Variação espaço-temporal de metais em aguapé (Eichhornia crassipes (Mart.) Solms)), material particulado aderido às raízes de aguapé e no sedimento em dois rios do sudeste brasileiro

This work evaluated the spatial and temporal variations for metal concentrations (Fe, Mn,Cu, Zn, Ni, Cr e Pb) in water hyacinths [Eichhornia crassipes (Mart.) Solms)] (root and leaves), the particulate material adhering to their roots and the sediment along the Paraiba do Sul River (PSR - high, medium and low) and Imbe River, both in southeastern Brazil. Samples were collected in 2006 at the rainy and dry seasons. Iron and Mn showed the highest concentrations in all samples for both rivers. Roots presented the highest concentrations for all metals. Metal concentrations in the water hyacinths suggest that in the dry season, particularly in the low and medium PSR, metals were more easily bioassimilated, probably due to geochemical and anthropogenic particularities of each region. Overall, PSR presented high contents of metals Cu, Zn, Ni, Cr and Pb compared to the Imbe River, but lower concentrations than those admittedly polluted rivers around the world.