【作者】 岳尚超；

【导师】 王启山；

【作者基本信息】 南开大学 ， 环境工程， 2012， 博士

【摘要】 预氯化工艺由于能够有效杀灭细菌等病原微生物，且具有成本低廉等优势，在世界范围内的给水厂中应用最为广泛。但是在预氯化过程中，水源水中普遍存在的天然有机物（NOM）与氯作用生成较高浓度的DBPs，而三卤甲烷（THMs）和卤乙酸（HAAs）等代表性DBPs已被证实为致癌物质。因此，人们开始寻求新的预氧化技术来代替预氯化，从而降低出水中DBPs含量，保障饮用水的安全性。预臭氧化技术是当前研究较多的一种预氧化技术。本文以天津市水源水为研究对象，进行小试试验研究预臭氧化工艺对微污染原水消毒副产物含量的影响因素；在不同水质期和不同水源水条件下进行生产性试验，研究预臭氧化工艺对消毒副产物的影响以及对水质净化的作用，并比较了预臭氧化工艺和传统预氯化工艺对不同水质期原水的处理效果。对于预臭氧化技术的研究符合我国水处理的发展方向，对于预臭氧化在我国的应用有重要的实际意义和应用价值。预臭氧化工艺小试试验研究发现：增加臭氧投加量，能够持续降低水体中三卤甲烷生成势（THMFP）和卤乙酸生成势（HAAFP）。但是，臭氧投加量的增加将提高溴酸盐的生成量；在较短的反应时间内，THMFP和HAAFP含量均出现小幅度增加，而随着反应时间延长，THMFP和HAAFP含量下降。同时，在较短的反应时间时，溴酸盐生成量变化幅度较大；当水体偏酸性时，随着pH值增加，水体中的THMFP和HAAFP含量增加；而当水体偏碱性时，随着pH值增大，THMFP和HAAFP含量逐渐降低。在碱性条件下，溴酸盐含量升高趋势较明显。高温高藻期内，预臭氧化生产性试验研究得到以下结论：预臭氧化对滦河水中藻类、叶绿素a、UV₂₅₄和SUVA的去除率分别为45.76%、44%、38.21%和32.07%。臭氧能够氧化分解大分子有机物生成3kDa-10kDa，1kDa-3kDa分子量区间的小分子有机物。预臭氧化单元THMFP和HAAFP的去除率分别为12.43%和15.06%；臭氧对THMFP的去除主要体现在对三氯甲烷和一溴二氯甲烷前体物的去除；臭氧对HAAFP的去除主要体现在对一氯乙酸（MCAA）、二氯乙酸（DCAA）和三氯乙酸（TCAA）的去除。滦河水经预臭氧化作用后，溴酸盐生成量较小，低于6μg/L。而预臭氧化后，甲醛含量有不同程度的增加，但是后续处理工艺对甲醛处理效果显著，出厂水中甲醛含量平均为33.7μg/L。预臭氧化后续处理单元能够进一步净化水质，整套处理工艺对于高温高藻水的处理效果能够达到国家相关标准。低温低浊期期内，预臭氧化生产性试验研究得到以下结论：预臭氧化对藻类、叶绿素a、UV₂₅₄和SUVA的去除率平均为34.45%、34.35%、38.21%和32.07%。预臭氧化对THMFP和HAAFP的去除率分别为30.95%和33.61%；臭氧对THMFP的去除主要体现在对三氯甲烷和一溴二氯甲烷前体物的去除；臭氧对HAAFP的去除主要体现在对DCAA和TCAA的去除。溴酸盐未检出。预臭氧化后甲醛含量有不同程度的增加，但是后续处理工艺对甲醛处理效果显著降低，出厂水中甲醛含量平均为70.12μg/L。后续处理单元进一步净化水质。整套处理工艺对于不同来源水源水具有一定的适应性，对低温低浊水的处理效果能够达到国家相关标准。通过比较研究生产性试验中预臭氧化和预氯化两种预氧化技术对天津市不同水质期水源水的处理效果发现：预臭氧化的优势主要体现在其对藻类、菌落总数、UV₂₅₄、SUVA、THMFP和HAAFP较强的去除效果。预臭氧化工艺能够有效改善出水水质，所需混凝剂和需氯量较低，能够降低氯消毒副产物前体物，且能够有效控制臭氧消毒副产物的生成。综合以上各生产性试验结果，可以看出，与传统预氯化工艺的对比，预臭氧化更有利于去除藻类、菌落总数、UV₂₅₄、SUVA、THMFP和HAAFP等污染物。整套处理工艺对天津市不同水质期以及不同来源水源水具有较强的适应性，出水水质达标，并能够降低出水中DBPs含量，同时臭氧消毒副产物得到有效控制。预臭氧化工艺处理天津市水源水是可行的，并且可以取得较好的处理效果。更多还原

