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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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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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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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