本文主要研究内容
作者洪冉（2019）在《蒙脱石介导的阿特拉津催化降解机理研究》一文中研究指出：本研究以阿特拉津(Atrazine,ATRA)和蒙脱石为主要研究对象,研究了蒙脱石对ATRA光降解的影响,以此为基础,开发出能够快速降解ATRA的“环境功能材料”,结合量子化学手段对ATRA分子“光降解”和“功能材料催化降解”过程中的降解特性进行了研究,为环境中ATRA及类似有机污染物污染治理和控制提供科学方法和理论依据。论文首先研究了自然光照条件下,铁蒙脱石(Fe3+-montmorillonite)产生的活性氧(Reactive oxygen species,ROS)降解阿特拉津的过程,起主要作用的ROS是羟基自由基(·OH),因为淬灭实验表明甲醇(Methanol)能够强烈抑制反应,且苯甲酸(Benzoic acid,BA)在系统内的反应产物为对羟基苯甲酸(para-hydroxyl benzoic acid,pHBA),是BA与·OH反应的特征产物。·OH的产生受pH控制,钠离子(Na+)的加入会提升光催化效率,是因为离子交换作用所致。阴离子对反应的影响由种类和浓度控制,若为惰性的高氯酸根(ClO4-),则没有影响;若配位阴离子为氯离子(Cl-),则表现出“低促高抑”的特性。综合考虑阴阳离子的影响,可知在低浓度的NaCl条件下,离子交换占主导,表现为促进反应,而在较高浓度的NaCl条件下,Cl-与·OH反应形成Cl·自由基,该自由基不能降解阿特拉津,从而降低了光反应效率,此时Cl-的抑制作用强于Na+的促进作用。自然光照下,富里酸(Suwannee River fulvic acid,SRFA)系统中的主要ROS是单线态氧(1O2),因为甲醇未抑制反应,而叠氮化钠则强烈抑制反应。1O2的产生不受pH影响,不同pH条件下,ATRA降解速率没有显著差异。将SRFA浓度从5 mg L-1增加到20 mg L-1反而降低了反应效率,高浓度SRFA不仅消耗自身产生的1O2,还会因发色基团产生的“遮光效应”降低有效光强。SRFA/Fe3+-montmorillonite混合系统中主要ROS种类受pH控制,低pH时为·OH,此时SRFA表现为拮抗作用;高pH时为1O2,此时Fe3+-montmorillonite产生·OH能力变弱,而不受pH影响的SRFA持续供给的1O2逐渐成为系统中主要ROS。溶解氧(Disslovedoxygen,DO)是 Fe3+-montmorillonite 系统、SRFA 系统以及SRFA/Fe3+-montmorillonite混合系统中发生氧化降解反应的必要条件。预先曝N2气都终止各个系统中的反应,在Fe3+-montmorillonite系统中,溶解氧被光致亚铁离子还原,产生的超氧自由基(O2-),质子化后形成氢过氧自由基(hydroperoxylradical,HO2),进而形成H202,在光致还原的Fe2+的催化下产生·OH降解ATRA;在SRFA系统中,溶解氧被SRFATs激活成1O2,1O2能够降解ATRA,钼酸盐-双氧水的纯1O2系统证明了这一点;高浓度SRFA可以消耗·OH和1O2并降低系统中的有效光强,厌氧实验表明SRFATS不能降解ATRA。量子化学计算证明,二价铁离子吸附在蒙脱石表面后更容易被分子氧氧化,吸附前后二价铁离子第一电离能相差0.24 eV。在充分理解蒙脱石对阿特拉津降解的影响特性后,论文的第二部分中设计并合成了零价金属铜-蒙脱石复合材料(ZVCMMT),可以在小于2 min的时间内去除95%以上的ATRA(15 μM)。初始反应速率是商业化的零价铜粉(Commercially available zero valent copper,CZVC)和在自由空间合成的纳米零价铜(nano-sized zero valent copper,nZVC)的72倍和2倍,而铜的投加量仅为上述两者的3.3%,是一种很有潜力的处理环境突发事件的环境功能材料。使用发光菌对最终溶液的毒性进行评估,结果表明,在光解后,Fe3+-montmorillonite,SRFA 和 SRFA/Fe3+-montmorillonite 三个系统中的发光抑制率分别为9.14%,4.93%和6.37%,证明系统的整体毒性随着光解而降低,且表明SRFA存在有利于缓解ATRA光反应后溶液中的毒性,鉴于Fe3+-montmorillonite和SRFA在自然界中广泛存在,此光解过程可以视为ATRA在自然界中的解毒过程。在ZVCMMT降解ATRA的实验中,发光菌的发光抑制率从反应前的25%降低到-0.53%,证明ZVCMMT处理后的含ATRA溶液的毒性显著降低,且ZVCMMT材料本身在反应后几乎没有发光菌毒性,是一种环境友好型材料。论文的第三部分使用量子化学工具研究ATRA分子特性,前线电子理论分析结果表明ATRA在羟基自由基进攻下,其反应位点为两侧支链上的N原子,但对反应位点之间的活性比较,前线电子理论的预测结果差强人意。用概念密度泛函(conceptual Density Functional Theory,CDFT)中的双描述符(Dual descriptor,DD)函数进行预测,结果同样表明ATRA分子的反应位点位于两侧支链的N原子上,乙胺基的N原子DD值为-0.1561,异丙胺基的N原子DD值为0.0134,DIA中的乙胺基的N原子DD值为-0.1596,DEA中的异丙胺基的N原子DD值为-0.1539,DEDIA中对应的两个N原子的DD值均为-0.0651,与实验结果一致,随着两侧脂肪支链的断裂,计算得到的胺基的反应活性越低,意味着在受亲电试剂进攻时越稳定。从ATRA分子中的反应位点的预测结果来看,DD优于前线电子理论。“定域化轨道定位函数”(Localized orbital locator,LOL)能够较好的研究ATRA分子的芳香性,能够直观并定量的分析ATRA分子环上电子离域性质,用LOL函数考察取代基对芳香性的影响。随着取代基的加入,ATRA分子环上的芳香性逐渐减弱,直至消失。芳香性主要源自π电子贡献,σ电子无贡献,三嗪环具有π芳香性而ATRA不具有,三嗪环的芳香性性质不能用于预测ATRA的性质。综上所述,本论文从阿特拉津的自然降解过程开始,师法自然,利用天然矿物合成出性能优异的环境功能材料,高效处理降解有机污染物,再利用量子化学方法,研究了难以直接用实际实验方法检测的分子性质:芳香性。本研究为三嗪类农药的环境行为的研究和污染治理提供了理论依据和技术支持。
