Selective Separation of Europium from Lanthanum, Cerium, and Iron Using Porous and Functionalized Polymer

Abstract

Europium (Eu) ion is one of the most important and valuable lanthanide elements for nuclear and industrial applications. In this respect, the present study was oriented to prepare a new selective porous polymer using an efficient method for controlled synthesis of block copolymers and polymeric porous particles. Reversible-addition−fragmentation chain transfer (RAFT) emulsion polymerization was performed using poly(styrene-crotonic acid-methacrylic acid) PS(CA-MAA) and trithiocarbonate as a surfactant. The new polymer PS(CA-MAA) was prepared by grafting the polymerization of polystyrene with reactive monomers using γ-rays. The new polymer was investigated for the separation of Eu(III) from light REEs (LREEs) such as La(III), Ce(III), and some impurities such as Fe(III). Different characterizations of the prepared polymer were carried out. Batch experiments were conducted to determine the effects of pH, contact time, and concentration on the sorption and separation of Eu(III) from other light lanthanides and Fe(III). The obtained results revealed that the prepared polymer is more highly selective for Eu(III) than the other LREEs. Lanthanide sorption processes were well fitted to the monolayer sorption isotherm model, with the maximum sorption capacities of 2.51, 7.75, and 45.45 mg g −1 for La(III), Ce(III), and Eu(III), respectively. Pseudo-second-order kinetic models obey the experimental data, suggesting a chemical sorption reaction via a strong complex formation on the surface of PS(CA-MAA). According to the separation factor, separation of Eu from other investigated lanthanides was successively performed and took the order SF(Eu/La)> SF(Eu/Ce), which encouraged further utilization of the prepared polymer for the column chromatographic separation process.