Kinetics of Palm Kernel Shell in Heavy Metal Ion Sorption

Abstract

The adsorptive capacity of activated palm kernel shell (APKS) on lead (Pb++) and iron (Fe++) was studied. The zinc chloride activated carbons were characterized under pH and iodine number, moisture content, particle size, specific gravity, bulk density, porosity and volume of void. Batch adsorption studies were also carried out under varying experimental conditions  of pH of the solutions, contact time and initial concentration of Pb++ and Fe++ solutions. The results showed that the highest percentage removal of 98.74 occurred at pH = 8 by APKS on Pb++ and the lowest % removal of 20.72 for iron at a PH of 4, though a PH of 7 is recommended. On the effect of contact time, it was found that the equilibrium time for the sorption was at 60mins with the percentage removal of 74.84 on Fe and 65.55 on lead. On the effect of initial concentration, the results showed that the adsorption of Fe increases with the initial concentration, while that of Pb++ decreases with the increase in initial conc. The Langmuir and Freundlich adsorption models were used for the mathematical description of adsorption equilibrium as well. It was deduced from the plot that Langmuir isotherm fitted for modeling the adsorption by APKS on Pb++ and Fe++ while the Freundlich isotherm was inadequate for modeling the APKS