供水管网中氯胺作用下内分泌干扰物的迁移转化机理研究

发布时间：2018-01-01 08:43

本文关键词：供水管网中氯胺作用下内分泌干扰物的迁移转化机理研究　出处：《浙江大学》2017年博士论文　论文类型：学位论文

【摘要】：近年来,伴随着工业的迅速发展和人民生活水平的提高,水环境的污染问题也日益突出,人们对饮用水安全的关注也越来越多。同时,检测技术的进步,使得水体中越来越多的内分泌干扰物(EDCs)被检测出来,研究证明EDCs会对水体中的生物产生雌激素效应。此外,氯胺消毒是通常采用的一种饮用水消毒方式,但是对于氯胺作用下EDCs在城市供水过程中的迁移转化机理的研究尚未见报道。本文以长期存在于水体中的雌二醇(E2)、雌三醇(E3)和双酚A(BPA)为研究对象,利用浙江大学玉泉校区中试管网实验平台为研究手段,系统研究了氯胺作用下三种EDCs在城市供水管网中的降解影响因素,产物生成情况以及降解过程中水体生物毒性的变化情况。为了确定后续EDCs降解所采用的氯氮比(Cl/N)以及氯胺浓度,本研究首先考察了不加EDCs的情况下,氯胺的生成和衰减情况。对不同Cl/N下氯胺的生成情况进行研究发现:Cl/N介于1-14之间时,自由氯、一氯胺和总有效氯在不同水质条件下的生成趋势均为去离子水主体水中试管网;而对于二氯胺,在中试管网中的生成量远高于去离子水中的生成量,且在Cl/N为10时,中试管网中二氯胺浓度占总有效氯浓度的90%以上。对不同Cl/N下氯胺的衰减情况进行研究发现,球墨铸铁管中各种形态的氯胺在不同Cl/N下的衰减趋势相同,一氯胺在不同Cl/N下的衰减速率为6:13:14:15:1,随着反应的进行,二氯胺浓度先增大后减小,且这种变化与Cl/N没有明显的相关性;此外,一氯胺在不同管材中的衰减速率为不锈钢管PE管球墨铸铁管,二氯胺的浓度在不同管材中均先增大后减小,且增大趋势为不锈钢管PE管球墨铸铁管。通过对EDCs在去离子水和中试管网中的降解规律的研究发现,不同Cl/N下,EDCs在去离子水和中试管网中降解区别较大,具体表现为在Cl/N为3和4时,反应9h,EDCs在去离子水中的去除率小于30%,而在管网中,EDCs的去除率在70%以上,这主要是由于不同水体条件下,反应体系中NH2Cl和NHCl2所占的比例不同造成的。此外,增加初始总有效氯的浓度、升高温度、提高反应体系的pH和增加管网中水流流速均可加快EDCs的降解。但是,当反应体系中溴离子浓度介于0-80μg/L时,溴离子浓度的变化对EDCs的降解几乎没有影响。不同管材下,EDCs的降解速率为球墨铸铁管PE管不锈钢管,这是管垢,水体pH、氯胺含量共同作用的结果。对不同水质条件下EDCs的降解发现,主体水有机物和管壁本身并不影响EDCs的降解,在加氯胺的情况下,才会对EDCs的降解产生影响,且影响均是负面的,即主体水有机物和管壁的存在均不利于EDCs的降解。此外,利用GC-MS首次对氯胺消毒下EDCs降解的中间产物进行了检测。其中,E2的检测中共检测到10种中间产物,且第一次检测到E2的含氮副产物。分析发现氯胺消毒情况下,E2的反应发生在苯环、C9和C17上,主要为苯环酚羟基临位的取代反应、消去反应和加氢反应。E3的检测中共检测到9种中间产物,其中E2和2-氯-E3是两种主要的中间产物,说明亲电取代反应是E3氯胺消毒过程中的主要反应。BPA的检测中共检测到12种中间产物,且第一次检测到BPA的含氮副产物,在氯胺作用下,BPA的反应主要为苯环酚羟基临位的亲电取代反应,包括氯取代、溴取代以及N02的取代。三种EDCs的降解中均没有检测到开环的产物。对EDCs在氯胺作用下的生物毒性检测发现:随着反应时间的增加,反应体系的雌激素活性先升高后降低,最后趋于稳定。降解反应的前期,水体的雌激素活性大于同时刻空白对照实验的雌激素活性,说明EDCs浓度的下降可能并不意味着其雌激素活性的下降,中间产物的雌激素活性可能强于母体分子的雌激素活性。因此,对EDCs降解过程中雌激素活性的评估,应该明确消毒时间,并且在去除污染物的同时,也要采取必要措施减少消毒工过程中中间产物的生成。
[Abstract]:In recent years, with the rapid development of industry and the improvement of people's living standard, the problem of water pollution has become increasingly prominent, people pay attention to the safety of drinking water is also increasing. At the same time, detection technology, making more and more water in the endocrine disruptors (EDCs) were detected, studies have shown that EDCs can produce estrogen effect of water organisms. In addition, Chloraminated drinking water disinfection is a commonly used method, but for the study of migration and transformation mechanism in city water supply in the process of chloramine EDCs under the action has not been reported. In this paper, persist in the water in the estradiol (E2), female three alcohol (E3) and bisphenol A (BPA) as the research object, using the experimental platform of Zhejiang University campus network Jade Spring tube as the research means, research the influence factors of the degradation system under three kinds of chloramine EDCs role in city water supply network, product formation The changes of water and biological toxicity of the degradation process. In order to determine the chlorine nitrogen ratio with subsequent degradation of EDCs (Cl/N) and chloramine concentration, this study first investigated the absence of EDCs, chloramine generation and attenuation of Cl/N under different conditions to generate chloramine Cl/N between the study found: 1-14, free chlorine, monochloramine and production trends of the total active chlorine in different water conditions were deionized water body water tube net; and for the two generation of chloramine, generation in tube network is much higher than that of deionized water, and when the Cl/N is 10, in the tube network two chloramine the concentration of effective chlorine concentration accounted for more than 90%. The study found that the attenuation of different Cl/N chloramine, the attenuation trend of nodular cast iron pipe chloramine in various forms in different Cl/N under the same, the decay rate of monochloramine under different Cl/N 6:13:14:15:1, as the reaction