AbstractEquilibrium conditions of adsorption of a basic dye on hardwood sawdust were studied using the Langmuir and Freundlich isotherms. Two sets of experiments were carried out at different particle sizes and temperatures. The adsorption of the basic dye on hardwood was found to conform with the two isotherms. The capacity of hardwood for the adsorption of basic dye was found to increase by decreasing the particle size and increasing the temperature. The cost of hardwood adsorbent is only 8.4% that of activated carbon.