Equilibrium studies on the removal of cadmium ion on amberlite IR-120 sorbent

摘要

Adsorption kinetics and isotherms for Cd(II) ions on Amberlite IR-120 in a batch process have been studied under different conditions. The influence of various experimental parameters such as the pH, amount of adsorbent material, initial Cd(II) concentration, contact time and solution temperature, on the removal of cadmium ions has been investigated. The experimental isotherms were analyzed using the Langmuir and Freundlich models. The results suggest that the adsorption of Cd(II) ions on Amberlite IR-120 follows the Langmuir model. The adsorption capacities amounted for 250.63, 258.39 and 259.74 mg/g adsorbent at 28, 50 and 70A degrees C, respectively. Two kinetic models were applied to fit the experimental kinetic data. The best fit was obtained with pseudo-second order model. The thermodynamic parameters were also determined. The activation energy calculated from the rate coefficients at different temperatures was 37.45 kJ/mol. The value of the heat of adsorption suggests the endothermic nature of the cation exchange process.