Improved dechlorination and mineralization of 4-chlorophenol in a sequential biocathode–bioanode bioelectrochemical system with mixed photosynthetic bacteria

A new approach that improved the dechlorination and mineralization of 4-chlorophenol (4-CP) was demonstrated in a sequential biocathode–bioanode bioelectrochemical system (BES) with mixed photosynthetic bacteria (PSB). The biocathode with additional PSB inoculation showed higher 4-CP dechlorination efficiency (DE) and maximum current (81.8   ±   2.9%, 0.021   ±   0.002   A) than that at abiotic cathode (45.3   ±   3.7%, 0.011   ±   0.002   A) ( P   <   0.005). Light response in biocathode BES with or without PSB ascertained the important role of PSB played in the dechlorination and current generation. Dechlorination and mineralization of 4-CP was achieved in the sequential biocathode–bioanode BES, which could be further enhanced with PSB inoculation in both cathode chamber and anode chamber. 4-CP DE in the cathode chamber was improved from 55.0   ±   2.0% to 78.8   ±   4.9%, and the phenol degradation in the anode chamber was improved from 65.3   ±   2.1% to 71.3   ±   1.4%. This study directed a new way for improving dechlorination at biocathode and product degradation at bioanode with PSB inoculation in BES.