Investigations of nanomaterial-based membranes for efficient removal of contaminants from wastewater via membrane distillation: a critical review

The requirement for wastewater treatment is paramount in ensuring environmental sustainability and safeguarding public health. As industrialization and urbanization accelerate, the volume of wastewater generated continues to increase, containing a diverse range of pollutants and contaminants. Untreated wastewater poses serious threats to ecosystems, water bodies, and human communities, leading to pollution, waterborne diseases, and ecological imbalances. Effective wastewater treatment becomes essential to mitigate these adverse effects by removing or reducing pollutants before discharge into natural water sources. This process helps to preserve water quality, protect aquatic life, and maintain the overall health of ecosystems. Membrane distillation (MD) has emerged as a promising technology for wastewater treatment, offering an innovative approach to address the challenges associated with conventional treatment methods. In MD, a hydrophobic membrane serves as a selective barrier, allowing water vapor to pass through while preventing the passage of contaminants. This paper offers an extensive overview of the latest advancements in nanotechnology and membrane distillation applied in wastewater treatment. We will delve into different types of nanomaterials that have been used to enhance the properties of MD membranes, such as nanocomposites, nanoparticles, and nanofiber membranes. We also explore the mechanisms by which these nanomaterials improve the separation efficiency, anti-fouling properties, and durability of MD membranes. Additionally, we highlight the potential of hybrid membranes that combine different types of nanomaterials for further improving the performance of MD in wastewater treatment. We provide examples of recent studies that have investigated the use of hybrid membranes, including carbon nanotube-graphene oxide hybrid membranes, nanocomposite nanofiber membranes, and silver nanoparticle-embedded membranes. We also identify some areas for future research and development, such as the scale-up and commercialization of nanotechnology-based MD systems. In summary, this review paper highlights the potential of nanotechnology to enhance the performance of MD in wastewater treatment, leading to improved water quality and a cleaner environment.