AU732848B2 - Method of ground treatment - Google Patents
Method of ground treatment Download PDFInfo
- Publication number
- AU732848B2 AU732848B2 AU35330/97A AU3533097A AU732848B2 AU 732848 B2 AU732848 B2 AU 732848B2 AU 35330/97 A AU35330/97 A AU 35330/97A AU 3533097 A AU3533097 A AU 3533097A AU 732848 B2 AU732848 B2 AU 732848B2
- Authority
- AU
- Australia
- Prior art keywords
- ground
- solution
- water
- volume
- soil
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Ceased
Links
- 238000000034 method Methods 0.000 title claims description 27
- 239000000243 solution Substances 0.000 claims description 51
- 239000002689 soil Substances 0.000 claims description 40
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 27
- 239000002245 particle Substances 0.000 claims description 25
- VSGNNIFQASZAOI-UHFFFAOYSA-L calcium acetate Chemical compound [Ca+2].CC([O-])=O.CC([O-])=O VSGNNIFQASZAOI-UHFFFAOYSA-L 0.000 claims description 21
- 229960005147 calcium acetate Drugs 0.000 claims description 21
- 239000001639 calcium acetate Substances 0.000 claims description 21
- 235000011092 calcium acetate Nutrition 0.000 claims description 21
- BPQQTUXANYXVAA-UHFFFAOYSA-N Orthosilicate Chemical compound [O-][Si]([O-])([O-])[O-] BPQQTUXANYXVAA-UHFFFAOYSA-N 0.000 claims description 16
- 239000000356 contaminant Substances 0.000 claims description 16
- 159000000007 calcium salts Chemical class 0.000 claims description 13
- BHPQYMZQTOCNFJ-UHFFFAOYSA-N Calcium cation Chemical compound [Ca+2] BHPQYMZQTOCNFJ-UHFFFAOYSA-N 0.000 claims description 10
- 239000004115 Sodium Silicate Substances 0.000 claims description 10
- 229910001424 calcium ion Inorganic materials 0.000 claims description 10
- 229910052911 sodium silicate Inorganic materials 0.000 claims description 10
- NTHWMYGWWRZVTN-UHFFFAOYSA-N sodium silicate Chemical compound [Na+].[Na+].[O-][Si]([O-])=O NTHWMYGWWRZVTN-UHFFFAOYSA-N 0.000 claims description 9
- 239000003349 gelling agent Substances 0.000 claims description 4
- 238000009877 rendering Methods 0.000 claims description 4
- 150000003839 salts Chemical class 0.000 claims description 4
- 229920001817 Agar Polymers 0.000 claims description 3
- 239000008272 agar Substances 0.000 claims description 3
- 239000012466 permeate Substances 0.000 claims description 3
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 claims description 2
- 239000007864 aqueous solution Substances 0.000 claims description 2
- 239000011575 calcium Substances 0.000 claims description 2
- 229910052791 calcium Inorganic materials 0.000 claims description 2
- 239000000499 gel Substances 0.000 claims description 2
- 239000003440 toxic substance Substances 0.000 description 8
- 239000010410 layer Substances 0.000 description 7
- 231100000614 poison Toxicity 0.000 description 6
- 238000002347 injection Methods 0.000 description 5
- 239000007924 injection Substances 0.000 description 5
- 239000000463 material Substances 0.000 description 5
- 230000000694 effects Effects 0.000 description 4
- 238000002386 leaching Methods 0.000 description 4
- 239000000203 mixture Substances 0.000 description 4
- 239000004927 clay Substances 0.000 description 3
- 238000010521 absorption reaction Methods 0.000 description 2
- 229910052918 calcium silicate Inorganic materials 0.000 description 2
- 238000011109 contamination Methods 0.000 description 2
- 231100000167 toxic agent Toxicity 0.000 description 2
- 239000000080 wetting agent Substances 0.000 description 2
- 241000779819 Syncarpia glomulifera Species 0.000 description 1
- VEUACKUBDLVUAC-UHFFFAOYSA-N [Na].[Ca] Chemical compound [Na].[Ca] VEUACKUBDLVUAC-UHFFFAOYSA-N 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 239000000378 calcium silicate Substances 0.000 description 1
- OYACROKNLOSFPA-UHFFFAOYSA-N calcium;dioxido(oxo)silane Chemical compound [Ca+2].[O-][Si]([O-])=O OYACROKNLOSFPA-UHFFFAOYSA-N 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 238000004090 dissolution Methods 0.000 description 1
- 239000003673 groundwater Substances 0.000 description 1
- 230000000977 initiatory effect Effects 0.000 description 1
- 229910052500 inorganic mineral Inorganic materials 0.000 description 1
- 230000003993 interaction Effects 0.000 description 1
- 239000011159 matrix material Substances 0.000 description 1
- 239000011707 mineral Substances 0.000 description 1
