Exploitation décentralisée des ressources issues des eaux usées

En Suisse comme ailleurs, économiser les ressources revêt une importance accrue. Comme c’est le cas depuis longtemps pour le recyclage des déchets, il est également possible de récupérer efficacement des ressources dans les eaux usées. L’Eawag travaille de manière interdisciplinaire sur des solutions durables servant à la fois les populations et l’environnement.

Cycle des ressources à l’échelle d’un bâtiment: les flux d’eaux usées sont séparés à la source, les ressources dégagées sont réutilisées (Infographie: Daniel Röttele / infografik.ch) Cliquer sur le graphique pour l'agrandir
Cycle des ressources à l’échelle d’un bâtiment: les flux d’eaux usées sont séparés à la source, les ressources dégagées sont réutilisées (Infographie: Daniel Röttele / infografik.ch)
Cliquer sur le graphique pour l'agrandir


La construction de canalisations et de stations d’épuration des eaux usées (STEP) pour un traitement centralisé a permis durant le siècle dernier de réaliser des progrès significatifs en matière d’hygiène et de santé humaine, mais aussi au regard de la protection de l’environnement en périphérie des villes et des villages. Pourtant, ce système consomme de grandes quantités d’eau et complique la récupération des matières recyclables contenues dans les eaux usées. Le changement climatique, la forte concentration de nutriments dans l’environnement, la croissance de la population ainsi que la perte massive de biodiversité nous contraignent à repenser le système existant. Si les périodes de canicule deviennent plus fréquentes et que les précipitations se décalent, de grandes quantités d’eau seront nécessaires dans les villes toujours plus peuplées. Les matières recyclables contenues dans les eaux usées telles que le phosphore et l’azote deviendront des substances problématiques si elles se déversent dans les cours d’eau naturels. Simultanément, le phosphore doit être extrait et importé dans des conditions polluantes parce que l’agriculture s’en sert d’engrais.

Outre la protection de la santé humaine et des cours d’eau, l’utilisation efficiente des ressources issues des eaux usées est donc un objectif du traitement de celles-ci. Une approche en ce sens consiste à boucler aussi localement que possible les cycles de l’eau, des nutriments et de l’énergie. De nouvelles technologies reposant sur le concept de séparation à la source permettent un traitement décentralisé des eaux usées, sur place et dans un espace restreint.

Actualités

Actualités

Événements

20.01.​2026
Cours axés sur la pratique
Systèmes d'assainissement circulaires : technologies, opportunités et défis
9h00
Eawag Dübendorf

Contexte

Informations approfondies sur le sujet.
 

Selon l'approche choisie, les eaux usées peuvent être traitées dans des stations d'épuration centrales pour des communes entières ou de manière décentralisée dans des bâtiments ou des quartiers.
Traitement des eaux usées – centralisé, décentralisé, hybride
Les ressources peuvent être récupérées plus efficacement à partir des eaux usées si les différents flux d'eaux usées sont séparés dans les toilettes.
Ressources issues des eaux usées – séparation à la source

Actualité

Le Global Science Film Festival a nominé le court-métrage «Verhebets? Un apéritif axé sur les ressources» par les chercheurs juniors de l'Eawag dans la catégorie "Best Short Film 2023".

Verhebets? Un apéritif axé sur les ressources

L'obligation de raccordement est un argument de poids contre la mise en œuvre de systèmes sanitaires décentralisés et orientés vers les ressources. De plus, il n'existe aucune connaissance de mise en œuvre de telles installations en Suisse. Les jeunes chercheurs du programme Wings se sont demandé : "Est-ce vraiment le cas ?" Dans leur nouveau projet vidéo, ils dissipent les mythes autour des systèmes d'assainissement axés sur les ressources.

Transfert de connaissances

Comment mettre nos connaissances en pratique.

 
Water Hub

Développement d'une gestion décentralisée de l'eau et des eaux usées dans le bâtiment NEST de l'Eawag et de l'Empa.

 
Vuna

Ancienne spin-off de l'Eawag, spécialisée dans la récupération des nutriments contenus dans l'urine.

