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US5656239A Expired / Lapsed US ⏱️ 0.0 years remaining

Method for recovering contaminants from soil utilizing electrical heating

Assignee: The University of Texas System
•
Filing: 1995-06-02
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Granted: 1997-08-12
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Expires: 2015-06-02
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Abstract

Abstract An in-situ method is disclosed for low pressure vaporization and recovery of contaminants from surface and near-surface soil by electrically heating the soil with a pattern of hollow electrodes and pulling a deep vacuum through the electrodes. The surface of the soil is sealed with an impermeable barrier supported by the soil. The contaminants are removed by vacuum distillation in the presence of water vapor at a temperature well below the normal boiling point of the contaminants.

Inventors

  • 👤 George Leo Stegemeier
  • 👤 Harold J. Vinegar

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-08 16:03
CPC Classifications
E; E02; E02D; E02D3/00; E02D3/11; B; B09; B09C; B09C1/00; B09C1/005; B09C1/06; B09C1/062; E02D3/02; E02D3/10; B09C2101/00

Claims Analysis

Total Claims: 32
Claim 1
Independent Claim 116 words
A method for remediation and decontamination of surface and near-surface soils comprising the steps of: implanting a pattern of hollow perforated electrodes into the soil; covering the surface of the soil with an impermeable barrier; applying a vacuum to the soil said vacuum being greater than 2 psia at the perforations in the electrodes; electrically heating the soil by conduction heating at power line frequencies through the pattern of electrodes wherein the soil is electrically heated to a temperature between 50° C. and no more than 99° C.; vaporizing contaminants in the soil at a temperature below the normal boiling point of the contaminants; and recovering the contaminants from the soil through the hollow perforated electrodes.
Claim 2
Independent Claim 116 words
A method for remediation and decontamination of surface and near-surface soils comprising the steps of: implanting a pattern of hollow perforated electrodes into the soil; covering the surface of the soil with an impermeable barrier; applying a vacuum to the soil said vacuum being greater than 2 psia at the perforations in the electrodes; electrically heating the soil by conduction heating at power line frequencies through the pattern of electrodes wherein the soil is electrically heated to a temperature between 50° C. and no more than 99° C.; vaporizing contaminants in the soil at a temperature below the normal boiling point of the contaminants; and recovering the contaminants from the soil through the hollow perforated electrodes.
Claim 3
Dependent Claim 13 words
The method of claim 1 wherein the impermeable barrier is a flexible sheet.
Claim 4
Dependent Claim 29 words
The method of claim 1 wherein the impermeable barrier is a clay layer disposed on the surface of the soil and rendered impermeable by the application of said vacuum.
Claim 5
Dependent Claim 39 words
The method of claim 1 comprising the additional step of applying said vacuum to the soil through the pattern of electrodes, before electrically heating the soil, to avoid dispersion of contaminants and to remove excess water from the soil.
Claim 6
Dependent Claim 29 words
The method of claim 1 comprising the additional step of injecting water or steam through the pattern of electrodes and into the soil, to enhance the soil's electrical conductivity.
Claim 7
Dependent Claim 45 words
The method of claim 1, comprising the additional step of injecting a fluid into the soil through a first group of electrodes while applying a vacuum to the soil through a second group of electrodes, to further remove or decompose the contaminants in the soil.
Claim 8
Dependent Claim 17 words
The method of claim 6 wherein the fluid injected into the soil is hot water or steam.
Claim 9
Dependent Claim 25 words
The method of claim 1 comprising the additional step of introducing a fluid to the soil at the surface to enhance the soil's electrical conductivity.
Claim 10
Dependent Claim 36 words
The method of claim 1 comprising the additional step of introducing a fluid to the soil at the surface, while applying a vacuum to the soil, to further remove or decompose the contaminants in the soil.
Claim 11
Independent Claim 134 words
A method for the remediation and decontamination of surface and near-surface soils comprising the steps of: implanting a pattern of solid electrodes into the soil; installing a pattern of hollow perforated production wells into the soil such that the production wells are situated between said electrodes; covering the surface of the soil with an impermeable barrier; applying a vacuum of greater than 2 psia to the soil through the production wells; electrically heating the soil by conduction heating at power line frequencies through the pattern of electrodes wherein the soil is electrically heated to a temperature between 50° C. and no more than 99° C.; vaporizing contaminants in the soil at a temperature below the normal boiling point of the contaminants; and recovering the contaminants from the soil through said hollow, perforated production wells.
