The adsorbent mixed sulfated titania active carbon over silica STAC /SiO2 was synthesized by sol- gel method and was tested for its efficiency in removing Eosin and Saffranin dyes . The parameters studies include contact time, initial dye concentration, magnetic stirring and temperature. Freundlich and Langmuir isotherm models were applied to the equilibrium data. The adsorption capacity (Qm) obtained from the Langmuir isotherm plots with the temperature variation study showed that the Eosin and Saffranin adsorption was endothermic and spontaneous with increased randomness at the solid solution interface. 100% removal of saffranin dye was observed at 40 C. Thermodynamic parameters such as ∆ H° , ∆S° , ∆G° were evaluated . The positive ∆ H° value suggest that the adsorption of Eosin and Saffranin dyes on STAC/SiO2 involves physisorption mechanism. The adsorbent was found to be both effective and economically viable.
Keywords: Eosin and Saffranin dyes, STAC/SiO2 adsorbent, Sol- Gel method
