Naturally derived materials to enhance the membrane properties in (waste)water treatment applications - Mechanisms, scale-up challenges and economic considerations

Membrane separation technologies are currently considered among the leading technologies for the treatment of polluted (waste)water in terms of treatment efficiency and ease of implementation. However, their wider applications, especially for real wastewater treatment, have been restricted by some bottlenecks, including rapid fouling, low stability, and high production costs. Recently, naturally derived materials including carbonaceous materials (e.g., biochar, activated carbon, carbon nanotubes, graphene and graphene oxide, and carbon quantum dots), clay (e.g., bentonite, kaolinite, and zeolite), and natural polymers (e.g., cellulose and chitin) have been employed for the modification of membrane structures to improve the properties required for efficient (waste)water treatment (e.g., water permeability, hydrophilicity, antifouling) and performance (e.g., rejection efficiency). The present review aims to summarize and discuss the literature available on the application of such naturally derived materials and their applicability for the large-scale fabrication of (waste)water filtration membranes. The existing challenges, scientific gaps, economic considerations, and regional development of membrane technologies have also been discussed, and recommendations have been provided for future studies to develop sustainable membrane structures, leading to a decrease in the overall treatment costs and enhancing the quality of treatment of effluents from industrial and nonindustrial sources.