EVALUATION OF BIOREMEDIATION BY INTRODUCING DEHALOCOCCOIDES MCCARTYI STRAIN UCH007 INTO AN AQUIFER SIMULATING CONTAMINATION BY CHLORINATED ETHYLENES

Abstract

 The effect of introducing the Dehalococcoides mccartyi strain UCH007, which completely dechlorinates chlorinated ethylenes, on bioremediation of trichlorethylene was evaluated in the batch culture experiment simulating aquifer contamination caused by convection-diffusion of pollutant from groundwater. The culture bottles were amended with sodium lactate in soil pore water and were cultured at 20℃ for 3 weeks. After confirming that the bottles were reached to an anaerobic sulfate-reducing condition, UCH007 was inoculated into the bottles. The groundwater concentration and soil elution amount of all chlorinated ethylenes including intermediates decreased below regulatory standards at 3 weeks after the inoculation of UCH007. UCH007 was present in the culture bottles at 0.1% proportion of total bacteria at the time of inoculation, but its number was maintained until the end of the remediation. It was shown that even a small number of UCH007 contributes to the rapid dechlorination of chlorinated ethylenes to harmless ethylene.