High abundances of dicarboxylic acids, oxocarboxylic acids, and α-dicarbonyls in fine aerosols (PM2.5) in Chengdu, China during wintertime haze pollution
High abundances of dicarboxylic acids, oxocarboxylic acids, and α-dicarbonyls in fine aerosols (PM2.5) in Chengdu, China during wintertime haze pollution
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DOI：
10.1007/s11356-015-4548-x
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发表时间：
2015-04
影响因子：
5.8
通讯作者：
Xiao-dong Li;Zhou Yang;P. Fu;Jing Yu;Yunchao Lang;Di Liu;K. Ono;K. Kawamura
中科院分区：
文献类型：
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作者：
Xiao-dong Li;Zhou Yang;P. Fu;Jing Yu;Yunchao Lang;Di Liu;K. Ono;K. Kawamura
2013 年 1 月雾霾期间，在中国西南部成都市区采集了白天和夜间细小气溶胶 (PM2.5) 样本。分析了气溶胶样品中的低分子量同系二羧酸、氧代羧酸和 α-二羰基，以及有机碳和元素碳。二酸、含氧酸和 α-二羰基的浓度范围分别为 1,400–5,250、272–1,380 和 88–220 ng m−3。二酸的分子分布（平均 3,388 ± 943 ng m−3）以草酸（C2；1,373± 427 ng m−3）为主，其次是琥珀酸 (C4)、对苯二甲酸 (tPh) 和邻苯二甲酸 (Ph)。如此高的 tPh 和 Ph 水平与其他亚洲城市不同，在其他亚洲城市，丙二酸 (C3) 是第二或第三高的物种，这主要是由于煤炭燃烧和不受控制的废物焚烧产生的大量排放。在雾天检测到高含量的二酸、含氧酸和α-二羰基化合物，表明在这种天气条件下这些有机物的排放和/或形成增强。不饱和脂肪族二酸（例如马来酸）和邻苯二甲酸的浓度在夜间高于白天。白天，C2 与 C3、C4、酮丙二酸 (kC3)、丙酮酸 (Pyr) 和乙醛酸 (ɷC2) 呈良好正相关，表明通过长链二酸和 ɷC2 的光氧化产生 C2。本研究表明，一次排放和二次生产都是四川盆地大气气溶胶中二羧酸及相关化合物的重要来源。
Daytime and nighttime fine aerosol (PM2.5) samples were collected during a haze episode in January 2013 within the urban area of Chengdu, southwest China. Aerosol samples were analyzed for low-molecular-weight homologous dicarboxylic acids, oxocarboxylic acids and α-dicarbonyls, as well as organic carbon and elemental carbon. Concentration ranges of diacids, oxoacids, and α-dicarbonyls were 1,400–5,250, 272–1,380, and 88–220 ng m−3, respectively. Molecular distributions of diacids (mean 3,388 ± 943 ng m−3) were characterized by a predominance of oxalic acid (C2; 1,373 ± 427 ng m−3), followed by succinic (C4), terephthalic (tPh), and phthalic (Ph) acids. Such high levels of tPh and Ph were different from those in other Asian cities where malonic acid (C3) is the second or third highest species, mostly owing to significant emissions from coal combustion and uncontrolled waste incineration. High contents of diacids, oxoacids, and α-dicarbonyls were detected on hazy days, suggesting an enhanced emission and/or formation of these organics during such a weather condition. Concentrations of unsaturated aliphatic diacids (e.g., maleic acid) and phthalic acids were higher in nighttime than in daytime. Good positive correlations of C2with C3, C4, ketomalonic (kC3), pyruvic (Pyr), and glyoxylic (ɷC2) acids in daytime suggest secondary production of C2via the photooxidation of longer chain diacids and ɷC2. This study demonstrated that both primary emissions and secondary production are important sources of dicarboxylic acids and related compounds in atmospheric aerosols in the Sichuan Basin.