Hydrogen peroxide production in capillary underwater discharges

Hydrogen peroxide production by an AC driven capillary underwater discharge was investigated quantitatively. Concentration of formed hydrogen peroxide was measured by a colorimetric method using a specific reaction between H2O2 and a titanium reagent. It comes out that the amount of H2O2 increases linearly during the first hour of the discharge duration and is slightly higher at the high voltage side of the capillary. The initial rate of H2O2 formation by the capillary discharge was therefore determined for initial electrical conductivity of aqueous solution in the range of 100 ÷ 500 µS cm−1. The initial rate of H2O2 formation increases with applied power at fixed initial conductivity of aqueous solution. Experiments performed at fixed applied power indicate that the initial conductivity appears to have only negligible effect on the initial rate of H2O2 formation.