A research project in Boden will investigate whether residual oxygen from hydrogen production can be used to combat eutrophication in Svartbyträsket. A method that has been too expensive to test for a long time – but which may now become a reality.
Eutrophic lakes are a familiar problem in Boden. Svartbyträsket, one of the municipality’s most centrally located lakes, has suffered from a lack of oxygen, algae blooms and poor water quality for decades. Despite years of work – from siphon solutions to phosphorus ponds and reduction fishing – the basic problems remain.
Now a new track is being tested. Researcher Lina Hällström at Luleå University of Technology (LTU) has been given the opportunity to investigate whether excess oxygen from hydrogen production could be used to bind phosphorus and thus reduce algal blooms in the lake. The theory is that the oxygen can be used to create rust in the water – iron oxide – which in turn binds the nutrients and causes them to sink to the bottom.
“This is something I have been thinking about for over ten years. The theory is known, but there has never been a large-scale source of oxygen that has made it worthwhile to go ahead and look at the conditions. The step from test environment has been too big. When Stegra starts up, the conditions change – that’s why I want to test whether it works in practice too,” says Lina Hällström.
Small-scale testing
The project is still at the feasibility stage. The next step is to carry out a limited pilot experiment in the lake itself, where a module will be placed in the water to test the technology by simulating real-life conditions. The research team wants to find out which technology best preserves oxygen in the water – everything from nanobubbles to liquid gas is being discussed. The experiment will not use oxygen from Stegra – the focus is on testing the method itself, independent of future oxygen sources.
“The most important thing is that we get the oxygen to stay around long enough to react with the iron in the lake and form rust. If it works, we hope to show that phosphorus is reduced and the water becomes clearer.”
The project is fully research funded, including through LTU’s Jubilee Fund, the Baltic Fund and the Richertska Foundation and has a total budget of SEK 2 800 000. It is planned to last for two and a half years.
Municipality hopes for new piece of the puzzle
The municipality of Boden, which has been working for many years to improve the status of lakes, is one of the partners in the project. Environmental strategist Emilia Björkemyr says it is important to continue exploring new solutions – especially those that make use of resources that would otherwise be wasted.
“We see this as a potential piece of the puzzle in the long-term work with Lake Constance. It is one of several tracks we are looking at, and it is exciting to be able to link industrial development with nature conservation,” she says.
Emilia Björkemyr, Environmental Strategist, Municipality of Boden.
Local ownership and broad benefits
If the pilot trial is successful, the method could potentially be used in Svartbyträsket and also scaled up and used in more eutrophic lakes in Boden.
“As Stegra is expected to have a large surplus of oxygen, the amount needed will definitely be there, then it remains for us to find out if it is technically possible.
For Lina Hällström, who grew up in Boden, it is particularly meaningful to test her idea at home. And if the project succeeds, the benefits could be greater than just a healthier lake.
“Svartbyträsket is almost in the middle of town. “Imagine if we could get a swimming and fishing lake back in central Boden, that would be fantastic,” she says.
Facts: Lake Constance – long-term environmental work
Work to improve the water quality of Lake Constance has been ongoing for over 60 years. The Lake Constance Improvement Group includes Buddbyträsket, Bodträsket, Svartbyträsket, Lillavan, Bodån and Vittjärvsträsket. The problems began after water regulation in the Lule River and increased discharges of storm and waste water.
Previous measures include:
– 1968: First program of measures for purification, regulation and river water replenishment
– 1988: Heavy algal bloom and start-up of the Bodensee group
– 1993: Pumping of fresh river water to Svartbyträsket
– 2017-2023: Phosphorus ponds, floating wetlands and stormwater facilities
– 2018-2025: Annual reduction fisheries
