2017年春季常州 HONO观测及对大气氧化能力影响的评估  

HONO Observation and Assessment of the Effects of Atmospheric Oxidation Capacity in Changzhou During the Springtime of 2017

作　　者：施晓雯 戈逸峰 张玉婵 马嫣[1,2] 郑军[1,2] SHI Xiao-wen;GE Yi-feng;ZHANG Yu-chan;MA Yan;ZHENG Jun(School of Environmental Science and Engineering,Nanjing University of Information Science&Technology,Nanjing 210044,China;Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control,Nanjing University of Information Science&Technology,Nanjing 210044,China)

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]南京信息工程大学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

出　　处：《环境科学》2020年第3期1123-1131,共9页Environmental Science

基　　金：国家重点研发计划项目(2016YFC0202401);国家自然科学基金项目(41575122,41730106,91644213)。

摘　　要：本研究于2017年4月在江苏省常州市环境监测中心使用一套基于湿化学法的仪器对大气中的HONO进行了实时在线观测,HONO浓度范围在0.2~13.9μg·m^-3之间,平均值为(2.9±2.3)μg·m^-3;同时,对O3、HCHO、VOCs、光解频率以及气象参数进行了同步监测.利用MCM箱体模式模拟得到白天·OH浓度最大值范围在1.0×10^6~1.4×10^7个·cm^-3之间.同时结合观测结果与模式模拟结果计算了HONO、O3、HCHO和H2O2的光解以及烯烃臭氧化反应对·OH的生成速率,定量表征大气氧化性,揭示了这5种来源对大气氧化能力的影响:整体上O3光解(46.4%)>HONO光解(41.1%)>烯烃臭氧化反应(10.9%)>HCHO光解(1.5%)>H2O2光解(0.1%);清晨时HONO光解对·OH生成起主要作用,之后随着O3浓度的增加,O3光解对·OH的贡献占主导地位;在17:00之后,由于太阳光解频率显著降低,烯烃臭氧化反应对·OH生成有主要贡献;甲醛与过氧化氢的光解对·OH的贡献可忽略.HONO measurement was conducted using a wet-chemistry-based method at the Changzhou Environmental Monitoring Center in April 2017.HONO ranged from 0.2-13.9μg·m^-3 with an average of(2.9±2.3)μg·m^-3.O3,HCHO,volatile organic compounds,photolysis frequency,and meteorological parameters were simultaneously monitored.·OH concentration was simulated by a Master Chemical Mechanism box model and the daytime maximum·OH concentration ranged from 1.0×10^6 to 14×10^6 molecules per cubic centimeter.The formation rates of·OH by photolysis of HONO,O3,HCHO,H2O2,and alkene ozonolysis were calculated as well.The effects of the five sources on atmospheric oxidation capacity were revealed:O3 photolysis(46.4%)>HONO photolysis(41.1%)>alkene ozonolysis(10.9%)>HCHO photolysis(1.5%)>H2O2 photolysis(0.1%).HONO photolysis for OH radical production played a major role in the early morning,before with an increase in O3 concentration,O3 photolysis began to account for most of the·OH production.After 17:00,due to a significant decrease in the intensity of solar radiation,the alkene ozonolysis started playing a major role in the formation of·OH.The photolysis of formaldehyde and hydrogen peroxide played a negligible role in·OH radical production in this study.

关 键 词：亚硝酸 大气氧化能力 氢氧自由基生成速率 异相化学 

分 类 号：X131.1[环境科学与工程—环境科学] X511