Abstract
This paper presents applicability of Fenton treatment to highly tetrachloroethylene (PCE)-contaminated groundwater. We performed flask-scale experiment in order to elucidate reaction mechanism in Fenton treatment of PCE in aqueous phase. Fenton treatment of PCE resulted in more than 95% of dechlorination and mineralization within 24 hours. It was found that the decomposition of PCE by Fenton treatment followed pseudo first order and its reaction coefficient was 0.17 h-1. During 24 hours in the reaction experiment the concentration of chloride ion, total inorganic carbon, and PCE in the vials were determined. These results showed that more than 98% of PCE decomposed by Fenton treatment were compensated for the increase in chloride ion and CO2 through the experiment and mineralization rates derived from the increase of CO2 are almost same to dechlorination rates from the increase of chloride ion. Detected trichloroacetic acid from GC-MS and GC-ECD analysis explained only 1% of decomposed PCE in the reaction experiment. This study suggested that both processes of dechlorination and mineralization proceeded almost simultaneously in the PCE decomposition by Fenton treatment, not via intermediates such as acetic acid and dichloroacetic acid.
