Mineração de cobre e ouro na Amazônia oriental: elementos potencialmente tóxicos em uma perspectiva ambiental e qualidade de áreas em recuperação.

Abstract

Mining activity generates residues that have physical, chemical and biological variation, generally presenting characteristics such as low concentrations of nutrients and organic matter and high concentration of potentially toxic elements that restrict the establishment of ecosystems. Therefore, for the mining sector, it is a challenge to recover areas with waste deposition, considered environmental liabilities, being essential to monitor the recovery processes for the return of ecosystem services, with the establishment of evaluations changes in chemical attributes such as fertility and physical properties such as penetration resistance, it is still essential to identify levels of potentially toxic elements both in pit areas, tailings dams and mining waste piles, in order to assess environmental risks. The objective of this objective of this study was to evaluate the quality of study areas of environmental recovery from copper (Cu) and gold (Au) mining, in addition to identifying the levels of toxic elements and determining factors and in in and ecological risk of these elements. The study was carried out in mining waste deposition areas and in adjacent areas of the Cu do Sossego and Au do Igarapé Bahia and Águas Claras mines. Samples were collected and analyzed regarding their chemical and physical attributes, in addition to an environmental analysis of these areas. In the study carried out, in the areas of the copper mine, the contents of Co, Cu and Ni in the tailings area exceeded the prevention values, reference values of soil quality and average concentrations of the upper continental crust, however, the tailings area was considered non-polluted according to the pollution load index in addition to low potential ecological risk. For gold mine waste areas, EPTs levels require attention in five of the eight study areas, due to the high values of As, Cu and Mo. These same areas were signaled by the environmental indices for having evidence of contamination, yet the studied areas have both chemical, physical and fertility limitations, signaling the need for specific management to achieve success in the recovery processes, especially in areas of deposition of reject.