Design of some ferrite-based nanoparticles for uranium removal from Sella leach liquor

Abstract

ABSTRACT Uranium is a non-biodegradable, toxic and radioactive inorganic pollutant that can cause serious human health impacts. This work aims to dip magnesium and lanthanum in ferrite nanoparticles and study their ability to bind uranium ions from uranium leach liquor. MgFe2O4, LaFe2O4 and CeFe2O4 nano-adsorbents were synthesised and characterised. Comparative studies of uranium sorption on the synthesised nano-adsorbents were achieved through a series of experiments at different adsorption conditions. The results show fast uranium sorption on the nanoparticles (with a high efficiency of 86.4 to 91.6), which reflects their higher affinities towards uranium ions. There is a clear improvement in the adsorption capacities of the nanoparticles for uranium binding in adsorption systems at higher temperatures. The maximum adsorption capacity of the MgFe2O4, LaFe2O4 and CeFe2O4 nano-adsorbents was obtained at pH 5, 0.5 g/L (S/L), 400 mg/L (Ci), 333 K and 90 min. The maximum adsorption capacities of uranium on MgFe2O4, LaFe2O4 and CeFe2O4 nanoparticles are 160.4, 118.8 and 129.2 mg/g, respectively. The assessment of the kinetic, isotherm and thermodynamic models was studied to evaluate the reliability and accuracy of these models in predicting the behaviour of uranium adsorption onto the used nanoparticles under various conditions. The outcome of these models confirms the hypothesis of the Elovich, pseudo-second order, Bangham, Langmuir, Dubinin and Radushkevich models to describe the adsorption process. Additionally, it suggests that uranium removal by the nanoparticles takes place through endothermic and spontaneous physio-chemical adsorption reactions. The nanoparticles show high capacity (115.7–142.3 mg/g) and efficiency (78.1–81.7%) for the uranium ions from different uranium-containing samples. These results confirm the high affinity of the synthesised nanoparticles for uranium adsorption in different media.