Do you know Wet Catalytic Oxidation?

Wastewater Treatment By Air Oxidation is a kind of chemical treatment method for wastewater. It is a method of using strong oxidants to oxidize and decompose pollutants in wastewater to purify wastewater. It has become an important method for the treatment of bio-degradable organic toxic pollutants. Pesticide, papermaking, electroplating and printed board, pharmaceutical, hospital, mine, landfill leachate and other wastewater treatment have been applied.

Wastewater Treatment By Air Oxidation

Wet oxidation

Wet Catalytic Oxidation uses high temperature (125-320 ℃) and high pressure (0.5-20MPa) to oxidize organic substances in wastewater to carbon dioxide by using oxidants (originally air or oxygen, but also other oxidants such as O3, H2O2, etc.). And water or small molecule organic matter, so as to achieve the purpose of removing pollutants. In the 1970s, Catalytic Wet Air Oxidation (CWAO) was proposed based on the traditional wet oxidation method. It added a suitable catalyst on the basis of the WAO process, which reduced the reaction temperature and pressure and improved the organic matter. The oxidation rate improves the oxidation efficiency, which reduces the operating costs and equipment investment.

Compared with conventional methods, wet oxidation has a wide range of applications, high processing efficiency, very few secondary pollution, fast oxidation rate, recyclable energy and useful materials. Therefore, it has been widely valued by scientific researchers around the world. A promising water treatment method.

The traditional WAO has obtained mature industrial applications, but due to its inherent defects, it is still limited in practical application. WAO is generally carried out under high temperature and high pressure conditions. It requires high equipment materials (high temperature, high pressure and corrosion resistance), and the one-time investment cost of the equipment is large. WAO is only suitable for small-flow high-concentration wastewater treatment, and it is not economical for low-concentration large-volume wastewater. In addition, even at very high temperatures, the removal effect of WAO on certain organic substances in wastewater such as polychlorinated biphenyls and small molecule picolinic acid is not ideal, and it is difficult to achieve complete oxidation. CWAO overcomes the shortcomings of traditional WAO to a certain extent, but it also needs a lot of research and development in the development of broad-spectrum high-efficiency catalysts, improvement of reactor materials, structure and operation methods.

Advantages of wet catalytic oxidation:

(1) It has a wide range of applications, can effectively oxidize various types of high-concentration organic wastewater effectively, and has a good treatment effect. Under appropriate temperature and pressure conditions, the COD treatment rate can reach more than 90%.

(2) The oxidation rate of organic pollutants is fast, generally only 30 ~ 60 minutes, less secondary pollution and lower energy consumption.

(3) Waste heat and certain substances can be recycled.