Adsorption of furfural from aqueous solution onto activated carbon: Kinetic, equilibrium and thermodynamic study

The present study aims to evaluate the influence of various experimental parameters viz. initial pH (pH(0)), adsorbent dose, contact time, initial concentration and temperature on the adsorptive removal of furfural from aqueous solution by commercial grade activated carbon (ACC). Optimum conditions for furfural removal were found to be pH(0) approximate to 5.9, adsorbent dose approximate to 10g/1 of solution and equilibrium time approximate to 6.0h. The adsorption followed pseudo-second-order kinetics. The effective diffusion coefficient of furfural was of the order of 10(-13)m(2)/s. Furfural adsorption onto ACC was found to be best represented by the Redlich-Peterson isotherm. A decrease in the temperature of the operation favorably influenced the adsorption of furfural onto ACC. The positive values of the change in entropy (Delta S-0); and the negatived value of heat of adsorption (Delta H-0) and change in Gibbs free energy (Delta G(0)) indicated feasible, exothermic, and spontaneous nature of furfural adsorption onto ACC.