本文關(guān)鍵詞： 17α-乙炔基雌二醇 光降解 胡敏酸 光化學(xué)活性 活性物質(zhì) 雌激素　出處：《昆明理工大學(xué)》2017年博士論文　論文類型：學(xué)位論文

【摘要】：環(huán)境中的類固醇雌激素(SEs)是一類典型的內(nèi)分泌干擾物,其可通過(guò)環(huán)境介質(zhì)和食物鏈進(jìn)入動(dòng)物和人體內(nèi)干擾天然激素的合成、分泌、運(yùn)輸和代謝等過(guò)程,進(jìn)而影響生物體發(fā)育、生長(zhǎng)和繁殖等生理過(guò)程。其中,17α-乙炔基雌二醇(EE2)是SEs中雌激素活性最強(qiáng)者,即使其環(huán)境濃度低于1.0 ng/L,也會(huì)對(duì)生態(tài)系統(tǒng)造成危害。近年來(lái),許多國(guó)家的污水處理廠出水、環(huán)境地表水甚至自來(lái)水都被檢測(cè)出了 EE2。因此,除對(duì)EE2生產(chǎn)和使用進(jìn)行有效管理外,準(zhǔn)確認(rèn)識(shí)其環(huán)境行為,為其環(huán)境風(fēng)險(xiǎn)評(píng)估和污染控制措施建立提供理論依據(jù)也是刻不容緩的。EE2 一旦進(jìn)入環(huán)境地表水體,便會(huì)經(jīng)歷各種遷移轉(zhuǎn)化過(guò)程。其中,光化學(xué)降解是EE2環(huán)境行為的重要組成部分。由于天然有機(jī)質(zhì)(NOM)是環(huán)境水體中廣泛存在的一類光敏性和濾光性物質(zhì),因此探究NOM對(duì)EE2光化學(xué)轉(zhuǎn)化的影響是認(rèn)識(shí)EE2在環(huán)境水體中的光化學(xué)行為規(guī)律和生態(tài)風(fēng)險(xiǎn)的關(guān)鍵。然而,關(guān)于NOM介導(dǎo)下的EE2光化學(xué)行為、轉(zhuǎn)化機(jī)制及雌激素活性變化等信息至今尚不清晰。再者,NOM的結(jié)構(gòu)和性質(zhì)極為復(fù)雜,其對(duì)有機(jī)污染物光化學(xué)轉(zhuǎn)化的介導(dǎo)效應(yīng)和機(jī)制常隨污染物種類及NOM理化性質(zhì)不同而異。這便意味著,NOM對(duì)EE2光化學(xué)轉(zhuǎn)化的影響不能簡(jiǎn)單地參考現(xiàn)有研究結(jié)論。因此,本文以NOM的主要組分胡敏酸(HA)為代表物質(zhì),首先系統(tǒng)地研究了 EE2在HA介導(dǎo)下的光化學(xué)轉(zhuǎn)化過(guò)程和機(jī)制,以及各水環(huán)境因子對(duì)HA介導(dǎo)EE2光化學(xué)轉(zhuǎn)化機(jī)制的影響。然后,探究了光化學(xué)轉(zhuǎn)化對(duì)EE2雌激素活性和植物生長(zhǎng)毒性的影響。最后,在明確光漂白改變HA結(jié)構(gòu)組成、理化性質(zhì)和光化學(xué)活性的基礎(chǔ)上,分析了不同來(lái)源和理化性質(zhì)HA介導(dǎo)EE2光降解效力與自身結(jié)構(gòu)組成、理化性質(zhì)及光生活性物質(zhì)(RS)間的相關(guān)性,并探討了 HA介導(dǎo)EE2光降解的主要光活性組分和結(jié)構(gòu)。主要研究結(jié)論如下:(1)EE2在純水和HA溶液中的光化學(xué)轉(zhuǎn)化過(guò)程均服從擬一級(jí)動(dòng)力學(xué)規(guī)律。在純水溶液中,EE2能發(fā)生直接光降解和自敏化降解兩種過(guò)程,但整體光降解過(guò)程較緩慢,降解速率僅為0.0163h-1左右。在HA溶液中(5.0mgC/L),EE2主要以與HA相結(jié)合的形態(tài)存在,其主要結(jié)合機(jī)制為氫鍵、π-π作用力和疏水性分配。與EE2純水溶液光降解相比,HA能有效提高EE2光降解速率4倍左右,并縮減EE2半衰期至10 h以內(nèi)。(2)EE2在HA溶液中的快速光降解主要由光生HO·和~3HA*引起,二者對(duì)EE2光降解的貢獻(xiàn)分別約為34%和30%。其中,HO·與EE2主要發(fā)生了親電加成反應(yīng);而~3HA*與EE2間的主要反應(yīng)機(jī)制為氫原子和電子抽取。盡管HA溶液中光生~1O2的量通常高出光生HO·量3個(gè)數(shù)量級(jí),但其對(duì)EE2光降解的貢獻(xiàn)始終小于17%。另外,光生H2O2和O2·-均不能直接導(dǎo)致EE2轉(zhuǎn)化,但二者都能轉(zhuǎn)化生成HO·,從而引起EE2降解。除RS外,HA結(jié)合作用也是EE2在HA溶液中發(fā)生快速光降解的原因之一,這是因?yàn)镋E2與HA相結(jié)合時(shí)有利于EE2與HO·和~3HA*發(fā)生反應(yīng)。(3)酚結(jié)構(gòu)是EE2分子中的光敏感結(jié)構(gòu),EE2在純水和HA溶液中的光降解產(chǎn)物均主要由酚環(huán)變化產(chǎn)生。在HA溶液中,盡管EE2能發(fā)生快速的光化學(xué)轉(zhuǎn)化過(guò)程,但EE2不能被徹底礦化,只能被轉(zhuǎn)化成其他有機(jī)化合物。