Environmental characterization of an industrially contaminated area by tetrachloroethylene using the resistive-capacitive method

Investigating soil and water contamination is essential for assessing environmental risks and monitoring remediation processes. This study, located in São Paulo, Brazil, highlights the presence of chlorinated solvents, especially tetrachloroethylene, with the application of remediation measures such as chemical oxidation. Both contamination and remediation processes have led to changes in geophysical signatures, enabling the use of electrical resistivity, despite challenges in urban areas due to consolidated infrastructure. The objective is to integrate data from direct methods and surveys of electrical resistivity and induced polarization, obtained through direct current and resistive capacitive methods, to refine the conceptual model of the area, delineating the influence zone of the contaminant and remediation processes. The resistive capacitive method allows continuous data acquisition in large areas without the need for electrode insertion into the soil. Geoelectrical data, correlated with soil sample descriptions, allow analysis of subsurface characteristics and areas affected by contamination. Variations in resistivity identify differences between lithologies, while induced polarization highlights clayey areas. Chemical oxidation to remediate PCE contamination increases conductivity, allowing for delineation of the remediation's influence zone. Despite urban challenges, the electrical resistivity method helps fill data gaps and improve the conceptual model of the area, demonstrating a rapid and effective approach.