More than 11,000 Aerostrips Aerate Copenhagen’s Wastewater

The two largest wastewater treatment plants in the region around Copenhagen will in future be completely converted to fine bubble diffusers from the Austrian company AQUACONSULT Anlagenbau GmbH. This means that from May 2025 the wastewater of the Danish capital will be completely treated by efficient AEROSTRIP diffusers and considerable energy savings will be achieved.

The Project

Traiskirchen, May 13, 2022: The AEROSTRIP diffusers from the Austrian company AQUACONSULT Anlagenbau GmbH is part of an enormous retrofit project of the main wastewater treatment plants in the Greater Copenhagen area. Starting in June 2022, 9,660 strip diffusers from Aquaconsult were installed at the region’s largest wastewater treatment plants, Lynetten and Damhusaen, by May 2025, treating the wastewater of 1.4 million people. All the wastewater of the Danish capital will thus be aerated by AEROSTRIPs in the final stage of expansion.

The success story began back in 2015 at the wastewater treatment plant in Avedøre in the south of Copenhagen: the plant, designed for 300,000 population equivalents, was already equipped with 1.600 efficient strip diffusers from Austria – with great success: “Our AEROSTRIPs were able to achieve a reduction in electricity consumption of approximately 40 percent compared to the previously installed surface aerators, which corresponds to approx. 2,000,000 kWh per year,” says Gerald Glaninger, sales manager at AQUACONSULT Anlagenbau GmbH. Due to the good experiences in Avedøre, the operating company BIOFOS A/S also relied on the Austrian technology for the two larger wastewater treatment plants, Lynetten and Damhusaen. It is now expected that this will result in further significant energy savings in the region.

All three plants are oxidation ditches where the waste water currently is, respectively was circulated and aerated by mammoth rotors. “ Strip diffusers are placed directly on the basin ground and exactly in this setting they are a highly efficient,” Mr. Glaninger explains. Studies confirmed huge energy savings from the widespread installation of strip diffusers in comparable wastewater treatment plant designs, which BIOFOS S/A’s retrofit project now aims to achieve in Copenhagen as well.

One billion Danish kroner for the first subproject.

The primary goal of the project, however, is to make room for more wastewater that can be treated in shorter time. This will involve speeding up the treatment process at BIOFOS’ three wastewater treatment plants – “without compromising on treatment quality,” as the company emphasized at the start of the project. The metropolitan area around Copenhagen would also continue to grow, meaning that more and more wastewater would have to be treated before it is discharged into the Danish Sund. The wastewater treatment plants need to keep up with the large volumes of water in the future, more than one billion Danish kroner (over 134 million euros) will be invested till 2027, the contracting parties announced. In fact, a total of five project phases are to ensure that the metropolitan region’s wastewater can be treated more comprehensively and efficiently by 2045.

The Outcome

The three wastewater treatment plants concerned, Avedøre, Damhusaen and Lynetten, will be equipped with around 11,000 AEROSTRIPS once the conversion expansion is complete. “This means that in future Aquaconsult’s strip diffusers will aerate the entire wastewater of the city of Copenhagen,” confirms Peter Dalgaard, project manager of the Danish company BioMizing, who is responsible for a significant section of the mega project in Copenhagen.