Thermodynamics and Kinetics of Adsorption of Crystal Violet by Bentonite

Na-bentonite was used as an adsorbent to adsorb crystal violet from aqueous solution,which served as simulated dye waste water,to study the influence of contact time,initial pH and temperature on its adsorption capacity.An adsorption capacity of 219.75 mg/g was achieved when 40 mL crystal violet with an initial concentration of 250 mg/L and a Ph of 7 was oscillated at 303 K for 35 min,and adsorption capacity increased with temperature.Calculation of the thermodynamic parameters ΔG0,ΔH0 and ΔS0 under different temperatures showed that the adsorption was a spontaneous,endothermic process.The experimental data indicated that the adsorption followed Langmuir isotherm model while the adsorption kinetics fit the pseudo-second-order reaction model.