Kinetics and Isotherms modeling of methylene blue adsorption by Black Carbon using the shells of apricot kernels

Abstract

Shells of apricot kernels have taken chosen to fabricate the activated black carbon to eliminate the basic dye (methylene blue) from aqueous solutions. The results show the effects of various working conditions counting initial dye concentration (0–25 mg/L), adsorbent dose (0.1–3 g/L), temperature (20–45°C) and pH (2–12) on the uptake of methylene blue were investigated in this experiment-lab study. The adsorption of cationic dye favoured at low temperatures near to the neutral and acids pH for the aqueous solution. Three models have been employed to describe the experimental data for the adsorption isotherm: Langmuir, Freundlich, and Temkin equations. Langmuir isotherm model shows the best results, the thermodynamic parameters such as ΔG, ΔH, and ΔS for the adsorption of methylene blue. The elimination kinetics of methylene blue on black carbon treated at 600oC have been examined by using the pseudo-first-order, pseudo-second-order model equations and intra-particle diffusion, and the pseudo-second-order model was found to define the adsorption process better than the pseudo-first-order equation.