Electrolytic oxidation of trichloroethylene using a ceramic anode

Trichloroethylene (TCE) was transformed to CO2, CO, Cl- and ClO3- at the anode of a two-chambered electrolytic cell. The working electrode was constructed from Ebonex(R), an electrically conductive ceramic (Ti4O7). Under our experimental conditions (anode potential E-a = 2.5 to 4.3 V vs SSCE), the disappearance of TCE was first order in TCE concentration. The transformation rate was independent of pH in the range 1.6 < pH < 11. TCE oxidation occurred only on the anodic surface and was limited by mass transport at high potentials (E-a > 4.0V). The maximum (transport-limited), surface-area-normalized rate constant was about 0.002 43 cm s(-1). Carbon-containing products included CO2 primarily with traces of CO. At neutral and alkaline pHs, the only chlorine-containing products were Cl- and ClO3-. Hydroxyl radicals were detected in the anodic compartment using a spin trap (4-POBN). A kinetic model was successfully correlated with experimental results.