Color impurity in industrial effluents constitutes a significant risk to human health and the environment, so much effort has been expended to degrade them using various methods, including the use of agricultural waste materials as adsorbent. The purpose of this study was to provide understanding of the mechanisms for the removal of eosin yellow from aqueous solutions onto pineapple peels as adsorbent. The adsorption equilibrium was studied on effects of initial adsorbate concentration, initial solution pH, and contact time using batch equilibrium techniques. The fitness of equilibrium data to common kinetic models such as pseudo first order, pseudo second order, intraparticle diffusion and film diffusion were tested. From the results obtained for the adsorption experiments, the best adsorption potential was recorded at eosin yellow concentration of 250 mg/L (q_e =12.49 mg/g), agitation time of 90 minutes (q_e=13.35 mg/g) and initial solution pH of 3 (q_e= 22.01 mg/g). Results of kinetic study revealed the order of fittings: Intraparticle diffusion (R² = 0.981) > Pseudo first order (R² = 0.978) > Liquid film diffusion (R² = 0.972) > Pseudo second order (R² = 0.96). The goodness of fit was observed with the various kinetic models tested, indicating the applicability of these models in the adsorption of eosin yellow on pineapple peels. Thus, the results of the study could provide useful information to evaluate pineapple peels for the practical removal of eosin yellow from aqueous solution.

Keywords:Adsorption, Eosin yellow, Kinetic models, Pineapple peels