Aeration

Aeration (also called aerification) is the process by which air is circulated through, mixed with or dissolved in a liquid or substance.

Methods of aeration of liquids

Aeration of liquids (usually water) is achieved by:

• passing the liquid through air by means of fountains, cascades, paddle-wheels or cones.
• passing air through the liquid by means of the Venturi tube, aeration turbines or compressed air which can be combined with diffuser(s) air stone(s), as well as fine bubble diffusers, coarse bubble diffusers e.g.. ecotube diffusers [1] or linear aeration tubing.

On a given volume of air or liquid, the surface area changes proportionally with drop or bubble size, the very surface area where exchange can occur. Utilizing extremely small bubbles or drops increases the rate of gas transfer (aeration) due to the higher contact surface area.

Uses of aeration of liquids

• To restrict flow of tap water at the faucet
• Production of aerated water or cola for drinking purposes
• Secondary treatment of sewage or industrial wastewater
• To increase the oxygen content of water used to house animals, such as aquarium fish or fish farm
• To increase oxygen content of wort (unfermented beer) or must (unfermented wine) to allow yeast to propagate and begin fermentation
• To dispel other dissolved gases such as carbon dioxide or chlorine
• In chemistry, to oxidise a compound dissolved or suspended in water
• To induce mixing of a body of otherwise still water
• Jacuzzi
• Pond aeration
• Diffuse air from blowers through diffusers and transfer oxygen to wastewater, e.g. ecotube diffuser

Aeration of sediments

Refers to a method of improving water quality by the augmentation of oxygen for the bacterial activities in a liquid.

Aeration of soil

Refers to the extent of air gaps in soil. Aeration commonly refers to the process of using mechanized equipment to either puncture the soil with spikes (spike aeration) or remove approximately 1"X2" cores of soil from the ground (core aeration). Spike aeration involves the use of an aeration machine with spikes up to a foot or more in length. Spike aeration is sometimes used to address drainage issues in areas with turf. Core aeration is done on turf areas as a means of reducing turf compaction, reducing thatch buildup, improving the infiltration of water/nutrients, and creating an environment where grass seed can have direct contact with the soil.

Aeration in food

Refers to the process in which air, or CO₂, is absorbed into the item. It refers to the lightness of cakes, bread and some sauces.

In wine tasting, a variety of methods are used to aerate wine and bring out the aromas. One may swirl wine in the glass, use a decanter to increase exposure to air, or a specialized wine aerator.

See also

• Lawn aerator
• Winkler test for dissolved oxygen
• Oxygen pill