CN113857225B - Soil restoration method for extraction after solidification of injected liquid - Google Patents

Soil restoration method for extraction after solidification of injected liquid Download PDF

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CN113857225B
CN113857225B CN202010618433.9A CN202010618433A CN113857225B CN 113857225 B CN113857225 B CN 113857225B CN 202010618433 A CN202010618433 A CN 202010618433A CN 113857225 B CN113857225 B CN 113857225B
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injection
extraction
soil
soil remediation
well
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CN113857225A (en
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魏昕
郦和生
孟凡宁
王岽
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Sinopec Beijing Research Institute of Chemical Industry
China Petroleum and Chemical Corp
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Sinopec Beijing Research Institute of Chemical Industry
China Petroleum and Chemical Corp
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B09—DISPOSAL OF SOLID WASTE; RECLAMATION OF CONTAMINATED SOIL
    • B09C—RECLAMATION OF CONTAMINATED SOIL
    • B09C1/00—Reclamation of contaminated soil
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B09—DISPOSAL OF SOLID WASTE; RECLAMATION OF CONTAMINATED SOIL
    • B09C—RECLAMATION OF CONTAMINATED SOIL
    • B09C1/00—Reclamation of contaminated soil
    • B09C1/06—Reclamation of contaminated soil thermally
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B09—DISPOSAL OF SOLID WASTE; RECLAMATION OF CONTAMINATED SOIL
    • B09C—RECLAMATION OF CONTAMINATED SOIL
    • B09C1/00—Reclamation of contaminated soil
    • B09C1/08—Reclamation of contaminated soil chemically
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B09—DISPOSAL OF SOLID WASTE; RECLAMATION OF CONTAMINATED SOIL
    • B09C—RECLAMATION OF CONTAMINATED SOIL
    • B09C1/00—Reclamation of contaminated soil
    • B09C1/10—Reclamation of contaminated soil microbiologically, biologically or by using enzymes
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B09—DISPOSAL OF SOLID WASTE; RECLAMATION OF CONTAMINATED SOIL
    • B09C—RECLAMATION OF CONTAMINATED SOIL
    • B09C2101/00—In situ

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  • Life Sciences & Earth Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Soil Sciences (AREA)
  • Environmental & Geological Engineering (AREA)
  • Health & Medical Sciences (AREA)
  • Thermal Sciences (AREA)
  • Physics & Mathematics (AREA)
  • Biomedical Technology (AREA)
  • Biotechnology (AREA)
  • General Health & Medical Sciences (AREA)
  • Microbiology (AREA)
  • Molecular Biology (AREA)
  • Mycology (AREA)
  • Processing Of Solid Wastes (AREA)

Abstract

The invention relates to the field of soil remediation, and discloses a soil remediation method for extracting after liquid injection solidification, which comprises the following steps: 1) Drilling an extraction well on the polluted soil, and drilling an injection port on the wall of the extraction well; 2) Injecting injection liquid into the soil through an injection opening, wherein the injection liquid is a substance which can form an extraction channel in the soil after solidification; 3) Performing in-situ extraction on the extraction well to obtain an extract; wherein the extraction channel is capable of adsorbing and/or transporting organic contaminants within the contaminated soil. The soil remediation method can be used for remediating the polluted soil for a long time and efficiently, and meanwhile, the soil remediation method does not cause secondary pollution and meets the environmental protection requirement.

