A similar observation had been made by Chakraborty et al. [14] when studying the adsorption of Crystal Violet from aqueous solution onto NaOH-modified rice husk and by Mane and Vijay Babu [68] who investigated the adsorption of Brilliant Green dye from aqueous solutions onto NaOH treated saw dust The positive value of ΔH° confirmed the endothermic nature of adsorption of Alizarin Red S dye over mustard husk. Xia et al.