Zhao Qing, Li Xing-Ru, Wang Guo-Xuan, Zhang Lan, Yang Yang, Liu Shui-Qiao, Sun Ning-Ning, Huang Yu, Lei Wen-Kai, Liu Xin-Gang
College of Resource Environment and Tourism, Capital Normal University, Beijing 100048, China.
Department of Chemistry, Capital Normal University, Beijing 100048, China.
Huan Jing Ke Xue. 2021 Apr 8;42(4):1626-1635. doi: 10.13227/j.hjkx.202008304.
In order to reveal the chemical composition characteristics and pollution sources of fine particulate matter (PM) in autumn and winter in Yuncheng, PM samples were continuously collected using a four-channel small-flow particulate sampler from October 15, 2018 to March 15, 2019. The study prediminantly analyzed the chemical components of water-soluble ions, elemental carbon, organic carbon, and metal elements. Additionally, the chemical mass reconstruction method of particulate matter and the positive matrix factorization model (PMF) were combined for an in-depth discussion. During the sample period, the PM mass concentrations range was 29.37-370.11 μg·m, and 101 days during the sampling period exhibited concentrations that were higher than the secondary standard in China's Ambient Air Quality Standards (GB 3095-2012), with an exceeding rate of 70.63%. These results indicate that the air pollution in Yuncheng in autumn and winter is serious. According to the air quality index (AQI), the collected samples are classified as clean, light-moderate pollution, and heavy-severe pollution. Water-soluble ions, OC, EC and metal elements account for 40%, 19%, 5%, and 7% on clean days, 46%, 18%, 4%, and 5% on days with light-moderate pollution, and 46%, 21%, 4%, and 4% on days with heavy-severe pollution, respectively. Secondary ions NO, SO, and NH are the primary components of water-soluble ions, accounting for 81% (clean days), 87% (light-moderate pollution), and 87% (heavy-severe pollution) of the total ion concentration, respectively. The OC/EC ratios during the sampling period were 3.78 (clean days), 4.02 (light-moderate pollution), and 5.37 (heavy-severe pollution). With the intensification of pollution, the pollution of secondary organic aerosols in the atmosphere becomes increasingly serious. In addition, as the air pollution increased, the concentration of Fe and Cr elements gradually decreased, while the concentration of other metal elements showed an overall upward trend. The results of the chemical mass reconstruction demonstrate that among the different pollution levels of atmospheric PM in Yuncheng, the mass percentages of secondary inorganic salt, sea salt, heavy metals, mineral dust, construction dust, organic matter, and elemental carbon were 36%, 2%, 2%, 8%, 1%, 33%, and 5% (clean days), 41%, 1%, 1%, 5%, 0.01%, 31%, and 5% (light-moderate pollution), and 41%, 1%, 1%, 4%, 0.004%, 34%, and 4% (heavy-severe pollution). The proportion of secondary inorganic ions increased and mineral dust decreased with the deterioration of air quality. The PMF analysis results suggest that secondary related sources, coal combustion sources, vehicle exhaust sources, biomass burning, and secondary organic matter are the predominant sources of PM during serious air pollution in Yuncheng.
为揭示运城市秋冬季细颗粒物（PM）的化学组成特征及污染来源，于2018年10月15日至2019年3月15日，使用四通道小流量颗粒物采样器连续采集PM样本。该研究主要分析了水溶性离子、元素碳、有机碳和金属元素的化学成分。此外，结合颗粒物化学质量重构方法和正矩阵因子分解模型（PMF）进行深入探讨。采样期间，PM质量浓度范围为29.37 - 370.11μg·m，采样期内有101天的浓度高于中国《环境空气质量标准》（GB 3095 - 2012）中的二级标准，超标率为70.63%。这些结果表明运城市秋冬季空气污染严重。根据空气质量指数（AQI），将采集的样本分为清洁、轻度 - 中度污染和重度 - 严重污染。清洁日水溶性离子、有机碳、元素碳和金属元素分别占40%、19%、5%和7%，轻度 - 中度污染日分别占46%、18%、4%和5%，重度 - 严重污染日分别占46%、21%、4%和4%。二次离子NO₃⁻、SO₄²⁻和NH₄⁺是水溶性离子的主要成分，分别占总离子浓度的81%（清洁日）、87%（轻度 - 中度污染）和87%（重度 - 严重污染）。采样期间OC/EC比值分别为3.78（清洁日）、4.02（轻度 - 中度污染）和5.37（重度 - 严重污染）。随着污染加剧，大气中二次有机气溶胶污染日益严重。此外，随着空气污染加剧，Fe和Cr元素浓度逐渐降低，而其他金属元素浓度总体呈上升趋势。化学质量重构结果表明，在运城市大气PM不同污染水平下，二次无机盐、海盐、重金属、矿物粉尘、建筑扬尘、有机物和元素碳的质量百分比分别为36%、2%、2%、8%、1%、33%和5%（清洁日），41%、1%、1%、5%、0.01%、31%和5%（轻度 - 中度污染），41%、1%、1%、4%、0.004%、34%和4%（重度 - 严重污染）。随着空气质量恶化，二次无机离子比例增加，矿物粉尘比例降低。PMF分析结果表明，二次相关源、燃煤源、机动车尾气源、生物质燃烧和二次有机物是运城市严重空气污染期间PM的主要来源。
