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Are you considering an activated sludge process for your water treatment system? Take a look at our guide to the advantages and disadvantages of this process, as well as a quick explanation of what the process involves. Read on to learn more.


What is the activated sludge process?

The activated sludge process is a procedure in which oxygen is added to sewage. The process itself involves disturbing and agitating sewage in an environment that is rich in naturally occurring oxygen. There is no need to artificially add oxygen as the movement of the sewage is enough to create a rich oxygen mixture.

After the sewage has been agitated and disturbed, it is allowed to settle. Once settling is complete, the sewage is considered to be activated sludge as it contains the right conditions for the formation of small organisms and bacteria.

When added to raw sewage, this activated sludge will oxidize any organic solids within the sewage.

It will also help to separate any solids that have been dissolved into the sewage mixture, making filtration easier further down the line.

In an activated sewage system, the activated sludge is added to an aeration tank, along with the settled raw sewage. Following the aeration tank stage, the settled sludge is removed from the settled sludge tank, leaving behind the effluent. The settled sludge can then be reactivated before re-entering the aeration tank to repeat the process.

Advantages of activated sludge systems

There are a number of advantages to using an activated sludge system.

  • The system itself does not cost much to install, providing a good return on initial investment.
  • The effluent water produced is of high quality, as long as the sewage is of a uniform type and volume and the activated sludge stays activated.
  • It does not require much room to install and operate the system within your facility, making it a good option for applications where space may be at a premium.
  • There are very few odors or pests involved, which makes hygienic, safe, and convenient operation easy.
  • The process is relatively efficient, and there should be very little loss of pressure within the system.

Disadvantages of activated sludge systems

Unfortunately, there are also a number of disadvantages that arise when using the activated sludge process to treat sewage on a large scale.

  • There may be problems if there are any changes to the volume or type of sewage being delivered, for example, as the result of a storm surge. These problems may manifest in a reduced effluent quality.
  • The initial capital outlay may be low, but ongoing operating costs of aerating and recycling the sludge can be high. These costs will add up over time.
  • The sludge can be recycled back into the process. However, the sludge will need to be removed and disposed of after a while, and this can cause difficulties, as well as additional costs.
  • The process may not be suitable for all types of industrial wastewater, which may make it inflexible for some businesses.
  • The activated sludge may not remain activated and aerated at all times, which will severely affect the performance of the process. This means supervision is required to make sure the sludge stays activated.

There are a number of key advantages to using an activated sludge system for your facility. However, the process is not perfect, and there are a number of disadvantages that counteract these. Ultimately, the decision of whether to opt for this process or not depends on your specific circumstances.

Reach out to our team to learn more, and let us help you make your decision.