INFLUENCES OF SHORT CHAIN CARBON SUBSTRATES OR FERROUS IRON ON ANAEROBIC REDUCTIVE DECHLORINATION OF HEXACHLOROBENZENE IN THE LIAO RIVER SEDIMENT

摘要

The anaerobic dechlorination of HCB (hexachorobenzene) in the Liao river sediment under seven conditions were investigated, which were followed pseudo-first-order kinetics; however, the extents and rates of dechlorination were different, even the original concentration of HCB were the same. With the existence of sodium lactate or sodium propionate, and inoculated by the No.l culture, the anaerobic dechlorination rate was improved from 0.0055 d~(-1), which was the dechlorination rate of HCB when no additional carbon source existed, to 0.0067 d~(-1) and 0.0058 d~(-1), respectively. While inoculated by the No. 2 culture, the anaerobic dechlorination rate of HCB was improved to 0.0078 d~(-1). When only FeSO_4 existed, it restrained the degradation of HCB with the No. 2 inoculant. While both sodium acetate and FeSO_4 were present, the anaerobic dechlorination rate of HCB was improved to 0.0086 d~(-1), which was the same as the rate when only sodium acetate existed. It means that the repressive effect of SO_4~(2-) can be removed by the addition of sodium acetate, but the reductive dechlorination of HCB in anaerobic sediment was very difficult, even the electron was enough.