Abstract:
Carbon prepared from the wood of Ailanthus altissima, activated at 400 °C and 800 °C was used to adsorb brilliant blue R from aqueous solution at 10 °C and 45 °C. Characterization of the activated carbon by XRD, SEM, EDS and FTIR show that the surfaces contain functional groups like carboxyl`s and ketones which disappeared at 800 °C and favor the exposure of porous structural surfaces which enhance the adsorption capacity. Relatively high amount of carbon with respect to oxygen was found with the increase in activation temperature. First order, Bangham, Elovich, parabolic diffusion and power function equations were found to fit the kinetic adsorption data. The reaction rate increased with the increase in temperatures of adsorption/ activation. Thermodynamic parameters like ?E#, ?H#, ?S# and ?G# were calculated. The. negative values of ?S# reflect the decrease in the disorder of the system at the solid-solution interface, during adsorption. Gibbs free energy (?G#), represent the driving force for the affinity of dye for the carbon and it increased with the increase in adsorption/ activation temperature. The positive value of ?H# shows the endothermic of adsorption and decreases with the increase in adsorption/activation temperature. Batch studies showed that isotherm equations of Langmuir and Dubinin-Radushkevich are applied to the data.
Page(s):
401-414
DOI:
DOI not available
Published:
Journal: Journal of Chemical Society of Pakistan, Volume: 29, Issue: 5, Year: 2007