- 238000005065 mining Methods 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 239000001739 pinus spp. Substances 0.000 description 1
- 238000001556 precipitation Methods 0.000 description 1
- 238000007789 sealing Methods 0.000 description 1
- 238000005507 spraying Methods 0.000 description 1
- 239000002344 surface layer Substances 0.000 description 1
- 229940036248 turpentine Drugs 0.000 description 1
- 235000015112 vegetable and seed oil Nutrition 0.000 description 1
- 239000008158 vegetable oil Substances 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
Landscapes
- Processing Of Solid Wastes (AREA)
- Soil Working Implements (AREA)
- Excavating Of Shafts Or Tunnels (AREA)
Description
WO 98/04649 PCT/AU97/00476 -1- Title METHOD OF GROUND TREATMENT Technical field The present invention relates to a method of treating a volume of ground for the purposes of rendering the volume or area of ground impervious to water.
Background of the invention Toxic substances present in soil arise typically from the dumping or burying of waste material into the soil. The toxic substances include those that are formed from the leaching of toxic substances from tailings dumps in the minerals and mining industry. The leaching of these toxic substances in the soil provides a danger to the surrounding environment.
The present invention seeks to overcome or minimise the above stated problem.
Throughout the specification the term ground shall be taken to include a body of ground or soil which may be located at the surface or below the surface and which may, or may not be waterbearing.
Summary of the invention According to one form of the present invention, there is provided a method of rendering a volume of ground substantially impermeable to water comprising applying to the ground a water soluble calcium salt, allowing the calcium ions in the salt to permeate the ground and then applying an aqueous silicate solution.
According to a preferred feature of the invention the calcium salt comprises an aqueous solution of calcium acetate.
WO 98/04649 PCT/AU97/00476 -2- According to a further preferred feature of the invention the calcium salt comprises the salt in an undissolved form According to a still further preferred feature of the invention the calcium salt comprises porous particles of calcium acetate.
According to one particular embodiment incorporating this feature the calcium salt is present as agglomerated particles which are distributed over the surface of the ground or under the surface in the vicinity of the surface. The agglomerated particles can comprise porous particles of calcium acetate or a mixture of calcium acetate with a gelling agent such as agar According to a further preferred feature of the invention a silicate solution comprises a solution of sodium silicate.
According to one embodiment of the invention the water soluble calcium salt and sodium silicate are applied over the surface of the ground.
According to another embodiment of the invention the water soluble calcium salt -and sodium silicate are introduced into the ground below the surface.
According to another embodiment the ground comprises the bed of a body of water.
Description of preferred embodiments The invention will be more fully understood in the light of the description of several specific embodiments of the invention.
The first embodiment comprises a method of treating an area of soil for the purposes of rendering that area of soil waterproof. The embodiment has particular application in circumstances where it is desired to form the bed of an artificial lake or dam.
WO 98/04649 PCT/AU97/00476 -3- The embodiment comprises spraying over the area of soil to be treated a solution of calcium acetate in sufficient quantity to allow the calcium acetate solution to soak into and permeate the upper layer of soil. If desired a suitable wetting agent may be added to the solution to ensure adequate absorption of the solution into the soil. Subsequent to the treatment of the upper layer of soil a solution of sodium silicate is then sprayed over the surface in sufficient quantity to react with the calcium acetate solution to form a layer which is impervious to water and again if desired a suitable wetting agent may be added to the solution to ensure adequate absorption of the solution into the soil. If desired the treatment process may require several sequential applications of the calcium and silicate solutions.
