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Registro Completo |
Biblioteca(s): |
Embrapa Solos. |
Data corrente: |
19/10/2021 |
Data da última atualização: |
19/10/2021 |
Tipo da produção científica: |
Artigo em Periódico Indexado |
Autoria: |
MAVROPOULOS, E.; ROSSI, A. M.; COSTA, A. M.; PEREZ, C. A. C.; MOREIRA, J. C.; SALDANHA, M. F. C. |
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. |
Título: |
Studies on the mechanisms of lead immobilization by hydroxyapatite. |
Ano de publicação: |
2002 |
Fonte/Imprenta: |
Environmental Science and Technology, v. 36, n. 7, p. 1625-1629, 2002. |
DOI: |
https://doi.org/10.1021/es0155938 |
Idioma: |
Inglês |
Notas: |
Na publicação: Marcelo Saldanha. |
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. |
Palavras-Chave: |
Dissolution; Physical and chemical processes. |
Thesaurus Nal: |
Hydroxyapatite; Metals; Sorption. |
Categoria do assunto: |
P Recursos Naturais, Ciências Ambientais e da Terra |
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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Embrapa Solos (CNPS) |
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Biblioteca(s): |
Embrapa Rondônia. |
Data corrente: |
17/09/2015 |
Data da última atualização: |
03/11/2020 |
Tipo da produção científica: |
Artigo em Anais de Congresso |
Autoria: |
FEITOSA, I. L.; PASSOS, A. M. A. dos; CIPRIANI, H. N.; MARCOLAN, A. L.; AKER, A.; TOWNSEND, C. R.; GODINHO, V. de P. C.; MUNIZ, R.; SANTOS, L.; BRUGNERA, F.; MARCILIO, V.; CRUZ, P. G. da; SALMAN, A. K. D.; LOCATELLI, M.; WADT, P. G. S. |
Afiliação: |
Izabela L. Feitosa, INPA; ALEXANDRE MARTINS ABDAO DOS PASSOS, CPAF-RO; HENRIQUE NERY CIPRIANI, CPAF-RO; ALAERTO LUIZ MARCOLAN, CPAF-RO; Andreia Aker; CLAUDIO RAMALHO TOWNSEND, CPAF-RO; VICENTE DE PAULO CAMPOS GODINHO, CPAF-RO; Rafael Muniz, FIMCA; Luvilan Santos, FIMCA; Francis BRUGNERA, FIMCA; Veronice Marcilio, FIMCA; PEDRO GOMES DA CRUZ, CPAFRO; ANA KARINA DIAS SALMAN, CPAF-RO; MARILIA LOCATELLI, CPAF-RO; PAULO GUILHERME SALVADOR WADT, CPAF-RO. |
Título: |
Spatial dependence of ph in a crop-livestock system in the Southwes of Amazon. |
Ano de publicação: |
2015 |
Fonte/Imprenta: |
In: WORLD CONGRESS ON INTEGRATED CROP-LIVESTOCK-FOREST SYSTEMS; INTERNATIONAL SYMPOSIUM ON INTEGRATED CROP-LIVESTOCK SYSTEMS, 3., 2015, Brasília, DF. Towards sustainable intensification: proceedings. Brasília, DF: Embrapa, 2015. |
Idioma: |
Inglês |
Palavras-Chave: |
Spatial dependence. |
Thesaurus NAL: |
soil. |
Categoria do assunto: |
-- |
URL: |
https://ainfo.cnptia.embrapa.br/digital/bitstream/item/129887/1/AP6Y-spatial.pdf
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Marc: |
LEADER 01004nam a2200289 a 4500 001 2024279 005 2020-11-03 008 2015 bl uuuu u00u1 u #d 100 1 $aFEITOSA, I. L. 245 $aSpatial dependence of ph in a crop-livestock system in the Southwes of Amazon.$h[electronic resource] 260 $aIn: WORLD CONGRESS ON INTEGRATED CROP-LIVESTOCK-FOREST SYSTEMS; INTERNATIONAL SYMPOSIUM ON INTEGRATED CROP-LIVESTOCK SYSTEMS, 3., 2015, Brasília, DF. Towards sustainable intensification: proceedings. Brasília, DF: Embrapa$c2015 650 $asoil 653 $aSpatial dependence 700 1 $aPASSOS, A. M. A. dos 700 1 $aCIPRIANI, H. N. 700 1 $aMARCOLAN, A. L. 700 1 $aAKER, A. 700 1 $aTOWNSEND, C. R. 700 1 $aGODINHO, V. de P. C. 700 1 $aMUNIZ, R. 700 1 $aSANTOS, L. 700 1 $aBRUGNERA, F. 700 1 $aMARCILIO, V. 700 1 $aCRUZ, P. G. da 700 1 $aSALMAN, A. K. D. 700 1 $aLOCATELLI, M. 700 1 $aWADT, P. G. S.
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