不同超滤膜处理二级出水的膜污染机制研究

Study on the membrane fouling mechanisms of secondary effluent treatment by ultrafiltration with different characteristics

为探究截留分子量与材质对污染物的去除效果,并分析二者对抗污染性能的影响,使用不同材料(PES、PVDF)和不同截留分子量(50,100 kDa)的超滤膜处理二级出水。结果表明,对于溶解性有机物(DOC)的去除效果,相同材料,截留分子量为50 kDa超滤膜优于100 kDa;100 kDa的超滤膜,PES材料优于PVDF。材料相同,100 kDa超滤膜膜通量下降程度小,反冲洗后,膜通量恢复程度越好,可逆污染占比较大;孔径相同,PES超滤膜的膜通量下降较慢,反冲洗效果更好,不可逆污染更轻。膜污染模型分析中,材料相同,100 kDa膜片对4种污染模型的拟合系数均高于50 kDa,4种污染模型造成的污染更加显著,膜污染过程更加复杂。

In order to study the influence of materials and molecular weight on the pollutants removal effects,and to analyze their influence on anti-pollution performance,different materials(PES,PVDF)and different molecular weight(50,100 kDa)ultrafiltration membranes were used to treat the secondary effluent their membrane fouling mechanisms.The results showed that,for the removal effect of DOC,50 kDa UF membrane was better than 100 kDa with the same material.The PES material had better effect on the removal of DOC than PVDF when the molecular weight was 100 kDa.For the same material,100 kDa UF membrane the decreased slowly.After backwashing,the flux recovery of 100 kDa UF membrane was superior to 50 kDa with not serious irreversible pollution.For the UF membranes with the same molecular weight,the specific flux of the PES decreased slowly,of which the backwashing effect was better while the irreversible membrane pollution was not serious.In the membrane fouling model analysis,the fitting degree of 100 kDa UF membrane was higher than that of 50 kDa.With the molecular weight increasing,the membrane fouling caused by four filter model was more notability and the membrane fouling process was more complicated.