The paper focuses on the modelling of bromate formation. An axial dispersion model was proposed to integrate the non-ideal mixing, mass-transfer and a kinetic model that links ozone decomposition reactions fromthe Tomiyasu, Fukutomi and Gordon (TFG) ozone decaymodelwith direct and indirect bromide oxidation reactions, oxidation of natural organicmatter and its reactionswith aqueous bromine. To elucidate the role of ammonia an additional set of reactions leading to bromamine formation, oxidation and disproportionation was incorporated in the kinetic model. Sensitivity analysis was conducted to obtain information on reliability of the reaction rate constants used and to simplify the model.

Validation results of a theoretical model that describes the formation of bromate during ozonation of bromide-containing natural waters are presented. An axial dispersion model integrating the nonideal mixing, mass-transfer and a kinetic model that links ozone decomposition reactions from the Tomiyasu, Fukutomi and Gordon ozone decay model with direct and indirect bromide oxidation reactions, oxidation of natural organicmatter and reactions of dissolved organics and aqueous bromine was verified. Themodel was successfully validated with results obtained both at a laboratory and a full scale. Its applicability to different water supply systems was approved.

Bromate is well known by-product produced by the ozonation of drinking water; the allowed concentration for human consumption has to be regulated to few μg/dm3 ranges. A method using ion chromatography has been developed, which will quantify bromate on this level, even in the presence of high levels of common anions such as chloride, nitrate and sulphate. The present article presents results of study of bromate determination in drinking water by two ion chromatographic methods. First was a direct method according to ISO 15061 with conductivity detector and limit of detection 4,5 μg/dm3. The second was new post-column derivatization reaction to produce tribromide ions, which was detected by UV detector. Limit of determination in this method was 0,5 μg/dm3. Both these methods are suitable to determination of bromate anions, because acceptable contents of bromate in drinking water in UE countries are 10 μg/dm3.