The Civil Engineering Department of the City of Giessen , a working group from the Giessen -Friedberg University of Applied Sciences led by Prof. Dr.-Ing. Ulf Theilen, and the Sonthofen-based engineering firm for drainage, sewage treatment plants, and control (iaks) are collaborating on a research project. The German Federal Environmental Foundation is funding the work with over €200,000. This research project, unique in Germany, aims to optimize Giessen 's wastewater disposal system.

In many drainage networks, it is difficult or impossible to control the flow behavior of the sewer system in conjunction with the wastewater treatment plant in a situation-appropriate and environmentally sound manner. As a result, unnecessarily high pollutant loads are often discharged into waterways. Furthermore, the retention basins intended for rainwater are often oversized, driving up costs.

This situation prompted the Giessen city civil engineering department to seek competent partners in Germany to solve the problem. Based on the existing positive collaboration with the Department Civil Engineering at the Giessen -Friedberg University of Applied Sciences, integrating their expertise into the research project was a logical step. Furthermore, the engineering firm iaks, which possesses extensive experience in this field, was brought on board as the research team and is now responsible for the technical and organizational project management.

The current joint project aims to improve the operation of the Giessen wastewater treatment plant to increase its treatment efficiency and reduce operating costs. A process engineering solution is being developed for the water flowing through the sewer network, which will reduce the frequently necessary discharge of untreated combined sewage and rainwater into rivers during heavy rain. The project leaders, including Prof. Theilen, who teaches urban water management at the university of applied sciences, Clemens Abel, head of the civil engineering department, and Martina Scheer, engineer at the engineering firm iaks, see this as another significant step towards improving the water quality of the Lahn River.

The planned control system will be developed based on measurements of flow rates and pollutant concentrations for the drainage system of the city of Giessen and its surrounding areas. It will be tested in practice and serve as a model for the systems of other municipalities. The stakeholders aim to achieve a number of environmentally relevant goals: among other things, the proportion of untreated combined sewer overflow will be reduced as much as possible, and the inflow to the wastewater treatment plant will be regulated according to its current load (volume and pollutant load).

The engineering firm iaks is calculating the expected improvements in wastewater treatment plant performance using a computer simulation that explores various flow control scenarios. The focus of the university of applied sciences (FH) staff's research is the continuous monitoring and analysis of pollution levels. To this end, they will take samples during the test phase and use online probes, the results of which will be used to calibrate the computer simulation. Another research focus of this project is the evaluation of the effectiveness of various systems for sewer treatment.