InnovativaInnovative Bioretention Filters using Alternative Sorbent Materials and Resilient Plants for the Treatment of Urban Stormwater: From Pilot to Full-scale med alternativa sorbentmaterial och motståndskraftiga växter

Research Project, 2025 – 2027

Urban stormwater pollution is a major environmental issue, particularly in densely populated and heavily trafficked areas where impermeable surfaces limit natural infiltration. Runoff transports complex mixtures of pollutants into water bodies containing metals, nutrients, organic pollutants, microplastics, and tyre wear particles, threatening ecosystems and human health. Climate change complicates stormwater management, as droughts and heavy rainfall can exacerbate the spread of pollutants. This project aims to develop innovative bioretention filters consisting of alternative sorbent materials such as Sphagnum peat, pine bark, biochar from spruce, and bottom ash from waste-to-energy processes, in combination with resilient plant species for phytoremediation to improve stormwater treatment efficiency. The main goal is to create a design guide for implementing bioretention filters, helping municipalities and consultants to effectively treat polluted stormwater based on findings from the Gårda raingarden pilot. The study aims to identify the best designs and combinations of sorption materials, study the impact of atmospheric deposition of pollutants, as this is indicated as a significant source of pollution, assess the long-term performance of the filters, where microplastics and PFAS are also included, but also to provide recommendations for urban stormwater management. A multicriteria decision analysis will assess the sustainability and scalability of the filters.