Systems and methods for in situ soil sterilization, insect extermination and weed killing

• US 20030215354A1
• Filed: 09/16/2002
• Published: 11/20/2003
• Est. Priority Date: 05/17/2002
• Status: Abandoned Application

• Current Assignee: Agency For Science Technology and Research (Government of Singapore)
• Original Assignee: Agency For Science Technology and Research (Government of Singapore)
• Inventors: Clark, William J., Kissell, Charles W.
• Application Number:
  US10/245,787
• Publication Number:
  US 20030215354A1
• Time in Patent Office: Days
• US Class Current: 422/22
• CPC Class Codes: A01G 11/00 Sterilising soil by steam
• CPC Class Codes: A01M 19/00 Apparatus for the destruction of noxious animals, other than insects, by hot water, steam, hot air, or electricity electric traps A01M23/38
• CPC Class Codes: A01M 21/046 by electricity
• CPC Class Codes: A61L 2/12 Microwaves
• CPC Class Codes: B09C 1/06 thermally
• CPC Class Codes: H05B 2206/045 Microwave disinfection, sterilization, destruction of waste...
• CPC Class Codes: H05B 6/80 Apparatus for specific applications stoves or ranges F24C7/02

Abstract

Systems, methods and devices for in situ soil sterilization using contained microwave energy, and more specifically methods and devices for removing from the soil to a specified depth in situ substantially all biological pests. The method comprises exposing the specified depth of soil to sufficient energy flux, within a sufficiently short exposure time, of microwave frequency electromagnetic radiation at a frequency tuned to dissociate biopolymers. The device comprises: a source of microwave frequency electromagnetic radiation; a carriage; and, optionally a radiation shield and a cooling system. The carriage moves the source of electromagnetic radiation to an area for treatment and the radiation shield prevents leakage of radiation to undesired points. The cooling system maintains the device at a sufficiently cool temperature for reliable operation.

Claims

1. A method of sterilizing soil, comprising:

positioning at least one microwave frequency electromagnetic radiation generating element proximal a region of soil to be sterilized, said generating element being tuned to generate microwave radiation at a frequency sufficient to interact with carbon-carbon bonds; and

generating microwave radiation at said frequency for an amount of time and at a sufficient power to generate a microwave energy flux sufficient to render non-viable any organisms in said region to a specified depth.

2. The method of claim 1, wherein the specified depth is between about 1 foot and about 4 feet.

3. The method of claim 1, wherein the specified depth is greater than about 4 feet.

4. The method of claim 1, wherein said generating element has a power output of at least about 30 kilowatts.

5. The method of claim 4, wherein the amount of time is between about 0.5 seconds and about 5 seconds.

6. The method of claim 4, wherein the amount of time is greater than about 5 seconds.

7. The method of claim 1, wherein the sufficient microwave energy flux is at least about 9000 joules per square foot.

8. The method of claim 1, wherein positioning includes mounting the at least one microwave frequency electromagnetic radiation generating element on a carriage stricture, and moving said carriage structure over said region of soil.

9. The method of claim 1, wherein said at least one microwave frequency electromagnetic radiation generating element is stationary, and wherein positioning includes moving said region of soil relative to said stationary radiation generating element.

10. The method of claim 1, wherein said frequency is between about 2.48 GHz and about 2.52 GHz.

11. A method of removing pests from soil to a specified depth, in situ, the method comprising exposing an area of soil to a sufficient energy flux, within a sufficiently short exposure time, of microwave frequency electromagnetic radiation at a frequency tuned to sufficiently damage all nucleic sequence information and biomacromolecules having information content such that substantially all organisms are rendered non-viable in said area to the specified depth.

12. The method of claim 11, wherein the specified depth of soil treatment is about 0.5 feet to about 4 feet.

13. The method of claim 11, wherein the specified depth of soil treatment is greater than about 4 feet.

14. The method of claim 11, wherein the pests include one or more of microbes, weeds, seeds, nematodes, and insects in the soil.

15. The method of claim 11, wherein exposing includes applying a minimum power flux of microwave frequency electromagnetic radiation of at least about 1800 watts per square foot to the surface of the soil.

16. The method of claim 11, wherein the source of microwave frequency electromagnetic radiation comprises one of a single microwave emitting element and an array of microwave emitting elements.

17. The method of claim 16, wherein each microwave radiation emitting element has a power output of at least about 30 kilowatts.

18. The method of claim 16, wherein the microwave frequency electromagnetic radiation is applied to the surface of said area for between about 0.5 seconds and about 5 seconds so as to provide a soil surface radiation energy flux of at least about 9000 joules per square foot.

