Polymeric membranes for sustainable closed-loop heamodialysis process water management: Recent advances and future perspectives

Hemodialysis (HD) is a life-saving kidney treatment process that requires a substantial amount of ultra-pure dialysate water to ensure patient safety. The global increase in prevalence of HD patients cases has led to a rapid rise in the demand for high-performing polymeric membranes used in HD process. This review provides a comprehensive overview of recent advancements in polymeric membranes for hemodialysis (HD), highlighting their critical roles in ultrapure dialysate production, efficient HD treatment performance, and regeneration of spent dialysate within a closed-loop system. It also addresses dialysate quality standards and underscores the importance of reversed osmosis (RO) and forward osmosis (FO) polymeric membranes in advancing sustainable and integrated dialysate management system. Furthermore, the performance of osmotically and pressure-driven HD membranes and various synthesis approaches for their fabrication are explored. The review critically examines different polymeric materials used in membrane production and evaluates the contribution of advanced materials such as novel carbon and biobased materials, metal-organic frameworks (MOFs), nanocomposites, metallic nanoparticles, carbon nanotubes (CNTs) etc to improve polymeric membranes performances for HD applications. Biocompatibility of HD membranes is highlighed as a crucial factor for dialysis treatment process, yet, efforts have been focused mainly, on hemocompatibility, despite broader biocompatibility landscape. Current limitations of RO and FO polymeric membranes applications in HD domain are enumerated while future research directions to overcome them are suggested. The need to develop sustainable closed-loop dialysate systems by integrating membrane technologies, material science, patient care, and environmental considerations is emphasized. More directed efforts are still required to create greener, higher biocompatible, and cost-effective membranes via integration of abundant, naturally occurring materials to meet the growing demands for achieving sustainable dialysate management.