經(jīng)酵母菌和MCF-7細(xì)胞檢測(cè)顯示,光化學(xué)轉(zhuǎn)化能徹底消除EE2雌激素活性。但值得注意的是,EE2對(duì)水稻、小麥和紅豆種子發(fā)芽及其幼苗生長(zhǎng)的刺激效應(yīng)并不能被光化學(xué)轉(zhuǎn)化徹底消除。(4)各水環(huán)境因子影響EE2光降解過(guò)程的規(guī)律如下:在純水和HA溶液中,EE2光降解速率均隨自身濃度增大呈現(xiàn)出先減小后趨于穩(wěn)定的變化趨勢(shì);在pH = 6.5～8.5的溶液中,EE2光降解速率最小,當(dāng)pH9.0時(shí),EE2光降解速率顯著增大;OO和Fe(111)均能促進(jìn)EE2光化學(xué)轉(zhuǎn)化。離子強(qiáng)度和C1-對(duì)EE2純水溶液光降解沒(méi)有影響,但二者分別能促進(jìn)和抑制HA溶液中EE2的光降解過(guò)程。HC03-對(duì)EE2在純水和HA溶液中的光降解過(guò)程均沒(méi)有影響。NO3-能顯著促進(jìn)EE2光降解,但其促進(jìn)作用會(huì)受到HA的濾光作用和HO·淬滅作用的影響。(5)光漂白能顯著改變HA的組成、結(jié)構(gòu)和理化性質(zhì)。光漂白使HA優(yōu)先失去長(zhǎng)波光吸收能力并使其分解成脂肪性組分和小分子有機(jī)酸等,從而提高HA的生物可利用性。盡管HA光生HO·、~1O2和~3HA*的能力均隨光漂白程度增大而減小,但光漂白70h后的HA仍能有效地介導(dǎo)EE2光降解,其降解速率約為純水中EE2光降解速率的2.5倍。(6)HA的光化學(xué)活性與自身疏水性、極性和分子量大小密切相關(guān)。不同疏水性組分中,過(guò)渡性親水組分具有最高的光化學(xué)活性,疏水性組分次之,親水性組分最小;HA光生HO·、~1O2和~3HA*的能力隨極性和分子量增大而減小。從結(jié)構(gòu)上看,HA介導(dǎo)EE2光降解的能力是由含氧官能團(tuán)、電子轉(zhuǎn)移復(fù)合結(jié)構(gòu)、芳香化程度和分子大小主導(dǎo)的。一定HA濃度下,光譜斜率比(S275-295/S350-400)能有效指示HA介導(dǎo)EE2光降解的能力,且這種指示作用不受低濃度H202和NaClO改變HA結(jié)構(gòu)和性質(zhì)的影響。以上研究結(jié)論一方面有利于我們更清晰地認(rèn)識(shí)EE2光化學(xué)行為和HA光化學(xué)過(guò)程在污染物環(huán)境地球化學(xué)行為中的作用;另一方面,能為EE2的環(huán)境歸趨預(yù)測(cè)、生態(tài)風(fēng)險(xiǎn)評(píng)價(jià)及污染控制措施建立等提供必要的理論依據(jù)。
[Abstract]:In the environment of steroid estrogens (SEs) is a kind of typical endocrine disruptors, which can be achieved by the environmental medium and food chain into the synthesis of natural hormones in animal and human disturbance secretion, transport and metabolism, thereby affecting the organism development, growth and reproduction and other physiological processes. Among them, 17 ethinyl estradiol glycol (EE2) is the strongest estrogenic activity in the SEs environment, even if its concentration is lower than 1 ng/L, will cause harm to the ecosystem. In recent years, sewage treatment plant effluent in many countries, the environment of surface water and even tap water were detected in the EE2. so, in addition to the effective management of EE2 production and use, accurate understanding the environmental behavior, provided theoretical basis for the establishment of the environmental risk assessment and pollution control measures are imperative for.EE2 once in the surface water, it will go through all kinds of migration