Effects of fulvic acid and ferric hydroxide on removal of Fe2+ and Mn2+ by oxidation and aerated/submerged ultrafiltration membrane system

Abstract

The purpose of this study is to evaluate the effects of fulvic acid (FA) and ferric hydroxide on the Fe2+ and Mn2+ removal by oxidation and aerated/submerged membrane systems. Firstly, the oxidation kinetics of Fe2+ and Mn2+ in the presence of FA and ferric hydroxide are discussed and then the contribution of the oxidation step in membrane experiments is determined. All experiments are conducted with synthetic drinking water and the concentration of contaminants is determined by characterization of two different drinking water sources in the city of Istanbul: Omerli Dam Lake and Danamandira Village groundwater. The addition of ferric hydroxide helps to mitigate fouling and enhances the rejection of Mn2+ by up to 90% by developing a secondary filtration layer on the membrane surface which has been considered a challenge in drinking water treatment plants.