Efficient adsorption of malathion from different media using thermally treated kaolinite

Abstract

Two thermally treated kaolinite samples were prepared at different temperatures. The samples were investigated by means of X-ray powder diffraction (XRD) and thermo-gravimetric analysis (TGA). The adsorption behavior of malathion on untreated and thermally treated kaolinite samples was studied using batch method. The type of the medium of adsorption played an effective role in the nature of the adsorbent–adsorbate interaction and the uptake capacity. In aqueous medium, the thermally treated samples displayed higher uptake capacities (q e = 356.06 and 362.37 μmol/g) relative to that of the untreated one (q e = 311.87 μmol/g). In addition, the thermally treated samples exhibited faster adsorption rates (k 1 = 3.03 × 10–3 and 2.77 × 10–3 min–1) compared with that of the untreated one (k 1 = 1.84 × 10–3 min–1). Desorption of malathion from the loaded samples was also carried out for regeneration purposes. The adsorption/desorption cycle of malathion on the kaolinite samples was repeated several times and the ...