Abstract To unravel fouling and defouling mechanisms of protein, saccharides and natural organic matters (NOM) on polymeric membrane during filtration, this study investigated filtration characteristics on polyvinyl chloride (PVC) ultrafiltration membranes with bovine serum albumin, dextran, humic acid as model foulants. Membrane fouling and defouling performances were analyzed through monitoring the flux decline during filtration and flux recovery during physical backwash. Physico-chemical properties (e.g., hydrophobicity and surface charge) of PVC membrane and foulants were characterized, which were used in the extended Derjaguin–Landau–Verwey–Overbeek (EDLVO) theory to calculate the interaction energies between membrane-foulant and foulant-foulant. The results showed that at the later filtration stages the fouling rate was strongly correlated with the deposition rate, which was determined by the interaction energy profile calculated by EDLVO. Moreover, the adhesion forces of membrane–foulant and foulant–foulant were further measured by atomic force microscopy (AFM) with modified colloidal probes. A positive correlation (R2 = 0.845) between particle detachment rate (determined by adhesion force) and defouling rate was developed for BSA and HA foulants that led to cake layer formation. By contrast, dextran defouling rate was off this correlation as dextran partially clogged membrane pores due to its smaller size.

中文翻译：

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聚氯乙烯 (PVC) 超滤膜污染和去污行为：EDLVO 理论和界面粘附力分析

摘要 为了阐明蛋白质、糖类和天然有机物（NOM）在过滤过程中对聚合物膜的污染和去污机理，本研究以牛血清白蛋白、葡聚糖、腐植酸为模型污染物，研究了聚氯乙烯（PVC）超滤膜的过滤特性。通过监测过滤过程中的通量下降和物理反洗过程中的通量恢复来分析膜污染和去污性能。表征了 PVC 膜和污垢物的物理化学性质（例如疏水性和表面电荷），这些特性用于扩展的 Derjaguin-Landau-Verwey-Overbeek (EDLVO) 理论，以计算膜-污垢物和污垢物-污垢物之间的相互作用能. 结果表明，在过滤后期，污垢率与沉积率密切相关，这是由 EDLVO 计算的相互作用能分布决定的。此外，膜-污垢和污垢-污垢的粘附力通过原子力显微镜（AFM）和改性胶体探针进一步测量。对于导致滤饼层形成的 BSA 和 HA 污垢，粒子脱离率（由粘附力决定）和去垢率之间存在正相关（R2 = 0.845）。相比之下，葡聚糖去污率与这种相关性无关，因为葡聚糖由于其较小的尺寸而部分堵塞了膜孔。膜-污垢和污垢-污垢的粘附力通过原子力显微镜（AFM）和改性胶体探针进一步测量。对于导致滤饼层形成的 BSA 和 HA 污垢，粒子脱离率（由粘附力决定）和去垢率之间存在正相关（R2 = 0.845）。相比之下，葡聚糖去污率与这种相关性无关，因为葡聚糖由于其较小的尺寸而部分堵塞了膜孔。膜-污垢和污垢-污垢的粘附力通过原子力显微镜（AFM）和改性胶体探针进一步测量。对于导致滤饼层形成的 BSA 和 HA 污垢，粒子脱离率（由粘附力决定）和去垢率之间存在正相关（R2 = 0.845）。相比之下，葡聚糖去污率与这种相关性无关，因为葡聚糖由于其较小的尺寸而部分堵塞了膜孔。