Removal of basic yellow 28 and tartrazine dyes from water pollution using treated avocado seed: mechanisms, equilibrium, kinetics, and thermodynamics

Abstract

This study focuses on the potential of treated avocado seed to remove azoic organic dyes (basic yellow 28 and tartrazine). The treated avocado seed was characterized, and batch adsorption studies were carried out to evaluate the effects of several removal dye parameters (contact time, ionic strength, initial concentration, adsorbent dose, and temperature). The adsorption kinetics of the dyes examined showed that the adsorption mechanism on the two selected catalysts followed pseudo-second-order kinetics (R2 > 0.999). The adsorption process of each dye was reported to fit using five non-linear regressions. Freundlich and Temkin adsorption isotherms described well the adsorption of basic yellow 28, and Freundlich adsorption isotherms described well the adsorption of tartrazine on the Treated Avocado Seed. The results suggested that the maximum amount adsorbed was 49.30 mg/g for basic yellow 28 and 38.43 mg/g for tartrazine and a high removal rate of 89.93% for BY 28 and 93.22% for tartrazine and that a chemical, spontaneous and endothermic process of adsorption occurred. Boyd’s expression demonstrated a mechanism of film diffusion for adsorption. Based on the findings, we suggest the application of activated avocado seeds for the removal of azoic dyes in aqueous solutions.