LAUSR

Abstract About 200 million people worldwide drink groundwater containing fluoride concentrations which are above the WHO recommended a maximum permissible level of 1.5 mg/L. In this study, we have used pectin-alginate based biomaterial scaffolds (BMS) within situ functionalized trimetallic oxide Fe-Al-Ce (FAC) for adsorption of fluoride from the water. The Qe of the BMS-FAC, FAC, and BMS are 400, 142.85, and 58.82 mg/g, respectively and the surface area of BMS-FAC is 274.59 m2/g. The adsorption of fluoride follows Langmuir model and kinetics of adsorption follows pseudo-second-order and intraparticle diffusion. The adsorption was feasible, spontaneous, endothermic, and chemisorption in nature i.e. (ΔH > 0, ΔG   0). The better economic viability of BMS-FAC, in comparison to other adsorbents, is shown by the cost-benefit analysis. The adsorbent can be regenerated up to 10 cycles (65%), which makes this method environment-friendly. The leading mechanisms for fluoride adsorption were mainly ion-exchange, electrostatic interactions, and complexation. XPS analysis exposes the key role of the hydroxyl group on the adsorption of fluoride with the adsorbent. This novel synthesis involves cross-linking between two biopolymers by using glutaraldehyde and entrapment of trimetallic oxide in order to increase the active sites as well as the surface area, which makes this a very good adsorbent for adsorption of fluoride.