Repurposing of End-of-Life Dialysate Production Polymeric Membrane for Achieving Sustainable Hemodialysis Process Water Management

Polymeric reverse osmosis (RO) membranes are critical for producing ultrapure water for hemodialysis process, but once they reach their end-of-life (EoL) stage, mainly due to fouling, they are usually discarded-adding to the growing challenges of medical waste management. This study explores a sustainable alternative by rehabilitating EoL thin-film composite (TFC) membrane and its reuse in recovery of spent dialysate. Using different cleaning agents that included citric acid (CA), EDTA, sodium lauryl sulfate (SLS), and sodium dodecyl sulfate (SDS), the mixture of CA and SLS (1:1) exhibited the most effective combination for balanced flux recovery, salt rejection, and creatinine clearance at lower TMP, achieving 90% conductivity reduction, 46.89 L/m²/h water flux, and 1.24 L/m²/h/bar permeance. FTIR, SEM, and EDX results confirmed the removal of both organic and inorganic foulants, while further process optimization revealed the critical role of cleaning temperature, SLS ratio and pressure on water permeability and improving creatinine removal. Under the optimal operational conditions, 99.89% creatinine removal, while restoring up to 80% hydraulic performance, yielding water flux and permeance of 59.36 L/m²/h and 1.79 L/m²/h/bar, respectively. These findings suggest that reduced dialysate production costs and minimize environmental impact can be significantly, achieved by extending the useful life of dialysate membranes, thereby opening a pathway toward implementing closed-loop water management and circular economy practices at dialysis centers.