IFEG   20353
INSTITUTO DE FISICA ENRIQUE GAVIOLA
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Hexavalent chromium detoxification by living aquatic macrophytes root-based biosorption using high resolution x-ray fluorescence
Autor/es:
F.R. ESPINOZA QUIÑONES; G. STUTZ; G. TIRAO; S.M. PALACIO; M.A. RIZZUTTO; A.N. MÓDENES; F.G. SILVA JR; N. SZYMANSKI
Lugar:
Campinas, Brasil
Reunión:
Congreso; XIX Reunión Anual de Usuarios del LNLS; 2009
Institución organizadora:
LNLS
Resumen:
<!-- /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-parent:""; margin:0cm; margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:12.0pt; font-family:"Times New Roman"; mso-fareast-font-family:"Times New Roman";} p.MsoBodyTextIndent, li.MsoBodyTextIndent, div.MsoBodyTextIndent {margin-top:0cm; margin-right:0cm; margin-bottom:0cm; margin-left:27.0pt; margin-bottom:.0001pt; text-align:justify; mso-pagination:widow-orphan; font-size:12.0pt; font-family:"Times New Roman"; mso-fareast-font-family:"Times New Roman"; mso-ansi-language:EN-US; mso-fareast-language:PT-BR;} @page Section1 {size:612.0pt 792.0pt; margin:70.85pt 3.0cm 70.85pt 3.0cm; mso-header-margin:36.0pt; mso-footer-margin:36.0pt; mso-paper-source:0;} div.Section1 {page:Section1;} --> Three species of floating aquatic macrophytes Salvinia auriculata, Pistia stratiotes and Eicchornia crassipes have been chosen to investigate the hexavalent chromium reduced by root-based adsorption at chromium uptake experiment using a high resolution X-ray fluorescence technique. These plants were grown at hydroponics medium supplied with non-toxic chromium ion concentrations during 27-days metal uptake experiment in greenhouse. From a speciation chemical technique, it was not observed in nutrient media to occur the reduction from Cr+6 to Cr+3 due to the changes in the solution pH. The high-resolution Cr-Kb fluorescence spectra for dried roots were measured using an inelastic X-ray scattering spectrometer. X-ray Kb fluorescence spectrum of metallic chromium was used as reference one. From the comparison between Cr2O3 and CrO3 compounds and Cr6+ treated-plant spectra, the energy of Cr-Kb2,5 line resemble not to those for Cr6+ spectra. For all studied plants, the feature of Cr-Kb2,5 line at Cr6+ treated-plant spectra are almost identical in both energy and width to the Cr3+ treated-plant one, indicating that there is the occurrence of a Cr6+ reduction process during the metal biosorption by plants.