Chemical Characterization and Source Apportionment of PM2.5 during Spring and Winter in the Yangtze River Delta, China
Chemical Characterization and Source Apportionment of PM2.5 during Spring and Winter in the Yangtze River Delta, China
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中国长三角地区春冬季PM2.5化学特征及来源解析
DOI：
10.4209/aaqr.2017.03.0108
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发表时间：
2017-09-01
影响因子：
4
通讯作者：
Xiao, Hang
中科院分区：
文献类型：
--
作者：
Du, Wenjiao;Zhang, Yanru;Xiao, Hang
为了解长三角地区PM2.5的特征和来源，在上海、南京、宁波三个主要城市和区域背景城市临安选择了10个采样点，在春冬季采集了380个样品。分析了PM2.5质量浓度和化学组分的时空特征。同时，综合利用大气质量簇和正矩阵分解(PMF)源分配模型识别PM2.5的来源。冬季PM2.5m~(-3)质量浓度(83.51~107.64µg·m~(-3))高于春季(54.11~85.72m~(-3))。长三角地区PM2.5以硫酸盐、硝酸盐和铵(SNA)为主，春季占39.0%，冬季占46.1%。由于有机前体排放的增加，次生有机碳(SOC)与有机碳(OC)的比值在冬季普遍较高。冬季AE/CE平均当量比为0.81+/-0.25，春季平均当量比为0.96+/-0.33，表明长三角地区大气颗粒物呈轻度碱性。二次气溶胶(29.44%)和交通(25.66%)是长三角春季PM2.5的主要来源，冬季次生气溶胶和交通分别占22.71%和29.71%。此外，来自中国北部的气团气流在春季为长三角地区输入了大量的逃逸土壤，并通过远距离输送增强了冬季燃烧的贡献，而来自中国西南部的气团与生物质燃烧有很强的相关性。结果表明，大气质量输送对长三角地区PM2.5浓度和化学特征有显著影响。
To investigate the characteristics and sources of PM2.5 in the Yangtze River Delta (YRD) region, a total of 10 sampling sites were selected in the three major cities of Shanghai, Nanjing, and Ningbo and the regional background city of Lin'an, and 380 samples were collected in spring and winter. The spatiotemporal characteristics of the PM2.5 mass concentration and the chemical components were analyzed. Meanwhile, air mass clusters and the positive matrix factorization (PMF) source apportion model were comprehensively used to identify the sources of PM2.5. The mass concentration of PM2.5 in winter (83.51-107.64 mu g m(-3)) was higher than that in spring (54.11-85.72 mu g m(-3)). Sulfate, nitrate, and ammonium (SNA) dominated the PM2.5, accounting for 39.0% in spring and 46.1% in winter in the YRD region. Higher ratio of secondary organic carbon (SOC) to organic carbon (OC) generally occurred in winter due to increased emissions of organic precursors. The mean equivalent ratio of AE/CE was 0.81 +/- 0.25 in winter and 0.96 +/- 0.33 in spring, which indicated a slight alkalinity of the atmospheric particles in the YRD region. Secondary aerosols (29.44%) and traffic (25.66%) were identified as the main sources of PM2.5 in the YRD during spring, and they contributed 22.71% and 29.71% in winter. In addition, air mass flow from Northern China imported substantial fugitive soils to the YRD region in spring and enhanced the contribution of combustion in winter through long-range transport, while air masses originating from Southwestern China were strongly associated with biomass burning. Our results showed that the PM2.5 concentration and chemical characterization in the YRD region was significantly influenced by air mass transport.