Extraction and preparation of metal organic frameworks from secondary aluminum ash for removal mechanism study of fluoride in wastewater

AlFuMoF was obtained by purifying the secondary aluminum ash and using hydrothermal method and modification treatment. Next, using the β-Cyclodextrin impregnation treatment AlFuMoF, a modified MOF (β-CD@AlFuMoF) was obtained. Both MOFs were subsequently characterized, and their potential for adsorption of fluoride from wastewater was compared. The characterization was performed by SEM, EDS, FTIR, XRD, particle size change and thermogravimetric. The adsorption characteristics of AlFuMoF and β-CD@AlFuMoF under different conditions of pH, contact time as well as initial concentration were evaluated using kinetic and thermodynamic studies and adsorption isotherms. In terms of dynamics, the pseudo second order model fits the experimental data best. According to the Langmuir model, the maximum fluoride adsorption capacity of AlFuMoF and β-CD@AlFuMoF are 22.56 and 39.95 mg g−1, respectively. Thermodynamic studies show that the adsorption of fluoride on AlFuMoF and β-CD@AlFuMoF are spontaneous and mainly controlled by chemical adsorption. According to the findings, β-CD modification of AlFuMoF can be considered as a promising method for removing fluoride from wastewater.