Liu Xiao-di, Meng Jing-Jing, Hou Zhan-Fang, Li Jing, Xing Ji-Zhao, Wei Ben-Jie, Zhang Er-Xun, Liu Jia-Zhen, Dong Jie
School of Environment and Planning, Liaocheng University, Liaocheng 252000, China.
State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an 710061, China.
Huan Jing Ke Xue. 2018 Sep 8;39(9):4014-4025. doi: 10.13227/j.hjkx.201801081.
To investigate seasonal variations in the chemical compositions of aerosols in Ji'nan City, PM samples were collected during summer and winter in 2015. The sampling period lasted one month during each season. PM samples were analyzed for the composition, concentration, and sources of water-soluble inorganic ions, organic carbon (OC), elemental carbon (EC), and water-soluble organic carbon (WSOC). Results showed that mass concentrations of PM in winter were about twice those in summer, and concentration levels varied between fine and excellent. The concentrations of total water-soluble inorganic ions were also higher in winter than in summer, with SO, NO, and NH being the dominant species and well correlated with each other. NH in PM mostly existed in the form of (NH)SO and NHNO in both summer and winter. There was strong secondary oxidation of SO and NO. The sulfate oxidizing rate (SOR) was higher in summer than in winter, while the nitrate oxidizing rate (NOR) showed the opposite trend. The ratio of anions to cations in both summer and winter were less than one, suggesting that PM were slightly alkaline. The ISORROPIA-Ⅱ mode showed that acidity in winter was stronger than in summer. Concentations of OC and EC were both higher in winter than in summer. The ratios of OC to EC and WSOC to OC and estimated concentrations of secondary organic carbon (SOC) showed that secondary pollution was more serious in winter than in summer. Principal component analysis(PCA)indicated that the major sources contributing to inorganic ions were secondary oxidation and biomass burning in summer, and coal combustion and secondary pollutants formed by chemical oxidation of precursors emitted from coal combustion in winter.
为研究济南市气溶胶化学成分的季节变化，于2015年夏季和冬季采集了PM样本。每个季节的采样期持续一个月。对PM样本进行了水溶性无机离子、有机碳（OC）、元素碳（EC）和水溶性有机碳（WSOC）的组成、浓度及来源分析。结果表明，冬季PM的质量浓度约为夏季的两倍，浓度水平在良和优之间变化。冬季水溶性无机离子的总浓度也高于夏季，其中SO、NO和NH为主要成分且彼此相关性良好。夏季和冬季PM中的NH大多以(NH)SO和NHNO的形式存在。SO和NO存在较强的二次氧化。硫酸盐氧化率（SOR）夏季高于冬季，而硝酸盐氧化率（NOR）则呈相反趋势。夏季和冬季的阴阳离子比均小于1，表明PM呈弱碱性。ISORROPIA - Ⅱ模型显示冬季的酸度强于夏季。冬季OC和EC的浓度均高于夏季。OC与EC、WSOC与OC的比值以及二次有机碳（SOC）的估算浓度表明，冬季的二次污染比夏季更严重。主成分分析（PCA）表明，夏季无机离子的主要来源是二次氧化和生物质燃烧，而冬季是煤炭燃烧以及煤炭燃烧排放的前驱物经化学氧化形成的二次污染物。
