Avaliação da qualidade das águas utilizando índices ambientais e um estudo de metais em águas, sedimentos e macrófitas no Lago do Amor

Abstract

In this study was evaluated the water quality indexes in the Lake of Amor in Campo Grande – MS City. The Water Quality Index, adapted by Environmental Sanitation Company (Cetesb) of the São Paulo State and Trophic State Index were used. The Water Quality Index uses Dissolved Oxygen, Fecal Coliforms, pH, Biochemical Oxygen Demand, Total Nitrogen, Total Phosphorus, Temperature, Total Solids and Turbidity parameters. The Trophic State Index uses Total Phosphorus and Transparence parameters. Metal concentrations in waters, in sediments and in macrophytes were considered. In case of water samples, an alpha vertical sampler was used and “Core” Sampler applied to sediments. The metals analyzed were: Aluminum, Barium, Cadmium, Lead, Copper, Chromium, Iron, Manganese, Mercury, Nickel and Zinc. The Water Quality Index shows results varying of GOOD to BAD in the analyzed points. The Trophic State Index indicated EUTROPHIC, MESOTROPHIC e HIPERTROPHIC conditions. The parameters in bad agreement with Conama no 357/05 Resolution were: Fecal Coliforms, Total Coliforms, Total Phosphorus, Dissolved Oxygen, Color and Turbidity, In waters, the metals in bad agreement with this resolution were: Cadmium, Lead, Manganese, Mercury, Nickel and Zinc. In relation to sediment profiles, the metals in bad agreement with Conama no 344/04 Resolution were: Cadmium, Lead, Copper, Mercury, Nickel and Zinc. In case of macrophytes the analyses shown that the metals Aluminum, Barium, Cadmium, Lead, Copper, Chromium, Iron, Manganese, Mercury, Nickel and Zinc present concentrations higher in the roots than in the stalks and leaves.