To remove the high organic pollutants and high salt ions of Nansi Lake water,a pilot study was conducted using ultrafiltration-nanofiltration process,and the treatment efficiency of two kinds of NF membrane (H membrane and G membrane)were compared.Experimental results show that the UF-NF hybrid system can remove organic matter and inorganic salt ions effectively. The inorganic salt ions removal rate of the two NF membranes was both above 90% and the DOC removal rate of H membrane and G membrane were 98.7% and 81.6%,respectively.By contrast, the effluent water quality of H membrane was much better than that of G membrane.The mem-brane flux of G membrane was higher than that of H membrane under the same condition (pressure and temperature),and the energy consumption of G membrane was lower than that of H mem-brane.At the inlet side of fouled NF membrane,the main fouling was organic pollution,while it was mainly inorganic salt scale at the outlet side.The membrane flux could be restored to more than 90% of the initial flux by chemical cleaning.However,there were still traces of organic mat-ter and inorganic salts on the membrane surface after cleaning,which was the main reason for the irreversible NF membrane fouling.%针对南四湖水源水中高有机物、高含盐量的特点,采用超滤-纳滤工艺进行了中试研究,对比分析了2种纳滤膜(H 膜、G膜)的处理效果.试验结果表明:超滤-纳滤双膜工艺可有效应对水源中存在的有机物和无机盐污染问题,2种纳滤膜对无机盐离子去除率在90%以上,H 膜与 G 膜对DOC的去除率的分别为98.7%和81.6%,H 膜出水水质优于 G 膜.相同压力和温度下 G 膜的通量要高于H 膜,同时单位产水量的能耗G膜也要低于H 膜;污染后的纳滤膜进水端主要是有机物污染,出水端主要是无机盐结垢.化学清洗可将膜通量恢复至初始通量的90%以上,但清洗后的膜面仍然存在微量的有机物和无机盐结垢,这是形成纳滤膜不可逆污染的主要原因.
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