Projects & Sites

Permeability and Geology

Contaminant Types

CVOC

SVOC

DNAPL

Site Applications

Projects & Case Studies

Thermal Remediation of SVOCs,
PAHs and Coal Tar

TerraTherm’s proprietary In Situ Thermal Desorption (ISTD) technology has been used to complete numerous projects focused on the remediation of Semi-Volatile Organic Compounds (SVOCs) including Polychlorinated Biphenyls (PCBs) (see table below), Creosote, and Coal Tar. Project applications completed to date include PCB sites, Manufactured Gas Plant (MGP) sites, military sites, and former wood treatment facilities. Depending on the objectives, these sites can be addressed using a range of target temperatures, such as: Low temperatures (<B.P. of water, i.e., <100°C) can effectively enhance the recovery of viscous types of free product, such as coal tar. Applicable technologies: ET-DSP™ , SEE and ISTD

• Moderate temperatures (e.g., at or slightly above the B.P. of water, 100°C) can remove VOCs such as BTEX and Naphthalene from coal tar by steam distillation, which irreversibly changes the physical state of the remaining higher-boiling point Polycylic Aromatic Hydrocarbons (PAHs) from a liquid to a solid. This process, known as In Situ Thermochemical Solidification of coal tar (GTI, 2002), is very effective at halting the migration of coal tar DNAPL without excavation.
  Applicable technologies: ISTD

• Higher temperatures (e.g., 325°C) can be used to achieve destruction and extraction of SVOCs through vaporization, oxidation, and pyrolysis. Applicable SVOCs include PCBs, dioxins, PAHs, pesticides, and nitroaromatics. This approach has been proven to accomplish 95%-99% destruction of the SVOCs in situ, resulting in very low post-treatment concentrations in soil (e.g., for PCBs, <0.033 mg/kg; and for PAHs, <0.059 mg/kg of Benzo(a)pyrene toxic equivalents). Intermediate temperatures such as 200°C may be sufficient for treatment of lower-boiling SVOCs such as di- and tri-chlorobenzenes.
  Applicable technologies: ISTD

Summary: Completed ISTD Projects for PCB-Contaminated Soils