Keywords: 
• Pd/Fe bimetal /
• tetrachloroethene (PCE) /
• dechlorination /
• reaction kinetic

Abstract: In this study, Pd/Fe bimetal was utilized for the catalytic dechlorination of tetrachloroethene (PCE) in aqueous solution using GC-MS as the analytical method. Reaction factors such as the initial concentrations of PCE, palladium contents of the bimetal, Pd/Fe dosages and the initial pH were examined for their influences on the dechlorination. The reduction kinetics was characterized along with these reaction factors. The results showed that the efficiency of reductive dechlorination of PCE was very good with the Pd/Fe bimetal, and the reaction followed pseudofirst order kinetics. The observed kinetic coefficient K ranged from 0.019 min-1 to 0.16 min-1 with respect to the PCE concentrations, and the halflives of PCE ranged from 6 to 36 minutes, indicating the possibility of reactions occurred on the surfaces of excessive amounts of Pd/Fe bimetals. At an initial PCE concentration of 1 mmol/L , and with 1.2 g of Pd/Fe bimetal containing 0.03% Pd, the rate of dechlorination reached more than 95% after 60 minutes of reaction at 25℃. An increase in the Pd contents of the bimetal or in the dosage of Pd/Fe bimetals was effective in promoting the rates of dechlorination, and initial pH of modest acidity also favored the reductive dechlorination.