Alleviating the release of dissolved chlorobenzene by microbial electrochemical system to improve the performance of...

The insufficient microbial degradation capacity of dissolved chlorobenzene in the reflux liquid restricts the further performance improvement of the biotrickling filter (BTF) for purifying organic exhaust. Here, electrical stimulation is used to stimulate the removal of dissolved chlorobenzene in reflux liquid in the combined system of microbial electrochemical system and BTF (MES-BTF), aiming to improve the degradation efficiency of chlorobenzene. The concentration of dissolved chlorobenzene in the reflux liquid decreases from 0.27 mg/L to 0.21 mg/L for 200 ppm chlorobenzene with the applied 1.6 V voltage. The integrated system achieves a maximum chlorobenzene removal efficiency (RE) of 68.71 % and a mineralization rate of 19.64 g/m³/h, representing an improvement of approximately 11.7 % over the control. Electrical stimulation provides an additional bioelectrochemical degradation pathway of chlorobenzene with the 3-chlorocatechol, 4-hydroxy-2-oxovalerate, and chlorohydroxybenzene as the intermediates. Bioanalysis in spatial distribution reveals the polysaccharides and Pseudomonadota spp. are crucial for the removal of chlorobenzene in the combined system. This study demonstrates an effective strategy to enhance the degradation of dissolved chlorobenzene and provides new insights for optimizing biotechnology for exhaust purification.