TiO2-catalysed ozonation of raw Ebro river water

This paper presents the results obtained with heterogeneous catalytic ozonation in which raw Ebro river (Spain) water is ozonated in the presence of titanium dioxide supported on alumina as a solid catalyst at two different O3:C weight basis ratios. The influence of catalytic ozonation on the trihalomethane (THM) formation during drinking-water treatment is also studied. It is shown that using this catalyst during ozonation of the natural water allowed reductions in THM formation. Characterization of the raw, ozonated and chlorinated water was made by concentrating the sample through liquid–liquid extraction, along with the gas chromatography/mass spectrometry (GC/MS). A total of 66 different organic compounds were identified, mainly carboxylic acids, aromatics, aldehydes, ketones and alcohols. The percentage of elimination or formation levels reached during ozonation and chlorination are discussed.