Adsorption of lead on gel combustion derived nano ZnO

摘要

Many naturally available materials were used as adsorbents to remove heavy metal ions from water, which are not effective because of low surface area. Novel nano materials are used as adsorbents to remove metal ions to treat potable water. In the present work nano sized large surface area Zinc Oxide (ZnO) was synthesized by gel combustion method and used as an adsorbent to remove lead (II) (Pb~(2÷)) from aqueous solution. The nano ZnO was characterized by X-ray diffraction (XRD), Scanning electron microscopy (SEM), Energy Dispersive X-Ray analysis (EDAX) and surface area analysis. Effect of lead concentration, adsorbent dosage and pH on adsorption was studied. Increase in the initial concentration of Pb, decreases the percentage of adsorption, whereas increase in the adsorbent dosage and pH of the solution, increases the adsorption of Pb~(2+) on ZnO. Synthesized nano ZnO shows almost complete Pb adsorption at lower initial concentration. The equilibrium adsorption capacity of Pb on nano ZnO adsorbent were measured and extrapolated using Langmuir and Freundlich adsorption isotherm models and the experimental data perfectly fits both adsorption isotherms.