Extended aeration is a wastewater processing treatment designed to cut down on the volume of sludge produced. It can work well for treating waste from small businesses or other facilities with a low volume of waste production, and can also be helpful for structures with variable occupancy. The system can expand and contract to accommodate varying levels of waste production over time while still remaining functional. Numerous manufacturers produce extended aeration systems and they can be installed by many plumbers and septic experts.
The system starts with a screen to trap objects that shouldn’t move into the processing tank, such as socks and other debris that may have ended up in the waste stream. Fluid mixtures can be chopped or otherwise processed to break them up into a more uniform suspension of solids and liquids. These move into a large tank where they are aerated to promote the growth of aerobic bacteria which can eat the biological waste inside. This is similar to the system used with conventional wastewater processing, including the recycling of sludge from the bottom of the tank to keep organisms inside thriving.
In the extended aeration process, however, the mixture is aerated longer than usual. This allows organisms to keep growing and feeding, breaking down the sludge. As a result, less overall sludge is produced, limiting the volume of material produced by the system. Processed waste from an extended aeration tank can be moved to the next phase, allowing for further treatment before it is released or picked up by a company which specializes in sewage processing.
Depending on regional regulations, there may be specific requirements about sewage treatment plants and septic systems. These can determine whether extended aeration is allowed as a treatment process, and whether any additional measures need to be taken to comply with clean water laws. It is important to make sure systems are legally compliant, as otherwise people could be subject to fines or might have difficulty selling real estate, because buyers might not want to buy a structure with a sewage system that doesn’t comply with the building code.
As with other methods of wastewater treatment, extended aeration relies on a properly maintained system. Owners of such systems need to make sure they are in good working order by checking for common problems on a regular basis. If they fail to maintain the system, it might not work properly, potentially endangering the local environment. For example, the balance of bacteria in the sludge might be too low, so they cannot fully consume it, creating a high volume of raw sewage that should not be released into the surroundings.
By Mary McMahon
Ever since she began contributing to the site several years ago, Mary has embraced the exciting challenge of being a About Mechanics researcher and writer. Mary has a liberal arts degree from Goddard College and spends her free time reading, cooking, and exploring the great outdoors.