The Study On Domestic Wastewater Treatment By Membrane Bioreactor (MBR)

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 rapid 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 made up of the activated sludge bioreactor and membrane treated the domestic wastewater in the experiment. The test researched the treatment performance of municipal sewage with the submerged membrane bioreactor. When the concentration of sludge was 5500mg/L, the concentration of DO was 3mg/L, HRT was 4hours, the time of pump was15min and the time of stop was 5minin the experiment, the results indicated that the removal rates of BOD₅ were about 95.8%, the effluent levels of BOD₅ were under 7mg/L; the removal rates of COD were about 90%, the effluent levels of COD were under 50mg/L; the NH₃-N removal efficiency was up 93%, the effluent levels of NH₃-N was about 0.48-3.88mg/L. In a word, membrane bioreactor combination technology has advantage over the other existed technologies in reducing many pollutants of wasted water after treatment.Due to less sludge discharge and longer cell detention time, the biological removal phosphorus efficiency of the submerged membrane bioreactor was not well. The effluent levels of phosphorus were between 2.08-5.82mg/L, the removal rate was about 22.8-53.7%.The mechanism of membrane fouling was discussed. Membrane technology has the characteristics of concentration polarization and surface pollution: it has limitation to apply the membrane technology for water recycle. In this paper, the experiment result showed that intermittent pump drainage and aeration could reduce the concentration Polarization and the fouling of membrane module.The leaning effect of the different chemical medicine was validated. To the different raw water, different chemical medicine and treatment should be used.