The dechlorination and degradation of Aroclor 1242

Titanocene dichloride, in conjunction with sodium borohydride and pyridine, was shown to dechlorinate Aroclor 1242 to give biphenyl. This was observed as a shift in the congener profile from more heavily chlorinated congeners to the lower chlorinated congeners over the time course of the reaction. The dechlorination process resulted in a transient increase in concentration of the monochlorinated biphenyls, particularly 3-chlorobiphenyl. Dechlorination in the presence of alternative amines or in PCB-contaminated soils proceeded at reduced rates and yielded mono- and dichlorobiphenyls in the final product. Since three hybrid bacteria had previously been produced for the mineralisation of biphenyl and lower chlorinated biphenyls, chemical dechlorination of the PCB mixture (Aroclor 1242) or of contaminated soils produces a potential feed for an aerobic microbial process for complete chlorobiphenyl mineralisation.