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Registro Completo |
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Biblioteca(s): |
Embrapa Solos. |
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Data corrente: |
03/12/2008 |
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Data da última atualização: |
27/10/2021 |
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Tipo da produção científica: |
Artigo em Periódico Indexado |
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Autoria: |
KEDE, M. L. F. M.; MOREIRA, J. C.; MAVROPOULOS, E.; ROSSI, A. M.; BERTOLINO, L. C.; PEREZ, D. V.; ROCHA, N. C. C. da. |
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Afiliação: |
Maria Luiza F. M. Kede, FIOCRUZ; Josino C. Moreira, FIOCRUZ; Elena Mavropoulos, Centro Brasileiro de Pesquisas Físicas; Alexandre M. Rossi, Centro Brasileiro de Pesquisas Físicas; Luiz Carlos Bertolino, UERJ; DANIEL VIDAL PEREZ, CNPS; Nilce Carbonel Campos da Rocha, UFRJ. |
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Título: |
Estudo do comportamento do chumbo em latossolos brasileiros tratados com fosfatos: contribuições para a remediação de sítios contaminados. |
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Ano de publicação: |
2008 |
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Fonte/Imprenta: |
Química Nova, São Paulo, v. 31, n. 3, p. 579-584, 2008. |
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DOI: |
https://doi.org/10.1590/S0100-40422008000300022 |
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Idioma: |
Português |
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Conteúdo: |
Phosphates have been used for lead immobilization in soils but the influence of soil type is not fully understood. In this work, lead chemical behaviour in two Brazilian latosoils (LA and LV) was studied via treatment with phosphates. The Pb concentration in Toxicity Characteristic Leaching Procedure (TCLP) solutions was decreased in all treatments. After treatment with H3PO4 the Pb concentration in the LA remained within the regulatory limit established by EPA. The ecotoxicological results with Daphnia pulex showed that this treatment reduced the lead bioavailability. Sequential extraction analyses showed that the lead was transferred from the most available to the residual fraction. Relevant decrease of soluble lead was observed in all phosphate treatments. |
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Palavras-Chave: |
Contaminação do solo; Remediação. |
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Thesagro: |
Chumbo; Fosfato. |
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Categoria do assunto: |
P Recursos Naturais, Ciências Ambientais e da Terra |
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URL: |
https://ainfo.cnptia.embrapa.br/digital/bitstream/item/148412/1/a22v31n3.pdf
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Marc: |
LEADER 01593naa a2200253 a 4500
001 1339728
005 2021-10-27
008 2008 bl uuuu u00u1 u #d
024 7 $ahttps://doi.org/10.1590/S0100-40422008000300022$2DOI
100 1 $aKEDE, M. L. F. M.
245 $aEstudo do comportamento do chumbo em latossolos brasileiros tratados com fosfatos$bcontribuições para a remediação de sítios contaminados.$h[electronic resource]
260 $c2008
520 $aPhosphates have been used for lead immobilization in soils but the influence of soil type is not fully understood. In this work, lead chemical behaviour in two Brazilian latosoils (LA and LV) was studied via treatment with phosphates. The Pb concentration in Toxicity Characteristic Leaching Procedure (TCLP) solutions was decreased in all treatments. After treatment with H3PO4 the Pb concentration in the LA remained within the regulatory limit established by EPA. The ecotoxicological results with Daphnia pulex showed that this treatment reduced the lead bioavailability. Sequential extraction analyses showed that the lead was transferred from the most available to the residual fraction. Relevant decrease of soluble lead was observed in all phosphate treatments.
650 $aChumbo
650 $aFosfato
653 $aContaminação do solo
653 $aRemediação
700 1 $aMOREIRA, J. C.
700 1 $aMAVROPOULOS, E.
700 1 $aROSSI, A. M.
700 1 $aBERTOLINO, L. C.
700 1 $aPEREZ, D. V.
700 1 $aROCHA, N. C. C. da
773 $tQuímica Nova, São Paulo$gv. 31, n. 3, p. 579-584, 2008.
