兰州市城区与背景点冬季大气气溶胶中主要无机离子的组成特征

THE COMPOSITION CHARACTERISTICS OF MAIN INORGANIC IONS IN ATMOSPHERIC AEROSOL OF THE URBAN AND ATMOSPHERIC BACKGROUND IN LANZHOU CITY IN WINTER

对冬季兰州市城区和环境背景观测点的大气气溶胶样品进行了综合分析.结果显示,在同一地区的气溶胶中,细颗粒(PM10)所富集的无机离子浓度要比粗颗粒(TSP)高出7.59%—15.3%.说明水溶性离子更易在细颗粒中富集.气溶胶在受到人为污染影响后,其水溶性离子的浓度和构成也会因此发生变化.我们可以用测定同一区域内不同采样点气溶胶水溶物浓度的方法,来判断该地区大气气溶胶受污染的程度.在城区集中燃放烟花爆竹的除夕夜,气溶胶中部分水溶性离子浓度会迅速上升.上升幅度最大的是K+,与非燃放期相比,TSP和PM10中K+分别高出10.70倍和11.5倍.其次是NO3-,SO42-,Mg2+,NH4+和Cl-离子.

The samples of atmospheric aerosol were synchronous and consecutive collected 34 days in the plateau inland city of Lanzhou and the observation points of atmospheric background in winter in 2007. The eight kinds of watersoluble inorganic anion （F^-, Cl^-, NO2^-, Br^-, NOr, PO4^3-, SO^2-, SO4^2- ） and six kinds of water-soluble inorganic cation （Li^＋ , Na^＋ , NH4^＋ , K^＋ , Mg^2＋ , Ca^2＋ ） in the sample were comprehensive analyzed and studied. The samples of aerosol synchronization collected showed that the concentration of inorganic ions accumulated in the fine aerosol particles（PM10） was 7. 59% to 15.3% higher than in the coarse particles（TSP）. It showed the more water-soluble ions accumulated in fine particles. The composition and concentration of water-solluble ions will change in the anthropogenic pollution and impact of aerosols , we can initial judge that the the level of pollution of atmospheric aerosols by the determination method of water-souble matter in aerosol in the same region and different sampling point. The concentrations of partial water-soluble ions in atmospheric aerosol will be growing rapidly on new yearg eve , The largest increase ions is K ^＋ , higher than in the non-discharge period increased by 10. 70 times and 11.5 times, followed by NO3^- , SO4^2- , Mg^2＋, NH4^＋ , and Cl^-.