Estudos de metais pesados e isótopos de Pb nos sedimentos da Baía de Sepetiba baseados em geoquímica e na distribuição pelas possíveis áreas fontes

• Autor(a) principal: Rocha, David Silva
• Data de Publicação: 2011
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UERJ
• Texto Completo: http://www.bdtd.uerj.br/handle/1/7066
• topic: Heavy metals; Geochemistry; Pb isotopes; Georeferencing; Sepetiba Bay; Metais pesados; Geoquímica; Isótopos de Pb; Georreferenciamento; Baía de Sepetiba; CNPQ::CIENCIAS EXATAS E DA TERRA::GEOCIENCIAS::GEOLOGIA

The Sepetiba Bay is a coastal lagoon separated from the ocean by beach barrier, situated in the most important economic region in Brazil. The aim of this study was to constrain the Cu, Pb, V, Cr, Cd, Co, Ni and Zn metals concentrations in the sediments of the bay. The maps of concentrations elaborated by lixiviation method showed anomalous sites near Guandu River, Coroa Grande area, Itaguaí Harbour, Martins Island, and anomalous concentrations with NW-SE trend. The results of total digestion revealed contamination by Zn and Cd near Madeira Island associated with Pb and Cr. Anomalous Cu and Zn concentrations observed in Marambaia mangroove is associated with Ni, Pb and Cr. The Pb isotopes yielded results (206Pb/207Pb ratio) betwen 1,23 and 1,27 correlated to industrial garbage and ocurred at two areas: on the east side of mangroove and between Jaguanum and Itacuruçá Islands. were a Higher 206Pb/207Pb isotope value is observed At E/SE from these Islands (1.30), signatures not identified yet in the literature. The marine currents transport the sediments and metals associated at the bay with redistribution from west to east defining a sedimentary plume discharged at rivers mouths. The main responsible by the pollution of Sepetiba Bay are an abandoned Zn ore melt, industrial and domestic waste, atmospheric polutents from metal smelter and autovehicles, and some naval and military activities.