In a report published on 20 October 2026, SUEZ S.A. was selected by Kalundborg Forsyning A/S to design and deliver a new quaternary treatment stage at the Kalundborg Central Wastewater Treatment Plant in Denmark, an upgrade intended to reduce micropollutants in treated wastewater discharged into Storebælt. ChemEngOnline
The project will also increase treatment capacity, with the selected configuration comprising two ozone-injection lines supplied by three ozone generators, eight granular activated carbon filters and digital optimization technology. ChemEngOnline
Key takeaways
- Kalundborg Forsyning selected SUEZ to design and deliver a new quaternary treatment stage at the Kalundborg Central Wastewater Treatment Plant. ChemEngOnline
- The installation is intended to reduce micropollutants in treated wastewater discharged into Storebælt and increase the plant’s treatment capacity. ChemEngOnline
- The treatment train combines two ozone-injection lines, three ozone generators, eight granular activated carbon filters and digital optimization technologies. ChemEngOnline
- The contract will be executed over three years, and SUEZ described the installation as designed to support long-term treatment performance while optimizing operating costs and carbon performance. ChemEngOnline
- The project expands SUEZ’s portfolio of advanced wastewater treatment references in Denmark, where the company has six municipal and industrial plants dedicated to micropollutant removal in operation or under construction. ChemEngOnline
What changed at Kalundborg
Kalundborg Forsyning selected SUEZ to design and deliver the quaternary treatment stage at its central wastewater treatment plant, according to a report published on 20 October 2026. ChemEngOnline
The installation is intended to reduce micropollutants in wastewater discharged into Storebælt, while also increasing treatment capacity and supporting compliance with stringent environmental requirements. ChemEngOnline
The selected process combines two ozone-injection lines, supplied by three ozone generators, with eight granular activated carbon filters. Digital optimization technologies will support operation of the new stage, which is designed to reduce operating intervention while optimizing operating costs and carbon performance. ChemEngOnline
Contract and regulatory context
The contract will be executed over three years and builds on SUEZ’s stated 35-year presence in Denmark and more than 10 years of experience with micropollutant treatment in the country. ChemEngOnline
The revised European Urban Wastewater Treatment Directive introduces requirements for micropollutant removal through quaternary treatment. EU member states must transpose the directive into national law by July 2027, with progressive implementation targets thereafter. ChemEngOnline
Specification read
The scale of the Kalundborg upgrade was not reported: the source gives no design flow in m³/day, population-equivalent loading, existing plant capacity or post-upgrade capacity, so those buyer-unit values cannot be calculated without inventing figures. It also does not provide the plant’s BOD or COD levels or a unit cost for the installation. ChemEngOnline
For a conventional municipal wastewater train, the reported work bears directly on the advanced-treatment stage after preliminary, primary and biological treatment; the supplied source does not identify the plant’s upstream screening, primary, biological, tertiary or disinfection configuration, so those process stages cannot be confirmed for Kalundborg. The quaternary package itself comprises ozone injection followed by granular activated carbon filtration, with digital optimization for operation. ChemEngOnline
If your plant resembles Kalundborg’s in needing micropollutant removal, additional treatment capacity and support for stringent environmental requirements, this project indicates a combined ozone-and-activated-carbon quaternary package with digital operation; the source does not provide the flow, BOD/COD or cost inputs needed to judge suitability. ChemEngOnline
For broader municipal equipment context, see HydropureWater’s municipal wastewater solutions and industries served.
FAQ
What treatment process was selected for the Kalundborg upgrade?
The selected stage combines two ozone-injection lines, supplied by three ozone generators, with eight granular activated carbon filters. Digital optimization technologies will support operation, and the installation is intended to reduce micropollutants while increasing the plant’s treatment capacity. ChemEngOnline
How long will the Kalundborg contract take to execute?
The contract will be executed over three years, according to the report published on 20 October 2026. The source does not provide separate installation, commissioning or equipment-delivery dates, so those milestones cannot be stated from the available information. ChemEngOnline
What does the project cost?
The source does not report a contract value, unit price or estimated operating cost. It says the installation is designed to optimize operating costs and carbon performance, but it provides no financial figure that can be used for budgeting or a supplier comparison. ChemEngOnline
How should a utility assess an ozone and activated-carbon supplier?
The Kalundborg selection points to an integrated package comprising ozone generation and injection, granular activated carbon filtration and digital optimization. Buyers would still need supplier proposals and site-specific data because the source does not state the design flow, contaminant concentrations, treatment targets, guarantees or delivery schedule. ChemEngOnline
