Behaviors of polyelectrolyte AAm/AMPS/bentonite composite hydrogels in uptake of uranyl ions from aqueous solutions

Abstract

Uranyl ion (UO22+) sorption properties of polyelectrolyte composite hydrogels made by the polymerization of acrylamide (AAm) with 2-acrylamido-2-methyl-1-propanesulfonic acid (AMPS) and clay such as bentonite (Bent) were investigated as a function of composition to find materials with swelling and uranyl ion sorption properties. Highly swollen AAm/AMPS hydrogels and AAm/AMPS/Bent composite hydrogels were prepared by free radical solution polymerization in aqueous solutions of AAm with AMPS as co-monomer and two multifunctional crosslinkers such as ethylene glycol dimethacrylate (EGDMA) and 1,4 butanediol dimethacrylate (BDMA). Swelling experiments were performed in water at 25°C, gravimetrically. The influence of AMPS content in hydrogels was examined. Uranyl ion adsorption from aqueous solutions was studied by batch sorption technique at 25°C. The effect of uranyl ion concentration and mass of AMPS on the uranyl ion adsorption were examined. Finally, adsorption capacity (the amount of sorbed uranyl ion per gram of dry hydrogel) (q) was calculated to be 0.67 × 10−3–2.11 × 10−3 mol uranyl ion per gram for the hydrogels. Removal effiency of uranyl ions (RE%) was changed range 9.05–29.92%. The values of partition ratio (Kd) of uranyl ions was calculated to be 0.10–0.43 for AAm/AMPS hydrogels and AAm/AMPS/Bent composite hydrogels, respectively. POLYM. COMPOS., 2011. © 2011 Society of Plastics Engineers