Technology:
In Situ Vitrification (ISV)
- Patented process that destroys organics and some inorganics by pyrolysis
- Uses electricity as energy source
- Remaining contaminants (heavy metals and radionuclides) are incorporated into product; product has significantly reduced leachability
- Vitrified material has 20-50% less volume than original material
- Hood used to contain and collect off-gasses from melt
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Cleanup Authority:
- Information not provided about authorities for specific remediations and demonstrations
- Detailed regulatory analysis of ISV provided by CERCLA criteria
SIC Code:
9711 (National Security)
Commercial sites - Information not provided
Others - Information not provided | Point of Contact:
J. Hansen, Geosafe, (509) 375-0710
Jim Wright, DOE, (803) 725-5608
B. Spalding, ORNL, (423) 574-7265 |
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Contaminants:
Parsons: pesticides (chlordane, dieldrin, 4,4-DDT), metals (As, Pb, Hg)
ORNL: Radioactive elements (Ce137)
Wasatch: dioxin/furan, pentachlorophenol, pesticides, VOCs, SVOCs
Private Superfund site: PCBs |
Waste Source:
Wasatch - Other (concrete evaporation pond)
Others - Information not provided |
Type/Quantity of Media Treated:
Soil, Sludge, and Debris
- Parsons: 4800 tons
- Wasatch: 5600 tons
- Private Superfund site: 3100 tons |
Purpose/Significance of Application:
Full-scale and field demonstrations of ISV for variety of media types and variety of contaminants |
Regulatory Requirements/Cleanup Goals:
- Parsons: regulatory limits for Hg, chlordane, dieldrin, and 4,4-DDT
- Others - information not provided |
Results:
- Parsons: contamination reduced to below detection limits (ND) for most constituents
- Wasatch: molten product dip samples and surrounding berm post-ISV samples mostly ND
- ORNL treatability test had a "melt expulsion event (MEE)" where excess water vapor generation upset the melt and caused overheating of the off-gas collection hood
- Superfund site in Washington State showed DRE for PCBs of greater than 99.9999% |
Cost Factors:
- Vitrification operations $375-425/ton
- Ancillary costs: treatability/pilot testing - $50-150K; mobilization - $150-200K; and demobilization - $150-200K
- No information is provided on the capital or operating costs for specific full-scale or demonstration projects |
Description:
In situ vitrification (ISV) has been used in three large-scale commercial remediations in the United States and in several demonstrations. The commercial remediations were conducted at the Parsons Chemical Superfund site (see separate report on Parsons); a Superfund site in Washington State; and at the Wasatch Chemical site. A demonstration of ISV was conducted at ORNL WAG 7 on Ce137-contaminated material, where a melt expulsion event occurred .
ISV simultaneously treats mixtures of waste types, contaminated with organic and inorganic compounds. ISV has been demonstrated at sites contaminated with hazardous and mixed wastes, and achieves volume reductions ranging from 20-50%. Metals and radioactive elements are bound tightly within the vitrified product. Full-scale remediation at Parsons met the regulatory limits for chlordane, dieldrin, 4,4-DDT, and mercury. Full-scale remediation at Wasatch achieved ND for 12 constituents in the molten product dip samples. A TSCA demonstration at a Superfund site in Washington State showed destruction and removal efficiency (DRE) for PCBs of greater than 99.9999%. At the ORNL WAG 7 demonstration, a need was identified to take additional precautions when dealing with sites containing large amounts of free water.
Site requirements for ISV, as identified by the vendor, are a function of: (1) the size and layout for equipment used in the process; (2) the staging area requirements for treatment cell construction; and (3) the area needed for maneuvering and operating equipment, excavating soils, and preparing treatment cells. In addition, the properties for fusion, melt temperature, and viscosity are determined by the overall oxide composition of the soil. |