【Abstract】 The pre-chlorination process can effectively control pathogenicmicroorganisms and the cost was very low. Therefore, the pre-chlorination processwas widely used in water supply plants in the world. However, during thepre-chloriantion process, the natural organic matter（NOM） in raw water reacted withchlorine to form disinfection by-products（DBPs）, of which trihalomethane（THMs）and haloacetic acids（HAAs） were considered carcinogenic. Therefore, newtechnology of pre-oxidation is required, to decrease DBPs and to keep the dringkingwater safe. Pre-ozonation process is a promising pre-oxidation process that are beingstudied.The source water in Tianjin was used in the lab-scale study. The effect ofpre-ozonation on DBPs was studied by changing the operational parameter; afull-scale study was also placed in a water supply plant in Tianjin. It was carried outduring different water quality periods and with different source waters. Theperformance of pre-ozonation on raw water was studied, and the effect ofpre-ozonation on DBPs was expecially estimated. The different effects between thepre-chlorination and pre-ozonation were investigated. It is significative to study theapplication of pre-ozonation in full-scale plant.The lab-scale research on pre-ozonation showed that the formation potential oftrihalomethanes （THMFP） and haloacetic acids（HAAFP） decreased by increasingthe ozone dosage, but the high concentration of ozone might lead to the formation ofbromate. When the reactiion time was low, THMFP and HAAFP increased by a lowlevel, while by extending the reaction time, THMFP and HAAFP were reduced.With a low reaction time, bromate was formed rapidly. When the raw water wasacidic, the concentration of THMFP and HAAFP got larger by increasing pH; whenalkaline, the result was opposite. There was a great formation of bromate when thewater was alkaline.As to the Luan River water in summer with high amounts of algae, the full-scale study showed that the removal rates of pre-ozonation on algae,Chlorophyll a, UV₂₅₄and SUVA were45.76%,44%,38.21%and32.07%,respectively. Ozone decomposed the high molecular weight（MW） organic mattersinto lower MW ones, such as organic matters with MW between3kDa and10kDaor between1kDa and3kDa. After pre-ozonation, about12.43%of THMFP and15.06%of HAAFP were reduced. The removal of THMFP was attributable to thereduction of the formation potential of Chloroform and Bromodichloromethane;while the removal of MCAA, DCAA and TCAA contributed to the decrease ofHAAFP. The concentration of bromate was below6μg/L. Formaldehyde wasformed to some extent, and then removed effectively by the follow-up processes. Inthe final effluent, the concentration of formaldehyde was33.7μg/L. The otherprocesses following pre-ozonation gave a further treatment and the final effluentshowed a good water quality, which suggested an excellent treatment of the waterwith high alage.With regard to water in winter with low temperature and low turbidity, thefull-scale study showed that the removal rates of pre-ozonation on algae,Chlorophyll a, UV₂₅₄and SUVA were34.45%,34.35%,38.21%and32.07%,respectively. After pre-ozonation, about30.95%of THMFP and33.61%of HAAFPwere reduced. The removal of THMFP was attributable to the reduction of theformation potential of Chloroform and Bromodichloromethane; while the removalof DCAA and TCAA contributed to the decrease of HAAFP. No bromate wasdetected from the effluent after pre-ozonation. Formaldehyde was formed to someextent, and then removed effectively by the follow-up processes, in the final effluent,the concentration was70.12μg/L. The other processes following pre-ozonation gavea further treatment, and the final effluent showed a good water quality, whichsuggested an excellent treatment of the water with low temperature and low turbidity.The performance of the processes also showed an excellent ability to treat differentsource waters.Comparing the effects of the two different pre-oxidation processes,pre-chlorination and pre-ozonation, to treat raw waters in different water qualityperiods, it showed the same results that pre-ozonation had a better effects to treat alage, colony, UV₂₅₄, SUVA, THMFP and HAAFP. The treatment processes withpre-ozonation produced drinking water with better water quality. The pre-ozonationprocess may reduce the demand of coagulating agent and chlorine, remove theDBPFP and control the formation of by-products of ozonation.In conclusion, pre-ozonation had a better effects to treat alage, colony, UV₂₅₄,SUVA, THMFP and HAAFP, compared to pre-chlorination. The processes appliedin the water supply plant with pre-ozonation had a good ability to treat raw waters indifferent water quality periods or from different water sources. The water quality offinal effluent met the drinking water standards. The DBPFP was reduced and theformation of by-products of ozonation was controlled effectively. The processeswith pre-ozonation had an excellent effect to treat the source waters in Tianjin.更多还原