膜生物反应器处理洗车废水中操作压力及环境因素对膜过滤性能的影响

通过膜生物反应器(MBR)处理某车辆厂洗车废水的实验研究,结合理论计算,分析了操作压力及环境因素对膜过滤性能的影响.研究结果表明,在低压区,膜本身阻力占主导地位,它与操作条件无关;在中压区,浓差极化阻力占主导地位,它与其他操作条件关系密切;在高压区,凝胶层阻力占主导地位,操作压力增加对膜通量影响不大,在此阶段膜分离特性还与污泥浓度、膜面流速等操作条件有关.所以,采用膜反应器处理洗车废水,在MBR中存在一个临界压力,当操作压力高于临界压力时,膜通量随操作压力变化不大,而膜表面污染却明显加剧.因而设计膜生物反应器时,操作压力是一个重要的参数.此外.还研究了温度、pH值、水力停留时间等环境影响因素对膜过滤性能的影响.

Effects of operating pressure and environmental factor on membrane's filtration function during the treatment of car-washing wastewater with a membrane bioreactor

The treatment of car-washing wastewater by using membrane bioreactor (MBR) was investigated. The influences of operating pressure and environmental factors on the membrane's filtration function were analyzed combining with theoretical calculations. In the meiobar range, membrane resistance was the dominant role, independent of operating terms. In the middle pressure range, concentration difference-polarized resistance was the dominant role, depending much on operating terms. In the high pressure range, gelatin resistance was the dominant role. The influences of the operating pressure was small on the membrane flux, and the membrane's separating characteristics were related much with mud concentration, membrane flow velocity and etc. This study showed that when MBR was used to dispose car-washing wastewater, there was a critical pressure in MBR. When the operating pressure was higher than the critical pressure, the membrane flux was changed slightly, but membrane surface pollution was increased distinctly. Therefore when MBR was designed, the operating pressure was a key parameter. The influences of environmental factors such as temperature, pH and hydraulic retention time on the membrane's filtration function were investigated.