Electro-coagulation process has been gained an attention recently because it could overcome the membrane fouling problems in MBR (membrane bio-reactor). Effect of the key operational parameters in electro-coagulation, current density (ρi) and contact time (t) on membrane fouling reduction was investigated in this study. A kinetic model for ρi and t required to reduce the membrane fouling was suggested under different MLSS concentration. Total 48 batch type experiments of electro-coagulations under different sets of current densities (2.5, 6, 12 and 24 A/m2), contact times (0, 2, 6 and 12 hr) and MLSS (mixed liquor suspended solids) concentration (4500, 6500 and 8500mg/L) were carried out respectively. After each electro-coagulation under different conditions, a series of membrane filtration was performed to get information on how much of membrane fouling was reduced. The membrane fouling decreased as the ρi and t ... but as MLSS ...

Total fouling resistances, Rt (=Rc+Rf) were calculated and compared to those of the controls (Ro), which were obtained from the experiments without electro-coagulation. A kinetic approach for the fouling reduction (Rt/Ro) rate was carried out and three equations under different MLSS concentration were suggested: ρi^n*t = constant. Those equations state that the product of ρi and t needed to reduce the fouling in certain amounts (in this study, 10% of fouling reduction) is always ...