Performance and membrane fouling characteristics in a membrane bioreactor coupled with microbial fuel cell system

Membrane bioreactor (MBR) is an effective process for wastewater treatment, and the microbial fuel cell (MFC) can use nitrate as electron acceptor to remove nitrogen. In this study, a MBR coupled with MFC (MFC-MBR) was established to simultaneously remove nitrogen and mitigate membrane fouling. The performances of wastewater treatment systems, the membrane fouling and the characteristics of mixedliquor were investigated in both the control-MBR, and MFC-MBR. The results showed that the two systems had the similar removal efficiencies of COD (88%) and NH₄-N (99%). The total nitrogen removal efficiency in the MFC-MBR (69.4%) was higher in comparison with that in the control-MBR (55.3%). The ratios of mixed liquor volatile suspended solids (MLVSS) to mixed liquor suspended solids (MLSS) for the two systems were almost identical, and both maintained at 88%. The MFC-MBR system could modify thecharacteristic of mixed liquor, leading to a lower viscosity, higher zeta potential and larger size of microbial flocs. Moreover, the chemical cleaning cycle period was prolonged by 41.17%.