Removal of volatile contaminants from the vadose zone of contaminated ground
First Claim
Patent Images
1. A process for removing a not-naturally-occurring, volatile liquid contaminant from a contaminated araa of the earth, wherein the contaminated area of the earth has a subsurface water table and a subsurface vadose zone above the water table, the contaminant being present in the vadose zone, which comprises the steps of:
- establishing a borehole extending downwardly from the surface of the ground within the contaminated area;
placing a first conduit within said borehole so that a ring-shaped zone is formed between the wall of said borehole and said conduit, said conduit having a perforate lower portion located in the vadose zone and spaced vertically above the water table so that fluids can flow from the vadose zone into the interior of said conduit, said perforate lower portion having an upper end and a lower end, said conduit having an imperforate upper portion above the upper end of said perforate lower portion.[.,.]..Iadd.;
.Iaddend.filling fluid-permeable first fill material into a lower portion of said ring-shaped zone around said perforate lower portion of said conduit and which extends to the upper end of said perforate lower portion so that said first fill material will permit fluid readily to flow into said perforate lower portion of said conduit;
filling a second fill material of low fluid permeability into an upper portion of said ring-shaped zone around said imperforate upper portion of said conduit, said second fill material being effective to impede flow of air from the surface of the ground to the lower portion of the borehole;
applying a vacuum to the upper end of said conduit effective to induce flow of air and a gas containing vapor of said contaminant present in said vadose zone into the lower portion of said conduit and thence to the upper end of said conduit, the vacuum being effective to cause vaporization of a substantial quantity of said contaminant within the vadose zone around the borehole so that said contaminant is removed from the ground in vapor form.
1 Assignment
0 Petitions
Accused Products
Abstract
Volatile contaminants are removed from the vadose zone of contaminated ground by pumping volatilized contaminants from the vadose zone using one or more vacuum extraction wells.
-
Citations
8 Claims
-
1. A process for removing a not-naturally-occurring, volatile liquid contaminant from a contaminated araa of the earth, wherein the contaminated area of the earth has a subsurface water table and a subsurface vadose zone above the water table, the contaminant being present in the vadose zone, which comprises the steps of:
-
establishing a borehole extending downwardly from the surface of the ground within the contaminated area; placing a first conduit within said borehole so that a ring-shaped zone is formed between the wall of said borehole and said conduit, said conduit having a perforate lower portion located in the vadose zone and spaced vertically above the water table so that fluids can flow from the vadose zone into the interior of said conduit, said perforate lower portion having an upper end and a lower end, said conduit having an imperforate upper portion above the upper end of said perforate lower portion.[.,.]..Iadd.;
.Iaddend.filling fluid-permeable first fill material into a lower portion of said ring-shaped zone around said perforate lower portion of said conduit and which extends to the upper end of said perforate lower portion so that said first fill material will permit fluid readily to flow into said perforate lower portion of said conduit; filling a second fill material of low fluid permeability into an upper portion of said ring-shaped zone around said imperforate upper portion of said conduit, said second fill material being effective to impede flow of air from the surface of the ground to the lower portion of the borehole; applying a vacuum to the upper end of said conduit effective to induce flow of air and a gas containing vapor of said contaminant present in said vadose zone into the lower portion of said conduit and thence to the upper end of said conduit, the vacuum being effective to cause vaporization of a substantial quantity of said contaminant within the vadose zone around the borehole so that said contaminant is removed from the ground in vapor form. - View Dependent Claims (2)
-
-
3. A process for removing a not-naturally-occurring, volatile liquid contaminant from a contaminated area of the earth, wherein the contaminated area of the earth has a subsurface water table and a subsurface vadose zone above the water table, the contaminant being present in the vadose zone, which comprises the steps of:
-
delineating the extent, thickness and contents of the contaminant and also determining its direction and rate of spreading in the vadose zone; establishing at least one borehole extending downwardly from the surface of the ground within the .[.contaiminated.]. .Iadd.contaminated .Iaddend.area; placing a first conduit within said borehole so that a ring-shaped zone is formed between the wall of said borehole and said conduit, said conduit having a perforate lower portion located in the vadose zone and spaced vertically above the water table so that fluids can flow from the vadose zone into the interior of said conduit, said perforate lower portion having an upper end and a lower end, said conduit having an imperforate upper portion above the upper end of said perforate lower portion.[.,.]..Iadd.;
.Iaddend.filling fluid-permeable first fill material into a lower portion of said ring-shaped zone around said perforate lower portion of said conduit and which extends to the upper end of said perforate lower portion so that said first fill material will permit fluid readily to flow into said perforate lower portion of said conduit; filling a second fill material of low fluid permeability into an upper portion of said ring-shaped zone around said imperforate upper portion of said conduit, said second fill material being effective to impede flow of air from the surface of the ground to the lower portion of the borehole; applying a vacuum to the upper end of said conduit effective to induce only flow of air and a gas containing vapor of said contaminant present in said vadose zone into the lower portion of said conduit and thence to the upper end of said conduit, the vacuum being effective to cause vaporization of a substantial quantity of said contaminant within the vadose zone around the borehole so that said contaminant is removed from the ground in vapor form. - View Dependent Claims (4, 5, 6, 7)
-
-
8. A process for decontaminating an underground vadose zone which is located above the water table and is contaminated with a volatile liquid contaminant which is percolating downwardly through said vadose zone, which comprises:
-
establishing a vacuum extraction well comprising a well casing having a perforate lower portion located in the contaminated vadose zone and above the water table so that fluids can flow from said contaminated vadose zone into said perforate lower portion of said well casing, the area around said vacuum extraction well casing above said perforate lower portion being substantially sealed to impede flow of air around said well casing from the surface of the ground to said perforate lower portion of said well casing; applying a vacuum through said vacuum extraction well to said perforate lower portion of said well casing, said vacuum being effective to draw air through said contaminated vadose zone and to volatilize liquid contaminant that is present in said contaminated vadose zone above the water table and surrounding said perforate lower portion of said well .[.caisng.]. .Iadd.casing .Iaddend.the vapor containing the volatilized liquid contaminant being drawn into said well casing and thence being transported to a location above ground.
-
Specification