Department Environmental Chemistry

The VSA Water Quality Platform and Eawag have analysed the effects to date of the measures taken under the "Action Plan for Risk Reduction and Sustainable Use of Pesticides" on water quality. The number of limit value exceedances has decreased significantly since 2019. Nevertheless, many kilometres of rivers and streams are still contaminated. Pyrethroids pose a particularly high risk to watercourses.

A survey of 99 small Swiss streams reveals that the majority of the studied streams have significant deficits in their ecological condition and can only fulfil their function as a habitat for animals to a limited extent. Insect larvae and other small animals that react sensitively to pesticides are missing in over 70% of the streams examined. Statistical analyses indicate that these aquatic organisms are particularly impacted when the structure and morphology of the stream bed has been altered or if the proportion of agricultural land in the catchment area is high.

Eawag and the Ecotox Centre welcome a total revision of the Plant Protection Products Ordinance (PPPO). However, the two institutes are calling for improvements on important points, such as the adoption of EU authorisations or the precautionary principle. The ordinance must ensure that other regulations such as the Water Protection or the Environmental Protection Act are not undermined.

The development of Swiss wastewater treatment is ongoing. Eawag studies now show that there is also potential for improvement in the case of emissions from chemical and pharmaceutical plants – both at wastewater treatment plants and within industrial facilities.

To coincide with the World Economic Forum (WEF) in Davos, the ETH Domain invited 50 dignitaries from the political, research and business spheres, to Davos and presented highlights from its current research. Eawag demonstrated how its work has successfully paved the way for advanced wastewater treatment.

A team of seven current and former Eawag researchers will receive the Swiss Chemical Society’s Sandmeyer Prize in 2024 for the development of advanced wastewater treatment for the degradation of micropollutants using ozone. And the most amazing thing is: Just about 15 years have passed between basic research and large-scale technical implementation. This incredible timetable was only possible thanks to the wealth of knowledge already available at Eawag and the fact that interdisciplinary collaboration is a matter of course at the Swiss aquatic research institute.

On ETH Day, Charlotte Bopp was honoured with the Otto Jaag Water Protection Prize for her dissertation. In January, she will also receive the ETH Medal for her work.

The mandate for the “Water Quality” and “Process Engineering Micropollutants” platforms supported by Eawag, FOEN and VSA has been extended by an additional four years.

The guidelines of the WHO list only four substances produced by cyanobacteria. This is a small fraction of all the metabolites that can have ecotoxicological effects.

While the use of pesticides in industrial countries is being questioned more and more critically, less is known about their consequences on human health and the environment in tropical countries. The interdisciplinary project “Pestrop” is now changing this and also shows where the necessary measures need to be taken.

The aquatic research institute Eawag has published its latest annual report and looks back on the year 2022. Water is at the heart of the most important environmental issues.

Eawag researcher Johannes Raths has won a prize for his study of increased pollutant absorption with rising water temperatures.

Martin Ackermann has been head of Eawag since January. At his request, the ETH Board has now appointed three new members to the Directorate. Lenny Winkel, Florian Altermatt and Christian Stamm, who now becomes deputy director.

Environmental chemist Kathrin Fenner was promoted by the University of Zurich to full professor ad personam of environmental chemistry. She explains what motivates her to teach.

Work is currently underway in Montreal at the UN Biodiversity Conference (COP 15) to negotiate a framework agreement to preserve biodiversity. In addition to pesticides, nutrients and plastic waste, certain other chemicals ought to be restricted in their production and use, or replaced by less problematic substances, according to a recommendation by a group of scientists, including an environmental toxicologist from Eawag.

How can the use of scientific knowledge be promoted in policy and practice to make plant protection more sustainable?

Together with the Canton of St. Gallen, Eawag has been investigating the impact of the expansion of the wastewater treatment plant at Flawil to include a stage for the removal of micropollutants on water quality in the River Glatt. Initial results now show a very positive picture.

Eawag researchers Wenzel Gruber and Urs Schönenberger have won this year's Otto Jaag Water Protection Prize for their dissertations. Reducing emissions of the climate-damaging nitrous oxide from wastewater treatment plants and reducing the leaching of pesticides from drainage systems are the topics.

Even though industrial wastewater is treated at state-of-the art plants, the sheer variety of synthetic organic compounds from the chemical and pharmaceutical industry which end up in surface waters are seriously underestimated. This is shown by a new study carried out by Eawag and ETH Zurich.