and transformation process. Among them, actinic Study of degradation is an important part of the environmental behavior of EE2. Because the natural organic matter (NOM) is widely existed in aquatic environment a kind of photosensitive and filter material, thus exploring the impact of NOM on the transformation of EE2 is the key to understanding the photochemical photochemical behavior of EE2 in environmental water and ecological risk. However, EE2 on the photochemical behavior of NOM mediated transformation mechanism, and estrogenic activity changes of information is still not clear. Furthermore, the structure and properties of NOM is very complex, the organic pollutants in photochemical transformation mediated by the effect and mechanism of pollutants and NOM often vary in different physical and chemical properties vary. This means that the effect of NOM on the transformation of EE2 photochemistry can not simply refer to the existing research results. Therefore, this paper takes the main components of NOM acid (HA) as the representative of Hu Min, the first systematic study of EE2 in HA mediated photochemical conversion process And the mechanism and the influence factors of water environment by EE2 on HA mediated photochemical conversion mechanism. Then, explores the effects of transforming growth toxicity on EE2 photochemical activity and plant estrogen. Finally, in the clear light bleaching to change the structure of HA. The basic physicochemical properties and photochemical activity, analysis of different sources and physicochemical the properties of HA mediated EE2 degradation effect of composition and its structure, physicochemical properties and optical active substances (RS) and to explore the correlation between, HA mediated EE2 degradation of main light active components and structure. The main conclusions are as follows: (1) EE2 in water and HA solution in the photochemical transformation the process follows pseudo first-order kinetics. In aqueous solution, EE2 can direct photodegradation and self sensitized degradation of two kinds of process, but the overall degradation process is slow, the degradation rate is only about 0.0163h-1. In the solution of HA (5.0mgC /L), mainly in the EE2 涓嶩A鐩哥粨鍚堢殑褰㈡，

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