pH-Induced non-fouling membrane for effective separation of oil-in-water emulsion

Membrane technology has been considered as one of the most efficient methods to treat oil contaminated water. However, due to serious fouling caused by oil droplets absorption, the development of membrane technology is impeded in treating oily wastewater. We report in this work the fabrication of a pH-induced non-fouling membrane by grafting hyperbranched poly (ethylene imine) (PEI) onto PVDF/polyacrylic acid grafted PVDF blend membrane for effectively separating viscous soybean oil-in-water emulsion. The membrane exhibits an ultralow oil-adhesion and thus displays a superior antifouling performance in acidic condition so that it maintains a stable flux for long-time permeating. Meanwhile, the PEI grafted blend membrane behaves an excellent permeating performance with high flux and high separation efficiency. It shows a promising potential for treating oil-contaminated wastewater produced by various industrial processes, especially for acidic oily wastewater treatment.