Iron Oxide-Chitosan-Based Nanocomposite for Efficient Fluoride Removal From Drinking Water

The current study focuses on synthesizing and characterizing iron oxide-based nanoparticles (D-Fe 3 O 4 -NPs) using leave extract of Duranta erecta and iron oxide-chitosan-based nanocomposites (D-Fe 3 O 4 -NC). After successfully fabricating D-Fe 3 O 4 -NC, it is used for the adsorptive removal of fluoride ions (F − ) from water. The characterization study indicated that rough, porous, crystalline, and nanostructure, along with various functional groups of the chitosan, which entrapped the D-Fe 3 O 4 -NPs in D-Fe 3 O 4 -NC and proved its possibility to be effective adsorbents for the quantitative elimination of F − ions. The batch experimental adsorption study indicated that the quantitative removal of F − was achieved at pH (7), initial concentration of metal ions (10 mg L −1 ), the content of D-Fe 3 O 4 -NC (50 mg), contact time (30 min), and temperature (30 °C). The D-Fe 3 O 4 -NC provided 8.82 mM g −1 quantitative F − adsorption capacity. The D-Fe 3 O 4 -NC demonstrated a remarkable following the pseudo-second-order kinetics for successfully removing F − through a monolayer adsorption process following the Langmuir isotherms model. The findings of the thermodynamic study revealed that the D-Fe 3 O 4 -NC followed the exothermic and spontaneous adsorption process for the adsorption of F − . Furthermore, D-Fe 3 O 4 -NC can easily be used several times after washing with diluted HNO 3 for the adsorptive removal of F − . Moreover, the F − is quantitatively adsorbed (> 90%) from the collected drinking water samples.