FosfoCirk, a circular water regeneration & phosphorus-to-farm recovery project, will test various filters made from waste materials to define which has the best water-purifying and uptake of phosphorus. Ultimately, the goal will be to define the cost-effectiveness in a commercial application capturing and returning the phosphorus to the soil.
Phosphorus is essential for growing food, but when it runs off in excess from farmland it becomes a serious environmental problem. In Sweden, phosphorus runoff from agriculture is one of the main causes of eutrophication, clogged polluted rivers and lakes and contributes to algal blooms and oxygen depletion in the sea. At the same time, phosphorus is a finite resource that Sweden largely imports, making agriculture vulnerable to rising prices and possible supply disruptions.
The FosfoCirk project aims to address both challenges.
The project installs simple filtration systems in agricultural drainage water, and along the waterway where nutrients are most likely to be lost. As water passes through the filters, phosphorus is trapped instead of flowing into nearby waterways. The project will test various filters made from recycled waste materials, giving new value to resources that would otherwise go to waste.
Once the filters are saturated, the captured phosphorus can be returned to farmland as fertilizer or reused or value-added through further processing. This keeps nutrients in the local food system and reduces the need for imported mineral fertilizers. By stopping pollution at its source, FosfoCirk helps protect water quality while supporting more resilient and self-sufficient farming.
The project will demonstrate how environmental protection and resource efficiency can go hand in hand. FosfoCirk hopes to show that it is possible to reduce nutrient pollution, strengthen local agriculture, and move towards a more circular economy at the same time. If successful, the approach can be scaled and replicated across Sweden and beyond—contributing to cleaner water, healthier ecosystems, and a more sustainable future for food production.
Many thanks for the contributions from Svensk Postkodlotteriet – “Samhällsentreprenörer för en bättre värld” project
and the collaboration and assistance of Södertälje kommun Miljökontoret & Trosaåns Vattenvårdsförbund
