Novel Polymeric Nanocomposite Sorbent for Rare Earth Elements Extraction: Kinetic Study and Process Feasibility

This study evaluates the Itaconic- Acrlyamide - Tris(2-ethylhexyl)phosphate/ Aluminium oxide IA-AM-TEHP/Al2O3) nanocomposite, synthesized via gamma radiation copolymerization at 25 KGy dose, for extracting rare earth elements (REEs) specifically La(III), Ce(III), Nd(III) and Sm(III) - from waste solutions. Optimal sorption conditions occurred at pH 1.5, a 30-minute contact time, and 1000 mg L⁻¹ REE concentration. A sorption capacity of 145.5 mg g-1 is achieved due to composite functional groups, surface characteristics and hybrid binding active sites confirmed by FTIR, SEM, DTA-TGA and particle size characterization and supported by Redlich-Peterson and Toth models. Mechanistically, the process involves both chemical (coordination, ion exchange) and physical (electrostatic, hydrogen bonding) interactions. The sorption process is exothermic, spontaneous, and follows pseudo-second-order kinetics. Efficient recovery of 92% of REEs was achieved using 0.5 M HCl. The findings highlighting the potential of the nanocomposite for REE recovery and environmental applications.