Comparative study of phosphates removal from aqueous solutions by nanocrystalline akaganeite and hybrid surfactant-akaganeite

In this study, phosphates removal from aqueous solutions was investigated using synthetic prepared nanocrystalline oxyhydroxide material in unmodified and surfactant modified form. Equilibrium and kinetic studies were carried out to determine the sorption capacity of akaganeite and the rate of phosphate ions uptake. Equilibrium data were analyzed by Langmuir and Freundlich isotherms. The sorption capacity was found to be 59.62 mg P g(-1) for pure nanocrystalline akaganeite and 451.20 mg P g(-1) for hybrid surfactant-akaganeite. Kinetic data followed a pseudo-second-order kinetic model. FT-IR spectra indicate the presence of inner-sphere complexes. Desorption studies showed entirely different behaviour between the two materials. (c) 2006 Elsevier B.V. All rights reserved.