Dielectric Properties Based Detection of Heavy Metal Contaminated Soil in the Frequency Range from 10MHz to 1 GHz

Physical parameters based electromagnetic methods are promising technologies to detect contaminated sites. In these methods, the dielectric property is a key parameter. In this paper, we studied the dielectric characteristics of heavy metal contaminated soil. The chromium contaminated soil was made into samples, and the open-ended coaxial line was adopted as the measurement method. Experiments were conducted in the frequency band between 10MHz and 1GHz. The results showed that the complex permittivity, including the real part and the imaginary part, changes as the ionic content changes. Especially, at low frequencies (<50MHz), the complex permittivity increases significantly with the increase of ionic content. In addition, it also could be seen that the water content of the soil also affects the complex permittivity. We proposed to adopt the drying method or the Time Domain Reflection method to determine the water content. The dielectric parameters are most affected by the ionic content after knowing the water content. Therefore, it is feasible to detect heavy metal contaminated sites based on dielectric properties.