A COMBINED METHOD FOR COMPLETE DEGRADATION OF PCBS: COMBINATION OF ULTRAVIOLET AND BIOLOGICAL TREATMENTS

Some chlorinated substrates are dechlorinated photochemically by ultraviolet (UV) irradiation. To evaluate the dechlorination ability of UV light for polychlorinated biphenyls, methanol solutions of Kaneclor 500, which mainly consists of penta-chlorinated biphenyls, were put into a screw-capped quartz glass cell and irradiated at room temperature for 26 hours. Most of the congeners were transformed into low chlorinated congeners that had less than three chlorine. Congeners that remained after UV irradiation did not have any chlorine at ortho position. Further irradiation was not useful for dechlorination and UV irradiation was replaced with biological treatment.