| Membrane bioreactor(MBR) was a reasonable combination of biological treatment technology and membrane technology with many advantages such as high removal efficiency of pollutants,little surplus sludge,stable and high quality of effluent,so it was becoming a new and raqid developing wastewater treatment and reclamation technology,so the research on the basic theory and the performance of MBR would benefit to the application and spread of this process.The integrative membrane bioreactor that was maked up of the activated sludge bioreactor and membrane treated the domestic wastewater in the experiment.When the concentration of sludge was 6000mg/L,the concentration of DO was beyond 3mg/L,and HRT was 6 hours in the experiment, the CODcr,BOD5,SS,NH3-N,TN,TP removal efficiencies were 95%~98%,98%~99.5%,100%,92%~100%,60%~84%and 34 %~64%,respectively.With a view to the unconspicuous TP removal efficiency by membrane bioreactor, TP was removed efficiently by chemic medicine of aluminate,and when the rate of Al and TP(mol) equal to 1.5~2.0,the TP removal efficiency was 72%~86%.With the study of temperature,pH value,HRT and Doconcentration,it was therefore found that it was not obvious to the influence of DO concentration on the CODcr,BOD5 and NH3-N removal efficiencies when the concentration of DO was beyond 1.5mg/L,and the influence was large when the concentration of DO was 0.5mg/L.When the concentration of DO was 1.5mg/L,the influence of DO concentration on the TN removal efficiency was 92%~98%,otherwise the TN removal efficiency decline. The influence of HRT on the system removal efficiency was that microbe haven't the sufficient reactiving time with wastewater which was expelled from the system,and it wasn't obvious when HRT was enough. Along with increasing of HRT,the influence of HRT on TP removal efficiency enhanced firstly and then declined. It wasn't obvious to the influence of temperature and pH value on the contamination removal efficiency.When studying simultaneous nitrification and denitrification in membranebioreactor,it was foud that the concentration of DO was a key factor and the influence of C/N,pH value and temperature were unconspicuous.When C/N,pH value, temperature and DO concentration were 8~ 18,7.0~8.5,7 13 and 1.5mg/L, simultaneous nitrification and denitrification might proceed smoothly and this was the optimal condition. With analysing the mechanism of simultaneous nitrification and denitrification,it was founded that it was related with the theory of DO odds in reactor and micro-evironment,and it was effcted indirectly by the configuration of reactor and sludge concentration that simultaneous nitrification and denitrification might proceed.When studying membrane fouling,the increasing rate of suction pressure of membrane was used to evaluate the membrane filtration characteristics of membrane bioreactor process.Through a group of test by means of orthogonal table,influence of suction time,suction suspended time and aeration rate on membrane filtration was investigated. Shorter suction time,longer suction suspended time and larger aeration rate could alleviate membrane fouling.which influenced accumulation and back transportation of pollutants an and from membrane surface.The optimum operation parameters were 10 minutes of suction time,4 minutes of suction suspended tim and aeration rate of 0.05m3/h under the condition of sludge concentration 6000mg/L and flux of membrane 5L/(m2 ?h).Suction time was the key factor among these three factors,and suction suspended time had the least impact on membrane fouling.
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