EFFICIENCY OF GRANULAR FERRIC HYDROXIDE (GFH) FOR REMOVAL OF FLUORIDE FROM WATER

Granular ferric hydroxide (GFH), a combination of poorly crystallized FeOOH, was investigated for removal of fluoride (F) from water. Adsorption was studied in batch experiments at room temperature together with the effect of contact time, pH, initial F concentration, and SO42- and Cl- as interfering anions. Lower pH with higher initial F concentration and longer contact time increased the F removal efficiency. In the absence of interfering anions, maximum removal of F approaching 88 percent was achieved at pH 6 after 30 min from water containing 7 mg F/L. Considering economic and feasibility aspects, adsorption of F with GFH is recommended as a successful method of F removal from water and wastewater treatment plants.