arbor. Mich.. 1979; Vol. 2 . pp. 35-50. (48) Lubowitz. H. R. et al. I n “Treatment of Hazardous Waste. Proceedings of the 6th Annual Research Symposium,” EPA-6031980-011: U.S.EPA: Cincinnati, Ohio, 1980; pp. 43-49.
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(30) Lyubman, N. Ya.; Imangazieva, G . 73vefn. Mer. 1981. 9 . 29-31; Chem. Absfr 1982.96.74082g. (31) Huang. C. P ; Wirth. P K. I n “Industrial Waste Proceedings of the Thirteenth MidEd.; Atlantic Conference”: Conference”; Huane. Huang, C. P. Ed.: xrbor, Mich., Mich.; Ann Arbor Science: ‘Ann Ann Arbor,
Samuel I( 7ircker (I.) hos hcen employed by the Norional lnsrirure for Occuparional Safety and Healrh as a rerearch chemist since 1975. He received his B. S. in chemisfryfrom Virginia Polyrechnic Insfirure, his M.S. in chemisrry from Soufhern Illinois 1(1,?1- ~ ”... *P,.O*. .,_.., University in Carbondule, and his Ph. D. in (32) Prati Gaglia. P; Genon, G. OherJloeche surf 1981. 22112). 390-94:. Chrm. A ~ W chemistry from !he University of Norfh Carolina uf Chapel Hill. 198’~,96.74103q. Y l
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(33) Reitcrer, H. D. European Patcnt Application EP.34.137. 1981: Chem. Ahsr,: 1982, 96. 7 2 4 2 4 ~ . 134) Kocherein. V. P etal. C h m Ahrrr 1982. 96, 57529; (35) Bowers, A. R.; Chin, G . ; Huang, C. P In “Industrial Waste Proceedings of the Thirteenth Mid-Atlantic Confcrence”: Huang, Huane. Arbor Science: Ann Arbor, Arb& C. P, Ed.; Ann Aibor Mich., 1981; pp. 51-62.
George A. Carson ( r ) is an indusfrial hygiene engineer for NIOSH, Region Vll, Kansas City. Mo. He holds u B.S. und un M.S. in engineering from Kansas Sfare University as well as an M . fl H. and Ph. D. from fhe Universiry of Minnesoru. He hus served in fhe U.S.Public Health Service for 22 years.