Publications pour l’application pratique

2022
Recyclage décentralisé des ressources issues des eaux usées
Eawag Newsletter Spécial
2022
Forschen mit Fäkalien
Comicreportage, Eawag
2022
Eaux noires
Factsheet [pdf, 597.4 KB]
2021
Eaux grises
Factsheet [pdf, 258.9 KB]
2019
Collecte sélective des urines (2019)
Factsheet [pdf, 353.9 KB]
2018
Resource Recovery from Waste
Book, International Water Management Institute
2013
Source Separation and Decentralization for Wastewater Management
Book, IWA Publishing

Expertes et experts

Séparation de l'urine

Prof. Dr. Kai Udert
  • séparation des eaux usées
  • technologies décentralisées
  • nutriments
  • séparation des urines
  • Récupération de ressources

Traitement des eaux grises

Prof. Dr. Eberhard Morgenroth
  • eaux usées
  • technologies décentralisées
  • nutriments
  • gestion des eaux urbaines
  • urbanisme
  • séparation des urines
Dr. Frederik Hammes
  • biofilms
  • Cytométrie en flux
  • légionelles
  • Mikrobiologie
  • senseurs
Dr. Tim Julian
  • microbes
  • assainissement

Traitement des eaux noires

Dr. Linda Strande
  • assainissement
  • changements climatiques
  • Récupération de ressources
  • systèmes décentralisées
  • écologie microbienne

Wings

Dr. Sabine Hoffmann
  • gestion durable de l'eau
  • participation des acteurs
  • interface entre la science et la politique
  • recherches transdisciplinaires

Projets de recherche

In Autarky entwickeln wir kleine Anlagen für die getrennte Behandlung von Urin, Abwasser und Fäkalien direkt in der Toilette.
Blue Diversion AUTARKY – Abwasserbehandlung ohne Netzanschluss
En récupérant les nutriments contenus dans les urines, nous développons un système sanitaire, qui produit des engrais
VUNA - Récupération de nutriments des urines
Partout dans le monde, les populations sont confrontées à des problèmes d'approvisionnement en eau. Les causes principales sont la demande…
Réutilisation des eaux grises à l’Eawag
Ist ein Raumfahrtforschungs- programm, das die Entwicklung eines bioregenerativen Lebenserhaltungssystems für langfristige…
Melissa «Micro Ecological Life Support System Alternative»
Wir untersuchen die Herausforderungen modularer Infrastrukturen für die Schweizer Wirtschaft und Gesellschaft am Beispiel der…
COMIX: Modulare Wasserinfrastrukturen
Ressourcenrückgewinnung, marktbasierte Ansätze und Geschäftsmodelle sind der Schlüssel zu nachhaltigem Management.
Rückgewinnung von Ressourcen
Le programme de recherche stratégique inter- et transdisciplinaire vise à développer des systèmes d'approvisionnement en eau et…
Wings

Publications académiques

In-building heat recovery mitigates adverse temperature effects on biological wastewater treatment: a network-scale analysis of thermal-hydraulics in sewers

Heat recovery from wastewater is a robust and straightforward strategy to reduce water-related energy consumption. Its implementation, though, requires a careful assessment of its impacts across the entire wastewater system as adverse effects on the water and resource recovery facility and competition among heat recovery strategies may arise. A model-based assessment of heat recovery from wastewater therefore implies extending the modeling spatial scope, with the aim of enabling thermal-hydraulic simulations from the household tap along its entire flow path down to the wastewater resource recovery facility. With this aim in mind, we propose a new modeling framework interfacing thermal-hydraulic simulations of (i) households, (ii) private lateral connections, and (iii) the main public sewer network. Applying this framework to analyze the fate of wastewater heat budgets in a Swiss catchment, we find that heat losses in lateral connections are large and cannot be overlooked in any thermal-hydraulic analysis, due to the high-temperature, low-flow wastewater characteristics maximizing heat losses to the environment. Further, we find that implementing shower drain heat recovery devices in 50% of the catchment's households lower the wastewater temperature at the recovery facility significantly less – only 0.3 K – than centralized in-sewer heat recovery, due to a significant thermal damping effect induced by lateral connections and secondary sewer lines. In-building technologies are thus less likely to adversely affect biological wastewater treatment processes. The proposed open-source modeling framework can be applied to any other catchment. We thereby hope to enable more efficient heat recovery strategies, maximizing energy harvesting while minimising impacts on biological wastewater treatment.
Hadengue, B.; Joshi, P.; Figueroa, A.; Larsen, T. A.; Blumensaat, F. (2021) In-building heat recovery mitigates adverse temperature effects on biological wastewater treatment: a network-scale analysis of thermal-hydraulics in sewers, Water Research, 204, 117552 (11 pp.), doi:10.1016/j.watres.2021.117552, Institutional Repository

