Method and apparatus for hydrocarbon-contaminated soil remediation

摘要

A method and apparatus for ex situ remediation of hydrocarbon- contaminated soil, comprising the excavation of the soil from its in situ position and forming a covered pile of loosened soil, at the base of which an array of a plurality of hot air inlet conduits are located. At least one array of a plurality of gas take-off conduits are situated at one or more higher level(s) in the pile. Heated air is injected into the inlet conduits at the base of the pile and allowed to percolate up through the soil to remove the hydrocarbons and volatile organic compounds as hydrocarbon vapor entrained process gas. This process gas is drawn off by applying a negative pressure to the take-off conduits. The drawn-off process gases are then passed through a gas burner which thermally oxidizes the hydrocarbons and organic compounds. The heat generated from the gas burner is exchanged with ambient inlet air to provide the hot air used to inject into the base soil pile. Several layers of inlet and/or exhaust conduit arrays may be provided. The oxygen content and temperature of the exhaust gas is measured downstream of the burner. Auxiliary air is supplied to the burner when the O.sub.2 content drops below about 12% and the auxiliary fuel supplied when the temperature falls below about 1400° F. The covering traps heat and prevents air dilution.