Atmospheric deposition of polycyclic aromatic compounds and associated sources in an urban and a rural area of Chongqing, China
Atmospheric deposition of polycyclic aromatic compounds and associated sources in an urban and a rural area of Chongqing, China
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中国重庆城乡多环芳香族化合物的大气沉降及其来源
DOI：
10.1016/j.chemosphere.2017.08.077
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发表时间：
2017
期刊：
影响因子：
8.8
通讯作者：
Qiao BaoQing
中科院分区：
文献类型：
--
作者：
Tian Mi;Yang FuMo;Chen SheJun;Wang HuanBo;Chen Yang;Zhang LiuYi;Zhang LeiMing;Xiang Li;Qiao BaoQing
2014年5月至2015年4月，在重庆市城乡大气沉积物中采集了干态和湿态样品，分析了大气沉积物中多环芳烃（PPAH）和3种取代多环芳烃（SPAHs）的含量。结果表明，城市和农村大气中三种多环芳烃的年平均沉降通量分别为536 ± 216、221 ± 118和131 ± 41.9 ng/m2/d，农村分别为347 ± 185、160 ± 112和85.2 ± 32.0 ng/m2/d。结果表明，NPAHs的沉降量（6.01 ± 3.93和3.91 ± 4.84 ng/m2/d）比PPAHs的沉降量低两个数量级。在城市地区，PPAHs和MPAHs通量的时间变化与颗粒物沉降呈正相关，而OPAHs和NPAHs的趋势可能是由次生形成控制。在农村地区，SPAHs和PPAHs的沉降通量有相似的时间趋势，但不同的颗粒物沉降。重庆冬季相对湿度较高可能是促使OPAHs向大气气溶胶中分配的重要因素，也是导致OPAHs浓度相对较高的主要原因。主成分分析表明，二次形成（21.7%）和燃烧排放（52.7%）的多环芳烃（PACs）的沉积通量在城市地区的两个重要贡献者。
Monthly bulk (dry + wet) deposition samples were collected at an urban and a rural site in Chongqing, southwestern China during May 2014 to April 2015 for analyzing the contents of parent polycyclic aromatic hydrocarbons (PPAHs) and three types of substituted PAHs (SPAHs) including oxygenated PAHs (OPAHs), nitrated PAHs (NPAHs) and methyl PAHs (MPAHs). Annual average (±standard deviation) deposition fluxes of ΣPPAHs, ΣOPAHs, and ΣMPAHs were 536 ± 216; 221 ± 118, and 131 ± 41.9 ng/m2/d, respectively, in the urban area, and 347 ± 185, 160 ± 112, and 85.2 ± 32.0 ng/m2/d, respectively in the rural area. Deposition of ΣNPAHs (6.01 ± 3.93 and 3.91 ± 4.84 ng/m2/d) were about two orders of magnitude lower than those of ΣPPAHs. In the urban area, temporal variations of PPAHs and MPAHs fluxes were positively correlated with particle deposition, while the trends of OPAHs and NPAHs were probably controlled by secondary formation. In the rural area, SPAHs and PPAHs deposition fluxes had similar temporal trends but differed from particle deposition. High relative humidity in Chongqing likely played an important role in facilitating the partitioning of OPAHs to atmospheric aerosols and resulting in the relatively high OPAHs level in winter. Principle component analysis identified secondary formation (21.7%) and combustion emission (52.7%) as two important contributors to polycyclic aromatic compounds (PACs) deposition fluxes in urban area.