金属离子对氯化消毒副产物生成的影响及机理研究

发布时间：2018-05-26 14:40

本文选题：金属离子 + 消毒副产物　；参考：《哈尔滨工业大学》2014年硕士论文

【摘要】：饮用水氯化消毒副产物的控制问题一直是水处理领域的研究热点之一。大量的实验证明，金属离子会在氯消毒剂与天然有机物(NOM)发生反应过程中起到一定的作用，从而影响DBPs的生成和分布规律，同时也会对消毒剂的消耗减少过程产生影响。在给水管网系统中，金属管道的腐蚀及金属管道管壁中的沉积物大量的向饮用水中溶解，这样会增加饮用水中常存在的Mg2+、Ca2+、Zn2+、Al3+、Fe2+、Mn2+等金属元素，其中，钙、镁元素含量在几十毫克/升的水平，而铁元素含量最高也可达十毫克/升，铝元素的含量也能达到较高水平。除此之外，由于工农业废水向水环境中排放，这样会使河底含有大量的金属化合物并且可以释放到水体内；不仅如此，而且水处理过程中大量使用含铝、含铁混凝剂，也会使处理的饮用水中的常存在金属离子含量增加，，这样会对最后消毒过程中消毒副产物的生成产生影响。所以，研究加入金属离子在氯化消毒过程中对消毒副产物生成规律的影响，将有利于了解金属离子在饮用水系统中的安全风险，对于保障饮用水安全和饮用水消毒副产物生成的控制都具有重要的意义。本文针对液氯消毒这一传统工艺,采用GC-EDC详细分析三氯甲烷(TCM)、三氯硝基甲烷（TCNM）、一溴二氯甲烷（BDCM）、一氯二溴甲烷（DBCM）、三溴甲烷（TBM）、二氯乙醛（DCA）、三氯乙醛（CH）、二氯乙腈（DCAN）、一溴一氯乙腈（BCAN）、二溴乙腈（DBAN）、三氯乙腈（TCAN）、二氯丙酮（DCP）、三氯丙酮（TCP）共13种挥发性消毒副产物，以及一氯乙酸（MCAA）、二氯乙酸（DCAA）、三氯乙酸（TCAA）、一溴乙酸（MBAA）、溴氯乙酸（BCAA）、二溴乙酸（DBAA）、一溴二氯乙酸（BDCAA）、一氯二溴乙酸（CDBAA）、三溴乙酸（TBAA）共9种非挥发性消毒副产物。通过对常价金属离子和变价金属离子的对比，以及对消毒副产物生成的影响机制研究，探讨金属离子在氯消毒过程中饮用水的安全性。本实验研究中主要选择水中常见的金属离子和价态具有特殊性质的金属离子，此次研究的金属离子包括：Mg2+、Ca2+、Zn2+、Ba2+、Al3+、Mn2+、Fe2+、Fe3+、Cu2+、Cu+等，这些金属离子对消毒副产物有一定的抑制或者促进的作用。通过筛选NOM作为氯化的对象，研究消毒副产物THMs和HAAs的变化，进行试验，后续得到数据，并对数据整理，分析氯化后各种消毒副产物的分布变化规律，并结合消毒副产物生成机制，对影响氯化消毒副产物生成的因素进行研究。通过对常价金属离子的研究，得出Mg2+、Ca2+对氯化消毒副产物的生成有一定的抑制作用。Ba2+和Zn2+对挥发性消毒副产物生成有一定的促进作用，而Al3+对挥发性消毒副产物基本没有影响，Ba2+、Zn2+、Al3+对非挥发性消毒副产物均有一定的促进作用。通过对变价金属离子的研究，得出变价金属离子对非挥发性的消毒副产物以及挥发性的消毒副产物均有一定的影响，其中Mn2+对三氯乙醛的影响最为大，只要有锰离子存在三氯乙醛的浓度就会从27μg/L增加为58μg/L，浓度变化为原来的2倍。而Cu2+对挥发性消毒副产物的促进作用最大，随着Cu2+浓度的增加，TCM和CH的浓度分别由150μg/L和27μg/L变为255μg/L和120μg/L。当有Mn2+和Cu2+存在时，随着pH的增高，消毒副产物的含量不断的减少，原因可能是由于脱卤的作用。而两者产生的氧化体系，在30min之内，不能对对氯苯甲酸（pCBA）和苯甲酸（BA）降解，由此可以得出其中起作用的可能是金属离子的不同价态以及不同的形态如氧化物形态。而金属离子与氯形成的氧化体系中，锰离子与氯形成的氧化体系对含藻水预氧化后，进行氯化实验生成的氯化消毒副产物的含量最低。
[Abstract]:The control of chlorinated disinfection by-products in drinking water has been one of the hot topics in the field of water treatment. A large number of experiments have proved that metal ions play a role in the reaction process of chlorine disinfectant and natural organic matter (NOM), thus affecting the generation and distribution of DBPs and the reduction of the consumption of disinfectants. In the water supply network system, corrosion of metal pipes and a large amount of sediment in the pipe wall of metal pipes dissolve in drinking water. This will increase the metal elements such as Mg2+, Ca2+, Zn2+, Al3+, Fe2+, Mn2+, which often exist in drinking water, of which the content of calcium and magnesium is at the level of tens milligram / liter, and the highest content of iron can be up to ten In addition to the discharge of industrial and agricultural wastewater into the water environment, it will make the bottom of the river contain a large amount of metal compounds and can be released into the water body. Not only that, but also the use of aluminum and iron coagulants in the process of water treatment also makes the treatment of drinking water regular. There is an increase in the content of metal ions, which will affect the production of disinfection by-products during the final disinfection process. Therefore, it will be beneficial to understand the safety risk of metal ions in the drinking water system and to ensure the safety and drinking of drinking water in the process of chlorination. The control of water disinfection by-products is of great significance.
