Lei Yali, Shen Zhenxing, Tang Zhuoyue, Zhang Qian, Sun Jian, Ma Yongjing, Wu Xiaoyan, Qin Yiming, Xu Hongmei, Zhang Renjian
Department of Environmental Sciences and Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi, China.
School of Environmental & Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an, Shaanxi, China.
PeerJ. 2020 Feb 14;8:e8447. doi: 10.7717/peerj.8447. eCollection 2020.
Daily PMand PM sampling was conducted during four seasons from December 2013 to October 2014 at three monitoring sites over Yulin, a desert margin city. PM and PM levels, water soluble ions, organic carbon (OC), and elemental carbon (EC) were also analyzed to characterize their chemical profiles. (light extinction coefficient) was calculated, which showed the highest in winter with an average of 232.95 ± 154.88 Mm, followed by autumn, summer, spring. Light extinction source apportionment results investigated (NH)SO and NHNO played key roles in the light extinction under high RH conditions during summer and winter. Sulfate, nitrate and Ca dominated in PM/PM ions. Ion balance results illustrated that PM samples were alkaline, and PM samples were more alkaline than PM. High SO /K and Cl/K ratio indicated the important contribution of coal combustion, which was consistent with the OC/EC regression equation intercepts results. Principal component analysis (PCA) analyses results showed that the fugitive dust was the most major source of PM, followed by coal combustion & gasoline vehicle emissions, secondary formation and diesel vehicle emissions. Potential contribution source function (PSCF) results suggested that local emissions, as well as certain regional transport from northwesterly and southerly areas contributed to PM loadings during the whole year. Local government should take some measures to reduce the PM levels.
2013年12月至2014年10月的四个季节里，在沙漠边缘城市榆林的三个监测点进行了每日PM和PM采样。还分析了PM和PM水平、水溶性离子、有机碳（OC）和元素碳（EC），以表征其化学特征。计算了（消光系数），结果显示冬季最高，平均为232.95±154.88Mm，其次是秋季、夏季、春季。消光源分配结果表明，（NH）SO和NHNO在夏季和冬季高湿度条件下的消光中起关键作用。硫酸盐、硝酸盐和Ca在PM/PM离子中占主导地位。离子平衡结果表明，PM样品呈碱性，PM样品比PM更碱性。高SO/K和Cl/K比值表明煤炭燃烧的重要贡献，这与OC/EC回归方程截距结果一致。主成分分析（PCA）结果表明，扬尘是PM的最主要来源，其次是煤炭燃烧和汽油车排放、二次形成和柴油车排放。潜在贡献源函数（PSCF）结果表明，全年本地排放以及来自西北和南部地区的某些区域传输对PM负荷有贡献。当地政府应采取一些措施降低PM水平。
