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Sludge Dewatering Centrifuges: How Do They Work?

Sewage disposal is one of the most consequential ecological processes in the United States, with huge implications for the health of individuals, communities, and the natural world.

For generations, the wastewater treatment industry has prioritized methods to stop the spread of waterborne diseases while finding safe ways to release solid, organic wastes back into the environment. There are robust systems and infrastructures in place to facilitate these processes. One of the most critical technologies is the sludge dewatering centrifuge. Simply put, sludge dewatering centrifuges play a vital role in municipal wastewater management, which means they benefit all of us.

What is a Sludge Dewatering Centrifuge?

Given the significance of sludge dewatering centrifuges in our everyday lives, it benefits all of us to know a little bit more about how these systems work.

Imagine a large cylinder, or bowl, which spins at a very fast speed. This motion causes wastewater solids to become separate from the liquid. In other words, it removes water altogether and leaves behind a “cake” of solid waste. This process means that waste storage takes up less space, and waste transport is more cost-effective.

The Pros and Cons of the Centrifuge Method

Though the centrifuge method is widely considered to be the superior option for separating solid and liquid wastes, it’s not the only method, and neither is it faultless. Indeed, there are both some pros and some cons to consider.

The Pros of Sludge Dewatering Centrifuges

  • By turning heavy and voluminous waste into something quite a bit lighter and more compact, the centrifuge method can reduce waste transport costs by as much as 75 percent.
  • Centrifuge equipment may be built close to any wastewater treatment facility, making it convenient and cost-effective.
  • The cakes produced via this method can be easily placed into a landfill, or mixed with other green waste and then turned into compost.
  • The water that is removed via centrifuge can be used in industrial applications or for irrigation.

The Cons of Sludge Dewatering Centrifuges

  • This method does have a fairly high level of energy consumption, which has prompted criticism from some green activist groups.
  • The process is very noisy, too.
  • Most wastewater treatment facilities will want to have a standby unit, to ensure maximum uptimes.
  • While maintenance needs are minimal, they do require skilled specialists.


The most common alternative to the centrifuge method is what’s known as a filter press. This method feeds the wastewater into a hopper, where the waste is then pressed between two pieces of filter cloth. Rollers are then used to remove the fluid from the dewatering process. The solids are placed into a container while the filtrate is sent down a drain.

Ultimately, centrifuges provide cakes with less liquid content, and are also less expensive. With that said, filter press systems can be faster to start up and shut down, they run more quietly, and maintenance can be a bit easier.

Questions About Sludge Dewatering?

With any additional questions about different sludge dewatering methods, feel free to contact PHS at your convenience.