裸土起尘颗粒物中Cd^(2+)与矿物赋存特性

Study on Occurrence Characteristics of Cd^(2+) and Mineral in Dust Particles of Bare Soil

为探索裸土起尘后悬浮颗粒物对Cd^(2+)的携带特性与其矿物组成、粒径尺寸的关联,通过对土壤样品进行Cd^(2+)污染预处理,在构建的"阳离子型污染物土壤表层运移行为研究系统"内模拟风速条件下进行起尘试验,对土壤经风吹起尘后的吹前表层土、吹后地表土、吹后表层土、总悬浮颗粒物(TSP)及各级粒径悬浮颗粒物中Cd^(2+)的赋存状态及其矿物组成与含量进行分析,并进一步对土壤中黏粒进行提取分析。结果表明:土壤起尘过程是对Cd^(2+)的一种高于本底浓度的迁移过程;起尘颗粒物中Cd^(2+)浓度随着颗粒物粒径的减小而增加,呈现负相关;Cd^(2+)的浓度与黏土矿物(伊利石+绿泥石)含量在不同粒径的颗粒物上变化规律具有一致性。

To explore the correlation between the carrying characteristics of the suspended particles and the mineral composition and the size of the particles,with the soil samples polluted by cadmium,the dusty experiment was carried out under the simulated wind power in the soil surface transport behavior research system of cationic pollutants.The occurrence state of Cd2+,mineral composition and content which were in suspended particles formed by wind blows the bare soil,ground dustfall,residual particles on bare soil surface,total suspended particulates(TSP)and different size suspended particles were analyzed.Further,the clay in the soil was extracted and analyzed.The results showed that the soil dusting process was a transport process of cadmium above background concentration.In addition,the concentration of cadmium in particulate matter increases with the decrease of particle size,which showed a negative correlation.The concentration of cadmium was consistent with the change of clay mineral(illite and chlorite)content on the particle with different sizes.