Abstract

Metal Fractionation on Fluvial Bed Sediments and the Risk Assessment for Water Supply (Amazonian – Brazil)

Gilmar W. Siqueira, Fabio Aprile, Cláudio N. Alves, Marcelo L. Oliveira1, Afonso S. Mendes1, et al.

Concentrations of metallic elements in sediment from Aurá River basin between 2008 and 2012 were checked, with implementation of two environmental quality criteria for sediments: enrichment factor and degree of chemical and biological contamination. The results showed that the metals Al, Fe, Mn, Cr, Cu, Ni, Pb and Cd had concentrations very close to the limit safe for aquatic biota, and despite of seasonal fluctuations, some metals reached worrying levels with contamination risk for quality of life human resident near the basin. Near the Aurá River mouth there is a pipeline company's state waters, pumping water for Metropolitan Region of Belém. The environmental assessment criteria applied indicated geological enrichment for Fe, Mn, Cr, Ni and Cu, and enrichment of Pb and Cd by the leachate from the landfill closed to drainage basin. According to the criteria of sediments quality used in this study, there is the presence of anthropogenic contamination and impairment of sediments by Pb and Cd.