pH对不同来源溶解性有机质光化学性质的影响
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- 英文论文题名：Impact of pH on Photochemical Properties of DOM from Different Sources
- 论文作者：马哲 ; 王杰琼 ; 陈景文
- 英文论文作者：Zhe Ma ; Jieqiong Wang ; Jingwen Chen ; Key Laboratory of Industrial Ecology and Environmental Engineering (MOE) ; School of Environmental Science and Technology ; Dalian University of Technology
- 年：2016
- 作者机构：工业生态与环境工程教育部重点实验室大连理工大学环境学院;
- 论文关键词：溶解性有机质 ; pH ; 光致活性物种 ; 量子产率
- 会议召开时间：2016-07-01
- 会议录名称：中国化学会第30届学术年会摘要集-第二十六分会：环境化学
- 语种：中文
- 分类号：X131.2;O644.1
- 学会代码：ZGHY
- 会议名称：中国化学会第30届学术年会-第二十六分会 ; 环境化学
- 会议地点：中国辽宁大连
- 主办单位：中国化学会
- 学会名称：中国化学会
- 页数：1
- 文件大小：304k
- 原文格式：D
- 会议级别：全国
摘要
溶解性有机质(DOM)普遍存在于天然地表水中,DOM可吸收特定波长太阳光,产生激发三线态DOM(3DOM*)、单线态氧(1O2)和羟基自由基(?OH)等光致活性物种(RPS)。这些RPS对有机污染物的降解具有重要作用。pH改变可导致DOM的粒径、官能团和分子量变化,但目前,pH与DOM光化学性质之间的关系还鲜有研究。本研究选用三种商业DOM和提取大连周边区域海水中的DOM,在模拟日光条件下,采取分子探针的方法测定DOM在pH等于4.3,7.2和9.4条件下产生3DOM*,1O2和?OH的量子产率(Φ)。结果表明,Φ(3DOM*)随pH的改变没有显著变化,Φ(1O2)在pH 4.2时有最大值(2.60±0.21)x10-2,Φ(?OH)在pH 4.3是pH 7.2和9.4的2.4~4.3倍。本研究对解释水中有机污染物的光化学归趋具有重要的环境意义。
Dissolved organic matter(DOM) exists widely in surface waters.DOM is capable of absorbing ultraviolet radiation to generate reactive photo-induced species(RPS),such as triplet excited DOM(3DOM*),singlet oxygen(1O2) and hydroxyl radicals(?OH).The RPS is important for the degradation of organic pollutants.It is known that pH variations can change the size,conformation and molecular weight of DOM.However,the relation between pH variations and photochemical properties of DOM has been rarely investigated.In the present study,the effects of pH variations on quantum yields(Φ) of 3DOM*,1O2 and ?OH were investigated by using different molecular probes and simulated sunlight experiment.Three commercial DOM and a kind of DOM extracted from coastal zones around Dalian were studied.Results show that Φ(3DOM*) does not change with pH;Φ(1O2) at pH 4.3 has the maximum value of(2.60 ± 0.21) x 10-2 and Φ(?OH) at pH 4.3 is 2.4 ~ 4.3 times higher than that at pH 7.2 and 9.4.The study is important for interpreting photochemical fate of organic pollutants in water.
Dissolved organic matter(DOM) exists widely in surface waters.DOM is capable of absorbing ultraviolet radiation to generate reactive photo-induced species(RPS),such as triplet excited DOM(3DOM*),singlet oxygen(1O2) and hydroxyl radicals(?OH).The RPS is important for the degradation of organic pollutants.It is known that pH variations can change the size,conformation and molecular weight of DOM.However,the relation between pH variations and photochemical properties of DOM has been rarely investigated.In the present study,the effects of pH variations on quantum yields(Φ) of 3DOM*,1O2 and ?OH were investigated by using different molecular probes and simulated sunlight experiment.Three commercial DOM and a kind of DOM extracted from coastal zones around Dalian were studied.Results show that Φ(3DOM*) does not change with pH;Φ(1O2) at pH 4.3 has the maximum value of(2.60 ± 0.21) x 10-2 and Φ(?OH) at pH 4.3 is 2.4 ~ 4.3 times higher than that at pH 7.2 and 9.4.The study is important for interpreting photochemical fate of organic pollutants in water.
引文
[1]Rochelle-Newall,J.;Fisher,T.R.;Mar.Chem.2002,77(1):23.