Removal of tannic acid from aqueous solutions by activated carbons

Three activated carbons from olive stones have been used in this study. Their surface area ranges from 1127 to 1350 m² g⁻¹ and their pore volume accessible to water from 0.491 to 0.682 cm³ g⁻¹. The behaviour of these activated carbons to remove tannic acid from aqueous solutions, under both static and dynamic conditions, has been studied. Under static conditions their adsorption capacity varies from 54.2 to 96.2 mg g⁻¹; whereas under dynamic conditions only a low fraction of this capacity is utilized (less than 2%). All these results are discussed on the basis of the textural characteristics of the activated carbons.