Loose nanofiltration membranes for selective rejection of natural organic matter and mineral salts in drinking water treatment

Journal of Membrane Science, Journal Year: 2022, Volume and Issue: 662, P. 120970 - 120970

Published: Sept. 6, 2022

Language: Английский

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Modeling Water Transport in Interlayered Thin-Film Nanocomposite Membranes: Gutter Effect vs Funnel Effect

ACS ES&T Engineering, Journal Year: 2022, Volume and Issue: 2(11), P. 2023 - 2033

Published: Aug. 26, 2022

Interlayered thin-film nanocomposite (TFNi) membranes have experimentally demonstrated a great potential for achieving major gains in water permeance over conventional composite membranes, making them promising candidates many environmental applications. Nevertheless, existing literature often reports contradicting observations on the effectiveness of interlayers. In this study, we implement three-dimensional solution-diffusion model to analyze geometry-induced funnel effect and an interlayer-promoted gutter effect. Our simulation results suggest that even ultrathin interlayer few nanometers thickness could serve as low-resistance layer, which minimizes transversal transport less permeable polyamide layer thereby mitigate unfavorable The actual available is bounded by ideal polyamide-limited upper bound substrate-limited lower bound, with regulating competition between Water can be potentially improved order magnitude interlayer, enhancement more pronounced thinner layers, porous substrates, We further role improving flux distribution/uniformity membrane surface, has implications fouling propensity. study establishes theoretical framework understanding fundamental mechanisms TFNi provides important guidance future development high-performance desalination membranes.

Language: Английский

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Cosolvent-Assisted Interfacial Polymerization toward Regulating the Morphology and Performance of Polyamide Reverse Osmosis Membranes: Increased m-Phenylenediamine Solubility or Enhanced Interfacial Vaporization?

Environmental Science & Technology, Journal Year: 2022, Volume and Issue: 56(14), P. 10308 - 10316

Published: June 29, 2022

Cosolvent-assisted interfacial polymerization (IP) can effectively enhance the separation performance of thin film composite (TFC) reverse osmosis (RO) membranes. However, underlying mechanisms regulating formation their polyamide (PA) rejection films remain controversial. The current study reveals two essential roles cosolvents in IP reaction: (1) directly promoting vaporization with lower boiling points and (2) increasing solubility m-phenylenediamine (MPD) organic phase, thereby indirectly reaction. Using a series systematically chosen (i.e., diethyl ether, acetone, methanol, toluene) different MPD solubilities, we show that surface morphologies TFC RO membranes were regulated by combined direct indirect effects. A cosolvent favoring (e.g., point, greater solubility, and/or higher concentration) tends to create apparent thickness layer, larger nanovoids within more extensive exterior PA layers, leading significantly improved membrane water permeance. We further demonstrate potential achieve better antifouling for cosolvent-assisted provides mechanistic insights into critical reactions, providing new tools tailoring morphology properties toward efficient desalination reuse.

Language: Английский

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Demystifying the Role of Surfactant in Tailoring Polyamide Morphology for Enhanced Reverse Osmosis Performance: Mechanistic Insights and Environmental Implications

Environmental Science & Technology, Journal Year: 2023, Volume and Issue: 57(4), P. 1819 - 1827

Published: Jan. 18, 2023

Surfactant-assisted interfacial polymerization (IP) has shown strong potential to improve the separation performance of thin film composite polyamide membranes. A common belief is that enhanced attributed accelerated amine diffusion induced by surfactant, which can promote IP reaction. However, we show membrane for Tween 80 (a surfactant), even though it decreased diffusion. Indeed, closely related its roughness features with numerous nanovoids. Inspired nanofoaming theory relates nanobubbles degassed during reaction, hypothesize surfactant stabilize generated tailor formation Accordingly, obtained enlarged nanovoids when was added below critical micelle concentration (CMC). In addition, both permeance and selectivity were enhanced, thanks reduced defects in layer. Increasing above CMC resulted shrunken deteriorated performance, be ascribed stabilization effect caused formation. Interestingly, better antifouling also observed surfactant-assisted Our current study provides mechanistic insights into role may have important implications more efficient membrane-based desalination water reuse.

Language: Английский

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Does Surface Roughness Necessarily Increase the Fouling Propensity of Polyamide Reverse Osmosis Membranes by Humic Acid?

Environmental Science & Technology, Journal Year: 2023, Volume and Issue: 57(6), P. 2548 - 2556

Published: Jan. 31, 2023

Surface roughness has crucial influence on the fouling propensity of thin film composite (TFC) polyamide reverse osmosis (RO) membranes. A common wisdom is that rougher membranes tend to experience more severe fouling. In this study, we compared behaviors a smooth membrane (RO-s) and nanovoid-containing rough (RO-r). Contrary traditional belief, observed for RO-s, which can be ascribed its uneven flux distribution caused by "funnel effect". Additional tracer filtration tests using gold nanoparticles revealed patchlike particle deposition pattern, confirming adverse impact effect" water transport. contrast, experimentally lower explained by: (1) weakened thanks presence nanovoids, regulate transport pathway through (2) decreased average localized over surface due increased effective area nanovoid-induced features. The current study provides fundamental insights into critical role in fouling, may have important implications future development high-performance antifouling

Language: Английский

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Nanofoaming by surfactant tunes morphology and performance of polyamide nanofiltration membrane

Desalination, Journal Year: 2023, Volume and Issue: 552, P. 116457 - 116457

Published: Feb. 9, 2023

Language: Английский

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Making waves: Why do we need ultra-permeable nanofiltration membranes for water treatment?

Water Research X, Journal Year: 2023, Volume and Issue: 19, P. 100172 - 100172

Published: Feb. 20, 2023

Over the last few decades, developing ultra-permeable nanofiltration (UPNF) membranes has been a focus research area to support NF-based water treatment. Nevertheless, there have ongoing debates and doubts on need for UPNF membranes. In this work, we share our perspectives why are desired We analyze specific energy consumption (SEC) of NF processes under various application scenarios, which reveals potential reducing SEC by 1/3 2/3 depending prevailing transmembrane osmotic pressure difference. Furthermore, could potentially enable new process opportunities. Vacuum-driven submerged NF-modules be retrofitted existing water/wastewater treatment plants, offering lower cost compared conventional systems. Their use in membrane bioreactors (NF-MBR) can recycle wastewater into high-quality permeate water, enables energy-efficient reuse single step. The ability retaining soluble organics may further extend NF-MBR anaerobic dilute municipal wastewater. Critical analysis development huge rooms attain improved selectivity antifouling performance. Our perspective paper offers important insights future technology, lead paradigm shift burgeoning field.

Language: Английский

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NaHCO3 addition enhances water permeance and Ca/haloacetic acids selectivity of nanofiltration membranes for drinking water treatment

Water Research, Journal Year: 2023, Volume and Issue: 242, P. 120255 - 120255

Published: June 20, 2023

Language: Английский

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Evaluation of nanofiltration and reverse osmosis membranes for efficient rejection of organic micropollutants

Journal of Membrane Science, Journal Year: 2023, Volume and Issue: 693, P. 122357 - 122357

Published: Dec. 18, 2023

Language: Английский

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Enhancing the removal of organic micropollutants by nanofiltration membrane with Fe (III)–tannic acid interlayer: Mechanisms and environmental implications

Water Research, Journal Year: 2023, Volume and Issue: 245, P. 120623 - 120623

Published: Sept. 11, 2023

Language: Английский

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