What Are the Parameters of an Extended Aeration System?

January 4, 2022

Does your wastewater treatment plant need an extended aeration process? Extended aeration is part of the activated sludge process, in which suspended microorganisms are used to break down the sludge. Aeration can be “conventional rate,” which is achieved through mechanical means, or extended, which uses diffused aeration.

Here’s what you need to know about the extended aeration process.

What is extended aeration vs. activated sludge?

Extended aeration treats the contaminants in wastewater by introducing diffused air into the aeration tank. The wastewater is sent to a 24-hour detention tank, then a four-hour final settling tank. Aerobic bacteria feed on the solids in wastewater, breaking them down and oxidizing them during the initial detention period.

In the settling tank, the remaining oxidized solids separate from the rest of the effluent. Even though the aeration process is lengthier, it won’t get rid of all the solid matter in your wastewater. The separated and treated liquid is removed for further use or clarification, while the settled solids are pumped out of the tank and back into the aeration system.

Activated sludge is the settled solids that are pumped out of the final settling tank. They are considered a biomass that can be used to introduce aerobic bacteria to effluent. The sludge, therefore, is a valuable byproduct of the extended aeration process.

Benefits of an extended aeration system

There are many benefits to opting for an extended aeration process. These include:

  • An efficient way to treat water: Wastewater must be treated properly in order to rejoin municipal water supplies. Extended aeration takes advantage of naturally occurring aerobic bacteria and allows it to break down the solids in wastewater. It’s safe, efficient and uses natural processes to treat effluent.
  • Flexible: Wastewater volume is not always consistent. The extended aeration process can handle flow fluctuations, so your processes won’t slow or back up.
  • Low sludge production: Extended aeration produces relatively low levels of sludge, since the extended period allows bacteria to break down more waste product.
  • Meets regulatory requirements: When treating wastewater, facilities must meet all state and federal regulatory standards. Extended aeration systems are designed to meet or exceed all regulatory requirements.
  • Easy to install and maintain: Generally, extended aeration systems are very simple to install and operate. You’ll have relatively low maintenance levels compared to other wastewater treatment processes and equipment.
  • Low operating costs: Finally, extended aeration offers relatively low operating costs, so your wastewater treatment facility can handle larger volumes at a reasonable operating cost.

There are several different ways you can achieve extended aeration—as long as you have an aeration tank and final settling tank, you can introduce air to the wastewater in whichever way works for your particular plant.

If you’re not sure whether you should add an extended aeration system to your wastewater treatment plant, call the team at Enviro-Line Co., Inc. today. We can help you design and install a system that will work with your existing facilities, and expand your operations. Reach out to us today to get started.

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