Evolutionary biologists from the University of Tübingen investigate how water treatments affect fish
Even tiny amounts of toxins in rivers and lakes can endanger aquatic organisms. The public has become more aware of this environmental problem in recent years. Trace amounts of toxins found in our waterways are included in many of the things we use every day – dishwasher tablets, washing powder and shower gel – as well as pharmaceuticals, cosmetics, and pesticides.
These substances are in household wastewater and are transported to wastewater treatment plants, where conventional techniques cannot completely remove or degrade them. The treated wastewater flows into our streams, taking the toxins with it.
A group of researchers headed by the University of Tübingen’s Professor Rita Triebskorn has been investigating the effects of various wastewater treatments on the health of fish. The scientists, from the Institute of Evolution and Ecology (EvE), found that the type of wastewater treatment needs to be decided on a case by case basis, depending on the composition of toxins in the wastewater. Their study has been published in the journal Environmental Sciences Europe.
In conventional wastewater treatment plants the wastewater from industry and private households runs through mechanical, biological, and chemical purification stages. Additional stages using activated carbon or ozonisation are increasingly being included as a fourth purifcation stage.
“As part of an investigation on Lake Constance we were able to show that trace toxins can be effectively removed with an additional stage of powdered activated carbon, and that the health of aquatic organisms in the area clearly improves,” says Rita Triebskorn. “But until now there have been relatively few studies on the long-term success of improved wastewater treatment on water ecosystems.”
Standardized experimental conditions
In their comparative experiments the researchers looked at three conventional wastewater treatment plants – one of which, the Langwiese plant in the Ravensburg district, had an activated carbon stage installed during the study. The biologists placed cages into the water above and below the place where treated water from the plant flowed into the river.
“Compared with the examination of wild fish, this has the advantage that we can standardize the fish characteristics such as age, diet and stage of development. This means we can better recognize any effects on the health of the animals,” says team member and the study’s corresponding author, Sabrina Wilhelm. Established methods were used to find out whether the rainbow trout cell nuclei showed signs of increased genotoxicity. And the livers of the fish were examined to determine whether they were having to work harder to remove or break down toxins.
“While we didn’t find negative effects of trace toxins on fish health in one of the conventional water treatment plants, the rainbow trout below the second conventional plant had much higher critical liver values,” Sabrina Wilhelm says. “We also saw these negative effects at the Langwiese plant before the installation of the fourth stage.” She adds that the activated carbon stage clearly reduced the high liver values and the genotoxicity in the fish.
“Investing in modern water purification techniques are a boon to aquatic ecosystems particularly when conventional technologies don’t do enough to reduce the levels of toxins,” Rita Triebskorn says. “However, depending on the composition of the wastewater, negative effects on aquatic organisms can also be reduced by optimizing conventional wastewater purification.” The bottom line is that it is worth investing in good wastewater purification for sustainable protection of our environment.
Professor Dr. Rita Triebskorn
University of Tübingen
Institute of Evolution and Ecology
Phone +49 7071 29-78892
Sabrina Wilhelm, Stefanie Jacob, Michael Ziegler, Heinz-R. Köhler, Rita Triebskorn: Which kind of wastewater treatment do we need to avoid genotoxicity and dioxin-like toxicity in effluent-exposed fish?. Environmental Sciences Europe, https://doi.org/10.1186/s12302-018-0154-0.
Dr. Karl Guido Rijkhoek | idw - Informationsdienst Wissenschaft
Despite government claims, orangutan populations have not increased. Call for better monitoring
06.11.2018 | Deutsches Zentrum für integrative Biodiversitätsforschung (iDiv) Halle-Jena-Leipzig
Increasing frequency of ocean storms could alter kelp forest ecosystems
30.10.2018 | University of Virginia
Researchers at the University of New Hampshire have captured a difficult-to-view singular event involving "magnetic reconnection"--the process by which sparse particles and energy around Earth collide producing a quick but mighty explosion--in the Earth's magnetotail, the magnetic environment that trails behind the planet.
Magnetic reconnection has remained a bit of a mystery to scientists. They know it exists and have documented the effects that the energy explosions can...
Biochips have been developed at TU Wien (Vienna), on which tissue can be produced and examined. This allows supplying the tissue with different substances in a very controlled way.
Cultivating human cells in the Petri dish is not a big challenge today. Producing artificial tissue, however, permeated by fine blood vessels, is a much more...
Faster and secure data communication: This is the goal of a new joint project involving physicists from the University of Würzburg. The German Federal Ministry of Education and Research funds the project with 14.8 million euro.
In our digital world data security and secure communication are becoming more and more important. Quantum communication is a promising approach to achieve...
On Saturday, 10 November 2018, the research icebreaker Polarstern will leave its homeport of Bremerhaven, bound for Cape Town, South Africa.
When choosing materials to make something, trade-offs need to be made between a host of properties, such as thickness, stiffness and weight. Depending on the application in question, finding just the right balance is the difference between success and failure
Now, a team of Penn Engineers has demonstrated a new material they call "nanocardboard," an ultrathin equivalent of corrugated paper cardboard. A square...
09.11.2018 | Event News
06.11.2018 | Event News
23.10.2018 | Event News
16.11.2018 | Health and Medicine
16.11.2018 | Life Sciences
16.11.2018 | Life Sciences