Photocatalytic membrane processes, and respective modelling, for removal of pharmaceutical residues in wastewaters. A case study with 2-[2, 6-(dichlorophenyl) amino] phenyl acetic acid as model molecule

Non linear modelling of data in photomineralization kinetics of organic micropollutants, by photocatalytic membranes immobilizing semiconductors (TiO2 particularly) has been previously applied to methane, phenol and to 2,4-dichlorophenol as model molecules, by using a four parameters kinetic modelling based on substrate disappearance and total organic carbon (TOC) in laboratory scale experiments, as a function of initial concentration of substrate and of irradiance. In the present paper, the photocatalytic degradation of diclofenac as model molecule was investigated in a pilot plant module, fitted with 2–3 concentric membranes. Maximum allowable quantum efficiencies corresponded to equal distances between 3 membranes immobilizing photocatalyst. This arrangement fully behaves as if a photocatalyst nanopowder would be homogeneously suspended in the reactor, but obviating all drawbacks of a nanopowder suspension.