In this master's thesis, flotation and electrochemical oxidation were investigated with regard to the concentration and following destruction of groundwater contaminated with PFOS. The question was which reagents in which concentrations are suitable for flotation and how they affect the PFOS concentration. Both organic and inorganic collectors and activators were used, as well as a biodegradable surfactant. The experiments took place in an agitated flotation system and follow-up experiments in a pneumatic flotation cell at the Chair of Mineral Processing. Knowledge from the treatment of aqueous PFOS solutions in connection with electrolysis with the formation of short-chain metabolites through electrochemical destruction is also part of this work.