Small, porous beads made of clay are spread out all over a quiet laboratory in a small Norwegian town called Lillestrøm. The size of the beads varies and they can be as small as a piece of sand. Yet, they are said to be the possible answer to the current hot topic in water management: how to remove pollutants and other impurities from storm water before letting it back into nature?
The small beads are made of material called Leca, Light Expanded Clay Aggregate, and it can be used as filters that collect the pollutant as the water falls through them.
– Everyone is looking for a simple, robust solution to purify storm water and Leca beads coould be it, says Senior Project Manager Oddvar Hyrve from Saint-Gobain Building Materials, Leca.
Now the focus is on water quality
Climate change has increased, for example, flooding and heavy rainfall. Stormwater overflows grow rapidly in the urban areas, including the Nordic capital cities. The volume is a big issue, but according to Hyrve and his colleagues in Saint-Gobain Leca's research team, the focus has recently moved from handling the masses of water to how to also improve the quality of the water.
– We cannot just collect the stormwater and dump it in the rivers. We also need to do some cleaning. The change from the volume to the quality has happened during the last two years," Hyrve says.
His colleague, Project Manager Jaran Raymond Wood nods by his side.
– All governments have started to put legislation in place that regulates the quality of the water that is running out of the streets, tunnels and other infrastructure. There is a need for a solution and that is something we want to develop, he says.
Long-lasting and low-maintenance solution
The research team is soon finished with the material testing in the laboratories and they will focus more and more on the design of the filter beds. Leca beads can be applied as filtering layers in the ground for example by the highways or parking lots. When the water sinks through them, they collect the impurities and pollutants. And when designed in a proper way clean them.
– It is actually just a pure biological process, Hyrve summarises.
Saint-Gobain Leca has several decades experience of Leca material used as a media for water purification. Hyrve himself has worked for them for over 30 years. Products are sold all over the world, in cold climates as well as in warmer ones.
– We can see how transferable Leca material is. It is long-lasting and highly resistant against clogging. Using Leca beads for water filtering is a very interesting idea. It is a new approach to an old invention, Wood says.
He is looking forward to demonstrating the abilities in the pilots during 2017. Before that, there are still questions that need to be answered.
– If there's a really heavy rain, we need some kind of a system to avoid everything being flushed toward the filter and it gets overloaded, Hyrve says.
Only a few minutes could make a difference.
– If you can delay the peak when the heavy rain falls, you can actually purify the water instead of the water just floating through, Laboratory Engineer Tone Storbråten shares.
– We have to design filters so that they stand time. We also need to know what kind of maintenance is needed and what can we do with the filter materials afterwards, Hyrve lists.
Nordic knowledge benefits all businesses
These questions are central to the Norwegian KLIMA 2050 research project and its Nordic sister project STORMFILTER. The latter is led by VTT, and in cooperation with such industrial partners as Saint-Gobain Leca, it aims to generate clean technologies that can enhance stormwater management by retaining runoff water and improving water quality through pollutant filtering in the soil.
– When we participate in a project, we want to take an active role. We want to make sure we have enough resources for it, so we can also have an effect on the project, Hyrve shares.
To work with external partners was a strategic decision and it helps Saint-Gobain Leca to gain more knowledge and get more resources.
– We cannot do everything internally; we need partners from other organisations and countries. We also think it is important for our businesses to have competence centres in the Nordic countries, he states.
Networking across borders
Saint-Gobain Leca as a company designs, manufactures and sells mineral-based building materials, which makes buildings and infrastructure more environmentally friendly and durable. Their main research hub is in Norway.
– We use the same method of testing and analysis in all of our facilities around Europe, but we have centralised the core competence here. In this laboratory, we determine the guidelines, how to make declarations and carry out product improvements, Hyrve says.
He would also like to encourage other companies and organisations working with water management to share information and help create researcher networks across borders. The interest in finding pollutants trapping materials is worldwide, and sharing knowledge would be beneficial to all.
– I could say that what VTT has done in Finland could be copy-pasted into Norway and other countries, Hyrve says.
New topic for all
VTT's STORMFILTER research project aims to create knowhow to provide clean technologies that can help, for example, to improve water quality and compliment strategies for green urban living.
The two-year project started in 2015 and is a cooperation between Aalto University and the University of Helsinki alongside 17 Finnish and some international partners, like Saint-Gobain Leca.
– There's similar activities in both countries, and as this is a new topic for all of us, we have decided to cooperate and see if we are able to utilise the research and the results, Senior Project Manager Oddvar Hyrve says.
VTT and Saint-Gobain Leca have also done projects together earlier. Their previous cooperation was CLASS: Climate Adaptive Surfaces four years ago.
Both projects are funded by Tekes.
- Saint-Gobain Leca and VTT have a long history of cooperation.
- Saint-Gobain Leca designs, manufactures and distributes Light Expanded Clay Aggregate, Leca, materials and solutions.
- Their competence centre and main laboratory has been in the same place in Lillestrøm since the 1970s.
- Saint-Gobain Leca is actively participating in different research projects that aim to mitigate climate change and related issues.
- They currently participate in Norwegian KLIMA 2050 – Risk reduction through climate adaptation of buildings and infrastructure, which aims to reduce the societal risks associated with climate change and enhanced precipitation and flood water exposure within the built environment.
- STORMFILTER is its sister project led by VTT.