Oil-contaminated wastewater represents a major source of industrial pollution, posing significant risks to both the environment and human health. Traditional oil-water separation methods, including gravity separation, centrifugal separation, and air flotation, are limited by their processing efficiency and scope of applicability. In recent years, innovative oil-water separation technologies have gained considerable attention, particularly those utilizing adsorption, filtration, and membrane separation, owing to their high efficiency and environmental sustainability. Separation materials derived from biomass substrates-such as cellulose, chitosan, and lignin-along with metal-based membranes and polymeric filters, have shown remarkable performance. This is especially true for superhydrophobic/superoleophilic and stimuli-responsive materials, which excel in separating complex emulsified oil systems. This paper provides a comprehensive overview of the strengths and limitations of current separation technologies and explores the potential applications of multifunctional materials in treating oil-contaminated wastewater, offering both theoretical insights and practical guidance for advancing green, efficient oil-water separation solutions.
Keywords: biomass substrates; membrane separation; multifunctional separation materials; oil-contaminated wastewater; oil–water separation technology; superhydrophobic/superoleophilic materials.