This oily wastewater has severe adverse effects on the environment, as previously witnessed during several oil spill accidents in the marine and terrestrial environments due to oil leakage from petroleum transport pipelines, storage tanks or transport facilities, and blowouts in oil wells. [3] The treatment of oily wastewater can be performed via numerous technologies such as adsorption, [4] dissolved air flotation, [5] coagulation, [6] gravity separation, [7] and biological treatment. [8] However, these methods have several limitations, such as low removal efficacy, high operational cost, high energy consumption, corrosion, and production of contaminated solid waste from spent adsorbents. [9] The rapid growth in separation technologies has resulted in various membranes that could overcome the shortcomings of other treatment methods. [10] Thus, membranes have become more desirable for oil/water separation for industrial applications because of their small footprint, environmental friendliness, cost-effectiveness, high productivity, low chemical consumption, automation capability, steady operation, and excellent separation efficiency. [11] Indeed, pore blockage or fouling remains among the major obstacles facing the membrane separation process since it decreases the flux, restricts the permeation rate, increases the energy consumption, and decreases the membrane lifetime. Therefore, substantial research efforts have been focused on enhancing the properties of membranes either via developing novel materials or introducing surface modifications for conventional membranes. [12,13] Although few reviews were published on oil/water separation membranes, they are either outdated or focused on a specific membrane type. This review features the most recent progress in membrane separation and its practical application in oil/water separation. It includes four sections that cover essential factors related to the advancement in membrane technologies are highlighted, including: 1) membrane properties and characterization for oily waste water separation; 2) the employed materials to fabricate membranes (i.e., metallic, organic, inorganic, and hybrid materials), 3) primary methods for designing membranes (i.e., mixed matrix nanocomposites and multilayers nanocomposites), and 4) membrane fabrication techniques and surface modification methods.
Membrane Properties and CharacterizationThe main objective of the oil/water separation membrane is to achieve high separation efficiency and excellent performance.Recent advancements in separation and membrane technologies have shown a great potential in removing oil from wastewaters effectively. In addition, the capabilities have improved to fabricate membranes with tunable properties in terms of their wettability, permeability, antifouling, and mechanical properties that govern the treatment of oily wastewaters. Herein, authors have critically reviewed the literature on membrane technology for oil/water separation with a specific focus on: 1) membrane properties and characterization, 2) d...
