Adsorption of Nickel Ions from Aqueous Solutions by Nano Alumina: Kinetic, Mass Transfer, and Equilibrium Studies

The presence of nickel in aquatic systems due to discharge of industrial effluents is of concern because of its toxic and nonbiodegradable nature. Its removal from water and wastewater is mandatory. Though activated carbon has been effective in removing metallic species including nickel from water and effluents, its high cost limits its large scale application to developing nations. The present paper addresses the removal of nickel from aqueous solutions by alumina nano particles. The adsorbent, nano alumina powder, was synthesized in the laboratory and was characterized by X-ray diffractometry (XRD), Fourier transformation infrared spectroscopy (FTIR), and transmission electron microscopy (TEM). The BET surface area and porosity of nanosized alumina powder were found to be 78.79 m(2) g(-1) and 0.51, respectively. The initial concentration of nickel, agitation speed, and contact time were found to affect the removal of nickel from aqueous solutions. Kinetic studies were performed and pseudofirst order, second order, intraparticle diffusion, and mass transfer studies were carried out. The equilibrium data were analyzed by various isotherms viz. Langmuir, Freundlich, Dubinin-Radushkevich, and Temkin and Pyzhev isotherms. Results of the present study revealed that nano particles of alumina powder can be used for a large scale treatment of water containing Ni(II) in particular and that of pollutant species in general.