Abstract: A technique for in situ decontamination of an earth formation. High gas temperatures can be achieved at subsurface formations by supplying a fuel at a subsurface location, such as at the bottom of a wellbore. Pressurized air or gas preheated to a temperature of about 700.degree. F.-1200.degree. F. is supplied to the wellbore to ignite the fuel. The combustion heat produced by the fuel further heats the preheated gas to temperatures in the range of 1200.degree. F.-4500.degree., which heated gases are forced out of the borehole into the contaminated formation. Contaminants are thereby volatilized or oxidized and removed from the formation to the surface.

Abstract: A technique for decontaminating material, including disposing a grid network of perforated pipes on a base, and covering the same with contaminated soil. A barrier layer is laid on the contaminated material and provided with a vent port coupled to a vapor disposal unit via a suction system. A source of heated gas is coupled to the grid system to force heated air through the contaminated soil and vaporize the contaminants. A mobile decontamination system includes an insulated container having a top lid for loading contaminated material in the container, and an insulated back door for removing decontaminated material. Apertured pipes on the container floor convey a high temperature gas to the contaminated material to vaporize the contaminants. A suction system is coupled to a vapor outlet of the container to remove vaporized contaminants.

Abstract: Disclosed is in situ decontamination methods and apparatus for injecting a hot gas into boreholes formed in a contaminated soil area to vaporize the soil moisture and contaminants, and for collecting the vaporized contaminants at the surface of the soil. A burner heats pressurized gases and mixes the same with combustion gases for injection into the contaminated zone. A central collection system recovers the vaporized contaminants and couples such vapors to an on-site incinerator for disposal. Controlled heating of the injection gas is effective to sequentially remove different types of contaminants, as well as to provide in situ oxidation of other contaminants, while minimizing recondensation of the soil vapors. Wellbore casings are especially adapted for injecting the gas in predetermined patterns. In addition, a heater and incinerator assembly utilizes a single burner for both heating the dry gas and for incinerating the vapor contaminants.