Adsorptive removal of acid blue 15: Equilibrium and kinetic study

Activated carbons prepared from sunflower seed hull have been used as adsorbents for the removal of acid blue 15 (AB-15) from aqueous solution. Batch adsorption techniques were performed to evaluate the influences of various experimental parameters, e.g., temperature, adsorbent dosage, pH, initial dye concentration and contact time on the adsorption process. The optimum conditions for AB-15 removal were found to be pH = 3, adsorbent dosage = 3 g/L and equilibrium time = 4 h at 30 degrees C. The adsorption of AB-15 onto the adsorbent was found to increase with increasing dosage. It was found from experimental results that the Langmuir isotherm fits the data better than the Freundlich and Terrikin isotherms. The maximum adsorption capacity, Q(m) (at 30 degrees C) was calculated for SF1, SF2, and SF3 as 75, 125 and 110 mg g(-1) of adsorbent, respectively. It was found that the adsorption follows pseudo-second order kinetics. The thermodynamic parameters such as Delta G degrees, Delta H degrees, and Delta S degrees were also evaluated. The activated carbons prepared were characterized by FT-IR, SEM and BET analysis.