| Membrane bioreactor (MBR) is an innovative and high-efficient technology for Wastewater treatment, which combines UF/MF membrane technology and activated sludge process together, And MBR has been proved to have the dvantages of highly improved effluent quality, increased organic loading, reduced footprint occupation and sludge production. However, wide acceptance of the MBR system in the Wastewater treatment process has been hindered by some technical or economic problems such as membrane fouling, unreasonable operational conditions, high investment and operation expenditure. In addition, there appears to be limited studies in the literatures on influence of operational parameters.In this paper, MBR and hybrid MBR systems were applied to treat Wastewater. The mechanisms of mass transfer, mechanisms of membrane fouling, design principle for MBR system were discussed and investigated in order to develop a technologically and economically feasible MBR system. Also, long-term operational performance was monitored and studied in order to solve membrane fouling and cleaning problems, explore reasonable operational parameters, and improve capacity of membrane modules.Filtration characteristics and mechanism of membrane fouling were investigated with MBR mixed liquor. The result showed that, the variation of filtration resistance was fit to the standard blocking filtration model in initial process, and then fit to cake filtration model in later process. In dead-end filtration of sludge, the relative flux was in the tendency to the exponential decay along with filtration time, and flux was decreased more quickly at higher pressure. Sludge was compressed during filtration process, and resistance of sludge was increased with the increase in filtration pressure, the compressibility index was obtained as 0.8078. Quantitative calculations showed that cake resistance made up over 90% of total resistance. From the studies above, technical and economic analysis of this pilot MBR system was conducted. Then, a novel SMBR flat sheet membrane element (module) was developed, and this membrane module operated stably and was easy to clean. Meanwhile, bioreactor configuration, pump selection and blower design were discussed. This MBR system was then applied to treat printing and dyeing Wastewater, secondary effluent. The results showed that a good removal of organic, ammonia and turbidity could be achieved, and the effluent quality complied with a discharge standard. It shows that MBR is a promising technology for Wastewater treatment.
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