北京市中关村地区大气降尘的来源与垂向分布特征

Sources and perpendicular distribution of atmospheric particles in Zhongguancun area of Beijing

利用光学和电子显微镜、X射线衍射仪以及同步辐射X射线荧光对北京市中关村地区大气降尘的粒度分布、颗粒物微观形貌特征、矿物组成及化学元素组成等方面进行分析研究。粒度分析表明中关村地区大气降尘随着相对高度的增加,粗颗粒物逐渐减少。大气降尘的颗粒物形貌可以分为粒状、柱状单矿物,圆球状飘珠和不规则粒状集合体3种类型。矿物组成及化学元素组成的分析显示中关村地区大气降尘的污染物主要来自自然扬尘、建筑扬尘、燃煤、汽车尾气等污染源。

Particle distribution, morphology, mineral and chemical compositions of atmospheric particles were studied by optic and electronic microscopy, X-ray diffraction and synchrotron radiation X-ray fluorescence. Statistical results demonstrate that the coarse particles of atmospheric particles in Zhongguancun area decrease with the elevation of the relative height. There are three morphologi- cal types, namely, grained and columnar individual minerals, spherical flying beads and irregular aggregates. Other analytical results show that atmospheric particles come mainly from natural dust, concrete industry, coal-fire, and automobile exhaust pollution.