Keywords: rice husk, kinetic, methylene blue, adsorption, isotherm

Abstract

This study investigate the potential use of untreated rice husk (URH) and base treated rice husk (BRH) for the removal of methylene blue (MB) from aqueous solution. Effect of initial dye concentration, contact time and sorbent dose on sorption were studied. The base treated rice husk had higher adsorption capacities compared to the untreated rice husk. Equilibrium data were fitted to the Freundlich and Langmuir isotherm equations and the equilibrium data were found to be well presented by the Langmuir isotherm equation. The value of qm from the Langmuir model was 25.64 mg g-1 and 111.11 mg g-1 for untreated rice husk and base treated rice husk respectively. Pseudo-first order and pseudo-second order kinetic model were employed to describe the adsorption mechanism. The kinetic data were found to fit pseudo-second order kinetic model with good correlation coefficient. The experimental data obtained in this study indicate that rice husk could be employed as low cost adsorbents in waste water treatment for dye removal.