SOME PARAMETERS OF THE ADSORPTION OF URANYL IONS IN SUGAR CANE BAGASSE (SACCHARUM OFFICARUM)

Abstract

Introduction:
Uranyl ions are radioactive. Sugar cane bagasse can serve as an adsorbent for these ions.
Objective:
To determine the adsorption parameters in the heterogeneous phase system of uranyl ions in aqueous solution and sugar cane bagasse.
Materials and Methods:
Solutions of uranyl ions whose concentration is determined by UV-VIS absorption. Sugar cane bagasse is used as an adsorbent for which a series of physical and chemical parameters have been determined. Pseudo-first-order, pseudo-second-order and Elovich kinetic models are used. The values of the variation functions of free energy, entropy and enthalpy are determined. The values of the pre-exponential diffusion coefficients are found.
Results and Discussion:
At 298 K and 333 K, the pseudo-first-order model with activation energy of 17.33 kJ/mol is determined. The process is spontaneous, exothermic and low randomness. The chemical potential is 0.83 kJ/mol. The diffusion coefficients are around 10-11m2/s. with a diffusion activation energy of 0.04 J/mol.
Conclusions:
Sugar cane bagasse is an adsorbent with low densities, specific surface area and form factor, but has high tortuosity and porosity. The adsorption at temperatures of 298 and 333 K correspond to a pseudo-first-order model with activation energy of 17.33 kJ/mol. Thermodynamic processes tend to be spontaneous, exothermic and have low randomness. The diffusion coefficients at working temperatures are of the order of 10-11 m2/s.