Recent developments in ultrafiltration membrane technology for the removal of potentially toxic elements, and enhanced antifouling performance: A review

The presence of high concentrations of heavy metals (potentially toxic elements) in water bodies generates serious environmental issues and health problems that led to a dramatic increase in wastewater treatment costs. Therefore, it is imperative to develop low-cost and efficient technologies for removing these contaminants from wastewater. Membrane processes are advanced techniques for water treatment and ultrafiltration membrane (UF) has some advantages over other membranes as it requires low pressure to perform However, the UF membrane separates contaminants mainly by size exclusion mechanism, resulting in poor decontamination performance for potentially toxic elements and high susceptibility to membrane fouling. The performance of the UF membrane is often affected by organic and biofouling. Hence, researchers are still looking forward to developing new types of UF membranes that will make them more effective for potentially toxic elements removal and overcome the obstacle of fouling. This review aims to provide an overview of the application of UF membranes in potentially toxic element removal through bibliometric analysis and literature review. The incorporation of various organic, inorganic, carbon-based, and composite-based nano-materials into polymers such as zeolites, metal–organic frameworks (MOFs), and graphene oxide (GO) gave encouraging results for the removal of potentially toxic elements from water. Moreover, this review discusses the mechanisms of fouling in UF membranes and how different techniques can be used to control it. In the end, all the materials are evaluated and compared based on their efficiency, toxicity, simplicity in preparation, popularity, and cost efficiency to provide an overall critical view of the work done in this area. Also, the major challenges and limitations of the use of UF membranes are provided which will help to set the direction of future research.