Grantee Research Project Results
2003 Progress Report: Membrane-Based Nanostructured Metals for Reductive Degradation of Hazardous Organics at Room Temperature
EPA Grant Number: R829621Title: Membrane-Based Nanostructured Metals for Reductive Degradation of Hazardous Organics at Room Temperature
Investigators: Bhattacharyya, Dibakar , Bachas, Leonidas G. , Ritchie, Stephen M.C. , Hollman, Aaron , Claiborn, Cherqueta , Meyer, David , Xu, Jian , Wu, Linfeng , Campbell, Morgan , Ashcraft, Nathan
Current Investigators: Bhattacharyya, Dibakar , Bachas, Leonidas G. , Ritchie, Stephen M.C. , Meyer, David , Lewis, Scott , Tee, Y.
Institution: University of Kentucky , The University of Alabama
EPA Project Officer: Hahn, Intaek
Project Period: January 1, 2002 through December 31, 2004 (Extended to March 31, 2006)
Project Period Covered by this Report: January 1, 2003 through December 31, 2004
Project Amount: $345,000
RFA: Exploratory Research: Nanotechnology (2001) RFA Text | Recipients Lists
Research Category: Hazardous Waste/Remediation , Nanotechnology , Safer Chemicals
Objective:
The overall objective of this research project is the development and fundamental understanding of reductive dechlorination of selected classes of hazardous organics by immobilized nanosized metal particles in polymeric membrane systems. This integrated research involves nanoparticle synthesis in various membrane platforms, examining the role of metal surface area and surface sites and the potential role of ordered nanodomain in membranes for separation and reaction, and membrane partitioning/reaction kinetics. The additional benefits of this work include significant reduction of materials usage and miniaturization of dechlorination reactor systems by more efficient use of metals and increased selectivity.
Progress Summary:
Year 2 of the project has focused on understanding dechlorination using both iron and bimetallic iron/nickel nanosystems immobilized within a membrane domain. Three separate synthesis strategies have been developed and refined: (1) direct membrane-phase particle formation through modification of classic phase-inversion membrane preparation; (2) use of metal chelating polymers (such as polyacrylic acid) on membrane supports; and (3) external nanoparticle synthesis in solution followed by membrane incorporation. New areas of research in particle synthesis have focused on understanding the formation of bimetallic systems. Specifically, much attention has been given to determining the bimetallic distribution and ratio (iron [Fe] to nickel [Ni]) that result in optimal system performance and understanding why these factors have such impacts on dechlorination kinetics. To date, we have successfully demonstrated:
• Formation of nanoscale particles in the 20-30 nm range directly in cellulose acetate membranes;
• Cross-linking of polyacids on membrane supports for entrapment of metals and formation (after reduction) of metal particles approximately 30 nm;
• The ability to synthesize immobilized Fe/Ni nanoparticles with a more uniform elemental distribution for superior dechlorination performance using a two-step deposition process (reduction of Fe followed by deposition and reduction of Ni) as opposed to the simultaneous reduction of Fe and Ni;
• Large conversions for trichloroethylene (TCE) in 60 minutes using a very small quantity of bimetallic (Fe/Ni ratio 4:1) nanoparticles;
• Production of ethane (identified in the headspace) with only trace levels (if any) of other chlorinated intermediate byproducts typically found in both the aqueous and headspace phases;
• Development of a novel method for preparation of Fe0 nanoparticles and recovery as a stable slurry using anaerobic synthesis conditions;
• Immobilization of Fe0 nanoparticles prepared in solution within a cellulose acetate matrix (as one example) while avoiding metal oxidation;
• Rapid removal of a single chlorine atom from adsorbed TCE by immobilized Fe0 nanoparticles (synthesized ex situ) followed by an apparently slower degradation of the formed dichloroethylene (most likely attributed to larger particle sizes after agglomeration); and
• Enhanced reduction rates (vs. pure Fe) for TCE destruction by Ni/Fe nanoparticles formed in solution and immobilized in cellulose acetate. Preliminary results with membrane-immobilized Fe/Pd nanoparticles showed highly effective dechlorination of selected aromatics.
Future Activities:
We will optimize nanoparticle synthesis techniques in membranes that will result in highly enhanced rates of toxic organic dechlorination with minimum metal usage. Some of these activities will include: (1) identification of the kinetic mechanisms associated with the reduction of TCE by bimetallic (Fe/M) systems, which includes examining the role of Fe, M (i.e., M = Pd, Cu, etc.); and H2O in the reaction; (2) extension of Fe/M systems to other classes of halogenated pollutants (aromatics, biphenyls) through the use of metals other than Ni; (3) variation of polymeric materials to determine the effects of organic partitioning on reaction rates; (4) use of convective flow to improve particle surface accessibility with shorter residence times; and (5) use of x-ray photoelectron spectroscopy studies for polymer/nanoparticle matrices to characterize bimetallic particle formation and the presence of oxide films before and after dechlorination studies.
Journal Articles on this Report : 3 Displayed | Download in RIS Format
Other project views: | All 34 publications | 8 publications in selected types | All 6 journal articles |
---|
Type | Citation | ||
---|---|---|---|
|
Hollman AM, Scherrer NT, Cammers-Goodwin A, Bhattacharyya D. Separation of dilute electrolytes in poly(amino acid) functionalized microporous membranes: model evaluation and experimental results. Journal of Membrane Science 2004;239(1):65-79 |
R829621 (2002) R829621 (2003) R829621 (Final) |
not available |
|
Meyer DE, Wood K, Bachas LG, Bhattacharyya D. Degradation of chlorinated organics by membrane-immobilized nanosized metals. Environmental Progress 2004;23(3):232-242 |
R829621 (2003) R829621 (Final) |
not available |
|
Xu J, Dozier A, Bhattacharyya D. Synthesis of nanoscale bimetallic particles in polyelectrolyte membrane matrix for reductive transformation of halogenated organic compounds. Journal of Nanoparticle Research 2005;7(4-5):449-467. |
R829621 (2003) R829621 (Final) |
not available |
Supplemental Keywords:
phase inversion, metal chelation, cellulose acetate, polyacrylics, bimetallic, anaerobic synthesis, iron, Fe, nickel, Ni, trichloroethylene, TCE, palladium, Pd, membrane-based nanostructured metals, nanotechnology, reductive dechlorination., RFA, Scientific Discipline, Toxics, Sustainable Industry/Business, Sustainable Environment, Environmental Chemistry, VOCs, Technology for Sustainable Environment, Analytical Chemistry, Civil/Environmental Engineering, Biochemistry, New/Innovative technologies, Chemistry and Materials Science, Environmental Engineering, Engineering, nanotechnology, reductive degradation of hazardous organics, environmentally applicable nanoparticles, hazardous organics, reductive dechlorination, sustainability, innovative technologies, membrane-based nanostructured metalsProgress 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.