Abstrait

Removal of Iron and Manganese from Aqueous Solution Using Hydroxyapatite Prepared from Cow Bone

Olabiyi OG and Adekola FA

Functionalized hydroxyapatite was synthesized from cow bone as model adsorbent for the removal of manganese and iron which often occurs as geogenic contaminants in untreated surface and ground water. The adsorption behaviour was studied by batch method. Prepared adsorbent was characterized using Scanning Electron Microscopy (SEM), Energy Dispersive X-ray (EDX), and X-ray Fluorescence. The effect of initial concentration, pH value of aqueous solution, contact time, adsorbent dose and temperature were the parameters used in determining the optimum conditions of the adsorption process. 60 minutes was established to be the adsorption equilibrium time and the equilibrium adsorption experimental data for the metals were establish to suit the Langmuir adsorption isotherms best and the maximum adsorption capacity was 14.68 mg/g and 2.54 mg/g for Mn and Fe respectively. The adsorption kinetics for the adsorbates was defined best by the pseudo second order kinetic model. The adsorption process is endothermic as revealed by the thermodynamic experiment and the reaction is spontaneous as shown from the values of the free energy change. The hydroxyapatite (adsorbent) was applied to typical raw water with 1.52 mg/l and 3.89 mg/l as the initial concentration of manganese and iron respectively and the removal efficiency for Mn and Fe was 91% and 48% respectively. The results shows that the functionalized hydroxyapatite has great prospective for wastewater and water treatment.