Lagoons · Small Wastewater Systems
What Is an Aerated Lagoon?
An aerated lagoon uses machines to add oxygen. Surface aerators throw water into the air. Diffused-air systems release bubbles below the surface. The added oxygen supports the microorganisms that break down waste. Because the oxygen does not depend on sunlight, an aerated lagoon usually needs less land than a facultative lagoon.
A partial-mix lagoon adds oxygen but does not keep every solid suspended. Some solids settle and form a bottom sludge layer. A complete-mix lagoon uses enough mixing to keep the biological solids suspended throughout the aerated basin. A complete-mix lagoon is often followed by a settling pond or cell to remove those solids.
Know which type your plant was designed to be. The normal look, solids pattern, oxygen pattern, and downstream treatment are different for each. Changing aeration without understanding the design can stir up solids, waste power, or weaken treatment.
Key point: Run an aerated lagoon according to its intended mixing and solids pattern.
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Lagoons and Small Wastewater Plants
This page comes from the course. It covers facultative and aerated lagoons, monitoring, lagoon problems, berms and liners, package plants, permits and safe work, one step at a time, with short knowledge checks and a certificate of completion.
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