Özet:

Adsorption equilibrium, kinetics, and thermodynamics of methylene blue dye (MB) from aqueous solutions onto activated carbon (AC) synthesized from pomegranate peel was conducted in controlled batch systems. The effects of initial MB concentration, AC particle size, contact time, and temperature on adsorption were evaluated. Under the optimized conditions (i.e., contact time 120 min, pH ∼ 5, particle size 125 µm, dye concentration 20 mg/L, temperature 333 K, and 0.5 g AC/50 mL MB solution), the removal percentages can achieve ∼ 98.28%. The nonlinear method was conducted for estimating the equilibrium and kinetic parameters, where the equilibrium data were fitted to the Langmuir isotherm model. The Langmuir isotherm suggested a maximum monolayer adsorption capacity of 5.03 mg/g at 60 °C. The pseudo-second-order kinetic model provided the best fit to the experimental data compared with the pseudo-first-order. Kinetic studies showed that the adsorption equilibrium was rapidly established, with low activation energy entailed for adsorption (Ea; 15.60 kJ/mol). Thermodynamic parameters showed that the adsorption was spontaneous (−∆G° and +∆S°), exothermic (+∆H°), and favorable at ambient conditions.

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