Sediment grain size distribution and heavy metals determination in a dam on the Parana River at Ilha Solteira, Brazil

This paper reports on a preliminary evaluation of the grain size distribution of cadmium, lead and copper in sediment from Catarina Beach, Ilha Solteira, in the state of São Paulo, Brazil. Surface sediments were fractionated with <63 mu m nylon sieves and subjected to three digestion procedures: the proposed open digestion, the standard USEPA-3050B and closed digestion in a Teflon tube. The metals were determined by atomic absorption spectrometry. The results of the three procedures showed no significant differences. The 309 mg Kg(1) concentration of copper found at the P3 sampling point exceeded the PEL (probable effect level) value of 197 mg Kg(1). which represents an environmental hazard to aquatic organisms. The sediments organic matter content determined by the loss on ignition was 6.8, 1.7 and 0.6% in the P3, P1 and P2 samples, respectively. The distribution of metal concentrations in sieved sediment followed the order P3 < P2 < P1 thereby suggesting an interaction with organic matter.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP