再生水体中环境雌激素的转化机理和影响因素

发布时间：2018-06-21 20:05

本文选题：光降解 + 氨氮　；参考：《北京化工大学》2015年硕士论文

【摘要】：近年来,水体中环境雌激素污染严重,再生水体中低痕量的环境雌激素具有很强的雌激素效应,市民的健康受到威胁,然而目前关于环境雌激素在水体中的迁移转化研究尚不全面,已有研究主要报道的是在紫外光照下高浓度雌激素的光降解行为,而实际污染的再生水体中雌激素含量在纳克级。本课题在前期对再生水体中雌激素分布调查研究的基础上,选取了雌酮为研究对象,采用氙灯模拟太阳光研究水体中雌激素E1光化学转化的影响因素,并探讨再生水体中E1的转化机理。首先,研究了纯水体系中无机离子对雌激素E1光降解的影响。(1)以氙灯为光源的光降解体系中对环境雌激素E1的降解速率较快,光照20 min后雌激素E1降解率为87%。(2)研究了不同的无机离子对雌激素E1的影响,如NH4+, N03等,结果表明：NH4-N会抑制雌激素E1的光降解行为,使雌激素El的降解率下降,且水相中随着NH4-N浓度的增加,雌激素El的降解率降低,雌激素E1的光降解反应速率减小,从而在水相中的半衰期增大。(3)NO3-N可以促进水相中雌激素E1的光降解行为,水相中加入一定量NO3-N,E1的降解率相应增加,同时El的光降解反应速率增大。(4)NH4-N和NO3-N共存的雌激素水相中,NO3-N对雌激素E1的光降解的促进起主导作用,促进其雌激素E1的降解,且随着水相中NO3-N和NH4-N浓度比增加,E1降解率增加,E1的光降解反应速率增大,即E1在水相中的半衰期缩短。其次,研究了高碑店湖表层水基质条件下雌激素El的光降解行为。模拟了太阳光光照高碑店湖表层水基质下雌激素E1的实验,随着湖水水流方向NH4-N的浓度逐渐增加,雌激素El的光降解反应速率逐渐减小,因此NH4-N是影响高碑店湖水体中雌激素El降解的重要因素之一最后,为了探讨雌激素El在水体中的转化机理,通过红外光谱仪、电子自旋共振波谱仪、气相色谱质谱联用仪等方法对雌激素El光降解过程及产物进行了研究,同时,研究光降解过程中El水溶液的内分泌干扰活性变化。(1)通过红外光谱研究雌激素E1的降解过程发现：光降解过程中E1的苯环遭到破坏,1720 cm-1对应的C=O键特征峰在光照时间为0、10和20 min样品中的强度逐渐减弱,而2854 cm-1和2925 cm-1对应的脂肪碳的C-H键特征峰先增强后减弱,可能是因为E1结构中的C-C=O发生了反应生成了C=C-OH,而随着反应的继续,C=C也被进一步氧化。(2)通过电子自旋共振波谱研究雌激素El的降解过程发现：模拟太阳光光照雌激素E1水系反应中可能产生了羟基自由基(·OH),其可能的途径为光照雌激素El产生水合电子(eaq-)。发生一系列反应产生了氧化物质如(·OH),进而这些氧化物质同雌激素El反应使其降解。(3)通过气相色谱质谱研究雌激素E1的降解过程发现：光降解雌激素E1水系过程中,雌激素E1得到明显的降低,同时对雌激素E1衍生化产物的图谱与标准图谱比对研究,结果表明雌激素E1在光降解中产生了中间产物。同时也可以看出降解过程中的酮基发生改变生成了碳碳双键,以及苯环遭到破坏。(4)通过对光降解过程中的E1的雌激素效应研究发现：其一,随着光照时间的增加,四种水相中的雌激素E1毒性有显著的降低,光降解过程中没有产生比E1毒性更强的雌激素化合物；其二,NH4-N对光降解中雌激素E1毒性影响不大；其三,光降解过程中NO3-N的存在使水溶液的内分泌干扰活性降低的更快,最终可能使其雌激素矿化为二氧化碳和水。
[Abstract]:In recent years, environmental estrogens are polluted seriously in the water body. The low trace environmental estrogens in the regenerated water body have a strong estrogen effect, and the health of the citizens is threatened. However, the study on the migration and transformation of environmental estrogens in water bodies is not comprehensive. The main report is that the high concentration of estrogen is light under ultraviolet light. On the basis of the investigation of estrogen distribution in the regenerated water body, the estrone is selected as the research object and the influence factors of the photochemical transformation of estrogen E1 in the water body are studied by using xenon lamp to simulate the photochemical transformation of estrogen in the water body, and the transfer of E1 in the regenerated water body is discussed. First, the effect of inorganic ions on the photodegradation of estrogen E1 in pure water system was studied. (1) the degradation rate of environmental estrogen E1 was faster in the photodegradation system with xenon lamp as the light source. The degradation rate of estrogen E1 after 20 min was 87%. (2), and the effects of different inorganic ions on estrogen E1 were studied, such as NH4+, N03 and so on. NH4-N can inhibit the photodegradation behavior of estrogen E1 and decrease the degradation rate of estrogen El, and with the increase of NH4-N concentration, the degradation rate of estrogen El decreases, the rate of the photodegradation reaction of estrogen E1 decreases, and the half-life in the water phase increases. (3) NO3-N can promote the photodegradation behavior of estrogen E1 in the water phase, and the water phase is added to the water phase. In a certain amount of NO3-N, the degradation rate of E1 increased correspondingly and the photodegradation rate of El increased. (4) in the estrogenic water phase of NH4-N and NO3-N, NO3-N played a leading role in promoting