Study of the adsorption process of the yellow-orange dye by a bio sorbent derived from the external argan pulp "Argania Spinosa" (isotherms, kinetic and thermodynamic)

Our work aims to increase the worth of a plentiful plant-derived substance, namely the outer pulp of the argan fruit, by utilizing it as a bio sorbent to eliminate yellow-orange food color from a water-based solution, without the need for any physical or chemical preparation. In order to accurately assess the adsorption of JO dye by the bio sorbent, a comprehensive physicochemical characterization was conducted, including FTIR, SEM/EDX, pHpzc with zeta potential, and iodine and methylene blue indices to gather information on the bio sorbent surface. Regarding the process of adsorption, we investigate various types and arrangements of adsorption, as well as the kinetics and thermodynamics of this process. The obtained results demonstrate an adsorption rate of 91% with adsorption being of type S and heterogeneous. The second-order pseudo model is a more accurate representation of our adsorption process. The thermodynamic parameters suggest that the adsorption is both spontaneous and characterized by a chemical, endothermic nature.