Elimination of trace organic chemicals (TOrCs) at small scale wastewater treatment plants (

Following the adoption of the revised EU Urban Wastewater Treatment Directive in November 2024, national legislation must also be adapted in Germany, focusing on an advanced wastewater treatment step. This is intended to reduce water pollution with trace organic chemicals (TOrCs). Processes for the removal of TOrCs have so far proven to be particularly effective in medium to large scale wastewater treatment plants (WWTPs). However, TOrCs removal can also be considered for smaller WWTPs in the 2,000-10,000 PE range, as these often discharge into very small and sensitive water bodies.
This project involves the development and testing of cost-effective and low-maintenance solutions for the TOrCs removal at small wastewater treatment plants. The Irschenberg WWTP (7,000 PE) was selected as a case study for the implementation of the project. As part of a new construction, the WWTP will be equipped with a process designed by us: The Biofilterplus is a vertical filter (VFCW) that contains a mixture of sand and granular activated carbon (GAC) to eliminate TOrCs.
For the simulation of the vertical filter at the Irschenberg WWTP, column experiments are carried out at the technical center of the chair. Based on these experiments, recommendations for the filling and operation of the filter in Irschenberg can be derived. Variables to be tested are, for example, the feeding regime (surge vs. continuous), the saturation state (saturated vs. unsaturated), the hydraulic residence time, and the elimination performance. Our filter design aims at creating selective pressure for the removal of TOrCs through the combination of biofiltration and adsorption, and to generate a long service life for the activated carbon.
The first phase of the project started in June 2022 and concludes with phase 2, which begins when the WWTP goes into operation and scientific monitoring of the large-scale technical Biofilterplus is started.