Kinetic and mechanism green extraction of ytterbium from ore using organic biosorption nano chitosan oligosaccharide in various membrane thicknesses

Organic biosorption can be used in green hydrometallurgy for Rare Earth Element (REE) as a novel extraction method. Ytterbium is a REE that can be found in the mineral xenotime and monazite. Increasing demand of ytterbium in the world is not balanced by production processes, especially environmentally friendly processes. The purpose of this study is recovery leachate ytterbium solution from ore using membrane nano chitosan oligosaccharide (nano COS) as organic biosorption. Ore that contain mineral ytterbium was resulted from Gorontalo, Indonesia with concentration 0.39 wt% as received and contain 4.29 wt% after alkaline roasting with microwave assisted prior to leaching process. Leaching process was conducted by FactSage software and experimental. FactSage is a software that can perform thermodynamic calculations and predict all chemical reaction phenomena in a relatively short and fast time. FactSage was revealed the optimum leaching process using 3 molar of hydrochloric acid solution with a solid-to-liquid ratio of 1:20, temperature of 20?°C and stirring speed of 150?rpm for 6 hours. Furthermore, adsorption was conducted by variation of thickness of membrane nano COS with parameter pH 1.75 at 45?°C temperature for 5 hours. Next step, desorption was done by 0.1 M EDTA, at temperature 45?°C for 6 hours. All aqueous from adsorption and desorption was measured using UV-Vis and ICP-MS. Meanwhile, the nano-COS membranes after adsorption and desorption were investigated by FTIR. The experimental data were analyzed using the Langmuir and Freundlich isotherm models, as well as pseudo first order and pseudo second order kinetics equations. Under the Langmuir isotherm model, the maximum adsorption capacity of the biosorbent was observed to be 0.0615?mg/g, 0.0118 and 0.0075?mg/g for 1?mm, 2?mm, and 3?mm membranes, respectively, under the specified conditions. The optimum thickness of membrane, which was showed 62.07% adsorption of ytterbium ions from the 2?mm membrane. The analysis of kinetic was determined that the biosorption process followed by pseudo second order kinetics, with linear regression coefficients (R2) of 0.914, 0.958, and 0.978 for 1?mm, 2?mm, and 3?mm membranes, respectively, while first order kinetics showed linear regression coefficients of 0.9440, 0.9715 and 0.9616 for the same membranes.