Thermal blanket
A thermal blanket is a device used in thermal desorption to clean soil contamination. The primary function of a thermal blanket is to heat the soil to the boiling point of the contaminants (usually 100 to 325°C). The contaminants break down. A vacuum pulls the resulting gas (along with some contaminants) into a separate air cleaner that may use various methods, such as carbon filters and high-heat ovens, to completely destroy the contaminants.
Deep contamination is handled using a similar method with a deep penetrating heat source. This is commonly referred to as an In Situ Thermal Desorption (ISTD) thermal well.
Concerns
There is a concern that as a contaminant becomes heated, it may leak outside of the area of the thermal blanket. Therefore, the blanket must completely cover the contaminated area and have a strong enough vacuum to prohibit the spread of contaminations.
Incomplete destruction of contaminants may lead to the introduction of dioxins and furans into the air.
This method has not been effectively tested on organic contaminants.
See also
References
- I. E. T. Iben, W. A. Edelstein, R. B. Sheldon, A. P. Shapiro, E. E. Uzgiris, C. R. Scatena, S. R. Blaha, W. B. Silverstein, G. R. Brown, G. L. Stegemeier, and H. J. Vinegar (1985). "Thermal Blanket for In-Situ Remediation of Surficial Contamination: A Pilot Test". Environ. Sci. Technol. 30 (11): 3144–3154. doi:10.1021/es9506622.