Poly(vinylidene fluoride)/Nickel\nOxide–Montmorillonite\nMixed-Matrix Membranes for Oil Separation from Emulsified Oily Wastewater

Microemulsions originating from food industries, textiles,\npaint\nindustries, kitchen wastes, and oil spills on roads ultimately form\na complex cocktail of emulsified water sources that are difficult\nto separate. Traditional methods often fail to provide stable and\nefficient separation of these microemulsions at the tertiary stage,\nhighlighting the need for advanced membrane technologies. This study\nexplores the incorporation of nickel oxide and montmorillonite (NiO-MMT)\nnanoparticles into poly(vinylidene fluoride) (PVDF) membranes to enhance\nthe separation of microemulsified oil from water. By integrating 2%\nNiO-MMT, the membrane surface becomes significantly smoother compared\nto pristine PVDF membranes, thereby enhancing its antifouling properties.\nThe addition of NiO-MMT significantly improves the hydrophilicity\nof the membrane matrix, resulting in a pure water permeance of up\nto 3781 ± 3% L·m<sup>–2</sup>·h<sup>–1</sup>·bar<sup>–1</sup>. Experimental results indicate that\nNiO-MMT-incorporated PVDF membranes exhibit a >5.3 times increase\nin motor oil–water separation efficiency and a 1.4 times increase\nin the separation efficiency of both palm oil and mustard oil from\nwater compared to pristine membranes. The hydrophilic nature and high\nsurface energy of the composite membrane effectively separates stable\nmicroemulsified oil from water, achieving an 80% permeance recovery\nafter six filtration cycles. This contributes to environmental sustainability\nand technological advancements in various industrial applications.