Assessment of heavy metals in sediments of the Sinos river basin, southern Brazil

The present study aimed to evaluate the content of Cu, Cr, Ni, and Zn and their geochemical partitioning in sediments of the Sinos river basin in southern Brazil. This basin has a high population density and a great number of industries, especially metallurgy, electroplating works, steel mills, petrochemicals, and tanneries. The total metal concentrations were determined by X- ray fluorescence, and the concentrations in the sediment phases were determined by applying the BCR- 701 sequential extraction method proposed by the Community Bureau of Reference of the European Community, using ICP/OES. Heavy metal contents were evaluated in the sediment fraction < 63 mu m. Results in the industrialized and densely populated region showed an increase in the total concentrations for Cu, Cr and Zn, and in the mobile fractions for the sequentially extracted metals Cu, Cr, Zn and Ni. Cr stood out particularly in the Portao stream, showing a total concentration of 1286 mg kg(-1), due to the influence of tanneries in this region.