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.
