Equilibrium and Thermodynamic Studys of Adsorption of Azo Dyes on The Local Bentonite Clay

Abstract

This work is included the synthesizs of two azo dyes from the reaction of p-methoxy aniline and 2-amino benzo thiazol .via diazounium ions.A number of clays are tested as adsorbents for the removal of these dyes from their aqueous solution by adsorption . The most efficied one was selected to peforme this study . The prepared dyes are characterized by some of their physical propertier such as(lmax) , (emax) melting point. Stretch bond of (N=N) group by(IR)spectrometry and colours. The optimal condition of the adsorption systems undre study such as effect of does ,initial concentration ,and temperature wear investigated . Two isotherm models,Langmuir and Freundlich were fitted to the experimental data of adsorption .the thermodynamic Function ( ∆H, ∆G°,∆S°) are estimated. The results of the thermodynamic study showed that ,the forces controlling the adsorption process of the systems under considerate are physical in nature . The adsorption process are exothermic , occur spontaneously in the direction of connecting the dye to the clay surface ,and forming less random system.

Keywords

• thermodynamic
• adsorption
• azo dyes
• bentonite clay