Highly effective degradation of polychlorinated biphenyls in soil mediated by a Ca/Rh bicatalytic system

Treatment of PCBs in soil using metallic calcium and alcohol ultimately reduced 1300 × 10−3 mg kg−1 PCB concentration to 1.8 × 10−3 mg kg−1. Moreover, using the metallic calcium catalyst method to promote the effective use of hydrogen gas in the presence of a specific reducing catalyst such as Rh/C, the decomposition efficiency of PCBs was notably increased despite mild reaction conditions. The total PCB concentration of treated soils decreased from 1300 × 10−3 mg kg−1 to 0.62 × 10−3 mg kg−1 (decomp. avg. = 99.95%). Treatment of soils with metallic calcium and a Rh/C catalyst in alcohol under mild conditions such as 0.15–0.26 MPa at room temperature is extremely effective for degradation of existing PCBs.