2013 Progress Report: Research and Demonstration of Electrospun Nanofiber Filters: Multifunctional, Chemically Active Filtration Technologies for Small-Scale Water Treatment Systems

EPA Grant Number: R835177
Title: Research and Demonstration of Electrospun Nanofiber Filters: Multifunctional, Chemically Active Filtration Technologies for Small-Scale Water Treatment Systems
Investigators: Cwiertny, David M. , Myung, Nosang V. , Parkin, Gene F
Institution: University of Iowa , University of California - Riverside
EPA Project Officer: Hiscock, Michael
Project Period: December 1, 2011 through November 30, 2016
Project Period Covered by this Report: December 1, 2012 through November 30,2013
Project Amount: $499,466
RFA: Research and Demonstration of Innovative Drinking Water Treatment Technologies in Small Systems (2011) RFA Text |  Recipients Lists
Research Category: Drinking Water , Water

Objective:

This research and demonstration plan aims to fabricate multi-component nanofiber mats via a novel synthesis approach, electrospinning, and optimize their performance as chemically active filtration technologies for water treatment across a range of scales and chemistries.

Progress Summary:

In Year 2, we have demonstrated our ability to successfully synthesize and tailor the performance of each type of electrospun nanofiber we originally proposed to integrate into our multi-functional reactive filtration system. For titanium dioxide (TiO2) nanofibers, which were the primary focus of efforts in Year 1, efforts in Year 2 were devoted to (i) optimizing their practical application toward persistent, emerging organic micropollutant classes and (ii) testing their performance in natural water samples collected from our project partners (the University of Iowa Water Treatment Plant). For iron oxide (hematite) sorbents, we have demonstrated our ability to synthesize nanofibers over a range of discrete diameters (from 20 nm – 200 nm), assessed their sorption capacity toward common heavy metals (e.g., copper and chromate), and compared their performance to commercially available iron oxide based sorbents. Finally, for carbon nanofibers, we have been exploring the ability of carbon nanofiber (CNF)-carbon nanotube (CNT) composites to function as high surface area sorbents for a suite of persistent organics exhibiting a range of polarities/hydrophobicities. Having successfully fabricated all of the nanofiber materials originally proposed, we remain on track to test original hypotheses and achieve all stated research objectives.

Future Activities:

Now that we have successfully fabricated TiO2, hematite and carbon nanofibers with tunable reactivities, ongoing and future work is focused entirely on improving their practical application in flow through filtration systems. Two major practical challenges must be addressed, and indeed, we are making progress. The first relates to optimizing material strength and durability so as to produce robust nanofibers suitable for application. To address this challenge, we believe composite nanofibers will offer an optimal blend of strength and performance, and thus be ideal for practical application. The other challenge relates to optimizing performance lifetime, which relates not only to their inherent reactivity but also their resistance to fouling or ability to be regenerated. As we address these practical hurdles, we expect by the end of Year 3 to be conducting flow-through experiments with single nanofiber and multilayer nanofiber filters. Finally, as noted above, we have initiated several approaches to further enhance the sustainability and reactivity of nanofiber-based filtration units. This includes exploring the use of other, novel catalytic materials (e.g., piezoelectrocatalysts), and the use of noble metal catalysts to impart unique reactivity (e.g., reduction) not originally proposed. Future efforts will continue to explore for other, innovative materials that may represent better alternatives to those materials originally proposed and thus be advantageous for also integrating into nanofiber filtration units.

Journal Articles:

No journal articles submitted with this report: View all 21 publications for this project

Supplemental Keywords:

decentralized treatment, point of use treatment, nanotechnology, water reuse, catalysis, water treatment, wastewater treatment;

Relevant Websites:

David Cwiertny | College of Engineering | The University of Iowa Exit
One Career (of many) Built by the EPA STAR Program | EPA's It All Starts with Science (Blog)
Professor Nosang V. Myung | Myung Group | University of California, Riverside Exit
Gene F. Parkin | College of Engineering | The University of Iowa Exit
Danmeng Shuai | Department of Civil & Environmental Engineering School of Engineering & Applied Science | The George Washington University Exit

Progress and Final Reports:

Original Abstract
  • 2012 Progress Report
  • 2014 Progress Report
  • 2015 Progress Report
  • Final Report