Studies on the removal of methylene blue dye from water using chitosan

The use of cheap and eco-friendly adsorbents studied as an alternative substitution of activated carbon for removal of dyes from waste water. Chitosan was utilized as adsorbent to remove methylene blue (MB) by adsorption. Batch experiments were conducted to study the effect of pH, initial dye concentration, various adsorbent dosage and these were analyzed using both pseudo first order and pseudo second order equations. The equilibrium adsorption data were analyzed by using the Freundlich and Langmuir isotherms. The equilibrium adsorption capacity (qe) increases with increasing the initial concentration of dye and with decreasing the pH. The maximum colour removal efficiencies of chitosan at dosage of 0.1 g for time duration of 30 min found to be 99% of the dye from a solution of 10 ppm. The pseudo second order kinetic model agrees very well with the dynamic behavior of the adsorption of dye MB on chitosan under different pH, initial dye concentrations and adsorbent dosages. The Freundlich equation is the best fit equilibrium isotherm for the sorption of dye MB onto chitosan based on a linearlized correlation coefficient.