Radiation therapy produces wastewater, which can contain considerable amounts of radioactivity. Up to 90% of the dose administered can enter the wastewater. With conventional methods, the load of the wastewater is reduced through radioactive decay (natural decomposition of the isotope), an often complex and very expensive process. The BioChroma method was developed by us as an alternative. It combines biological wastewater treatment with a final adsorption and filtration stage.