Effect of solution ions on the charge and performance of nanofiltration membranes

npj Clean Water, Год журнала: 2024, Номер 7(1)

Опубликована: Март 30, 2024

Abstract Considering growing efforts to understand and improve the solute-specific selectivity of nanofiltration (NF) membranes, we explored ion-specific effects that govern charge performance a loose polyamide NF membrane is commonly used for solute-solute separations. Specifically, systematically evaluated zeta potential under different conditions pH, salinity, ionic composition, correlated obtained data with tested similar conditions. Our results identify p K both carboxylic amine groups bonded surface suggest highly polarizable chloride anions in solution adsorb polyamide, increasing its negative charge. We also show monovalent cations “stickiness” can neutralize extents due their varying tendency sorb polymer matrix or screen fixed carboxyl on surface. Notably, our correlation between measurements permeability experiments indicates substantial contribution ions Donnan exclusion membranes.

Язык: Английский

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Fit-for-Purpose Design of Nanofiltration Membranes for Simultaneous Nutrient Recovery and Micropollutant Removal

Environmental Science & Technology, Год журнала: 2021, Номер 55(5), С. 3352 - 3361

Опубликована: Фев. 17, 2021

Domestic wastewater is a valuable reservoir of nutrients such as nitrogen and phosphorus. However, the presence emerging micropollutants (EMPs) hinders its applications in resource recovery. In this study, we designed fabricated novel thin-film composite polyamide membrane, which enables highly selective nanofiltration (NF) that removes EMPs effectively while preserving permeate. By incorporating polyethylenimine an additional monomer to piperazine surfactant sodium dodecyl sulfate interfacial polymerization, precisely tuned membrane pore size, size distribution, surface charge. The resultant NF achieved desirable solute–solute selectivity between (rejection rate > 75%) nutrient N P ions < 25%). applying modified Donnan steric model with dielectric exclusion, takes distribution into consideration, demonstrate synergistic effect charge regulating selectivity. Designing membranes for fit-for-purpose treatment has great potential improve flexibility technologies can convert streams water resources.

Язык: Английский

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Toward Enhancing Desalination and Heavy Metal Removal of TFC Nanofiltration Membranes: A Cost-Effective Interface Temperature-Regulated Interfacial Polymerization

ACS Applied Materials & Interfaces, Год журнала: 2021, Номер 13(48), С. 57998 - 58010

Опубликована: Ноя. 24, 2021

Polyamide (PA) chemistry-based nanofiltration (NF) membranes have an important role in the field of seawater desalination and wastewater reclamation. Achieving ultrathin defect-free active layer via precisely controlled interfacial polymerization (IP) is effective routine to improve separation efficiencies NF membranes. Herein, morphologies chemical structures thin-film composite (TFC) were accurately regulated by tailoring reaction temperature during IP process. This strategy was achieved controlling (-15, 5, 20, 35, 50°) oil-phase solutions. The structural compositions, morphological variations, features fabricated studied detail. In addition, formation mechanisms featuring different PAs also proposed discussed. temperature-assisted (TAIP) method greatly changed compositions resultant PA A very smooth thin film obtained for at a low temperature; thus, high 19.2 L m-2 h-1 bar-1 water permeance 97.7% Na2SO4 rejection observed. With regard temperature, lower higher salt with fewer membrane defects achieved. Impressively, exhibited uniform coffee-ring-like surface morphologies. special surface-featured showed superior selected heavy metals. Rejections 93.9%, 97.9%, 87.7% Cu2+, Mn2+, Cd2+ observed optimized membrane. Three cycles fouling tests indicated that temperatures excellent antifouling behavior, whereas interface contributed tendency. study provides economical, facile, universal TAIP performances TFC environmental treatment.

Язык: Английский

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Recent Advances in the Theory and Application of Nanofiltration: a Review

Current Pollution Reports, Год журнала: 2022, Номер 8(1), С. 51 - 80

Опубликована: Янв. 20, 2022

Язык: Английский

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Boosting the Performance of Nanofiltration Membranes in Removing Organic Micropollutants: Trade-Off Effect, Strategy Evaluation, and Prospective Development

Environmental Science & Technology, Год журнала: 2022, Номер 56(22), С. 15220 - 15237

Опубликована: Ноя. 4, 2022

In view of the high risks brought about by organic micropollutants (OMPs), nanofiltration (NF) processes have been playing a vital role in advanced water and wastewater treatment, owing to membrane performance rejection OMPs, permeation water, passage mineral salts. Though numerous studies devoted evaluating technically enhancing removing various trade-off effect between permeance water/OMP selectivity for state-of-the-art membranes remains far from being understood. Knowledge this is significant comparing guiding development works toward cost-efficient OMP removal. work, we comprehensively assessed 88 NF membranes, commercialized or newly developed, based on their data published literature. The effectiveness underlying mechanisms modification methods tailoring properties turn mainstream polyamide (PA) thin-film composite (TFC) were quantitatively analyzed. was demonstrated abundant both experimental measurements machine learning-based prediction. On basis, advancement novel benchmarked upper-bound revealed commercial lab-made PA membranes. We also potentials current selectively separating OMPs inorganic salts identified future research perspectives achieve further enhancement removal salt/OMP

Язык: Английский

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