LUCAS STANO JUNQUEIRA
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Resumo IPEN-doc 26819 Sedimentary profiles from a water supply reservoir at São Paulo, Brazil2019 - SILVA, S.A.; JUNQUEIRA, L.S.; FRANKLIN, R.L.; SILVA, W.L.; FAVARO, D.I.T.; MOREIRA, E.G.A research project has been conducted by the Environmental Company of São Paulo State (CETESB) and the Nuclear and Energy Research Institute (IPEN) in important water supply reservoirs at São Paulo State in order to perform a wide evaluation on the content of rare earths and some trace elements in sediment profiles. In the present study, preliminary results for two sampling campaigns at the Graminha reservoir are presented:February/2015 (sites 1 and 3) and August / 2015 (sites 1 and 2). Sediment core samples (around 90 cm long) were collected in the dam and sliced at every 2.5 cm. Instrumental Neutron Activation Analysis (INAA) was applied to the sediment samples in order to determine some trace elements (As, Cr, Th, U and Zn) and rare earth elements (REE) (Ce, Eu, La, Lu, Nd, Sm, Tb and Yb). The analytical methodology validation was performed by means of certified reference material analyses. As, Cr and Zn concentration values were compared to the oriented values from CCME (Canada) (TEL and PEL). Sediment quality was classified as good or very good for these elements according these criteria. Enrichment factor (EF) and Geoaccumulation Index (IGeo index)1were applied to the results by using the concentration values of the last layer of the 90.0 cm profile as background values for sediment contamination index assessment. EF>1.5 was found for REE, U and Th in the middle of the sediment profiles,in all sampling points, indicative of anthropogenic contribution. IGeo values in the range of1