Sources and gas-particle partitioning of atmospheric parent, oxygenated, and nitrated polycyclic aromatic hydrocarbons in a humid city in southwest China
Sources and gas-particle partitioning of atmospheric parent, oxygenated, and nitrated polycyclic aromatic hydrocarbons in a humid city in southwest China
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中国西南潮湿城市大气母体、含氧和硝化多环芳烃的来源和气体颗粒分配
DOI：
10.1016/j.atmosenv.2019.02.041
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发表时间：
2019
影响因子：
5
通讯作者：
Wang Jun
中科院分区：
文献类型：
--
作者：
Hu Huilin;Tian Mi;Zhang Leiming;Yang Fumo;Peng Chao;Chen Yang;Shi Guangming;Yao Xiaojiang;Jiang Changtan;Wang Jun
多环芳烃（polycycyclic aromatic hydrocarbons，PAHs）的衍生物，如氧化多环芳烃（oxygenated PAHs，OPAH）和硝化多环芳烃（nitrated PAHs，NPAH），在环境中普遍存在，其中一些比母体多环芳烃毒性更强，更持久。2016年，在中国西南部的重庆城市环境中测量了空气中的气态和颗粒物PAHs，OPAH和NPAH。∑ 29多环芳烃、∑ 10多环芳烃和∑ 27多环芳烃的年平均浓度分别为79.9±40.5 ng/m ³、93.7±75.2 ng/m³和1.65±1.43 ng/m³。多环芳烃的浓度冬季最高，夏季最低，而NPAHs和OPAHs的浓度夏季高于春、秋季，这可能是由于NPAHs和OPAHs在夏季的次生生成较强。源解析分析表明，生物质燃烧、燃煤和石油燃烧是多环芳烃的主要来源，而二次生成（尤其是夏季）对OPAHs和NPAHs的贡献较大.多环芳烃、OPAHs和NPAHs的气/粒分配系数（logKP）与相应的过冷液体蒸气压（logPLo）有很好的相关性。多环芳烃的logKP和logPLo之间的线性回归斜率（-0.61至-0.52）比OPAH或NPAH（-2.14至-0.73）更小，表明多环芳烃更强地吸收到大气颗粒物中。评价了三种气体/颗粒分配模型，包括Junger-Pankow吸附模型、KOA吸收模型和双辛醇-空气/烟灰-空气模型。与颗粒结合分数的实测值相比，模型预测值在合理范围内的多环芳烃，但被低估的NPAH和OPAH，这表明其他重要因素，如相对湿度的影响，应纳入气/颗粒分配模型的疏水性较低的化合物，特别是在潮湿地区。
Polycyclic aromatic hydrocarbons (PAHs) derivatives, such as oxygenated PAHs (OPAHs) and nitrated PAHs (NPAHs), some of which are more toxic and persistent than parent PAHs, have been ubiquitously detected in the environment. Gaseous and particulate PAHs, OPAHs, and NPAHs in the air were measured in an urban environment of Chongqing in southwest China in 2016. Annual average concentrations were 79.9±40.5 ng/m³, 93.7±75.2 ng/m³ and 1.65±1.43 ng/m³ for∑ 29 PAHs,∑ 10 OPAHs and∑ 27 NPAHs, respectively. PAHs had highest level in winter and lowest level in summer while NPAHs and OPAHs showed relatively higher concentrations in summer than spring and autumn, which may be explained by stronger secondary formation of NPAHs and OPAHs in summer. Source apportionment analysis revealed that biomass burning, coal combustion, and petroleum combustion were the main sources for PAHs, while secondary formation, especially in summer, contributed greatly to OPAHs and NPAHs. Gas/particle partition coefficient (log K P) of PAHs, OPAHs and NPAHs, calculated from our observation data, was found to correlate well with the corresponding subcooled liquid vapor pressures (log P L o). The shallower slope of the linear regression between logK P and log P L o for PAHs (− 0.61 to− 0.52) than OPAHs or NPAHs (− 2.14 to− 0.73) indicated stronger absorption into the atmospheric particles for PAHs. Three gas/particle partitioning models were evaluated, including the Junger-Pankow adsorption model, the K OA absorption model, and the Dual octanol-air/soot-air model. Compared to the measured values of particle-bound fractions, model predicted values were in reasonable range for PAHs, but were underestimated for NPAHs and OPAHs, suggesting that other important factors such as the influence of RH should be incorporated in gas/particle partitioning models for less hydrophobic compounds, especially in humid areas.