In this paper, wastewater was treated with Recirculated Membrane Bio-Reactor (RMBR) and effluent quality became stable after four days running continuously. Critical membrane flux was increased with increasing crossflow velocity between 0.9-1.9 m/s. Under crossflow velocity of 1.9 m/s, critical membrane flux was enhanced from 72 L/(m2.h) to 76 L/(m2.h) or 81 L/(m2.h) respectively when powdered activated carbon (PAC) or both PAC and alum were added to the system. Between 22 degrees C-30 degrees C, the flux was elevated 1.9% per 1 degree C increased. Fouling materials were removed efficiently through cleaning physically or/and chemically with flux recovery of 47%-94%.