Reductive dechlorination of hexachlorobenzene under various additions

Microorganisms collected from sediments of Ho-Tsin River in southern Taiwan were used in this study. The ability to dechlorinate hexachlorobenzene (HCB) was induced by enrichmentincubation in yeast extract amended culture and acclimation withHCB. Addition of lactate or replacement of yeast extract by lactate did not enhance the dechlorination ability. With strong electron capturing capability, denitrifying bacteria resulted incomplete inhibition of dechlorination in the mixed culturecontained nitrate. In the culture amended with sulfate, sulfate reducing bateria shared electrons and nutrient with HCB-dechlorinating consortium but grabbed more electrons when treated with vancomycin. Results from multi-factors tests indicate that the influences of factors on dechlorination werecomplicated. Dechlorinating microbes, electron suppliers, sulfatereducing bacteria and denitrifying bacteria, all possibly caused a great effect on dechlorination.[PUBLICATION ABSTRACT]