Abstract: The feasibility of using nutraceutical industrial Pterocarpus Marsupium spent (PMS) as a cheap biosorbent to adsorb Crystal violet (CV), a cationic dye, from aqueous solution. The influence of initial dye concentration, pH, temperature, adsorbent dosage and particle size on dye adsorption was studied. The experimental equilibrium data obtained were analyzed by isotherm models of Langmuir, Freundlich. The pseudo-first order, pseudo-second order, models were applied for adsorption kinetic studies. The experimental value of the adsorption capacity, qe was 60 mg/g. The kinetic data fitted well to a pseudo-second order model. The thermodynamic parameter values like ?G, ?H and ?S proved that the process of adsorption was exothermic. The FTIR spectra and images of SEM proved the CV being adsorbed onto PMS. Possible interaction that occurred in the CV-PMS system is discussed. PMS is an effective adsorbent to remove CV dye from aqueous solution.

Keywords: Pterocarpus Marsupium Spent; Adsorption, Isotherms, Kinetics