It is no secret that climate change has a serious impact on the quality and ecology of aquatic environments. Researchers at Eawag have revealed that human responses to climate change are just as impactful on our water systems – for example, in the areas of agriculture and hydropower.

Ozonation is an established treatment process to remove micropollutants from wastewater. However, since unstable toxic reaction products can be formed in the process, biological post-treatment is necessary. Results from the Ecotox Centre and Eawag show how well different post-treatment methods reduce ecotoxicological effects. The combination of ozonation and activated carbon proved to be the most effective.

With the support of Eawag, experts from the VSA platform "Process Engineering for Micropollutants" investigated the inputs of substances from industry and commerce into waterbodies. The nationwide analysis shows that treated wastewater from businesses also contains micropollutants that enter waterbodies.

In a documentary on pesticides in Swiss surface waters, the SRF programme 10vor10 reported on new research results from the Environmental Chemistry Department.

A river with chemically polluted sediments at its bottom is missing a crucial habitat. However, until now there has been no uniform method for monitoring the quality of sediments. On behalf of the Federal Office for the Environment, experts from the Ecotox Centre and Eawag have now developed a proposal for this.

All living organisms that respire have to get rid of electrons. In oxygen-free environments, microorganisms deploy special molecules which act as extracellular electron shuttles to transfer the electrons from cells to minerals. A group of researchers has now discovered what determines the electron transfer efficiency of these “taxi” cars: the energy differences of the transported electrons.

With around 200 pictures and texts, the new Water Timeline takes you through 200 years of the eventful history of Swiss water protection. It aims to show how shifts towards more sustainable management of natural resources can be shaped. 

Researchers Christoph Vorburger and Florian Altermatt talk about the importance and state of aquatic biodiversity in Switzerland and Eawag’s commitment to conserving natural biodiversity.

Researchers Juliane Hollender, Bernhard Truffer and Urs von Gunten from the aquatic research institute Eawag are among the "highly cited researchers 2021".

The environmental chemist Barbara F. Günthardt and the two environmental engineers Matthew Moy de Vitry and Marius Neamtu are awarded the ETH Medal for their doctoral theses. Plant toxins, urban flooding and complicated flows were the topics. Congratulations!

Open Science is an important development in science - open access to the results of research. Eawag supports these and makes a growing part of its research data, including descriptions, images and even software, available publicly and free of charge on the Eawag platform ERIC or, in special cases, on discipline-specific, international databases. ERIC complements the long-standing platform DORA for scientific publications.

With the latest analytical methods, potentially toxic substances can be detected even at very low concentrations. However, the aim of research is not merely to document such contamination but also to understand how it occurs in streams and groundwater, and to propose mitigation measures.

The motto of today’s World Water Day is “Valuing water – What means water to you?”. With this motto, the United Nations wants to raise awareness of the vital importance of water and call on people to think about the value of water. In an interview, Eawag Director Janet Hering explains the importance of water for the aquatic research institute Eawag and also her personally.

New pharmaceuticals are being launched on the market all the time. It is of course their effectiveness in people’s health that is of central importance here, but at some point, their active ingredients or traces of them wind up in the environment, where they can have negative consequences. A large-scale EU project in which Eawag is also participating is now trying to help ensure that possible environmental impacts of pharmaceuticals are recognised by the pharmaceutical industry and the relevant approval bodies in the early stages of a drug’s development.

The mobile and automated MS2field mass spectrometer allows measurements to be taken of harmful substances in surface waters with high temporal resolution. The initial measurements using the device are revealing the extent to which peak concentrations of pesticides, for example, have been underestimated by traditional methods.

Researchers Juliane Hollender, Ole Seehausen, Bernhard Truffer and Urs von Gunten from the aquatic research institute Eawag are among the "highly cited researchers 2020".

In agricultural areas, large volumes of water from fields, roads and paths drain directly into streams via manholes and other forms of artificial drainage. These shortcuts also transport pesticides into surface waters – and, according to a new study, in significantly larger quantities than was previously assumed.

Researchers from Agroscope, Eawag, University of Bern and ETH have developed a method for the comprehensive detection of organic pollutant residues in soils and sediments. Initial results show that, in addition to known substances, there are also a number of substances detected for the first time.

Blue-green algae are very common both in the water and on land. Sporadically, they occur in lakes on the surface in such large numbers that one speaks of a bloom. Because there are species that can produce toxic substances, many questions arise.

