SOLAR PHOTODEGRADATION OF XENOBIOTIC CONTAMINANTS IN POLLUTED WELL WATER

The photodegradation of xenobiotic contaminants in water samples taken from a heavily polluted well was studied using three photocatalytic treatments: TiO2 and H2O2 (TI), Fe3+ and H2O2 (T2) and TiO2, Fe3+ and H2O2 (T3). The water samples were concentrated by solvent extraction and analyzed by gas chromatography-mass spectrometry (GC-MS). The pollutants examined included a wide range of aliphatic and aromatic halogenated compounds, various types of herbicides, such as triazines, acetamides, bromouracil, halogenated hydroxy benzonitriles and urea herbicides, and also several groups of industrial organics, most of which were found to undergo photodegradation to less than 0.1 ppb. In a test of the time course of the photodegradation, in the presence of TiO2, Fe3+ and H2O2, most compounds were appreciably degraded within 3.5 h by natural sunlight, but more complete detoxification required longer exposures. Long-chain fatty acid derivatives and phthalate esters were quite resistant to all three treatment methods.