【作者】 刘静；

【导师】 张晓健；

【作者基本信息】 清华大学 ， 土木工程， 2009， 博士

【摘要】 本论文研究的目的是完善短时游离氯后转氯胺的顺序氯化消毒工艺,在此基础上研究多点顺序氯化消毒工艺,探索有效控制微生物和消毒副产物的组合消毒工艺。通过实验室配置菌悬液进行顺序氯化消毒试验的结果表明:在微生物安全性方面,短时游离氯后转氯胺的顺序氯化消毒工艺对水中常见易灭活的大肠杆菌、较难灭活的金黄色葡萄球菌和铜绿假单胞菌都有协同灭活效果,对游离氯极难灭活的枯草芽孢没有协同灭活效果,这和以前的研究结果是不同的。在消毒副产物控制特性研究方面,研究结果表明顺序氯化消毒工艺在出厂和管网停留时间内,卤代消毒副产物的生成量都远低于游离氯消毒。研究结合水厂消毒剂投加经验和短时游离氯后转氯胺的顺序氯化消毒工艺提出了多点顺序氯化消毒工艺。对腐殖酸配水和实际原水进行消毒试验的结果表明,多点顺序氯化消毒工艺可以更加有效地保障饮用水微生物和消毒副产物安全。滤前滤后“两点加氯后转氯胺的顺序氯化消毒工艺”是多点顺序氯化消毒工艺在水厂的实际应用,该工艺在过滤工艺前投加一定量的游离氯,在清水池补投加氯后,立即进行加氨转化。研究通过中试确定了该工艺的使用参数,工艺满足微生物安全性控制、消毒副产物生成量控制和水处理工艺保障三重控制的效果,解决了传统预加氯消毒副产物生成量高,单点顺序氯化加氯点在过滤工艺后,无法保证过滤工艺稳定运行的问题。在国内水处理领域,首次采用荧光染色和流式细胞技术进行饮用水中的活菌计数和消毒灭活机理的研究。研究发现,该方法可以准确快捷地检测水中细菌的浓度。对消毒剂灭活机理的研究结果发现氯和氯胺灭活微生物的凋亡过程存在明显差异,游离氯消毒对细胞膜破坏迅速彻底,而氯胺对细胞的破坏是一个缓慢渐进过程。细胞灭活的不同阶段,包括活、死、早期凋亡和晚期凋亡可以通过流式细胞仪的凋亡分析精确区分。更多还原

【Abstract】 The object of this thesis research is to improve the short-term free chlorine plus chloramines disinfection process, based on this study multi-point sequential chlorination process is established and studied. A combined disinfection process, which is effective to control both microorganisms and disinfection by-product(DBPs), is explored by changing the chlorine and chloramines disinfectant dosing points, the dosage dose, time and other factors.It has been found that short-term chlorine disinfection and chloramines disinfection had synergetic effect on microorganism inactivation. This study focused on the difference of synergetic effect with different kinds of microorganism. The inactivation efficiency of sequential chlorination process on E.coli, S. aureus and P. aeruginosa was better than that of free chlorination or monochloramination of same available chlorine dosage individually, which means the existence of synergetic effect on these bacteria. However, this synergetic effect did not exist with the sequential chlorination on the spore of Bacillus subtilis. The investigation of DBPs at the effluent of water plant and the long residence time within the distribution system showed that sequential chlorination process generated far less halo-DBPs than free chlorine disinfection.The study of multi-point sequential chlorination process was based on sequential chlorination process and disinfectant dosage experiences of water plants. Experiments carried with both laboratory water and actual water showed that changing disinfectants dosing points and dosage dose could effectively reduce DBPs formation. At the same time, the advantages of sequential chlorination process on microorganisms and DBPs still worked well. These two aspects ensured the multi-point sequential chlorination process be a more safe disinfection.Two-points-short-term free chlorine plus chloramines disinfection process was used in conventional treatments of water supply as one of the multi-point sequential chlorination process. The process is adding chlorine at the start of filtration and clear well respectively and immediately adding ammonia to change the chlorine to chloramines in clear well. The point of chlorine dosing move up to the filtration process can decrease disinfection by-product yield and control bio-film growth in filtration process. HPC result also showed advantage in microorganism controlling.Fluorescence staining and flow cytometry (FCM) was first used in drinking water disinfection in this study. The cell concentration of microorganisms could be detected easily and accurately by fluorescence staining and FCM. Microorganism inactivation mechanism of chlorine and chloramines was found obviously different in apoptosis testing by FCM. Chlorine completely and rapidly destructed the cell membrane of bacteria, while chloramines’destruction was a slow and gradual process. Different periods of bacteria’s survivals, e.g. live, dead, early apoptosis and late apoptosis, could be detected.更多还原