高原河流中有机滤光剂的光解动力学及影响因素研究  

Photodegradation Kinetics and Influencing Factors of UV Filters in Plateau River

作　　者：王莹 陆光华 WANG Ying;LU Guanghua(Water Conservancy Project&Civil Engineering College,Tibet Agriculture&Animal Husbandry University,Nyinchi 860000,China;College of Environment,Hehai University,Nanjing 210098,China)

机构地区：[1]西藏农牧学院水利土木工程学院,西藏林芝860000 [2]河海大学环境学院,江苏南京210098

出　　处：《高原农业》2022年第2期180-188,共9页Journal of Plateau Agriculture

基　　金：国家自然科学基金项目(51879228);西藏农牧学院研究生教育创新计划项目(YJS2021-27)。

摘　　要：为了掌握高海拔河流中新型污染物的光解行为,以雅鲁藏布江中检出的8种有机滤光剂(Organic UV Filters,UV-Fs)为目标污染物,对比研究了不同光源下水中UV-Fs的光解动力学,分析pH、腐殖酸(HA)和NO_(3)^(-)-对典型UV-Fs光解的影响,并通过猝灭试验探究其光解机理。结果表明,在汞灯照射下8种UV-Fs的光解速率常数均高于氙灯,不同光源下河水中UV-Fs的光解速率都高于纯水。随着pH值升高和NO_(3)^(-)-浓度的增加,甲氧基肉桂酸乙基己酯(2-ethylhexyl-4-methoxycinnamate,EHMC)的光解速率降低,而1~10 mg/L的HA促进了EHMC的光解。EHMC在纯水中的光解过程以直接光解为主,同时存在由^(1)O_(2)主导的自敏化光解反应,而添加HA的溶液在光照下产生^(3)DOM^(*),促进了EHMC的间接光解。To understand the photolysis behavior of emerging contaminants in high-altitude rivers,this study investigated the photodegradation kinetics of eight organic UV filters(UV-Fs)in the Yarlung Zangbo River under different light sources,and analyzed the effects of pH,humic acid(HA)and NO_(3)^(-)-on the photodegradation of typical UV-Fs,and explored potential photodegradation mechanism.The results showed that the photodegradation rate constants(k)of eight UV-Fs under mercury lamp irradiation were higher than those under xenon lamp irradiation,and the k values of UV-Fs in river water were higher than these in ultrapure water under the two light sources.The photodegradation rates of ethylhexyl methoxycinnamate(EHMC)decreased with the increase of pH and NO_(3)^(-)-concentration,while 1~10 mg/L of HA promoted EHMC photodegradation.The photolysis process of EHMC in ultrapure water was mainly direct photolysis,accompanied by self-sensitized photodegradation reaction dominated by ^(1)O_(2),and ^(3)DOM^(*)was produced under the light in the solution with HA promoting the indirect photolysis of EHMC.

关 键 词：雅鲁藏布江 有机滤光剂 光解动力学 光解机理 

分 类 号：X835[环境科学与工程—环境工程]