Simultaneous measurements of urban and rural particles in Beijing - Part 1: Chemical composition and mixing state
Simultaneous measurements of urban and rural particles in Beijing - Part 1: Chemical composition and mixing state
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DOI：
10.5194/acp-20-9231-2020
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发表时间：
2020-08-05
影响因子：
6.3
通讯作者：
Yang, Fumo
中科院分区：
文献类型：
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作者：
Chen, Yang;Cai, Jing;Yang, Fumo
2016 年 11 月 1 日至 29 日，在北京的一个城市和一个农村地点同时部署了两台单颗粒气溶胶质谱仪 (SPAMS)，以调查北京空气颗粒物的来源和过程。在本研究的第一部分中，我们报告了两个地点的单颗粒化学成分、混合状态和演化。在城市和农村地点，收集到的颗粒物中碳质含量分别为 96% 和 98%。在两个地点都观察到了五种颗粒类别，包括元素碳 (EC)、有机碳 (OC)、内部混合 EC 和 OC (ECOC)、富钾 (K-rich) 和金属。根据不同的大气处理阶段，这些类别被划分为颗粒类型。两个站点共有 17 种颗粒类型。城区内，EC-Nit（Nit：硝酸盐）、ECOC-Nit等含硝酸盐颗粒类型在夜间尤为富集，含硫酸盐颗粒物在风速较大时被输送，ECOC-Nit-Sul（Sul：硫酸盐）多在局部老化。总而言之，城市地区这些经过处理的颗粒物总计达85.3%。在农村地区，区域颗粒物丰富，但新排放的 ECOC 和 OC 具有不同的模式，在烹饪和加热时间很明显。生物质燃烧、交通和煤炭燃烧是农村和城市地区颗粒物（PM2.5）的主要来源。此外，还发现了来自南部钢铁工业的颗粒物。综上所述，北京市城乡颗粒物类型化学成分相似；城市颗粒物受到农村加工和运输的显着影响。这项工作有助于了解北京冬季城乡颗粒物的演变。
Two single-particle aerosol mass spectrometers (SPAMSs) were deployed simultaneously at an urban and a rural site in Beijing during an intensive field campaign from 1 to 29 November 2016 to investigate the source and process of airborne particles in Beijing. In the first part of this research, we report the single-particle chemical composition, mixing state, and evolution at both sites. A total of 96 % and 98 % of collected particles were carbonaceous at the urban and rural sites, respectively. Five particle categories, including elemental carbon (EC), organic carbon (OC), internal-mixed EC and OC (ECOC), potassium-rich (K-rich), and metals, were observed at both sites. The categories were partitioned into particle types depending on different atmospheric processing stages. A total of 17 particle types were shared at both sites. In the urban area, nitrate-containing particle types, such as EC-Nit (Nit: nitrate) and ECOC-Nit, were enriched especially at night, sulfate-containing particles were transported when wind speed was high, and ECOC-Nit-Sul (Sul: sulfate) were mostly aged locally. In sum, these processed particles added up to 85.3 % in the urban areas. In the rural area, regional particles were abundant, but freshly emitted ECOC and OC had distinct patterns that were pronounced at cooking and heating times. Biomass burning, traffic, and coal burning were major sources of particulate matter (PM2.5) in both rural and urban areas. Moreover, particles from the steel industry located in the south were also identified. In summary, the chemical composition of urban and rural particle types was similar in Beijing; the urban particles were influenced significantly by rural processing and transport. The work is useful to understand the evolution of urban and rural particles in Beijing during winter.