ABSTRACT
Ozone has been used commercially for the treatment of drinking water for nearly a century -- yet definitive studies identifying byproducts of organic and inorganic solutes have been conducted only within the past 15 years. In this paper, the author will present results of an extended literature survey on the subject, and extrapolate this information to what byproducts can be expected to form during ozonation of recycling cooling waters.
In general, organic byproducts of ozone oxidation consist of aldehydes, acids, aldehyde-acids, keto-acids, polybasic-acids, and peroxides. Some of these materials, particularly the diacids, dialdehydes, keto-acids, and aldehyde- acids, can be expected to precipitate and/or chelate with polyvalent metal ions (calcium, aluminum, iron, magnesium), thus resulting in removal from solution.
Inorganic byproducts include hydrogen peroxide, carbon dioxide (usually retained in solution as bicarbonate/carbonate ions), and nitrate ion. If bromide ion is present in the charge or makeup water, ozone is capable of rapidly converting this solute to hypobromous acid and hypobromite ion (free bromine), which can serve as an effective biocide in its own right. Free bromine also can react with organic solutes to produce bromoform and other bromine-containing organic materials. Hypobromite ion (but not hypobromous acid) can react further with ozone to produce bromate ion.
