1. In situ growth and crystallization of TiO2 on polymeric membranes for the photocatalytic degradation of diclofenac and 17α-ethinylestradiol.
- Author
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Dekkouche, Seghir, Morales-Torres, Sergio, Ribeiro, Ana R., Faria, Joaquim L., Fontàs, Clàudia, Kebiche-Senhadji, Ounissa, and Silva, Adrián M.T.
- Subjects
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PHOTODEGRADATION , *POLYTEF , *TITANIUM dioxide , *PHOTOCATALYSIS , *POLYMERIC membranes , *PHOTOCATALYSTS , *DICLOFENAC , *CRYSTALLIZATION - Abstract
[Display omitted] • TiO 2 was grown and crystallized on polysulfone, PTFE and PVDF membranes. • Diclofenac and 17α-ethinylestradiol were removed by adsorption and photocatalysis. • 17α-ethinylestradiol was preferentially adsorbed regardless of the membrane tested. • TiO 2 -polysulfone was the most active membrane for the removal of both pollutants. • TiO 2 -PVDF presented the highest stability in consecutive reaction cycles. TiO 2 in situ growth on three commercial membranes (polysulfone – PS, polyvinylidene fluoride – PVDF and polytetrafluoroethylene – PTFE) and its hydrothermal post-crystallization to transform TiO 2 into a photocatalytically-active phase, were investigated under mild synthesis conditions to preserve the textural properties of the supports. The membranes were successfully prepared and characterized by scanning electron microscopy, thermogravimetry analysis, N 2 physisorption, X-ray diffraction, and water contact angle measurements, among other techniques. Membrane supports with a more opened porosity and high hydrophilicity allowed to enhance the content and distribution of the anatase TiO 2 nanoparticles on the membrane surface. The efficiency and the permeate flux of the developed membranes were investigated to simultaneously remove diclofenac (DCF) and 17α-ethinylestradiol (EE2) from water by adsorption and UV–LED (light-emitting diode) photocatalysis under continuous recirculating mode. All TiO 2 membranes achieved removal efficiencies above 90% for both contaminants, EE2 being always preferentially adsorbed over DCF due to electrostatic repulsions between the DCF molecules and the surface of these membranes. The permeate flux of TiO 2 membranes was enhanced after UV-LED exposure as a consequence of the degradation of the contaminants adsorbed on the membrane surface during the dark phase. Moreover, the stability of TiO 2 nanoparticles on these membranes was studied by static tests under sonication and several consecutive reaction cycles. The TiO 2 membrane prepared with PVDF was the most stable, also presenting a high photocatalytic activity. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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