Resource-saving and integrated activated carbon production at wastewater treatment plants for the elimination of trace substances

The aim of the RIAS project is to extract wastewater-borne organic substances from raw wastewater by screening, convert them into RAK (resource-saving activated carbon) and use them to eliminate trace substances in municipal wastewater treatment plants. In the project, municipal wastewater does not pass through a primary clarifier as usual, but is pre-treated mechanically by wastewater screening. Mechanical pre-treatment is to be optimised with regard to the recovery of valuable substances / screenings by using different screen mesh sizes. The screenings obtained are thermally treated using various processes (hydrothermal carbonisation (HTC) or pyrolysis), pelletised and activated in a rotary kiln. Alternatively, untreated, pelletised screenings are also activated directly.

The RAK produced is characterised in terms of its performance for the elimination of trace substances and compared with conventional activated carbon. The aim is to determine the most suitable process and the best process settings for converting the screenings into activated carbon optimised for the elimination of trace substances. In addition, tests will be carried out to desorb possible pollutants from the RAK. A life cycle analysis is used to determine the ecological footprint of the RAK produced. Mass balancing is used to assess the potential for the future self-sufficiency of wastewater treatment plants with regard to the production and use of RAK for the elimination of trace substances.