Sustainable removal of fluorine ions using ZrO2-MgO@C composite

To explore an economic Fluoride-adsorbent with high capacity and superior selectivity as well as easy regeneration, a new synthetic strategy was constructed through a hydrothermal procedure with the aid of glucose to prepare high performance adsorbent ZrO2-MgO@C composite (CZMC). The adsorption capacity and the selectivity toward fluorine ions were evaluated for the synthesized adsorbents. Through characterizations of XRD, BET, SEM, HRTEM, XPS, etc., the crystal structure, the morphology and the chemical composition of the adsorbents were analyzed, illustrating that CZMC has the desirable structure with high dispersion of metal oxides in the porous carbonized microspheres. The results indicate that ZrO2-MgO@C composite show the F-ions adsorption capacity of 184.5 mg/g, with excellent resistance toward disturbance of other anions including NO3-, Cl-, SO42-, CO32- and PO43-. DFT calculations show that the adsorption process of fluorine ions occurs spontaneously and accompanied by orbital hybridization of surface atoms. Such composite adsorbent having high adsorption capacity and superior F-selectivity as well as the feature of easy regeneration would possess promising applications in the treatment of waste water containing fluorine ions.

Automated summary

This study developed a new synthetic strategy to prepare an economic fluoride adsorbent, ZrO2-MgO@C composite (CZMC), with high capacity, superior selectivity, and easy regeneration. Characterization results showed that CZMC possessed a desired structure with high dispersion of metal oxides in the porous carbonized microspheres. The adsorption capacity of CZMC for F- ions was found to be 184.5 mg/g, and it exhibited excellent resistance towards disturbance from other anions. DFT calculations revealed that the adsorption process of fluorine ions occurred spontaneously and involved orbital hybridization of surface atoms. This composite adsorbent with high adsorption capacity, superior F-selectivity, and ease of regeneration holds great potential for the treatment of wastewater containing fluorine ions.