Preparation of Janus membrane with self-cleaning functionality and membrane distillation performance

Abstract

Membrane distillation (MD) technology encounters problems such as membrane scaling, membrane wetting, and fouling during the reprocessing of diverse wastewater types. Janus membranes are anticipated to hold significant potential in addressing these issues. The metal-polyphenol network (MPN) was employed to mediate the catalytic self-cleaning ability of the intermediate mineralization layer as well as the PA-layered Janus membranes generated on the surface through the interfacial polymerization (IP) reaction. It was revealed that the pure water flux of the pristine PVDF membrane was 44.9 LMH, while that of the Janus membrane was 41.8 LMH. The PA layer of the Janus membrane is conducive to the increase of flux because of its hydrophilicity. However, excessive nanoparticles can block the membrane pores, and thus it compensates for part of the decreased flux to a certain extent. During the direct contact membrane distillation (DCMD) experiment, Janus membrane demonstrated superior performance in comparison to the PVDF membrane in the treatment of oily wastewater, saline solutions of sodium dodecyl sulphate (SDS), and gypsum-induced fouling. The mineralization layer based on manganese oxide can ensures higher stability of Janus membranes during cycling through in situ catalytic self-cleaning when dealing with the organic pollutant humic acid (HA). Overall, this study offers a novel and potential MD membrane.