SRTXRF analysis in sediments from the Paraiba do Sul river (Brazil)

The Paraiba do Sul is a medium-sized river located in a region between the two most important urban and industrial centers of Brazil (Rio de Janeiro and Sao Paulo), with 1145 km in length and a drainage basin of 55400 km2. Formed by the junction of the Paraibuna and Paraitinga rivers, it arises in Serra da Bocaina (Sao Paulo state) and flows to the Atlantic Ocean until its mouth in Atafona (Rio de Janeiro State). In the last years, has been reported an increase in the water pollution, caused by the untreated domestic sewerage of the inhabitants, effluents discharged by various industries, mining activities and sand extraction of the riverbed. Consequently, a decline in the diversity and abundance of the fish species has been observed. This work used the Total Reflection X-Ray Fluorescence with Synchrotron Radiation (SRTXRF) technique to determine the heavy metals levels in the bioavailable and residual fractions from the surface sediment, in sampling points along the Paraiba do Sul River Basin. The samples were collected from November 2002 to April 2003. The analysis was performed at XRF beamline D09B of the Brazilian Synchrotron Light Laboratory (LNLS), using a white beam for the excitation and a Si(Li) semiconductor detector with resolution of 165 eV. All samples were excited for 100 s. The elements found in the sediment samples were: Ti, Cr, Mn, Fe, Cu, Zn, Rb, Sr, Ba and Pb. (author)