Anaerobic co-metabolic biodegradation of tetrabromobisphenol A using a bioelectrochemical system

[Display omitted] •Anaerobic co-metabolism of TBBPA was studied in a bioelectrochemical system.•Two different biodegradation pathways were suggested.•Microbial diversity analysis of biofilm was carried out.•Azoarcus was speculated as the major microorganism for the biodegradation of TBBPA. Tetrabromobisphenol A(TBBPA), a pollutant in industrial wastewaters, needs to be removed due to its high toxicity and persistence. The main biodegradation pathway for TBBPA has been studied, and bisphenol A(BPA), which is toxic to the environment, is recognized as the general terminal product. In this study, we explored a new approach for the anaerobic biodegradation of TBBPA in a bioelectrochemical system (BES) through co-metabolic degradation of TBBPA with glucose. The half-life of TBBPA was significantly reduced to 13.5h−1 at 25μg/l of TBBPA. With an increase in the concentration of TBBPA, the removal rates of TBBPA rose to more than eighty percent. Based on the analysis of the products, we found that the degradation products of TBBPA were 2,6-dibromo-4-(1-methyl-1-phenylethyl) phenol, (double-benzenes product) and 2,6-dibromo-4-(prop-1-en-2-yl) phenol (single-benzene product), rather than BPA. Simultaneously, we proposed two degradation pathways for TBBPA in a BES system. According to the microbial diversity analysis of the anode biofilm, we speculated that the microorganism responsible for the biodegradation of TBBPA was Azoarcus. Additionally, we briefly analyzed the effect of TBBPA on the performance of BES system to pave the way for the further analysis of the interaction between the TBBPA and the BES system.