Riverbank filtration: removal of iron, manganese and hardness

Abstract

This research selects water treatment process that suitable to use by industrial and drinking water to remove high hardness, iron and manganese (Mn) included in bankfiltrate. In hardness removal experiment by membrane, flux of UTC-20 in permeate flux and total hardness removal 0.069 m3/m2/hr that was median value and 93% of removal efficiency was shown, therefore UTC-20 was considered as optimal membrane. After adding manganese dioxide (MnO2) slurry to bankfiltrate containing manganese 4.0 mg/L and adsorption, conclusion of Mn oxidation by potassium permanganate (KMnO4) are as follows; Mn adsorption experiment of MnO2 slurry at 20°C, pH 7.0, 0.28 mol-Mn+2/mol-MnO2 of maximum adsorption amounts by Langmuir isotherm was shown. The reason of decreasing equivalent values after MnO2 slurry addition and adsorption of Mn was the less consuming amounts of KMnO4 in generated MnO2 particle from KMnO4 and Mn reaction and MnO2 slurry added by autocatalytic reaction. Calcium (Ca) and magnesium (Mg) which was contained in bankfiltrate in Mn adsorption by MnO2 slurry showed positive effect in Mn adsorption.