Low-Pressure Discharge Plasma Treatment of Aqueous Solutions with Mn, Cr and Fe
The effect of low-pressure glow discharge on the formation of peroxide and the degree of oxidation of Mn, Cr and Fe was studied in the aqueous solutions of different compounds. The plasma treatment causes the reduction of Mn(VII) through Mn(IV) to Mn(II), Cr(VI) to Cr(III) and oxidation of Fe(II) to Fe(III). Among other reactive species, peroxide formed under the action of plasma treatment takes an active part in redox reactions. The concentration of peroxide usually increases with treatment time, but its presence is detected only after completion of active redox processes.