Adsorption Isotherms of Congo red dye on groundnut shell and sorghum husk

Abstact Using of low cost absorbent is necessary in order to prevent environmental problem. Most of the different methods of water treatments are very expensive, therefore attention most be given to use of cheap absorbent for water treatment. In this research work, sorghum husk and groundnut shell were used to remove Congo red dye in water at the laboratory scale. Batch studies were carried out to determine the adsorption equilibrium of Congo red dye on the two different adsorbent and also to verify the reported data using Langmuir, Freundlich and Temkin isotherm. The studies shows that for the adsorption of Congo red dye on sorghum husk and Congo red dye on groundnut shell, Freundlich isotherm fitted well the experimental data due to high R2 values of 0.983 and 0.9720 respectively. The Temkin binding energy (bT) are positive for the two experiment, indicating that the process is endothermic.