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

The presence of methyl orange (MO) and ciprofloxacin (CIP) in wastewater poses a serious threat to the environment and human health. Titanium dioxide nanoparticles (TiO 2 NPs) are widely studied as photocatalysts for wastewater treatment. However, TiO 2 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-TiO 2 /PVDF) membranes were successful prepared in this work by combining the modified sol-gel method and the immersion phase inversion method. The Eu-TiO 2 /PVDF membranes obtained with the increase of Eu-TiO 2 NPs content during the preparation process were named M1, M2 and M3, respectively. The pure PVDF membrane without the addition of Eu-TiO 2 NPs was named M0, which was prepared by the immersion phase inversion method and served as a reference. The prepared Eu-TiO 2 /PVDF membranes could not only adsorb MO, but also degrade CIP under visible-light irradiation. Moreover, the Eu-TiO 2 /PVDF membranes exhibited adsorption-photocatalytic activity towards a mixture of MO and CIP under visible-light irradiation. Last but not the least, the Eu-TiO 2 /PVDF membranes exhibited excellent recyclability and reusability, opening the avenue for a possible use of these membranes in sewage-treatment plants. The Eu-TiO 2 /PVDF membrane can adsorb the organic dye methyl orange (MO), degrade the antibiotic ciprofloxacin (CIP) under visible-light irradiation, and simultaneously adsorb and degrade a mixture of MO and CIP.