我国不同矿物气溶胶源区物质的物理化学特征

Physical and Chemical Characters of Materials from Several Mineral Aerosol Sources in China

在我国不同的矿物气溶胶源区进行采样分析的结果表明 ,源区气溶胶物质的物理化学特性相差很大 .黄土的颗粒最细 ,91 %的黄土颗粒可以形成矿物气溶胶进行长距离输送 ;沙土较粗 ,只有 1 5 %的沙尘颗粒可以形成矿物气溶胶 ;2个煤灰样品的粒径差异较大 ,抚顺煤灰中 <74μm的颗粒高达 3 9% ,而呼和浩特煤灰只有 7% .不同粒径颗粒的化学分析结果表明 ,微量元素在细颗粒上有较高的富集 .黄土与沙漠土壤的细颗粒的化学性质十分相似 ,同煤灰的化学性质完全不同 ,其常量元素与Al的比值 (E/Al)十分接近 ,而且与深海沉积物粘土中的比值(E/Al)一致 。

Loess, sand and coal ash samples were collected at several mineral aerosol sources to analyze the particle size as well as the major and trace elements. The results show that the physical and chemical characters were quite different between these samples. The Loess was mainly made up of small particle size that 91% of the sample could be transported as mineral aerosol to a long distance. The sand consists of relative large size particles, with only 15% sample being formed into mineral aerosol. The coal ash samples were quite different in particle sizes in the two regions, with 39% of particles <74μm in Fushun samples while only 7% in Huhehaote samples. Chemical compositions varied significantly in different particle sizes, with trace elements obviously enriched in the least size. The elements to Al ratios (E/Al) were quite alike between the Loess and the sand, but very different from the coal ash. The similarity of the E/Al ratios between the Loess, the sand and the deep sea clay suggest that the deserts and the Loess in the northwest China may be important sources for sediment of the northwest Pacific Ocean.