Ultrafiltration technology (UF) is efficient in surface water treatment, but its development and widespread application are limited by membrane fouling. Herein, an efficient and stable polymerized ferric titanium coagulant (PFTC) was synthesized and used as a UF pretreatment agent in actual lake water treatment. The control mechanism of PFTC on membrane fouling was investigated from the perspective of organic removal efficiency and in-situ membrane surface regulation. PFTC demonstrated a remarkable affinity for soluble metabolic intermediates and hydrophilic proteins through complexation and hydrogen bonding force, achieving removal efficiencies of 66.4 % for UV254 and 81.3 % for DOC, respectively. The hydrophilic pollutants with high molecular weight and non-saturated structure could be preferentially removed by PFTC due to its diverse hydrolysates including positively charged Fe-based hydrolysates, amorphous Ti-based hydrolysates, and highly polymerized Fe-Ti copolymers. The flocs generated by PFTC exhibited strong hydrophilicity, allowing for the formation of a loose porous cake layer on the ultrafiltration membrane, which acted as a hydrophilic layer to enhance the anti-fouling performance of ultrafiltration membrane. With its dual function of contaminant removal and in-situ membrane surface regulation, PFTC alleviated 98.9 % of membrane fouling. This study provides new insights into membrane fouling control by coagulation pretreatment and efficient treatment of surface water.

中文翻译：

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一种基于使用复合混凝剂的预处理缓解和原位膜表面调节相结合的膜污染控制策略


超滤技术 （UF） 在地表水处理中很有效，但其发展和广泛应用受到膜污染的限制。在此，合成了一种高效稳定的聚合钛铁混凝剂 （PFTC），并在实际湖泊水处理中用作 UF 预处理剂。从有机物去除效率和原位膜表面调节的角度研究了 PFTC 对膜污染的控制机制。PFTC 通过络合和氢键合力对可溶性代谢中间体和亲水性蛋白质表现出显著的亲和力，UV254 和 DOC 的去除效率分别为 66.4% 和 81.3%。PFTC 水解物种类繁多，包括带正电荷的 Fe 基水解物、无定形 Ti 基水解物和高度聚合的 Fe-Ti 共聚物，因此可以优先去除具有高分子量和非饱和结构的亲水性污染物。PFTC 生成的絮凝物表现出很强的亲水性，允许在超滤膜上形成松散的多孔滤饼层，该滤饼层充当亲水层，以增强超滤膜的防污性能。凭借其去除污染物和原位膜表面调节的双重功能，PFTC 减轻了 98.9% 的膜污染。本研究为通过混凝预处理和地表水的有效处理来控制膜污染提供了新的见解。