二级出水微滤过程中对醋酸纤维素酯膜的有机污染特征

Characterization of organic fouling on cellulose acetate membrane during microfiltration of secondary effluent and model solutions

低压膜过滤技术(包括微滤和超滤)在再生水生产领域正引起越来越广泛的关注。然而如何解决低压膜过滤过程中的膜有机污染问题始终是膜技术所面临的技术挑战。本研究采用醋酸纤维素酯微孔滤膜对二级出水溶解性有机物(EfOM)及其不同亲疏水性组分、蛋白模拟溶液、腐殖酸(HA)等进行恒流过滤实验。对不同有机物污染后的膜表面使用全反射傅立叶红外光谱(ATR-FTIR)和X射线电子能谱(XPS)进行表征。结果表明,相对于蛋白质和EfOM等,HA所造成的膜污染最少。ATR-FTIR的结果同时显示,以官能团而言,更多的氨化物(1535cm-1)、脂肪族物质(2860～2970cm-1)和氢氧根(3400cm-1)存在于膜表面。TMP/V数据比较结果表明,在EfOM各亲疏水性组分、蛋白质和HA的对比中,EfOM中的疏水碱性物质(HPO-B)对膜污染的贡献最大,而HA的膜污染贡献最小。UVA和荧光激发-发射光谱(FEEM)结果表明,HPO-B和蛋白质对醋酸纤维素酯膜的污染贡献较大。综合不同分析手段可以对不同有机物造成膜污染的潜能大小得出如下排序:HPO-B>蛋白质>HPO-A、HPI>HA。

Low pressure membrane technology,including microfiltration and ultrafiltration,is being applied more and more in the wastewater reclamation.However,membrane fouling,especially fouling resulted from organic materials,stays a technical obstacle.In this study,the filtration experiments were performed with cellulose acetate microfiltration membrane,under constant-flux filtration mode.Secondary effluent organic matter（EfOM for short）,EfOM fractions based on hydrophilic-hydrophobic property,model protein solution（BSA）,humic acid were used for microfiltration experiments.Based up on the observation by using ATR-FTIR and XPS,humic acid possesses the least fouling potential among all organics used.In terms of functional groups,ATR-FTIR suggests that more amide（1 535 cm-1）,aliphatic C-H（2 860～2 970 cm-1）,and hydroxyl（3 400 cm-1） on membrane surfaces after filtration of BSA,EfOM,and hydrophobic part of EfOM.Comparing TMP/V,hydrophobic-basic EfOM possesses the greatest fouling potential and humic acid possesses the least fouling potential.And UVA and EEM results suggest that hydrophobic-basic EfOM and protein contributes a lot to cellulose acetate membrane fouling.