Design of optimum response surface experiments for adsorption of direct dye on chitosan

The adsorption of direct dye on chitosan was investigated to assess its efficiency in the treatment of waste water streams from dye works. Adsorption isotherms, which will be of use in the design of Box-Behnken design methods, were also experimentally determined. Analysis of variance has been applied to the experimental isotherms. Chitosan, a chelating polymer, is economically attractive because it fan be regenerated; so it is recommended. A response surface method with three levels of temperature (30 degreesC, 45 degreesC, 60 degreesC), pH (6, 7, 8.1, 9.5), and particle size (0.177 mm, 0.914 mm. 1.651 mm) was used in the identification of significant effects and interactions in equilibrium studies. The methodology identifies the principal experimental variables, which have the greatest effect on the adsorption process. Experimental values are in good agreement with predicted values. The correlation coefficient was found to be 0.9886.