Abstract: Comparing with coagulation membrane filtration(C-MF) process, the circulating flocculation membrane filtration (CF-MF) process is a combination of circulating contact flocculation with membrane filtration. The differences of membrane fouling development in the two processes were investigated in this study. SUVA was used as an evaluation index of hydrophilic/hydrophobic properties for organic matters to assess the effect of process variation on SUVA as well as to find relation between SUVA and index of comprehensive membrane fouling. The results indicated that there exists a good liner relationship between SUVA in membrane filtration and membrane fouling. The higher SUVA was, the more serious membrane fouling was. In the optimal operation conditions, SUVA in membrane filtration effluent and coagulation process supernatant were 1.74 L·mg^-1·m^-1 and 1.18 L·mg^-1·m^-1 for CF-MF process, the removal of organic matters increased by 17% and 29%, comparing with C-MF process, indicating that the removal of hydrophobic organic matters and the control of fouling formation on membrane from them was better for CF-MF than C-MF. Comparing with C-MF process, the CF-MF is more effective for removing organic matters. With coagulant dosing of 6 mg·L^-1 and reflux floc concentration of 10 mg·L^-1, the removal rate of UV₂₅₄ and DOC were 58.75% and 49.7% respectively.

Key words: circulate flocculation, coagulation, filtration, membranes fouling, scale ultraviolet absorbance, unified membrane filtration index

摘要： 将循环接触絮凝与膜过滤相结合组成循环接触絮凝-膜过滤（CF-MF）工艺，以传统混凝-膜过滤（C-MF）工艺为对照，考察两种工艺在延缓膜污染方面的差异。采用比紫外吸光度（SUVA）作为有机物亲/疏水特性的评价指标，分析工艺变化对SUVA的影响以及SUVA和综合膜污染指数（UMFI）之间的内在联系。结果发现，膜出水SUVA与膜污染呈很好的相关性，出水SUVA越高，膜污染越严重；在最佳工艺条件下，CF-MF出水和混凝上清液SUVA分别达到了1.74 L·mg^-1·m^-1和1.18 L·mg^-1·m^-1，去除率与C-MF工艺相比分别提高17%和29%，说明CF-MF工艺对水中疏水性物质的去除效果比C-MF更好，能够有效控制疏水性物质对膜形成的污染；与C-MF相比，CF-MF能够更有效地去除水中的有机物，当混凝剂氯化铁投加量为6 mg·L^-1、回流絮体浓度为10 mg·L^-1时，UV₂₅₄和DOC的去除率分别达到了58.75%和49.7%。

关键词: 循环絮凝, 混凝, 过滤, 膜污染, SUVA, UMFI