News from the world of microplastics
12. March 2025
Microplastic analysis and water monitoring
11. April 2025
The Alb River around Karlsruhe is the first river to be sampled for microplastics from its mouth to its source
The Alb River is around 55 kilometres long, flowing from the northern Black Forest near Bad Herrenalb, to where it flows into the Rhine. It flows through towns, including a spa town, smaller villages, industrial areas, and nature reserves. It is the lifeline around Karlsruhe and is home to a wide variety of flora and fauna.
The Alb River was the target of our first major microplastic mapping at the beginning of March. We are not only a GreenTech start-up from Karlsruhe that is known for its technological innovations, we are also breaking new ground in the fields of education and transparent communication for more water without microplastics.
Class 8c of the Albertus-Magnus-Gymnasium Ettlingen was part of the microplastic mapping of the Alb © AMG Ettlingen
Unique business model includes all stakeholders
We are also known as the changemakers among entrepreneurs. Our transformative business model, the clear “Planet and People First” focus in our overall orientation, and continuous impact measurements are not only exciting for industries and municipal wastewater treatment plants, which benefit from the new developments in the field of microplastic detection and the removal and recycling of microplastics from wastewater, but our new ESD-certified microplastics seminar series, diverse teaching/learning materials, and age-independent hands-on activities also provide real solutions to the microplastics crisis. Suitable for everyday use and for everyone.
More data thanks to rapid microplastic detection
For years, all communication and explanations about microplastics were based on estimates. As a society, we already know that microplastics are a global environmental problem, but standardized microplastic analysis, which not only helps to obtain data but also guarantees data comparability, has been lacking – until now. Because only with comparable data can meaningful political regulations be achieved.
We see it as our task to obtain and interpret this data on microplastics and summarise it for everyone to understand. The cornerstone of our external communication on microplastics in water is the Global Map of Microplastics. This is an interactive map that makes microplastic pollution visible. “Everyone can help with the sampling. A validated standard protocol makes it possible. Not only are we able to take and evaluate samples from many places around the world at the same time, but we can also talk about real figures instead of estimates,” explains Katrin Schuhen.
The project “Tracking down microplastic together” is the first to focus on comprehensive microplastic sampling
Until now, the comprehensive sampling of an entire river within a short period of time with standardized microplastics analysis and sampling points at regular intervals has not been possible. There has also been a lack of comprehensive and comparable data packages. Although individual analyses provide information, there has been a lack of meaningful information and real options for action.
Microplastics are not evenly distributed in water
The term microplastics refers to synthetic polymer particles of all polymer types (there are more than 200 different types) with a size of less than 5 mm that occur in the environment - air, soil and water.
This diversity of different polymers and the millions of different plastic products mean that microplastic particles of different origins, compositions, shapes, and sizes are never evenly distributed in the environment. This is referred to as heterogeneity. As a counter-example: If, for example, a medicine dissolves completely in water, then it would be homogeneously distributed and a micropollutant.
“In order to capture this heterogeneity, we decided to sample upstream,” explains Katrin Schuhen, head of the study, author of the book "Rebellin des Wassers" and Managing Director of Wasser 3.0 gGmbH. “Of course, this meant that we had to cover a few meters in altitude, but it was worth the effort.”
The first river in focus: the Alb
Based on a standardized procedure for sampling, sample preparation and microplastic analysis, Wasser 3.0 gGmbH has been recording microplastic data for many years. While long-term monitoring has mainly taken place in municipal wastewater treatment plants, the method was also extensively validated and cross-validated for surface water analysis last year.
With the support of around 30 volunteers, including pupils from Albertus-Magnus-Gymnasium Ettlingen, we were also able to sample the first river - the Alb - every three to five kilometers from the mouth upstream to the source on three sunny days at the beginning of March. All volunteers were able to take standardized samples from the river using an analysis kit and the Wasser 3.0 app.
Classroom theory on microplastic mapping before heading to the water © AMG Ettlingen
How much microplastic is in the Alb?
A total of 23 samples were taken along the 55 km stretch, 20 of which were taken directly from the river and three from tributaries and lakes. All samples were analyzed for microplastics in the laboratory. The results are sobering.
Microplastics were found in all water samples from the Alb. With the known variances, depending on the location of the sampling site, the average was 99 particles per liter.
“We had hoped to find lower concentrations of microplastics at least at higher altitudes on the way to the source,” explains Katrin Schuhen. “Unfortunately, however, the entire river is contaminated.” The values confirm what the scientists suspected: The problem of microplastics in water is lurking right on our doorstep in our local waters. According to Katrin Schuhen, this is a reason to take action more quickly and in a meaningful way.
Impressions of microplastic sampling on the Alb © Wasser 3.0
Impressions of microplastic sampling on the Alb © Wasser 3.0
“We now know the status quo of a body of water - but it still remains a snapshot. It is a clear message to us that we need to take better care of our water bodies in the future and avoid pollutant inputs,” Katrin Schuhen continues. The next step for the scientists is to continue working with the data and identify causes and hotspots. Other rivers will also come into focus and be sampled comprehensively.
“We want to be real impact accelerators, giving politicians and experimenters the chance to take sensible measures for the future of our water today. It's not about apportioning blame but about making good decisions for society as a whole. This can start with the planning of the fourth purification stage for municipal wastewater treatment plants, where not only micropollutants but also the removal of microplastics are considered. Industries with high water requirements, waste and wastewater can also establish circular process flows. There are an incredible number of adjustments that can be made to tackle the microplastics crisis in a solution-oriented way.”
A big thank you to all contributors and encouragers
Many thanks to the students, teachers and interested parties for their commitment to microplastic mapping. Many thanks to the company Carl Roth GmbH + Co KG and to the private donors and sponsors. Without this financial support, the “Alles im Fluss” project would not have been possible.
