基于鄱阳湖流域原水中有机物污染的纳滤膜对PPCPs的去除机理研究

The efficiency of the PPCPs removal by nanofiltration membrane was affected by many factors. Previous studies have shown that the presence of dissolved organic matter (DOM) such as humic acid has great influence on the retention of PPCPs for the complexe mechanism between DOM and PPCPs using a NF membrane. And there is not system theoretical explantion for the mechanism between DOM and PPCPs in the nanofiltration membrane filtration. Characteristics of raw water DOM is different from humic acid such as model pollutants, it is necessary to further investigate the influence of the raw water DOM on PPCPs removal using NF membranes. . The problem of drinking water security is directly reated to the water quality of river system into Poyang lake and Poyang lake for the Poyang lake Basin andlower reaches of the Yangtze river's. This study aimed to investigate the effects of natural DOM on PPCPs removal using NF membranes in the Poyan lake Basin, and to elucidate NF membrane fouling with respect to the interaction between PPCPs and the membrane surface. Characteristics and membrane fouling of raw water DOM, namely Poyang lake, Ganjiang river, Fu river, Xinjiang river, Rao river and Xiu river DOM, would be studied in this work. Mechanisms possibly accounting for the effects of membrane fouling on PPCPs rejection were systematically investigated and proposed combined with nanofiltration process. Simultaneously, the interaction mechanism of DOM foulant and membrane were analysed based on the XDLVO theory, which revealed the NF membrane fouling process by raw water DOM in the Poyan lake Basin.

原水中溶解性有机物（DOM）的存在对纳滤膜去除PPCPs的行为有重要影响。国内外研究者对腐植酸等模型污染物的研究结果表明，DOM和PPCPs之间作用机理复杂，DOM对纳滤膜去除PPCPs的影响规律无一致结论，目前尚无系统完整的理论解释。原水DOM特性不同于腐植酸等模型污染物，有必要进一步探索原水DOM对纳滤膜去除PPCPs的影响机制及其膜污染机理。. 鄱阳湖水系水质直接关系到鄱阳湖流域乃至长江中下游地区的用水安全。本课题主要研究鄱阳湖流域原水DOM对纳滤膜的污染机理及其对PPCPs去除的影响机制。以鄱阳湖流域原水作为研究对象，从研究原水DOM的特性出发，结合纳滤膜去除PPCPs的过滤试验，找出鄱阳湖流域原水DOM对纳滤膜去除PPCPs行为的影响规律及其膜污染的主要原因；同时，引入XDLVO理论解析原水DOM与纳滤膜的相互作用机制，揭示天然原水DOM对纳滤膜的污染过程和机理。

原水中溶解性有机物（DOM）的存在对纳滤膜去除PPCPs的行为有重要影响。鄱阳湖湖区和主要入湖河流均为江西当地以及鄱阳湖生态经济区重要的饮用水水源，通过鄱阳湖流域原水中DOM的特性分析和纳滤膜过滤研究，考察原水DOM对纳滤膜去除PPCPs物质的影响规律和纳滤膜的污染机理。研究表明鄱阳湖流域原水DOM以中小分子有机物为主，强疏和中亲组分占比较大。疏水性有机物组分对纳滤膜造成的通量衰减程度和衰减速率均高于相同分子量区间的亲水性有机物组分，亲水性有机物对膜通量衰减程度影响相对较小，疏水性有机物对膜通量衰减程度影响相对较大。原水DOM对膜通量影响较大的物质分别为大分子疏水性有机物和小分子亲水性有机物。通过测试分析鄱阳湖湖区和赣江、抚河、信江、饶河、修河五大入湖河流等原水中PPCPs物质的赋存水平，研究发现鄱阳湖湖区及主要入湖河流中存在水平相对较高的PPCPs有CAF、CBZ、SDZ、DCF、AMX、TC和IBP。原水DOM的污染在纳滤膜表面形成致密的滤饼层，膜孔尺寸减小，筛分作用增强，阻碍了PPCPs通过纳滤膜，纳滤膜表面局部高浓度PPCPs溶液形成浓差极化现象，加速PPCPs通过纳滤膜。XDLVO理论更适用于预测发生在膜表面的污染或渗透通量较小时的膜污染机理。鄱阳湖流域原水中疏水性有机物对纳滤膜通量造成的衰减程度大于亲水性有机物，在膜表面形成的污染层更密实，膜与有机污染物间的AB作用能和有机污染物与有机污染物间的AB作用能对这一现象起决定性作用。研究成果对江西地区等供水水质的提高和饮用水水质安全的保证具有重要的理论和实际指导意义。