Original Articles: 2010 Vol: 2 Issue: 6
Enhanced adsorption of malachite green dye on chemically modified silica gel
Abstract
Present work was undertaken to chemically modified silica gel with oxalic and citric acid to enhance its adsorption power for malachite green (M G) dye from aqueous solution. Oxalic acid and citric acid modified silica gel was synthesized thermochemically and characterized by Fourier transform infra red (FT-IR) spectroscopy. T he influences of various parameters such as adsorbent dose, pH, initial dye concentration, cont act time and temperature on adsorption were studied. The adsorption data was analyzed using the Langmuir and Freundlich isotherm models. Kinetic studies show that the adsorption follows ps eudo-second order kinetics and intraparticle diffusion model. Negative values of Gibbs free ener gy change ( ∆G°) show that the adsorption was feasible and spontaneous and positive values of enthalpy change ( ∆H°) confirm endothermic adsorption.