Metal bioavailability in contaminated estuarine sediments from a highly-impacted tropical bay

Ricardo E. Santelli


The aim of this study is to assess possible spatial variability of trace metal (Cd, Cu, Pb and Zn) bioavailability along the main channel of a highly eutrophic tropical estuary (Iguaçu River estuary, Guanabara Bay, Brazil). Metal potentially-bioavailable concentrations (soluble in 1 mol L-1 HCl) and strongly-bound concentrations (soluble in concentrated HNO3) were sequentially extracted and determined by a Coupled Plasma Optical Emission Spectrometry (ICP OES). These sediments generally have high trace metal contents associated to weakly-bound fractions, while Zn was the most bioavailable metal (approximately 83% of Zn concentrations were weakly-bound to sediments) while Cu showed the greatest heterogeneity of proportion between weakly- and strongly-bound fractions. The employed sampling strategy combined results from sediments taken along and across the estuarine channel, evidencing that care is required when using only a single sampling transect along estuarine channels, particularly for metals sensitive to changes in geochemical partitioning during sediment transport and redistribution, as evidenced by the Cu concentrations in this work.


Metal; bioavailability; geochemistry; sediments; estuary.

Creative Commons License
A Revista Virtual de Química está licenciada sob as condições do Creative Commons Atribuição-Uso Não-Comercial-Compartilhamento pela mesma Licença 2.5 Brasil License. Sob esta licença, a RVQ permite que seu conteúdo seja copiado, distribuído, exibido e executado desde que os devidos créditos à Revista e aos autores sejam dados. Contudo, o usuário não poderá utilizar o conteúdo com finalidades comerciais, a menos que obtenha permissão da Editoria da Revista.
Visitantes Online