Adsorption behavior of some metal ions on hydrated amorphous titanium dioxide surface

Titanium dioxide was prepared from titanium tetrachloride and diluted ammonia solution at low temperature. The product obtained was characterized by XRD, EDXRF, TGA, DSC, and FT-IR techniques. It was found that the product was in the form of hydrated amorphous titanium dioxide, TiO2·1.6H2O (ha- TiO2). Ha-TiO2 exhibits high BET surface area at 449 m2/g. Adsorptions of metal ions onto the ha-TiO2 surface were investigated in the batch equilibrium experiments, using Mn(II), Fe(III), Cu(II), and Pb(II) solutions. The concentrations of metal ions were determined by atomic absorption spectrometer. The adsorption isotherms of all metal ions were studied at pH 7. The adsorption of Mn(II), Cu(II), and Pb(II) ions on ha-TiO2 conformed to the Langmuir isotherm while that of Fe(III) fit equally well to both Langmuir and Freundlich isotherms.