采用超滤膜错流过滤稀土冶炼萃取废水，对污染物的处理效率和膜污染特征进行了研究。通过设计膜阻构成实验，测算膜污染总阻力及其构成比例，结果表明膜自身阻力（Rm）相对较高，膜污染阻力以沉积层阻力（Rc）和堵塞阻力（Rf）为主，浓差极化阻力（Rp）较弱。考察了膜通量随时间和跨膜压差变化规律，以及超滤膜对污染物的截留效率，当跨膜压差为0.1-0.5MPa时，COD和浊度平均去除率分别为26.5%和77.7%。SEM-EDX分析发现膜面有大量颗粒物和结晶物等污染物，Na、Ca、Cl和S为主要无机元素。采用纯水、HCl、NaOH、NaClO和EDTA五种清洗液对污染膜进行了清洗，对洗脱液组成、污染膜和清洗膜的形貌特征进行了分析，结果表明酸洗对无机金属离子有着较好的去除效果，碱洗对有机物尤其是腐殖酸类和芳香族化合物的去除效果较佳。

In this study, the UF membrane was used to treat rare earth smelting wastewater by cross-flow filtration. The treatment efficiency and the characteristics of fouled membrane were studied. Then the total resistance of the membrane fouling and its composition were calculated.
The results showed that the proportions of membrane intrinsic resistance (Rm) was relatively high.
Membrane fouling resistance was mainly composed by cake layer resistance (Rc) and pore blocking resistance (Rf), and the concentration polarization resistance (Rp) was weak. The treatment efficiency of ultrafiltration membrane, and the differerce permeate flux on filtrate time and transmembrane pressure were investigated . When the transmembrane pressure was 0.1-0.5MPa, the average removal rates of COD and turbidity were 26.5% and 77.7%, respectively. SEM-EDX analysis results revealed that there were a large number of particulate matter and crystalline substances in the film surface, and Na, Ca, Cl, and S were the main inorganic elements. Finally, five different types of chemical cleaning reagents: pure water, HCl , NaOH, NaClO,and EDTA solutions, respectively,were used to clean the fouled membrane. Then the composition of eluants, the morphology of fouled membrane and cleaning membrane were analyzed.The results showed that 0.1mol/L HCl had better removal effect on inorganic metal ions, while 0.1mol/LNaOH had better removal effect on organic compounds, especially for humic acids and aromatic compounds.

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