Stationary and Dynamic Sorption of 141Ce(III) and 152+154Eu(III) Using Alginate–Gypsum Bio-composite Beads

This study introduces a novel Alginate–Gypsum bio-composite, synthesized at a 2:1 weight ratio, as an effective sorbent for Eu(III) and Ce(III) ions in aqueous solutions. Optimal conditions (pH 3, 5-h contact time) yielded 98% sorption efficiency for both ions in single batch systems (50 mg L⁻¹, 20 °C). In binary systems, the composite adsorbed 33.04% of Ce(III) and 47.26% of Eu(III) (mg L⁻¹, 20 °C). Dynamic column system showed 80.297% Ce(III) and 77.5% Eu(III) sorption. The process was endothermic, spontaneous, and best described by a quasi-nth order kinetic model. The sorption process was best described by the quasi-nth order kinetic model, with Eu(III) sorption aligning with the Langmuir and Sips models, and Ce(III) sorption following the Redlich–Peterson and Sips models. Desorption was highly efficient, with up to 99% for Eu(III) and 97% for Ce(III) using 0.1 M EDTA.