ACS_Fa2003 WSU-TC Solid Phase Extraction (SPE)/GC-ECD Analysis for Polychlorinated Biphenyls (PCBs) in Real Liquid Hanford Nuclear Waste Samples Asopuru Okemgbo Washington State University Tri-Cities 2710 University Drive, Richland, WA 99352 American Chemical Society National Conference, September 7-11, 2003
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Asopuru Okemgbo Washington State University Tri-Cities 2710 University Drive, Richland, WA 99352
Solid Phase Extraction (SPE)/GC-ECD Analysis for Polychlorinated Biphenyls (PCBs) in Real Liquid Hanford Nuclear Waste Samples. Asopuru Okemgbo Washington State University Tri-Cities 2710 University Drive, Richland, WA 99352 American Chemical Society National Conference, September 7-11, 2003. - PowerPoint PPT Presentation
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ACS_Fa2003 WSU-TC
Solid Phase Extraction (SPE)/GC-ECD Analysis for Polychlorinated Biphenyls (PCBs) in Real Liquid Hanford Nuclear
Waste Samples
Asopuru Okemgbo
Washington State University Tri-Cities 2710 University Drive, Richland, WA 99352
American Chemical Society National Conference, September 7-11, 2003
ACS_Fa2003 WSU-TC
To evaluate sample preparation method for the determination of polychlorinated biphenyls (PCBs) in Hanford nuclear waste that would – Significantly reduce the volume of waste generated during
analysis.
– Eliminate methylene chloride as a solvent for the extraction of PCBs.
– Lower detection limit and meet regulatory requirements for PCB
– Reduce radiation exposure of analysts.
2Research Objectives
ACS_Fa2003 WSU-TC
Hanford Tank Waste
– Nuclear waste accumulated between1944 and 1987 was one of the aftermaths of World War II and Cold War nuclear bomb production.
– It is the biggest US environmental restoration, waste management, and waste treatment project.
Tank Safety, Closure Programs & River Protection Project
– Risk issues, research & resolution.
– Regulatory requirements.
– A $5.8 billion DOE Waste Treatment Project.
Hanford Site Background Information
3
ACS_Fa2003 WSU-TC
Hanford Underground Tanks 4
•149 Single Shell Tanks (SST’s)- Built 1943-1964.- Capacity of 55,000 to 1 million gal.
• 28 Double Shell Tanks (DST’s)- Built 1966-1986.- Capacity of 1.25 million gal. each.
• Contain about 54 million gal. Waste.
ACS_Fa2003 WSU-TC
5What the Tank waste looks like
Supernate Sludge
Saltcake
177 Hanford Tanks Waste Composition by Volume
Sludge
Saltcake
Supernatant
20%
34%
46%
Ref: HNF-EP-0182, Rev. 179
ACS_Fa2003 WSU-TC
6Waste Treatment Process
ACS_Fa2003 WSU-TC
Tank Safety Issues Criticality & Corrosivity Drivers
Disadvantages and Limitations• Interference problems• Uses hazardous organic solvents such as methylene chloride• Large volume of mixed radioactive waste generated • Laborious • Time consuming• High costs
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13SPE STRATEGY & CONDITIONS
SPE Sorbent: Varian’s Bond Elut, 200mg
Extractor: Positive Pressure Manifold
Sample Size: 1.0 to 10.0 mL
Spike levels: 0.01 to 500 ug/L aroclors 1016 and 1260.
Eluent: Hexane
Sample treatment: 25% sodium nitrate added to increase ionic strength for preferential sorption of PCBs
GC Conditions: EPA SW-846 Method 8082
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14Analytical Results
Evaluation SPE of 1% Synthetic Hanford Waste in 25% nitrate spiked with 40 g/L TCX, DCB, Aroclor