Aplicación de raquis de banano oxidado con reactivo tempo para la adsorción de itrio en soluciones acuosas

Abstract

Rare earth elements such as yttrium have multiple applications in technological devices, but also drawbacks such as its scarcity as it is considered a critical element and water contamination due to its extraction. The current research aims to valorize banana waste using the banana rachis for the manufacture of two adsorbent materials. The first material is the biomass of the banana stem insolubilized with 96% industrial ethanol (MIE) and the second material is from the first, but modified with a reagent called TEMPO (MIE-T). The banana rachis within its chemical composition has holocellulose, cellulose, hemicellulose, lignin and other extractable components. Therefore, both absorbents were characterized to know the percentage of their components, and in all cases the percentage of each component was higher for the MIE bioadsorbent. The adsorption yield and mechanisms were studied by pH dependence studies, equilibrium isotherms, and kinetics.In the adsorption process, the pH parameter plays a very important role, since it significantly affects the activation of the functional groups found in the biomass and also the solubility of the solutes of interest. Phenomena such as the interaction between the solid phase and the aqueous medium where there is release, retention or mobility of a solute at constant pH and temperature can be described by equilibrium adsorption isotherm curves. In order to know the adsorption rates, the activation energy and the limiting mechanisms of a process, it is necessary to carry out a kinetic study of adsorption. Even through all studies we could have the bases to establish design parameters of a reactor for the REE recovery process. Nonlinear mathematical models such as Langmuir and Freundlich were used for the equilibrium study; and for the kinetics study, Pseudo First Order (PPO) and Pseudo Second Order (PSO) models were used.