Extending Swro Membrane Life And Controlling Biofouling Via Flux‑Balanced Operation Enabled By Interstage Boosting
Abstract:
Over the past decade, the operational lifetime of seawater reverse osmosis (SWRO) membranes has declined significantly, coinciding with industry trends toward higher system recoveries and longer pressure vessels. While higher recovery improves water production efficiency, it often results in excessive flux and recovery at the lead membrane elements, leading to increased concentration polarization, accelerated biofouling, and premature membrane degradation. This review examines the underlying hydraulic and osmotic imbalances in conventional single-stage SWRO designs and identifies excessive element-level flux as the primary driver of reduced membrane lifespan rather than high recovery itself. The study introduces and evaluates flux-balanced system concepts enabled by interstage pressure boosting, where net driving pressure is more evenly distributed along the membrane array. Several design scenarios—in cluding a theoretical element‑by‑element boosted system, three‑stage, two‑stage, and traditional single‑stage configurations—are analyzed and compared using membrane projection data. Results demonstrate that multi stage designs significantly reduce peak membrane flux, maintain element recovery within recommended lim its, and lower concentration polarization, thereby mitigating biofouling risks and extending membrane life. Among the practical options, the two‑stage system with interstage boosting, particularly when combined with Biturbo energy recovery technology, offers the most favorable balance between capital cost, operational effi ciency, membrane longevity, and energy consumption. These findings highlight flux-balanced operation as a critical design strategy for improving the sustainability and economics of modern SWRO plants.
