Abstracts of Remediation Case Studies, Volume 7 - Federal ...

Ex Situ Thermal Desorption using the SepraDyne TM -Raduce System at
Brookhaven National Laboratory (continued)
Description:
BNL is a DOE facility located in Upton, New York. The Laboratory conducted remedial excavation activities of the
Animal/Chemical Pits on site in 1997, generating mixed waste with elevated concentrations of mercury. A field
demonstration using the Sepradyne TM -Raduce system was conducted to evaluate the effectiveness of the system in
removing and recovering mercury from the mixed waste matrix.
The field demonstration involved treating 3,050 lbs of mixed waste consisting primarily of soil and waste carcasses. The
goals of the demonstration were to reduce total mercury concentrations in the treatment residuals to below 10 ppm, reduce
leachable mercury concentrations to below 0.025 mg/L TCLP, and reduce air emissions of mercury to below 40 µg/m3.
Analysis of the data after the demonstration was complete showed that total mercury levels ranged from 0.55 to 8 ppm,
TCLP leachable mercury levels were 0.008 mg/L or less, and air emissions of mercury averaged between 1 and 14 µg/m 3
throughout operation of the system. These data indicated that the project goals and regulatory requirements were met. The
projected unit cost for treating mercury-containing mixed waste using the Sepradyne TM -Raduce system is $0.90 per lb,
assuming a processing rate of 1,000 lb/hr and full-scale operation over a period of 10 years. This cost includes disposal
costs and excludes decontamination and decommissioning costs. Data collected during the demonstration showed that the
process was able to provide a final product with a 23% weight reduction. Based on visual inspection, the volume reduction
was estimated at approximately 40 to 50%.
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