Grantee Research Project Results
Final Report: Synthesis and Characterization of Fluorinated Hydrocarbon Anion Exchange Resins for the Extraction of Perfluorinated Chemicals
EPA Grant Number: SU839454Title: Synthesis and Characterization of Fluorinated Hydrocarbon Anion Exchange Resins for the Extraction of Perfluorinated Chemicals
Investigators: Danielson, Neil , Berberich, Jason , Almquist, Catherine B , Smith, Abby , Wourms, Hannah , Beckman, Matthew , Kuehl, Emily , Spilker, Robert
Institution: Miami University - Oxford
EPA Project Officer: Page, Angela
Phase: I
Project Period: December 1, 2018 through November 30, 2019 (Extended to November 30, 2021)
Project Amount: $14,999
RFA: P3 Awards: A National Student Design Competition Focusing on People, Prosperity and the Planet (2018) RFA Text | Recipients Lists
Research Category: P3 Awards , P3 Challenge Area - Safe and Sustainable Water Resources
Objective:
To the best of our knowledge, the application of any completely polymeric mixed mode fluorocarbon substituent/anion exchange material for the adsorption of perfluoroalkyl chemicals (PFCs) has never been reported. We proposed an approach to prepare a pH and pressure stable mixed mode fluorocarbon substituent/anion exchange material for the adsorption of PFCs such as perfluorooctanoic acid (PFOA). Toward this goal, the broad tasks of this research are to: 1) Synthesize and characterize a Kel-F 800/weak anion exchange resin, 2) Compare the adsorption capacity and thermodynamic parameters of the adsorbents for PFOA in the batch mode and the adsorption kinetics of the adsorbents for PFOA in the column breakthrough mode, 3) Investigate how representative co-contaminants and minerals in the water impact adsorption capacity and adsorption kinetics of the PFCs, and 4) Demonstrate that the adsorbents can be regenerated and reused.
Summary/Accomplishments (Outputs/Outcomes):
We have pioneered the use of mixed mode fluorocarbon polymer/aminopropyl silica as column packings for high performance liquid chromatography (HPLC) based on polychlorotrifluoroethylene-vinylidene fluoride co-polymer (Kel-F 800) modified aminopropyl silica. In this work, we have used a controlled particle and pore size polystyrene-divinylbenzene weak anion exchange (PSDVB-WAX) polymer as the basis for a completely new class of pH and pressure stable fluorocarbon polymer/anion exchange polymer hybrid materials for the adsorption of perfluorochemicals (PFCs) such as perfluorooctanoic acid (PFOA). This fluorous affinity between adsorbent and PFCs should provide enhanced selectivity as well as good adsorption capacity.
This study developed a dual grafted fluorinated hydrocarbon amine weak anion exchange (WAX) polymeric resin (Sepra-WAX-KelF-PEI) for PFOA removal from water. This polymer was synthesized by a two-step amine grafting reaction procedure involving first the reaction of the Sepra-WAX hydrocarbon polymer with poly(vinylidinefluoride-chlorotrifluoroethylene) (Kel-F 800) and then a second reaction with polyethyleneimine (PEI). Characterization of the synthesized polymers was performed using scanning electron microscopy and elemental analysis (F and Cl) by energy dispersive X-ray spectroscopy. The PFOA adsorption performance evaluations were conducted by packed column flow analyses with on-line detection. We have shown that the PSDVB-WAX-Kel-F-PEI particles can be packed into stainless steel liquid chromatography (LC) columns of 0.4 cm ID and 2 cm in length using simple glass wool plugs as frits. The adsorption performance of these columns has been investigated using standard LC instrument hardware composed of a high pressure pump and a
UV-VIS detector with on-line data acquisition software. A solution of PFOA was pumped through the polymer packed column in order to generate a breakthrough curve. The results show the breakthrough of the Sepra-WAX-KelF-PEI synthesized with optimum stoichiometry was two times better than the starting anion exchange polymer Sepra-WAX, and six times better than powdered activated carbon, when using the same column size.
The adsorption mechanisms of this novel adsorbent including hydrophobic interaction and electrostatic interaction were also clarified in this study. The adsorption kinetic parameters of the two optimum synthesized sorbents were determined using the Thomas model, the Yoon-Nelson model, and batch isotherm studies, and compared with those found with activated carbon and the starting WAX resin. Good agreement of the batch isotherm and column studies with respect to adsorption capacities trends between all three polymers (Sepra-WAX, Sepra-WAX-KelF, and Sepra-WAX-KelF-PEI) were noted. Regeneration of the PSDVB-WAX-Kel-F-PEI packed column after PFOA adsorption was possible using a mixture of 10% 0.05 M methanesulfonic acid and 90% acetonitrile solution as the desorption solution to remove the retained PFOA through both ion exchange and hydrophobic forces without damaging the polymer. The PFOA adsorption efficiency can be maintained for at least five cycles without any reduction.
Conclusions:
We have shown definitely that this dual grafted fluorinated hydrocarbon amine weak anion exchange resin polymer (PSDVB-WAX-Kel-F-PEI) is effective for the adsorption of PFOA from water and has excellent potential for solid phase extraction analytical applications. The potential for amine activated carbon particles to be modified in an analogous way for preparative adsorption columns is likely future work.
Journal Articles on this Report : 1 Displayed | Download in RIS Format
Other project views: | All 5 publications | 1 publications in selected types | All 1 journal articles |
---|
Type | Citation | ||
---|---|---|---|
|
Xie R, Zhou L, Smith AE, Almquist CB, Berberich JA, Danielson ND. A dual grafted fluorinated hydrocarbon amine weak anion exchange resin polymer for adsorption of perfluorooctanoic acid from water. Journal of Hazardous Materials 2022;431:128521. |
SU839454 (Final) |
Exit |
Supplemental Keywords:
Perfluoroalkyl chemicals (PFCs), perfluorooctanoic acid (PFOA), water treatment, polystyrene-divinylbenzene (PSDVB), weak anion exchange (WAX), Kel-F 800, polyethyleneimine (PEI).Progress and Final Reports:
Original AbstractThe 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.