Phosphate adsorbed on Fe (III) modified montmorillonite: Surface complexation by ATR-FTIR spectroscopy

LAURA BORGNINO; CARLA EUGENIA GIACOMELLI; MARCELO J. AVENA; CARLOS P. DE PAULI

Elsevier

Año: 2010 vol. 353 p. 238 - 238

p style="TEXT-ALIGN: justify; LINE-HEIGHT: 200%; MARGIN: 0cm 0cm 0pt" class="MsoNormal">This work is aimed at determining phosphate speciation at the Fe(III)-modified montmorillonite/aqueous solution interface by attenuated total reflectance (ATR-FTIR) spectroscopy. IR spectra are analyzed by second derivative and Fourier self-deconvolution procedures to reveal the number and positions of overlapped bands related to phosphate surface complexes. Experiments are conducted at pH 4.5, 7.0 and 9.0 in order to determine the effects of changing pH on the surface speciation. The molecular view offered by the ATR-FTIR measurements is complemented by macroscopic adsorption data, such as adsorption isotherms and electrophoretic mobilities. The ATR-FTIR spectral analyses reveal the existence of two inner-sphere complexes