北京沙尘暴的干盐湖盐渍土源——单颗粒物分析和XPS表面结构分析

 2002年3月20日北京特大沙尘暴565个单颗粒物分析结果表明,S和Cl是唯一呈现显著正相关的一对元素.同时含有S和Cl的单颗粒物检出率高达82.5%,其中S和Cl的含量还高于所有颗粒物平均值.同时含有S、Cl和Na的颗粒物检出率为62.0%,其中Na的含量更比所有颗粒物平均值高出1.4倍.PMF因子分析显示NaCl和Na2SO4是北京沙尘暴S和Cl显著相关的那些单颗粒物的主要成分.沙尘暴样品中SO₄^2-和C^l-浓度呈高度线性相关.X射线光电子谱对气溶胶表面结构分析显示,Na和S在沙尘暴颗粒物表面的百分含量比北京非沙尘暴和内蒙古地区气溶胶样品高.这些同时含有S、Cl和Na,且S和Cl显著正相关,Na相对富集的颗粒物多数来自于沙尘暴途中所经过的其表层土成分富含氯化物和硫酸盐的干盐湖盐渍土地区.证明了北京沙尘暴不仅来自于其源头沙漠,沙尘暴所经过的包括干盐湖盐渍土的大范围干旱、半干旱地区的表层土也是其主要来源.

The dried salt-lakes saline soils sources of the dust storm in Beijing -- the individual particles analysis and XPS surface structure analysis

individual particle analysis of the most dust storm on March 20, 2002 in Beijing showed that only S and Cl were the elements emerging remarkable positive correlations. Meanwhile, the inspecting rate of the particles containing S and Cl was high up to 82.5%, in which the content of S and Cl was much higher than the average value of all particles. At the same time, the inspecting rate of the particles containing S, Cl and Na was 62.0%, in which the content of Na was 1.4 times higher than average value of all particles. PMF analysis indicated that NaCl and Na2SO4 were the major components of these individual particles, correlated markedly with S and Cl of Beijing dust storm. The concentrations SO42- and Cl- in the storm sample also showed significant linear correlation. XPS analysis on surface structure of aerosols demonstrated that the concentrations of Na and S on the surface of particles in the dust storm were higher than those from Beijing non-dust storm and gas aerosol sample of Inner Mongolia area. Meanwhile, the particles contain S, Cl, and Na; S and Cl were also positively related markedly. Many particles enriched relatively with Na came from dried salt-lakes saline soils containing richly chloride and sulfate while the dust storm passed through these areas. All these proved that besides the deserts source was the major source of the dust storms in Beijing, the surface soils in large arid and semi-arid areas including those dry salt-lakes saline soils were also their major sources.