Efficient removal of methyl orange and ciprofloxacin by reusable Eu–TiO2/PVDF membranes with adsorption and photocatalysis methods

Abstract

The presence of methyl orange (MO) and ciprofloxacin (CIP) in wastewater poses a serious threat to the environment and human health. Titanium dioxide nanoparticles (TiO₂ NPs) are widely studied as photocatalysts for wastewater treatment. However, TiO₂ NPs have the drawbacks of high energy required for activation, fast electron–hole pair recombination and difficulty in recovering from water. To overcome these problems, europium decorated titanium dioxide/poly(vinylidene fluoride) (Eu–TiO₂/PVDF) membranes were successful prepared in this work by combining the modified sol–gel method and the immersion phase inversion method. The Eu–TiO₂/PVDF membranes obtained with the increase of Eu–TiO₂ NPs content during the preparation process were named M1, M2 and M3, respectively. The pure PVDF membrane without the addition of Eu–TiO₂ NPs was named M0, which was prepared by the immersion phase inversion method and served as a reference. The prepared Eu–TiO₂/PVDF membranes could not only adsorb MO, but also degrade CIP under visible-light irradiation. Moreover, the Eu–TiO₂/PVDF membranes exhibited adsorption–photocatalytic activity towards a mixture of MO and CIP under visible-light irradiation. Last but not the least, the Eu–TiO₂/PVDF membranes exhibited excellent recyclability and reusability, opening the avenue for a possible use of these membranes in sewage-treatment plants.