Recent Progress in Microfiltration/Ultrafiltration Membranes for Separation of Oil and Water Emulsions

Oily wastewater has become one of the leading causes of environmental pollution. A massive quantity of oily wastewater is released from industries, oil spills, and routine activities, endangering the ecosystem's sustainability. Due to the enormous negative impact, researchers put strenuous efforts into developing a sustainable solution to treat oily wastewater. Microfiltration/ultrafiltration membranes are considered an efficient solution to treat oily wastewater due to their low cost, small footprint, facile operation, and high separation efficiencies. However, membranes severely fouled during the separation process due to oil's adsorption and cake layer formation, which shortens the membranes' life. This review has critically discussed the microfiltration/ultrafiltration membrane synthesizing methods and their emulsion's separation performance. In the end, key challenges and their possible solutions are highlighted to provide future direction to synthesize next-generation membranes.

Automated summary

Oily wastewater is a major cause of environmental pollution and poses a serious threat to the sustainability of ecosystems. Microfiltration/ultrafiltration membranes are considered an efficient solution for treating oily wastewater, although fouling caused by oil adsorption and cake layer formation reduces the lifespan of the membranes. This review critically discusses membrane synthesis methods and separation performance for emulsions, and highlights key challenges and potential solutions for synthesizing next-generation membranes.