Abstract

The present study, agricultural waste tamarind (Tamarindus indica) pod shells were used for the adsorption of dyes like methylene blue and amaranth. The operating variables studied were initial concentration, initial solution pH, adsorbent dosage and contact time. Experimental equilibrium data were fitted to Freundlich and Langmuir isotherms. The kinetics of methylene blue and amaranth onto tamarind pod shells was found to follow a pseudo first order kinetics. The maximum adsorption of amaranth and methylene blue are 65.04 and 60.11 mg/g of the adsorbent respectively. The fourier transformed infrared spectroscopy reveals that –OH, -COOH, C=O and C-O groups are involved in the adsorption process. The optimum pH for the adsorption of amaranth is 2 and methylene blue, a cationic dye shows maximum adsorption in the pH range 6-12. Characterisation of the tamarind pod shells showed that the relative percentage of protein is very less making it an excellent adsorbent for the removal of dyes from wastewater effluents