LAUSR

Fipronil, as a broad use insecticide, is regulated under directives and standards in many countries since it is classed as Class II moderately hazardous pesticide and Group C possible human carcinogen. In this study, amine coated iron oxide (NH2-Fe3O4) is used as a new adsorbent with high adsorption capacity in the removal of fipronil from aqueous solution and eggshells. The adsorption performance was studied through batch adsorption under different concentrations of fipronil (10-200 µg/mL), different nanoparticles amount (0.1-1 mg) at different pH (4.5-6.0) and temperature (25-75°C). Results showed that NH2-Fe3O4 nanoparticles (0.1 mg) have excellent adsorption efficiency (97.06%) at 25°C, and pH 5.5. It also showed higher adsorption capacity towards fipronil sulfide, fipronil sulfone and fipronil desulfinyl with removal efficiencies of 92.82%, 86.35% and 76.24% from aqueous solution and 97.62%, 76.97% and 62.65% from eggshells, respectively. Fipronil adsorption process on NH2-Fe3O4 nanoparticles showed best fitting to Langmuir adsorption isotherm indicating monolayer chemical adsorption by physicochemical interactions spontaneously on homogenous surfaces. Having higher adsorption capacity and reusability NH2-Fe3O4 nanoparticles were shown to be effective adsorbents for removal of fipronil from aqueous solution and eggshells.