Abstract
Citric acid functionalized magnetic nanoparticles (CA-MNP) were synthesized and studied for sorption of two representative trivalent lanthanide and actinide ions (Eu(3+) and Am(3+)). The material was characterized using various analytical techniques such as FTIR, SEM, TEM and zeta potential measurement etc. which indicated successful synthesis of magnetic nanoparticles and citric acid coating on its surface. The uptake study indicated efficient sorption of Eu(3+) (76.7%) and Am(3+) (60.9%) at optimum concentration of CA-MNP) 2.5 mg mL(- 1). Sorption of metal ion onto the substrate was confirmed by EDXRF results. The sorption process indicated better kinetics for Eu(3+) compared to previously reported studies and both the radionuclides were found to be following pseudo-second order rate kinetics. The rate constants were found to be 4.76 × 10(- 9) mg g(- 1) min(- 1) and 2.45 × 10(- 7) mg g(- 1) min(- 1) for Am(3+) and Eu(3+), respectively. Thermodynamic study indicated ΔG values as - 15.8 kJ mol(- 1) and - 17.9 kJ mol(- 1) for Am(3+) and Eu(3+), respectively indicating the spontaneity of the sorption processes. Stripping with different reagents viz. 0.1 M EDTA, 0.1 M oxalic acid, 0.1 M Na(2)CO(3), and 0.1 M HNO(3) indicated best results with 0.1 M EDTA. >99% of loaded Eu(3+) is stripped in two stripping cycles while stripping of Am(3+) requires more number of cycles to quantitatively strip the loaded radionuclide.