ABSTRACT
The majority of chemical as well as a few physical water disinfection methods, such as UV and cavitation, are known to generate hydroxyl radicals that are the sole disinfecting species. Therefore, an increase in their generation would naturally augment the disinfection process. Several oxidation techniques are based on this principle, and these are known as the advanced oxidation processes (AOPs). Hybrid techniques employ a combination of various oxidation techniques, which results in an accelerated production of hydroxyl radicals to affect water disinfection. The hydroxyl radical is a powerful oxidising radical, second only to uorine (Paul and Canter, 1990), and is therefore appropriate to use in water treatment, as it does not produce any unwanted residuals. Advanced oxidation systems generally combine ozone, hydrogen peroxide, and ultraviolet radiation, for example, O3 and H2O2, O3 and UV, and H2O2 and UV.
