Municipal Sludge Dewatering Trials save significant operating costs

The HUBER Screw Press Q-PRESS® 280 trial equipment has been busy over the last few months. Although it has been much harder and taken longer to organise than usual, we at HUBER Technology consider ourselves very fortunate to have been able to conduct business like this during the COVID pandemic.

Trial 1

The first trial was at a site in the North East of England. The site has a Population Equivalent of 61,469 and a full flow to treatment of 463 l/s and which presently uses a Gravity Belt Thickener (GBT) to mechanically thicken the Surplus Activated Sludge (SAS) produced on site, which is then mixed in 2 storage tanks with the manually decanted indigenous primary sludge. Due to varying transfer volumes and times, the ratio of SAS to Primary in the sludge tanks can fluctuate significantly.

Results summary

Average Incoming DS


Average Cake DS


Trial 2

This was at a WwTW site that treats effluent from a Population Equivalent of 19,615 with a dry weather flow of 202 l/s and full flow to treatment of 505 l/s. Primary industries in the catchment are food manufacturers.

The treatment on site produces roughly 320 m3/d of primary sludge from the Kaldnes moving bed bio-film process, which uses aeration and floating plastic media, and around 195 m3/d of Surplus Activated Sludge (SAS). The Kaldnes sludge was considered a “tricky” sludge to subsequently process.

Results summary

Average Incoming DS


Cake DS using enhanced mixing



These results demonstrate that the Q-Press® provides a viable alternative to centrifuges with the following benefits

  • 80% power reduction compared to centrifuge
  • 30% reduction in poly compared to belt presses
  • 6 fold reduction in maintenance compared to centrifuge
  • Reliable –

    • single moving part
    • slow rotation

  • Reduced operator interventions
  • Filtrate drains by gravity
  • Removable outer case for easy maintenance


For full details on the trials and more performance results please contact Rachael Harvey at Rachael.harveyhuber.couk


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Products in use and related solutions

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