TiO2 photocatalytic oxidation of monochloroacetic acid and pyridine: influence of ozone

The influence of ozone on the photocatalytic oxidation of monochloroacetic acid and pyridine with TiO2 (0.5 g/l) at pH 3 (H2SO4) was investigated. Ill umination was performed in a batch reactor (400 mi), with UV-lamp (360-420 nm; 7 x 10(-6) Einstein s(-1)) with continuous introduction of oxygen or oz one containing oxygen. The photocatalytic ozonation of monochloroacetic aci d and pyridine which does not react with ozone alone under given conditions leads to 6 and 24 times higher degradation rates than without TiO2 and 4 a nd 18 times higher rates than without ozone. Moreover the photocatalytic oz onation shows the lowest specific energy consumption (kW h/g DOC-reduction) of the different processes under the experimental conditions. (C) 2000 Els evier Science S.A. All rights reserved.