Metals biogeochemistry in river sediments from Turvo/Grande Watershed

Abstract

In this study, we conducted to characterize the metal species Al, As, Ba, Cd, Cr, Ni, Fe, Mn, Zn, Sb, Pb, Cu and K samples of pore water, the sample sediment-water interface and sediment collected at Black rivers, and Cloudy in the Great Basin Dim / Large. This work aims to evaluate the quality of the sediments of this basin as well as providing a preliminary analysis of the flow of metal species in the sediment-water interface with emphasis on the role of sediment as a source or sink of metals. For this, there will be two sediment samples (surface and depth profile) at intervals of six months between each other, being a representative of the period of drought and flood in another seven sampling sites along the Black river, and Cloudy Great Basin in the Dim / Large. For the main bodies of water (dam of Black River, damming the Rio Grande River and impoundment Turvo) will be held on the same day, three collections in each of these sampling sites, in order to assess the degree of heterogeneity of the sediments of water bodies , two located near the banks and another in the central region. For the sediment samples collected in the last three sampling locations will be collected the water from the sediment-water interface and the extraction of pore water in accordance with the recommendations of the literature. In all samples of sediment-water interface and sediment pore water will be performed to quantify the total stock of metal (Al, As, Ba, Cd, Cr, Ni, Fe, Mn, Zn, Sb, Pb, Cu and K (emission mode)) using Atomic Absorption Spectrophotometer with electrothermal atomization (GFAAS) or flame (FAAS). It will also be performed to characterize the sediments for pH, content of C, H and N, particle size and moisture content, as well as quantification of pH, conductivity, total dissolved solids, dissolved organic carbon and turbidity in the samples of interstitial water. These parameters will be quantified also in samples of the sediment-water interface beyond the parameters temperature and dissolved oxygen. The reliability of analytical results will be verified by determining the figures of merit of the analytical methods used for quantification, as well as the use of certified reference material. To calculate the diffuse fluxes of metal species in the sediment-water interface will be using the first Fick's Law. The results of this work will enable data to generate virtually nonexistent in the region in order to assess the quality of the sediment basin in question, and to quantify the flows of metal species in the sediment-water interface. Finally, you can assess the degree of pollution and the role of sediments in this basin.