Aeration

Aeration is a means of bringing air into strong contact with water. The purpose of aeration is to dissolve oxygen in the air into the water or to expel unwanted gases and volatile substances from the water into the air. In other words, it is a means of facilitating the exchange of matter between gas and liquid. It also has some other important functions, such as mixing and stirring. Oxygen in the air is transferred to the water by aeration, and oxygen is transferred from the gas to the liquid phase by mass transfer. The theory of mass transfer and diffusion is mostly applied to the double membrane theory proposed by Lewis and Whitman.

Aeration principle

According to the double film theory, there are gas film and liquid film on the "gas-water" interface, and air and liquid flow outside the gas film and liquid film, which belongs to the turbulent state. The air film and liquid film belong to the laminar flow state, there is no convection, and under certain conditions will appear pressure gradient and concentration gradient. If the concentration of oxygen in the liquid film is lower than the saturation concentration of oxygen in the water, the oxygen in the air will continue to spread inward through the liquid film into the water body, so the liquid film and the gas film will become the obstacle of oxygen transfer, which is the double film theory. Clearly, the most effective way to overcome the liquid film barrier is to rapidly transform the "gas-liquid" interface. Aeration stirring is exactly so, the specific approach is: to reduce the size of the bubble, increase the number of bubbles, improve the liquid turbulence degree, increase the installation depth of the aerator, and extend the contact time between the bubble and the liquid. Aeration equipment is widely used in sewage treatment based on this practice.

Practical application

Rocker arm microporous aerators are widely used in primary biochemical systems with heavy production loads and poor sewage quality because of their high aerobic utilization rate and convenient maintenance. The stationary dynamic aerator is generally used in the secondary biochemical system with lower production load and better sewage quality because of the characteristics of low aerobic utilization rate but long-term maintenance, maintenance difficulty, and long service life.

Production Introduction

Petrochemical, printing and dyeing, textile, food, brewing, pharmaceutical, tanning, papermaking, coking, steel mills, power plants, and many other enterprises industrial wastewater and urban sewage.