Denmark’s largest UV system is now in operation

Denmark’s largest UV system is now in operation

Every hour the UV system can treat as much drinking water as almost nine Olympic swimming pools.
To secure the future supply of drinking water to Greater Copenhagen, HOFOR (Greater Copenhagen Utility) has installed Denmark’s largest UV disinfection system at a local water reservoir. The solution, constructed and installed by SILHORKO-EUROWATER, includes Wedeco UV disinfection systems equipped with energy-efficient Ecoray® UV lamps.
The modern ultraviolet light (UV) system at the reservoir will be able to treat 22 million liters (5.8 million gallons) of drinking water every hour. This makes the system the largest ever installed in Denmark, and one of the largest in Europe.
The water treatment company SILHORKO-EUROWATER installed the new UV system to replace an older system that had lower capacity and was less energy efficient.
A large part of Copenhagen’s water supply is stored in HOFOR’s huge storage facility in the northern part of the city. Here, the water from several waterworks enters and flows through a large valve structure. UV light is used to inactivate harmful microorganisms in the water.
“We needed a new UV disinfection system because the city is growing and we see a changed consumption pattern, which means that we need even greater capacity,” says Erling V. Fischer, Project Director at HOFOR. “The new UV system is therefore more than twice as large as the old one. At the same time, we took the opportunity to acquire a more modern, efficient, and sustainable technology that ensures less energy consumption, reduced need for service and maintenance, as well as increased supply security.”

Inaugurating the new UV system (from left to right): Thorbjørn Skanse Hinge (SILHORKO-EUROWATER), Peer Krueger (Wedeco), Erling V. Fischer (HOFOR), Thomas Franz (Wedeco), Tim Rindsig (Xylem Denmark), Torben Buhl (SILHORKO-EUROWATER), David Fogde (HOFOR), Thomas Drifte (HOFOR) and Michael Petersen (HOFOR).

UV light ensures safe water

The new UV solution comprises two Wedeco-brand UV disinfection systems, each of which can treat as much as 11 million liters of water per hour. This ensures ample capacity to cover consumption during peak hours in Copenhagen.

The systems disinfect the water with UV light, which provides extra assurance that the drinking water sent out to consumers is of the best quality possible. UV light inactivates bacteria, viruses and pathogens by breaking down the microorganisms’ DNA within a few seconds. Disinfection with UV light occurs without affecting the taste and quality of the water.

It was important to maintain the water supply to Copenhagen throughout the operation. Therefore, the site’s old UV system was replaced by the new solution in two stages, so that one system was kept in operation while the other was replaced.
The two new UV systems were welded to stainless foundations in advance, so that the assembly work on site was made as straightforward as possible. In practice, this meant that although the installation required cooperation between many different groups, it was successfully completed in just 18 hours and without any water interruptions.
“Everyone played their role perfectly with the installation,” says Thorbjørn Skanse Hinge, UV Product Specialist and Project Manager at SILHORKO-EUROWATER, which has been distributing Wedeco systems for 25 years. “It was a great example of how with good cooperation you can reach the goal surprisingly quickly.”

“We’re proud to see the Wedeco UV disinfection systems helping HOFOR provide safe, clean drinking water for Copenhagen, with the capacity to meet future needs,” Hinge continued. “The Wedeco K series also uses Ecoray lamps that automatically dim based on water conditions. This will help HOFOR save energy while meeting the highest water quality requirements.”

About the new UV system

  • The two UV systems are Wedeco K143 type, each with an output of 11,000 m³ (11 million liters) per hour. The daily capacity of the site’s UV solution is thus 528,000 m³ (528 million liters).
  • Each UV system has 11 rows of 12 Ecoray lamps – a total of 132 low-pressure lamps. The lamp rows can both be individually dimmed and switched off to optimize energy in relation to the current water flow.
  • The Wedeco UV systems meet the highest quality requirements for drinking water and are certified according to UVDGM (USEPA).

Learn more about Wedeco UV disinfection systems

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