Abbreviations 1 1 PA 6: polyamide 6, MB: Methylene Blue, IL: inline, DC: dip-coating, H: hydrophilic 2 ABSTRACT Titania has already proven its added value for air and water treatment. The higher the surface-to-volume area, the better the performance of the TiO2 photocatalyst. These nanoparticles are typically applied in a slurry form. The use of titania nanoparticles in suspension has, however, multiple disadvantages such as a high turbidity and complex recovery of the photocatalyst after use. Therefore, immobilization of titania nanoparticles on a porous support such as a nanofibrous membrane, can be highly valuable for water treatment. These TiO2 functionalized nanofibrous membranes may be used not only in a membrane separation reactor, but also in a contact reactor. In this study, TiO2 nanoparticles were immobilized on both polymer (polyamide 6) and ceramic (silica) nanofibrous membranes. Polymer nanofibers are chosen as they are the state-of-the-art material, silica nanofibers on the contrary are less studied but show additional advantages due their excellent chemical and thermal stability and can thus offer a clear benefit for a wider range of applications. Two immobilization techniques were used, namely inline functionalization and dip-coating. Inline functionalization showed to be the preferred method for polyamide 6 nanofibrous membranes, dip-coating for silica nanofibrous membranes. Complete degradation of isoproturon, an actual concern in water treatment, is shown. Even the widely available commercial TiO2 nanoparticles allowed for a complete isoproturon removal as the result of a correct immobilization process on nanofibrous materials. This clearly opens up the high value of TiO2 functionalized nanofibrous membranes for organic (micro)pollutants removal.