Análise multielementar de sedimentos do córrego liso e implicações ambientais

Abstract

The sediments can provide important data on the environmental quality of aquatic environments, so the present work carried out a multielementary analysis of sediment metals from the Liso Stream, located in the city of Uberlândia-MG. CONAMA Resolution 454/12 establishes minimum and maximum values for the evaluation of the dredged material, in relation to the concentration of pollutants in the sediment. The lower limit represents the concentration below which adverse effects are rarely expected for organisms, while the higher limit represents the concentration above which adverse effect is often expected. The criterion for selection of sampling points was anthropic interference, with a point located near the source (Point 1), where low interference is expected, and another at the mouth of the Stream (Point 2), with high interference. The samples were passed through the opening process and the quantification of the metals was performed in an atomic emission spectrophotometer with coupled plasma induction source (ICP-OES). From the trace elements analyzed, copper and chromium, presented concentrations between levels 1 and 2 of CONAMA Resolution 454/12, with the probability of occurrence of adverse biological effects. The higher concentration of metals in the samples of the mouth in relation to the spring, may indicate antropic interference in the stream. In the first campaign, a difference of 500% (Cd), 39% (Cu), 49% (Cr), 120% (Ni) and 3.6% (Zn) was observed in the second of 56% (Cd), 26.8% (Cu), 21% (Cr), 30.7% (Ni), 23.86% (Zn). This work evidenced the current conditions in the sediment quality of the Liso Stream and showed that urbanization, industrialization and agriculture are not only polluting sources but also can influence the transport and accumulation of substances in the aquatic sediments. Because they were diffuse polluting sources, it was not possible to identify all the launches. The results obtained in conjunction with field verification of riparian forest conditions and anthropogenic pollution indicate that the current state of the environmental preservation status of the Liso is critical. The study also contributed to validate the feasibility of the sediment analysis as a parameter of environmental diagnosis of fluvial environments.