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 | Acesso ao texto completo restrito à biblioteca da Embrapa Solos. Para informações adicionais entre em contato com cnps.biblioteca@embrapa.br. |
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Registro Completo |
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Biblioteca(s): |
Embrapa Solos. |
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Data corrente: |
19/10/2021 |
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Data da última atualização: |
19/10/2021 |
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Tipo da produção científica: |
Artigo em Periódico Indexado |
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Autoria: |
MAVROPOULOS, E.; ROSSI, A. M.; COSTA, A. M.; PEREZ, C. A. C.; MOREIRA, J. C.; SALDANHA, M. F. C. |
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Afiliação: |
ELENA MAVROPOULOS, CBPF; ALEXANDRE MALTA ROSSI, CBPF; ANDRÉA M. COSTA, CBPF; CARLOS ANDRÉ C. PEREZ, NUCAT; JOSINO C. MOREIRA, FIOCRUZ; MARCELO FRANCISCO COSTA SALDANHA, CNPS. |
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Título: |
Studies on the mechanisms of lead immobilization by hydroxyapatite. |
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Ano de publicação: |
2002 |
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Fonte/Imprenta: |
Environmental Science and Technology, v. 36, n. 7, p. 1625-1629, 2002. |
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DOI: |
https://doi.org/10.1021/es0155938 |
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Idioma: |
Inglês |
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Notas: |
Na publicação: Marcelo Saldanha. |
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Conteúdo: |
The sorption of lead by synthetic hydroxyapatite (HA) from solutions containing Pb2+ initial concentrations up to 1770 mg L-1 was studied. X-ray diffractometry (XRD) associated with Rietveld methodology for refining the spectra pattern was used in order to characterize the mechanisms of lead uptake. It is shown that the dissolution of hydroxyapatite is followed by the formation of a solid solution, Pb(10-x)Cax(PO4)6(OH)2, with Pb ions mostly occupying Ca(II) sites. The Ca/Pb molar ratio of this solid solution decreases continuously until it reaches the structure of a pure hydroxypyromorphite. The cell parameters and the crystallite mean size behavior of both mineral phases reinforce the hypothesis that hydroxypyromorphite, PbHA, formation is the end of a process in which Pb(10-x)Cax(PO4)6(OH)2 crystallites are continuously dissolved and recrystallized producing crystals with lower calcium content. Combination of Inductively Coupled Plasma spectrometry (ICP), chemical analysis, and XRD results permitted the conclusion that lead ions are not completely immobilized by precipitating Pb(10-x)Cax(PO4)6(OH)2. Additional surface mechanisms also contribute to Pb2+ uptake. During Pb2+ sorption process, pH variations of the solution phase showed a more complex pattern than previously reported. Contribution of surface mechanisms, in addition to the hydroxyapatite dissolution, could explain this behavior. |
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Palavras-Chave: |
Dissolution; Physical and chemical processes. |
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Thesaurus Nal: |
Hydroxyapatite; Metals; Sorption. |
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Categoria do assunto: |
P Recursos Naturais, Ciências Ambientais e da Terra |
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Marc: |
LEADER 02218naa a2200265 a 4500
001 2135443
005 2021-10-19
008 2002 bl uuuu u00u1 u #d
024 7 $ahttps://doi.org/10.1021/es0155938$2DOI
100 1 $aMAVROPOULOS, E.
245 $aStudies on the mechanisms of lead immobilization by hydroxyapatite.$h[electronic resource]
260 $c2002
500 $aNa publicação: Marcelo Saldanha.
520 $aThe sorption of lead by synthetic hydroxyapatite (HA) from solutions containing Pb2+ initial concentrations up to 1770 mg L-1 was studied. X-ray diffractometry (XRD) associated with Rietveld methodology for refining the spectra pattern was used in order to characterize the mechanisms of lead uptake. It is shown that the dissolution of hydroxyapatite is followed by the formation of a solid solution, Pb(10-x)Cax(PO4)6(OH)2, with Pb ions mostly occupying Ca(II) sites. The Ca/Pb molar ratio of this solid solution decreases continuously until it reaches the structure of a pure hydroxypyromorphite. The cell parameters and the crystallite mean size behavior of both mineral phases reinforce the hypothesis that hydroxypyromorphite, PbHA, formation is the end of a process in which Pb(10-x)Cax(PO4)6(OH)2 crystallites are continuously dissolved and recrystallized producing crystals with lower calcium content. Combination of Inductively Coupled Plasma spectrometry (ICP), chemical analysis, and XRD results permitted the conclusion that lead ions are not completely immobilized by precipitating Pb(10-x)Cax(PO4)6(OH)2. Additional surface mechanisms also contribute to Pb2+ uptake. During Pb2+ sorption process, pH variations of the solution phase showed a more complex pattern than previously reported. Contribution of surface mechanisms, in addition to the hydroxyapatite dissolution, could explain this behavior.
