Pilot project for micropollutants removal at Rodenkirchen, Cologne (DE)

“Our objective with the 'AdOx Cologne' project is to determine the most effective and economical solution for trace substance removal using the existing biofiltration cells.”
— Dipl.-Ing. Manuel Hartenberger, Project Manager, “AdOx Cologne” (StEB)

Developing an Innovative Solution for Micropollutant Removal

Cologne’s municipal sewage company, Stadtentwässerungsbetriebe Köln (StEB), operates five wastewater treatment plants in the region, including one in Rodenkirchen. With growing regulatory and environmental pressures, StEB launched the "AdOx Cologne" project (Ad: Adsorption, Ox: Oxidation), funded by the Ministry of the Environment (MKULNV) of North Rhine-Westphalia. The aim is to develop a practical, cost-effective process solution for upgrading existing BIOFOR® filter systems to include micropollutant removal — without the need for major infrastructure changes.

Filtralite® Improves Filtration Capacity and Efficiency

In November 2017, Filtralite® NC 1.5–2.5 was introduced as the filter media for the project. Its unique porosity and internal structure significantly improve water flow through the filter bed, providing a larger surface area for the adsorption and retention of trace contaminants — all within the same filter volume. This property makes Filtralite particularly well-suited for retrofitting existing biofilters to meet future micropollutant removal requirements.

Collaborative Approach to Advanced Water Treatment

The project is a strong example of collaboration between public authorities, research institutions, and engineering experts.

• Dipl.-Ing. Manuel Hartenberger from StEB has led the initiative from its inception.
• Dr.-Ing. Frank Benstöm from the Institute for Urban Water Management (ISA) at RWTH Aachen University oversees the scientific monitoring, building on his extensive research background in wastewater filtration.
• Engineering partner Hydro-Ingenieure GmbH (Düsseldorf) contributes design expertise gained from numerous micropollutant removal projects.

Together, these partners are demonstrating how Filtralite®-based solutions can help utilities meet future environmental regulations while optimising existing infrastructure and keeping operational costs low.