Methods to deactivate hazardous chemical wastes are reviewed. Hazardous chemical wastes may be toxic, reactive, corrosive, radioactive, carcinogenic, mutagenic, or teratogenic. Deactivation by chemical conversion, removal of hazardous constituents, and stabilization are examined. 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. Chemical conversion processes and the types of waste to which they are applicable include: wet oxidation for a variety of organic compounds; ozonation used for phenols, cyanides, and organic lead (7439921) compounds in wastewaters; molten salt combustion applicable to a variety of organic compounds; electrochemical oxidation for cyanate (661201), thiocyanate (302045), acetate (71501), phenols, and cresols; treatment with formaldehyde (50000) for chromium(VI) (18540299), cyanide ion (57125), and metal/cyanide complexes; catalytic reduction with metal powder employed with chlorinated organic compounds in wastewaters; catalytic hydrogenation for polychlorinated hydrocarbons; dechlorination for polychlorinated organic compounds; destruction by microwave plasma for pesticides and polychlorinated biphenyls; hydrolysis for organophosphorus and carbamate (302114) pesticides; and neutralization for strong acids and alkalis. Each process is described and discussed. Processes for the removal of hazardous constituents which are examined include: adsorption on carbon, ion exchange, cementation, precipitation, liquid/liquid extraction, ultrafiltration; reverse osmosis; and electrolytic reduction. Stabilization is also discussed. This 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. Solidification with cement, thermoplastic materials, or organic polymers is described. Encapsulation, solidification by self cementation or lime based processes, and vitrification are also examined. The authors conclude that deactivation lowers worker exposure, decreases storage needs, lowers handling and transportation costs, and has a smaller impact on the environment.
DCN-138296; Biological effects; Toxicology; Environmental health monitoring; Toxic materials; Genetic factors; Industrial hazards; Chemical analysis; Industrial equipment; Trace analysis; Exposure levels; Environmental hazards; 7439-92-1; 661-20-1; 302-04-5; 71-50-1; 50-00-0; 18540-29-9; 57-12-5; 302-11-4