The embodiment may be used in treating the intended floor of an artificial lake or dam subsequent to the area having been lined with a suitable clay composition vher.eby the treatment provided by the embodiment serves to enhance the water sealing characteristics of the clay composition and to overcome any difficulties which may be created as a result of imperfections in the clay layer.
The second embodiment of the invention comprises an application which is similar to that of the first embodiment (ie treatment of a surface layer of soil to form the bed of an intended lake or dam). In the case of the second embodiment the calcium acetate is applied to the soil in the form of particles. The particles are formed of calcium acetate which are formed to be porous. The porosity of the particles enhances the contact between the calcium acetate and the water and the dissolution of the calcium acetate into the water. The particles are spread over the surface of the soil and is mixed with the surface such that it is substantially evenly distributed through the top layer of the soil. If the soil is not already wet it is then sprayed with water. The nature of the particle ensures that on the particle becoming embodied in the soil the calcium acetate solution will leach from the particles into the surrounding soil. In order to retard the solution process such that it will only occur after the particles have become fully embodied in the soil the particles can be coated with a material which will retard WO 98/04649 PCT/AU97/00476 -4the solution process. Such a coating may comprise turpentine, or a vegetable oil or a similar agent which will retard the transfer of the calcium acetate from the particles into the solution. After the particles have been introduced into the soil and sufficient time has been allowed to permit the calcium acetate to leach from the particles into the surrounding soil (approximately 10 to 15 minutes) then the sodium silicate solution is introduced into the soil. It is preferred that the sodium silicate be injected into the soil into the region in which the particles have been introduced and that it be introduced in the form of a concentrated gel.
According a further embodiment which is a variation of the previous embodiment the particles containing the calcium acetate can comprise the calcium acetate mixed with a gelling agent such as agar where the mixture is allowed to dry and is formed into discrete particles.
According to a preferred feature of each of the embodiments, the treatment of the soil with the solution of calcium acetate can be accompanied by application of a weak cementitious solution which is introduced into dry broken or friable soil. The application of this solution serves to enhance the bonding of soil particles and also serves to increase the concentration of calcium ions which are available for interaction with the sodium silicate solution.
The third embodiment of the invention relates to the treatment of a volume of soil which may be located in the region of the surface or be subterranean. The function of the embodiment is to serve in bonding together the soil particles in that volume to render the volume of soil substantially impervious to water thereby entrapping any materials which are contained within that volume of soil.
This embodiment has particular application to the treatment of contaminated soil for the purposes of preventing further seepage of a contaminant which may be contained in the ground and limiting any further leaching of the contaminants into the surrounding soil. The embodiment can also have application to isolate toxic substances which have entered the ground water by treating a "plumes" of toxic substances which may be contained in the water table or an aquifer to effect WO 98/04649 PCT/AU97/00476 containment of the plume. The method according to the embodiment comprises identifying the volume of soil which is affected by the contaminants and introducing into that volume of soil a solution of calcium acetate solution and then injecting a solution of sodium silicate into the area containing the calcium ions in order to effect precipitation of calcium silicate from solution and a bonding between the adjacent soil particles. The process may necessitate a repeated application of the calcium ion solution and the sodium silicate solution into the volume of ground at closely adjacent positions until the affected volume of ground has been suitably treated.
In the case of an advancing plume of contamination the method may comprise a sequential injection of the calcium ion and silicate solutions along a line which is in advance of the plume of contaminants in order to prevent the further advance of those contaminates through an aquifer or water table and then subsequently treat ground to either side, below and to the rear of the plume in order to surround the contaminant plume and effectively create a cell in which the contaminants can be contained. Once so contained the volume of ground within the cell can then be treated with the calcium ion solution and silicate solution in order to bond the soil particles contained within that cell and entrap the contaminants within that volume.
In circumstances where the contaminants are contained in a layer of soil and are descending downwardly it may be appropriate to initially treat a layer of soil below the contaminants and to each side of the area of contamination in order to contain the contaminants within the defined area and prevent the further spread of those contaminants.
One means of effecting the injection of each solution when carrying out the above embodiment comprises locating an injection tube such that it is located below the area to be treated and then raising the end of the tube through the zone to be treated whilst forcing the required solution from the end of the tube.
This action is repeated at spaced locations over the area to be treated for each WO 98/04649 PCT/AU97/00476 -6solution. In order to allow for the required distribution of the calcium ion solution it may be necessary to delay the introduction of the silicate solution by some 12 to 24 hours.
