Fine Bubble Aeration in Wastewater Lagoons—Pros and Cons

author: lisa

2026-01-23

Fine Bubble Aeration in Wastewater Lagoons—Pros and Cons

Installed at the bottom of the lagoon, fine bubble aerators release tiny bubbles that slowly rise to the surface of the water. These thousands of tiny bubbles collectively have a very large surface area. As a result, they can efficiently and effectively transfer oxygen to the entirety of the water column.
we will attempt to give a full, unbiased breakdown of fine bubble aeration in wastewater lagoons.

The 3 Main Types of Fine Bubble Aerators

1.Membrane Disk Diffusers – Your typical membrane disk diffusers are going to be between 9″ and 11″ in diameter. They will be composed of EPDM rubber, mounted on a base plate, and will screw into a header or lateral. The EPDM will expand as air is pumped through it, which will open hundreds of small perforations. This results in the release of thousands of fine bubbles (less than 2mm in diameter).

2.Tube Diffusers – Most tube diffusers are made from a rigid ceramic or hollow plastic cylinder. These cylinders are long and thin, and are surrounded by EPDM rubber. The air is transferred and released in the same manner as the disks, except tube diffusers generally offer more surface area than disks, and thus can release more fine bubbles.

3.Perforated Tubing – This type of diffuser, sometimes referred to as “Bubble Tubing,” is generally composed of LDPE with slits or holes punched in it. These small holes then leak air at pressurized airflow. However, this type of LDPE diffuser does not expand and contract to open these perforations in the same manner that the tube and disk diffusers do.

The Benefits of Fine Bubble Aeration

1.Energy Efficiency – Boasting an Standard Aeration Efficiency (SAE) of 4–7 lbs O2/hr/hp-wire, very few aeration technologies can compete with the fine bubble in terms of energy efficiency. In many cases, switching from alternative lagoon aeration technologies, such as surface aeration or coarse bubble aeration, can save anywhere from 40–60% (or more) on energy costs.

2.Improved Dissolve Oxygen levels – Similarly, fine bubble aeration can also achieve Standard Oxygen Transfer Efficiencies (SOTE) of 1.8–2.2% per foot of submergence. Any other system on the market will have a very difficult time matching this type of oxygen transfer efficiency performance. If you’re installing a fine bubble aeration system in your wastewater lagoon, it’s safe to expect noticeable increases in dissolved oxygen (DO).

3.Fewer motors to maintain – In comparison to surface aerators, a fine bubble aeration system will likely have fewer motors to maintain. For example, where a typical surface aeration system may have 5–10 surface aerators, a fine bubble system will typically only have 2–3 blowers. Moreover, these motors are more easily accessible as they are onshore. This cuts down on maintenance time, materials, and hassle.

The Disadvantages of Fine Bubble Aeration

Fouling & Clogging – Any fine bubble aeration technology is susceptible to bacterial fouling. This is the process whereby bacteria form on the surface of the diffuser and impinge upon the orifices. This causes increased back-pressure and wear on the blower, thereby increasing energy and maintenance costs.In order to maintain system performance, operators must clean and/or replace fine bubble diffusers on a scheduled basis.

The Trend Towards Fine Bubble Aeration

Similar to other industries, wastewater treatment must advance with the times. With the current worldwide initiative to “Go Green,” and to find energy efficient, environmentally friendly solutions, fine bubble aeration fits in perfectly. There is some necessary maintenance, such as periodic cleaning, but maintenance is a part of any wastewater lagoon aeration system. Its energy efficiency and ability to improve dissolved oxygen levels tend to outweigh the negatives. For this reason, we’ve recently seen a worldwide trend of wastewater treatment facilities switching from surface aeration (and other wastewater lagoon treatment alternatives) to fine bubble aeration.

Please don’t hesitate to contact us with questions or comments. We’ll be happy to dig into more details.