Efficient adsorptive removal of low concentration fluoride ions from water by cellulose beads with trapped CeO2 nanoparticles

The high electronegativity and solubility of fluoride ions (F - ) in water at low concentrations pose challenges for their treatment and recovery. To effectively adsorb F - , cellulose beads with trapped CeO 2 nanoparticles (CeO 2 @CBs) were fabricated from a NaOH/urea aqueous solution by the optimal extrusion dropping technology. The CeO 2 @CBs exhibited a maximum removal efficiency of 99.15 % for 10.0 mg L −1 F - at 45°C, pH=3.0 and an adsorbent dose of 1.0 g. The CeO 2 @CBs were characterized using SEM-EDS, FT-IR, XRD , and XPS . These findings demonstrate that CeO 2 nanoparticles were uniformly entrapped in cellulose beads and reveal that the removal mechanism involves anionic exchange and electrostatic attractions between protonated hydroxyl on CeO 2 @CBs surface and F - . The results show that the anion competition sequence that affects the F - adsorption efficiency was Cl −