The Complex Resistivity Detection Technology For Chrome-Contaminated Site

The complex resistivity method is chosen as the heavy metal contaminated sites detection method on the basis of experimental study of the soil electrical parameters changes caused by the changes of soil physical parameters. The electrical parameters include resistivity, complex resistivity, dielectric constant and magnetic susceptibility.Cole-Cole model is selected as the circuit model for the soil complex resistivity. We derive the relation between the Cole-Cole model parameters and soil physical model parameters in the micro-structure. Based on the mean spherical approximation theory, combined with Archie's equation, the DC resistivity is getted which is the leading role of electrical conductivity in the soil complex resistivity model. Double-layer capacitance parameter which has capacitance characteristics in the soil complex resistivity model is obtained on the basis of Double-clay-plate model and Poisson-Boltzmann equation.The soil complex resistivity parameters include some ones which is related to soil itself characteristics. The specific soil parameters are obtained on the basis of a large number of experimental data through the inversion algorithm. A one-dimensional digital filtering program is designed to verify the site numerical model based on the finite element method, and the results show that the the finite element numerical simulation combined with equivalent resistivity method is correct. The apparent complex resistivity datas getted by measuring the established site model are used to inversed step by step for the soil physical model, and the comparison show that inversion results can bring a better distinction for the moisture and pollution.