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Luiz-Silva Wanderson Maceira Maria Elvira Pieiro Rotunno Filho Otto Corra Chou Sin Chan 《Environmental Modeling and Assessment》2022,27(1):13-28
Environmental Modeling & Assessment - The São Francisco River Basin plays a critical role in the hydroelectrical operational planning of Brazil. Understanding the hydroclimatic dynamic... 相似文献
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Machado W Luiz-Silva W Sanders CJ Patchineelam SR 《Journal of environmental radioactivity》2008,99(8):1329-1334
Concentrations of fertilizer industry-derived P (up to 3.4%), Ca (up to 6.1%), (226)Ra (up to 744 Bq kg(-1)) and (210)Pb (up to 1317 Bq kg(-1)) at least one order of magnitude above natural levels were recorded in a sediment core from Morr?o River estuary (SE Brazil). Unsupported (210)Pb (= total (210)Pb-(226)Ra) activities unexplained by atmospheric fallout and deviations from the radionuclides secular equilibrium also indicated strong anomalies. Anomalous constituents were positively correlated with each other and negatively correlated with clay mineral-bearing elements. These negative correlations were explained by a depletion of natural sediment constituents due to a dilution caused by elevated inputs of steel industry-derived elements (mainly by Fe levels up to 24%). Absolute data and normalizations by a proxy for clays (Al) and anthropogenic Fe evidenced variabilities in the quality of coastal and land-derived sediment inputs, mainly due to changes in the relative contributions from industrial sources. 相似文献
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In anoxic sediments, as those found in estuaries, the mobility of metals can be controlled by the formation of stable sulfide
complexes. The potential bioavailability of a metal can then be predicted on the basis of the acid volatile sulfide (AVS)
and simultaneously extracted metals (SEM) criterion. Distributions of AVS and SEM (Hg, Cu, Pb, Cd, Zn, and Ni) along the sediment
profiles were determined seasonally for three rivers that constitute the Santos-Cubat?o estuarine system (SE Brazil), which
is located in one of the most industrialized areas of Latin America. AVS and SEM concentrations varied significantly, from
0.04 to 31.9 μmol g−1 and 0.086–6.659 μmol g−1, respectively. The highest AVS levels in sediments were detected in the winter, whereas high SEM values predominated in the
summer. Considering SEM–AVS molar differences as a parameter to evaluate potential bioavailability, sediments nearest to the
industrial area represent higher risk to biota, especially during the summer. It is due to relatively low AVS values and not
necessarily high concentrations of metals. 相似文献
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Alice Bosco-Santos Wanilson Luiz-Silv Emmanoel Vieira da Silva-Filho Monique Dias Corrêa de Souz Elton Luiz Dantas Margareth Sugano Navarro 《环境科学学报(英文版)》2017,29(4):69-76
Fractionation of rare earth elements (REE) and other trace metal concentrations (Th, U, Cd, Cr, Cu, Ni, Pb, and Zn) between mangrove sediments and claw muscles and shells of male crabs (Ucides cordatus) from a subtropical estuary highly impacted by fertilizer industry activities was investigated. This is the first record of REE distribution in these organisms, and the results showed higher accumulations of these metals, U and Th in shells, probably related to the replacement of Ca during molting. Contents of Cd, Cr and Ni were similar in both tissues, but Cu, Zn and Pb were mostly accumulated in the claw muscle with concentrations above those considered safe for human consumption according to the Brazilian legislation. REE fractionation was different in the analyzed tissues being softer in the shells. The results provided evidences that the water absorbed during molting controls the chemistry of REE in shells. In contrast, the chemistry of REE in the claw muscle, in which was observed preferential absorption of light REE, is controlled by diet. REE fractionation obtained for the claw muscles was closely correlated to the observed in the contaminated substrate and in materials related to the production of phosphate fertilizers (contamination source), which supports their transference to this Ucides cordatus tissue without fractionation by the ingestion of sediments. Our results showed the potential use of crab tissues for monitoring REE and trace element sources in mangrove areas, with claw muscle exhibiting the contaminant source fingerprint. 相似文献
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