Dechlorination of 4-chlorophenol to phenol in bioelectrochemical systems.

Bioelectrochemical systems (BESs), such as microbial fuel cells (MFCs) and microbial electrolysis cells (MECs), are generally regarded as a promising key technology to effectively treat wastewater and better exploit the renewable resource. This study explored the use of a BES to abiotically cathodic dechlorination of aromatic chlorides such as 4-chlorophenol, where the process was driven by microbial oxidation of glucose at the anode. It was confirmed that the 4-CP reduction process was feasible in BES and the dechlorination efficiency of 4-CP could achieve 50.3% at the cathode with energy generation. The 4-CP dechlorination efficiency was significantly enhanced when the BES was supplied with voltages, reaching up to 92.5% at an energy consumption of 0.549 kWh mol(-1) 4-CP (at applied voltage of 0.7 V). Besides, phenol was identified as the major product of 4-CP dechlorination at the cathode of BES in this study, which was the same as electrochemical reduction.