Al2O3 nanoparticles synthesized using various oxidizing agents: Defluoridation performance

This study concerns the removal of fluoride using aluminium oxide nanoparticles synthesized in the presence of oxidizing agents H2SO4, KMnO4 and K2Cr2O7. The obtained nanoparticles were characterized using TGA, FESEM, EDX and XRD. The almost constant weight loss was observed from the TGA data for the temperature range from 400 to 650 °C. XRD analysis with and without oxidizing agents indicated the crystalline behaviour which increased with increasing the temperature. Prepared Al2O3 nanoparticles exhibited a considerable potential for fluoride adsorption from an aqueous medium in the concentration range of 2-8 mg/l. In this case, around 92% fluoride was adsorbed at pH = 4.7. The equilibrium data were well fitted with Freundlich adsorption isotherm, whereas the adsorption kinetic data followed the pseudo second order model.