Journal article
Functionalized electrospun polymer nanofibers for treatment of water contaminated with uranium
Environmental science water research & technology, Vol.6(3), pp.622-634
03/05/2020
DOI: 10.1039/C9EW00834A
Abstract
Uranium (U) contamination of drinking water often affects communities with limited resources, presenting unique technology challenges for U6+ treatment. Here, we develop a suite of chemically functionalized polymer (polyacrylonitrile; PAN) nanofibers for low pressure reactive filtration applications for U6+ removal. Binding agents with either nitrogen-containing or phosphorous-based (e.g., phosphonic acid) functionalities were blended (at 1–3 wt%) into PAN sol gels used for electrospinning, yielding functionalized nanofiber mats. For comparison, we also functionalized PAN nanofibers with amidoxime (AO) moieties, a group well-recognized for its specificity in U6+ uptake. For optimal N-based (Aliquat® 336 or Aq) and P-containing [hexadecylphosphonic acid (HPDA) and bis(2-ethylhexyl)phosphate (HDEHP)] binding agents, we then explored their use for U6+ removal across a range of pH values (pH 2–7), U6+ concentrations (up to 10 μM), and in flow through systems simulating point of use (POU) water treatment. As expected from the use of quaternary ammonium groups in ion exchange, Aq-containing materials appear to sequester U6+ by electrostatic interactions; while uptake by these materials is limited, it is greatest at circumneutral pH where positively charged N groups bind negatively charged U6+ complexes. In contrast, HDPA and HDEHP perform best at acidic pH representative of mine drainage, where surface complexation of the uranyl cation likely drives uptake. Complexation by AO exhibited the best performance across all pH values, although U6+ uptake via surface precipitation may also occur near circumneutral pH values and at high (10 μM) dissolved U6+ concentrations. In simulated POU treatment studies using a dead-end filtration system, we observed U removal in AO-PAN systems that is insensitive to common co-solutes in groundwater (e.g., hardness and alkalinity). While more research is needed, our results suggest that only 80 g (about 0.2 lbs.) of AO-PAN filter material would be needed to treat an individual's water supply (contaminated at ten-times the U.S. EPA maximum contaminant level for U) for one year.
Details
- Title: Subtitle
- Functionalized electrospun polymer nanofibers for treatment of water contaminated with uranium
- Creators
- Adam Johns - Department of Civil and Environmental Engineering, University of Iowa, Iowa City, USAJiajie Qian - Department of Civil and Environmental Engineering, University of Iowa, Iowa City, USAMargaret E Carolan - Department of Civil and Environmental Engineering, University of Iowa, Iowa City, USANabil Shaikh - Department of Civil, Construction & Environmental Engineering, University of New Mexico, Albuquerque, USAAllison Peroutka - Department of Chemical and Biochemical Engineering, University of Iowa, Iowa City, USAAnna Seeger - Department of Civil and Environmental Engineering, University of Iowa, Iowa City, USAJosé M Cerrato - Department of Civil, Construction & Environmental Engineering, University of New Mexico, Albuquerque, USATori Z Forbes - Department of Chemistry, University of Iowa, Iowa City, USADavid M Cwiertny - Department of Civil and Environmental Engineering, University of Iowa, Iowa City, USA, Department of Chemical and Biochemical Engineering
- Resource Type
- Journal article
- Publication Details
- Environmental science water research & technology, Vol.6(3), pp.622-634
- DOI
- 10.1039/C9EW00834A
- ISSN
- 2053-1400
- eISSN
- 2053-1419
- Grant note
- DOI: 10.13039/100000066, name: National Institute of Environmental Health Sciences, award: R01ES027145; DOI: 10.13039/100000001, name: National Science Foundation, award: DGE-1633098
- Language
- English
- Date published
- 03/05/2020
- Academic Unit
- Center for Health Effects of Environmental Contamination; Civil and Environmental Engineering; Core Research Facilities; IIHR--Hydroscience and Engineering; Public Policy Center (Archive); Chemistry; Chemical and Biochemical Engineering
- Record Identifier
- 9984066115302771
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