Aerators for wastewater lagoons and treatment plants
Floating surface aerators supply the oxygen that aerobic bacteria need to break down organic load (BOD) in aerated lagoons, oxidation ditches and treatment basins, and keep solids in suspension. They go into a live basin on shore anchored moorings, so the plant keeps working during installation.
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Why use floating aerators on a lagoon?
A lagoon level rises and falls. Floating units ride with it, while fixed systems need bridges, grid pipework in the basin or a blower house on the bank.
Units can be added as the load grows, or moved by small boat to clear a dead zone.
Which aerator types suit lagoons?
- High speed floating surface aerators: the usual choice for aerated lagoons with a changing level
- Aspirating aerator mixers: aeration and mixing in one unit, also used for anoxic zones
- Low speed surface aerators: deep activated sludge tanks and oxidation ditches
How much aeration does a lagoon need?
As a rough guide, partial mix lagoons need about 1 to 2 W per m3 and complete mix lagoons about 5 to 8 W per m3. Real sizing works from the oxygen demand of what flows in: we size every job from your figures and show the working.
What should I send with an enquiry?
- Basin length, width and depth, and how much the level changes
- Flow and load going in, if known
- The limits in your discharge licence
- Power available at the bank
Frequently asked questions
Can aerators be added to a lagoon without draining it?
Yes. Floating aerators are lowered into the live basin and held by three or four cables to posts or anchors on the bank, so treatment carries on.
What water depth suits a floating lagoon aerator?
Floating surface aerators work best in 1.0 to 4.0 m of water, and can run in basins up to 4.5 to 5.0 m. Deeper basins need a modified unit, for example with a draft tube.