DECHLORINATION OF POLYCHLORINATED-BIPHENYLS ON SOILS AND CLAY BY ELECTROLYSIS IN A BICONTINUOUS MICROEMULSION

Electrochemical catalytic dechlorination using a bicontinuous microemulsion was investigated as a method for the decontamination of characterized soils and clay contaminated with 4,4'-dichlorobiphenyl and Aroclors. Using a lead cathode and a microemulsion of didodecyldimethylammonium bromide, dodecane, and water, dechlorination to biphenyl was achieved in all contaminated particulate samples examined. Dechlorination rates and current efficiencies for 4,4'-dichlorobiphenyl decreased as the organic content of the soils increased from 0.36 to 6.6%. In soils with 6.6% organic matter contaminated with 14% Aroclor 1260 (84 mg of PCBs), 94% dechlorination was achieved with a current efficiency of 50% during a 12-h catalytic electrolysis in 20 mt of microemulsion. Results suggest that electrolyses in microemulsions may be useful for the cleanup of soils and sediments contaminated with PCBs.