Project 13: Bench and Field Scale Demonstration Testing of Nano-structured Bimetallic Systems for the Remediation of Dissolved Phase Contaminated Groundwater at the Paducah Gaseous Diffusion Plant, Paducah, Kentucky
PROJECT MANAGERS
Jim Kipp, Associate Director, KWRRI – University of Kentucky
Steve Hampson, Assistant Director, KRCEE – University of Kentucky
PRINCIPAL INVESTIGATORS
D. Bhattacharyya, Ph.D., University Alumni Professor, Dept. of Chemical and Materials Engineering, University of Kentucky
Dr. Lindell Ormsbee, KRCEE, University of Kentucky
BACKGROUND
The widespread use of chlorinated solvents and past disposal practices has resulted in extensive contamination of groundwater. One example is the trichloroethylene (TCE) and other inorganics (such as, TcO4-) plume in groundwater. The use of bulk zero-valent metals to decontaminate TCE has been extensively reported. The main drawbacks are: very slow reaction rates and low mobility of particles in groundwater plume. On the other hand nanostructured metal particles (particularly bimetallics, such as, Fe/Ni) provide immense benefits both in terms of highly enhanced reaction rates (TCE to non toxic ethane) without the formation of toxic intermediates (such as, vinyl chloride). Nanoscale particles that are less than 50 nm in diameter have generated extensive interest in the past few years. The reason is that the nanoscale structures can have unique physical and chemical properties that greatly differ from bulk-scale (>1 mm) materials, and in particular exhibit high mobility in groundwater plume that allows them to be injected and delivered to contaminant plumes.
The overall objective of this proposal is the development and on-site verification of reductive dechlorination technology for TCE degradation with immobilized nanosized iron particles containing trace amount of Ni or other dopants. In addition, the coating of these nanoparticles by a monolayer of hydrophobic polymer will result in enhanced partitioning of TCE on the particles and prevention of precipitate problem in groundwater. It has been shown that the incorporation of a second coating metal, such as Ni or Pd, allows for the protection of the Fe layer from oxidation with the added enhancement of catalytic activity through hydrogenation. Researchers at UK have developed a polymer-based nanoparticle synthesis technique to create particles in the 25-50 nm range. This integrated research will examine econmical nanoparticle (bimetallics) synthesis in a polymer domain, the role of metal surface area and surface sites, the potential role of polymer partitioning and reaction kinetics with the main emphasis on obtaining highly enhanced dechlorination rates. Laboratory studies have indicated highly effective dechlorination with milligram quantities of nanosized Fe metals vs. gram quantities with bulk metals. We will also perform column tests containing soil (Paducah site), and water containing TCE and other inorganics. This will allow us to establish the mobility of nanoparticles and verify their continuous degradation efficiency in soil and groundwater media. The proposed work is expected to have significant positive impact on pollution remediation through flexible and economical dechlorination technology development with high reaction rates at room temperature, significant reduction of metals usage, change in reaction pathway, and improvement in water quality. The effectiveness of the nanoparticles on the immobilization and removal of 99Tc will also be evaluated.
GOALS
TIME FRAME
Two Years
DELIVERABLES
1. Quarterly progress reports.
2. Project progress presentation at quarterly meetings.
3. Design and testing of bench-scale system deploying bimetallic nanoparticles for removal of 99Tc and TCE from contaminated PGDP groundwater.
4. Design, implementation, and testing of field-scale deployment of bimetallic nanoparticles for removal of 99Tc and TCE from contaminated PGDP groundwater.
5. Preliminary report summarizing the results of the bench scale testing
6. Final report recommending field scale demonstration with projected costs and technical considerations for full scale implementation of the technology to address remediation of groundwater contamination away from source areas at the PGDP.
TEAM MEMBERS
D. Bhattacharyya, Ph.D., University Alumni Professor, Dept. of Chemical and Materials Engineering, University of Kentucky
Dr. Lindell Ormsbee, KRCEE, University of Kentucky
Jim Kipp, Associate Director, KWRRI – University of Kentucky
Steve Hampson, Assistant Director, KRCEE – University of Kentucky
REPORTS
Toxic Organic Degradation by Immobilized Nanoparticles and Free Radical Reactions
KRCEE is a collaborative effort of Kentucky universities and is administered by the University of Kentucky.
