北京城区和远郊区大气细颗粒PM_(2.5)元素特征对比分析

为了对比大气悬浮颗粒PM2.5及其所含元素在北京城区与远郊区的特征,在2007年不同季节和2008年北京奥运会期间进行了PM2.5的采样分析。结果表明:城区PM2.5和元素的浓度均高于郊区,元素浓度在城区与郊区具有不同的季节变化特征,春、冬季地壳元素浓度在城区与郊区都有所增加,在城区S元素和其它污染元素在秋、冬季最高,而郊区S元素浓度在夏季最高。污染元素的富集程度夏秋季高于春冬季,郊区高于城区,城、郊两地PM2.5中元素来源相似。雾霾天PM2.5及元素浓度在城区增加明显,奥运期间污染元素的质量分数较奥运前明显降低。

Comparison of Elemental Characteristics of Suspended Particles PM2.5 in Urban and Rural Area of Beijing

To investigate the difference in elemental characteristics of PM2.5 in urban and rural area of Beijing,the sampling of PM2.5 and element analysis were carried out in four seasons of 2007 and during the Beijing 2008 Olympic Games.The results showed that the concentrations of PM2.5 and elements were higher in urban area than that in rural area.The different seasonal variations of elemental concentration were observed in urban and rural area.The concentration of crustal elements increased in both urban and rural areas during spring and winter season.In urban area,concentrations of S and other pollutant elements were highest during autumn and winter.In rural area,the concentration of S element was highest in summer.The enrichment factor of pollutant elements was higher in summer and autumn than that in spring and winter,and was higher in rural area than that in urban area.The origin of elements in PM2.5 in urban area was similar with that in rural area.The concentrations of PM2.5 and elements increased evidently in urban area during fog and haze days.The percentage of pollutant elements decreased during the Beijing 2008 Olympic Games.