Obtaining adsorbents from acid and acid-thermal activation of bentonite for chlorothalonil pesticide removal

Abstract

Bentonite samples collected from M'Zila of Mostaganem (Algeria) were treated in first protocol with sulfuric acid at concentrations 1, 3 and 6N. The second protocol concerns the acid attack of bentonite combined with thermal treatment at temperatures 100 and 200 °C. The obtained adsorbents were characterized by different analyses techniques such as Chemical composition, XRD, Specific surface area and pHPZC. The modified bentonites were used for removal of Chlorothalonil (Chl) from aqueous solution. The adsorption behavior of the pesticide was studied at different experimental conditions of pH, contact time, concentration of Chl and temperature solution. The adsorption of Chl followed pseudo-second order kinetics and described by Freundlich equation. Thermodynamic study revealed that Chl adsorption was endothermic and physic in nature.