Radiolytic dechlorination of polychlorinated biphenyls in transformer oil and in marine sediment

Radiolytic dechlorination. of polychlorinated biphenyls (PCBs) in transformer oil and in marine sediments has been studied. At low PCB concentrations, complete degradation of the PCBs in transformer oil was achieved without degradation of the oil. Addition of an organic base, triethylamine, enhances the radiolytic dechlorination yield. The mechanism of dechlorination has been shown to involve electron transfer to PCBs from various aromatic radical anions formed in the irradiated oil. At high PCB concentrations, large amounts of triethylamine were necessary to achieve complete radiolytic dechlorination. Preliminary results on PCB-contaminated marine sediments demonstrate that addition of 2-propanol to the sediment/water slurry increases the effectiveness of the electron beam treatment. (C) 2002 Elsevier Science Ltd. All rights reserved.