Molecular Distributions of Diacids, Oxoacids, and α-Dicarbonyls in Summer- and Winter-Time Fine Aerosols From Tianjin, North China: Emissions From Combustion Sources and Aqueous Phase Secondary Formation
Molecular Distributions of Diacids, Oxoacids, and α-Dicarbonyls in Summer- and Winter-Time Fine Aerosols From Tianjin, North China: Emissions From Combustion Sources and Aqueous Phase Secondary Formation
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华北天津夏季和冬季细小气溶胶中二酸、含氧酸和α-二羰基的分子分布：燃烧源和水相二次形成的排放
DOI：
10.1029/2020jd032961
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发表时间：
2020
期刊：
影响因子：
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通讯作者：
Cong-Qiang Liu
中科院分区：
文献类型：
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作者：
Ch;ra Mouli Pavuluri;Shuang Wang;Pingqing Fu;Wanyu Zhao;Zhanjie Xu;Cong-Qiang Liu
为了解华北地区有机气溶胶（OA）的特征和来源，研究了天津地区夏季和冬季PM2. 5中二元酸、含氧酸和α-二羰基化合物的含量。草酸（C2）被认为是最丰富的二酸物种，其次是琥珀酸（C4），丙二酸（C3），癸二酸（C8），分别。乙醛酸（ωC2）是最丰富的含氧酸，其次是甘草酸。冬季总二酸、含氧酸和α-二羰基化合物的浓度比夏季高2-3倍，但它们在PM2. 5中的质量分数却恰恰相反。夏季总二酸碳占总碳的2.9%，占有机碳的3.3%，冬季分别占1.8%和2.0%。它们对水溶性有机碳（WSOC）的贡献在两个季节几乎相同（分别为5.5%和5.3%）。选定二元酸的分子分布、质量比（C3、C4、M、F、C6、Ph和C9）物质，以及所选物种之间的线性关系（包括∑C2-C4和∑C8-C12）和无机标记物（K+和SO 42 −）这意味着二元酸及其相关化合物主要来源于煤燃烧和生物质燃烧排放，并通过原位光化学反应在大气中产生在夏季和冬季的长距离运输过程中，局部规模的反应和老化。研究表明，随着SO 42-的增加，土壤中的二元酸及其相关化合物和水溶性有机碳含量增加，且它们都是在水相中产生的，这意味着减少NOx和SO2的排放可能会控制华北地区水溶性有机碳的负荷。
To understand the characteristics and sources of organic aerosols (OA) in North China, we studied diacids, oxoacids, andα‐dicarbonyls in summer‐ and winter‐time fine aerosols (PM2.5) collected from Tianjin. Oxalic (C2) acid was found to be the most abundant diacid species, followed by succinic (C4), malonic (C3), and sebacic (C8) acids, respectively. Glyoxylic (ωC2) was the most abundant oxoacids followed by pyruvic acid. Concentrations of total diacids, oxoacids, andα‐dicarbonyls in winter were 2–3 times higher than those in summer, but their mass fractions in PM2.5were exactly the opposite. On average, total diacids carbon accounted for 2.9% in total carbon and 3.3% in organic carbon (OC) in summer and 1.8% and 2.0%, respectively, in winter. Their contributions to water‐soluble OC (WSOC) was almost the same in both seasons (5.5% and 5.3%, respectively). Molecular distributions, mass ratios of selected diacid (C3, C4, M, F, C6, Ph, and C9) species, and the linear relations among the selected species (including ∑C2–C4and ∑C8–C12) and with inorganic markers (K+and SO42−) implied that the diacids and related compounds are mainly originated from coal combustion and biomass burning emissions and produced in the atmosphere by both in situ photochemical reactions at local scale and aging during long‐range transport in both summer and winter. This study revealed that diacids and related compounds and WSOC are increased with increasing SO42−and they are produced in the aqueous phase, implying that the reduction in NOxand SO2emissions could possibly control the water‐soluble OA loading over North China.