Claim 12
Independent Claim 134 words
A method for the remediation and decontamination of surface and near-surface soils comprising the steps of: implanting a pattern of solid electrodes into the soil; installing a pattern of hollow perforated production wells into the soil such that the production wells are situated between said electrodes; covering the surface of the soil with an impermeable barrier; applying a vacuum of greater than 2 psia to the soil through the production wells; electrically heating the soil by conduction heating at power line frequencies through the pattern of electrodes wherein the soil is electrically heated to a temperature between 50° C. and no more than 99° C.; vaporizing contaminants in the soil at a temperature below the normal boiling point of the contaminants; and recovering the contaminants from the soil through said hollow, perforated production wells.
Claim 13
Dependent Claim 13 words
The method of claim 10 wherein said impermeable barrier is a flexible sheet.
Claim 14
Dependent Claim 29 words
The method of claim 10 wherein the impermeable barrier is a clay layer disposed on the surface of the soil and rendered impermeable by the application of said vacuum.
Claim 15
Dependent Claim 38 words
The method of claim 10 comprising the additional step of applying said vacuum to the soil through the production wells, before electrically heating the soil, to remove excess water from the soil and to avoid dispersion of contaminants.
Claim 16
Independent Claim 114 words
A method for remediation and decontamination of surface and near-surface soils comprising the steps of: implanting a pattern of hollow perforated electrodes into the soil; covering the surface of the soil with an impermeable flexible sheet; applying a vacuum of greater than 2 psia to the soil through said pattern of hollow perforated electrodes; electrically heating the soil by conduction heating at power line frequencies through said pattern of hollow perforated electrodes to a temperature of from about 50° C. to about 99° C.; vaporizing contaminants in the soil at a temperature below the normal boiling point of the contaminants; and recovering the contaminants from the soil through said pattern of hollow perforated electrodes.
Claim 17
Independent Claim 114 words
A method for remediation and decontamination of surface and near-surface soils comprising the steps of: implanting a pattern of hollow perforated electrodes into the soil; covering the surface of the soil with an impermeable flexible sheet; applying a vacuum of greater than 2 psia to the soil through said pattern of hollow perforated electrodes; electrically heating the soil by conduction heating at power line frequencies through said pattern of hollow perforated electrodes to a temperature of from about 50° C. to about 99° C.; vaporizing contaminants in the soil at a temperature below the normal boiling point of the contaminants; and recovering the contaminants from the soil through said pattern of hollow perforated electrodes.
Claim 18
Dependent Claim 54 words
The method of claim 14 comprising the additional step of injecting hot water or steam into the soil through a first group of electrodes while applying a vacuum to the soil through a second group of electrodes, to further recover or decompose the contaminants in the soil, after electrically heating and vaporizing the contaminants.
Claim 19
Independent Claim 134 words
A method for the remediation and decontamination of surface and near-surface soils comprising the steps of: implanting a pattern of hollow, perforated electrodes into the soil; installing a pattern of hollow, perforated production wells into the soil; covering the surface of the soil with an impermeable barrier; applying a vacuum of greater than 2 psia to the soil through said production wells; injecting a fluid into the soil through said electrodes; electrically heating the soil by conduction heating at power line frequencies through said pattern of electrodes wherein the soil is electrically heated to a temperature between 50° C. and no more than 99° C.; vaporizing contaminants in the soil at a temperature below the normal boiling point of said contaminants; and recovering said contaminants from the soil through said hollow, perforated production wells.
Claim 20
Independent Claim 134 words
A method for the remediation and decontamination of surface and near-surface soils comprising the steps of: implanting a pattern of hollow, perforated electrodes into the soil; installing a pattern of hollow, perforated production wells into the soil; covering the surface of the soil with an impermeable barrier; applying a vacuum of greater than 2 psia to the soil through said production wells; injecting a fluid into the soil through said electrodes; electrically heating the soil by conduction heating at power line frequencies through said pattern of electrodes wherein the soil is electrically heated to a temperature between 50° C. and no more than 99° C.; vaporizing contaminants in the soil at a temperature below the normal boiling point of said contaminants; and recovering said contaminants from the soil through said hollow, perforated production wells.
Claim 21
