Thermodynamics and kinetics of the adsorption of UTP onto the duolitea-30 resin

Ion-exchange thermodynamics and kinetics of uridine 5′-triphosphate (UTP) by weakly basic anion-exchange resin DuoliteA-30 have been investigated. The equilibrium isotherms were obtained in a range of temperature and heat of adsorption (ΔH), Gibbs free energy (ΔG), entropy of adsorption (ΔS) were calculated according to the relationship of the thermodynamic function. The equilibrium data obtained in this study have been found to fit the Langmuir adsorption isotherm. Thermodynamic parameters depict the endothermic nature of adsorption and the process is spontaneous and favorable. On the other hand, the kinetics of ion exchange process was studied under different conditions namely temperature, initial UTP concentration, particle radium, stirring speed and initial solution pH. The extraction process is characterised by a sharp moving boundary between the reacted shell and the shrinking unreacted core within the resin. Analyses of the rate data showed that the process was controlled by the rate of diffusion of the ions penetrating the reacted layer at UTP concentrations in the experimental range. The activation energy (E_a), reaction order (n) and adsorption rate constants (k) were determined from the graphical representation of the proposed model.