Removal of Triphenylmethane Dye from Aqueous Solution by Carbonaceous Adsorbent

Removal of acid blue 1 from aqueous solution on activated carbon produced from Salvadora oleoides was investigated. The samples were characterized by BET surface area, BJH pore volume and pore diameter, XRD, SEM, EDS and FTIR analysis. The surfaces contain functional groups like ketones and hydroxyl which disappeared at high activation temperature; relatively high amount of carbon w.r.t. oxygen was found with the increase in activation temperature; the increase in surface area and development of porous structures showed a positive effect on the adsorption capacity. Adsorption of the dye on carbon at 10 and 45 degrees C showed that the first order, Bangham and Elovich and parabolic diffusion equations apply to the kinetic data. The adsorption rate increased with the temperature and with thermal activation of the sample. Thermodynamic parameters like Delta E-not equal, Delta H-not equal, Delta S-not equal and Delta G(not equal) were calculated from the kinetic data. The negative values of Delta S-not equal reflect decrease in the disorder of the system at the solid-solution interface during adsorption. Gibbs free energy (Delta G(not equal)), which represents the driving force for the affinity of dye for the carbon, increased with the increase in activation temperature.