Non-target analysis is used to characterize the fate of constituents of wastewater across the wastewater treatment train including ozonation and/or activated carbon treatment. In particular, locations with a certain contribution of industrial wastewater are investigated: WWTP Glarnerland (Glarnerland project), WWTP ProRheno (ProRheno, AktiFilt Plus project) and WWTP Altenrhein (AVA). Additionally, a suspect screening is performed to identify transformation products of ozonation (OTPs) and to study their fate in treatment with activated carbon. Bioassays are conducted to assess the water quality. The results contribute to the evaluation of different advanced treatment technologies, in particular related to the formation of OTPs and their elimination in the treatment with activated carbon.