The aim of the RORe³ project is to develop a holistic recycling concept for reverse osmosis modules (RO modules). The motivation lies in sustainability by reducing the number of modules to be disposed after filtration performance losses affecting water flow and retention. In cooperation with IUTA (Institut für Umwelt & Energie, Technik und Analytik e.V.) and Weidner Wassertechnik GmbH, the challenges of the project lie in the analysis of fouling in end-of-life (EoL) reverse osmosis membranes, the removal of the fouling including the polyamide layer (PA layer) and the reuse as an ultrafiltration or nanofiltration membrane (UF or NF membrane). For the recycling of EoL membranes, test methods must first be developed that can confirm the integrity and general functionality of the modules without having to open them. If they are damaged, the modules cannot be reused as either UF or NF membranes. Reuse as an UF membrane is possible if the PA layer of a RO membrane is removed with sodium hypochlorite (NaOCl). In addition to the dose to remove the PA layer, it must also be ensured that the underlying polysulfone layer (PS layer) is not attacked by the NaOCl. A NF membrane should be accessible through a layer-by-layer coating (LbL coating) with polyelectrolytes. The challenge here lies in the fabrication of a membrane with high permeance and simultaneously high retention of salts and organic molecules. Once the relevant parameters have been researched on a laboratory scale, the results will be used to recycle entire, undamaged EoL modules in accordance with the desired requirements. Final (long-term) tests of the treated UF or NF modules are planned for this purpose.