Removal of methylene blue dye from aqueous solutions by elaeagnusan gastifolial as an adsorbent

Abstract

Batch experiments were carried out for the sorption of methylene blue onto elaeagnusan gastifolial particles. The operating variables studied were initial solution pH, contact time, adsorbent dosage and temperature. Equilibrium data were fitted to Freundlich and Langmuir isotherm equation and the equilibrium data were found to well represented by Langmuir isotherm equation. Various thermodynamic parameters such as enthalpy of sorption (AH°), free energy change (AG°) and entropy (AS°) were estimated. The positive value of AH° and negative value of AG° shows the sorption process is endothermic and spontaneous. The positive value of entropy AS° shows the increased randomness at the solid-liquid interface during the sorption of dye ions onto elaeagnusan gastifolial particles.