Reductive Dehalogenation of Aqueous-Phase Chlorinated Hydrocarbons in an Electrochemical Reactor

Abstract

This work describes the reductive dehalogenation of carbon tetrachloride (CT) in a novel liquid-phase electrochemical reactor. The reactor consists of a cylindrical porous copper cathode with a concentric carbon-cloth anode wrapped around the cathode. The results show that CT destruction can be achieved, even in low conductivity solutions (i.e., deionized water), reaching 80% conversion of CT with a residence time of 10 min when a cathode potential of −0.4 V (versus a standard hydrogen electrode) is used. A mathematical model was formulated to simulate reactor performance. The model accounted for CT reductive dechlorination, hydrogen evolution on the cathode surface, and CT mass-transfer limitations. The equilibrium potential for CT reduction on the cathode surface was the only adjustable parameter. The model adequately represented experimental data under high-conductivity (2.2 S/m) and low-conductivity (0.05 S/m) conditions. The model results and experimental observations suggest that the entire cathode ...