650 $aHydroxyapatite
650 $aMetals
650 $aSorption
653 $aDissolution
653 $aPhysical and chemical processes
700 1 $aROSSI, A. M.
700 1 $aCOSTA, A. M.
700 1 $aPEREZ, C. A. C.
700 1 $aMOREIRA, J. C.
700 1 $aSALDANHA, M. F. C.
773 $tEnvironmental Science and Technology$gv. 36, n. 7, p. 1625-1629, 2002.
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Registro original: |
Embrapa Solos (CNPS) |
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Biblioteca |
ID |
Origem |
Tipo/Formato |
Classificação |
Cutter |
Registro |
Volume |
Status |
URL |
Voltar
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Registro Completo
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Biblioteca(s): |
Embrapa Semiárido. |
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Data corrente: |
15/12/1999 |
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Data da última atualização: |
15/02/2022 |
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Tipo da produção científica: |
Resumo em Anais de Congresso |
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Autoria: |
ALENCAR, J. A. de; HAJI, F. N. P.; BARBOSA, F. R.; ALENCAR, P. C. G. de. |
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Afiliação: |
JOSE ADALBERTO DE ALENCAR, CPATSA; FRANCISCA NEMAURA PEDROSA HAJI, CPATSA; FLAVIA RABELO BARBOSA, CPATSA. |
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Título: |
Eficácia dos reguladores de crescimento Buprofesin e Pyriproxyfen sobre as fases imaturas da mosca branca na cultura do melão. |
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Ano de publicação: |
1999 |
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Fonte/Imprenta: |
In: ENCONTRO LATINO AMERICANO E DO CARIBE SOBRE MOSCAS BRANCAS E GEMINIVIRUS, 8., 1999, Recife. Anais e mini-resumos... Recife: IPA, 1999. |
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Páginas: |
p. 102. |
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Idioma: |
Português |
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Conteúdo: |
Foi cultivado o melão híbrido melody. |
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Palavras-Chave: |
Cucurbitacea; White flies. |
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Thesagro: |
Controle Químico; Cucumis Melo; Cucurbitaceae; Melão; Mosca Branca; Regulador de Crescimento. |
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Thesaurus NAL: |
Bemisia argentifolii; chemical control; melons; plant growth substances. |
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Categoria do assunto: |
O Insetos e Entomologia |
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URL: |
https://ainfo.cnptia.embrapa.br/digital/bitstream/CPATSA/8496/1/OPB604.pdf
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Marc: |
LEADER 01010nam a2200301 a 4500
001 1133747
005 2022-02-15
008 1999 bl uuuu u00u1 u #d
100 1 $aALENCAR, J. A. de
245 $aEficácia dos reguladores de crescimento Buprofesin e Pyriproxyfen sobre as fases imaturas da mosca branca na cultura do melão.
260 $aIn: ENCONTRO LATINO AMERICANO E DO CARIBE SOBRE MOSCAS BRANCAS E GEMINIVIRUS, 8., 1999, Recife. Anais e mini-resumos... Recife: IPA$c1999
300 $ap. 102.
520 $aFoi cultivado o melão híbrido melody.
650 $aBemisia argentifolii
650 $achemical control
650 $amelons
650 $aplant growth substances
650 $aControle Químico
650 $aCucumis Melo
650 $aCucurbitaceae
650 $aMelão
650 $aMosca Branca
650 $aRegulador de Crescimento
653 $aCucurbitacea
653 $aWhite flies
700 1 $aHAJI, F. N. P.
700 1 $aBARBOSA, F. R.
700 1 $aALENCAR, P. C. G. de
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