Role of Transmembrane Pressure and Water Flux in Reverse Osmosis Composite Membrane Compaction and Performance

Environmental Science & Technology, Journal Year: 2025, Volume and Issue: unknown

Published: April 23, 2025

This study explores the compaction behavior of thin-film composite reverse osmosis (TFC RO) membranes for different combinations transmembrane pressure (TMP) and water flux. Operating a crossflow system at constant feed (60 bar) but solution osmotic pressures enabled adjusting TMP─the difference between hydraulic pressure─and The extent membrane increases as TMP (and flux) increases. Both commercial hand-cast TFC RO showed substantial high (up to 30% 50 bar TMP) compared less than 10% 10 TMP. Scanning electron microscope (SEM) images reveal direct relationship polysulfone (PSU) support layer compaction, while molecular dynamics (MD) simulations confirmed decreased porosity reduced thickness in polyamide (PA) active Combined findings from wet-testing MD confirm drop occurs across both PA meso-to-macro-porous layer; higher exacerbates layers resulting lower permeability flux, observed salt rejection, permeability. Transitioning low or vice versa did not notably alter compaction. observation is attributed highly cross-linked layer's ability recover after released, whereas PSU largely irreversible. While dictates overall gradient, our suggest that flux-induced frictional forces play crucial role dynamics. Specifically, flux generates additional drag on polymer matrix selective layer, intensifying structural deformation. Overall, offer critical insights into mechanisms providing foundation optimizing performance advancing next-generation technologies.

Language: Английский

Mechanistic insights into enhancing water transport and antifouling performance under high concentration polarization in polyamide membranes

Journal of Membrane Science, Journal Year: 2025, Volume and Issue: unknown, P. 124060 - 124060

Published: April 1, 2025

Language: Английский