Response surface methodology for optimizing adsorption performance of gel-type weak acid resin for Eu(III)

The conditions relating to enhanced adsorption procedure of earth element europium (Eu) onto gel-type weak acid resin (110-H) in aqueous solution were optimized by means of the response surface methodology (RSM), which proved that 110-H owned satisfactory adsorption capacity (346.85 mg/g) in optimum conditions, belonging to one of the high adsorption capacity materials. Then, the adsorption and desorption behaviors were investigated by batch studies. The adsorption performance showed high agreement with the Lagergren-first-order model and Langmuir isotherm with thermodynamic adsorption parameters of ΔH= 36.1 kJ/mol and ΔS=200 J/(mol-K). Desorption study revealed that 110-H could be effectively eluted by a low concentration of HCl solution (0.1 mol/L) to regenerate and reuse. Finally, the 110-H and Eu(III) loaded 110-H were characterized by IR spectroscopy and scanning electron microscope (SEM) to analyze the mechanism of adsorption, which proved to be chemisorbed.