Highly Efficient Transformation of Bisphenol S by Anaerobic Cometabolism in the Bioelectrochemical System

Bisphenol S (BPS) is considered to be a persistent pollutant in the environment. In this study, an anaerobic bioelectrochemical system (BES) is established for BPS biotransformation with the goal of discovering a new pathway for BPS transformation and improving the removal efficiency of BPS. The results of the study suggest that the BES exhibits high-level BPS biotransformation that is better than that of conventional anaerobic cometabolism. The removal efficiency of BPS was as high as 92.9% at 0.1 mg/L BPS. The intermediate products were analyzed comprehensively, and 4,4′-thiodiphenol, 1,2,3,4-tetrahydrodibenzo[b,d]thiophene, methyl(o-tolyl)sulfane, and phenol were found to be major products of BPS transformation, which indicated new pathways of biotransformation. In addition, the microbial diversity on the electrode biofilm was also identified. Rhodococcus and Chelatococcus are the major bacteria in BES, which further proves the new transformation process of BPS using BES. Therefore, the results of this study have great significance for improving BPS transformation in the environment.