Studies on the adsorption of indigo dye from aqueous media onto carbonised sugarcane bagasse

Abstract

The ability of Carbonised Sugarcane Bagasse (CSB) to remove indigo dye from aqueous solutions has been studied. Adsorption studies were carried out at different contact time and adsorbent dosage, and the sorption data were modelled using Langmuir, Freundlich and Temkin adsorption isotherms. The results showed that equilibrium was reached within 60 min. Equilibrium data of the adsorption process fitted very well to the Langmuir model (R2=0.9848). Three simplified kinetic models including a pseudo-first-order equation, pseudo-second-order equation and intraparticle diffusion equation were selected to follow the adsorption process. Kinetic parameters, rate constants, equilibrium sorption capacities and related correlation coefficients, for each kinetic model were calculated and discussed. It was shown that the adsorption of indigo dye could be described by the pseudo-second order equation (R2 = 0.9960), indigo dye is transported via intraparticle diffusion into the particles and is finally retained in micropores, suggesting that the adsorption is presumably a physisorption process.