Compositions, Sources, and Aging Processes of Aerosol Particles during Winter Hazes in an Inland Megacity of NW China
Compositions, Sources, and Aging Processes of Aerosol Particles during Winter Hazes in an Inland Megacity of NW China
复制标题
DOI：
10.3390/atmos13040521
复制
发表时间：
2022-03
期刊：
影响因子：
2.9
通讯作者：
P. Liu;L. Shao;Yaowei Li;Wenhua Wang;Mengyuan Zhang;Cheng‐Xue Yang;H. Niu;Xiaolei Feng;
中科院分区：
文献类型：
--
作者：
P. Liu;L. Shao;Yaowei Li;Wenhua Wang;Mengyuan Zhang;Cheng‐Xue Yang;H. Niu;Xiaolei Feng;
作为西北地区最大的内陆特大城市之一，西安经常面临严重的区域性雾霾天气，尤其是冬季。由于西安独特的盆地地形和独特的气象条件，其气溶胶成分高度复杂。在这项研究中，我们利用透射电子显微镜 (TEM) 和能量色散 X 射线光谱 (EDX) 技术，对西安某城市区域雾霾事件期间收集到的单个气溶胶颗粒的形态、大小和成分进行了表征。根据形态和化学成分，识别出六种类型的颗粒，包括有机颗粒（41.88%）、硫酸盐颗粒（32.36%）、烟灰颗粒（8.33%）、矿物颗粒（7.91%）、富钾颗粒（5.13%）和飞灰颗粒（4.49%）。这些结果表明，在采样期间，有机颗粒对雾度形成的贡献大于次级无机颗粒。粒径分布和优势表明有机颗粒和硫酸盐颗粒对雾霾中粒径的变化趋势起着主要控制作用。有机核颗粒的涂层厚度约为369 nm，硫酸盐核颗粒的涂层厚度约为322 nm，这意味着有机颗粒比硫酸盐颗粒更老化。本研究中提出的结果为理解雾霾颗粒的形成提供了进一步的见解。
As one of the largest inland megacities in Northwest (NW) China, Xi’an has been facing serious regional haze frequently, especially during winter. The composition of aerosols in Xi’an is highly complex due to its unique basinal topography and unique meteorological conditions. In this study, we characterized the morphology, size, and composition of individual aerosol particles collected during regional haze events at an urban site in Xi’an using Transmission Electron Microscopy (TEM) coupled with Energy-Dispersive X-ray Spectrometry (EDX). Six types of particles were identified based on their morphology and chemical composition, including organic (41.88%), sulfate (32.36%), soot (8.33%), mineral (7.91%), K-rich (5.13%), and fly ash particles (4.49%). These results demonstrate that the organic particles made a larger contribution to haze formation than the secondary inorganic particles during the sampling period. Size distribution and dominance suggest that organic and sulfate particles exert major control on the variation trends of particle size in haze. The coating thickness of organic-cored particles was about 369 nm and that of sulfate-cored particles was about 322 nm, implying that the organic particles were more aged than the sulfate particles. The results presented in this study provide further insights into understanding haze particle formation.