模拟日光照射下新污染物双烯雌酚的复合光化学反应动力学及转化路径  

Aqueous multivariate photochemical reaction kinetics and pathways of ionizable dienestrol under simulated sunlight irradiation

作　　者：车晓佳 郑金帅 葛林科 崔楠楠 张蓬 Xiaojia Che;inshuai Zheng;inke Ge;Nannan Cui;Peng Zhang(School of Environmental Science and Engineering,Shaanxi University of Science&Technology,Xi'an 710021,China;Lancaster Environment Centre,Lancaster University,Lancaster LAI 4YQ,United Kingdom;Shaanxi Key Laboratory for Environmental Monitoring and Forewarning of Trace Pollutants,Shaanxi Provincial Environmental Monitoring Center Station,Xi'an 710054,China)

机构地区：[1]陕西科技大学环境科学与工程学院,西安710021 [2]兰卡斯特大学兰卡斯特环境中心,兰卡斯特LA14YQ [3]陕西省环境监测中心站,陕西省环境介质痕量污染物监测预警重点实验室,西安710054

出　　处：《中国科学：化学》2024年第7期1089-1098,共10页SCIENTIA SINICA Chimica

基　　金：国家自然科学基金(编号:21976045,22076112);中国国家留学基金(编号:202308610123);陕西省环境介质痕量污染物监测预警重点实验室开放基金项目(编号:SHJKFJJ202318);陕西省重点研发计划(编号:2024SF-YBXM-567)资助项目。

摘　　要：内分泌干扰物双烯雌酚(Dien)等新污染物经常在环境表层水体中检出,并表现为多种解离形态,其光化学转化倍受关注.本文考察了Dien 3种解离形态的表观光解、羟基自由基(·OH)和单线态氧(^(1)O_(2))光氧化的反应动力学,评估了相应的环境持久性和贡献,比较了表观光解与光氧化反应的产物、路径.结果发现3种反应均能降解Dien,且光转化速率常数(k)与pH显著相关,这主要是由于Dien解离形态(i)从H_(2)Dien^(0)、HDien^(-)到Dien^(2-)发生变化,相应的k_(i)和量子产率(Φ_(i))存在差异;不同的去质子化程度也影响了其氧化反应活性,k·OH,i和k^(1)O_(2),i的变化规律一致.环境表层水体(pH=6~9,45°N)中Dien的复合光化学转化半减期t_(1/2,E)为1.84~9.16 h,^(1)O_(2)光氧化对其光化学转化贡献更大.表观光解主要引起了Dien的单羟基化;而·OH和^(1)O_(2)氧化分别发生了多羟基化,以及羟基取代位点的连续氧化反应.毒性试验表明,Dien具有光修饰毒性.这些发现有助于准确评价水环境中Dien的复合光化学归趋和风险.Environmental estrogens(EEs),typical endocrine-disrupting chemicals,were often detected as new micropollutants in the aqueous environment.With great concern,photochemical transformation plays an important role in governing the persistence of the pollutants in sunlit surface waters.Among the EEs,dienestrol(Dien)widely exists in surface waters and may dissociate with different forms.This study selected Dien as a model compound and investigated the reaction kinetics of the three dissociated forms for apparent photolysis,as well as hydroxyl radicals(·OH)and singlet oxygen(^(1)O_(2))photo-oxidation.The corresponding environmental persistence and contribution were evaluated.Furthermore,the products and pathways of the multivariate photochemical reactions were compared,and the toxicity changes were revealed during degradation process.It was observed that the apparent photolysis followed the pseudofirst-order kinetics under simulated sunlight irradiation(λ>290 nm).The rate constant(k)was obviously dependent on the solution p H,which was attributed to the changes in dissociation forms(H_(2)Dien^(0),HDien^(-)a nd Dien^(2-))as well as corresponding differences in k_(i)and quantum yields(Φ_(i)).The competition kinetic experiments further indicated that both·OH and^(1)O_(2)can degrade Dien,and the degradation rate first decreased and then sharply increased with the enhancement of p H.This was related to the diverse deprotonation degrees and photo-oxidation reactivities of the three dissociation forms.Based on the different reactivities,the integrated environmental phototransformation half-lives(t_(1/2,E))of Dien in surface water(p H=6-9)were evaluated,and the t_(1/2,E)ranged from 1.84 to 9.16 h at 45°N latitude.Compared with the apparent photolysis and·OH oxidation reactions,^(1)O_(2)photo-oxidation contributed more to the photochemical decay of Dien in surface water.Furthermore,based on the photoproduct identification with HPLC-MS/MS,it was found that the three reactions involved different primary transformation interm

关 键 词：双烯雌酚 解离形态 光转化动力学 转化机制 光修饰毒性 

分 类 号：X52[环境科学与工程—环境工程]