INFLUENCE OF MODIFICATION OF THE ACTIVATED CARBON ON THE ADSORPTION OF ATRAZINE: EQUILIBRIUM STUDY AND KINETICS

The atrazine removal from aqueous solution on three adsorbents denoted PAC (powder activated carbon), AC - HNO 3 (activated carbon modified with HNO 3 ) and AC - Ag (activated carbon modified with silver) was done. The experimental results obtained showed that, the atrazine removal better fitted the Freundlich model for PAC and the Langmuir model for AC - HNO 3 and both Langmuir and Freundlich models for AC - Ag. Additionally, we saw that, the physicochemical properties of AC - Ag influenced the removal performances of atrazine. The maximum adsorption capacities were, 476,19 mg/g, 434,78mg/g and 357,14mg/g for PAC, AC - HNO 3 and AC - Ag respectively. The Kinetic study performed using the pseudo - first - order, pseudo ? second - order and the intraparticle diffusion models. The regression resu lts showed that the pseudo - second - order model fitted better the experimental data for all the three adsorbents. This study revealed that the adsorption of atrazine was influenced by the surface functionalities and was also controlled by a film diffusion m echanism.