| Batch incubation experiments in aid of anaerobic incubation flask were conducted to study the anaerobic degradation and volatilization of hexachlorobenzene (HCB), the change of pH in soil, the emission of CH4 and CO2, and the volatilization of HCB in the Hydragric Acrisol and Gleyi-Stagnic Anthrosol added with acetic acid, glucose and citric acid. Results showed that HCB was reduced by 20％-44％ in Hydragric Acrisol during 8 weeks, and addition of acetic acid inhibited the dechlorination, indicating that dechlorination was impeded at low pH. Addition of glucose or citric acid decreased the dechlorination rate initially and then increased it. HCB was reduced by 21％-23％ in Gleyi-Stagnic Anthrosol, and there was no obvious effect by adding low-molecular-weight organic carbon. The main product of HCB anaerobic dechlorination was pentachlorobenzene (PCB), which were 23-96 μg/kg and 64-92 μg/kg in Hydragric Acrisol and Gleyi-Stagnic Anthrosol respectively. Furthermore, the degradation of HCB had no statistically significant correlation with the productions of CH4 and CO2. Addition of low-molecular-weight organic carbon reduced HCB volatilization, which was stronger in Hydragric Acrisol than in Gleyi-Stagnic Anthrosol, indicating that soil organic matter was an important factor in HCB volatilization. |
