Evaluación de los mecanismos de transferencia de masa en el proceso de adsorción de manganeso con bagazo de caña de azúcar en columna de lecho fijo

Abstract

The use of sugarcane bagasse as a bioadsorbent for various pollutants constitutes a promising alternative for its elimination; Currently there are studies on the removal of: Cr+6, Ni+2, Pb+2, Cd+2, Mn+2, acetaminophen, among others. The present research work simulated 3 intraparticular mass transfer models for Mn+2 bioadsorption using sugarcane bagasse. Laboratory-scale tests were first performed on fixed-bed columns to obtain the experimental rupture curves and later the Comsol Multiphysics software was used to simulate the curves by implementing the equations that govern each proposed intraparticle mass transfer model: PSDM (Diffusion of pore and surface) which indicates that inside the pores the adsorbed solute particles are transported through the internal surface of the pore and into the pores without touching the surface. The HSDM (Surface Diffusion) model indicates that only the solute is transported through the inner pore wall and finally the PDM (Pore Diffusion) model indicates that the solute is transported into the pore without touching the inner surface of the pore. The Mn+2 bioadsorption process in a fixed bed column achieved 71.83% removal with a capacity of 4.026 mg / g (mg of Mn+2 ions per gram of adsorbent) with an initial concentration of 4.97 mg / L, feed flow rate of 10 𝑚𝐿/𝑚𝑖𝑛 demonstrating that sugarcane bagasse has a high potential to be used as a bioadsorbent in the process of eliminating manganese from the waters of the Tixán drinking water treatment plant. It was also determined that the intraparticular diffusion model that most influences the process is HSDM (Surface Diffusion); however, the PSDM (Pore and Surface Diffusion) and PDM (Pore Diffusion) models show a high degree of fit. The correlation coefficient R2 ranged between (0.815-0.986) with respect to the experimental curves; This effect is due to the fact that the correlations for the determination of the mass transfer coefficients are empirical and it is very complex to find correlations that adjust to the reality of the adsorption dynamics; however, very similar curves to the experimental curves were simulated. Finally, the similarity in the results of the three intraparticular diffusion models; that is, the little significance between the 3 simulated curves indicates that other empirical equations must be applied to determine the mass transfer coefficients and thus obtain more accurate results