(242d) Efficient Removal of Fluoride By Lanthanum Modified Seaweeds Sargassum S.P

In this study, a novel lanthanum modified seaweeds (Sargassum S.P.) was prepared and applied in the fluoride removal from the water. The adsorbent showed good adsorption efficiency on the fluoride removal in a wide range of solution pH and the maximum adsorption capacity reached 45mg/g at pH 4. In the kinetic study, it was observed that the adsorption process was very fast and around 75% of its final adsorption was achieved within the first 10 min. The Frenudlich isotherm equation well described the adsorption process. At the optimal pH, adsorption capacities of fluoride were around 125mg/g. The fluoride removal efficiency increased with the increase of the ionic strength in the solution. The effect of common existing anions such as PO₄^3-, HCO₃^-, SO₄^2-, SiO₃^2-and AsO₄^3- and humic acid on the adsorption process was also investigated in detail. The presence of SO₄^2- did not show a significant impact on the fluoride removal while the adsorption efficiency was decreased with the increase of the concentration of other ions and humic acid. From this investigation it was concluded that the La-immobilized seaweed showed the fast fluoride removal from water with very high adsorption efficiency which is beneficial to its application in the water treatment.