Removal of Heavy Metal by Nickel Oxide Nano Powder

In this study metal oxide nano powder namely NiO nanopowder was prepared. The produced metal oxide was characterized and used as potential adsorbent for the removal of Pb and Zn from aqueous solution. The rate of uptake of the Pb and Zn are rapid in the beginning and the time required for equilibrium adsorption is 120 min. The time of equilibrium as well as time required to achieve a definite fraction of equilibrium adsorption is independent of initial concentration. The results showed that the removal of Pb increased significantly as the pH increased from 2.0 to 6.0 and approach a plateau at pH range of 6.0–9.0., while the removal of Zn increased significantly as the pH increased from 2.0 to 9.0. The adsorption of pb onto NiO follows the Langmiur isotherm, while the adsorption of Zn onto NiO follows the Freundlish isotherm. The pseudo second order kinetic model provided good correlation for the adsorption of Pb onto NiO nanopowder while the pseudo first order kinetic model provided good correlation for the adsorption of Zn onto NiO nanopowder.