Effects of fulvic acid and ferric hydroxide on removal of Fe2þ and Mn2þ 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 Fe2þ and Mn2þ removal by oxidation and aerated/submerged membrane systems. Firstly, the oxidation kinetics of Fe2þ and Mn2þ 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: Ömerli Dam Lake and Danamandıra Village groundwater. The addition of ferric hydroxide helps to mitigate fouling and enhances the rejection of Mn2þ 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.