This project has targeted utilisation of infrastructure for organic waste treatment in Sweden, in particular sewage sludge, to achieve increased production of high-value materials and energy carriers, reduced use of primary resources, and improved economic performance. We have investigated the sewage sludge management system as a socio-technical system facing a change, with integral connections to the energy and waste systems.

In conclusion, there is no silver bullet for the future of sewage sludge management. Indeed, it would have to be a full clip of silver bullets, as we found that a mishmash of different barriers –technical, economic, legal, and related to public perception – creates uncertainty that hinders progress regarding both sustainable long-term strategies and technological advancement. The Swedish sewage sludge management is largely fragmented, highlighting the need to shift directionto a more holistic approach. This can help actors address common issues rather than focussing solely on activity-specific problems. Introducing new legislation could be a key step, as the current specific legislation on sewage sludge has a seemingly insignificant role for today’s sludge management, compared to other legislation and the voluntary certification.

We have formulated six overall research highlights, to outline both published results and meta-conclusions based on combined insights. Each highlight is described separately in this report.