Research On Household Waster Water Treatment With Hybrid Membrane Bioreactor

A hybrid membrane bioreactor (HMBR) was devised for a pilot study for house-hold wastewater treatment.The HMBR combines both suspended growth-activated sludge and attached growth-biofilm in one bioreactor by adding suspended carriers into the mixed suspension. A UF membrane module was equipped in the bioreactor for solid/liquid separation.The comparison of treated effects between hybrid menbrane bioreactor (HMBR) and submerged membrane bioreactor (SMBR) was analyzed. The properties of the HMBR process for house-hold wasterwater treatment and reuse was studied.In addition, the microorganism characteristics and these simultaneous nitrification and denitrification were studied. The controlling parameters on membrane fouling were detected experimentally. Finally, the treated effects of HMBR in low temperature were studied. The main results of this study are as follows:1. The efficiencies of HMBR and SMBR for wastewater treatment were compared at parallel operational conditions. The experimental results showed that the turbidity, COD_Cr, TOC, NH3-N and TN effluent in HMBR system were lower than that in SMBR system. The attached growth-biofilm in HMBR system can improve the disadvantages caused by sludge expansion and poor settlement, with the result of good operational stability in HBR process. The HMBR process has a good out water .The COD_Cr was always about 10 mg/L, the NH3-N was always lower than 2 mg/L, the average removal was 95%,and the TN average as 15.3mg/L,the removal was 62%.2. When the range of DO in 1.3³.2mg/L or1.5².2mg/L,the removal of COD_Cr and NH3-N is best. When the pH only higher a litter than 7, the effect will better; when HRT=8h, the removal will be high.3. The HMBR has also high effect for its ability of effective nitrification/denitrification removal.The extaordinary chansmit way of attached growth-biofilm is the key factor.4. The operational conditions on the membrane fouling were experimented .The HMBR system was operated intermittently with the the proper suction time was 6 min, halt time was 5 min, aeration intensity was 12 m³Â·m^-2·h^-1,the concentration of Suspended Sludge was 2 g/L and the attach was 6 g/L, membrane flux was 20L/(m²Â·h). And net aeration, water backwash and chemical washing take the TMP lower effectily.5. In the 10¹5℃low temperature condition,the HMBR has many kinds of actively microrganisms in sludge, so the COD_Cr and NH3-N in the out water is very low. The MF membrane plays a main role.