Geochemistry in Sediment Core for Zinc and Nickel Metals and Comparison between Indexes of Environmental References

Abstract

This study applies calculations and methodologies for the evaluation of concentrations of zinc and nickel coupled to local reference values (background). It also calculates the geoaccumulation index and the intensity of the contamination of the metals according to the deterministic classes established by current standards which set the general guidelines and minimum procedures for the evaluation of material to be dredged in Brazilian jurisdictional waters. These goals are achieved through sampling of sedimentary profiles (core sampling) deposited over the years in the Mãe d’Água reservoir. The results show that the concentrations of zinc and nickel in the samples were above the local background values with growth and enrichment patterns. The results of the geoaccumulation index and current standards indicate that the bottom sediments have pollutant indicators, showing that the existence of sediment enrichment from these metallic elements is probably due to local urbanization activities.