National Demonstration Center for Experimental Geography Education, School of Geography and Tourism, Shaanxi Normal University, Xi'an, China.
National Demonstration Center for Experimental Geography Education, School of Geography and Tourism, Shaanxi Normal University, Xi'an, China; Key Lab of Aerosol Chemistry & Physics, State Key Lab of Loess and Quaternary Geology (SKLLQG), Key Laboratory of Aerosol Chemistry and Physics, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an, China; Center for Atmospheric Particles Studies, Carnegie Mellon University, Pittsburgh, PA, USA; Guangdong Provincial Key Laboratory of Utilization and Protection of Environmental Resource, State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry Chinese Academy of Science, Guangzhou, China.
Environ Res. 2022 Sep;212(Pt C):113388. doi: 10.1016/j.envres.2022.113388. Epub 2022 May 12.
As an important central city in western China, Xi'an has the worst atmospheric pollution record in China and many measures have been taken to improve the air quality in the past few years. In this study, PM samples were collected across four seasons from 2017 to 2018 in Xi'an. Organic carbon and elemental carbon, water soluble ions, and elements were monitored to assess the air quality. The average annual PM concentration was (134.9 ± 48.1 μg/m), with the highest concentration in winter (188.8 ± 93.2 μg/m), and lowest concentration in summer (71.2 ± 12.1 μg/m). The secondary generation of sulfate (SO) and nitrate (NO) was strong in spring, and secondary organic carbon (SOC) was formed in all seasons. The compositions of PM changed greatly during a sandstorm occurred and the Spring Festival. The sandstorm played a positive role in removing local pollutant NO, but also increased the concentration of SO, however both the concentration of SO and NO greatly increased by secondary generation during Spring Festival. Potential source analysis showed that during the sandstorm, pollutants were transported over a long distance from the northwest of China, whereas it was mainly from the local and surrounded emissions during the Spring Festival. Except Ca and geological dust (GM), the other components in PM increased significantly on the day of the Spring Festival. During sampling time in Xi'an, the positive matrix factorization (PMF) model analysis showed that PM mainly came from vehicle emission, coal combustion, and biomass burning.
作为中国西部的重要中心城市，西安的大气污染记录在中国最为严重，过去几年来已经采取了许多措施来改善空气质量。本研究于 2017 年至 2018 年在西安四个季节采集 PM 样本，监测有机碳和元素碳、水溶性离子和元素，以评估空气质量。平均年 PM 浓度为（134.9±48.1）μg/m，冬季浓度最高（188.8±93.2）μg/m，夏季浓度最低（71.2±12.1）μg/m。春季硫酸盐（SO）和硝酸盐（NO）的二次生成较强，所有季节都形成了二次有机碳（SOC）。沙尘暴和春节期间 PM 的成分变化很大。沙尘暴对去除当地污染物 NO 起到了积极作用，但也增加了 SO 的浓度，但春节期间二次生成使 SO 和 NO 的浓度都大大增加。潜在源分析表明，沙尘暴期间，污染物从中国西北部长距离输送，而春节期间主要来自当地和周围的排放。除 Ca 和地质尘埃（GM）外，PM 中的其他成分在春节当天显著增加。在西安采样期间，正矩阵因子分解（PMF）模型分析表明，PM 主要来自机动车排放、煤炭燃烧和生物质燃烧。
