Adsorption of Pb(II) ions from aqueous solutions using copper oxide nanostructures

Abstract

Various morphologies of CuO nanostructures (oval, cluster, leaves, small rod, porus nanosheets) have been synthesized by novel simple method using microwave radiation. The produced CuO nanostructures were characterized by X-ray diffraction analysis technique (XRD), transmission electron microscopy (TEM), surface area analyzer (BET) and energy dispersive spectroscopy (EDS). The ability of CuO nanostructures as adsorbent was investigated for adsorptive removal of Pb(II) ions from aqueous solutions. Various physico–chemical parameters such as pH, initial metal ion concentration, and equilibrium contact time were studied. The optimum solution pH for adsorption of Pb(II) from aqueous solutions was found to be 6.5 and the optimum contact time was found to be 4 h. The adsorption isotherms were obtained using concentrations of the metal ions ranging from 100 to 300 mg/l. The adsorption process follows pseudo-second-order reaction kinetics, as well as Langmuir and Freundlich adsorption isotherms. The maximum capacity of oval, cluster, leaves, small rod and porus nanosheets CuO nanostructures for Pb2+ are 125, 116, 117, 120 and 115 mg/g. This study revealed that CuO nano structures was an effective adsorbent for removal of Pb(II) ions from aqueous solutions.