Aiming at the traditional process of liquid chlorine disinfection, this paper uses GC-EDC to analyze the trichloromethane (TCM), three chloro nitromethane (TCNM), mono bromo dichloromethane (BDCM), dichloromethane (DBCM), three bromo methane (TBM), two chloral acetaldehyde (DCA), three chloral acetaldehyde (CH), two chloro acetonitrile (DCAN), mono bromination acetonitrile (BCAN), dichbrocyanonitrile (DBAN), three chloronitrile (TCAN), two). Chloroacetone (DCP), three Chloroacetone (TCP), 13 kinds of volatile disinfection by-products, as well as two chloroacetic acid (MCAA), two chloroacetic acid (DCAA), three chloroacetic acid (MBAA), bromo chloroacetic acid (BCAA), mono bromoacetic acid (DBAA), mono bromo two chloroacetic acid (BDCAA), monchloroacetic acid (CDBAA), three bromoacetic acid (TBAA), a total of 9 non volatile disinfection by-products. The comparison of the normal metal ions with the variable valence metal ions and the mechanism of the effect on the formation of the disinfection by-products are studied, and the safety of the drinking water in the process of chlorine disinfection is discussed.
In this study, metal ions and metal ions with special properties are selected mainly in the water. The metal ions of this study include: Mg2+, Ca2+, Zn2+, Ba2+, Al3+, Mn2+, Fe2+, Fe3+, Cu2+, Cu+, etc. these metal ions have a certain inhibition or promotion effect on the disinfection by-products. The changes in the disinfection by-products THMs and HAAs were studied, the data were carried out and the data were obtained. The distribution and variation of various disinfection by-products after chlorination were analyzed, and the formation mechanism of disinfection by-products was combined to study the factors affecting the formation of chlorinated disinfection by-products.
Through the study of the normal metal ions, it is concluded that Mg2+ and Ca2+ have certain inhibitory effects on the production of chlorination by-products,.Ba2+ and Zn2+ have certain promoting effect on the generation of volatile disinfection by-products, while Al3+ has no effect on the volatile disinfection by-products. Ba2+, Zn2+, and Al3+ have a certain promotion on non volatile disinfection by-products. Effect.
Through the study of the valence metal ions, it is concluded that the variable valence metal ions have a certain influence on the non volatile disinfection by-products and the volatile disinfection by-products, in which Mn2+ has the greatest influence on the three chloral aldehyde, as long as the concentration of three chloral aldehyde with manganese ions will increase from 27 to 58 mu g/L, and the concentration change is 2 times that of the original. And Cu2+ had the greatest promotion effect on the volatile disinfection by-products. With the increase of Cu2+ concentration, the concentration of TCM and CH changed from 150 to 255 to 255 mu g/L and 120 mu g/L., respectively.
When Mn2+ and Cu2+ exist, the content of disinfection by-products decreases with the increase of pH, which may be due to dehalogeny, and the oxidation system produced by both can not degrade chlorobenzoic acid (pCBA) and benzoic acid (BA) within 30min, which may result in the possible different valence states of metal ions. In the oxidation system formed by metal ions and chlorine, the content of chlorinated disinfection by-products produced by chlorination experiments is the lowest in the oxidation system formed by manganese ions and chlorine.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU991.25

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