Effect of seasonal variation of natural organic matter on the fouling of hydrophilic ultrafiltration membranes

The seasonal variation of distinct constituents of natural organic matter (NOM) in the two surface water sources (BIT Lake and ZGC River), as well as their impact on the fouling of hydrophilic ultrafiltration (UF) membranes, was explored in this work. Two kinds of hydrophilic UF membranes, comprising a commercial poly(ether sulfone) (PES) membrane (organic polymer membrane) and a kaolin membrane (inorganic ceramic membrane) characterized by low-cost, environmentally friendly, and highly permeable, were employed to explore the effect of NOM seasonal variation on UF membrane fouling. The findings revealed that the concentration of protein-like and polysaccharide-like substances in the two surface water sources exhibited a seasonal trend of summer > autumn ≈ spring > winter, while that of humic-like substances was autumn > winter > spring > summer. Seasonal variation in the trend of membrane fouling and flux recovery was identical between kaolin and PES membranes, and the magnitude of the effects followed a seasonal pattern of summer > autumn ≈ spring > winter, demonstrating that protein-like and polysaccharide-like substances were the primary fouling contaminants, and their impact was reversible due to the formation of a cake layer on the membrane surface, unlike that caused by humic-like substances (irreversible fouling formed by blocking membrane pores). In addition, the kaolin membrane outperformed the PES membrane in terms of antifouling performance. This investigation unveils the potential of the kaolin membrane for efficient surface water treatment, offering an economic, environmentally friendly, efficient, and scalable strategy for surface water treatment.