Sequential fractionation of Pb and Zn in alluvial sediments of the Ribeira de Iguape river

• Grant number: 14/20153-9
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: December 01, 2014
• End date: November 30, 2015
• Field of knowledge: Engineering - Sanitary Engineering - Water Resources
• Principal Investigator: Valéria Guimarães Silvestre Rodrigues
• Grantee: Gabriel de Oliveira Ramos
• Host Institution: Escola de Engenharia de São Carlos (EESC). Universidade de São Paulo (USP). São Carlos , SP, Brazil

Abstract

The Ribeira de Iguape river, received for approximately 40 years, mining waste (tailings from beneficiation and smelting slag) enriched in potentially toxic metals. Studies conducted during the period of mining and ore beneficiation, 1980s and early 1990s activities, found high concentrations of Pb in waters and sediments of Ribeira de Iguape river, its tributaries and Iguape-Cananéia estuarine system. Over the years, the levels of contamination, especially Pb, decreased considerably, both in sediments and in the water. Even with this decrease occurred recently, it was found the incorporation of these toxic elements by filter molluscs (Corbicula fluminea and Anodontites tenebricosus) and standardized concentrations above the PEL / TEL for alluvial sediments collected in the portion between Eldorado and Iporanga value were detected. In this context, the purpose of this research is to evaluate the chemical form (sequential extraction) of Pb and Zn in these alluvial sediments, to determine if these metals are in more or less bioavailable to biota in alluvial sediments that exceeded the PEL values TEL and for Pb and Zn.