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| Registros recuperados : 48 | |
| 8. |  | MELO, V. F.; NOVAIS, R. F.; BARROS, N. F.; FONTES, M. P. F.; COSTA, L. M. Balanco nutricional, eficiencia de utilizacao e avaliacao da fertilidade do solo em P, K, Ca e Mg em plantios de eucalipto no Rio Grande do Sul. IPEF, Piracicaba, n. 48/49, p. 8-17, 1995.| Biblioteca(s): Embrapa Florestas. |
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| 10. | | RAMOS, M. R.; CURCIO, G. R.; DEDECEK, R. A.; MELO, V. F. de. Disponibilidade de água em solos para reflorestamento no Tabuleiros Costeiros, Município de Itaboraí, RJ. In: CONGRESSO BRASILEIRO DE CIÊNCIA DO SOLO, 33., 2011, Uberlândia. Solos nos biomas brasileiros: sustentabilidade e mudanças climáticas: anais. Uberlândia: Sociedade Brasileira de Ciência do Solo, 2011. 1 CD-ROM.| Biblioteca(s): Embrapa Florestas. |
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| 17. | | MELO, V. F.; WELTER, M. K.; CHAGAS, E. A.; UCHÔA, C. P. Crescimento inicial de mudas de murici em função de doses de pó de rocha. In: SIMPÓSIO INTERNACIONAL DE BOTÂNICA ALICADA, 1.; SIMPÓSIO NACIONAL DE FRUTÍFERAS DO NORTE E NORDESTE, 1, 2012, Lavras. Resumos... Lavras, MG, 2012.| Biblioteca(s): Embrapa Roraima. |
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 | Acesso ao texto completo restrito à biblioteca da Embrapa Florestas. Para informações adicionais entre em contato com cnpf.biblioteca@embrapa.br. |
Registro Completo
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Biblioteca(s): |
Embrapa Florestas. |
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Data corrente: |
12/12/2017 |
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Data da última atualização: |
29/01/2018 |
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Tipo da produção científica: |
Artigo em Periódico Indexado |
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Circulação/Nível: |
A - 1 |
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Autoria: |
BATISTA, A. H.; MELO, V. F.; RATE, A. W.; UHLMANN, A.; GILKES, R. |
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Afiliação: |
Universidade Federal do Paraná; Universidade Federal do Paraná; The University of Western Australia; ALEXANDRE UHLMANN, CNPF; The University of Western Australia. |
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Título: |
More aggressive sequential extraction procedure to access stable forms of Pb and As in clay minerals of soils. |
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Ano de publicação: |
2017 |
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Fonte/Imprenta: |
Applied Clay Science, v. 147, p. 44-53, Oct. 2017. |
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DOI: |
http://dx.doi.org/10.1016/j.clay.2017.05.020 |
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Idioma: |
Inglês |
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Conteúdo: |
Lead (Pb) and arsenic (As) are potentially toxic in their most reactive forms, but can also occur as structural and specifically adsorbed (more stable forms) ions on clay minerals. Due to their lower mobility in soils, structural and specific adsorbed forms are usually neglected in environmental studies, but can be important, for example, in geochemistry researches. The aim of this study was to evaluate the occurrence of stable forms of Pb and As in the clay fraction of soils in a region rich in Pb ore (galena) in south Brazil using more aggressive sequential extractions (boiling 5 mol L−1 NaOH, successive citrate-bicarbonate-dithionite steps, and sodium bisulfate fusion). X-ray diffraction was used to follow possible mineralogical variations after each sequential extraction. We sampled soils from two areas rich in trace elements, with high occurrence of mineral deposits (PbS) in carbonate and phyllite/mica schist rocks. A reference soil formed on mineralized granite/gneiss was also sampled. In different mineral phases of the sequential extraction, preferential association of Pb with minerals extracted by 5 mol L−1 NaOH (kaolinite, low crystalline smectite and precipitated of Pb-S and Pb-P) was observed. In soils formed from parent materials at the phyllite/mica schist metamorphic stage, Pb contents solubilized by NaOH were extremely high (maximum > 28,000 mg kg−1 ). Lead exists in the mineral structure, such as Fe oxides, as result of the isomorphic substitution of Fe for Pb. Manganese oxides were also important host of Pb in the clay fraction. The