Method and system for bioremediation of contaminated soil using inoculated diatomaceous earth

• US 5,570,973 A
• Filed: 07/11/1994
• Issued: 11/05/1996
• Est. Priority Date: 07/11/1994
• Status: Expired due to Fees

• Current Assignee: Seth C. Hunt
• Original Assignee: Foremost Solutions, Inc.
• Inventors: Hunt, Seth C.
• Primary Examiner(s): Suchfield, George A.
• Application Number:
  US08/272,816
• Time in Patent Office: 848 Days
• Field of Search: 405/128, 166/246, 166/280, 166/308, 210/601, 210/610, 210/901, 435/262, 435/262.5
• US Class Current: 405/128.15
• CPC Class Codes: B09C 1/002 involving in-situ ground water treatment
• CPC Class Codes: B09C 1/02 Extraction using liquids, e.g. washing, leaching , flotation
• CPC Class Codes: B09C 1/08 chemically
• CPC Class Codes: B09C 1/10 microbiologically, biologically or by using enzymes
• CPC Class Codes: B09C 2101/00 In situ
• CPC Class Codes: C02F 3/101 Arranged-type packing, e.g. stacks, arrays
• CPC Class Codes: E02D 3/00 Improving or preserving soil or rock, e.g. preserving permafrost soil securing of slopes or inclines E02D17/20; damming or interrupting passage of underground water E02D19/12; improving soil for agricultural purposes A01; soil stabilisation for road building or like purposes E01C21/00, E01C23/10; setting rock anchoring bolts E21D
• CPC Class Codes: Y02W 10/10 Biological treatment of water, waste water, or sewage

Abstract

A system for in-situ bioremediation of contaminated soil and ground water wherein porous inorganic support spheres such as diatomaceous earth pellets are treated by inoculation with selected non-pathogenic microbes, ie. bacteria, for destroying or converting the contaminate. The contaminates may be hydrocarbons, sulphides, cyanides, nitrates, heavy metals and other chemicals. The porous cells of the diatomaceous earth pellets provide a home not only for the microbes but also for oxygen, water and other nutrients to help sustain the life of the augmented colonies of microbes introduced in the pellets. The contaminated soil is prepared for treatment by creating fractures and fissures therein using fluid pressure introduced through spaced apart holes drilled to selected depths. The depth of the drilled holes and the hole spacing will depend on the area of contamination. The diatomaceous earth pellets, with microbes stored therein, are then injected into the spaces of the fractures and fissures using air or liquid pressure. The diatomaceous earth pellets may range in size from 0.1 to 1.0 microns or larger. When the inoculated pellets are in place, the microbes have a permanent home to receive contaminates and to work from in destroying the contaminates. The drilled holes may also be retrofited with perforated pipe for supplementing the microbes with additional oxygen, water and nutrients or adding more pellets with microbes therein for completing the clean up of the contaminated soil and ground water.

Claims

1. A method for in-situ bioremediation of contaminated soil and ground water wherein porous inorganic support spheres such as diatomaceous earth pellets are treated by inoculation with selected non-pathogenic microbes, ie. bacteria, for destroying or converting the contaminate, the steps comprising:

preparing and treating the contaminated soil by creating fractures and fissures therein using fluid pressure introduced through spaced apart drill holes drilled to selected depths;

inoculating cells of the porous inorganic support spheres with a selected microbe designed to destroy or convert the contaminate; and

introducing said support spheres with microbes under pressure into the fractures and fissures of the contaminated soil.

2. The method as described in claim 1 further including the step of installing a perforated pipe in each of said drill holes.

3. The method as described in claim 2 further including the step of introducing air, water and nutrients under pressure through said perforated pipe and into the fractures and fissures of the contaminated soil for supplementing the growth of the microbes in the support spheres, this step after the step of introducing said support spheres with microbes under pressure.

4. The method as described in claim 3 further including the step of introducing additional support spheres with microbes under pressure through said perforated pipe and into the fractures and fissures of the contaminated soil and for supplementing and adding to the bioremediation of the contaminated soil and ground water, this step after the step of introducing air, water and nutrients under pressure.

5. The method as described in claim 1 wherein the step of preparing and treating the contaminated soil by creating fractures and fissures therein using fluid pressure includes the drilling of spaced apart drill holes in a grid pattern surrounding the contaminated soil, said drill holes drilled to a depth of 10 to 20 feet and greater.

6. The method as describe in claim 1 wherein the step of inoculating the cells of the porous inorganic support spheres includes inoculating with a microbe common to the natural occurring bacteria found in the contaminate soil and surrounding area.

7. A method for in-situ bioremediation of contaminated soil and ground water wherein porous inorganic support spheres are treated by inoculation with selected non-pathogenic microbes, ie. bacteria, for destroying or converting the contaminate, the steps comprising:

preparing and treating the contaminated soil by creating fractures and fissures therein using fluid pressure introduced through spaced apart drill holes drilled in a grid pattern to selected depths and surrounding the contaminated soil;

inoculating cells of the porous inorganic support spheres with a selected microbes common to the naturally surrounding bacteria found in the contaminated soil and designed to destroy or convert the contaminate;

introducing said support spheres with microbes under air pressure into the fractures and fissures of the contaminated soil; and

introducing air, water and nutrients into the fractures and fissures with the support spheres and microbes to supplement the growth of the microbes in the support spheres.

8. The method as described in claim 7 further including the step of installing a perforated pipe in each of said drill holes in the grid pattern.

9. The method as described in claim 8 further including the step of introducing additional support spheres with microbes under air pressure through said perforated pipe and into the fractures and fissures of the contaminated soil and for supplementing and adding to the bioremediation of the contaminated soil and ground water.

10. The method as described in claim 9 further including the step of introducing additional air, water and nutrients with the support spheres and microbes under pressure through said perforated pipe and into the fractures and fissures of the contaminated soil and for supplementing and adding to the bioremediation of the contaminated soil and ground water.

11. The method as described in claim 7 wherein the step of preparing and treating the contaminated soil by creating fractures and fissures therein using fluid pressure includes the drilling of spaced apart drill holes in the grid pattern to a depth of 10 to 20 feet and greater.

12. The method as described in claim 7 wherein the support spheres are in the form of pellets.

13. A method for in-situ bioremediation of contaminated soil and ground water wherein porous inorganic support spheres are treated by inoculation with selected non-pathogenic microbes, ie. bacteria, for destroying or converting the contaminate, the steps comprising:

preparing and treating the contaminated soil by creating fractures and fissures therein using fluid pressure introduced through spaced apart drill holes drilled in a grid pattern to selected depths and surrounding the contaminated soil;

inoculating cells of the porous inorganic support spheres of diatomaceous earth pellets with a selected microbes common to the naturally surrounding bacteria found in the contaminated soil and designed to destroy or convert the contaminate;

introducing said support spheres with microbes under air pressure into the fractures and fissures of the contaminated soil; and

installing a perforated pipe in each of said drill holes in the grid pattern for introducing additional support spheres with microbes, air, water and nutrients into the fractures and fissures to supplement the growth of the microbes in the support spheres.