Projects,/ SOI Zwolle centrate pretreatment for feed to AMX

SOI Zwolle centrate pretreatment for feed to AMX

2022 -2023

Client: Waterschap Drents Overijsselse Delta

Keywords: centrate, Anammox, pretreatment, drum filter, pilot


Project description

At WwTW Zwolle, the Netherlands, an Anammox process is applied to treat the nitrogen rich waste stream from the sludge dewatering. Sludge is dewatered using two centrifuges. The centrate is fed into the Anammox reactor. Removing most of the anorganic substances from the centrate, prior to feeding it into the reactor, will lead to a more reliable and stable biological process. A pilot using a drum filter is executed to determine the basis of design.

Drum filter with spray nozzles


Pilot set -up


“If in doubt, try it out”. With a small package unit we could simulate the performance of the plant, and try different operational settings: throughput, mesh width, washing frequencies and the characteristics of the residue. Also the operational staff involved were able to familiarize with the technology. The final solution leads to a serial “roughing” screening of the centrate, using the existing screen and the implementation of a fine screening drum filter.


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And we highly appreciate their feedback!

“Through collaborative working with Brightwork a better understanding has been gained into continuous moving bed sand filtration systems. Using the novel Sand Cycle technology, developed by Brightwork from the Netherlands, has given rise to better understand the relationship between sand bed movement and filtration efficiencies.  Paving the way to higher removal efficiencies, towards optimized real-time load-based operations.”

Gareth Medley

Conway Engineering

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