Treatment of TCE- and PCE-contaminated groundwater using UV/H₂O₂ andO₃/H₂O₂ oxidation processes

The feasibility of O₃/H₂O₂ and UV/H₂O₂ treatments the purification of groundwater contaminated with trichloroethylene (TCE) and tetrachloroethylene (PCE) was evaluated by laboratory and pilot-scale studies. Both methods showed rapid and extensive removal of the chlorinated ethylenes. Chloride measurements and by-product studies indicated a high level of mineralization. The health-based guidelines set by the World Health Organization were easily achieved for PCE and TCE as well as the predicted-no-effect-concentration (PNEC) values reached with extended treatment time. Owing to the partial stripping of TCE and PCE during ozonation treatment, UV/H₂O₂ was selected for further studies in a continuous-flow mode using a commercially available UV-sterilizor. The continuous-flow studies suggest UV/H₂O₂ could be useful for the purification of contaminated sites.