Advanced Oxidation Processes
O3 + UV –> O2 + ·O
Ozone reacting with UV forms Oxygen and Oxygen atom.
·O + H2O2 –> H2O2 + UV –> 2 ·OH
Oxygen atom reacts with water forming hydrogen peroxide which is photolyzed by UV, forming Hydroxyl radicals which is the strongest oxidant.
Water ApS has expertise in water purification systems based on advanced oxidation processes (AOPs) which have numerous advantages. The processes are called “Advanced” since the overall oxidation rate of a contaminant is faster than this of a simpler compound. AOPs consist of a combination of at least two processes which result in hydroxyl radicals (•OH) that consequently, contribute to the efficient oxidation of undesirable contaminants without producing further hazardous by-products. AOPs usually refer to a specific subset of processes that involve ozone (O3), hydrogen peroxide (H2O2) and/or UV light.
The combined treatment of ozone with UV radiation is beneficial in terms of disinfection. For UV to be most adequate, water must be pre-treated in order to decrease turbidity, which either prevents the penetration of the UV radiation or absorbs the UV energy. Ozone prior to UV makes the water more transparent as natural organic matter is degraded, soluble materials are reduced and metals precipitate. Therefore, the water visibility and consequently the ultraviolet transmittance (UVT) are increased. Thus, the UV reactor performs better, achieving high quality water. Besides that, the conjunction of ozone with UV light seems to be a robust treatment. Ozone, removing contaminants, allows to minimize the size of UV reactor.
Ozonation coupled with UV treatment, which we highly recommend for water disinfection, is not only a sufficient treatment but also economically feasible.