Diffused Aeration Process

Aeration is used extensively for the biological (biochemical?) oxidation of both domestic and industrial organic wastes. In wastewater treatment, the function of aeration is to introduce air into the water through the most effective and least costly methods that will increase oxygen transfer (dissolved oxygen) in the wastewater.

Aeration to Maintain an Aerobic Condition

Diffused Aeration helps maintain an aerobic condition, with a basic purpose of improving water quality for subsequent reuse. Aeration can bring about the physical removal of taste- and odor-producing substances, such as hydrogen sulfide (H₂S) and other volatiles and the chemical removal of metals (iron, manganese), gases (hydrogen sulfide), and other compounds (organics and inorganics) through oxidation and settling.

Mechanical Aerators

Mechanical aerator can either be submerged or surface designs, depending on whether certain systems require pure oxygen to be introduced from the aeration tank bottom.

• Vertical Axis Aerators – induce updraft wastewater flow or reverse downdraft flow
• Horizontal Axis Aerators – spray water across wastewater surface to agitate water and to entrain air into the water

Diffused Aeration Devices

In diffused aeration, submerged devices release air or oxygen into the wastewater. As bubbles rise through the wastewater, (1) oxygen is transferred from a gaseous state to a liquid state – thus adding dissolved oxygen (DO) to the water and (2) they keep the microorganisms suspended, so they do not settle out. The longer these particles are suspended and maintain contact with the DO, the more waste solids they can consume and break down.

To achieve proper oxygen transfer efficiency (OTE), different devices can be added to wastewater treatment processing systems that will facilitate and control aeration. There are three types of diffused aeration systems; these are typically classified by the physical characteristics of the equipment. Please note that wastewater treatment systems may use one or more different types of aeration devices.

• Surface Aerators
  • Brush type
  • Propeller type
• Diffused Aerators
  • Fine Bubble Diffusers*
  • Coarse Bubble Diffusers*
  • Holey Pipes
• Hybrid Devices
  • Jet Aerators
  • Turbines

* Bubble diffusers can come in various shapes and sizes, such as discs, tubes, domes, and plates.

Diffused Aeration Performance for Enhanced Biological Growth

Aeration performance through diffused aeration has advanced dramatically in more recent years.

To keep your plant running in peak operating condition 24/7, 365 days a year, we apply the latest in diffused aeration technology — to deliver aeration and cost efficiencies, along with unsurpassed reliability. Call Mooers to start improving your facility’s performance today.