Determinação de metais em um lixão desativado

Abstract

The open-air disposal of Urban Solid Waste (USW), commonly known as a 'dump,' can be a potential source of risks to human health and the ecosystem. In this sense, this study aimed to evaluate the levels of heavy metals Cd, Pb, Cr, Cu, and Zn in the soil of a closed dump located in the city of Matelândia – PR. For this purpose, 5 composite soil samples were collected at a depth of 20 cm. Physical-chemical characterizations were performed using titration, flame atomic absorption spectrophotometry (FAAS), ultraviolet-visible spectrophotometry (UV-VIS), as well as pseudototal extraction of metals. The quantification of metals was carried out by Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES). It was found that, except for Cd, the other studied metals showed levels higher than the Reference Values for Soil Quality (RVSQs) established for soils in the same region. Copper (Cu) and Lead (Pb) exceeded the prevention standards established by CONAMA Resolution No. 420/2009; however, the high levels of Cu may be associated with the basaltic context of the region. Thus, it was possible to conclude that even after more than 20 years of the closure of the dump, there are still residues and possible environmental impacts associated with this persistent contamination.