Water aeration

Water aeration is the process of increasing or maintaining the oxygen saturation of water in both natural and artificial environments. Aeration techniques are commonly used in pond, lake, and reservoir management to address low oxygen levels or algal blooms.

Water aeration is often required in water bodies that suffer from hypoxic or anoxic conditions, often caused by upstream human activities such as sewage discharges, agricultural run-off, or over-baiting a fishing lake. Aeration can be achieved through the infusion of air into the bottom of the lake, lagoon or pond or by surface agitation from a fountain or spray-like device to allow for oxygen exchange at the surface and the release of gasses such as carbon dioxide, methane or hydrogen sulfide.

Decreased levels of dissolved oxygen (DO) is a major contributor to poor water quality. Not only do fish and most other aquatic animals need oxygen, aerobic bacteria help decompose organic matter. When oxygen concentrations become low, anoxic conditions may develop which can decrease the ability of the water body to support life.

Any procedure by which oxygen is added to water can be considered a type of water aeration. There are many ways to aerate water, but these all fall into two broad areas – surface aeration and subsurface aeration. A variety of techniques and technologies are available for both approaches.

Natural aeration is a type of both sub-surface and surface aeration. It can occur through sub-surface aquatic plants. Through the natural process of photosynthesis, water plants release oxygen into the water providing it with the oxygen necessary for fish to live and aerobic bacteria to break down excess nutrients.

Oxygen can be driven into the water when the wind disturbs the surface of the water body and natural aeration can also occur through a movement of water caused by an incoming stream, waterfall, or even a strong flood.^{[citation needed]}

In large water bodies in temperate climates, autumn turn-over can introduce oxygen rich water into the oxygen-poor hypolimnion.^{[citation needed]}

The low speed surface aerator is a device for biology aeration with high efficiency. These devices are often in steel protected by epoxy coating and generate high torque. The mixing of water volume is excellent. The common power is going from 1 up to 250kw per unit with an efficiency (SOE) around 2 kgO2/kw. Low speed aerator are used mostly for biology plant aeration for water purification. The higher the diameter, the higher the SOE and mixing.