Uranyl Ion Uptake from Aqueous Solutions by Chemically Cross-linked Polyelectrolyte CAMA Hydrogels

Abstract

Uranyl ion adsorption from aqueous solutions has been investigated by chemically cross-linked polyelectrolyte acrylamide/maleic acid (CAMA) hydrogels. CAMA hydrogels with various compositions were prepared from ternary mixtures of acrylamide (A), maleic acid (MA), and water by free radical polymerization in aqueous solution using multifunctional cross-linkers such as ethylene glycol dimethacrylate (EGDMA) and 1,4-butanediol dimethacrylate (BDMA). Uranyl ion adsorption from aqueous solutions was studied by batch sorption technique at 25°C. The effect of uranyl ion concentration and mass of adsorbent on the uranyl ion adsorption were examined. In the experiments of the sorption, L type sorption in the Giles classification system was found. Some binding parameters such as initial binding constant (K i ), equilibrium constant (K), monolayer coverage (n), site-size (u), and maximum fractional occupancy (Ô) for CAMA hydrogel-uranyl ion binding system were calculated by using Langmuir linearization method. Finally, the amount of sorbed uranyl ion per gram of dry hydrogel (q) was calculated to be 3.29 × 10−4 − 15.87 × 10−4 mol uranyl ion per gram for CAMA hydrogels. Adsorption of uranyl ion was changed range 8.17–48.10%.