The effect of the embodiment is to bond the contaminants into a matrix which is at most slow to dissolve in order to limit the creation of a leachate and/or to prevent the mixing of the contaminant with another which may result in the initiating of an undesirable reaction from which can evolve a toxic substance.
Another embodiment relates to a circumstance where it is necessary to prevent drainage of leachate from a body of water bearing material. This can have relevance in controlling the leaching of toxic substance from tailings dumps where the water from the tailing dump is leaking into the ground formation. The embodiment comprises introducing into the tailings material the calcium ion solution and silicate solution where the introduction is effected in a region closely surrounding or adjacent the suspected leakage zone. Such introduction is for the purpose of forming a volume of consolidated material which will be carried into the leakage zone to at least reduce or close the flow from the leakage zone.
One means of effecting the injection of each solution in order to effect this embodiment comprises locating an injection tube such that it is located below the area to be treated and then raising the end of the tube through the zone to be treated whilst forcing the required solution from the end of the tube. This action is repeated at spaced locations over the area to be treated for each solution. In order to allow for the required distribution of the calcium ion solution it may be necessary to delay the introduction of the silicate solution by some 12 to 24 hours.
It should be appreciated that the scope of the invention and application of the invention need not be limited to the particular scope of the embodiments described above.
Claims (16)
1. A method of rendering a volume of ground substantially impermeable to water including applying to the ground a water soluble calcium salt which includes an aqueous solution of calcium acetate, allowing the calcium ions in the salt to permeate the ground and then applying an aqueous silicate solution.
2. A method according to claim 1, wherein the calcium acetate is in a form of porous particles.
3. A method according to either one of claims 1 or 2, wherein the calcium o: salt is in an undissolved form.
4. A method according to either one of claims 1 or 2, wherein the water soluble calcium acetate solution is mixed with a gelling agent before being applied to the ground:
5. A method according to claim 4, wherein the gelling agent is agar.
6. A method according to any one of the preceding claims, wherein the aqueous silicate solution includes asolution of sodium silicate.
7. A method according to any one of the preceding claims, wherein the aqueous silicate solution is in a form of a concentrated gel.
8. A method according to any one of the preceding claims, wherein the water soluble calcium salt and the aqueous silicate solution are applied over a surface of the ground.
9. A method according to any one of the claims 1 to 7, wherein the water soluble calcium salt and the aqueous silicate solution are introduced below the surface of the ground.
A method according to any one of the preceding claims, wherein the volume of ground is a bed of a body of water.
11. A method according to any one of the preceding claims, wherein the steps of applying the water soluble calcium salt and subsequently the aqueous silicate solution to the ground are carried out more than once.
12. A method according to claim 10, wherein the body of water is a lake or Sgdam.
13. A method according to any one of the preceding claims, wherein the step •of applying a water soluble calcium salt to the ground is accompanied by the application of a weak cementitious solution.
14. A method according to claim 13, wherein the weak cementitious solution is applied to dry broken or friable soil to enhance the bonding of the soil particles
15. A method according to any one of the preceding claims, wherein the o lwater soluble calcium salt and the aquetus silicate solutione coapplied to the volume of ground containing contaminants such that the volume of ground is substantially impervious to water and entraps the contaminants. •co*
16. A method according to claim 15, wherein the water soluble calcium salt :and the aqueous silicate solution are applied at repeated intervals and at closely adjacent positions so as to entrap the contaminants to a desired area of the volume of ground
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| AU35330/97A AU732848B2 (en) | 1996-07-25 | 1997-07-25 | Method of ground treatment |
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| AUPO1241A AUPO124196A0 (en) | 1996-07-25 | 1996-07-25 | Method of ground treatment |
