Spatial and temporal evaluation of concentrations of metals in the Educandos basin, Manaus, Amazonas, Brazil

The Educandos basin in Manaus, Amazonas is under threat with sources of metal contamination coming from homes and industry. The objective of this study was to identify the factors that decisively influence the concentration of metals in the Educandos basin. Were selected 14 points of the basin for the collection of water samples. The metal elements were analyzed using inductively coupled plasma optical emission spectrometry (ICP-OES). Pearson correlation, Principal Component (PCA), and Cluster (CA) Analyses were used. The results showed that seasonality has a strong influence on the presence of metals, presenting, for example, average Al values of 187.7 µg.L⁻¹ in the rainy season to 984.3 µg.L⁻¹, and 1,204.2 µg.L⁻¹, behaviour also observed in other metals. PCA showed that, in the rainy season, the behaviour of the concentrations of metals is more homogeneous. In the CA, it was possible to establish the sampling points with possible sources of contamination. The results contribute to understanding of the seasonal processes of the presence and concentrations of metal elements in the waters of the basin.