Multicycle adsorption and desorption for recovery of U(VI) from aqueous solution using oxime modified zeolite-A

This paper reports synthesis of oxime modified zeolite-A as an efficient adsorbent for uranium (U(VI)). The as prepared adsorbent was thoroughly characterised and the effect of various experimental parameters were also studied. Maximum adsorption occurs in the pH range of 4-6 with adsorption efficiency of 98%. Adsorption experiment results showed that the equilibrium data fitted well to Langmuir model and follow pseudo second order kinetics. More importantly the spent adsorbent was successfully regenerated and multicycles of adsorption and desorption were showing good efficiency in each run. The material is stable and reusable up to 8 cycles with constant adsorption efficiency. The adsorption capacity of 4.92 mg/g is observed for U(VI) in presence of other competing metal ions which include Cr, Cd, Co, Pb and Mn. It can be inferred from the results that oxime modified zeolite-A is a promising adsorbent for recovery of U(VI) due its easy separation, high adsorption and excellent reusability.