Study of methylene blue removal by a biosorbent prepared with apple peels

Abstract

This work investigates the removal of the methylene blue by adsorption using dried apple peels. For this purpose, various experimental parameters were studied: pH [3-10], adsorbent dose [0.25- 3 g/L], solution temperature [10-40°C] and initial concentration of methylene blue [10- 345 mg/L]. Adsorption data were modeled using Langmuir, Freundlich and Temkin adsorption isotherms. The results indicated that the equilibrium data was well represented by Langmuir isotherm with R2 = 0.99. The maximum adsorption capacity is 107.52 mg/g.The Kinetics of methylene blue adsorption using apple peels is described by the pseudo-second order model. In addition, the thermodynamic parameters such as ΔH°, ΔS° and ΔG° were determined, and the dye adsorption process is exothermic.