Ultrafiltration with in-line coagulation for the removal of natural humic acid and membrane fouling mechanism

作     者：WANG Jin WANG Xiao-chang 

作者机构：Department of Municipal and Environmental Engineering Beijing Jiaotong University Beijing 100044 China School of Environmental and Municipal Engineering Xi＇an University of Architecture and Technology Xi＇an 710055 China 

出 版 物：《Journal of Environmental Sciences》 (环境科学学报（英文版）)

年 卷 期：2006年第18卷第5期

页      面：880-884页

核心收录：

学科分类：083002[工学-环境工程] 0830[工学-环境科学与工程（可授工学、理学、农学学位）] 08[工学] 

基　　金：The National Natural Science Foundation of China (No. 50138020) 

主　　题：natural humic acid ultrafiltration (UF) in-line coagulation high performance liquid chromatography (HPLC) membrane fouling 

摘      要：Experimental and theoretical analysis were made on the natural humic acid removal and the membrane fouling of ultrafiltration （UF） with in-line coagulation. The results showed dissolved organic carbon （DOC） and UV254 removals by the UF with in-line coagulation at pH 7 were increased from 28% to 53% and 40% to 78% in comparison with direct UF treatment respectively. At the same time, the analysis of high performance liquid chromatography showed that UF with coagulation had significant improvement of removal of humic acid with molecular weights less than 6000 Da in particular. Compared to direct UF, the in-line coagulation UF also kept more constant permeate flux and very slight increase oftransmembrane pressure during a filtration circle. Two typical membrane fouling models were used by inducing two coefficients Kc and Kp corresponding to cake filtration model and pore narrowing model respectively. It was found that membrane fouling by pore-narrowing effect was effectively alleviated and that by cake-filtration was much decreased by in-line coagulation. Under the condition of coagulation prior to ultrafiltration at pH 7, the cake layer formed on the membrane surface became thicker, but the membrane filtration resistance was lower than that at pH 5 with the extension of operation time.