The process of aeration is used to mix, circulate, or dissolve air into a liquid or another substance.
Mechanical aeration can reduce the amount of chemicals needed to treat a body of water by providing the oxygen that bacteria need to function properly.
There are two common types of water aeration: subsurface and surface. Although subsurface aeration comes to mind first in discussions of wastewater treatment, surface aeration plays an equally important role in oxygenating liquids.
How Does Surface Aeration Work?
Surface aerators push water from under the water’s surface up into the air, then the droplets fall back into the water, mixing in oxygen. The jets of water break the surface with varying degrees of force.
There are many types of surface aeration devices, including floating aerators. When these have a high pumping rate, they can effectively mix liquids in water treatment lagoons and tanks. Often, these have low trajectory sprays, a feature that produces high oxygen transfer rates.
Other surface aeration devices include bubblers, fountains, and agitators.
Floating aerators can be used in applications such as wastewater treatment, leachate treatment, supplemental aeration, and sequencing batch reactors to release unwanted gases from the water.
Floating paddle wheel aerators are another type of surface aeration device. Their rotating blades produce strong, horizontal mixing action and create a high oxygen transfer rate through the mist created by the paddle. They can be used alone or in groups to create flow patterns in oxidation ditches, lagoons, or tanks.
How well surface aeration works depends on the amount of surface contact between the air and water. Because the equipment sits on the surface, this type of aerator is effective in introducing oxygen to the top foot or so of a body of water, depending on the type of nozzle used.
Surface Aeration Applications
Aeration is needed across a wide range of industrial applications, including the food processing and petrochemical industries, as well as pulp and paper mills. It is also commonly used to treat agricultural wastes.
Surface aerators can also be used to keep still bodies of waters circulating, healthy, and odor-free. Water features on golf courses or in public parks are a good example. These decorative water features and aquaculture ponds may have specific special needs to keep fish and plants healthy.
Factors such as heat can prove challenging to surface aeration because of higher rates of evaporation, which can have an adverse effect on some applications.
Many aeration technologies are currently available on the market, and each is designed to address a specific challenge or range of challenges. Contact Fluence for more information on how surface aeration can work for you.