【作者】 孙文俊；

【导师】 祝万鹏； 刘文君；

【作者基本信息】 清华大学 ， 环境科学与工程， 2010， 博士

【摘要】 本文通过实验室配水试验、中试试验及实际工程,系统研究了针对我国饮用水水源水质的紫外线消毒生物安全性和系统可靠性;提出紫外线消毒后管网水质微生物稳定性特征,揭示紫外线及辅助消毒剂剂量、管网水力学及水质条件与微生物生长速率的定量关系;根据生物安全性的研究结果确定紫外线反应器的设计原则和方法;构建饮用水紫外线消毒综合设计框架。研究结果表明:紫外线消毒对大肠杆菌、细菌总数和管网中分离的抗氯菌Sphingomonas TS001灭活效果显著;枯草芽孢杆菌和MS2噬菌体对紫外线有一定的抗性,在0~80mJ/cm~2的剂量范围内,紫外线剂量与其灭活率呈较好的线性关系;紫外线对藻的灭活效果根据藻种不同有较大的差异;颗粒物对紫外线消毒的影响可以用基于游离细菌和结合细菌的二重动力学方程描述。紫外线消毒在正常剂量下不会影响水体中的AOC浓度,不改变水体的耗氯量,不影响总三卤甲烷和总卤乙酸的生成特性,也不会增加水体的遗传毒性风险。紫外线消毒管网生物安全性与AOC直接相关,当管网水AOC<15μg/L时,单独紫外线消毒可以维持管网的生物安全性,当管网的AOC=100~200μg/L时,管网余氯需要控制在0.5mg/L以上;对于本研究采用的中试试验的模拟管网系统,紫外线单独消毒不能够满足其生物安全性要求;对于供水管线较短且管网状况良好的小型管网,单独紫外线消毒基本上可以保证其生物安全性;根据消毒方式和管材的不同,管网微生物群落结构表现出较大的差异,紫外线联合氯或氯胺消毒可以有效控制管网微生物种类;紫外线与氯联合消毒对模拟管网生物膜的控制具有协同作用。微生物在紫外线反应器中的平均灭活率取决于微生物经过紫外线反应器的路径和其对紫外线的敏感度。紫外线联合氯胺的多级屏障消毒模式是保障生物安全性和副产物安全性的合理方法。紫外线消毒综合设计框架方法可以为紫外线技术在饮用水处理中的应用提供一定的技术参考。更多还原

【Abstract】 Biological safety and system stability of UV disinfection according to the drinking water quality in China was studied in this paper, based on lab-, pilot- and field experiments. Microbial stability characteristic in water distribution system after UV disinfection was presented, revealing the quantitative relation among UV and assistant disinfectant, hydraulics and water quality, microbe growth rate; establishing the design principles and methods of UV reactor derived from the results on microbial safety, constructing the control theory of biological safety and technical index system as well as integrated design framework, providing theoretical and technical support for safe drinking water disinfection along with transporting through the water distribution system.The results showed that UV is effective for E. coli, total bacteria counts, and Sphingomonas TS001 which is chorine resistant and separated from model distribution systems. Bacillus subttilis and MS2 phage are not very UV sensitive. When UV dose is 0~80mJ/cm~2, the UV dose and the inactivation rate have a good linear relationship. While, the inactivation effect on algae is not so good, with the significant difference in different species. Impact of UV on particles could be described by two-kinetic model based on the free and partical-associated microbe.UV does not impact the AOC with the normal doses. And UV does not change the chlorine demand of water and the formation characteristic of THMs and HAAs. Also, UV could not increase the genotoxicity risk in the water.The biological safety of distribution system following UV is direct related to AOC. When the AOC below 15μg/L, UV solely could keep the biological safety of distribution systems; when AOC=100~200μg/L, it need the chlorine residual of at least 0.5mg/L. UV disinfection solely could not keep the biological safety in the model distribution systems of pilot scale in this study. For the small and perfectly sealed distribution system, UV disinfection solely can keep the biological safety. The biofilm community depends on the disinfection manners and pipe materials. UV combined with chlorine or chloramine can decrease the species of microbe in the distribution systems. UV combined with chlorine disinfection has the synergistic effect for controlling the biofilm in the model distribution systems.The average inactivation rate of micro-organism in the UV reactor depends on the path and sensitivity of the micro-organism. The multi-barriers model of UV combined chloramine is the reasonable manner for controlling the biological and DBPs safety. The integrated design framework of UV disinfection can provide a certain technical reference for the application of UV on the drinking water treatment.更多还原