典型水源水氯化消毒副产物的生成及其强化混凝特征
文献类型：学位论文
| 作者 | 赵艳梅 |
| 学位类别 | 博士 |
| 答辩日期 | 2013-05 |
| 授予单位 | 中国科学院研究生院 |
| 授予地点 | 北京 |
| 导师 | 汤鸿霄，王东升 |
| 关键词 | 溶解性有机物 化学分级 三卤甲烷 卤乙酸 强化混凝 Dissolved organic matter (DOM) Fractionation characterization THMs HAAs Enhanced coagulation |
| 其他题名 | Characteristics of disinfection by-product precursors of some typical source waters and their removal by enhanced coagulation |
| 学位专业 | 环境科学 |
| 中文摘要 | 饮用水源水中广泛存在的溶解性有机物（DOM）不但直接引起色度、嗅味等水质问题，而且可与消毒剂反应产生对人体不利的消毒副产物（DBPs）。以去除有机物为目的的强化混凝逐渐代替以去除浊度为目的的常规混凝，并成为控制DBPs 的最佳可行性技术之一。针对我国大多数水厂仍然使用常规混凝工艺的现状，进行我国饮用水源水DOM 的DBPs 生成特征及其强化混凝可去除性的研究具有重要现实意义。 本论文选取我国部分典型代表性水源（八个水源，三个季度），应用化学分级及紫外和荧光光谱分析方法，调查了DOM 的组成特征及其氯化消毒副产物生成势（DBPFP，包括四种三卤甲烷（THMs）和九种卤乙酸（HAAs））；根据亲疏水性不同较为系统地分析了DBPs 与DOM 之间的关系，并在此基础上研究了消毒副产物前驱物的强化混凝去除特征。得出了以下主要结论： （1）不同水源在DOM 含量、DBPFP 以及光谱特征上表现出一定的规律，同时也存在较大差异。多数水源卤乙酸的生成势大于三卤甲烷生成势 （HAAFP>THMFP），且春季高于冬季；而specific-THMFP 与specific-HAAFP则在冬春两季表现为相反的趋势。THMFP、HAAFP 分别与DOC、腐殖酸类、富里酸类荧光物质及ΔA272 之间存在线性相关性，说明荧光物质及有紫外吸收的DOM 具有较高的氯化活性；八个水源中，属于松辽流域的两个水源具有高紫外吸收、高腐殖酸类（HA）和富里酸类（FA）腐殖质含量、高DBPFP 的特征；属于珠江流域的水源除了以上特征外，还具有高蛋白类有机物含量的特征；除了属于黄河流域的一个水源因其溴离子含量高造成DBPFP 较大外，其他水源以上指标均具有相对较低的特征。憎水性物质（HoM）含有较多的羧酸类、酮类等具有不饱和键的有机物，紫外吸收高，荧光响应强，具有较高的THMFP；而亲水性物质（HiM）多含有氨基酸类等小分子且荧光强度比较弱的有机物，具有较高的HAAFP。HoM 更易生成氯代三卤甲烷和溴代卤乙酸，相反，HiM 则更易于生成溴代三卤甲烷和氯代卤乙酸。 （2）强化混凝虽然可以降低三卤甲烷和卤乙酸的生成势，但是不能改变我国卤乙酸生成势大于三卤甲烷生成势的水质特征。THMs 前驱物更易于强化混凝去除。部分水源混后水specific-THMFP 和specific-HAAFP 出现了升高现象，可能与混凝只是去除某一类有机物（如HoM 等）有关。传统混凝处理工艺对腐殖酸和富里酸类大分子有机物有较好的去除效果，而对蛋白类及代谢产物类去除效果不佳。滤后水HiM 及HA 含量均比沉后水高，则说明在处理过程中存在亲水性小分子物质释放或者大分子络合物生成的可能。 （3）HoM 较HiM 更易于混凝去除；混凝前后各化学分级组分对THMs 和 HAAs 的贡献发生了变化，尤其以HoN 的变化最明显。另外，混凝剂PACl 在去除亲水性物质时有一定的优势。 （4）保护较好的天然水体THMs 前驱物多于HAAs 前驱物，而人为污染水体HAAs 前驱物多于THMs 前驱物；以腐殖酸和富里酸类有机物为主、憎水性组分以及分子量高的组分含量高的源水，其强化混凝效果好于蛋白类有机物含量高、亲水性组分以及分子量低的组分含量高的源水；在无pH 调节条件下，传统混凝剂FeCl3 在较高投加量时对THMs 及HAAs 前驱物的去除效果好于Al2(SO4)3、PACl 和HPAC，而HPAC 在低投加量时具有一定优势；另外，HPAC在去除荧光类物质时表现出明显优势。 |
| 英文摘要 | Dissolved organic matter (DOM) is ubiquitous in drinking source waters. It not only can affect water quality by causing colour, taste and odor problems etc., but also can react with disinfects, leading to the formation of disinfection by-products (DBPs)which have potential adverse effects on human health. Enhance coagulation, aiming at maximized organic matter removal, gradually instead of conventional coagulation which is geared towards efficient removal of turbidity, to become one of the best available technologies to reduce DBP precursors. In China, majority water plants are still using conventional coagulation process. Therefore, it is of practical significance for studying the characteristics of disinfection by-product precursors of some typical source waters and their treatability by enhanced coagulation. In this study, the distribution and properties of DOM/DBPFP (four THMs and nine HAAs) in eight typical Chinese drinking source waters during different seasons and their treatability by enhanced coagulation were studied using chemical fractionation (RA) in conjunctin with UV spectroscopy and three dimensional excitation emission matrix fluorescence spectroscopy (3DEEM). The relationship between DBPs and DOM was analyzed. The main results were outlined as follows: (1) The risk of HAA formation was larger than that of THM formation (HAAFP>THMFP) in almost all source waters. The risk in spring was larger than that in winter. Compared with specific-THMFP, specific-HAAFP