US EPA

Membrane-Based Nanostructured Metals for Reductive Degradation of Hazardous Organics at Room Temperature

EPA Grant Number: R829621
Title: Membrane-Based Nanostructured Metals for Reductive Degradation of Hazardous Organics at Room Temperature
Investigators: Bhattacharyya, Dibakar , Bachas, Leonidas G. , Ritchie, Stephen M.C.
Current Investigators: Bhattacharyya, Dibakar , Bachas, Leonidas G. , Lewis, Scott , Meyer, David , Ritchie, Stephen M.C. , Tee, Y.
Institution: University of Kentucky , University of Alabama - Tuscaloosa
EPA Project Officer: Savage, Nora
Project Period: January 1, 2002 through December 31, 2004 (Extended to March 31, 2006)
Project Amount: $345,000
RFA: Exploratory Research: Nanotechnology (2001) RFA Text |  Recipients Lists
Research Category: Hazardous Waste/Remediation , Nanotechnology , Safer Chemicals

Description:

The overall objective of this proposal is the development and fundamental understanding of reductive dechlorination of selected classes of hazardous organics by immobilized nanosized metal particles (single and bimetallic systems) in ordered membrane domains. This integrated research will examine nanoparticle synthesis in a membrane domain, the role of metal surface area and surface sites, the potential role of ordered nanometal domains in membranes, membrane partitioning and reaction kinetics with the main emphasis on obtaining highly enhanced dechlorination rates, and selectivity from dilute aqueous solutions. The overall hypothesis to be tested is that nanosized (< 50 nm) zero-valent metal domains can be created in an ordered membrane matrix by the use of novel, polypeptide-based biomolecules with helix-coil forming ability or by di-block copolymers. The Specific Objectives of our studies are hypothesis based and will lead to greater insight into hazardous organics dechlorination by providing a highly flexible membrane platform containing nanosized metals. Some of the main hypotheses to be tested include: use of polyfunctional metal binding ligands (such as, polyamino acids [PAA]) will lead to high loadings of nanosized reactive metals in ordered membrane domains; PAA's proven helix-forming ability will lead to ordered zero-valent metal entrapment for potential dechlorination selectivity; dissolved metals (a consequence of dechlorination reactions) can be recaptured in these membranes and thus reused; use of block copolymers will lead to the development of very small size and mono-disperse nanoparticles; membrane partitioning of chlorinated organics will lead to high reaction rates and selectivity.

Approach:

In this work we propose to examine immobilized nanostructured metals for dechlorination of hazardous organics. The uniqueness of our project is that, in contrast to literature reported data, membrane partitioning and in-situ synthesis of nanoparticles in a membrane phase will provide highly enhanced dechlorination rates (200 to 1000-fold) and selectivity. This project will establish the role of selected nanoscale particles (Fe, Zn, Pd, selected bimetallic systems) in membrane platforms, the rate of dehalogenation reactions, establish selectivity for the formation of particular rate-controlling intermediates, and determine the effects of nanoparticle surface area/chemistry and membrane partitioning. Significant efforts will be placed on the degradation of TCE to its intermediates, as well as the degradation of selected chlorinated aromatics. The specific organic degradation studies in dilute solutions will include: TCE and intermediates such as, cis-and trans-DCE (with Fe and Zn), mono-/di- chlorophenol (bimetallic systems), and 1,2 dichloro- and 1,2,4 trichloro- benzenes (M0 - Pd nanoparticles). The reductive dechlorination results (in metal particle dispersed solution phase) of some of these compounds are available, and thus direct quantitative comparisons of our membrane based nanometal systems would be possible.

Expected Results:

The development of the proposed membrane-based nanostructured metals synthesis for reductive dechlorination of various hazardous organics will provide a novel technique for the rapid and selective degradation of hazardous organics at room temperature. The development of this technology will have a significant impact on the role of nanostructured materials in the environmental field for current and future needs. The fundamentally new technique for creating environmentally-applicable nanoparticles in an ordered fashion by immobilization in a membrane matrix provides a versatile platform to address diverse needs in both industrial manufacturing and remediation. Kinetic modeling and correlations with molecular descriptors should establish an excellent foundation for fundamental understanding of nanotechnology-based reaction systems. The additional benefits of this work will lead to reduction of materials usage and miniaturization of dechlorination reactor systems by more efficient use of metals and selectivity.

Publications and Presentations:

Publications have been submitted on this project: View all 34 publications for this project

Journal Articles:

Journal Articles have been submitted on this project: View all 6 journal articles for this project

Supplemental Keywords:

engineering, environmental chemistry, innovative technology, sustainability, recycle, toxics, VOC., RFA, Scientific Discipline, Toxics, Sustainable Industry/Business, Environmental Chemistry, Sustainable Environment, VOCs, Technology for Sustainable Environment, Analytical Chemistry, Civil/Environmental Engineering, Biochemistry, New/Innovative technologies, Chemistry and Materials Science, Engineering, Environmental Engineering, nanotechnology, reductive degradation of hazardous organics, environmentally applicable nanoparticles, sustainability, reductive dechlorination, hazardous organics, innovative technologies, membrane-based nanostructured metals

Progress and Final Reports:

2002 Progress Report
2003 Progress Report
Final Report