Comportamento geoquímico de metais em sedimento das lagoas urbanas de Feira de Santana – Bahia

Abstract

Studying aquatic bodies is fundamental to understanding socio-environmental relationships, as anthropic actions and the natural environment establish a mutual relationship of influence. Amidst the diverse water resources, urban lakes are noteworthy, as they are constantly being modified as a result of population growth. And among the various elements that make up an aquatic body, sediments are important for evaluating the quality of these environments, as they have a high capacity to adsorb contaminants. In this sense, this study aimed to evaluate the concentration and behavior of metals (Fe, Ni, Cd, Zn, Cr, Cu, Mn, Pb) in sediments over time in the main lagoons of Feira de Santana, and thus provide data that explain the superficial contributions. To achieve the purpose of this work, five sediment cores were collected, 3 in Lagoa Salgada and 2 in Lagoa Subaé. The geochemical results obtained in the aquatic bodies showed that they present evidence of contamination by lead in the two lakes and by chromium in the subaé lake. The sediments present granulometric fractions that vary from the siltic sand category to sandy silt. The correlation was significant only between Fe and Mn, as well as Ni and the particle size fractions. While the cluster analysis showed that testimonies 1 - 2 and 3 - 4 had similarities, being 5 different from the others. The IGEO result did not represent contamination in both environments. Therefore, the analyzes allowed us to conclude that the analyzed results do not represent the degree of contamination in the lakes, therefore, a careful look is suggested to avoid future problems in these environments.