The potential contribution of urine source separation to the SDG agenda - a review of the progress so far and future development options

Sanitation and wastewater management are highly relevant for reaching a number of interconnected sustainable development goals (SDGs), especially SDG 6, the provision of safe drinking water and adequate sanitation for all as well as protection of water resources against pollution, and SDG 14.1, reducing nutrient emissions to the marine environment. Recent evidence increasingly shows that conventional sewer-based wastewater management will not be able to reach these targets. Rather than further optimizing and diffusing this ageing infrastructure paradigm, radical innovations like urine source separation technologies could help to leapfrog towards faster achievement of the SDGs. The technology would simplify on-site sanitation and develop a closed-loop nutrient cycle, thereby allowing for exceptionally high nutrient removal from wastewater and direct reuse in agriculture from the first day of implementation. Radical innovations, however, need decades to materialize. Based on a review of relevant academic and grey literature, we show how the past three decades of development of urine source separation have brought breakthroughs in toilet design and treatment processes, enabling the technology's value chain to reach the brink of maturity. In a short outlook, we discuss how the technology may reach global diffusion over the next decade, with the main remaining challenges relating to the creation of mass-markets for urine-diverting toilets, automation and mass-production of treatment systems, and the legitimation of fertilizer produced from urine in the agricultural sector.
Larsen, T. A.; Gruendl, H.; Binz, C. (2021) The potential contribution of urine source separation to the SDG agenda - a review of the progress so far and future development options, Environmental Science: Water Research and Technology, 7(7), 1161-1176, doi:10.1039/D0EW01064B, Institutional Repository

State of the art of urine treatment technologies: a critical review.

Over the last 15 years, urine treatment technologies have developed from lab studies of a few pioneers to an interesting innovation, attracting attention from a growing number of process engineers. In this broad review, we present literature from more than a decade on biological, physical-chemical and electrochemical urine treatment processes. Like in the first review on urine treatment from 2006, we categorize the technologies according to the following objectives: stabilization, volume reduction, targeted N-recovery, targeted P-recovery, nutrient removal, sanitization, and handling of organic micropollutants. We add energy recovery as a new objective, because extensive work has been done on electrochemical energy harvesting, especially with bio-electrochemical systems. Our review reveals that biological processes are a good choice for urine stabilization. They have the advantage of little demand for chemicals and energy. Due to instabilities, however, they are not suited for bathroom applications and they cannot provide the desired volume reduction on their own. A number of physical-chemical treatment technologies are applicable at bathroom scale and can provide the necessary volume reduction, but only with a steady supply of chemicals and often with high demand for energy and maintenance. Electrochemical processes is a recent, but rapidly growing field, which could give rise to exciting technologies at bathroom scale, although energy production might only be interesting for niche applications. The review includes a qualitative assessment of all unit processes. A quantitative comparison of treatment performance was not the goal of the study and could anyway only be done for complete treatment trains. An important next step in urine technology research and development will be the combination of unit processes to set up and test robust treatment trains. We hope that the present review will help guide these efforts to accelerate the development towards a mature technology with pilot scale and eventually full-scale implementations.
Larsen, T. A.; Riechmann, M. E.; Udert, K. M. (2021) State of the art of urine treatment technologies: a critical review., Water Research X, 13, 100114 (20 pp.), doi:10.1016/j.wroa.2021.100114, Institutional Repository

Making waves: why water reuse frameworks need to co-evolve with emerging small-scale technologies

