Abstract: A pilot-scale anaerobic/anoxic/aerobic-membrane bioreactor was utilized to treat wastewater from the primary sedimentation tank in a municipal wastewater treatment plant in Beijing.After about 200 days of experimental study,it shows good removal efficiency of chemical oxygen demand (COD),biological oxygen demand (BOD),and total organic carbon (TOC),which reaches stably 92%,98%,and 85%,respectively at the hydraulic retention time(HRT) of 12.5 h.Contribution of COD removal by biodegradation and microfiltration is 89% and 11%,respectively.The removal efficiency of NH₄⁺-N,and total nitrogen (TN) is about 98%,85%,with on average ρ(TN) of permeate 10 mg/L.The removal efficiency of TP is about 85%,with ρ(TP) of permeate about 0.93 mg/L at the sludge age of 40 days.The proportions of TP removal by denitrifying phosphorus removal,the aerobic phosphorus uptake,and membrane cut-off is 44.6%,51.8%,3.6%,respectively.The permeation of extreme low turbidity and almost non-SS can be reclaimed for the urban miscellaneous water consumption.Intermittent suction,scouring aeration,on-line hydraulic backwash,and regular drug-wash as a mean of inhibiting membrane fouling,ensures the sustainable running of the whole system.