Removal of direct dye from aqueous solutions with an adsorbent made from tamarind fruit shell, an agricultural solid waste

Abstract

Removal of a direct dye, Congo Red, has been carried out using tamarind fruit shell (TFS) as an adsorbent. Parameters like agitation time, adsorbent dosage and pH effect have been studied. Adsorption followed the first-order rate expression. The equilibrium data fit well with both Langmuir and Freundlich models of adsorption. Desorption experiments confirmed that major mode of adsorption is ion-exchange for the dye.