摘要
为深入了解夏季大气挥发性有机物(VOCs)对O_(3)污染的影响,基于上海城郊点位VOCs、O_(3)以及气象要素的在线监测数据,开展O_(3)污染时段VOCs的变化特征和活性贡献分析,研究关键气象要素和气团传输对O_(3)和VOCs的影响.结果表明,上海城郊夏季大气φ(VOCs)小时平均值为(20.91±9.82)×10^(-9),各组分构成最大的是烷烃和OVOCs,占比均为30.2%.O_(3)污染日φ(VOCs)平均值为(23.84±9.69)×10^(-9),较清洁日上升28.1%.污染日VOCs的OFP为126.9μg·m^(-3),较清洁日上升31.9%,其中烯烃OFP贡献率明显上升,丙烯和丙酮等物种较清洁日偏高最多,说明以上组分和物种需要重点加强管控.乙烷和乙炔的比值(E/E)和间/对-二甲苯与乙苯比值(X/E)的变化特征表明:上海城郊地区夏季气团存在明显的区域传输影响,且主要出现在下午和夜间.污染玫瑰图和气团后向轨迹研究结果表明,来自偏南和西南方向的气团对上海城郊VOCs体积分数的传输影响最大,尤其是来自偏南气团的烯烃和OVOCs,以及来自西南方向的芳香烃.
To help promote ozone pollution control and understand the influence of atmospheric volatile organic compounds(VOCs)on O_(3)during the summer ozone pollution season,the analyses of variation characteristics and ozone formation potentials of VOCs during O_(3)pollution episodes were carried out based on the online monitoring data of VOCs and O_(3),as well as the meteorological parameters in the suburban site of Shanghai.The impact of key meteorological factors and regional transport on O_(3)and VOCs was investigated.The results showed that the mean value of atmosphericφ(VOCs)during summer in the suburban area of Shanghai was(20.91±9.82)×10^(-9),and the largest proportion of each component was with alkanes and OVOCs,both of which were 30.2%.The mean value ofφ(VOCs)on O_(3)polluted days was(23.84±9.69)×10^(-9),which was 28.1%higher than that on clean days.The OFP of VOCs on polluted days was 126.92µg·m^(-3),which was 31.9%higher than that on clean days.The contribution of olefins to OFP accounted for a significant increase,and species such as propylene and acetone were the most significant compared to on clean days,indicating that these components and species need to be the focus of mitigation.The variation characteristics of the ratio of ethane to acetylene(E/E)and the ratio of m/p-xylene to ethylbenzene(X/E)indicated that there was a significant regional transport influence of the summer air masses in the suburban area of Shanghai,and it occurred mainly in the afternoon and at night.The results of the pollution rose diagram and the backward trajectory of air masses indicated that air masses from the south and southwest directions had the greatest influence on the transport of VOCs in suburban Shanghai.In particular,it is necessary to focus on controlling olefin and OVOCs from southern air masses and aromatic hydrocarbons from southwestern air masses.
作者
王茜
WANG Qian(Shanghai Environmental Monitoring Center,Shanghai 200235,China;Department of Environmental Science and Engineering,Fudan University,Shanghai 200438,China)
出处
《环境科学》
EI
CAS
CSCD
北大核心
2024年第8期4440-4447,共8页
Environmental Science
基金
国家重点研发计划项目(2022YFC3703504,2022YFC3703501)。
