Defluoridation of Water by Using Modified Material Developed from Ficus benghalensis Leaf: Characterization, Kinetic and Thermodynamic Study

Abstract

In the present study, microwave-assisted and chemically treated carbonized Ficus benghalensis leaf (MACFBL) material was used as an adsorbent material for the removal of fluoride from water. The results of the characterization of MAFBL carbon material exhibited ideal adsorbent properties. The fluoride adsorption experiments were performed under the batch mode to improve the different affecting parameters such as contact time (0-300 min) and temperature (303-343K) at predetermined pH (5), agitation speed (120 strokes/min), fluoride concentration (2 mg/L) and adsorbent dose (5 g/L). The maximum fluoride removal efficiency of fluoride on MACFBL material was found 86.5 %. The fluoride adsorption data applied for four well known kinetic models such as pseudo first-order, pseudo second-order, intra-particle diffusion, and Elovich kinetic models. The pseudo second-order kinetic study shows the most favourable mechanism for the removal of fluoride. Thermodynamic investigation proposed that the fluoride adsorption process onto MACFBL was exothermic. The instrumental study of MACFBL adsorbent material before and after adsorption during FTIR, SEM, EDX and XRD techniques established the fluoride adsorption on the carbon surface. The developed adsorbent material (MACFBL) is efficient for the removal of fluoride.