Abstract
ben yan jiu yi a te la jin (Atrazine,ATRA)he meng tuo dan wei zhu yao yan jiu dui xiang ,yan jiu le meng tuo dan dui ATRAguang jiang jie de ying xiang ,yi ci wei ji chu ,kai fa chu neng gou kuai su jiang jie ATRAde “huan jing gong neng cai liao ”,jie ge liang zi hua xue shou duan dui ATRAfen zi “guang jiang jie ”he “gong neng cai liao cui hua jiang jie ”guo cheng zhong de jiang jie te xing jin hang le yan jiu ,wei huan jing zhong ATRAji lei shi you ji wu ran wu wu ran zhi li he kong zhi di gong ke xue fang fa he li lun yi ju 。lun wen shou xian yan jiu le zi ran guang zhao tiao jian xia ,tie meng tuo dan (Fe3+-montmorillonite)chan sheng de huo xing yang (Reactive oxygen species,ROS)jiang jie a te la jin de guo cheng ,qi zhu yao zuo yong de ROSshi qiang ji zi you ji (·OH),yin wei cui mie shi yan biao ming jia chun (Methanol)neng gou jiang lie yi zhi fan ying ,ju ben jia suan (Benzoic acid,BA)zai ji tong nei de fan ying chan wu wei dui qiang ji ben jia suan (para-hydroxyl benzoic acid,pHBA),shi BAyu ·OHfan ying de te zheng chan wu 。·OHde chan sheng shou pHkong zhi ,na li zi (Na+)de jia ru hui di sheng guang cui hua xiao lv ,shi yin wei li zi jiao huan zuo yong suo zhi 。yin li zi dui fan ying de ying xiang you chong lei he nong du kong zhi ,re wei duo xing de gao lv suan gen (ClO4-),ze mei you ying xiang ;re pei wei yin li zi wei lv li zi (Cl-),ze biao xian chu “di cu gao yi ”de te xing 。zeng ge kao lv yin yang li zi de ying xiang ,ke zhi zai di nong du de NaCltiao jian xia ,li zi jiao huan zhan zhu dao ,biao xian wei cu jin fan ying ,er zai jiao gao nong du de NaCltiao jian xia ,Cl-yu ·OHfan ying xing cheng Cl·zi you ji ,gai zi you ji bu neng jiang jie a te la jin ,cong er jiang di le guang fan ying xiao lv ,ci shi Cl-de yi zhi zuo yong jiang yu Na+de cu jin zuo yong 。zi ran guang zhao xia ,fu li suan (Suwannee River fulvic acid,SRFA)ji tong zhong de zhu yao ROSshi chan xian tai yang (1O2),yin wei jia chun wei yi zhi fan ying ,er die dan hua na ze jiang lie yi zhi fan ying 。1O2de chan sheng bu shou pHying xiang ,bu tong pHtiao jian xia ,ATRAjiang jie su lv mei you xian zhe cha yi 。jiang SRFAnong du cong 5 mg L-1zeng jia dao 20 mg L-1fan er jiang di le fan ying xiao lv ,gao nong du SRFAbu jin xiao hao zi shen chan sheng de 1O2,hai hui yin fa se ji tuan chan sheng de “zhe guang xiao ying ”jiang di you xiao guang jiang 。SRFA/Fe3+-montmorillonitehun ge ji tong zhong zhu yao ROSchong lei shou pHkong zhi ,di pHshi wei ·OH,ci shi SRFAbiao xian wei jie kang zuo yong ;gao pHshi wei 1O2,ci shi Fe3+-montmorillonitechan sheng ·OHneng li bian ruo ,er bu shou pHying xiang de SRFAchi xu gong gei de 1O2zhu jian cheng wei ji tong zhong zhu yao ROS。