Effect of nanostructure alumina on adsorption of heavy metals

This paper describes the adsorption of heavy metal ions from aqueous solutions by nano structure alumina. Our study tested the removal of three heavy metals: Pb2+, Ni2+ and Zn2+. The optimum contact time, adsorbent mass, and pH were determined, and adsorption isotherms were obtained using concentrations of the metal ions ranging from 25 to 150 mg L− 1. The adsorption process follows pseudo-second-order reaction kinetics, as well as Langmuir and Freundlich adsorption isotherms. The paper discusses the thermodynamic parameters of the adsorption (the Gibbs free energy, entropy, and enthalpy). Our results demonstrate that the adsorption process was spontaneous and exothermic under natural conditions. The maximum capacity of adsorbent for Pb2+, Ni2+ and Zn2+ are 125, 83.33 and 58.82 mg g− 1, respectively. This study revealed that nano structure γ-alumina was an effective adsorbent for removal of these ions from aqueous solutions.