It is often referred to as Zimpro (from ZIMmerman PROcess), after Fred J. Zimmermann who commercialized it in the mid 20th century.
WAO is a liquid phase reaction using dissolved oxygen in water to oxidize wastewater contaminants.
Simple organic compounds such as low molecular weight carboxylic acids and mineralized reaction products may be present in the WAO effluents.
WAO effluents are typically readily biodegradable and exhibit high values for BOD:COD ratios.
[3][4] Mixed metal catalysts, such a Ce/Mn, Co/Ce, Ag/Ce, have also been effective in improving the treatment achieved in a WAO system.
[6][7] The majority of commercial wet oxidation systems are used to treat industrial wastewater, such as sulfide laden spent caustic streams from ethylene and LPG production as well as naphthenic and cresylic spent caustics from refinery applications.
For sulfidic spent caustics, this results in a high chemical oxygen demand (COD) destruction (>90%).
High temperature systems are used to oxidize organic compounds that are present in naphthenic and cresylic spent caustics.
Almost as many systems are also used for treating biosolids, in order to pasteurize and to decrease volume of material for disposal.