银川市大气可吸入颗粒物质量浓度特征研究

Study on the Mass Concentration of Atmospheric Inhalable Particles in Yinchuan

利用银川市1983—1987年常规环境监测资料,系统分析了银川市大气可吸入颗粒物IPM的质量浓度特征。结果表明,银川市大气中PM2.5占IPM的比例,冬季采暖期明显高于春季风沙期和非采暖期;城市各功能区在春季、夏秋季和冬季,其IPM质量浓度谱均在0.58μm处出现峰值;冬季IPM中约有50%以上来自PM2.5的贡献,说明冬季燃煤采暖是细粒子的重要排放源之一,是细粒子污染最严重的季节;不同季节各功能区IPM谱分布出现多个峰值,是来自不同模态粒子相互作用的结果;春季风沙期、夏秋季非采暖期IPM的质量中值直径D均大于冬季;而冬季采暖期σg最小,说明该季节颗粒物分散程度最小。

Based on 1983-1987 conventional environment monitoring data from the city of Yinchuan of Ningxia, a systematic analysis is performed of the mass concentration characteristics of atmospheric Inhalable Particulate Matter （IPM） ,and analysis results indicate that the proportions of PM2.5 particles in the total IPM in winter heating months are considerably higher than those in spring sandstorm period and non-heating months. The IPM mass concentration spectral distribution exhibits a peak at particle diameter 0.58 μm in four seasons of a year. PM2.5 particles make 〉 50 % contribution to wintertime IPM,indicating that coal burning is the major emission source for fine particles that are responsible for the most severe contamination of the season. IPM size distribution displays multiplepeaks in different seasons for different functional blocks, which result from the interactions among differing-mode particles. In windy and sandy spring and non-heating summer and autumn the mass median diameter of IPM are greater than those in winter. The σg is however the smallest in heating winter,revealing that the divergent degree of IPM particle diameters in winter is minimum.