Synthesis And Evaluation of Ca-Doped Ferrihydrite As A Novel Adsorbent For The Efficient Removal of Fluoride

In this work, a novel calcium (Ca) doped ferrihydrite adsorbent was evaluated for the enhanced adsorption of fluoride (F) from the aqueous phase. The adsorbent properties, adsorption behavior, and mechanism were systematically evaluated. The synthesized adsorbent exhibited tremendous performance in a broad range of temperature and pH. Interestingly, the presence of co-existing anions such as NO 3 - , SO 4 2- , Cl - , and natural organic matter (NOM) have no considerable effect on the adsorption of fluoride from water. The adsorption process was best fitted to the pseudo-second order kinetic model and the Langmuir isotherm. The prepared adsorbent exhibited a maximum adsorption capacity of 53.21 mg/g for the uptake of fluoride from water. The regeneration results confirmed that adsorbent could retain their original adsorption capacity after five regeneration cycles. Results from the current study suggested that Ca-doped ferrihydrite has the application potential for the enhanced adsorption of fluoride from the water phase.