Study of hexavalent chromium detoxification by living aquatic macrophyte root-based adsorption using high resolution X-ray fluorescence

F.R. ESPINOZA QUIÑOES; N. MARTIN; G. STUTZ; G. TIRAO; S.M. PALACIO; M.A. RIZZUTTO; A.N. MÓDENES; F.G. SILVA JR; N. SZYMANSKI

Recifes

Congreso; XVII Congreso Brasileiro de Engenharia Química – COBEQ 2008; 2008

Asociacion Brasilera de Ingeniería Química

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 solution supplied with non-toxic chromium ion concentrations during 27-days metal uptake experiment in greenhouse. It was not previously observed in nutrient media to occur the reduction from Cr+6 to Cr+3 using a speciation technique. The high-resolution Cr-Kb fluorescence spectra for plant roots were measured using an inelastic X-ray scattering spectrometer at LNLS. X-ray Kb fluorescence spectra of chromium compounds and metallic chromium were also measured and compared to those in roots. For all hexavalent chromium uptake experiments, the spectra resemble not to those of Cr+6 but those of Cr+3. The results suggest that the reduction of Cr+6 to Cr+3 appeared to occur in the roots of all plants.