Brunauer-Emmett-Teller (B.E.T.),Langmuir and Freundlich Isotherm Studies for the Adsorption of Nickel Ions onto Coal Fly Ash

The removal of nickel ions by adsorption process using fly ash was investigated in this study. Nickel removal capacity of fly ash was performed by batch mode adsorption experiment using Atomic Absorption Spectroscopy (AAS) technique. The results obtained were fitted to Brunauer-Emmett-Teller (BET), Langmuir and Freundlich adsorption isotherms using least square fit method. The best fit among the isotherm models is assessed by the linear coefficient of regression (R²) and by non-linear Chi-square test. The theoretical value of q_e calculated from the best fit linear equation of each adsorption isotherm and the experimental values of q_e are plotted against C_e, to compare the experimental and theoretical value of q_e. It was observed by linear and non-linear method that BET adsorption isotherm is best fit for the present investigation.