Efficient Removal of Fluoride By Lanthanum Modified Carbon Nanoparticles (LMCN)

Excessive fluoride existing in water could result in serious environmental concerns as well as adverse health impact on human being. In the current study, a novel lanthanum-modified carbon nanoparticle (LMCN) was prepared as adsorbent and applied for fluoride removal from aqueous solution. Excellent removal efficiency was observed under a wide range of solution pH, and the maximum adsorption capacity at pH 7 reached up to 48.70mg/g. Further, it was found that 90% removal could be accomplished within the first 1 hour. The adsorption performance can be modeled by Freundlich isotherm at lower equilibrium solute concentration, while Langmuir isotherm better fits the adsorption process when solute concentration is higher. Moreover, the influence of co-existing anions such as PO₄^3-, HCO₃^-, SO₄^2-, SiO₃^2-, AsO₄^3- and humid acid (HA) on the adsorption process was studied. It was found that the fluoride removal efficiency decreased with the increase of ionic strength in the aqueous solution, while no significant impact was identified with the presence of HA. To conclude, LMCN as a low-cost adsorbent can provide fast fluoride removal from aqueous solution with considerably high adsorption efficiency, which leads to potentially wide applications in water treatment.