Soil and underground water contamination study by heavy metals in the old dump of Viçosa, MG, Brazil

Abstract

ln Brazil it still is unusual the existence of efficient selective waste collection systems. Thus, frequently, municipal solid wastes (MSW) have toxic materials such as, batteries, paints, fluorescent bubbles and chemical products. These residues release heavy metals which may contaminate the soil and groundwater in sanitary landfills. Therefore, this paper evaluates the transport of four heavy metals, zinc, copper, cadmium and plumb in the area that was used during fifteen years to dispose the MSW of the District of Viçosa, MG, Brazil. Initially, the topography of the area was obtained. Following, SPT tests were performed to determine the stratigraphy and the thickness of the residues. The flow pattern in the area was determined with piezometers installed in the boreholes. Disturbed and undisturbed soil samples were collected to determine geotechnical parameters, the soil permeability coefficient and the four metals transport parameters. A numerical study was performed to evaluate the contaminant plume movement of each metal and the numerical concentrations were compared to the ones verified in the field. ln general, the comparisons were satisfactory and allowed to conclude that the contamination of the water table by Cu, Pb, Cd e Zn in the region of Viçosa old dump is insignificant.