Adsorption of Methylene Red in Solution on Silica Gel: Equilibrium Isotherm and Kinetic Studies

The aim of this study was to remove methylene red from the aqueous solution. In this study, silicagel was used as adsorbent.The experiments were made with 20 mg adsorbents at different pH (2, 3, 4, 7, 10). The experimental data were analyzed using Langmuir, Freundlich, Dubinin-Radushkevich-Kaganer (DKR),Temkin ve Brunauer-Emmett-Teller (BET) isotherm equations and the constants of these equations were determined. The suitability of 20 mg/L dye solution to Langergren pseudo-first order and pseudo-second order rate equations were tested. Thermodynamic parameter such as change of free energy, entalphy and entropy of adsorption were calculated. As a result, the data obtained indicated that adsorption is a physical, exothermic and spontaneous