Within the framework of PAKauf , an adsorption stage with powdered activated carbon in accumulation mode (PAK-SBR) is being tested in semi-technical trials for further elimination of trace substances at the Neckarsulm wastewater treatment plant (AZV Unteres Sulmtal). The investigations are scientifically accompanied by the FG SWW by means of a simulation-based description of the process, in particular in order to be able to answer questions on the optimization of the cycle phases.