Since the inception of the WalNUT project, significant progress has been made at several stages, mainly in mapping nutrient recovery (NR) from wastewater (WW), testing recovery technologies and participating in pilot activities to validate these solutions. Initially, a comprehensive analysis was carried out to understand nutrient flows in the main European regions, creating a detailed picture of the potential for nitrogen (N) and phosphorus (P) recovery from WW effluents. This mapping effort provided essential baseline data to assess how WW effluents could compensate for inorganic fertilisers, promoting circular nutrient ecosystems and supporting regional nutrient balance. In addition, a meeting point has been developed between all the main actors in the management and treatment of WW and the production of bio-based fertilisers (BBF), thanks to the implementation of the WalNUT Nutrient Platform (WNP).
In the first project period, 15 WW N and P recovery technologies were identified, tested in laboratory settings and selected for further trials based on key performance indicators, including recovery potential and BBF productivity. Using the WalLAB decision-making tool, the most effective technologies were selected, leading to the design and installation of five pilot plants at municipal, industrial and desalination facilities. . These pilot plants are since then validating the selected technologies under relevant conditions, providing insights into the operational efficiencies and potential environmental impacts of the solutions.
Furthermore, performance tests of the BBFs are being carried out under controlled conditions, and the evaluation of their behaviour in field tests has been initiated.
On the other hand, the development of business models and market exploitation strategies have been carried out, aligned with the project's impact objectives, with a focus on creating viable commercial pathways for BBF production technologies. This includes identifying key stakeholders and building frameworks to support the sustainable scale-up of sustainable technologies, thus enabling the integration of nutrient recovery solutions within a circular bioeconomy.
Finally, Substantial progress has also been made in policy participation and dissemination. Moreover, work has started on the drafting of a white paper to guide legal and policy aspects. public awareness has been strengthened through the project's online platforms, press releases and specific events, as well as clustering activities with sister projects. These activities, managed by the consortium, aim to bridge knowledge gaps, raise awareness of the benefits of bio-based biotechnologies and foster collaboration between industry stakeholders, policy makers and the public.
