不同NOx条件下有机胺光氧化二次气溶胶的形成及其云凝结核活性  

Formation and cloud condensation nuclei activity of secondary aerosol from amine photo-oxidation under different NOx conditions

作　　者：蒋友凌 马嫣[1,2] 郑军 马鑫[3] JIANG Youling;MA Yan;ZHENG Jun;MA Xin(School of Environmental Science and Engineering,Nanjing University of Information Science&Technology,Nanjing 210044;Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control,Nanjing 210044;Wuxi CAS Photonics Co.,Ltd.,Wuxi 214135)

机构地区：[1]南京信息工程大学环境科学与工程学院,南京210044 [2]江苏省大气环境监测与污染控制高技术研究重点实验室,南京210044 [3]无锡中科光电技术有限公司,无锡214135

出　　处：《环境科学学报》2023年第5期301-311,共11页Acta Scientiae Circumstantiae

基　　金：国家自然科学基金(No.41730106,41975172,42275116);国家重点研发计划(No.2016YFC0202402)。

摘　　要：本研究采用烟雾箱模拟的方法,在不同NOx条件下,对二甲胺、三甲胺、二乙胺、苯胺、乙醇胺与OH自由基光氧化生成二次气溶胶(SA)的过程及其云凝结核(CCN)活性进行了测定.结果表明,当不添加NOx时,乙醇胺的SA生成系数(FAC)最高(0.22),而三甲胺与苯胺的FAC较低(≤0.05),二甲胺与二乙胺的FAC则趋于0,且该条件下生成的气溶胶CCN活性较弱,三甲胺、苯胺与乙醇胺生成的SA吸湿性参数(κ_(SA))值为0.10~0.22,符合典型有机物κ值.当添加NOx后,各有机胺生成的SA粒径、密度变大,且SA的生成系数均有提高,在高NOx浓度条件下按SA的生成系数对有机胺排序:乙醇胺>苯胺>二甲胺>三甲胺>二乙胺;同时添加NOx后SA的CCN活性变强,在高NOx浓度条件下按其CCN活性对有机胺排序:乙醇胺>二甲胺>苯胺>二乙胺>三甲胺,其中,乙醇胺最高(κ_(SA)=0.65).此外,在光氧化过程中添加NOx可能会促进二甲胺、二乙胺、苯胺与乙醇胺生成硝酸盐,进而促进生成的气溶胶产率与CCN活性增加,而三甲胺光氧化生成的SA则以非盐类有机物为主,故在高NOx条件下虽然促进了SA产率的提升,但其CCN活性仍较低.In this study,smog chamber experiments were carried out for investigation of the process of generating secondary aerosols(SA)and their Cloud Condensation Nuclei(CCN)activity.The SA were generated through photo-oxidation of dimethylamine,trimethylamine,diethylamine,aniline,and ethanolamine with OH radicals under different NOx concentrations.It was found that the SA generation coefficient(FAC)of ethanolamine was highest(FAC=0.22),followed by aniline and trimethylamine(FAC≤0.05)in the absence of NOx,while the FAC of dimethylamine and diethylamine tended to 0 under the same condition.Besides,the CCN activities of all the aerosols were found weak in the absence of NOx.The hygroscopicity parameter(κ_(SA))of SA generated by photolysis of trimethylamine,aniline and ethanolamine were 0.10~0.22,which were consistent withκvalues of typical organics.The diameter and density of SA generated by amines,as well as the generation coefficients of SA were increased when NOx was added.Under high NOx concentration conditions,the amines can be sorted according to the generation coefficients of SA:ethanolamine>aniline>dimethylamine>trimethylamine>diethylamine.The CCN activities of SA were seen enhanced with existence of NOx,and under high NOx concentration the amines can be sorted according to the CCN activities of SA:ethanolamine>dimethylamine>aniline>diethylamine>trimethylamine.Theκ_(SA) of SA generated from ethanolamine is 0.65,which is the highest among the amines.We found that the addition of NOx during photolysis could promote the generation of nitrate from dimethylamine,diethylamine,aniline and ethanolamine,which in turn promoted their SA yield and CCN activity of SA.However,the SA products of trimethylamine photolysis were mainly non-salt organic aerosols,thus the CCN activity of SA remained low under the relatively high NOx condition although the SA yield increased.

关 键 词：烟雾箱 有机胺 二次气溶胶 云凝结核 活性 

分 类 号：X51[环境科学与工程—环境工程]