北京市铁路站场大气颗粒物的特征与来源分析

利用扫描电镜-X射线能谱(SEM-EDX)技术对北京市铁路站场采集的颗粒物的形貌和化学组分进行分析,并利用富集因子法及元素相关性对颗粒物中的各元素来源进行判别。研究结果表明,铁路站场所采集的主要是2μm以下的球形或椭球形富含S、Br、Zn元素的颗粒,富集因子及元素相关性分析显示,该颗粒物主要来源于铁路机车燃油排放。因此,确定颗粒物的排放源并以此进行控制,对于改善北京铁路站场周围的大气环境具有重要意义。

CHARACTERISTICS AND SOURCE APPORTIONMENT OF ATMOSPHERIC PARTICULATES IN AMBIENT AIR AT BEIJING RAILWAY STATIONS

Scanning Electron Microscopy-Energy Dispersive X-ray analytical methods were used to study chemical composition and size distribution characteristics of the atmospheric particulates samples collected from three different railway stations in Beijing.Enrichment factor method and correlation of the elements were also used for studying sources of the particulates.Results showed that,particles which were smaller than 2 μm were dominant in particulates samples,and S,Br and Zn were obviously enriched.Such instance was caused by combustion process of diesel-fuel.So it is important for ascertaining sources of the particulates to improve air quality at railway stations in Beijing.