Sludge Treatment

See the big picture. We offer complete solutions for sludge treatment, from efficient digestion to energy-optimised drying.

How do you treat sludge properly? This question is of critical importance in modern wastewater treatment. On the one hand, disposal is very expensive. On the other hand, sewage sludge is a viable source of energy and nutrients. How energy-efficient or even energy self-sufficient a treatment plant actually is depends largely on the quality of sludge digestion.

Our experience in sludge treatment is comprehensive. Sludge thickening, digestion, dewatering and drying are all part of our portfolio. With our proprietary, innovative design concepts, we provide advanced sludge treatment solutions. Our LYSOTHERM® system improves the gas yield and reduces the amount of residue for disposal.

The best-possible sludge digestion enables sewage treatment plants to operate with energy self-sufficiency and in some cases with an energy surplus. This is achievable in combination with co-substrate utilisation, with energy-related improvements in the mechanical and aerobic biological wastewater treatment or with the additional use of renewable energies, such as wind power and photovoltaics. We would be happy to work with you on a tailor-made system design.

Sewage sludge digestion plant, Lingen (Ems)

Our expertise in sludge treatment

Sludge stabilisation

  • Aerobic sludge stabilisation
  • Sludge digestion, in particular: digester installation and sludge tank equipment as well as digested sludge recirculation with a mixer or via gas injection

Sludge thickening

  • Static and mechanical thickening, including centrifuges, belt thickener, drum screens

Sludge dewatering

  • Static and mechanical dewatering, including centrifuges, belt presses, chamber filter presses

Sludge drying

  • Thin Film Dryer
  • Disc dryer
  • Drum dryer
  • Low-temperature belt dryer ELODRY®

Nutrient recovery

  • Phosphate recovery from digester sludge as Magnesium Ammonium Phosphate (struvite) with EloPhos®

Sludge hydrolysis

  • Proprietary thermal pressure hydrolysis system LYSOTHERM® for excess sludge disintegraton.

Sludge mineralisation

  • Sludge mineralisation - partner of PYREG GmbH

Our Products for Sludge Treatment


Cologne-Stammheim WWTP

Sludge treatment plant

Scope of services

Mechanical and electrical equipment for the sludge treatment plant

  • Planning
  • Procurement
  • Dismantling the old sludge treatment units in the pre-/post thickener and digestion area
  • Delivery and installation
  • Commissioning

Technical data

  • Capacity 1,570,000 PE

Scope of delivery

  • 3 steel sewage silos each 250 m³
  • Replacing 5 digestion tanks mixer drives
  • 4 main heat exchangers each 8,358 kW, throughput 450,000 kg/h
  • 5 agitation heat exchangers each 580 kW, throughput 250,000 kg/h
  • Heat exchanger for disintegration with 2,585 kW, throughput 40,000 kg/h
  • Heat exchanger for co-substrates with 928 kW, throughput 80,000 kg/h


  • Drive-under silo plant mounted on steel structure
  • Installation of complete sludge treatment facilities whilst maintaining a fully operational plant

Stadtentwässerungsbetriebe Köln, AöR

December 2015 (forecast)

Contract value
EUR 5.7 million