rong jie yang (Disslovedoxygen,DO)shi Fe3+-montmorillonite ji tong 、SRFA ji tong yi ji SRFA/Fe3+-montmorillonitehun ge ji tong zhong fa sheng yang hua jiang jie fan ying de bi yao tiao jian 。yu xian bao N2qi dou zhong zhi ge ge ji tong zhong de fan ying ,zai Fe3+-montmorilloniteji tong zhong ,rong jie yang bei guang zhi ya tie li zi hai yuan ,chan sheng de chao yang zi you ji (O2-),zhi zi hua hou xing cheng qing guo yang zi you ji (hydroperoxylradical,HO2),jin er xing cheng H202,zai guang zhi hai yuan de Fe2+de cui hua xia chan sheng ·OHjiang jie ATRA;zai SRFAji tong zhong ,rong jie yang bei SRFATsji huo cheng 1O2,1O2neng gou jiang jie ATRA,mu suan yan -shuang yang shui de chun 1O2ji tong zheng ming le zhe yi dian ;gao nong du SRFAke yi xiao hao ·OHhe 1O2bing jiang di ji tong zhong de you xiao guang jiang ,ya yang shi yan biao ming SRFATSbu neng jiang jie ATRA。liang zi hua xue ji suan zheng ming ,er jia tie li zi xi fu zai meng tuo dan biao mian hou geng rong yi bei fen zi yang yang hua ,xi fu qian hou er jia tie li zi di yi dian li neng xiang cha 0.24 eV。zai chong fen li jie meng tuo dan dui a te la jin jiang jie de ying xiang te xing hou ,lun wen de di er bu fen zhong she ji bing ge cheng le ling jia jin shu tong -meng tuo dan fu ge cai liao (ZVCMMT),ke yi zai xiao yu 2 minde shi jian nei qu chu 95%yi shang de ATRA(15 μM)。chu shi fan ying su lv shi shang ye hua de ling jia tong fen (Commercially available zero valent copper,CZVC)he zai zi you kong jian ge cheng de na mi ling jia tong (nano-sized zero valent copper,nZVC)de 72bei he 2bei ,er tong de tou jia liang jin wei shang shu liang zhe de 3.3%,shi yi chong hen you qian li de chu li huan jing tu fa shi jian de huan jing gong neng cai liao 。shi yong fa guang jun dui zui zhong rong ye de du xing jin hang ping gu ,jie guo biao ming ,zai guang jie hou ,Fe3+-montmorillonite,SRFA he SRFA/Fe3+-montmorillonite san ge ji tong zhong de fa guang yi zhi lv fen bie wei 9.14%,4.93%he 6.37%,zheng ming ji tong de zheng ti du xing sui zhao guang jie er jiang di ,ju biao ming SRFAcun zai you li yu huan jie ATRAguang fan ying hou rong ye zhong de du xing ,jian yu Fe3+-montmorillonitehe SRFAzai zi ran jie zhong an fan cun zai ,ci guang jie guo cheng ke yi shi wei ATRAzai zi ran jie zhong de jie du guo cheng 。zai ZVCMMTjiang jie ATRAde shi yan zhong ,fa guang jun de fa guang yi zhi lv cong fan ying qian de 25%jiang di dao -0.53%,zheng ming ZVCMMTchu li hou de han ATRArong ye de du xing xian zhe jiang di ,ju ZVCMMTcai liao ben shen zai fan ying hou ji hu mei you fa guang jun du xing ,shi yi chong huan jing you hao xing cai liao 。