Phosphate Adsorption on Metal-Impregnated Activated Carbon

Oak wood based activated carbon was modified with surface impregnation of Fe 3+ and Al 3+ metal ions mixture for enhancements of phosphate adsorption capacity in aqueous solution.The phosphate adsorption capacity of the prepared metal impregnated carbon (MC) was about 8 times higher than that of the original activated carbon (OC).Adsorption equilibrium capacities of the phosphate increased with increasing system temperature.The adsorption equilibrium isotherm of phosphate on the prepared MC could be represented by the Langmuir equation.Thermodynamic parameters also indicated that adsorption system was spontaneous and endothermic reaction.The internal diffusion coefficient was measured to analyze the adsorption behavior and kinetic rate.To determine the internal diffusion coefficient, pore diffusion model (PDM) was employed and the result was in good agreement with experimental data.