Thixotropic gel for vadose zone remediation
AssigneeSavannah River Nuclear Solutions, LLC
InventorsBrian D. Riha, Brian B. Looney
Life of this patent
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Abstract
A thixotropic gel suitable for use in subsurface bioremediation is provided along with a process of using the gel. The thixotropic gel provides a non-migrating injectable substrate that can provide below ground barrier properties. In addition, the gel components provide for a favorable environment in which certain contaminants are preferentially sequestered in the gel and subsequently remediated by either indigenous or introduced microorganisms.
Claims15
A process of bioremediation within one of a vadose zone;
- a saturated zone or capillary fringe zone comprising:
- identifying a contaminant area;
- creating a thixotropic injectable solution comprising a mixture of an edible oil, water, and fumed silica;
- agitating said thixotropic injectable solution, thereby enabling said thixotropic injectable solution to be injected under pressure to at least one a vadose zone, a saturated zone or a capillary fringe zone;
- injecting said thixotropic solution into at least one of the vadose zone, the saturated zone or the capillary fringe zone, the injectable solution thereby forming a non-migrating gel within the at least one of the vadose zone, the saturated zone or the capillary fringe zone;
- wherein said non-migrating gel establishes an in situ anaerobic environment in response to biological colonization within said non-migrating gel.
A process of remediating volatile organic compounds within a below ground contaminant area comprising:
- injecting a thixotropic material into a contaminant area contaminated with volatile organic compounds, said thixotropic material comprising an oil selected from the group consisting of soy bean oil, mineral oil, and combinations thereof;
- sequestering within said oil said volatile organic compounds present within the contaminant area;
- establishing anaerobic conditions within said thixotropic material;
- and,
- degrading said volatile organic compounds by the metabolic activity of bacteria present within said thixotropic material.
A process of remediating heavy metals from subsurface soils comprising:
- injecting a thixotropic material into a subsurface region contaminated with heavy metals, said thixotropic material comprising an oil selected from the group consisting of soy bean oil, mineral oil, and combinations thereof;
- sequestering within said thixotropic material heavy metals from said surrounding soil;
- and,
- establishing conditions within said thixotropic material in proximity to said sequestered heavy metals wherein said heavy metals are treated by at least one of a treatment step selected from the group consisting of chelating said heavy metal, metabolizing said heavy metal, oxidizing said heavy metal, reducing said heavy metal, binding said heavy metal to a non-migratory substrate, and combinations thereof.
A process of bioremediation of a dense non-aqueous phase liquid (DNAPL) pool within a subsurface of a soil comprising:
- identifying a contaminant area having a DNAPL pool;
- creating a thixotropic injectable solution comprising a mixture of an edible oil, water, and fumed silica;
- agitating said thixotropic injectable solution, thereby enabling said thixotropic injectable solution to be injected under pressure to the contaminant area;
- injecting said thixotropic solution into the contaminant area, the injectable solution thereby forming a non-migrating gel which encapsulates the DNAPL pool;
- and,
- bioremediating the DNAPL pool by the biological activity of organisms within the thixotropic solution.
Dependencies are inferred from the claim text.