الملخص

The research is included studying the kinetic of the adsorption of two azo dyes synthesized in our laboratories on a local bentonite  thermally activated .The efficiency and capacity of adsorption are calculated at the optimal conditions of adsorption. Such as the effect of dose , contact time ,pH of adsorption medium and temperature . Four kinetic models of  adsorption namely ,pseudo first and second order ,Elovich , and intraparticle diffusion have  been applied on the experimental data of the adsorption system under consideration . The results showed that ,the studied systems are fitted to the pseudo second order model  ,and the adsorption process occurs in more than one mechanism. The activation energy of adsorption of the studied system in addition to the thermodynamic functions of  activation of adsorption are estimated from studying the effect of temperature on the rate constant of adsorption .