Concentração de bário e elementos-traço nos córregos Areia e Feio em Araxá-MG

Abstract

The main economic activity that maintains high Araxá‘s Gross Domestic Product (GDP) is the mining of both phosphate and niobium. Although these activities generate economic benefits for the region and for the country, it has its environmental consequences. In the process of niobium (mineral pyrochlor) processing, the barium element, which integrates the mineral pyrochlore, is discarded and stored in the dams along with other wastes. Often the water resources as well as the soil located near the mining area can be contaminated by these wastes. The geology of the region of Araxá naturally can raise the concentrations of some elements by the action of the intemperes over hundreds of years (background). Therefore, the present work was carried out with the purpose of analyzing some physico-chemical parameters, barium concentration and trace elements, if there is influence and to what extent the mining affects the quality of the water that supplies the city of Araxá. Two campaigns were carried out to collect water and the samples were analyzed at the Water Quality Laboratory (LAQUA) of the Federal University of Uberlândia (UFU). It was verified that in some points there were nonconformities of some parameters with the Resolution of CONAMA 357/2005 and it was noticed that in the source of the Feio Stream (P1), the barium element concentration exceeded the permissible concentration of 0.7 mg/L, With values of 1.05 and 1.24 mg/L. In short, although some parameters are outside of what the current Resolution requires, it has not been possible to affirm that mining contributes directly to this fact.