铬污染土壤介电性质影响因素研究

Chrome-Contaminated Soil Dielectric Characteristics & Influencing Factors

为了探讨复介电常数法在铬污染场地进行监测的可行性,通过试验比较了不同铬污染物质量分数、土壤含水率和孔隙比下的土壤介电性质的频散特性.结果表明,污染土壤复介电常数呈较为明显的随着频率升高而降低的频散特征,频率低于50 MHz时,土壤复介电常数的实部和虚部变化较为明显;随着铬污染物质量分数、含水率和孔隙比的增大,土壤复介电常数的实部和虚部均有增大的趋势.通过分析土壤复介电常数和含水率、铬污染物质量分数及孔隙比的变化关系,推导了土壤含水率与介电常数实部、铬污染物质量分数与介电常数虚部的关系模型,并能够对铬污染土壤的铬污染物质量分数及含水率进行分析评价,为介电常数法用于土壤中铬污染物质量分数的快速检测提供了有益的探索.

In order to investigate the feasibility of monitoring chrome-contaminated fields using the complex dielectric constant method,we compared the dielectric dispersion characteristics of the soil under conditions of different chromium pollution concentration,soil moisture content and void ratio.The results show that the complex dielectric constant of contaminated soil decreases obviously with increasing frequency.When the frequency is lower than 50 MHz,a significant change of the real and imaginary parts of the soil complex dielectric constant can be observed.Moreover,with increasing chrome pollutant concentration,moisture content and void ratio,both the real and imaginary parts of the soil complex dielectric constant increase.Through analysis of the relationship among soil complex dielectric constant and moisture content,chrome pollution concentration,and soil void ratio,we deduced a model for soil moisture content and the real quantity of soil dielectric constant,and a model for chrome pollutant concentration and the imaginary quantity of soil dielectric constant.Therefore,through the comparison of the real and imaginary quantities of the complex dielectric constant,we could evaluate and monitor chrome pollution.