Monitoring Heavy Metal Transport in Aquifer Based on Electrical Property Measurements

Monitoring the movement of subsurface contamination using the electrical properties of soils has the economical merits of providing continuous and automated soil profiles. However, identification on the sensitivity of this property in reflecting both the presence and concentration of different contaminant types has been validated for soils under static conditions. For application, electrical properties of soils must be verified under an active state where contaminant migration by means of groundwater migration is considered. The objective of this study is to provide the groundwork required in applying the electrical properties of soil as a means of monitoring contaminant migration by performing column tests. Two parameters representing the electrical property of materials are examined in this study; the electrical resistivity and the dielectric constant. Measurements for these parameters are performed at a low frequency range where the spatial polarization takes place and increases the sensitivity of the electrical property against the presence of the contaminant. In order to detect the contaminant movement in the subsurface level, electrical measurements were performed during column tests for saturated sand and weathered granite soil. In addition, three different contaminants (aluminum, lead, and cadmium) were selected to groundwater contaminated by heavy metals. As a result, the relationships between the contaminant migration against the electrical resistivity, real, and imaginary parts of the dielectric constant were derived for different time intervals during the column tests.