大气降尘TEM观察及其环境矿物学意义

在X射线衍射等分析研究基础上，进一步用透射电镜对半封闭室内长期沉积的大气降尘进行观察，提供了合肥地区大气降尘物相组成和各种物相形貌特征信息，揭示合肥地区大气污染物来源占第1位的是地表扬尘，以粘土矿物为标志；占第2位的是来源于大气化学次生气溶胶，主要和SO2、CO2、NOx等气态污染物排放有关，以石膏、碳酸盐和易溶盐类为标志；占第3位的是来源于汽车尾气排放的烟尘，以炭球为标志；占第4位的是来源于燃煤烟尘排放，以球形玻璃珠为特征。TEM调查不仅为合肥地区大气气溶胶颗粒成因、城市大气污染物来源和污染控制对策提供准确资料和依据，而且为确定大气颗粒物来源提供了有效研究方法和物源判别标志。

TEM investigation of atmospheric particle settlings and its significance in environmental mineralogy

Atmospheric particle settlings (APSs) are deposited from aerosols and have complex mineral components and chemical composition as well as varied origins. The TEM investigation of long_term atmospheric particle settlings can provide information concerning phase components, morphology and origins of APSs as well as their symbols. According to the investigation in Hefei area, the dust blowing from the surface with clay minerals as the symbol possesses the first importance, the autogenous aerosol related to SO 2, CO 2 and NO X with gypsum, carbonate, and other soluble salts as the symbols occupies the second importance, the dust from automobiles with nanometer carbon balls as the symbol is the third in importance, and the dust from combustion of coal with silicate microbeads as the symbol is the last in importance. The authors have also found nanometer calcite biomineralization inside bacteria and nanometer apatite at the surface of minerals due to biomineralization outside bacteria and interaction between bacteria and minerals. The TEM investigation provides not only information about origins of aerosols in Hefei area but also effective methods and symbols for determining APSs.