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Energy recovery from wastewater

Resource recovery from wastewater

Wastewater management


Turning wastewater into green energy

10. September 2013
ejby mølle

Solution provider

VCS Denmark

VCS Denmark (VandCenter Syd in Danish) is one of the largest water and wastewater utilities in Denmark – and a frontrunner in the water sector.

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Today, the company is energy positive: producing more energy than we consume. This result has been achieved by:

  • Optimizing the wastewater facility’s existing infrastructure
  • Enhancing nutrient reuse
  • Maximizing biogas extraction to produce electricity and heat

In this case, seeing wastewater as a resource is key. Therefore, we now consider our wastewater treatment plants to be water resource recovery facilities.

Recovering water resources: The Ejby Mølle plant

VCS Denmark’s largest facility, the Ejby Mølle plant, is a technological forerunner in the field of treating wastewater, increasing efficiency, and producing energy.

At the plant, renewable energy is produced by turning sludge into biogas, which is then transformed into heat and electricity. Digesters and buildings are heated by waste heat from gas motors, and surplus heat production is sold to the regional district heating utility.

Net energy production is the result of years of continued efforts in all parts of the wastewater treatment process. As consultants we share our knowledge with other utilities that want to embark on a journey towards recovering resources. You can read more technical details, facts and figures about our results in this article from Source Magazine.

The Ejby Mølle plant treats wastewater from two Danish municipalities and has a capacity of 385,000 person equivalents (PE). The plant contains five major elements:

  • Mechanical treatment unit
  • Activated sludge unit
  • Trickling filters for treating stormwater
  • Sand filter
  • Sludge dewatering unit

After treatment, an aeration unit ensures a high oxygen level in the discharged water.

VCS Denmark holds more than 160 years of operational experience as a water utility  and is known for finding innovative technical solutions. We share our know-how with utilities around the world.

We are an active partner in 3VAND - a strategic collaborative partnership consisting of the leading water utilities in Denmark: HOFOR, BIOFOS, Aarhus Vand and VCS Denmark.