largest As contents occurred at greater depth in the soil. The more aggressive sequential extraction procedure is more suitable to estimate the structural and specific adsorbed forms of Pb and As in clay minerals. MenosLead (Pb) and arsenic (As) are potentially toxic in their most reactive forms, but can also occur as structural and specifically adsorbed (more stable forms) ions on clay minerals. Due to their lower mobility in soils, structural and specific adsorbed forms are usually neglected in environmental studies, but can be important, for example, in geochemistry researches. The aim of this study was to evaluate the occurrence of stable forms of Pb and As in the clay fraction of soils in a region rich in Pb ore (galena) in south Brazil using more aggressive sequential extractions (boiling 5 mol L−1 NaOH, successive citrate-bicarbonate-dithionite steps, and sodium bisulfate fusion). X-ray diffraction was used to follow possible mineralogical variations after each sequential extraction. We sampled soils from two areas rich in trace elements, with high occurrence of mineral deposits (PbS) in carbonate and phyllite/mica schist rocks. A reference soil formed on mineralized granite/gneiss was also sampled. In different mineral phases of the sequential extraction, preferential association of Pb with minerals extracted by 5 mol L−1 NaOH (kaolinite, low crystalline smectite and precipitated of Pb-S and Pb-P) was observed. In soils formed from parent materials at the phyllite/mica schist metamorphic stage, Pb contents solubilized by NaOH were extremely high (maximum > 28,000 mg kg−1 ). Lead exists in the mineral structure, such as Fe oxides, as result of the isomorphic substi... Mostrar Tudo |
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Palavras-Chave: |
Isomorphic substitution; Pb-P precipitate; Pb-S precipitate. |
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Thesaurus NAL: |
iron oxides; kaolinite. |
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Categoria do assunto: |
-- |
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Marc: |
LEADER 02554naa a2200241 a 4500
001 2082291
005 2018-01-29
008 2017 bl uuuu u00u1 u #d
024 7 $ahttp://dx.doi.org/10.1016/j.clay.2017.05.020$2DOI
100 1 $aBATISTA, A. H.
245 $aMore aggressive sequential extraction procedure to access stable forms of Pb and As in clay minerals of soils.$h[electronic resource]
260 $c2017
520 $aLead (Pb) and arsenic (As) are potentially toxic in their most reactive forms, but can also occur as structural and specifically adsorbed (more stable forms) ions on clay minerals. Due to their lower mobility in soils, structural and specific adsorbed forms are usually neglected in environmental studies, but can be important, for example, in geochemistry researches. The aim of this study was to evaluate the occurrence of stable forms of Pb and As in the clay fraction of soils in a region rich in Pb ore (galena) in south Brazil using more aggressive sequential extractions (boiling 5 mol L−1 NaOH, successive citrate-bicarbonate-dithionite steps, and sodium bisulfate fusion). X-ray diffraction was used to follow possible mineralogical variations after each sequential extraction. We sampled soils from two areas rich in trace elements, with high occurrence of mineral deposits (PbS) in carbonate and phyllite/mica schist rocks. A reference soil formed on mineralized granite/gneiss was also sampled. In different mineral phases of the sequential extraction, preferential association of Pb with minerals extracted by 5 mol L−1 NaOH (kaolinite, low crystalline smectite and precipitated of Pb-S and Pb-P) was observed. In soils formed from parent materials at the phyllite/mica schist metamorphic stage, Pb contents solubilized by NaOH were extremely high (maximum > 28,000 mg kg−1 ). Lead exists in the mineral structure, such as Fe oxides, as result of the isomorphic substitution of Fe for Pb. Manganese oxides were also important host of Pb in the clay fraction. The largest As contents occurred at greater depth in the soil. The more aggressive sequential extraction procedure is more suitable to estimate the structural and specific adsorbed forms of Pb and As in clay minerals.
650 $airon oxides
650 $akaolinite
653 $aIsomorphic substitution
653 $aPb-P precipitate
653 $aPb-S precipitate
700 1 $aMELO, V. F.
700 1 $aRATE, A. W.
700 1 $aUHLMANN, A.
700 1 $aGILKES, R.
773 $tApplied Clay Science$gv. 147, p. 44-53, Oct. 2017.
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