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Capability of nanofiltration membranes (NF) to remove pharmaceutical active compounds from wastewater streams was investigated. Sulfamethoxazole, diclofenac sodium, hydrochlorothiazide, 4-acetamidoantipyrine, nicotine and ranitinide hydrochloride were selected as model compounds since they are widely produced as pharmaceutical agents. Two commercially available polyamide nanofiltration membranes (NF-90 and NF-270 from Dow FilmTec) were tested. Solute retention by NF-90 membrane was very high in all cases (over 95%), whereas NF-270 retention systematically appeared lower ranging from 75% (nicotine) to 95% (ranitidine hydrochloride). Temporal evolution of flux decline was also investigated. The influence of physicochemical properties of both membrane and solutes on membrane performance was analyzed to explore the main solute-membrane interactions that determine the solute transfer across the membrane. The influence of operation pressure on NF-90 and NF-270 rejection was also studied.

TiO2 nanoparticles are of potential interest for nanofiltration membranes in view of flux increase and improved fouling resistance. Conclusions from published studies, however, cannot be translated to other applications because results depend on specific parameters of which the precise effect is still unknown. In this study, PES flat-sheet membranes were manufactured for wastewater treatment application. The effects of TiO2 nanoparticles as additive on the preparation of polyethersulfone (PES) blend nanofiltration membranes were investigated in terms of pure water flux, hydraulic membrane resistance (permeability) and solute rejection performance. A polyethersulfone (PES) membrane was modified by dispersing nanoparticles of titanium oxide (TiO2) in a PES solution. The membranes were prepared with 30 wt.% of polymer PES by phase inversion method. 1-Methyl-2-pyrrolidone and deionized water were employed as solvent and coagulant, respectively. Membrane fouling was explored with humic acids as a model organic...

The present work aims to study the viability of combining heterogeneous photocatalysis and nanofiltration as an innovative strategy to improve atrazine elimination from aqueous solution by advanced oxidation processes. In order to promote the photocatalytic oxidation of atrazine, the selective separation of the intermediate products was explored by means of membrane filtration. Two nanofiltration membranes (NF-90 and NF-270) were tested to study their performance for aqueous solutions of atrazine (2-chloro-4-ethylamino-6-isopropylamino-s-triazine), cyanuric acid (2,4,6-trihydroxy-1,3,5-triazine), desethyl-desisopropyl-atrazine (2-chloro-4,6-diamino-1,3,5-triazine) and ammeline (2-hidroxy-4,6-amino-1,3,5-triazine). The influence of membranes and solutes properties on the organic rejection and flux decline was evaluated. Experimental flux declines were systematically small, although the values obtained for NF-90 were slightly larger than those found for NF-270. The highest difference was observed in the cas...