Remediation with thermal methods is a hot topic since steam injection, electrical conduction heating, and electrical resistance heating have been used in several successful projects. The most visible of these projects is the Visalia Superfund Project. A total of 1,300,000 pounds of wood treating chemicals were recovered there by injecting steam into an aquifer 120 feet underground. Less than one pound per day was being recovered by pump and treat. Even more robust thermal technologies are available to mineralize high concentrations of dense nonaqueous phase liquids (DNAPL) underground in a few weeks.

Using steam or temperature as high as 800°C for in situ remediation can be thought of as enhancements of soil-vapor- extraction. The primary recovery mechanism is vaporization, however, the vapor pressure of the DNAPL increases orders of magnitude, because the temperature can be far above the boiling point of water. This means that large molecules like benzo (a) pyrene and PCBs can be more mobile than benzene is in a soil-vapor-extraction project.

Moreover, oxidation or reduction to mineralize DNAPLS is much more rapid. For instance, at Visalia, the half-life of benzo (a) pyrene in heated zones is 45 days. At 600°C in an ISTD project the half-life of benzo (a) pyrene is only a few minutes. PCB's are dechlorinated by ISTD in a few minutes, and destroyed in a steam project in two months. Thus, impossible projects can now be completed in a few months to a year. Several companies are commercializing thermal technologies at a cost ranging from $25 to $200 per cubic yard for larger projects. Dozens of projects have been completed and the industry is rapidly developing.

This talk describes the case histories of steam injection, in situ thermal destruction, and electrical resistance heating projects, how the industry is developing, how simulation of thermal projects with well proven simulators is a valuable tool for optimizing important mechanisms, improving project performance and reducing cost, and how money is made by remediating property.

End_of_Record - Last_Page 17---------------