CN110026429B

CN110026429B - Soil pollution in-situ remediation technology

Info

Publication number: CN110026429B
Application number: CN201910483405.8A
Authority: CN
Inventors: 张平娟; 庞莹莹
Original assignee: Beijing Yizhilian Technology Co ltd
Current assignee: Cnnc East China Geology And Mineral Technology Co ltd
Priority date: 2019-06-04
Filing date: 2019-06-04
Publication date: 2021-10-15
Anticipated expiration: 2039-06-04
Also published as: CN110026429A

Abstract

The soil pollution in-situ remediation method includes the steps of leaching and removing soil pollutants through a chemical solvent, combining a leaching agent with the soil pollutants, and enabling heavy metals to form movable compounds through the effects of dissolution, desorption or chelation, and then conducting treatment after pollutant-containing wastewater and waste liquid are extracted through a vacuum tube well, wherein the pollutant-containing wastewater and the waste liquid can be guided to the vacuum tube well to be extracted through the matched arrangement of a water stop guide layer and the vacuum tube well, and the diffusion of the wastewater and the waste liquid is avoided.

Description

Soil pollution in-situ remediation technology

Technical Field

The invention relates to the field of pollution environment-friendly treatment, in particular to an in-situ remediation technology for soil pollution.

Background

With the settlement of atmospheric pollutants, the discharge of industrial wastewater and domestic sewage, the stacking of industrial solid waste and municipal waste, and the excessive use of pesticides and chemical fertilizers, the pollution problem becomes more and more serious when soil is used as a final carrier of most pollutants. Soil pollution affects human living environment, can also cause crop pollution, yield reduction and quality reduction, not only causes direct economic loss, but also enters human bodies through food chains and harms human health.

In soil pollution, heavy metal pollutants generally have strong biotoxicity, are accumulated for a long time once entering the soil environment and are difficult to remove, not only influence the ecological safety of the surrounding environment, but also seriously threaten the human health and food safety through direct contact, a food chain and other approaches. Therefore, the treatment of the heavy metal pollution of the soil becomes an environmental problem to be solved urgently. In-situ remediation is the primary choice in non-point source heavy metal pollution treatment due to the superiority in operation and cost.

In-situ leaching technology, a chemical solvent is used for leaching and removing soil pollutants, the leaching agent is combined with the soil pollutants, heavy metals form a movable compound through the actions of dissolution, desorption or chelation, and the like, and then wastewater and waste liquid containing the pollutants are treated. In the in-situ leaching remediation of soil, in order to avoid the influence of pollution diffusion in the remediation process, an underground water extraction method is usually adopted to extract underground water and polluted liquid together for post-treatment, but a large amount of sewage needs to be treated, and the process is complex. In the prior art, the invention of cn201410659581.x provides a horizontal water-stopping layer structure for contaminated soil remediation and a method thereof, wherein a filling hole is formed at the bottom of a contaminated soil source, and a water-stopping layer is formed after grouting, so that the extraction of underground water by an extraction well is avoided, and the sewage treatment capacity can be reduced. However, the distance between the extraction well and the survey well is long, the leacheate may diffuse out of the treatment area from the side of the survey well along the water stop layer, in order to avoid sewage leakage, the extraction well needs to be arranged in the middle or the extraction pressure of the extraction well needs to be increased, the engineering capacity is increased, or part of the underground water is extracted, so that the sewage treatment capacity is increased.

Disclosure of Invention

The invention provides an in-situ soil pollution remediation method, which can solve the problems in the prior art.

As an aspect of the present invention, there is provided a soil pollution in-situ remediation method, comprising: (1) determining the boundary and depth of the polluted soil needing to be repaired; (2) according to the soil restoration depth, arranging a first exploration well on one side outside the soil boundary; (3) arranging a second exploration well on the other side outside the soil boundary, wherein the depth of the second exploration well is greater than that of the first exploration well; (4) a first filling hole is formed in the bottom of the first exploration well downwards along the direction of the polluted soil, and a second filling hole is formed in the bottom of the second exploration well upwards along the direction of the polluted soil; enabling the first pouring hole and the second pouring hole to intersect at the central position of the soil to be repaired; (5) arranging a vertical third pouring hole at a position close to the second surveying well in the soil boundary; (6) grouting the first pouring hole and the second pouring hole; (7) grouting the third grouting hole, wherein the grouting depth is from the bottom of the second exploration well to the bottom of the first exploration well; (8) arranging a plurality of injection pipe wells along the boundary close to the first survey well in the direction of the second survey well; (9) arranging a vacuum pipe well in a repair boundary close to the second exploration well, wherein the depth of the vacuum pipe well is greater than that of the liquid injection pipe well; (10) injecting a repairing agent into the liquid injection pipe well, and starting a vacuum system to pump water into each vacuum pipe well; and repeating the steps until the water and soil in the polluted area reach the standard, and finishing the restoration.

Preferably, the depth of the vacuum tube well is equal to the depth of the second survey well.

Preferably, the depth of the first survey well is equal to the depth of the contaminated soil requiring remediation.

Preferably, the injection pipe well is used for injecting a remediation agent into the contaminated soil.

Preferably, the grouting slurry may be a cement and water glass two-fluid slurry.

Drawings

FIG. 1 is a schematic structural view of in situ remediation of soil contamination according to an embodiment of the present invention.

