Catalyzed UV oxidation of organic pollutants in biologically treated wastewater effluents

A batch reactor was used to evaluate the efficiency of advanced oxidation p rocess of the organic pollutants in biologically treated wastewater effluen ts with UV/H2O2. A 450-W high-pressure mercury vapor lamp was used as the l ight source. During the degradation process. the concentration of the disso lved organic compounds could be increased by more than twofold due to the d ecomposition of microorganisms. This increase of the dissolved organic comp ounds was eliminated if the water was filtered before the photodegradation experiments. It is observed that the UV alone could play a role for the oxi dation of the organic pollutants; however, the addition of a small amount o f hydrogen peroxide promotes the degradation efficiency of organic compound s in wastewater. The best oxidation efficiency was obtained when the water samples were under acidic conditions (pH 5). and the rate of degradation wa s not enhanced with the increasing H2O2 dosages. The optimum H2O2 dose was between 0.01% and 0.1% for the oxidation processes in this study. The prese nce of the carbonate/bicarbonate ions in water inhibits the degradation of the organic compounds. (C) 2001 Elsevier Science B.V. All rights reserved.