Adsorption of acid blue 1 on activated carbon produced from the wood of Ailanthus altissima

Abstract

Carbon prepared from the wood of Ailanthus altissima, at 400 and 800ºC was used to adsorb acid blue 1 from aqueous solution at 10ºC and 45ºC. Characterization by XRD, SEM, EDS and FTIR shows that the surfaces contain functional groups like carboxyl which disappear at 800 ºC and thus favor the exposure of more porous structural surfaces which enhance the adsorption capacity. Relatively high amounts of carbon with respect to oxygen were found with the increase in activation temperature. First order, Bangham and parabolic models were found to fit the adsorption kinetic data. The reaction rate increased with the increase in temperature of adsorption/activation. Thermodynamic parameters like ΔE≠ , ΔH≠ , ΔS≠ and ΔG≠ were calculated. The negative values of ΔS≠ reflect the decrease in the disorder of the system at the solid-solution interface, during adsorption. Gibbs free energy ( ΔG≠) represents the driving force for the affinity of dye for the carbon and it decreased with the increase in adsorption/activation temperature.