The goal of the FOEN project “Strategy Micropoll“ was to develop a strategy regarding micropollutants originating from wastewater. Besides an analysis of water quality in Switzerland and other aspects, this included the evaluation of the efficiency of complementary wastewater treatments such as ozonation followed by sand filtration (ozonation-SF) and different processes including powdered activated carbon addition (PAC) in eliminating micropollutants from wastewater treatment effluent. Two large-scale pilot studies were conducted at the wastewater treatment plants (WWTP) Wüeri in Regensdorf (ozonation followed by sand-filtration) and Vidy in Lausanne (ozonation followed by sandfiltration and PAC followed by ultrafiltration). The studies were done in close collaboration with experts from research, practice and with personnel and financial support of cantonal water protection agencies (Gewässerschutzfachstellen) and the operators of the WWTPs.
In both studies, samples before and after various treatment steps were analysed for micropollutants and ecotoxicological effects, in order to get insight into the efficiency of the different treatment steps. The focus laid on studying the effects of the advanced treatment technologies, ozonation and PAC, on the removal efficiency for polar, persistent and bioactive substances as well as possible side products and their biological effects. [...]