Removal of Lead Contaminants with γ-Fe2O3 Nanocrystals

Abstract

γ-Fe2O3 (maghemite) nanocrystals were synthesized by co-precipitation method at room temperature have been used to remove Pb+2 from aqueous solutions. The prepared of this sample was characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and vibrating sample magnetometer (VSM). XRD patterns indicated the maghemite structure of average particle size of ∼12 nm, which was further confirmed by the FESEM images of the γ-Fe2O3 nanosrystals. Magnetic saturation of synthesized maghemite was found to be 68.4 emu g–1. Adsorption experiments were tested for pH of the solutions, contact time and initial concentration of metal ions. The kinetic data of adsorption of heavy metal ions on the surface of the synthesized nano-adsorbent was described by a pseudo-second order equation. The adsorption equilibrium study exhibited that the heavy metal ions adsorption of maghemite nanocrystals followed a Langmuir and Freundlich isotherm model. Pb2+ adsorption equilibrium data were best fitted to Langmuir equation and maximum adsorption capacity of 25 mg g–1 was obtained. This work demonstrates that the synthesized γ-Fe2O3 nanocrystals can be considered as prospective nano-adsorbent.