19. A method of reconstituting an altered soil microbial balance resulting from a soil insult to a pre-alteration microbial balance, comprising:

exposing an area of soil to sufficient energy flux, within a sufficiently short exposure time, of microwave frequency electromagnetic radiation at a frequency tuned to sufficiently damage nucleic sequence information and biomacromolecules having information content so as to produce an area of treated soil that is substantially sterile to a specified depth; and

inoculating the area of treated soil with one or more microbes to produce an inoculated area of treated soil,

wherein the inoculation reintroduces microbes required to reconstitute the pre-alteration microbial balance; and

wherein under ambient conditions the inoculated area of treated soil obtains a pre-alteration microbial balance at an earlier time than may be obtained by removing the soil insult.

20. The method of claim 20, wherein the specified depth of soil treatment is about ½

foot to about 4 feet.

21. The method of claim 20, wherein the specified depth of soil treatment is greater than about 4 feet.

22. The method of claim 20, wherein a soil surface radiation power flux of at least 1800 watts per square foot is delivered to the area of soil for an adequate time to yield a soil surface radiation energy flux of at least about 9000 joules per square foot.

23. A method of altering soil microbial balance to a desired microbial balance, comprising:

removing from the soil to a specified depth in situ substantially all biological information by a treatment comprising exposing the specified depth of soil to sufficient energy flux, within a sufficiently short exposure time, of microwave frequency electromagnetic radiation at a frequency tuned to dissociate biomacromolecules having information content to produce an area of treated soil that is substantially sterile to the specified depth; and

inoculating the area of treated soil with one or more microbes to produce an inoculated area of treated soil, wherein the inoculation introduces microbes required to constitute the desired microbial balance; and

wherein under ambient conditions the inoculated area of treated soil obtains the desired microbial balance.

24. A device for in situ treatment of soil comprising:

a source of microwave frequency electromagnetic radiation; and

a carriage;

wherein the carriage is configured to move the source of electromagnetic radiation to expose the soil to a sufficient radiation energy flux within a sufficiently short exposure time to a specified depth so as to sufficiently damage all nucleic sequence information such that substantially all organisms contained in the soil are rendered non-viable to the specified depth.

25. The device of claim 24, further comprising a radiation shield configured to prevent leakage of radiation to undesired areas.

26. The device of claim 24, wherein the microwave frequency electromagnetic radiation generated by the source has a frequency between about 2.4 GHz to about 2.6 GHz.

27. The device of claim 24, wherein the microwave frequency electromagnetic radiation generated by the source has a frequency between about 2.48 GHz to about 2.52 GHz.

28. The device of claim 24, wherein the source includes one of a single microwave radiation emitting element and an array of microwave radiation emitting elements.

29. The device of claim 28, wherein each microwave radiation emitting element has a power output of at least 30 kilowatts.

30. The device of claim 24, further including a radiation shield comprising one of a matter barrier and an electromagnetic field barrier.

31. The device of claim 24, further including a cooling system configured to maintain the device at a sufficiently cool temperature during operation.

32. The device of claim 31, wherein the cooling system comprises a water jacket and a pump for circulating water in the water jacket.

33. The device of claim 24, wherein the carriage comprises a drive train operably linked to a mechanical assembly comprising a weight bearing portion selected from the group consisting of one or more wheels, a cog and a track.

34. The device of claim 33, wherein the weight bearing portion is a cog, and the carriage moves in a path determined by a rail or wire.

35. The device of claim 24, wherein the carriage comprises a steer able motor vehicle riding on wheels, tracks or a combination thereof.

36. The device of claim 24, wherein when the carriage is fixed in place, a radiation flux is delivered to an area of up to about 160 square feet.

37. A device for in situ treatment of soil comprising:

a source of microwave frequency electromagnetic radiation;

a carriage;

a radiation shield; and

a cooling system

wherein the carriage moves the source of microwave frequency electromagnetic radiation to expose the soil to a sufficient radiation flux to a specified depth for a sufficient time to destroy or render non-viable all nucleic sequence information contained in the soil to the specified depth, wherein the radiation shield prevents leakage of radiation to undesired points, and wherein the cooling system maintains the device at a sufficiently cool temperature to permit safe operation and adequate durability of materials used in components of the device.

38. The device of claim 37, further comprising a carriage operation station for controlling movement of the carriage.

39. The device of claim 38, wherein the carriage operation station includes operational controls and a processor control interface, the operational controls controllable by a processor or manually by an operator.

40. The device of claim 38, further comprising a processor with input from sensors and output to one or both of the processor control interface and a graphical interface, wherein the carriage being operated from the carriage operation station by an operator manually or by the processor with operator override, and wherein the processor control interface provides the operator with information from the processor.