Oxygen injection is a technique used to promote the growth of beneficial aerobic bacteria in sludges and liquids. There are a number of settings in which oxygen injection may be used, usually with the goal of getting the bacteria to do some sort of work which cannot be performed by humans. Bacteria can be highly efficient and very effective workers in the right conditions, making this technique very useful in settings where it is appropriate.
In the oxygen injection process, pure oxygen is introduced into the sludge or fluid being treated. This raises the dissolved oxygen content in the fluid, promoting bacteria which need oxygen to survive. These bacteria are usually native to the material, although they can also be introduced, and they will multiply quickly in the oxygenated conditions, making their work go much faster.
One use for oxygen injection is in the treatment of activated sludge from sewer plants. In this case, the bacteria are used to break down the sludge as part of the wastewater treatment process. To speed things along, oxygen injection can be used to maintain a highly oxygenated environment for the benefit of the bacteria the wastewater treatment company wants to promote. Oxygen injection systems can be built into the plant, or added later.
This technique can also be used in environmental cleanup, especially in cases of contaminated groundwater. One technique commonly used to remove things like petroleum from groundwater is to introduce bacteria which can feed on the petroleum, breaking it down and clearing the water of contamination. In oxygenated water, these bacteria will work much more quickly and effectively. Oxygen injection is used to disperse oxygen widely throughout the contaminated water, allowing the bacteria to do their work.
One benefit to this process is that it does not introduce harmful byproducts. The oxygen is utilized by the bacteria without the creation of additional environmental problems which might need to be disposed of. The accidental creation of secondary problems in the process of environmental cleanup has been an issue of concern historically in the environmental community.
It is possible to rent oxygen injection systems, with companies usually sending out a technician to supervise their use. Companies which handle environmental cleanup, especially if they deal with groundwater, may purchase and maintain their own systems because this can be more cost effective than rental in the long term, and it may be an advertising point, as it allows a company to respond quickly to an environmental disaster with all the equipment it needs.