Nanofiltration Membranes with Salt-Responsive Ion Valves for Enhanced Separation Performance in Brackish Water Treatment: A Battle against the Limitation of Salt Concentration
Nylons
Biological Transport
Sodium Chloride
6. Clean water
Nanospheres
DOI:
10.1021/acs.est.3c03919
Publication Date:
2023-09-15T11:09:19Z
AUTHORS (6)
ABSTRACT
Utilizing brackish water resources has imposed a high requirement on the design and construction of nanofiltration membranes. To overcome the limitation of high salt concentration on the nanofiltration separation performance resulting from the weakened Donnan effect, a nanofiltration membrane with the effect of salt-responsive ion valves was developed by incorporating zwitterionic nanospheres into the polyamide layer (PA-ZNs). The interaction between the nanospheres and membranes at high salinity was revealed through a combination analysis from the perspectives of water transport model, positron annihilation spectroscopy, and solute rejection, contributing to the formation of the valve effect. The PA-ZNs membrane presented a breakthrough in overcoming the limitation of increased salt concentrations on nanofiltration separation performance, achieving a high selectivity of 105 for mono/multivalent anions. To reveal the role of the ion valve effect in ion transport through the membrane, the membrane conductance was determined at different salt concentrations, confirming channel-controlled transport at low salinity and ion valve-controlled transport at high salinity. Moreover, the main membrane separation mechanisms were systematically studied. The concept of salt-responsive ion valves may contribute to expanding the application of nanofiltration in brackish water treatment.
SUPPLEMENTAL MATERIAL
Coming soon ....
REFERENCES (74)
CITATIONS (28)
EXTERNAL LINKS
PlumX Metrics
RECOMMENDATIONS
FAIR ASSESSMENT
Coming soon ....
JUPYTER LAB
Coming soon ....