| AUPO1241 | 1996-07-25 | ||
| PCT/AU1997/000476 WO1998004649A1 (en) | 1996-07-25 | 1997-07-25 | Method of ground treatment |
| AU35330/97A AU732848B2 (en) | 1996-07-25 | 1997-07-25 | Method of ground treatment |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| AU3533097A AU3533097A (en) | 1998-02-20 |
| AU732848B2 true AU732848B2 (en) | 2001-05-03 |
Family
ID=25623240
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| AU35330/97A Ceased AU732848B2 (en) | 1996-07-25 | 1997-07-25 | Method of ground treatment |
Country Status (1)
| Country | Link |
|---|---|
| AU (1) | AU732848B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2025093768A1 (en) | 2023-11-03 | 2025-05-08 | Charles Tabatabai | Method for treating soils prone to differential settlement |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2637925A1 (en) * | 1988-10-18 | 1990-04-20 | Ass Tech Rech Indle | Process for consolidating moving soils and more particularly clay soils |
| SU1707138A1 (en) * | 1990-04-04 | 1992-01-23 | Якутский Научно-Исследовательский И Проектный Институт Алмазодобывающей Промышленности | Method of building grout curtain |
| EP0566122A2 (en) * | 1992-04-16 | 1993-10-20 | Westinghouse Electric Corporation | In-situ restoration of contaminated soils and groundwater |
-
1997
- 1997-07-25 AU AU35330/97A patent/AU732848B2/en not_active Ceased
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2637925A1 (en) * | 1988-10-18 | 1990-04-20 | Ass Tech Rech Indle | Process for consolidating moving soils and more particularly clay soils |
| SU1707138A1 (en) * | 1990-04-04 | 1992-01-23 | Якутский Научно-Исследовательский И Проектный Институт Алмазодобывающей Промышленности | Method of building grout curtain |
| EP0566122A2 (en) * | 1992-04-16 | 1993-10-20 | Westinghouse Electric Corporation | In-situ restoration of contaminated soils and groundwater |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2025093768A1 (en) | 2023-11-03 | 2025-05-08 | Charles Tabatabai | Method for treating soils prone to differential settlement |
| FR3155013A1 (en) | 2023-11-03 | 2025-05-09 | Charles Tabatabai | Process for treating soils subject to differential settlement |
Also Published As
| Publication number | Publication date |
|---|---|
| AU3533097A (en) | 1998-02-20 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US5631160A (en) | Method for in situ soil remediation | |
| US11998964B2 (en) | Methods and compositions for in situ groundwater remediation | |
| US10512957B2 (en) | Colloidal agents for aquifer and metals remediation | |
| Higgins et al. | Traditional and innovative treatment methods for Cr (VI) in soil | |
| US5810514A (en) | Method for introducing materials into a medium | |
| US20230364660A1 (en) | Control of soil contaminant mass discharge with horizontal permeable colloidal sorbent barriers | |
| KR20030087915A (en) | Method for purifying a layer of contaminated soil and apparatus | |
| Agassi et al. | Effect of powdered phosphogypsum on the infiltration rate of sodic soils | |
| US4623469A (en) | Method for rendering hazardous wastes less permeable and more resistant to leaching | |
| AU732848B2 (en) | Method of ground treatment | |
| WO1998004649A1 (en) | Method of ground treatment | |
| JP3267873B2 (en) | In situ reduction of soluble and insoluble heavy metals and organohalogen compounds by pneumatic fracturing with iron powder injection to purify contaminated soil and groundwater | |
| JPS62144747A (en) | Heavy metal adsorbent | |
| US5520482A (en) | Barrier to prevent spread of soil contamination | |
| EP0715903B1 (en) | A process for remedying an environment using microorganism and a process for treating soil | |
| JP2000093934A (en) | Treatment method for chromium oxide-containing soil | |
| KR100554684B1 (en) | Stabilization treatment method of tailings and slag | |
| CN212248388U (en) | In-situ blocking structure, blocking system and liquid drainage system | |
| EP3429745A1 (en) | Colloidal agents for aquifer and metals remediation | |
| US5814206A (en) | Passive acid tar neutralization process | |
| US5494703A (en) | Oxidation proof silicate surface coating on iron sulfides | |
| WO2002028783A3 (en) | In situ immobilization of metals within density variant bodies of water | |
| Pamukcu | Additive stabilization of petroleum contaminated soils | |
| US20040024282A1 (en) | Methods for stabilizing heavy metal containing material for disposal in saturated zone | |
| CN111848304A (en) | A kind of soil fixative and its application in soil containing heavy metal pollution |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FGA | Letters patent sealed or granted (standard patent) | ||
| MK14 | Patent ceased section 143(a) (annual fees not paid) or expired |