摘要
为探讨复合污染条件下气溶胶的消光特性,选取成都市O;与PM_(2.5)同步污染的春季开展气溶胶组分与消光特性观测,并结合美国IMPROVE化学消光算法研究了组成与消光特征的关系。结果表明,2018年春季成都PM_(2.5)平均浓度与散射系数b;分别为(50.3±22.4)μg·m^(-3)和(237.5±140.2)Mm^(-1),且二者均呈现"单峰单谷"的日变化趋势;大气气溶胶的消光系数为(268.4±153.7)Mm^(-1),对其贡献最大的组分是NH4NO(x)(26.0%)和有机物(OM)(24.4%)。分析表明在PM_(2.5)与O;复合污染情况下,二次污染组分SNA(SO_(4)^(2-)、NO(3)^(-)、NH_(4)^(4)三者之和)、二次有机碳(SOC)的含量显著增加,与清洁天相比分别升高了1.0和1.3倍;OM成为最大消光贡献者(32.2%),其次是NH_(4)NO_(3)和(NH_(3));SO_(2),分别贡献22.8%和20.5%。因此,进一步减少气态前体物如SO_(2)、NO(x)、NH_(3)和VOCs的排放可以有效改善成都地区空气质量和能见度。
To explore the aerosol chemical extinction during complex air pollution,a field campaign was carried out to investigate the composition and extinction characteristics of PM_(2.5) in spring when O;and PM_(2.5) combined pollution occurred in Chengdu,China,and the relationship between chemical composition and extinction characteristics was studied using the chemical extinction algorithm proposed by IMPROVE in the United States.The results showed that the average concentration of PM_(2.5)and scattering coefficient bspin the spring of 2018 in Chengdu were(50.3±22.4)μg·m^(-3) and (237.5±140.2)Mm^(-1),respectively,and both of them showed the similar diurnal variation trend with“single peak and single valley”.The extinction coefficient of spring PM_(2.5) in Chengdu was(268.4±153.7)Mm^(-1),and the chemical components that contributed the most to it were NH_(4)NO_(3)(26.0%)and organic matter(OM)(24.4%).In the case of PM_(2.5) and O;combined pollution,the mass of secondary pollution components(SNA(SO_(4)^(2-),NO(3)^(-),NH_(4)^(4))and secondary organic carbon(SOC)increased significantly,which increased by 1.0 and 1.3 times respectively compared with the clean day,and OM became the largest extinction contributor(32.2%),followed by NH_(4)NO_(3) and (NH_(3));SO_(2),contributing 22.8%and 20.5%respectively.Therefore,it is shown that further reducing the emission of precursor gases such as SO_(2),NO(x),NH_(3) and VOCs may be efficient to improve the air quality and visibility in Chengdu district.
作者
罗琼
冯淼
宋丹林
周力
陆成伟
杨复沫
LUO Qiong;FENG Miao;SONG Danlin;ZHOU Li;LU Chengwei;YANG Fumo(College of Environmental and Chemical Engineering,Chongqing Three Gorges University,Chongqing 404020,China;College of Architecture&Environment,Sichuan University,Chengdu 610065,China;Chengdu Academy of Environmental Sciences,Chengdu 610072,China)
出处
《大气与环境光学学报》
CAS
CSCD
2022年第1期148-159,共12页
Journal of Atmospheric and Environmental Optics
基金
国家自然科学基金项目,41875162。
