Variations on the basic schemes of creating hydroxyl radicals using UV and either ozone or peroxide have been
combined to use all three components. Spartan can offer this combination of technologies if necessary, but normally this
type of system is not required.
The idea of adding the oxidants at different points of the process or in different combinations is designed to improve the efficiency of the overall oxidation process. The overall idea is to improve both the economy of hydroxyl radical production as well as the economy of hydroxyl radical use. As a simple example, if one of the species that one wants to oxidize is readily oxidized by peroxide, it does not make economic sense to oxidize it using and expensive species such as the hydroxyl radical. Instead, by introducing peroxide first, one can oxidize these easier to oxidize species prior to introduction of the hydroxyl radicals. Excess peroxide can then be reacted with UV or ozone to form the hydroxyl radicals for the attack of the more difficult to oxidize species. Another potential reason for the combination is the addition of hydrogen peroxide to the UV/ozone combination results in a greatly increased efficiency of oxidation. Such increased efficacy reflects a synergistic effect which may be related to the intermediate production of ozone or HO2 radicals which set in motion rapid oxidation reactions. In any event, benefits have been observed in the removal of organic compounds from water in lab, pilot and commercial applications.