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Registro original: |
Embrapa Solos (CNPS) |
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Registro Completo
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Biblioteca(s): |
Embrapa Agroenergia. |
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Data corrente: |
15/03/2019 |
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Data da última atualização: |
18/11/2019 |
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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: |
VICTOR, P. A.; GONCALVES, S. B.; MACHADO, F. |
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Afiliação: |
Priscilla Araújo Victor, UnB; SILVIA BELEM GONCALVES, CNPAE; Fabricio Machado, UnB. |
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Título: |
Styrene/Lignin-Based polymeric composites obtained through a sequential Mass-Suspension polymerization process. |
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Ano de publicação: |
2018 |
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Fonte/Imprenta: |
Journal of Polymers and the Environment, v. 26, p. 1755-1774, 2018. |
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Idioma: |
Português |
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Conteúdo: |
A modified sequential mass-suspension polymerization was employed to ensure adequate dispersion of lignin into the monomeric phase. Due to its complex macromolecular structure and low compatibility with styrene, eucalyptus wood-extracted lignin, via a modified Kraft method, was esterified with methacrylic anhydride to ensure organic phase homogeneity into the reaction medium. Infrared spectroscopy showed a decrease in the hydroxyl band, a characteristic of natural lignin (3200?3400 cm−1) and an increase in the characteristic ester band (1720?1740 cm−1) whereas nuclear magnetic resonance measurements exhibited intense peaks in the range from 1.7 to 2.05 ppm (?CH3) and 5.4 to 6.2 ppm (=CH2), related to methacrylic anhydride. Comparatively, the esterified lignin also displayed an increase of its glass transition temperature for 98 °C, related to natural lignin, whose Tg was determined to be equal to 91 °C. Styrene/lignin-based polymers exhibited higher average molar masses in comparison to the values observed for polystyrene synthesized with similar amounts of benzoyl peroxide, due to the ability of lignin to act as a free-radical scavenger. Composites obtained with styrene and natural or esterified lignin were successfully synthesized, presenting regular morphology and proper lignin dispersion. Based on a very simple polymerization system, it is possible to enhance the final properties of polystyrene through the incorporation of lignin, which represents an important platform for developing attractive polymeric materials from renewable resources. MenosA modified sequential mass-suspension polymerization was employed to ensure adequate dispersion of lignin into the monomeric phase. Due to its complex macromolecular structure and low compatibility with styrene, eucalyptus wood-extracted lignin, via a modified Kraft method, was esterified with methacrylic anhydride to ensure organic phase homogeneity into the reaction medium. Infrared spectroscopy showed a decrease in the hydroxyl band, a characteristic of natural lignin (3200?3400 cm−1) and an increase in the characteristic ester band (1720?1740 cm−1) whereas nuclear magnetic resonance measurements exhibited intense peaks in the range from 1.7 to 2.05 ppm (?CH3) and 5.4 to 6.2 ppm (=CH2), related to methacrylic anhydride. Comparatively, the esterified lignin also displayed an increase of its glass transition temperature for 98 °C, related to natural lignin, whose Tg was determined to be equal to 91 °C. Styrene/lignin-based polymers exhibited higher average molar masses in comparison to the values observed for polystyrene synthesized with similar amounts of benzoyl peroxide, due to the ability of lignin to act as a free-radical scavenger. Composites obtained with styrene and natural or esterified lignin were successfully synthesized, presenting regular morphology and proper lignin dispersion. Based on a very simple polymerization system, it is possible to enhance the final properties of polystyrene through the incorporation of lignin, which represents an importan... Mostrar Tudo |
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Palavras-Chave: |
Compósitos poliméricos; Polimerização sequencial; Polymer composites. |
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Thesaurus NAL: |
Lignin; Styrene. |
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Categoria do assunto: |
-- |
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URL: |
https://ainfo.cnptia.embrapa.br/digital/bitstream/item/194298/1/SILVIA-Victor2018-Article-StyreneLignin-BasedPolymericCo.pdf
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Marc: |
LEADER 02235naa a2200205 a 4500
001 2107112
005 2019-11-18
008 2018 bl uuuu u00u1 u #d
100 1 $aVICTOR, P. A.
245 $aStyrene/Lignin-Based polymeric composites obtained through a sequential Mass-Suspension polymerization process.$h[electronic resource]
260 $c2018
520 $aA modified sequential mass-suspension polymerization was employed to ensure adequate dispersion of lignin into the monomeric phase. Due to its complex macromolecular structure and low compatibility with styrene, eucalyptus wood-extracted lignin, via a modified Kraft method, was esterified with methacrylic anhydride to ensure organic phase homogeneity into the reaction medium. Infrared spectroscopy showed a decrease in the hydroxyl band, a characteristic of natural lignin (3200?3400 cm−1) and an increase in the characteristic ester band (1720?1740 cm−1) whereas nuclear magnetic resonance measurements exhibited intense peaks in the range from 1.7 to 2.05 ppm (?CH3) and 5.4 to 6.2 ppm (=CH2), related to methacrylic anhydride. Comparatively, the esterified lignin also displayed an increase of its glass transition temperature for 98 °C, related to natural lignin, whose Tg was determined to be equal to 91 °C. Styrene/lignin-based polymers exhibited higher average molar masses in comparison to the values observed for polystyrene synthesized with similar amounts of benzoyl peroxide, due to the ability of lignin to act as a free-radical scavenger. Composites obtained with styrene and natural or esterified lignin were successfully synthesized, presenting regular morphology and proper lignin dispersion. Based on a very simple polymerization system, it is possible to enhance the final properties of polystyrene through the incorporation of lignin, which represents an important platform for developing attractive polymeric materials from renewable resources.
650 $aLignin
650 $aStyrene
653 $aCompósitos poliméricos
653 $aPolimerização sequencial
653 $aPolymer composites
700 1 $aGONCALVES, S. B.
700 1 $aMACHADO, F.
773 $tJournal of Polymers and the Environment$gv. 26, p. 1755-1774, 2018.
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