Novel technologies allow to reuse or recycle water for on-site applications such as toilet flushing, showering, or hand washing at the household- or building-scale. Many of these technologies have now reached technology readiness levels that require for verification and validation testing in the field. Results from such field tests of decentralized water reuse systems have been published over the past few years, and observed performance is often compared to quality targets from water reuse frameworks (WRFs). An inspection of ten recent journal publications reveals that targets from WRFs are often misinterpreted, and the emphasis of these publications is too often on demonstrating successful aspects of the technologies rather than critically evaluating the quality of the produced water. We hypothesize that some of these misinterpretations are due to ambiguous definition of scopes of WRFs (e.g., "unrestricted urban reuse") and unclear applicability for novel recycling systems that treat the water for applications that go beyond the reuse scopes defined in current WRFs. Additional challenges are linked to the verification of WRF quality targets in small-scale and decentralized systems under economic and organizational constraints. Current WRFs are not suitable for all possible reuse cases, and there is need for a critical discussion of quality targets and associated monitoring methods. As the scope of water reuse has expanded greatly over the past years, WRFs need to address new applications and advances in technology, including in monitoring capacities.
Reynaert, E.; Hess, A.; Morgenroth, E. (2021) Making waves: why water reuse frameworks need to co-evolve with emerging small-scale technologies, Water Research X, 11, 100094 (5 pp.), doi:10.1016/j.wroa.2021.100094, Institutional Repository

Emerging solutions to the water challenges of an urbanizing world

The top priorities for urban water sustainability include the provision of safe drinking water, wastewater handling for public health, and protection against flooding. However, rapidly aging infrastructure, population growth, and increasing urbanization call into question current urban water management strategies, especially in the fast-growing urban areas in Asia and Africa. We review innovative approaches in urban water management with the potential to provide locally adapted, resource-efficient alternative solutions. Promising examples include new concepts for stormwater drainage, increased water productivity, distributed or on-site treatment of wastewater, source separation of human waste, and institutional and organizational reforms. We conclude that there is an urgent need for major transdisciplinary efforts in research, policy, and practice to develop alternatives with implications for cities and aquatic ecosystems alike.
Larsen, T. A.; Hoffmann, S.; Lüthi, C.; Truffer, B.; Maurer, M. (2016) Emerging solutions to the water challenges of an urbanizing world, Science, 352(6288), 928-933, doi:10.1126/science.aad8641, Institutional Repository

A research agenda for the future of urban water management: exploring the potential of non-grid, small-grid, and hybrid solutions

Recent developments in high- and middle-income countries have exhibited a shift from conventional urban water systems to alternative solutions that are more diverse in source separation, decentralization, and modularization. These solutions include non-grid, small-grid, and hybrid systems to address such pressing global challenges as climate change, eutrophication, and rapid urbanization. They close loops, recover valuable resources, and adapt quickly to changing boundary conditions such as population size. Moving to such alternative solutions requires both technical and social innovations to co-evolve over time into integrated socio-technical urban water systems. Current implementations of alternative systems in high- and middle-income countries are promising, but they also underline the need for research questions to be addressed from technical, social, and transformative perspectives. Future research should apply a transdisciplinary research approach through socio-technical "lighthouse" projects that apply alternative urban water systems at scale. Such research should leverage experience from lighthouse projects in a range of socio-economic contexts, identify their potentials and limitations from an integrated perspective, and share their successes and failures across the urban water sector.
Hoffmann, S.; Feldmann, U.; Bach, P. M.; Binz, C.; Farrelly, M.; Frantzeskaki, N.; Hiessl, H.; Inauen, J.; Larsen, T. A.; Lienert, J.; Londong, J.; Lüthi, C.; Maurer, M.; Mitchell, C.; Morgenroth, E.; Nelson, K. L.; Scholten, L.; Truffer, B.; Udert, K. M. (2020) A research agenda for the future of urban water management: exploring the potential of non-grid, small-grid, and hybrid solutions, Environmental Science and Technology, 54(9), 5312-5322, doi:10.1021/acs.est.9b05222, Institutional Repository

Photo de couverture: Daniel Röttele/infografik.ch