絮体结构、胶体颗粒物、天然有机物对微滤和超滤膜污染的影响
文献类型：学位论文
| 作者 | 赵冰清 |
| 学位类别 | 博士 |
| 答辩日期 | 2010 |
| 授予单位 | 中国科学院研究生院 |
| 授予地点 | 北京 |
| 导师 | 王东升 ; 汤鸿霄 |
| 关键词 | 絮体结构 胶体颗粒物 天然有机物 膜污染 微滤 超滤 |
| 中文摘要 | 膜分离技术是近几十年迅速发展起来的一种高效分离技术，被誉为“21世纪的水处理技术”，目前已广泛应用于在硬水软化、海水淡化、水和废水处理及回用等方面。但在实际工程应用中，膜污染制约了膜技术的推广和应用。本文以微滤和超滤为研究对象，从絮体结构、胶体和有机物角度对不同膜污染机制做了深入的研究和探讨，得出以下主要结论： （1）混凝剂的铝形态分布对调控形成的絮体结构有显著影响。然而对大分子腐殖酸和小分子的对羟基苯甲酸的影响结果有所不同。大分子腐殖酸体系中，相同混凝剂投药量下，不同混凝剂形成的絮体粒度大小顺序依次为PACla > PAClp > PAClb，与混凝剂中的Ala含量正相关; 絮体的分形维数接近；絮体的强度顺序依从PACla > PAClb > PAClp。小分子对羟基苯甲酸体系中，三种混凝剂所形成絮体的粒度大小顺序为PACla > PAClc > PAClb, 分形维数大小顺序为PAClb > PAClc > PACla, 强度大小顺序依次为PAClc > PAClb > PACla。PACla作为混凝剂制备的絮体其通量结果整体好于其他PACls。 （2）对于可压缩性絮体过滤而言，絮体强度对膜通量影响显著。絮体的强度常数和滤饼的可压缩性系数间线性正相关。 （3）絮体过滤时，絮体结构决定膜通量。混凝过程既可能提高膜通量也可能加重膜污染，而混凝剂的投加量是决定混凝-膜过滤组合工艺效果的关键参数，滤饼质量或无机颗粒物的浓度影响很有限。当发生严重膜孔堵塞时，膜孔堵塞的程度决定膜通量。 （4）通过实际原水水样处理试验，发现在台湾宝山水库原水试验导致超滤膜污染的物质同时包含腐殖酸、多糖、酪氨酸类蛋白以及含Si-O-的无机物质。腐殖酸是导致不可逆膜污染的主要成分，尤其是疏水性组分。NaOH对薄膜的化学清洗效果最好，HCl只对酪氨酸类蛋白洗脱有效。在PVC合金中空纤维膜处理长江原水的研究中发现，蛋白类有机物和硅胶体类物质是导致不可逆膜污染的主要物质。NaOH对膜污染物质清洗效果最好，洗脱出的有机物量最多。 |
| 英文摘要 | Membrane processes are highly efficient separation technology developing rapidly in recent decades，and is expected to be the prevalent water treatment technology for the 21st century. It has been widely used in water softening, desalination, water and wastewater treatment and resuse. However, membrane fouling is the main problem of membrane technology encountered in practical engineering applications. The effect of floc structure on membrane fouling and fouling mechanisms of natural organic matter, colloidal particles and natural organic matter were investigated in this study. The results were outlined as follows: (1) The aluminum species distribution of coagulant has significant impact on floc characteristics. However, the effects on coagulation of high molecular weight humic acids and low molecular weight p-hydroxybenzoic acid were different. For humic acids model system, the floc sizes from different coagulants were in the following order PACla > PAClp > PAClb, which was consistent with the amount of Ala species in PACls. The fractal dimension value was similar for each PACls. The floc strength was of the following order: PACla > PAClb > PAClp. As for p-hydroxybenzoic acid model system, the floc size order was PACla > PAClc > PAClb. Fractal dimension value order was PAClb > PAClc > PACla. And the floc strength order was PAClc > PAClb > PACla. Membrane fluxes of PACla-flocs were better than that of other PACls。 (2) As for compressible flocs, floc strength is the key parameter influencing cake resistance of membrane filtration. There is a positive linear correlation between floc strength constant and cake compressibility index. (3) For direct filtration of floc suspensions, floc structure determined the membrane flux. Coagulation can either improve membrane flux or enhance membrane fouling. Coagulant dosage is a critical parameter which determines the performance of coagulation-direct microfiltration hybrid process. When pore plugging took place, the degree of pore blockage determined the membrane flux. (4) Through real water treatment test, it was found that the membrane foulant for ultrafiltration of Baoshan Reservoir water in Taiwan included both humic acid, polysaccharides, proteins and inorganic clay with Si-O- group. Humic acid was the main irreversible foulant, especially the hydrophobic fraction. NaOH exhibited the best cleaning efficiency while the HCl was effective for only proteins. While for PVC UF membrane treatment of Yangtze River water, it showed that protein and Colloidal silicas were main irreversible foulant. NaOH desorbed more organic foulant than HCl. |
| 源URL | [http://ir.rcees.ac.cn/handle/311016/35059]  |
| 专题 | 生态环境研究中心_环境水质学国家重点实验室 |
| 推荐引用方式 GB/T 7714 | 赵冰清. 絮体结构、胶体颗粒物、天然有机物对微滤和超滤膜污染的影响[D]. 北京. 中国科学院研究生院. 2010. |
入库方式： OAI收割
来源：生态环境研究中心
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