A novel immobilized gel particle material was produced by doping sodium alginate (SA) with poly-γ-glutamate (PGA).The composite exhibited excellent capacity for adsorbing rare earth elements (REEs).The factors that potentially affected the adsorption efficiency of the SA-PGA composite,including the initial concentration of REEs,the adsorbent dosage,and the pH of the solution,were investigated.Fifteen types of REEs in single and mixed aqueous solutions were used to explore the selective adsorption of REEs on the SA and SA-PGA gel particles.