Identification of clay minerals in a landfill soil in the northwestern region in the state of Rio Grande do sul, Brazil

Abstract

Soil plays a key role in maintaining life on the planet. However, over the years, its support capacity has been reduced, mainly due to the release of contaminants. Thus, research evaluating the medium’s support of the operation of certain activities is of paramount importance. This study aims to identify the clay minerals present in a landfill soil, located in Seberi, northwest of the Rio Grande do Sul State, Brazil. For this, samples were collected in three profiles, in two horizons. For the identification of the clay minerals, the clay fraction was separated and analyzed with the aid of the X - Ray Diffraction technique. The results indicated that the soil was classified as very clayey, the predominance of the clay mineral kaolinite (typical of weathered soils), low activity and low CEC. Thus, the soil in the area has limited capacity of cations retention, resulting from a possible contamination of the landfill operation, result of low CEC. On the other hand, the kaolinite, which is a no expansive clay mineral, presents low dispersion of water in the soil profile, reducing the percolation of water and consequently contamination of the temporary suspended aquifer. Thus, the soil presents a low permeability, through its clayey characteristic and the present clay minerals.