A research and innovation project funded by the Re:Source strategic innovation programme is redefining the potential of water treatment plants, transforming them into resource hubs. The project, which began in August 2022, focuses on enhancing EasyMining’s Ash2Phos technology by introducing an add-on process that maximizes the recovery of valuable materials like phosphorus, iron coagulants, and silicate sand from sewage sludge ash.
Cleaner and Sustainable Alternatives for Key Materials
At the heart of the innovation lies the ability to recover over 85 percent of the iron present in sewage sludge ash, alongside the already impressive recovery of 90 percent of phosphorus in the main process. The recovered iron, processed into high-purity ferric chloride, meets drinking water quality standards and offers a sustainable alternative to traditional coagulants. Tests with industry collaborators Feralco and Sydvatten confirm the high purity of ferric chloride produced.
Cristian Tunsu, Laboratory Manager at EasyMining, emphasized the significance of this achievement:
“Our process demonstrates that it is possible to significantly increase the recovery of iron, improving circularity in the water treatment sector while reducing reliance on virgin materials.”
Environmental and Economic Benefits
The new process is also a win for the environment. A life cycle assessment conducted for the planned Ash2Phos plant in Helsingborg revealed that recycled ferric chloride has a carbon footprint of just 75 kg CO2 per tonne, compared to 140 kg CO2 per tonne for virgin magnetite-based ferric chloride.
In addition, the silicate sand left after iron extraction is now free from iron compounds, expanding its potential applications. The sand can be used as a substitute for cement in concrete, further reducing CO2 emissions and offering a valuable solution for the construction industry. EasyMining is pursuing a European Technical Assessment (ETA) to certify these recycled materials for broader use.
Innovations That Enhance Circularity
The technology represents a breakthrough for circular material use in the water treatment and construction sectors. By recovering iron as ferric chloride, phosphorus, and aluminum, and producing clean silicate sand as a co-product, the add-on process not only optimizes resource recovery but also provides solutions to pressing environmental challenges.
Collaboration and Future Potential
This initiative has also strengthened partnerships within the water treatment sector while opening up new business opportunities. The collaboration with Feralco and Sydvatten highlights the commercial viability and environmental benefits of the process.
“We are seeing great interest from sectors like water treatment and construction, where the ability to recover iron and replace cement with silicate sand could lead to considerable cost savings and reduced CO2 emissions,” adds Tunsu.
Towards a Circular Future
By enabling water treatment plants to function as resource plants, this project underscores the potential of waste to become a valuable resource. The innovative approach not only supports sustainability goals but also addresses economic and environmental challenges. Funded by the Swedish Energy Agency, Vinnova, and Formas, this project exemplifies the power of strategic innovation in driving progress toward a circular economy.
