What is wet catalytic oxidation?

Wet oxidation, abbreviated as WAO, was first proposed by American F.J.Zimmermann in 1944. Used in papermaking black liquor, it has obtained many patents, so it is also called zimmermann method. Under high temperature and high pressure, the organic matter in wastewater is oxidized into carbon dioxide and water by oxidant, thus achieving the purpose of removing pollutants. Subsequently, the oxidation method developed rapidly, and its application scope was further expanded from recovering useful chemicals and energy to treating toxic and hazardous wastes.

Wet oxidation is generally a technology that oxidizes dissolved or suspended organic matter or reduced inorganic matter in water at high temperature (150-350℃) and high pressure (5-20MPa) to generate small molecular substances such as carbon dioxide and water. Generally, there are two steps: ① the mass transfer process of oxygen in air from gas phase to liquid phase; ② Chemical reaction between dissolved oxygen and matrix.

Catalytic wet oxidation technology: In order to improve the treatment efficiency and reduce the treatment cost, wet oxidation technology based on WAO and using efficient and stable catalyst, namely CWAO, was derived in 1970s.

Adding catalyst into the traditional wet oxidation treatment system reduces the activation energy of the reaction, thus reducing the reaction temperature and pressure without reducing the treatment effect. Using oxygen or air as oxidant, the dissolved or suspended organic matter or reduced inorganic matter in water is oxidized to produce small molecular substances such as carbon dioxide and water.