Three different hollow-fibre ultrafiltration (UF) membranes were applied to treat upflow biological activated carbon (UBAC) effluent to determine the characteristics of membrane biofouling by microorganisms and particles. At the beginning of filtration, the cake layer formed on the membrane was loose and highly compressible, and the trans-membrane pressure (TMP) rapidly increased. When compressed to a certain extent, cake layer with low compressibility was formed by the accumulated particles and resulted in slower TMP increment. Thus, the decreased compressibility of the cake layer formed on the UF membrane during filtration of UBAC effluent led to the rapid increase in TMP at the beginning and slow increment in subsequently. The results were confirmed by filtering Escherichia coli, Staphylococcus aureus and kaolinite mixed suspensions with flat-sheet UF membrane. Our findings provide a new insight into membrane biofouling control and may facilitate better membrane application in drinking water treatment.

三种不同的中空纤维超滤（UF）膜用于处理上流生物活性炭（UBAC）流出物，以确定膜被微生物和颗粒生物污染的特性。在过滤开始时，在膜上形成的滤饼层是疏松的且高度可压缩的，并且跨膜压力（TMP）迅速增加。当压缩到一定程度时，堆积的颗粒形成低压缩性的饼层，导致TMP的增加较慢。因此，在UBAC流出物的过滤过程中，在UF膜上形成的滤饼层的可压缩性降低导致TMP在开始时迅速增加，而在随后缓慢增加。通过过滤大肠杆菌证实了结果，带有平板超滤膜的金黄色葡萄球菌和高岭石混合悬浮液。我们的发现为膜生物污染控制提供了新的见解，并可能有助于在饮用水处理中更好地应用膜。