Membrane Functionalization Approaches toward Per- and Polyfluoroalkyl Substances and Selected Metal Ion Separations
Francisco Léniz-Pizarro1,2, Holly E Rudel3,4, Nicolas J Briot1,5
1Department of Chemical and Materials Engineering, University of Kentucky, Lexington, Kentucky 40506, United States.
ACS Applied Materials & Interfaces
|September 9, 2023
Summary
Pore-functionalized membranes overcome diffusion limitations in water purification, offering faster kinetics and higher capacity than traditional methods for removing contaminants like arsenic and PFAS.
Area of Science:
- Materials Science
- Environmental Engineering
- Chemical Engineering
Background:
- Adsorption and ion exchange are key water purification methods but face diffusion limitations.
- Pore-functionalized membranes offer a potential solution to enhance separation efficiency.
Purpose of the Study:
- To systematically evaluate the benefits and applicability of adsorptive/ion exchange (IX) pore-functionalized membranes.
- To synthesize and test novel functionalized membranes for diverse pollutant removal.
Main Methods:
- Synthesized three types of adsorptive/IX polymers (strong/weak acid, strong base, iron-chitosan) within microfiltration (MF) membrane pores.
- Tested membrane performance for removing arsenic, PFAS, and calcium from water.
- Compared functionalized membranes with traditional resin beads and crushed resins.
Main Results:
- Functionalized membranes showed higher sorption capacity and up to 100x faster kinetics than conventional methods.
- Regeneration of membrane capacity ranged from 70-100%, concentrating solutions up to 12x.
- Theoretical capacities reached 550 mequiv/m², significantly exceeding the 175 mequiv/m² benchmark for competing with commercial IX resins.
Conclusions:
- Pore-functionalized membranes offer a versatile and effective approach to water purification.
- This technology significantly overcomes diffusion limitations inherent in traditional adsorption and ion exchange.
- The developed membranes present a promising solution for tackling diverse water contamination challenges.
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