Wastewater

Wastewater: waste, recyclable material and early warning system

Efficient wastewater discharge and treatment infrastructures are essential for public health and water quality. Eawag’s research contributes to optimising these systems. However, wastewater also contains resources that can be recovered. In addition, it is a reflection of our health and consumption patterns, in which infectious diseases, for example, can be monitored. Eawag is also conducting research into this area.

Meeting new challenges

In Switzerland, around 50,000 km of public sewers and about 800 communal wastewater treatments plants (WWTPs) ensure that wastewater and rainwater are drained and treated before they enter bodies of water again. However, the system is constantly confronted with new challenges, such as micropollutants from household chemicals or pharmaceuticals, microplastics or antibiotic resistance. Increased heavy rainfall can also overload the sewage systems. With its research, Eawag is helping to continuously optimise the wastewater system so that the high quality of Swiss bodies of water can be maintained. It also operates its own experimental sewage treatment plant for this purpose.

Over-fertilisation and climate protection

On average, wastewater treatment plants in Switzerland have to date only removed about half of the nitrogen contained in wastewater. The rest ends up in the bodies of water and contributes to over-fertilisation. However, some of the nitrogen also escapes into the air in the form of nitrous oxide. Nitrous oxide is one of the most significant greenhouse gases and also destroys the ozone layer. Eawag is therefore developing processes to quantify nitrogen leaks and make nitrogen removal more efficient and targeted.

Closing loops with decentralised systems

In the existing Swiss sewage system, urine, faeces and toilet paper are mixed and flushed away. This not only consumes a lot of water, but also makes it difficult to recover the valuable substances contained in the wastewater. Eawag is therefore researching new approaches in which the different wastewater streams are drained and treated separately. In this way, nutrients and energy can be recovered, and water can be saved and reused. Similar approaches can also be used in regions that are not connected to the water and sanitation network or where water is scarce. Eawag is developing technologies to enable the provision of good sanitation in such regions as well.

Monitoring infectious diseases and drug use

Wastewater is full of information about our health and consumption patterns. Thanks to these traces, it can be used, among other things, as an early warning system for the spread of infectious diseases. Eawag is working to extend the method it developed with partners for monitoring SARS-CoV-2 to other pathogens. Another Eawag project is concerned with the monitoring of addictive substances such as alcohol, drugs, medicines and tobacco in wastewater.

Research projects

Network

We work together with a wide variety of partners.

The FOEN Water Division is responsible for the protection of surface water, groundwater and drinking water.

Federal Office for the Environment (FOEN)

AWEL is a representative of all cantonal environmental or water protection agencies with which Eawag cooperates.

Office of Waste, Water, Energy and Air of the Canton of Zurich (AWEL)

The VSA is the Swiss professional organisation in the field of integral water management.

Swiss Water Association (VSA)

The FOPH is responsible for the protection of public health, health policy and the health system.

Federal Office of Public Health (FOPH)

The CoUDLab brings together European research and innovation activities and testing facilities on urban drainage systems.

CoUDLabs

Experts

Dr. Christian Binz
  • decentralized systems
  • innovation
  • global change
  • sustainable transitions
  • urban water management
Marc Böhler
  • wastewater treatment
  • activated carbon
  • micropollutants
  • ozonation
  • trace substance elimination
Dr. Helmut Bürgmann
  • antibiotic resistance
  • bacterioplankton
  • Microbiology
  • nutrients
  • surface water
Dr. Nicolas Derlon
  • wastewater
  • wastewater treatment
  • wastewater treatment plant
Prof. Dr. Juliane Hollender
  • Computational methods
  • biological degradation
  • bioaccumulation
  • groundwater
  • mass spectrometry
Dr. Adriano Joss
  • wastewater
  • micropollutants
  • ozonation
Dr. Joao Paulo Leitao
  • GIS
  • urban planning
  • modeling
  • Risk assessment
  • urban water management
PD Dr. Judit Lienert
  • decision analysis
  • public acceptability
  • sustainable water management
  • stakeholder participation
  • transdisciplinary research
Prof. Dr. Max Maurer
  • wastewater
  • decentralized technologies
  • sustainable water management
  • urban sanitation
  • urban water management
  • urine separation
Dr. Christa McArdell
  • activated carbon
  • wastewater treatment
  • mass fluxes
  • micropollutants
  • ozonation
Prof. Dr. Eberhard Morgenroth
  • wastewater
  • decentralized technologies
  • nutrients
  • urban water management
  • urban planning
  • urine separation
Dr. Lena Mutzner
  • modeling
  • water quality
  • micropollutants
  • monitoring
  • sustainable water management
Dr. Christoph Ort
  • wastewater
  • wastewater-based epidemiology
  • micropollutants
  • modeling
  • monitoring
Dr. Jörg Rieckermann
  • wastewater
  • modeling
  • urban water management
  • transdisciplinary research
Prof. Dr. Kai Udert
  • wastewater separation
  • decentralized technologies
  • nutrients
  • urine separation
  • resource recovery

Scientific publications

Pechaud, Y.; Derlon, N.; Queinnec, I.; Bessiere, Y.; Paul, E. (2024) Modelling biofilm development: the importance of considering the link between EPS distribution, detachment mechanisms and physical properties, Water Research, 250, 120985 (16 pp.), doi:10.1016/j.watres.2023.120985, Institutional Repository
Karakurt-Fischer, S.; Johnson, D. R.; Fenner, K.; Hafner, J. (2023) Making waves: Enhancing pollutant biodegradation via rational engineering of microbial consortia, Water Research, 247, 120756 (7 pp.), doi:10.1016/j.watres.2023.120756, Institutional Repository
Kizgin, A.; Schmidt, D.; Joss, A.; Hollender, J.; Morgenroth, E.; Kienle, C.; Langer, M. (2023) Application of biological early warning systems in wastewater treatment plants: Introducing a promising approach to monitor changing wastewater composition, Journal of Environmental Management, 347, 119001 (12 pp.), doi:10.1016/j.jenvman.2023.119001, Institutional Repository

Cover picture: Eawag researchers collect wastewater samples at the Werdhölzli wastewater treatment plant in Zurich, which they later test for SARS-CoV2 in the laboratory
(Photo: Eawag, Esther Michel).