92-07: Biocidal Aspects of Ozone for Cooling Water Treatment - Probable Impacts

Some ozone suppliers claim Biocidal benefits of ozone throughout the cooling systems. Yet the short half-life of ozone coupled with the high ozone demands of cooling waters make it unreasonable to expect that any residual ozone will be present shortly after its application. Most cooling intake waters contain bromide ion (from traces up to 1.5 mg/L). Oxidization of bromide ion with ozone is known to produce the hypobromous acid/hypobromite ion (HOBr/Obr) couple, a stable biocide that survives after ozone residuals decay. The known chemistries of ozone oxidation of bromide ion will be discussed and a German cooling water treatment system based on these chemistries will be described.