Stable hydrophilic and underwater superoleophobic ZnO nanorod decorated nanofibrous membrane and its application in wastewater treatment

Abstract

The usage of membrane technology is proving as a meaningful strategy in separating oil-water emulsion owing to their easy operations and low energy requirements. Herein, we propose a novel and effective route for fabricating a nanofibrous PVDF membrane decorated with ZnO nanorods for separating oil-water mixtures and emulsions. The superhydrophilic PVDF@ZnO nanorod surface with hierarchal micro-nano structures traps water molecules and exhibits underwater superoleophobicity. The applicability of the membrane in the separation process is justified by the high value of pure water flux and separation efficiency of around 99%. The PVDF@ZnO nanorod membrane displayed excellent superhydrophilic-underwater superoleophobic wetting behavior under harsh environmental conditions including acidic, alkaline, hot and cold mediums. The antifouling and self-cleaning characteristics of PVDF@ZnO nanorod membrane are observed from the recovery of initial flux performance after fouling under UV irradiation. In addition, the membrane is capable of successfully degrading organic and pharmaceutical pollutants present in oily wastewater. The multifunctional character of nanofibrous PVDF@ZnO nanorod membrane with its high performance in oil-water separation and capacity to degrade dissolved pollutants can be a good contender for potential use in wastewater treatment.