膜法生产饮用水过程中膜生物污染研究

发布时间：2018-04-24 00:35

本文选题：膜生物污染 + 微生物　；参考：《沈阳师范大学》2012年硕士论文

【摘要】：随着工业化进程的加速，水源污染、水质复杂化，造成了饮水安全隐患。与此同时，我国人民生活水平的日益提高，饮用水的安全问题也备受关注。而使用传统水处理工艺对饮用水的消毒过程中，消毒剂会产生各种消毒副产物。消毒剂通过与水中的天然有机物、溴化物、碘化物等发生取代或加成反应生成的消毒副产物大多数都被证实是致畸形、基因突变以及致癌的。膜分离技术为新式的饮用水处理工艺的研究与应用提供了条件，其有占地面积小、出水水质稳定、可进行自动控制等优点。但是膜污染问题严重影响着该技术的广泛应用，，膜污染不只提升了膜法制取饮用水的技术成本，还造成了膜透性的降低，而水通量降低制约着水生产的量。膜污染中的微生物污染是十分复杂的，因为生物种类多样繁殖能力以及对环境适应能力强，代谢产物以及次生产物多样都造成了生物污染的难以控制。本论文研究了在地表水生产饮用水过程中超滤膜和纳滤膜的不同微生物污染情况，通过分子生物学手段研究不同过滤时间的主要污染生物种类，对比了膜表面微生物在不同过滤时间的动态变化。辅助以膜的水通量以及水质变化等条件进行膜污染情况研究，主要得出以下结论：超滤膜和纳滤膜对水中生物都有很好的去除作用，其中纳滤膜因为其孔径小比超滤膜对微生物表现出了更好的截留能力。通过膜表面可培养微生物的测序分析结果得出超滤膜过滤前期的主要菌为芽孢杆菌属、微球菌属、假单胞属细菌。提取不同时期污膜上微生物DNA进行PCR-DGGE分析以及切带测序我们发现超滤膜上最早的优势污染菌为变形菌纲柄细菌属以及杆菌属细菌。在纳滤中变形菌纲、杆菌属的细菌也表示出了对界面的更多趋向性，除此之外假单胞属细菌也表现出了产生优势污染的倾向。扫描电镜对污膜表面污垢层检测结果显示，超滤膜的长期污染表现为网状粘连结构的污染层，污垢层中有各种微生物的分布。而纳滤膜的短期污染主要表现为颗粒状的大分子团，而长时间过滤之后也有粘连结构的出现。
[Abstract]:With the acceleration of industrialization, water pollution and water quality become more complicated, which leads to the hidden trouble of drinking water safety. At the same time, with the improvement of people's living standard, the safety of drinking water has been paid more and more attention. In the process of disinfecting drinking water by traditional water treatment process, disinfectants produce various disinfection by-products. Most of the disinfection by-products produced by disinfectant by substitution or addition reaction with natural organic matter, bromine and iodide in water have been proved to be deformed, mutated and carcinogenic. Membrane separation technology provides conditions for the research and application of new drinking water treatment technology, which has the advantages of small area, stable effluent quality and automatic control. However, the problem of membrane fouling seriously affects the wide application of the technology. Membrane fouling not only increases the technical cost of making drinking water by membrane method, but also results in the decrease of membrane permeability, and the decrease of water flux restricts the amount of water production. The microbial fouling in membrane fouling is very complicated because of the diversity of species and adaptability to the environment and the diversity of metabolites and secondary products which make it difficult to control the biological pollution. In this paper, the microbial contamination of ultrafiltration membrane and nanofiltration membrane in the process of surface water production for drinking water was studied, and the main species of contaminated organisms at different filtration times were studied by molecular biological methods. The dynamic changes of microbes on membrane surface at different filtration time were compared. The main conclusions are as follows: (1) the membrane fouling is studied by the water flux and water quality change of the membrane. Both ultrafiltration membrane and nanofiltration membrane have good removal effect on organisms in water. Nanofiltration membrane has better ability to intercept microorganism because of its small pore size than ultrafiltration membrane. The main bacteria in the early stage of ultrafiltration membrane filtration were Bacillus, Micrococcus and Pseudomonas. The DNA of microorganism extracted from sewage membrane at different periods was analyzed by PCR-DGGE and sequenced. We found that the earliest dominant fouling bacteria on ultrafiltration membrane were Proteus stipe and Bacillus. In nanofiltration, Proteus bacteria also showed more tendency to interface, and Pseudomonas bacteria also showed a tendency to produce dominant pollution. The results of scanning electron microscopy (SEM) showed that the fouling layer on the surface of the fouling film was the fouling layer with a reticular adhesion structure and the distribution of various microorganisms in the fouling layer. The short-term fouling of nanofiltration membrane is mainly granular macromolecular clusters, and there are adhesion structures after long-term filtration.
【学位授予单位】：沈阳师范大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：R123.1

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