The remediation of toxic metals from water with high concentrations of salt has been an emerging area for membrane separation. Cost-effective nanomaterials such as iron and iron oxide nanoparticles have been widely used in reductive and oxidative degradation of toxic organics. Similar procedures can be used for redox transformations of metal species (e.g. metal oxyanions to elemental metal), and/or adsorption of species on iron oxide surface. In this study, iron-functionalized membranes were developed for reduction and adsorption of selenium from coal-fired power plant scrubber water. Iron-functionalized membranes have advantages over iron suspension as the membrane prevents particle aggregation and dissolution. Both lab-scale and full-scale membranes were prepared first by coating polyvinylidene fluoride (PVDF) membranes with polyacrylic acid (PAA), followed by ion exchange of ferrous ions and subsequent reduction to zero-valent iron nanoparticles. Water permeability of membranes decreased as the percent PAA functionalization increased, and the highest ion exchange capacity (IEC) was obtained at 20% PAA with highly pH responsive pores. Although high concentrations of sulfate and chloride in scrubber water decreased the reaction rate of selenium reduction, this was shown to be overcome by integration of nanofiltration (NF) and iron-functionalized membranes, and selenium concentration below 10. μg/L was achieved.
|Number of pages||13|
|Journal||Journal of Membrane Science|
|State||Published - Aug 5 2015|
Bibliographical noteFunding Information:
This project has been supported by Southern Company in Birmingham, AL, National Institute of Environmental Health Sciences Superfund Research Program of the National Institutes of Health (NIH-NIEHS-SRP) under Award no. P42ES007380 , and by National Science Foundation Kentucky EPSCoR program (NSF Award no. 1355438 ). The content is solely the responsibility of the authors and does not necessarily represent the official views of NIH. XPS analysis was supported by NSF under Grant no. 0814194 . We thank the significant contributions of Nanostone/Sepro Membranes, Inc. in Oceanside, CA for joint development of full-scale functionalized membranes. Joseph Papp was also supported by the NSF REU program. We also thank Mr. Xinjun Teng (formerly of Southern Company Services, Inc.) for his role in initiating and managing Southern׳s contribution to this project in the early stages.
© 2015 Elsevier B.V.
- Nanocomposite membrane
- Surface modification
ASJC Scopus subject areas
- Materials Science (all)
- Physical and Theoretical Chemistry
- Filtration and Separation