Electrochemical reduction of haloacetic acids and exploration of their removal by electrochemical treatment

The electrochemical reduction of chlorine- and bromine-containing haloacetic acids (HAAs) was quantified using copper and gold electrodes. All HAAs (except monochloroacetate) were shown to be electrochemically active. The rate of reduction increased with the number of halogen atoms in the organic molecule and was higher for copper. It was determined that the electrochemical treatment could lead to a virtually complete dehalogenation of brominated HAAs. However, the electrochemical treatment of chlorinated acetic acids was accompanied by the formation of monochloroacetate, whose direct reduction is difficult. Although the yield of the latter species decreases at increasingly cathodic potentials, the formation of monochloroacetic acid is likely to constitute a limitation for the total dehalogenation of chlorinated HAAs. (C) 2001 Elsevier Science Ltd. All rights reserved.