Engineered For Your Success

Sewage sludge
dewatering and
sludge thickening

Reduce cost of sludge dewatering and sludge thickening

Depending on the size of the waste water treatment plant, different waste water treatment processes are used. Sewage plant operators use Flottweg decanter centrifuges at various stages of waste water treatment to dewater and thicken sewage sludge. Sludge dewatering and thickening reduce the volume of sludge produced. After the sewage sludge is dewatered with a decanter, it can be reused or disposed of in various ways, such as agricultural use, incineration or landfill.

Thanks to decades of experience and consistent further development, Flottweg achieves an optimum dewatering rate for each type of sludge. This leads to considerable savings in transport and disposal costs.

Our decanter centrifuges for sludge dewatering and sludge thickening

Customer advantages

Economical thickening of sewage sludge

Excess sewage sludge that accumulates in the biological stages is thickened from 0.5 - 1% dry solids content to 6 - 8%. This reduces the sludge volume by 90 - 95%. The thickened sewage sludge can then be pumped into a digestion tower.

Flottweg designed the C-series OSE decanter (OSE = optimum sludge thickening) specifically for sludge thickening. It is efficient, reliable and economical. The decanter has decisive advantages over other machines.

  • High throughput rates
  • No or low polymer consumption
  • Suitable for processing mixed and primary sludge
  • Closed design to avoid odor emissions
  • Compact design, low space requirement

Cost-effective dewatering of sewage sludge

In order to transport, recycle, dispose or incinerate the dewatered sludge, it is essential that the sludge has a high dry solids content. Further important factors are the economical use of polymers, water and energy as well as reduced wear. All these success factors have been taken into account at Flottweg since the early seventies. The result of this continuous development is the Flottweg C-series HTS Decanter®. They are used in sludge dewatering for flow rates from 5 to 180 m³/h. Flottweg has developed a unique centrifuge concept specifically for the high-level dewatering of sewage sludge: the Flottweg Xelletor series. This centrifuge series combines our latest technologies and know-how from the field of sludge dewatering.

  • Highest dry solids with minimum polymer consumption
  • Consumables such as filter media and filter cloths are not necessary
  • Automatic adaptation during operation to variable feed and operating conditions via PLC or remote monitoring

Thermal Hydrolysis Process (THP)

Flottweg decanters are used by leading suppliers of THP systems. In the pre-dewatering or pre-thickening of the THP, Flottweg decanters ensure an evenly constant dry solids discharge (16.5 - 20% DS). Added to this is the low consumption of polymer flocculants.

Our modern high-performance decanters - such as the Flottweg X-series - achieve the best possible results when dewatering the sludge treated using the THP and anaerobic digestion.

Constant DS in front of the THP plant

  • Complex control systems and moving parts in the centrifuge are eliminated
  • Highest possible dry solids values during dewatering and thus low disposal costs

Achieve a higher dry solids content with Flottweg

The Dry Creek waste water treatment plant uses three Flottweg centrifuges to dewater sludge.

In this video, you can find out what this means in terms of waste water treatment plant operating costs.


Would you like to learn more about our solutions for sewage sludge treatment?

Talk to us or write us!

Similar fields of application


Treatment of Drinking Water And Waterworks Sludge


Sludge Thickening With Starch Polymer


Processing Liquid Manure

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