In situ soil decontamination method and apparatus

摘要

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.