Membrane Bioreactor for Treatment of Micro-polluted River Water

The treatment of micro-polluted river water by membrane bioreactor(MBR) combined with powdered activated carbon(PAC)adsorption was studied.The pollutant removal performance was compared with that of the ultrafiltration(UF) process.The pore size and area of polyethylene hollow fiber ultrafiltration membrane were 0.2 μm and 2 m2 respectively.The activated carbon and sludge concentrations of MBR/PAC process were 0.5 and 2 g/L respectively.Time controller was used to operate the water pump intermittently,and the open/stop time ratio was 8 min/2 min.The results show that the removal efficiencies of CODMn,TOC,UV254 and UV410 are much higher in MBR/PAC than those in UF.In the MBR/PAC process,85% to 100% of UV410 and more than 50% of CODMn,TOC and UV254 can be removed.CODMn concentration in the effluent meets the national drinking water standard.The removal rates of ammonia nitrogen,Fe and turbidity are above 80%,87% and 90% respectively,and their effluent concentrations are below 0.5 mg/L,0.1 mg/L and 0.5 NTU respectively,satisfying the Standards for Drinking Water Quality(GB 5749-2006).