Impacts of energy distribution and electric field on membrane fouling control in microbial fuel cell-membrane bioreactor (MFC-MBR) coupling system

To investigate the influence of energy allocation on membrane fouling, three coupling systems at different concentrations of mixed liquid suspended solids (MLSS) and a control system without microbial fuel cell (MFC) were established. The results show that MFC acted negative effect in low-loading stage (0.59 kg-COD.m(-3).d(-1)), while high MLSS acted active effect on organics degradation in high-loading stage (2.00 kg-COD.m(-3).d(-1)), and electric field could be a positive factor with sufficient energy. Besides, membrane filtration experiments in the electric field with microbial contaminants indicate that soluble microbial products (SMP) and loosely bound extracellular polymeric substances (LB-EPS) had greater tendencies to cause irreversible membrane fouling. SMP and the residual cell liquid (Cell) were more susceptible than extracellular polymeric substances (EPS), demonstrating that the irreversible fouling was reduced mainly due to SMP decrease in the electric field.