Bifunctional BiOCl/TiO2 decorated membrane for antibiotic photodegradation and oil-water emulsion separation

Abstract

Membrane separation is a simple and efficient technology for waste water treatment. However, organic pollutants such as antibiotics in complex water environment are hard to remove by the physical separation process. The coupling of photocatalysis and membrane separation can effectively remove the oil pollutants, meanwhile degrade the antibiotics. In this work, a composite membrane (BiOCl/TiO2@PAN) was prepared by the electrospinning technology and hydrothermal process. The membrane showed an excellent superhydrophilicity in air and an underwater superoleophobicity, thus it could separate a series of oil in water emulsions with a high permeability (231–613 L m-2h−1) without extra energy supply. Moreover, owing to the photoresponse ability of BiOCl and TiO2, the membrane could effectively degrade a variety of antibiotics including the typical antibiotic tetracycline, chlortetracycline, oxytetracycline and demeclocycline within 30 min under full-spectrum and visible light irradiation. Eight-cycle repeating experiments showed that composite membrane had an excellent stability and an efficiency in photocatalytic degradation and oil–water emulsion separation. Photo-responsive composite membrane prepared in this work showed a broad application prospect in treatment of complex sewage where oily waste and antibiotics simultaneously exist.