Research and Demonstration of Electrospun Nanofiber Filters: Multifunctional, Chemically Active Filtration Technologies for Small-Scale Water Treatment SystemsEPA 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: Page, Angela
Project Period: December 1, 2011 through November 30, 2016
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
This research and demonstration plan will fabricate multi-layered nanofiber mats via electrospinning and optimize their performance as chemically active filtration technologies. This work will optimize the reactivity of (i) maganagese-doped titanium dioxide (Mn-TiO2) nanofibers for use as visible-light photocatalysts, (ii) aluminum-doped iorn oxide (Al-Fe2O3) nanofibers as heavy metal sorbents, and (iii) carbon nanofibers as sorbents for organic microsconstituents. Once optimized, these highly reactive building blocks will be integrated into a single filter unit with sequential yet spatially resolved layers of each nanomaterial, imparting true multi-functionality and the ability to perform several treatment operations simultaneously over small spatial scales. We hypothesize that nanofibers will exhibit superior activity relative to traditional reactive media: the ability to tune nanofiber properties during electrospinning enables optimization of their reactivity (e.g., surface area) and sustainability (e.g., tailoring Mn levels in TiO2 to enhance visible light photoactivity). Demonstration objectives will highlight the synergistic performance characteristics of Mn-TiO2lAI-Fe20l/carbon nanofiber mats when applied to source waters representative of rural systems (e.g. contaminated by arsenic, agrochemicals and pharmaceuticals).
Mn-Ti02, AI-Fe2O3, and carbon nanofibers with systematically varied properties (e.g. diameter, crystal phase, dopant-levels) will be synthesized via electrospinning and extensively characterized (Task 1). Characterization data will then be coupled with results from batch reactivity studies (Task 2) to identify the nanofiber properties most critical for optimal treatment efficiencies. Using the most reactive nanofiber formulations as building blocks, we will then synthesize and evaluate the performance of a multi-component nanofiber filter consisting of sequential layers of Mn-Ti02, AI-Fe2O3 and carbon. This filter will be tested in multiple application platforms, including as a point-or-use. in-home gravity flow filter (Task 3) and via integration as reactive coatings on ceramic microfiltration membranes (Task 4) for larger treatment volumes.
This work will provide the production framework for next-generation treatment technologies capable of targeting diverse chemical pollutants over a range of water chemistries and application scales. Tangible outcomes include a wealth of demonstration data and standard operating procedures that will help better inform communities deciding whether technology adoption is appropriate for their water supply. This work will also spur growth in applications of electrospun nanofibers, an innovative class of nanomaterials yet to be fully integrated into water treatment. Regional partnerships with three water suppliers in Iowa provide a unique pathway toward the continued development of nanofiber filter technologies.