Kinetic and thermodynamic parameters of 99Mo sorption on nano-alumina prepared by precipitation method

Mesoporous γ-Al 2 O 3 nanoparticles were synthesized via isoamyl alcohol-assisted controlled precipitation and characterized using XRD, FTIR, N 2 physisorption, SEM, TEM, and DLS. The nanoparticles exhibited a BET specific surface area of 107.6 m 2 g −1 and a hydrodynamic particle size of 77.3 nm. The effects of pH, contact time, temperature, and initial Mo concentration on 99 Mo sorption were systematically investigated. A maximum sorption efficiency of 96.4 ± 3.0% was achieved at an initial Mo concentration of 5 × 10 −3 M and an equilibrium pH of 3.7 ± 0.1. Langmuir analysis yielded a maximum sorption capacity of 84.5 ± 2.0 mg g-1 at 333 K, while the sorption kinetics were better described by the pseudo-second-order model at 313 and 333 K. Thermodynamic analysis based on a dimensionless conditional Langmuir-derived equilibrium constant suggested favorable and endothermic sorption, with an estimated enthalpy change of +45.3 kJ mol-1. These batch results support further evaluation of γ-Al 2 O 3 nanoparticles for 99 Mo/ 99m Tc generator applications.