Evaluation of alternative processes for final treatment of hazardous waste effluents

Five process unit operations were evaluated for effectiveness in treating aqueous effluent from a hazardous waste treatment facility. The aqueous effluent contained residual amounts of various organics and heavy metals. The objective of the pilot test program was to produce an aqueous product which could meet requirements for discharge to a POTW, or directly to the environment, and a solid product which could be disposed of in a Class I landfill. Processes evaluated included one primary, evaporative crystallization, two secondary, activated sludge bio‐treatment and reverse osmosis, and two tertiary, carbon adsorption and ultraviolet peroxidation. Test results from these process operations identified several processing configurations whereby the final treated product could meet discharge criteria. Performance results of each process unit operation are summarized and discussed.