The river Schussen flows through the three districts of Biberach, Ravensburg and Lake Constance on its approximately 60-kilometre route and flows into Lake Constance at Eriskirch. In the last 17.5 kilometers before it flows into the Swabian Sea, the Schussen takes in around 20 tributaries.

In order to improve the condition of the water bodies in the association's area and achieve the objectives of the EU Water Framework Directive in the Schussen catchment area in the Lake Constance district, the Lower Schussental Wastewater Association commissioned a comprehensive aquatic ecology report. This was completed in 2020 and shows that engineering measures are required. The association is being supported in the scientific design of these measures by Biberach University of Applied Sciences and other project partners.

In addition to the experts from Biberach University of Applied Sciences, other partners are also involved in the development of the soil filter. Cooperation with specialists who have local knowledge of the wastewater association's drainage system (Wasser-Müller Ingenieurbüro GmbH in Biberach) and the watercourse (Gewässerplan office in Kressbronn am Bodensee) as well as extensive experience with the use of granulated activated carbon in wastewater treatment (Jedele und Partner engineering office in Wangen im Allgäu) is essential. The involvement of the water management authority (Bodenseekreis district office) and the local operating personnel (Abwasserverband Unteres Schussental) is also of great importance for the project participants.

In addition, the Baden-Württemberg Competence Center for Trace Substances at the Institute for Sanitary Engineering, Water Quality and Waste Management at the University of Stuttgart is involved to support the research team with sampling and micropollutant analysis, as is the teaching and research laboratory of the Institute for Sanitary Engineering, Water Quality and Waste Management at the University of Stuttgart.

When it rains, residential wastewater flows directly into bodies of water such as the Schussen and pollutes them. In order to reduce this pollution, retention basins are built and soil filters are used. Nevertheless, problematic substances remain in the water. The project therefore focuses on the development of a retention soil filter that can specifically remove micropollutants such as mecoprop, diclofenac, carbamazepine and metoprolol.

The Institute for Applied Biotechnology at Biberach University of Applied Sciences, which is also represented in the ITZ Plus and was already involved in the water studies at the start of the project, is responsible for identifying the micropollutants and optimizing and possibly expanding the screening procedures.

The aim of the research project is the long-term integration of soil filters into the nationwide water infrastructure to improve water quality and overcome the challenges posed by micropollutants. The project is funded by the Tübingen Regional Council and the Baden-Württemberg Ministry of the Environment.

Author and contact person at ITZ Plus: Tim Hamann, hamann@hochschule-bc.de; Project management: Ulrike Zettl