Polymeric membrane technologies for wastewater treatment and valorization: Advancing sustainable and circular water systems

Water represents the essence of life, but its quality is under risk due to different discharges of industries, waste from agriculture, and wastewater without any treatment process. The guarantee of quality and its use have made water treatment a global pursuit, leading to the development of treatment methods. Among these, polymeric membrane techniques have been proved to be successful, versatile, and economical methods for water treatment. The purpose of this review is to highlight the advancements in various membrane-based treatment processes, such as reverse osmosis, nanofiltration, and ultrafiltration, with respect to the target contaminants, innovations, mechanisms, advantages, and limitations. The membrane separation process occurs on the basis of size exclusion, molecular diffusion, and electrostatic interactions, thereby making the process efficient for the removal of heavy metals, emerging contaminants, and other contaminants. In the article, it has been discussed that the application of polymeric membrane systems in the attainment of sustainable remediation in wastewater has been highlighted, specifically in terms of its potential contribution towards the effective tackling of the problem, including consideration of some challenges such as fouling, scaling, energy, and degradation, as well as some emerging techniques in membrane material design, fouling, and optimization. The valorization of wastewater in retrieving some solutes has also been discussed in the article, specifically in its integral contribution towards sustainability in some processes such as resource reuse and environment.