改性PVDF膜在MBR中膜污染的研究

Research on membrane fouling of modified PVDF membrane in membrane bioreactor

将聚偏氟乙烯膜磺化6 h,在TiO_2胶体溶液中浸泡20min,制得的TiO_2改性膜纯水通量约为1 800L/m^2·h,高出未改性膜250L/m^2·h。通过膜生物反应器中膜阻力的测定,分析膜污染形成的原因,表明膜污染主要是浓差极化层及凝胶层引起的;通过活性污泥对膜污染机理的研究,判断出污泥的过滤过程严格符合沉积过滤定律。在膜生物反应器(MBR)中运行时,TiO_2改性膜稳定通量高于未改性膜,总阻力低于未改性膜;通过扫描电镜分析,TiO_2改性膜沉积层的厚度比未改性膜薄,表明TiO_2改性膜的抗污染性能优于未改性膜。

When PVDF membrane was sulfonated for 6 hours with immersion in TiO2 colloidal solution for 20 minutes,the pure water flux of modified membrane was nearly 1 800 L/m^2· h, which was 250 L/m^2· h higher than unmodified. According to results of the membrane resistance determination in a membrane bioreactor（MBR）,it was found that membrane fouling was mainly attributed to concentra- tion polarization layer and gel layer. Base on the membrane fouling mechanism, it also found that sludge filtration process basically abided by the deposition filtration law. In the MBR, the stable flux was in the increasing order：membrane modified by TiO2 〉 unmodified membrane, and the total resistance was in the decreasing order：membrane modified by TiO2 〈 unmodified membrane. Analysis with scanning electron microscopy indicated the deposition layer thickness was in the decreasing order： membrane modified by TiO2% unmodified membrane. It was concluded that anti-fouling performance of modified membrane was better than that of unmodified.