In this work, for the first time, the stability of the TiO2 suspensions used for the photocatalytic membrane preparation was studied by considering the Turbiscan Stability Index (TSI). The use of a stable suspension during the membrane preparation (by the dip-coating method) permitted a better dispersion of the TiO2 nanoparticles into the membrane structure due to a reduction of agglomerates formation. The dip-coating was performed on the macroporous structure (external surface) of the Al2O3 membrane to avoid large reduction of the permeability. In addition, the reduction of the suspension infiltration along the membrane's cross-section allowed us to preserve the separative layer of the modified membrane. The water flux was reduced by about 11% after the dip-coating. The photocatalytic performance of the prepared membranes was evaluated using the methyl orange as a model pollutant. The reusability of the photocatalytic membranes was also demonstrated.
Keywords: Turbiscan Stability Index; alumina tubular membrane; methyl orange; titanium dioxide.