Detailed Description

In order to more clearly illustrate the technical solutions of the present invention, the present invention will be briefly described below by using embodiments, and it is obvious that the following description is only one embodiment of the present invention, and for those skilled in the art, other technical solutions can be obtained according to the embodiments without inventive labor, and also fall within the disclosure of the present invention.

The steps of the soil pollution in-situ remediation method according to the embodiment of the invention are described below with reference to fig. 1; (1) the need to repair the contaminated soil boundary is determined, as well as the depth h of the contaminated soil within the soil layer 2 above the aquifer 1, which is less than the depth of the soil layer 2. (2) A first exploration well 3 is arranged on one side outside the soil boundary, and the depth of the first exploration well 3 is equal to the depth h of the polluted soil needing to be repaired. (3) A second survey well 4 is provided outside the soil boundary opposite the first survey well 3, the depth of the second survey well 4 being greater than the depth of the first survey well 3 and less than the depth of the soil layer. (4) A first pouring hole 31 is formed downwards along the direction of the polluted soil at the bottom of the first exploration well 3, and a second pouring hole 41 is formed upwards along the direction of the polluted soil at the bottom of the second exploration well 4; the first pouring hole 31 and the second pouring hole 41 are intersected at the central position of the soil to be repaired; (5) arranging a vertical third pouring hole 5 at a position close to the second exploration well 4 in the soil boundary, wherein the depth of the third pouring hole 5 is close to that of the second exploration well 4; (6) and (3) inserting a pouring pipeline into the first pouring hole 31 and the second pouring hole 41, and grouting the first pouring hole 31 and the second pouring hole 41, wherein grouting slurry can be cement and water glass double-liquid slurry to form an inclined water stop guide layer. (7) And grouting the third grouting hole 5, wherein the grouting depth is from the bottom of the second exploration well 4 to the bottom of the first exploration well 3, so that a vertical water stop wall positioned at one layer of the vacuum tube well is formed. (8) A plurality of liquid injection pipe wells 6 are arranged along the boundary close to the first exploration well 3 in the direction of the second exploration well 4 and are used for injecting a remediation agent into the polluted soil, wherein the remediation agent can be an eluent which can be combined with heavy metal pollutants in the soil and form a migratable compound after dissolution, desorption or chelation; the depth of the liquid injection tube well 6 is equal to the depth h of the polluted soil, and liquid outlets with different depths are arranged on the side wall of the liquid injection tube well and are used for outputting the repairing medicament; (9) arranging a vacuum pipe well 7 in the restoration boundary close to the second exploration well 4, wherein the depth of the vacuum pipe well 7 is greater than that of the liquid injection pipe well and is close to the top of the water stop guide layer; (10) injecting a repairing agent into the liquid injection pipe well 6, and starting a vacuum system to pump water into the vacuum pipe well 7; and (4) treating heavy metal pollutants by the pumped sewage through a sewage treatment system, and repeating the steps until the water and soil in the polluted area reach the standard, thereby completing remediation.

Through the embodiment of the invention, the waste water containing pollutants in the soil is guided to the vicinity of the vacuum tube well, and the leakage of the waste water is avoided through the vertical water stop wall, so that the waste water in the soil pollution can be completely extracted without increasing the number of the vacuum tube wells or increasing the suction pressure of the vacuum tube wells.

The invention has been described herein with reference to specific exemplary embodiments thereof. It will be apparent to those skilled in the art that appropriate substitutions or modifications may be made without departing from the scope of the invention. The exemplary embodiments are merely illustrative, and not restrictive of the scope of the invention, which is defined by the appended claims.

Claims

1. An in-situ soil pollution remediation method comprises the following steps: (1) determining the boundary and depth of the polluted soil needing to be repaired; (2) according to the soil restoration depth, arranging a first exploration well on one side outside the soil boundary; (3) arranging a second exploration well on the other side outside the soil boundary, wherein the depth of the second exploration well is greater than that of the first exploration well; (4) a first filling hole is formed in the bottom of the first exploration well downwards along the direction of the polluted soil, and a second filling hole is formed in the bottom of the second exploration well upwards along the direction of the polluted soil; enabling the first pouring hole and the second pouring hole to intersect at the central position of the soil to be repaired; (5) arranging a vertical third pouring hole at a position close to the second surveying well in the soil boundary; (6) grouting the first pouring hole and the second pouring hole; (7) grouting the third grouting hole, wherein the grouting depth is from the bottom of the second exploration well to the bottom of the first exploration well; (8) positioning a plurality of injection tubing wells along a boundary adjacent the first survey well in a direction toward the second survey well; (9) arranging a vacuum pipe well in a repair boundary close to the second exploration well, wherein the depth of the vacuum pipe well is greater than that of the liquid injection pipe well; (10) injecting a repairing agent into the liquid injection pipe well, and starting a vacuum system to pump water into each vacuum pipe well; and repeating the steps until the water and soil in the polluted area reach the standard, and finishing the restoration.

2. The in situ remediation method of soil contamination of claim 1, wherein: the depth of the vacuum tube well is equal to the depth of the second survey well.

3. The in situ remediation method of soil contamination of claim 1, wherein: the depth of the first survey well is equal to the depth of the contaminated soil that needs remediation.

4. The in situ remediation method of soil contamination of claim 1, wherein: the liquid injection pipe well is used for injecting a repairing agent into the polluted soil.

5. The in situ remediation method of soil contamination of claim 1, wherein: the grouting slurry is cement and water glass double-liquid slurry.