摘要
运用X射线粉末衍射、红外光谱、扫描电镜、激光粒度仪和硫同位素分析等方法对西安市11个采样点大气降尘中石膏等矿物进行研究,表明石膏矿物是在大气环境中形成.西安市大气降尘中石膏含量范围0～20%,平均6.3%, 多为μm级自形微晶.降尘中硫同位素组成与其硫含量负相关;同时,降尘硫含量(平均SO2含量6%)远远高于源区物质(平均0.94%),说明其主要来自大气气相硫.结合降尘微形貌特征与SO2含量的关系分析,降尘中的SO2含量不仅受粒度控制,还与大气降尘的种类和性质有关.降尘对空气中SO2的'捕捉作用' 具有不均匀性,可以影响和改变城市大气中S元素的分布、传输路径和沉积方式.加强对大气降尘环境矿物学研究, 查清大气降尘矿物成分及其组合的时空变化,对探索含硫污染物的演化轨迹和评价含硫污染物的环境危害性具有重要意义.
Study and analysis of the composition of atmospheric particles by means of XFR, XRD,SEM, analysis of grain size and sulfur isotopic composition indicated that gypsum in the samples taken from 11 spots in Xi＇ an city was formed in the atmospheric environment. The gypsum contents are range from 0% to 20%, averaging 6.3%. Gypsum crystals are mostly composed of automorphic μm-sized microlite. That sulfur isotopic composition is negatively correlated with the sulfur contents in atmospheric particles, and the sulfur contents （SO2 6% ） in atmosphere are higher than those （0.94%） in their source indicated that the sulfur in atmospheric particles came from gaseous sulfur. According to the relationship between the micromorphology and the SO2 contents of particulates, it can be concluded that SO2 contents in particulates are not only controlled by grain size, but also by the type and property of dust. It may affect and change SO2 distribution,delivering path and sedimentation in urban atmosphere that captured SO2 captured in atmosphere has an asymmetric idiosyncrasy, Therefore, study on the environmental mineralogy of atmospheric pa.ttieulates should be strengthened so that spatio-temporal variability can be found out. Study on environmental mineralogy is of important significance fin reve, aling the evolution path of sulfur-beating pollutants and estimating harm grade to the environment,
出处
《矿物学报》
CAS
CSCD
北大核心
2005年第2期135-140,共6页
Acta Mineralogica Sinica
基金
陕西省教育厅基金项目(2002JC10)
关键词
大气降尘
气相硫
石膏
环境矿物学
atmospheric particulate
gaseous sulfur
gypsum
environmental mineralogy
