Ozonising a water containing even low levels of Bromides can result in
a serious problem related to the Bromate ion and its carcinogenicity:
the current WHO guidelines for the drinking water are fixing a limit
for Bromates presence at 3 μg/l (against previous limit of 10 μg/l,
valid until few years ago).
An accurate control of the
dissolved ozone concentration: operating at a stable concentration
around 200 ppb (plus - minus 100 ppb) will guarantee to minimize the
Bromates formation thanks to the low kinetic of the oxidation process.
Bottlers with Bromates related problems on their mineral water
lines are often using very simple water ozonising equipments with very
simple ON-OFF ozone gas production unit completely disjointed from the
ozone-water mixing system and without any kind of control on the
dissolved ozone concentration is often used in those cases.
Unfortunately a bottling line is a discontinue system and, when the
line stops, the ozone concentration can probably rise even above 1,5
mg/l with very high contact times causing the complete oxidation of
Bromides into Bromates.
To guarantee a steady ozone
concentration to the bottled product even in case of line’s stops or
format changeover (flow rate fluctuations) ENVIROTECH standard water
ozonising equipments with an highly accurate dissolved ozone analyser
are provided with a full automatic control of the dissolved ozone
concentration according to bottler’s set point and water flow rate.