Impact of bioelectric field on biogas production, membrane fouling and microbial community in an anaerobic membrane bioreactor under sulfadiazine stress

Anaerobic membrane bioreactor (AnMBR) treatment of swine wastewater (SW) can recover energy efficiently. Still, antibiotics such as sulfadiazine (SDZ) in SW can reduce operational efficiency and cause severe membrane fouling. This study investigated the performance of an integrated microbial fuel cell MFC.AnMBR system under different SDZ concentrations, focusing on methane, membrane fouling, and microbial dynamics. Results showed that the bioelectric field in the MFC-AnMBR improved COD removal by 2.8%~7.3%, enhanced methane production by 12.5%~35.5%, and reduced Volatile Fatty Acids (VFAs) accumulation by 35.33%~56.13% than conventional AnMBR under SDZ stress. Meanwhile, the bioelectric field reduced soluble microbial products (SMP) by 6.3~43.0%, extracellular polymeric substances (EPS) by 21.9%-43.3% and the membrane fouling cycle was prolonged by more than 36 days than conventional AnMBR under SDZ stress. Microbial analysis revealed that the bioelectric field enriched methanogens by 0.5%~3.0% than conventional AnMBR under SDZ stress. Moreover, the bioelectric field optimised the bacterial community on the membrane modules, which helped mitigate membrane fouling. In conclusion, the bioelectric field enhances the overall performance of AnMBR systems under SDZ stress, improving energy recovery and membrane fouling resistance.