lun wen de di san bu fen shi yong liang zi hua xue gong ju yan jiu ATRAfen zi te xing ,qian xian dian zi li lun fen xi jie guo biao ming ATRAzai qiang ji zi you ji jin gong xia ,ji fan ying wei dian wei liang ce zhi lian shang de Nyuan zi ,dan dui fan ying wei dian zhi jian de huo xing bi jiao ,qian xian dian zi li lun de yu ce jie guo cha jiang ren yi 。yong gai nian mi du fan han (conceptual Density Functional Theory,CDFT)zhong de shuang miao shu fu (Dual descriptor,DD)han shu jin hang yu ce ,jie guo tong yang biao ming ATRAfen zi de fan ying wei dian wei yu liang ce zhi lian de Nyuan zi shang ,yi an ji de Nyuan zi DDzhi wei -0.1561,yi bing an ji de Nyuan zi DDzhi wei 0.0134,DIAzhong de yi an ji de Nyuan zi DDzhi wei -0.1596,DEAzhong de yi bing an ji de Nyuan zi DDzhi wei -0.1539,DEDIAzhong dui ying de liang ge Nyuan zi de DDzhi jun wei -0.0651,yu shi yan jie guo yi zhi ,sui zhao liang ce zhi fang zhi lian de duan lie ,ji suan de dao de an ji de fan ying huo xing yue di ,yi wei zhao zai shou qin dian shi ji jin gong shi yue wen ding 。cong ATRAfen zi zhong de fan ying wei dian de yu ce jie guo lai kan ,DDyou yu qian xian dian zi li lun 。“ding yu hua gui dao ding wei han shu ”(Localized orbital locator,LOL)neng gou jiao hao de yan jiu ATRAfen zi de fang xiang xing ,neng gou zhi guan bing ding liang de fen xi ATRAfen zi huan shang dian zi li yu xing zhi ,yong LOLhan shu kao cha qu dai ji dui fang xiang xing de ying xiang 。sui zhao qu dai ji de jia ru ,ATRAfen zi huan shang de fang xiang xing zhu jian jian ruo ,zhi zhi xiao shi 。fang xiang xing zhu yao yuan zi πdian zi gong suo ,σdian zi mo gong suo ,san qin huan ju you πfang xiang xing er ATRAbu ju you ,san qin huan de fang xiang xing xing zhi bu neng yong yu yu ce ATRAde xing zhi 。zeng shang suo shu ,ben lun wen cong a te la jin de zi ran jiang jie guo cheng kai shi ,shi fa zi ran ,li yong tian ran kuang wu ge cheng chu xing neng you yi de huan jing gong neng cai liao ,gao xiao chu li jiang jie you ji wu ran wu ,zai li yong liang zi hua xue fang fa ,yan jiu le nan yi zhi jie yong shi ji shi yan fang fa jian ce de fen zi xing zhi :fang xiang xing 。ben yan jiu wei san qin lei nong yao de huan jing hang wei de yan jiu he wu ran zhi li di gong le li lun yi ju he ji shu zhi chi 。
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论文详细介绍
论文作者分别是来自南京大学的洪冉，发表于刊物南京大学2019-05-27论文，是一篇关于三嗪类农药论文,蒙脱石论文,光催化论文,零价金属论文,分子氧活化论文,羟基自由基论文,单线态氧论文,量子化学计算论文,南京大学2019-05-27论文的文章。本文可供学术参考使用，各位学者可以免费参考阅读下载，文章观点不代表本站观点，资料来自南京大学2019-05-27论文网站，若本站收录的文献无意侵犯了您的著作版权，请联系我们删除。
标签：三嗪类农药论文; 蒙脱石论文; 光催化论文; 零价金属论文; 分子氧活化论文; 羟基自由基论文; 单线态氧论文; 量子化学计算论文; 南京大学2019-05-27论文;