Kinetics and Thermodynamics of Uranium Adsorption from Commercial Di-hydrate Phosphoric Acid Using D2EHPA-Impregnated Charcoal

Di (2-ethylhexyl) phosphoric acid (D2EHPA) in acetone was supported on charcoal. The use of D2EHPA impregnated in charcoal for the adsorption of uranium (VI) ions from commercial di-hydrate phosphoric acid was carried out using batch technique. The different factors affecting uranium adsorption such as time, volume of the aqueous solution to weight of adsorbent ratio (V/m), and temperature has been studied. The uranium adsorption percent is increasing by decreasing values of V/m ratio and decreasing temperature. The kinetic models applied to the adsorption rate data were evaluated for Lagergren first order and the pseudo second order models. From the results, the adsorption process was found to obey a Lagergren pseudo first order rate model. The uranium adsorption process shown the exothermic character and the thermodynamics parameters (∆H, ∆G and ∆S) were - 21.6 ± 0.3 kJ/mol, - 10.09 ± 0.03 kJ/mol and -39.8 ± 0. 9 J/mol K respectively.