Kinetics, Isotherm and Thermodynamic Studies of The Adsorption Behavior of Basic Yellow 51 Onto Rice Husk and Burned Rice Husk

Abstract

In this work, rice husk and burned rice husk were used as low cost adsorbents to remove a cationic dye, Basic Yellow 51(BY51) , from aqueous solution by adsorption. Characterization of rice husk and burned rice husk was carried out with Scanning Electron Microscope and Fourier Transform Infrared Spectroscopy. The effects of operational parameters on the efficiency of dye removal including initial dye concentration, contact time, pH, and temperature were investigated. All series experiments were carried out in batch mode. Equilibrium data were analyzed using Langmuir and Freundlich isotherm models and monolayer adsorption capacity was calculated. Kinetic data were studied using pseudo first order and pseudo second order kinetic models and dye removal was found to follow the pseudo second order kinetic model closely. Thermodynamic parameters such as enthalpy change (\uf044H°), entropy change (\uf044S°) and free energy change (\uf044G°) were also investigated. Free energy change showed that adsorption of Basic Yellow 51 was spontaneous at all studied temperatures for rice husk and burned rice husk. It is proposed that rice husk and burned rice husk may be suitable as adsorbents for removal of cationic dyes from aqueous solution.