One of several combination oxidation processes. Advanced chemical oxidation processes use (chemical) oxidants to reduce COD/BOD levels, and to remove both organic and oxidizable inorganic components. The processes can completely oxidize organic materials to carbon dioxide and water, although it is often not necessary to operate the processes to this level of treatment.

AOP comprises the usage of secondary oxidants and involves the formation of hydroxyl radicals. These highly reactive species can be brought by oxidants in amalgamation through the usage of ultraviolet sterilization. Hydroxyl radicals are primarily culpable of deteriorating organic substances, which is ultimately what advanced oxidation processes are set to accomplish.

Hydroxyl radicals are relied upon by AOP’s due to their very strong oxidation capabilities applicable in water, including oxidizing nearly any organic compound existing in water supplies. This is often done at a circulatory and controlled speed of reaction. As a result, organic substances and contaminants are rapidly fractionalized and altered into microscopic inorganic molecules, which makes the removal process easier.