Hydrophilic polymer-based membrane for oily wastewater treatment: a review

Abstract

Oily wastewater has been recognised as the most dangerous form of environmental pollution since the pollutant comes from a variety of sources and may harm humans, animals, plants, as well as the environment. Membrane technology is one of the most effective methods to overcome this phenomenon owing to its high separation efficiency and relatively simple operational processes. However, the challenging part to obtain clean water from oily wastewater using this technology is the fabrication of membranes with hydrophilic and antifouling characteristics. Conventional polymeric membranes are susceptible to fouling, which is caused by the interaction of oil molecules with the surfaces of the membranes and can render the excellent rejection performance and water flux. Thus, the wettability and antifouling properties of this membrane play an important role in the management of this issue. This review provides insights into recent approaches of various types of materials and methods applied in oily wastewater treatment for hydrophilic membranes. The findings from various types of membranes and modification techniques have also been discussed. Furthermore, the methods used to reduce the fouling issues within the membrane for oil/water emulsion separation are elaborated. Finally, the challenges faced in the development of membranes for commercial applications are identified and the future outlook is presented.