In addition to ozonation, filters using granulated activated carbon (GAC) are increasingly being deployed to eliminate trace substances from municipal wastewater. Working in conjunction with authorities and representatives from the field, Eawag has developed a document that will assist stakeholders with planning in relation to such measures.

The Verband zum Schutz des Greifensees (VGS) (Association for the Preservation of Lake Greifensee) elected its new Council of Delegates on 25 June 2020. In addition to representatives of all municipalities surrounding the lake, the committee also includes cantonal agencies, farmers, fishermen, sailors and – for the first time – a research representative, with the election of Eawag’s Piet Spaak as an aquatic ecologist.

Thanks to a new instrument, water pollutants can be measured automatically over a period of weeks – directly in the field, rather than in the laboratory. The mobile mass spectrometer is housed in a trailer and can be remotely controlled by smartphone.

126 Swiss researchers, including 6 from Eawag, want to draw the attention their Swiss compatriots to the scientific evidence showing the link between the emergence of pandemics and human disturbance of the natural environment.

Every year, the Swiss National Science Foundation launches a photography competition to select the best images from the world of science. In the category "The Research Project" the collage of a joint research project of Eawag and the Swiss Tropical and Public Health Institute was recognized.

The active ingredient diclofenac contained in various painkillers is hardly degraded at all in wastewater treatment plants and therefore accumulates in surface waters. There, amphipods convert diclofenac into a more toxic substance, namely diclofenac methyl ester, as shown in a study by the Swiss Federal Institute of Aquatic Science and Technology (Eawag).

Using a simple but ingenious strategy, a research team has successfully demonstrated how water quality downstream of wastewater treatment plants is influenced by a single pharmaceutical manufacturing site: as variations in the concentrations of compounds over time are dependent on production cycles, it is possible to distinguish between industrial and household emissions – even a long way downstream.

Degradation products of the fungal agent chlorothalonil are found widely in groundwater on the Swiss Plateau, even in places where it is used as drinking water. Dealing with these substances is becoming a challenge for waterworks. There is a wide range between rash immediate measures and concealing the problem. An Eawag fact sheet serves to contribute to an objective discussion and longer-term strategies.

The measurement of trace concentrations of pyrethroid and organophosphate insecticides – now possible thanks to a newly developed analytical method – shows that these compounds can pose a greater threat to aquatic organisms than all other pesticides.

Swiss groundwater contains numerous pesticide degradation products. This has been discovered by an extensive screening by Eawag and ETH Zurich. The transformation products (metabolites) originate predominantly from pesticides from agriculture.

Phosphate supplies are limited and found in only a few countries. Mining and transport of this nutrient are costly. It is therefore becoming increasingly important that phosphorus be recovered and reused regionally, and Switzerland, with a functioning phosphorus recycling economy, can lead the way.

Without phosphorus there would be no life; however, the mineable quantities are limited. The element was first described 350 years ago. This week, some 200 experts are meeting in Zurich to discuss the future of phosphorus.

Some insecticides, such as the neonicotinoids, have an effect on the nervous systems of organisms. But not only, as shown by the results of a new study in which Eawag scientists took part. And: the resulting damage can be very different, depending on the species of fish.

Climate change will also have an effect on the surface waters and aquatic ecosystems of Switzerland. The extent of this effect has now been examined by Eawag researchers in a synthesis report commissioned by FOEN. All in all, it will be possible to maintain the high quality of Swiss waters through management and adaptation, however, this will entail higher costs, say the authors of the report.

Two studies by Eawag and the Ecotox Centre have once again shown that surface waters in agricultural catchment areas are heavily contaminated with plant protection products. Concentrations of individual substances persisting for several months pose a risk of chronic toxicity and, for extended periods, exceed the levels at which a risk of acute toxicity exists for aquatic plants and organisms. In most of the samples, 30 or more different active ingredients were detected. Studies of stream biodiversity and bioassays confirmed the threat posed by these mixtures of substances.

Freshwater lakes are teeming with blue-green algae that produce a heady cocktail of substances. Little is known as yet about the health risks associated with these substances, although a review of the literature by Eawag scientist Elisabeth Janssen has now revealed some potentially harmful effects.

A new study by an interdisciplinary team from Eawag has shown that substances from agriculture affect living organisms in rivers and streams to a greater extent than treated wastewater, which has less impact on the species composition of microorganisms.