Catalytic dechlorination of polychlorinated biphenyls in soil by palladium-iron bimetallic catalyst.

Pd/Fe bimetallic particles were synthesized by chemical deposition and used to dechlorinate 2,2',4,5,5'-pentachlorobiphenyl in soil. Batch experiments demonstrated that the Pd/Fe bimetallic particles could effectively dechlorinate 2,2',4,5,5'-pentachlorobiphenyl. Dechlorination was affected by several factors such as reaction time, Pd loading, the amount of Pd/Fe used, initial soil pH, and 2,2',4,5,5'-pentachlorobiphenyl concentration. The results showed that higher Pd loading, higher dosage of Pd/Fe, lower initial concentration of 2,2',4,5,5'-pentachlorobiphenyl and slightly acid condition were beneficial to the catalytic dechlorination of 2,2',4,5,5'-pentachlorobiphenyl. The degradation of 2,2',4,5,5'-pentachlorobiphenyl, catalyzed by Pd/Fe followed pseudo-first-order kinetics.