In the past approximately 150 years, processes have been developed to remove the most substantial contaminants (carbon, nitrogen, phosphorus) from wastewater in treatment plants, mostly over the course of three stages. However, the industrial society has created pollutant classes that cannot be removed with these traditional methods. These pollutant classes include anthropogenic organic micro pollutants, e.g. traces of medicine, hormones, and industrial chemicals in high dilution. Communal treatment plants are trying to combat these with the so-called “fourth treatment stage” – so far, insufficiently. In places in which wastewaters emerge that have high concentrations of these pollutants, or also ions and salt loads, as well as agricultural residuals, the goal is to remove them before they are released into the water cycle, if possible. ThWIC targets these challenges with the projects in the field of innovation “Cleaning Water”.