Coordinators:
UR REVERSAAL
Contact:
Sylvie GILLOT – sylvie.gillot(at)inrae.fr
Flora GIRARD – flora.girard(at)inrae.fr
Active period:
2026-2029
Financing:
National Research Agency (ANR), under recommendation by the European call Water4all
Partners:
- Aalto University, Finland
- Ghent University, Berlgium
- Gdansk Tech, Poland
- INSA Toulouse, France
Background:
The objective of the Red-SuN project is to foster the development and implementation of innovative and sustainable routes to remove and/or recover nitrogen from wastewater within the European revised urban wastewater treatment directive. The research vision of the Red-SuN project relies on the fact that compliance with the revised UWWTD will foster innovation in wastewater nutrient management.
In November 2024, the European council definitively adopted the text for a revised directive on urban wastewater treatment, which will impose large wastewater treatment plants to lower their nitrogen discharge levels in the coming years. This represents an unprecedent opportunity to develop and evaluate new innovative solutions for nitrogen management, and to help closing the N-cycle.
Objectives:
The Red-SuN project aims at proposing and evaluating new routes to treat and/or recover nitrogen from wastewater within this revised directive without compromising the carbon-footprint of the plants. An in-depth evaluation of the current practice in terms of nitrogen treatment in the four countries participating to the project (France, Finland, Poland and Belgium) and of the required optimization/retrofitting of the existing plants to meet the revised European directive forms the starting point of the project. A full evaluation of innovative technologies to recover nitrogen from wastewater will also be carried out, as well as the impact assessment of the current and future N-related unit processes in terms of energy and chemical consumption and GHG emissions. The different scenarios will be assessed on a plant-wide level through simulation of full-scale installations, in order to propose and validate a methodology to select the best nitrogen management solutions to be implemented. Throughout the project, a close collaboration will be maintained with various stakeholders (water utilities in particular) who will share their data, their experiences and their vision towards the implementation of the new directive in a circular economy context.
The Red-SuN project targets the improvement of recovery technologies for nitrogen circularity between wastewater treatment, agriculture and industrial resource management sectors. This allows wastewater treatment utilities and industries to meet EU standards while reducing costs and keeping the carbon footprint low, providing agriculture with a sustainable alternative to synthetic fertilizers and supporting industrial circular economy practices. The impact is expected to include reduced nitrogen pollution, operational savings, decreased fertilizer dependency, and contributions to EU goals in terms of circular economy, climate, environmental protection and public health.
Organisation :
The Red-SuN project studies large scale WWTPs (or rather WRRFs), from agglomerations of 10 000 PE to more than 150 000 PE, and over the period 2022 to 2024. The research vision of the Red-SuN project relies on the fact that compliance with the revised UWWTD will foster innovation in wastewater nutrient management.
The coordination of all partners is organised into seven work packages which are interrelated, and with WP0 for coordination (Sylvie Gillot and Flora Girard) and WP6 for exploitation and dissemination of the results.
| WP1 Role of nitrogen recovery in future compliance - INRAE REVERSAAL (Sophie Guillaume Ruty) | Define the current situation in terms of nitrogen treatment and recovery in France, Finland, Poland and the Flemish Region |
| WP2 Nitrogen recovery technologies: evaluation and optimisation - Gdańsk Tech | Evaluation and optimisation of existing and innovative nitrogen recovery technologies from wastewater and sludge, including assessment of recovered nitrogen products in a circular economy context. |
| WP3 Ensuring the net zero goal – carbon footprint inventory of existing and emerging technologies - Aalto University | In order to build a carbon footprint inventory calculation model, existing and emerging technologies identified in WP1 and 2 will be scrutinised. 1. inventory and measurement of N2O 2. model development to calculate the carbon footprint and started to collect data from other projects |
| WP4 Multidisciplinary activities including stakeholder interactions - INSA Toulouse | 1. Involve stakeholders in the criteria definition and weighting for multi-criteria evaluation. 2. Co-construct the scenarios before simulating and optimising. 3. Share and co-evaluate the nitrogen removal and recovery scenarios and their reproducibility. 4. Synthesise feed-backs from stakeholders for future decision-making tools/approaches. |
| WP5 Multi-criteria optimisation and assessment of integrated schemes - Ghent University | In order to assess and compare N removal and recovery routes at plant-wide level, 3 case-studies will be evaluated through modelling. A multicriteria method for optimisation is to be developed, including the KPIs that will be agreed on in other WPs. |
Consortium:
Five academic partners will be associated in the Red-SuN project (INRAE and INSA Toulouse, France, Aalto, Finland, UGent, Belgium and GdańskTech, Poland). In addition to the competence required to develop the methodology and the models, the consortium partners are carrying out collaborative work with public end-users (water utilities, regulatory bodies…) and private end-users (water treatment companies, software developers, farming and agro-industry, fertilizer’s companies…). In particular, the partners will benefit from long-term collaborations with local water utilities, four of them having confirmed their participation in the project: Lyon Metropole (France), Helsinki Region Environmental Services (Finland), Aquafin (Belgium) and Chamber of commerce: Water Utilities (Poland). They will contribute to the definition of the evaluation criteria, give feedback on the assessed process schemes and commit to the sustainable implementation of successful project outcomes.
Anticipated benefits:
By combining state-of-the-art current practices with innovative removal and recovery technologies, Red-SuN will develop and validate a methodology to select the best solutions to be drawn up, in order to upgrade or redesign existing facilities, with a particular focus on identifying when, how and to what extent nitrogen recovery is both economically and environmentally viable. Red-SuN’s main research focus will be on wastewater nitrogen removal and recovery. Nevertheless, phosphorus recovery options will also be considered during the assessments, as they may interact with nitrogen management. Micropollutant removal, also targeted in the revised UWWTD, will be considered insofar it affects the WWTP’s carbon footprint.
Developing this methodology requires to fill the data gaps in terms of performance of novel nitrogen recovery techniques, of quality of the recovered products and of carbon footprint for treatment and recovery processes.
The proposed method builds on the use of plant-wide modelling that requires the development and validation of specific models for nitrogen recovery processes. The methodology will be developed and illustrated using three case studies. The criteria to be included in the evaluation as well as the identification of the relevant case studies will be established in strong collaboration with key stakeholders, i.e., water authorities and utilities.
