Ozone is becoming an attractive alternative chemical for drinking water disinfection due to the
resistance of waterborne pathogens such as Cryptosporidium parvum oocysts to inactivation by
weaker oxidants such as free and combined chlorine. However, the relatively high ozone doses
required for inactivation can lead to the formation of relatively high levels of bromate, a compound of
public health concern, in waters containing bromide ion. It has therefore become necessary to provide
adequate pathogen inactivation while minimizing the amount of bromate formed during water
treatment. This paper discusses an approach to achieve such optimization by characterizing the kinetics of bromate
formation by performing a limited number of laboratory-scale experiments, and developing a
mathematical tool based on this kinetic information for predicting bromate formation.
Of particular interest in this study is the role of pH in bromate formation. Experiments have been
performed with Ottawa River Water (ORW) (pH=6.1, TIC=2.9 mg/l, TOC=2.2x10-4 mg/l, [Br-]=20 ug/l) at different pH levels (pH 6.5, 7.5 and 8.4) after increasing the concentration of
bromide ion to 600 ug/L in order to determine ozone decomposition and subsequent bromate
formation profiles for this natural water. These experimental results are being used to calibrate the
mechanistic model currently under development.
Includes 57 references, table, figures.
| Edition : | Vol. - No. |
| File Size : | 1
file
, 330 KB |
| Note : | This product is unavailable in Ukraine, Russia, Belarus |
| Number of Pages : | 10 |
| Published : | 11/01/2002 |