the photodegradation of estrogen E1, promoting the degradation of estrogen E1, and the E1 degradation rate increased with the increase of NO3-N and NH4-N concentration in the water phase and the photodegradation reaction of E1. The rate of the half-life of E1 in the water phase is shortened. Secondly, the photodegradation behavior of estrogen El under the surface water matrix of Gaobeidian lake is studied. The experiment of estrogen E1 under the surface water matrix of Gaobeidian lake is simulated by the sun light light. With the concentration of NH4-N in the water direction of lake water increasing gradually, the rate of photodegradation reaction of estrogen El is gradual. As a result, NH4-N is one of the important factors affecting the degradation of estrogen El in the water of Gaobeidian lake. In order to explore the transformation mechanism of estrogen El in water body, the photodegradation process and products of estrogen El are studied by infrared spectrometer, electron spin resonance spectroscopy, gas chromatography-mass spectrometry and so on. Changes in the endocrine disrupting activity of El aqueous solution during photodegradation (1) the degradation process of estrogen E1 was studied by infrared spectroscopy. It was found that the benzene ring of E1 was destroyed during the photodegradation, and the characteristic peaks of the C=O key corresponding to the 1720 cm-1 were gradually weakened in the light time of 0,10 and 20 min samples, and the 2854 cm-1 and 2925 cm-1 corresponding fats. The characteristic peak of carbon C-H bond first increased and then weakened, probably because of the reaction of C-C=O in the E1 structure to generate C=C-OH, and with the continuation of the reaction, C=C was further oxidized. (2) the degradation process of estrogen El was studied by the electron spin resonance spectroscopy, and it was found that the simulated sun light illuminated the estrogen E1 water system and the hydroxyl group may produce hydroxyl group. The free radical (OH), its possible pathway is the production of hydrous electrons (eaq-) in the light of estrogen El. A series of reactions produce oxidizing substances such as (. OH), and then these oxidizing substances degrade with estrogen El. (3) the degradation process of estrogen E1 was studied by gas chromatography mass spectrometry. E1 was significantly reduced. At the same time, compared with the standard atlas of the estrogen E1 derivatives, the results showed that the estrogen E1 produced intermediate products in the photodegradation. At the same time, it can be seen that the change of the ketone in the degradation process generated carbon carbon double bonds and the benzene ring was destroyed. (4) through the E1 degradation process, the E1 The study of estrogen effect found that: first, with the increase of light time, the toxicity of estrogen E1 in the four water phases decreased significantly, and the estrogen compounds with stronger toxicity than E1 were not produced in the photodegradation process; secondly, the toxicity of NH4-N to the photodegradation of estrogen E1 was not significant; and third, the presence of NO3-N in the process of photodegradation made water. The endocrine disrupting activity of the solution decreases faster, which may eventually lead to the mineralization of its estrogen into carbon dioxide and water.
【学位授予单位】：北京化工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X52

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