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CHEMICAL CHARACTERIZATION OF GAMMA RAY INDUCED PRODUCTS OF POLYCHLORINATED BIPHENYLS (PCB)

A number of techniques for destruction of PCBs in dielectric fluids have been developed. The PCB degradation in soil, however, is considerably more problematic. Scientists at the University of Missouri are exploring a new approach, involving irradiation of contaminated soil with 1.25 MeV gamma rays from a 60Co source either in the original soil or in soils containing an alcohol/alkane mixture.

Chemical analyses of the irradiated soils show that the PCBs are readily transformed by exposure to gamma rays. Preliminary results show that the transformation in soils occurs preferentially through reductive dechlorination. This is in agreement with results obtained by Mincher et al. Furthermore, dechlorination occurs without a preference for the position or the number of chlorines. Degradation of Aroclor 1260 from 360 ppm to Key words: polychlorinated biphenyls, irradiated soils, gamma rays, dechlorination