基于小孔径PVDF内衬膜A/O-MBR膜污染分析

为研究膜生物反应器膜污染问题,在缺氧-好氧一体式膜生物反应器中,对模拟生活污水的处理效果进行考察,考察了4种不同孔径聚偏氟乙烯(PVDF)内衬膜对膜污染的影响规律。结果表明,基于小孔径PVDF膜的MBR工艺对模拟生活污水中COD、NH3-N的去除率分别达到96%、90%,出水浊度在0.35 NTU以下;在操作条件固定的情况下,随着膜孔径增加,临界通量逐渐降低;孔径越小,跨膜压差上升越缓慢,膜污染较轻。膜污染模型分析结果显示:无论何种孔径的膜,在MBR系统中,滤饼层和凝胶层污染所占的比例都最大(>80%),因此,在使用过程中减缓滤饼层及凝胶层的形成至关重要。

Study on Membrane Fouling of Reinforced PVDF Membrane with Small Pore Size in A/O-MBR Process

In order to research the membrane fouling problems in MBR,the simulated domestic wastewater treatment efficiency by A/O-MBR was investigated,and the influence rule of four kinds of reinforced PVDF membranes with different pore sizes on membrane fouling were studied.The results showed that,the removal rate of COD and NH3-N in simulated domestic wastewater by MBR process based on reinforced PVDF membrane reached 96%and 90%,respectively,and the effluent turbidity was below 0.35 NTU.In the case of fixed operating conditions,the critical flux decreased gradually with the increase of membrane pore size;the smaller the pore size,the slower the upper body of the transmembrane pressure difference and the less the membrane fouling.The results of the membrane fouling model analysis showed that,regardless of the pore size of the membrane,in the MBR system,the filter cake and gel layer contamination accounts for the largest proportion of membrane fouling(>80%),thus slowing the formation of the cake layer and the gel layer during using is very important.