Method of in situ soil remediation for volatile organic contaminants

A method of in-situ soil remediation with a chemical oxidizing agent to reduce the concentration level of a volatile organic contaminant to a target concentration level, comprising the sequential steps of:

• a) treating the contaminated soil in-situ by a thermal-stripping process in which the soil is churned by a soil mixing device and hot air is injected into the soil as it is being churned to thermally strip off organic compounds, including the volatile organic contaminant, the thermal-stripping process being continued until such thermal stripping is no longer practically effective in further reducing the contaminant level of the volatile organic contaminant;
• b) determining the concentration level of the volatile organic contaminant remaining after the thermal stripping process;
• and
• c) further reducing the concentration of the volatile organic contaminant by introducing a chemical oxidizing agent into the soil in an amount that is effective over reasonable time to reduce the concentration level to or below the target level.

A method of soil remediation to reduce the concentration level of a contaminant organic compound in soil to a target concentration level, comprising, in sequence, the steps of:

• a) churning the soil with a soil mixing device;
• b) during churning, injecting hot air into the soil to thermally strip off organic compounds, including natural and benign organic compounds, to reduce the contaminant concentration level to a decreased level that is still above the target level, the step of injecting hot air into the soil being continued until such thermal stripping is no longer practically effective in further reducing the contaminant concentration level;
• and
• c) introducing a chemical oxidizing agent into the soil in an amount that is effective over reasonable time to further reduce the concentration level of the thermally stripped contaminant to or below the target level.

A method in-situ soil remediation to reduce the concentration level of a contaminant organic compound in soil to a target concentration level, comprising, in sequence, the steps of:

• a) comminuting the soil in situ with a trenching tool;
• b) during comminution, injecting hot air into the soil to thermally strip off organic compounds, including natural and benign organic compounds, the step of injecting hot air being continued until thermal stripping is no longer practically effective in further reducing the contaminant concentration level;
• and
• c) introducing a chemical oxidizing agent into the soil in an amount that is effective over reasonable time to reduce the contaminant concentration level to or below the target level.