The removal of low levels of organics from aqueous solutions using Fe(II) and hydrogen peroxide formed in situ at gas diffusion electrodes

The removal of several organics (phenol, aniline, acetic acid, formaldehyde , and three azo dyes) from aqueous solutions (pH 2) containing Fe(II) and u sing hydrogen peroxide produced by the reduction of oxygen at a gas-diffusi on electrode is demonstrated. It is shown that chemical oxygen demand of so lutions containing such organics may be reduced by > 90% with a current eff iciency > 50%, leading to acceptable energy consumptions. The approach also clearly has considerable generality. The voltammetry of the gas diffusion electrodes, fabricated by screen printing an XC72-R carbon powder/polytetra fluorene active layer on a carbon fiber paper support is also reported and discussed. (C) 1999 The Electrochemical Society. S0013-4651(98)11-087-X. Al l rights reserved.