Simulation of the Reductive Dechlorination Processes in a Lab-Scale Anaerobic Biobarrier with the Enriched TCP Dechlorination Consortium

摘要

In order to facilitate the design and predict the dechlorination processes for remediating the halogenated aromatic compounds in the biobarrier system applied in situ, an anaerobic continuous flowing column was set up with the introduction of an enriched TCP dechlorinating consortium. The fates of TCP and its metabolites were simulated according to the first-order sequential dechlorination kinetic model. The enriched TCP anaerobic dechlorinating consortium dechlorinated 2,4,6-TCP of 100 μM to 4chlorophenol (4-CP) via 2,4-dichlorophenol (DCP) in 10 days. The consortium was predominated with phylum of Firmicutes and Bacteroidetes, based on the PCR- denaturing gradient gel electrophoresis (DGGE) analysis. After the consortium applied into the column, the experimental data at the steady state were fitted with the least square method and the first-order dechlorination kinetic constants from TCP to DCP, from DCP to 4-CP and from 4CP to phenol, were 1.58 day'1, 2.23 day"1 and 0.206 day-1, respectively. According to the fitting results, the required biobarrier width for the complete remediation of TCP, DCP and 4CP were 126 cm, 130 cm and 689 cm, respectively. The dechlorination/ degradation of 4-CP must be increased when the technology is applied to the real site.