Evaluating the Sorption Affinity of Low Specific Activity [sup.99]Mo on Different Metal Oxide Nanoparticles

[sup.99] Mo/[sup.99m] Tc generators are mainly produced from [sup.99] Mo of high specific activity generated from the fission of [sup.235] U. Such a method raises proliferation concerns. Alternative methods suggested the use of low specific activity (LSA) [sup.99] Mo to produce [sup.99m] Tc generators. However, its applicability is limited due to the low adsorptive capacity of conventional adsorbent materials. This study attempts to investigate the effectiveness of some commercial metal oxides nanoparticles as adsorbents for LSA [sup.99] Mo. In a batch equilibration system, we studied the influence of solution pH (from 1–8), contact time, initial Mo concentration (from 50–500 mg∙L[sup.−1] ), and temperature (from 298–333 K). Moreover, equilibrium isotherms and thermodynamic parameters (changes in free energy ΔG[sup.0] , enthalpy change ΔH[sup.0] , and entropy ΔS[sup.0] ) were evaluated. The results showed that the optimum pH of adsorption ranges between 2 and 4, and that the equilibrium was attained within the first two minutes. In addition, the adsorption data fit well with the Freundlich isotherm model. The thermodynamic parameters prove that the adsorption of molybdate ions is spontaneous. Furthermore, some investigated adsorbents showed maximum adsorption capacity ranging from 40 ± 2 to 73 ± 1 mg Mo∙g[sup.−1] . Therefore, this work demonstrates that the materials used exhibit rapid adsorption reactions with LSA [sup.99] Mo and higher capacity than conventional alumina (2–20 mg Mo∙g[sup.−1] ).