Membrane cleaning was investigated on fouled membranes supplied by a power plant. The chemical composition and the distribution of contaminants were analyzed by optical microscope, scanning electron microscope(SEM) , Fourier transform infrared spectroscopy (FTIR) , and energy dispersive X-ray spectroscopy(EDX). Results showed that the ultrafiltration existed organic and inorganic contaminants. The outer layer consists mainly of inorganic substances and the inner layer consists organic ones. Various chemicals were explored for their cleaning effects including HCl, NaOH, EDTA and NaClO. Ethylene di-amine tetraacetic acid (EDTA) and NaClO showed higher flux recovery. The cleaning time and the temperature were further optimized for EDTA and NaClO systems. The combination of EDTA and NaClO and their application sequence were compared. Results showed that cooperative effects on combination of EDTA and NaClO with flux recovery depended on the cleaning sequence. The highest flux of 1 780 L/(m2·h) was observed when the membranes were treated with EDTA followed by NaClO treatment.%以某电厂的超滤膜为研究对象,利用光学显微镜、扫描电镜(SEM)、EDX能谱仪、傅里叶红外光谱仪等表征仪器对污染后的膜形貌及膜污染物进行了表征分析.结果表明:超滤膜同时存在有机物污染和无机物污染,外表面主要为无机污染物,内表面主要为有机污染物.使用了HCl、NaOH、NaClO及乙二胺四乙酸(EDTA)等化学清洗剂对膜进行了化学清洗,发现经NaClO和EDTA清洗后,膜通量恢复较明显；并对NaClO和EDTA清洗体系的清洗温度和清洗时间进行优化.研究了NaClO和EDTA的组合清洗对膜通量恢复的影响.结果发现:NaClO和EDTA对膜清洗效果表现出协同作用,方案F清洗后能使膜通量恢复到最大值1 780 L/(m2·h).
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