Grantee Research Project Results
Novel Membrane Fabrication for Improved Flux, Reduced Fouling and Efficient Treatment of PFOA
EPA Grant Number: SU840401Title: Novel Membrane Fabrication for Improved Flux, Reduced Fouling and Efficient Treatment of PFOA
Investigators: Elliott, Mark
Current Investigators: Elliott, Mark , Jafarian, Hesam , Pilevar, Mohsen , Overton, Kylie , Bryant, Carolina , Williams, Delanie
Institution: The University of Alabama
EPA Project Officer: Spatz, Kyle
Project Period: July 1, 2022 through June 30, 2023
Project Amount: $24,953
RFA: 18th Annual P3 Awards: A National Student Design Competition Focusing on People, Prosperity and the Planet (2021) RFA Text | Recipients Lists
Research Category: P3 Awards , Water
Description:
Perfluoroalkyl substances (PFAS) are emerging contaminants that are persistent in the environment, bioaccumulative, and toxic even at trace concentrations. Widespread use of PFAS in diverse industries has led to extensive groundwater contamination. Because of their unique physicochemical properties, such as strong carbon−fluorine bonds and low vapor pressure, PFAS are highly resistant to degradation. However, extensive evidence suggests their adverse environmental and health effects. Consumption of these materials is reported to damage the endocrine system, liver, and kidney, increase cholesterol, and fetal exposure can lead to growth stunting and IQ loss, etc. In 2016, EPA released the lifetime health advisory levels of 70 ng/L for total perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) in drinking water; such a low threshold indicates substantial public health concerns. While regulatory guidelines and limits vary across countries, published values for PFOA and PFOS concentration are consistently among the lowest for any chemical compound.
Objective:
In this project, we demonstrate the fabrication of a metal-organic framework (MOF) embedded ultra-thin film nanocomposite (UTFN) membrane with tailored rejection of PFOA and scale-forming cations from feed solutions simulating groundwater. The innovative aspects of this project can be summarized in two categories of fabrication-modification technique and application performance. In this project, a novel proprietary approach is used as a method for interfacial polymerization (IP) of polyamide layer. Our method reduces chemical use for IP up to 98% with PFOA rejection >95%. The resulting UTFN membrane yields flux double that of conventionally fabricated membranes and four-times that of commercial NF270 membranes. Addition of silver-based MOF (Ag-MOF) also provides the membrane with antimicrobial properties and more negative surface charge. Such functionalized nanofiltration (NF) membranes have countless applications, yielding high water recovery, resistance to fouling, less frequent replacement, decreased operational costs, and decreasing environmental impacts associated with brine management.
Approach:
Removal of emerging industrial and commercial contaminants from water is of increasing importance. However, many current separation processes do not provide the required efficiency for removal of all specific contaminants such as PFOA; for those that do, cost, energy use, flux and fouling limit their application. Decreasing energy use, increasing flux, decreasing capital and operating costs, and enabling extended operation prior to membrane replacement would greatly expand use of membrane-based treatment. PFOA in wastewater with high levels of organic pollutants, toxicity, and carcinogenicity are a severe threat to people and the planet. From an industrial viewpoint, the environmental regulations for point source pollution are increasingly strict, therefore an efficient and affordable removal technology can save cost and enhance prosperity.
Membrane-based separation processes provide a reliable, flexible, and environmentally friendly approach for the removal of contaminants from wastewater. The main limiting factors of membrane-based separation are (1) the tradeoff between rejection and permeance and (2) fouling. Therefore, there is a need to fabricate or modify the anti-fouling membranes for enhanced water flux without sacrificing the rejection performance of the membranes.
Our preliminary testing indicates that the proposed Ag-MOF UTFN membranes can remove more than 95% of PFOA from water and wastewater with more than 300% increase in permeance versus current commercial NF membranes with approximately 98% decline in chemical usage. Our recent publications demonstrate that Ag-MOF nanoparticles can substantially inhibit biofouling and organic fouling. In this project, our research team will synthesize the Ag-MOF nanoparticle and incorporate it to the UTFN layer of polyamide membrane surface through our novel fabrication process. The fabricated functionalized membranes will be tested for removal of three targeted contaminants including PFOA, sodium sulfate (Na2SO4) and sodium chloride (NaCl). Co-PI Wujcik’s team will investigate the surface chemical and physical properties of the membranes. Co-PIs Tick and Liang will characterize and analyze PFOA. Our team will present our results at university, regional and national conferences and seminars to raise awareness of these issues and affect change.
Expected Results:
Phase I efforts will focus on the examination of the membranes’ rejection and water flux for selected contaminants including PFOA, Na2SO4, and NaCl individually at lab scale. Written outputs will include the Phase I report to EPA and Phase II proposal, with journal publications to follow the completion of Phase I. During Phase II, our long-term goal for this research is to increase the antifouling capability of the fabricated membranes for longer operation time.
Supplemental Keywords:
drinking water, innovative technology, adsorption, separationProgress and Final Reports:
The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.