Azadirachta indica (neem) leaf powder was used as an adsorbent for the removal of textile dye from aqueous solution. The adsorption of dye on A. indica was found to be dependent on contact time, dye concentration and amount of adsorbent. Spectrophotometric technique was used for the measurement of concentration of dye before and after adsorption. The removal data were fitted on Langmuir and Freundlich adsorption isotherm equations. The values of their corresponding constants were
determined from the slope and intercepts of their respective plots. The adsorption isotherm data will employ to calculate the thermodynamic parameters like (G) Gibb’s free energy, (H) change in
enthalpy and (S) entropy. The values of percent removal and KD for Fast green dye on neem leaf powder was also calculated at temperatures ranging from 303-318 K.