Application of Response Surface Methodology For Thorium(Iv) Removal Using Amberlite Ir-120 and Ira-400: Ion Exchange Equilibrium and Kinetics

In this work, thorium(iv) removal from aqueous solutions was investigated in batch systems of cationic and anionic resins of amberlite ir-120 and ira-400. in this way, the effects of ph, initial th(iv) concentration and the amount of adsorbent were investigated. a central composite design (ccd) under response surface methodology (rsm) was employed to determine the optimized condition. the results showed that the maximum removal efficiency of th(iv) onto ir-120 and ira-400 either discretely or in combination, albeit with equal mass fraction, was determined as follows: 98.09% , 65.70% and 72.19% at ph=3.23, 6 and 4.07, initial th(iv) concentration of 78.2, 30 and 55.4 mg.l^-1 and 2.08, 2.5 and 2.2 g.l%-1 of resin, respectively. the kinetic and equilibrium data were accurately described by the pseudo-second order and langmuir models. the results showed that ir-120 is a suitable adsorbent for thorium removal from aqueous solutions.