proceeds, two chloramine concentration increased first and then decreased, and the change of Cl/N with no obvious correlation; in addition, the decay rate of monochloramine in different pipe cast iron pipe for stainless steel pipe ductile, the concentration of two chloramine increased firstly in different pipe and then decreased, and increased trend stainless steel pipe ductile iron pipe. Through the research on the degradation of EDCs in deionized water and in vitro in the network found that under different Cl/N, EDCs in deionized water and in vitro degradation in the net difference is bigger, the specific performance in Cl/N was 3 and 4, the reaction of 9h, the removal rate of EDCs in deionized water less than 30%, while in the network, the EDCs removal rate is over 70%, which is mainly due to the different water conditions in the reaction system of NH2Cl and NHCl2 in the proportion of different causes. In addition, increase the concentration of effective chlorine, total initial temperature, extraction The high pH of the reaction system and increase the network flow velocity could accelerate the degradation of EDCs. However, when the concentration of bromide ion in the reaction system between 0-80 g/L, bromide concentration degradation of EDCs has almost no effect. Different pipes, the degradation rate of EDCs for ductile iron PE tube stainless steel tube, the is the pipe scale, water pH, interaction results. The degradation of chloramine content under different water quality EDCs, the main water organic matter and the wall itself does not affect the degradation of EDCs, in the case of the influence of chloramine, the degradation of EDCs and will influence is negative, which is the main water the organic matter and the pipe wall are not conducive to the degradation of EDCs. In addition, the use of GC-MS for the first time on EDCs degradation of chloramine disinfection under the intermediate products were detected. The detection of E2 were detected in 10 kinds of intermediate products, and the first detected nitrogen by-products containing E2 Analysis shows that chloramine disinfection conditions, E2 reaction occurs in the benzene ring, C9 and C17, mainly for the benzene hydroxyl substitution reaction on the elimination reaction and hydrogenation reaction of.E3 detection were 9 kinds of intermediate products, including E2 and 2- chloride -E3 are two main intermediate products, to illustrate the pro the electrical substitution reaction is the main reaction.BPA E3 chloramine disinfection in the process of detection were 12 kinds of intermediate products, and the first detected nitrogen byproducts containing BPA, chloramine in under the action of the BPA reaction was benzene phenol hydroxyl adjacent electrophilic substitution reaction, including chlorine, bromine and N02 replace. Degradation of three EDCs in the products were not detected. The open loop found on the ecotoxicity of EDCs in chloramine under the action: with the increase of reaction time, the reaction system of the estrogenic activity increased first and then decreased, and finally tends to be stable. The degradation reaction, Estrogenic activity of water is greater than the time control estrogen activity experiment, that the decline in the concentration of EDCs may not mean the decline of estrogen activity, the estrogenic activity of estrogenic activity of intermediates may be stronger than the parent molecule. Therefore, the evaluation of the estrogenic activity of EDCs in the degradation process, should clear the disinfection time, and in the removal of pollutants at the same time, to take the necessary measures to reduce the formation of intermediate products in the process of disinfection work.

【学位授予单位】：浙江大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：TU991.33

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