Análise da qualidade da água da bacia hidrográfica do Rio Dourados por parâmetros físico-químicos e metais

Abstract

The importance of a river goes beyond its use as a source of drinking water. It plays an important role in shaping the landscape, molding the physical environment around it with its curves and levels that delimit the topography, as complex and dynamic ecosystems that are essential for environmental balance. However, anthropogenic pollution is one of the main threats to these ecosystems. The objective of this study was to evaluate the water quality of the Dourados river basin, through physicochemical parameters and metal concentrations, and to verify if there is correlation of land use and coverage with the analyzed variables. The study period comprised 6 collections, carried out between February and December 2022. The following parameters were evaluated: temperature, pH, organic matter, total acidity, total alkalinity, chlorides, hardness, turbidity, total solids, as well as zinc, aluminum, lead and iron metals. In general, the average concentrations obtained for the physicochemical parameters did not exceed the limits recommended by CONAMA Resolution No. 357/2005 for Class II and III waters, except for conductivity and organic matter. The metals resulted in levels above the established limit for lead, iron and aluminum, with a high risk to the aquatic environment. Geological factors, land use and occupation, extensive areas of agriculture with intensive use of pesticides, herbicides, and fertilizers, in addition to urban pollution, explain the changes found in the analyzed parameters.