EM - Escola de Minas
URI permanente desta comunidadehttp://www.hml.repositorio.ufop.br/handle/123456789/6
Notícias
A Escola de Minas de Ouro Preto foi fundada pelo cientista Claude Henri Gorceix e inaugurada em 12 de outubro de 1876.
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3 resultados
Resultados da Pesquisa
Item Iron Quadrangle, Brazil : elemental concentration determined by k0-instrumental neutron activation analysis. Part II: kale samples.(2006) Menezes, Maria Ângela de Barros Correia; Palmieri, Helena Eugênia Leonhardt; Leonel, Liliam Viana; Nalini Júnior, Hermínio Arias; Jacimovic, RadojkoThe objective of this study was to evaluate the influence of mining activity on elemental concentrations in kale grown around a mining area. Two sites studied are in the Iron Quadrangle, Minas Gerais, Brazil, considered one of the richest mineral-bearing regions in the world. One site is near mineral exploration activity and the other is an ecological area. A comparator site outside the Iron Quadrangle was also analyzed. This work focused on the determination of the elemental concentrations in kale applying the k0-instrumental neutron activation analysis. As the Brazilian legislation specifies values for soil only, the results for kale were compared to the literature values and it was found that the vegetable does not present any health risks.Item Arsenic speciation in plant samples from the Iron Quadrangle, Minas Gerais, Brazil.(2005) Daus, Birgit; Wennrich, Rainer; Morgenstern, Peter; Weiß, Holger; Palmieri, Helena Eugênia Leonhardt; Nalini Júnior, Hermínio Arias; Leonel, Liliam Viana; Monteiro, Roberto Pellacani Guedes; Moreira, Rubens MartinsSeveral plants, especially ferns, have been shown to tolerate and accumulate high arsenic concentrations in soils. The leaves and roots of the ferns Pteris vittata (Chinese brake) and Pityrogramma calomelanos as well as a medical plant (Baccharis trimera) were sampled together with their associated soils in a region impacted by ore mining, the Iron Quadrangle in Brazil, where arsenic concentrations in the soils vary sharply (6–900 mgg 1). The bioaccumulation factors were found to be low compared to the literature data, which can be explained by the low water-soluble fraction of arsenic in soil. The arsenic species in the plants were mainly arsenite. In comparison to the rhizoid samples, the concentrations of arsenic were higher in the leaves of the fern samples. The medical plant behaved differently. The bioaccumulation factor was low (0.7), and trimethylarsine oxide was detected as the third arsenic species beside arsenite and arsenate in both the roots and the leaves.Item Quantification and speciation of mercury in soils from the Tripuí Ecological Station, Minas Gerais, Brazil.(2005) Palmieri, Helena Eugênia Leonhardt; Nalini Júnior, Hermínio Arias; Leonel, Liliam Viana; Windmoller, Cláudia Carvalhinho; Santos, Regis Costa; Brito, Walter deContents of total mercury, organic carbon, total sulfur, iron, aluminum and grain size and clay mineralogy were used along with Pearson’s correlation and Hg thermal desorption technique to investigate the presence, distribution and binding behavior of Hg in soils from three depths from the Tripuı´ Ecological Station, located near Ouro Preto, Minas Gerais State, Brazil. The soils studied had predominantly medium and fine sand texture (0.59–0.062 mm), acid character and Hg contents ranging from 0.09 to 1.23 Ag/g. The granulometric distribution revealed that Hg is associated with coarse sand (2–0.59 mm) and silt and clay (b0.062 mm) and presents similar Hg concentrations in both fractions. Mercury distribution in soil profiles showed that Hg was homogeneously distributed throughout the depths at most sites. Hg thermal desorption curves show that mercury occurs not only as Hg2+ predominantly bound to organic components in most of the samples, but also in the form of cinnabar in some. Pearson’s correlation confirmed that mercury is associated with organic matter and sulfur and possibly with sulfur-bearing organic matter in most samples.