Scavenging fluoride from the aqueous system with porous organometallic three-dimensional architecture: An emerging adsorbent.

To provide safe water to the suffering community, a porous, and three-dimensional architecture (ZrLMA) is presented for the removal of fluoride from contaminated water. The structural moiety of ZrLMA contains zirconium dimethacrylate (ZrDMA) and lauryl methacrylate (LMA). Various experimental factors, i.e., the effect of adsorbent's dose, feed concentration of fluoride, pH, pHpzc, and interfering ions, are investigated to evaluate its performance. The binding energy between ZrLMA and F- ions is investigated by density functional theory and found to be - 271.3 kJ mol-1, which indicates a high level of interaction between ZrLMA and F- ions at atomic and molecular levels. Freundlich and Langmuir adsorption isotherm models are best fitted with the obtained experimental data with the maximum adsorption capacity for fluoride as 19.8 mg g-1 (pH 7.0 ± 0.2, initial F- concentration: 10 mg l-1 and dose: 0.5 g l-1). The kinetics and thermodynamic parameters (ΔG, ΔH, and ΔS) are also investigated. The uniqueness of the adsorbent is due to its covalently co-ordinated metallic-polymeric moiety, which provides stable architecture during the sorption process irrespective of the nature of the surrounding medium. Due to its absolute structural integrity, the adsorbent does not leach out any trace elements (Zr, F-) in the treated water during the adsorption process while maintaining original characterstics of the water from field water samples as well. An attempt has been made to recover fluoride at the end of the process. Hence, the approach is environment friendly for the remediation and recovery of pollutants due to its excellent reusability with effluent treatment.