Dependent Claim 17 words
The method of claim 16 wherein the fluid injected into the soil is hot water or steam.
Claim 22
Dependent Claim 25 words
The method of claim 16 comprising the additional step of introducing a fluid to the soil at the surface to enhance the soil's electrical conductivity.
Claim 23
Independent Claim 129 words
A method for remediation and decontamination of surface and near-surface soils comprising the steps of: implanting a pattern of hollow perforated electrodes into the soil, the pattern comprising parallel rows of electrodes; covering the surface of the soil with an impermeable barrier; applying a vacuum to the soil said vacuum being greater than 2 psia at the perforations in the electrodes; electrically heating the soil by conduction heating at power line frequencies through the pattern of electrodes, the rows of electrodes alternately energized wherein the soil is electrically heated to a temperature between 50° C. and no more than 99° C.; vaporizing contaminants in the soil at a temperature below the normal boiling point of the contaminants; and recovering the contaminants from the soil through the hollow perforated electrodes.
Claim 24
Independent Claim 129 words
A method for remediation and decontamination of surface and near-surface soils comprising the steps of: implanting a pattern of hollow perforated electrodes into the soil, the pattern comprising parallel rows of electrodes; covering the surface of the soil with an impermeable barrier; applying a vacuum to the soil said vacuum being greater than 2 psia at the perforations in the electrodes; electrically heating the soil by conduction heating at power line frequencies through the pattern of electrodes, the rows of electrodes alternately energized wherein the soil is electrically heated to a temperature between 50° C. and no more than 99° C.; vaporizing contaminants in the soil at a temperature below the normal boiling point of the contaminants; and recovering the contaminants from the soil through the hollow perforated electrodes.
Claim 25
Dependent Claim 21 words
The method of claim 19 wherein spacing between electrodes in a row is small compared to spacing between rows of electrodes.
Claim 26
Dependent Claim 23 words
The method of claim 19 wherein spacing between rows of electrodes is at least three times the spacing between electrodes within the rows.
Claim 27
Dependent Claim 17 words
The method of claim 19 wherein the electrodes comprise solid, pointed lower tips of a nonconductive material.
Claim 28
Independent Claim 131 words
A method for remediation and decontamination of surface and near-surface soils comprising the steps of: implanting a pattern of hollow perforated electrodes into the soil, the pattern comprising parallel rows of electrodes; covering the surface of the soil with an impermeable barrier; applying a vacuum to the soil said vacuum being greater than 2 psia at the perforations in the electrodes; electrically heating the soil by conduction heating at power line frequencies through the pattern of electrodes, pairs of the rows of electrodes alternately energized wherein the soil is electrically heated to a temperature between 50° C. and no more than 99° C.; vaporizing contaminants in the soil at a temperature below the normal boiling point of the contaminants; and recovering the contaminants from the soil through the hollow perforated electrodes.
Claim 29
Independent Claim 131 words
A method for remediation and decontamination of surface and near-surface soils comprising the steps of: implanting a pattern of hollow perforated electrodes into the soil, the pattern comprising parallel rows of electrodes; covering the surface of the soil with an impermeable barrier; applying a vacuum to the soil said vacuum being greater than 2 psia at the perforations in the electrodes; electrically heating the soil by conduction heating at power line frequencies through the pattern of electrodes, pairs of the rows of electrodes alternately energized wherein the soil is electrically heated to a temperature between 50° C. and no more than 99° C.; vaporizing contaminants in the soil at a temperature below the normal boiling point of the contaminants; and recovering the contaminants from the soil through the hollow perforated electrodes.
Claim 30
Dependent Claim 21 words
The method of claim 23 wherein spacing between electrodes in a row is small compared to spacing between rows of electrodes.
Claim 31
Dependent Claim 23 words
The method of claim 23 wherein spacing between rows of electrodes is at least three times the spacing between electrodes within the rows.
Claim 32
Dependent Claim 17 words
The method of claim 23 wherein the electrodes comprise solid, pointed lower tips of a nonconductive material.

References Cited (Backward Citations)

US3732697A Cited
US4026355A Cited
USRE30738E Cited
US4545435A Cited
US4670634A Cited
US4895085A Cited
US4957393A Cited
US5249888A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 2000-08-11 2001-02-10 2001-08-12 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2004-08-11 2005-02-10 2005-08-12 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2008-08-11 2009-02-10 2009-08-12 $7700.00 Window Closed / Lapsed

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