Removal of Brilliant Blue R from Aqueous Solutions on Activated Carbon Produced from Carbonaceous Substrate

Abstract

Abstract Adsorption of brilliant blue R on activated carbon produced from the wood of Paulownia Tomentosa was investigated. Samples characterization by XRD, SEM, EDS and FTIR showed that the oxygen containing surface functional groups (carboxyls, lactones or phenols and ethers) were present on the surface which were eliminated at 800°C. Activation at 800°C, resulted in the opening of porous structure thereby increasing the adsorption capacity. Relatively high amounts of carbon with respect to oxygen were found in the samples with the rise in activation temperature. The adsorption kinetic at 10 and 45°C showed that the first order, Bangham and parabolic diffusion models are applied to the data. The rate constant increased with the rise in temperature of adsorption/activation. Thermodynamic properties (ΔE≠, ΔH≠, ΔS≠ and ΔGo) for the adsorption process were calculated. Positive values of ΔH≠ showed that the adsorption of brilliant blue R is endothermic. Negative values of ΔS≠ reflected the decrease in the disorder of the system at the solid-solution interface during adsorption. The Gibbs free energy, which is the driving force for adsorption is negative indicating spontaneous adsorption. Freundlich and Langmuir models described the equilibrium adsorption data and Thomas model was used for the column study.