The adsorption of Congo Red by coir pith carbon was carried out by varying the parameters such as agitation time,
dye concentration, adsorbent dose, pH and temperature. Equilibrium adsorption data followed both Langmuir and
Freundlich isotherms. Adsorption followed second-order rate kinetics. The adsorption capacity was found to be 6.7 mg
dye per g of the adsorbent. Acidic pH was favourable for the adsorption of Congo Red. Desorption studies suggest
that chemisorption might be the major mode of adsorption. # 2002 Elsevier Science Ltd. All rights reserved.