Removing Fluoride from Drinking Water By Organic Polymers

Fluoride is a substance that can provide beneficial or detrimental effects depending on the total amount ingested. Naturally occurring high fluoride concentrations exist in many drinking water supplies. The fluoride removal methods developed in the past have been found to be either impractical and/or not cost effective. The purpose of this study was to determine whether organic polymers can effectively remove fluoride. The water used in this study contained naturally occurring fluoride concentrations between 4.5 to 5.5 mg/1 and it was collected from the City of Franklin, Virginia, water supply system. Laboratory jar test procedures, which simulated a conventional water treatment plant, were carried out; organic polymers were used as primary coagulants and metal salts and clay were used as coagulant aids. Results indicated that the most effective combination was that of a cationic polymer and alum. At the optimum dosage, the optimum fluoride concentration was achieved without significantly affecting the pH, turbidity, alkalinity, and hardness of the water