showed an opposite trend in different seasons: For MS, NB, NT and XS, specific-THMFP was higher in spring than that in winter, while specific-HAAFP was higher in winter than that in spring; For SC, BJ and XD, specific-THMFP was lower in spring than that in winter, while specific-HAAFP was lower in winter than that in spring. The good linear correlation between THMFP or HAAFP and DOC, HA, FA or ΔA272 indicated that DOM which contained fluorophore and UV chromophore having a higher chlorination activity. Eight source waters of East China had their own characteristics: both MS and SC, locating in the Songliao River Basin, hold high UV absorption, high humus content (HA and FA) and high DBPFP; In addition to the above features, XD, locating in the Pearl River Basin, also hold high protein-like organics content; DY, locating in the Yellow River Basin, hold high DBPFP because of its high concentration of bromide ions; Other source waters had relaviely low values in these features. The hydrophobic matter (HoM) contained more carboxylic acids and ketones with unsaturated bonds, more fluorophore and more UV chromophore, and had high THMFP. The hydrophilic matter (HiM) contained more low molecular organic matter with weak fluorescence response and had high HAAFP. HoM was more likely to generate chlorinated THMs and brominated HAAs, while HiM was more likely to generate brominated THMs and chlorinated HAAs. (2) Enhanced coagulation can reduce THM formation potential and HAA formation potential, but it can not change the water quality characteristics that HAA formation potential was higher than THM formation potential. THM precursors were more easily removed than HAA precursors by enhanced coagulation. The phenomenon that specific-THMFP and specific-HAAFP increased after coagulation for some source waters may be associated with coagulation mechanism that just certain organic matters were removed. The treatment process was more effective in removing humic and fulvic acids-like high molecular weight DOM than tryptophan-like material and low molecular weight DOM. The increasing of the content of HiM and HA in filtered water suggested that some hydrophilic low molecular weight DOM were released or some high molecular weight complex were formed in the treatment process. (3) HoM was more easily removed than HiM by enhanced coagulation. The THMFP and HAAFP of five fractions changed after coagulation. It was most obviously that the HAAFP of HoN increased after coagulation. (4) THM precursors were more than HAA precursors in a well-protected natural source waters while the reverse in an anthropogenic micro-polluted water. Natural organic matter (NOM) held better coagulation efficiency than synthetic organic contaminants (SOCs). NOM which mainly be the hydrophobic organic matter and high molecular weight DOM can be effectively destabilized by coagulation and then removed by sedimentation. HPAC had a little more efficient at low dosage while FeCl3 exhibited higher removal at high dosage. In addition, HPAC showed a clear advantage in removing fluorescence-like organics. |
| 公开日期 | 2014-10-28 |
| 源URL | [http://ir.rcees.ac.cn/handle/311016/7706]  |
| 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 | 赵艳梅. 典型水源水氯化消毒副产物的生成及其强化混凝特征[D]. 北京. 中国科学院研究生院. 2013. |
入库方式： OAI收割
来源：生态环境研究中心
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