Technology:
Thermal Desorption
- Thermal desorption unit was a “triple dryer”, a rotating cylindrical kiln with two concentric cylindrical chambers used to supply indirect heat at 40 million BTU/hr
- Soil was screened to remove material greater than 2 inches in diameter
- System processed an average of approximately 225 tons of soil per day, with a typical soil exit temperature of 900°F
- Off gases treated using a scrubber, venturi, and spray tower, followed by a high-efficiency particulate air (HEPA) filter, and a vapor phase carbon filter unit
- Blowdown from off-gas treatment - treated using carbon; water from the scrubber, venturi, and spray tower - treated using a clarifier and filter press
- Treated soil was backfilled on site
- Results of performance test prior to full-scale operation identified elevated levels of particulate emissions at the stack; several system modifications performed to address the issue
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Cleanup Authority:
CERCLA
Contacts:
EPA RPM:
Stephanie Vaughn
EPA Region 2
290 Broadway
New York, NY 10007
Telephone: (212) 637-3914
E-mail: vaughn.stephanie@epa.gov | Technology Provider:
Stan Wojinski
Environmental Chemical Corporation
999-18th Street, Suite 2350
Denver, CO 80202
Telephone: (303) 298-7607
E-mail: swojinski@ecc.net |
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Contaminants:
Pesticides, semivolatile organic organic compounds, and PCBs; semivolatile organic organic compounds (SVOCs) such as bis (2-ethylhexyl) phthalate (BEHP), 3,3'-dichlorobenzidene, and polyclic aromatic hydrocarbons (PAHs); and metals such as antimony and arsenic
- Highest concentrations measured were for PCB Aroclor 1260 at 4,000 mg/kg, BEHP at 280 mg/kg, and antimony at 12.6 mg/kg |
Waste Source:
Leaking drums |
Type/Quantity of Media Treated:
Soil
- 53,685 cubic yards |
Purpose/Significance of Application:
Use of thermal desorption to treat soil contaminated with a variety of organic contaminants including pesticides, SVOCs, and PAHs |
Regulatory Requirements/Cleanup Goals:
- ROD specified cleanup goals as - PCBs - 1 mg/kg; BEHP - 46 mg/kg; 3,3'-Dichlorobenzidene - 1.4 mg/kg; and arsenic - 20 mg/kg
- System operated under an air quality permit that included action levels for ambient air at site boundary locations, and a water discharge permit |
Results:
- Treated soil was placed into 250 cubic yard bins (260 stockpiles total) and one composite sample was collected from each bin and analyzed for PCBs, SVOCs, and arsenic
- Results showed that concentrations for PCBs, SVOCs, and arsenic in treated soil met the cleanup goals
- 16 of the 260 stockpiles of treated soil (approximately 6%) were retreated because they did not initially meet the cleanup goals |
Cost Factors:
- Actual costs for this application - $15,700,000, including capital and O&M costs
- Unit cost of $292 per cubic yard, based on 53,685 cubic yards of soil treated |
Description:
The 9.67 acre Industrial Latex Superfund Site, in Wallington, New Jersey was used to manufacture natural and synthetic rubber compounds and chemical adhesives from 1951 to 1983. Solvents used in the manufacturing process included volatile organic compounds (VOCs) such as acetone, heptane, hexane, methyl ethyl ketone, and methylene chloride, as well as PCBs. Leaking drums of various chemical compounds were found at the site and soil and groundwater at the site were determined to be contaminated with PCB Aroclor 1260; semivolatile organic organic compounds (SVOCs) such as bis (2-ethylhexyl) phthalate (BEHP), 3,3'-dichlorobenzidene, and polyclic aromatic hydrocarbons (PAHs); and metals such as antimony and arsenic. The site was added to the Superfund National Priorities List (NPL) in March 1989. The ROD signed in September 1999 specified thermal desorption to address contaminated soil.
From April 1999 to June 2000, thermal desorption was used to treat 53,685 cubic yards of soil. The thermal desorption unit was a “triple dryer” consisting of a rotating cylindrical kiln with two concentric cylindrical chambers. The unit used indirect heat at 40 million BTU/hr. Thermal treatment achieved the cleanup goals for PCBs, BEHP, 3,3'-dichlorobenzidene, and arsenic. Over the course of the cleanup, 16 of the 260 stockpiles of treated soil (approximately 6%) were retreated because they did not initially meet the cleanup goals. During the performance test, elevated levels of particulate emissions were identified and the HEPA filter housing was modified, with particulate emissions reduced to within permitted levels. |
