MALM-based induced polarization method for heavy metal pollution leakage monitoring: Methodology and modeling results

A new mise-a-la-masse (MALM) -based induced-polarization (IP) method is proposed for heavy-metal contamination monitoring, where the charged-source in a non-perfect conductor and contact measurements are leveraged to achieve higher accuracy. The MALM-based source enhances the amplitude of potential anomalies due to the bottlenecks of weak signal and limited measurement environment which commonly occur in traditional IP methods for heavy-metal contamination monitoring. The charged current intensity inside the conductor is calculated using a approximate formula, rather than only following a current source applied in conventional MALM method. Next, the numerical modeling is based on the discreted charged-sources and on the staggered tetrahedral meshes under the finite-element (FE) framework. An improved resistivity computation algorithm is proposed for the MALM-IP measurements. It is concluded that numerical results for the proposed technique are consistent with the model parameter variations. Moreover, a soil box experiment is consistent with the modelling results and confirms the viability of the proposed MALM-IP method. Verification of this technology is also based on comparisons of numerical modeling and soil box experiment results with those of traditional IP methods, and shows the superiority of this proposed MALM-IP method for heavy-metal contamination monitoring.