The EU-funded EuPolis project is developing a methodology for enhancing the health and well-being of citizens by creating urban ecosystems that harmonize the urban built environment with the natural environment through integrated nature-based solutions (NBS).

The Urban Ecosystem

Nature-based solutions in Gladsaxe offer multiple benefits to the local urban environment. By managing the natural water cycle through attractive blue-green urban solutions, they create biodiverse ecosystems, improve stormwater treatment and capture, and promote human health through interaction with nature.

Human health and the natural water cycle are enhanced by healthy urban waters in Denmark at the Gladsaxe housing development.

Water in the Urban Environment           

Water serves two primary functions within urban blue/green ecosystems. First, through the natural water cycle, it supports ecosystems and biodiversity by providing habitat for diverse plant and animal species and by supporting vegetation growth. The second is where water bodies help to regulate and mitigate impacts of excessive stormwater runoff and periods of drought and water scarcity by reducing the impacts of flooding, enhancing hydrologic infiltration leading to natural groundwater recharge, and also by acting as a natural buffer or retention pond for water storage.

The Need for Healthy Surface Waters

Urban surface waters are more susceptible to diffused source pollution since they are located in urban environments.  Good water quality must be maintained to prevent algal blooms, to maintain a healthy aquatic habitat, and to ensure that the stored water will be safe and healthy when cycled back into the natural water cycle or when used later for activities such as irrigation.

Bioengineering the Natural Environment

Biopolus Metabolic Network Reactor technology (MNR) utilizes a specially engineered ecosystem consisting of 2,000 to 3,000 species, including plants, microbes, and other higher-level organisms for high-level nature-based water treatment. The MNR system can be used to treat various water types, including wastewater and urban surface waters to a desired level of water quality.

The MNR system works by using natural and synthetic plant roots to provide optimal surface area for attached biofilm microbial growth, which, along with an aeration system, creates an engineered ecosystem with a healthy and diverse microbial community that can break down contaminants in water.

MNR Reactor Array
For wastewater treatment, the process takes place in a series of MNR reactors. As the water flows from one reactor to the next, it is continuously cleaned, as the various species in each tank break down the different contaminants.

An Attractive Solution for Surface Water Treatment

The MNR floating island at Gladsaxe and the pond itself creates a complex nature-based ecologically engineering environment. The MNR island works by creating a habitat for beneficial organisms on natural and artificial root surfaces (with a thriving biofilm microbial community), to treat and inoculate the pond water, maintaining good water quality and healthy ecology.

MNR Floating Island
For surface water treatment, the MNR technology has been adapted to swim above the waterbody. A man-made floating island contains plant racks that house specially selected native aquatic plants whose roots are submerged into the water. Below the plant racks are MNR artificial carriers that act as artificial root surfaces, which along with the plant roots create a habitat that is ideal for beneficial organisms. The MNR floating island is supplemented with an aeration/ circulation system, which helps maintain oxygen rich water in the waterbody.

The following illustration shows how the natural environment is enhanced through engineered ecosystem design, whereby mechanisms are installed for automated pond water aeration, using a micro-nano bubble generator, and water circulation via a system of pumps and a programed monitoring and control system.

The following rendering illustrates the attractive nature of the MNR floating island solution when it is used to treat and maintain the water in a small catch basin pond of an apartment complex.

Testing and Installation

The MNR floating island system will be installed at the Gladsaxe site during the first week of April 2025. Installation work will include the installation of the MNR floating island, the installation of the pond circulation and aeration equipment, planting and landscaping in and around the pond, and the integration of the monitoring equipment and the control logic with other onsite systems.

The MNR floating island was tested in Hungary, with preliminary plants, in a small lake in the town of Baja for approximately 6 months. The following image is the MNR floating island taken in the fall of 2024 on Lake Baja. 

Global Roll Out

The Gladsaxe complex stormwater management solution, which includes the MNR floating island, the evaporation system by BySpectrum, and the Biowater climapond by Amphi, provides an excellent nature-based solution for surface water management. The integrated system provides solutions for stormwater infiltration, stormwater retention and treatment, flood prevention, climate change adaptation, ecosystem restoration, increased biodiversity, and human health benefits through leisure areas and interaction with nature. The partners working on the Gladsaxe solutions are committed to the project and will continue to monitor and analyze the solutions after the completion of EuPolis. The ultimate goal is to exploit the results and to introduce the solution throughout Europe and the world, promoting local and sustainable decentralized circular urban water management.