Electrochemical Degradation of Trichloroethylene

Trichloroethylene (TCE), a widespread and persistent environmental contaminant, is a regulated material in groundwater and soil. In this study, the electrochemical degradation of TCE was carried out using Pt/Ti-Ni as an anode-cathode material at a 0.1 A direct current. More than 99% TCE was degraded in a 69-hr reaction. The TCE degradation intermediates were identified as trichloroacetaldehyde, trichloroacetic acid, dichloroacetic acid, monochloroacetic acid, chloroform, and dichloromethane. From the chlorine balance during TCE electrochemical degradation, 98% TCE was converted to chlorine ions, chlorate ions, trichloroacetaldehyde, chloroform, and dichloroacetic acid. The degradation of the TCE intermediates was carried out to determine the electrochemical degradation pathways of TCE. The TCE degradation pathways are proposed to proceed as follows: as the main pathway, (i) TCE → trichloroacetaldehyde → trichloroacetic acid → dichloroacetic acid → monochloroacetic acid → low-molecular-weight materials; and as the subpathway, (ii) TCE → trichloroacetaldehyde → chloroform → dichloromethane → low-molecular-weight materials.