| As different material,aperture and manufacturers,different membrane materials dealing with the same performance out of waste water separation characteristics of membrane water flux,contamination resistance,membrane water flux and attenuation coefficient may be different.In this paper,different membrane materials of MBR was applied to treat wastewater. Design principles for MBR system was discussed in order to develop a technologically and economically feasible MBR system.Also long-term membrane operational performance was monitored and studied in order to solve fouling and process parameters,improve cleaning problems,explore reasonable operational capacity,and promote the use of reference works. The results show as follows:The degree of fouling layer formed by different membrane material is different.1# PP membrane of the anti-pollution is better than 2# PVDF membrane.Through stepwise method, two different materials on the critical flux of the membrane were compared,experimental results show that 1# membrane of the critical flux is 5～6.25L/(m2·h),and 2#PVDF membrane of the criticak flux is 8.76～10.51L/(m2·h).In order to optimize MBR operating conditions,the following Orthogonal Design study results showed that the critical flux can be measured.Through the analysis of the influencing factors of membrane fouling by MLSS and EPS, The TMP increasing rate of 1# and 2# membrane was consistent with MLSS trend and 1# membrane was less then 2#,which indicated that the different membrane-modules had a different membrane fouling rate under the same conditions.By comparing the EPS content in supernatant and the mixture,it was found that the total EPS content in the mixture is higher than in the supernatant,this illustrate the mixture is more inclined to be fouled,EPS is the predominance pollutants which impact membrane flux.In the content of the mixture of polysaccharides was significantly higher than that of protein,polysaccharide is a hydrophilic polymer material,more easily attached to the film hole and the formation of the surface gel layer,pore blocking,reducing the effective membrane filtration area,resulting in flux decline in the formation of irreversible membrane fouling.In the experimental conditions,SVI value within the normal range,sludge has a well activity and settling capability,and the content of EPS was negatively correlated with SVI relationship.The Pollutant removal performance and mechanism of wastewater was analyzed in this experiment,the results showed conditions on COD removal efficiency,removal rate of CODcr on membrane is greater than on biological,while the removal efficiency on PVDF membrane is slightly better than the PP,and a stability changes,the removal rate of CODcr,NH3-N,and tubritidy are upwards of 85%,98%,and 98%respectively.And the turbidity of the effluent discharging completely superior to the national renewable standard. The major pollutant removal performance of 1#PP membrane was a little better than 2#PVDF.Through a group of test by means of orthogonal table,influence of membrane flux, suction time,suction suspended time and operating parameters of aeration rate on membrane filtration was investigated.When membrane flux under the critical flux,sludge can't assemble as sediment on the surface of membrane easily,suction pressure keep stabilization,membrane fouling can't happen or have a very slow progress.Shorter suction time,longer suspended time and larger aeration rate could alleviate membrane fouling,which influenced accumulation and back transportation of pollutants on and from membrane surface.The optimum operators parameters were membrane flux of 5 L/(m2·h),8 minutes of suction time,2 minutes of suction suspended time and aeration rate of 0.6 m3/h in this experimental conditions.The impact degree of those four factors on membrane fouling was descend, membrane flux was the key factor and aeration rate had the least impact on membrane fouling.
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