Analysis of leaks from geomembrane in a sanitary landfill through models of electrical resistivity tomography in South Brazil

摘要

Landfills are the main destination of solid waste generated in Brazil. Based on technical criteria, the construction of a landfill aims to minimize environmental impacts since it can present problems of high complexity. This paper discusses the use of electric resistivity tomography applied in a waste cell of a landfill, and its objective is to evaluate the effectiveness of such tool in the detection of possible leachate's leakage points in the landfill's geomembrane. The leachate is a liquid effluent characterized by a high content of dissolved salts produced by the decomposition of organic matter. Therefore, a signature of low electrical resistivity defines the presence of this compound in soil and groundwater. The analysis of 12 sections of electrical resistivity tomography in Schlumberger arrangement allowed the estimation of 47 Omega m as the minimum resistivity value for the natural conditions, in addition to the possibility to provide the identification of the area under the waste cell with lower resistivity values. The integration of a software that compiles 2D data into 3D viewing models enabled isosurface adjustments of 7 and 14 Omega m in resistivity maps to -4 and -10 m depth levels at the base of the landfill and the aquifer, respectively. These areas define points of infiltration in soil, by leakage at geomembrane in the bottom of the landfill. The results show the applicability of the method in the diagnosis of leachate contamination in a high-complexity environment. In addition, it is possible to establish an effective system for the remediation in a place where the installation of monitoring wells can increase the environmental impact.