Facile removal of pesticides from aqueous solutions using magnetic nanocomposites II. Adsorption experiments and kinetic study

Abstract

Using previously presented magnetic inorganic/organic magnetic nanocomposites, the adsorption of two known commercial-available pesticides (active ingredients deltamethrin and thiamethoxam, respectively) was achieved. The differences in adsorption observed can be explained by the reduced affinity of the nitro group in the ionized form from thiamethoxam towards the carboxyl groups from chitosan. From the kinetics studies it was determined that in case of thiamethoxam adsorption process is exothermic in nature, while in the case of deltamethrin the process is endothermic. The Sips isotherm was more suitable to describe the adsorption of pesticides on prepared adsorbents. The maximum adsorption capacity determined for the developed material was 247.12 mg/g (for deltamethrin) and 53.29 mg/g (for thiamethoxam).