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.