Permanganate Reduction by Hydrogen Peroxide: Formation of Reactive Manganese Species and Superoxide and Enhanced Micropollutant Abatement

Permanganate (MnO4-, Mn(VII)) is widely applied at the initial stage of water treatment to, e.g., abate taste and odor compounds, Mn(II) and Fe(II). However, its selectivity limits its application for micropollutant abatement. Hydrogen peroxide (H2O2), which is commonly applied in advanced oxidation processes, was found to quickly react with Mn(VII) in the pH-range 6.0-8.5. A lag-phase was followed by a rapid reduction of Mn(VII) to Mn(VI), with a proposed catalysis by the deprotonated form of Mn(VI), for the electron transfer of the H2O2-OMnO3 complex. At molar H2O2:Mn(VII) ratios