Description

Soil restoration method for extraction after solidification of injected liquid
Technical Field
The invention relates to the field of soil remediation, in particular to a soil remediation method for extracting after liquid injection solidification.
Background
Along with the improvement of national economic level and the transformation of production concept, the environmental protection index of petrochemical enterprises such as oil refining chemical industry is continuously improved. Petroleum refining enterprises have the unavoidable situation that part of crude oil and finished oil directly or indirectly flow into soil. In addition, a large number of chemical enterprises also have the risk of pollution of substances to be crosslinked in the soil caused by leakage of chemicals and inflow of the chemicals into the soil. The substances to be crosslinked pollute the underground water along with the transfer of soil moisture. Crude oil, finished oil, other organic chemicals and the like have profound pollution to soil, and can directly cause death of animals, plants and microorganisms.
At present, an in-situ extraction method is a relatively practical repairing method aiming at the pollution of substances to be crosslinked in soil. The common in-situ extraction method is to punch a multi-hole longitudinal extraction well above the polluted soil, extract the polluted soil at an extraction well head in a negative pressure mode, promote organic pollutants in the soil to be gasified from the soil, and then enter a subsequent waste gas treatment device in a gaseous form for harmless treatment.
However, the air permeability of the contaminated soil tends to be reduced, and especially the land block contaminated by oil products such as heavy crude oil is severely hardened, well construction and then direct in-situ extraction are mainly adopted in the prior art, but the soil range in which each well can act is limited, and the effect is generally poor. There are also methods of high temperature dry cracking and then fracturing, but the soil is hardened again during extraction or the gap is closed during extraction, resulting in poor extraction effect. This results in the often unsatisfactory repair effect of conventional in situ extraction techniques.
Disclosure of Invention
The invention aims to solve the problem of unsatisfactory extraction effect of in-situ extraction in the prior art.
In order to achieve the above object, the present invention provides a soil restoration method for extraction after solidification by injection, the soil restoration method comprising:
1) Drilling an extraction well on the polluted soil, and drilling an injection port on the wall of the extraction well;
2) Injecting injection liquid into the soil through an injection opening, wherein the injection liquid is a substance which can form an extraction channel in the soil after solidification;
3) Performing in-situ extraction on the extraction well to obtain an extract;
wherein the extraction channel is capable of adsorbing and/or transporting organic contaminants within the contaminated soil.
Preferably, curing comprises physical crosslinking and/or chemical crosslinking.
Preferably, the injection liquid satisfies the following condition: the viscosity is 100 pa-10000 pa, preferably 500 pa-2000 pa.
Preferably, the substance A formed after the injection is solidified is at least one selected from silicone rubber, guanidine gum, polyacrylic acid and polyurethane, preferably silicone rubber prepared by cross-linking hydroxyl silicone oil and/or room temperature solidified silicone rubber. Preferably, before step 2), the soil remediation method further comprises: and pre-crosslinking the substance to be crosslinked and the auxiliary agent to obtain the injection.
Preferably, the auxiliary agent contains a crosslinking agent, a catalyst and a solvent.
Preferably, the substance to be crosslinked is selected from hydroxyl silicone oil and/or methyl vinyl silicone rubber, the catalyst is dibutyl tin dilaurate, the crosslinking agent is ethyl orthosilicate, and the solvent is selected from at least one of n-hexane, toluene and n-heptane.
Preferably, the weight ratio of the substance to be crosslinked, the crosslinking agent, the catalyst and the solvent is 100: (10-150): (0.1-10): (50-300).
Preferably, the pre-crosslinking satisfies the following conditions: the temperature is-20 to 120 ℃, the time is 2 to 120 hours, more preferably 24 to 48 hours.
Preferably, the injection liquid is injected at a pressure of 0.01Mpa-100Mpa, preferably 1.0Mpa-2.0Mpa.
Preferably, the injection amount of the injection liquid per 100 cubic meters of contaminated soil is 1 to 1000L, preferably 10 to 200L.
Preferably, the injection depth of the injection liquid is 5-500m, preferably 5-20m.
Preferably, the injection amount of each injection port is 20-30L.
Preferably, the diameter of the injection port is 0.1-20mm, preferably 1-5mm.
Preferably, in the contaminated area in the contaminated soil, a set of injection ports, each set comprising 3-6 injection ports, is arranged on the extraction well at intervals of 8-15 meters along the extension direction of the extraction well.
Preferably, the injection ports in each set of injection ports are evenly distributed along the circumference of the wall of the extraction well.
Preferably, the injection direction of the injection liquid is perpendicular to the wall of the extraction well.
Preferably, the curing time is from 200min to 100h, preferably from 2 to 24h.
Preferably, the injection liquid further contains at least one of a filler and an oxidizing agent.
Preferably, the filler is selected from at least one of gravel, activated carbon, molecular sieves, and zeolite.
Preferably, the oxidizing agent is selected from potassium permanganate and/or potassium dichromate.
Preferably, step 2) further comprises: the injection device is preferably a nozzle, and is provided on the injection port.
Preferably, step 2) further comprises: firstly, preparing injection liquid in a preparation device, and then driving the injection liquid to be injected into soil through an injection liquid pipeline by a conveying device.
Preferably, the end of the injection liquid conduit extends into the injection port.
Preferably, the delivery device is a pump.
Preferably, the pressure of the in situ extraction is-0.001 MPa to-0.1 MPa, preferably-0.08 MPa to-0.095 MPa.
Preferably, the in situ extraction is carried out for a period of 20 to 1000 hours, preferably 24 to 48 hours.
Preferably, the in situ extraction is done in one go or batch.
Preferably, the distance between the centers of the top ends of two adjacent extraction wells is 3-5m.
Preferably, the extraction well comprises at least a grade 2 well, and the step of drilling the extraction well in step 1) comprises: and drilling a next-stage well from the well wall of the previous stage.
Preferably, the fracking well mechanism comprises a primary well and a secondary well, and the step of drilling the extraction well in step 1) comprises: and drilling a secondary well from the middle lower part of the primary well.
Preferably, the method further comprises: the extract is subjected to a post-treatment.
Preferably, the post-treatment comprises: and separating the extract to obtain organic pollutant gas, sediment and wastewater, and performing innocent treatment on the organic pollutant gas.
Preferably, the post-treatment comprises: and (3) carrying out three-phase separation on the extract in an extract treatment device after washing and cooling to obtain organic pollutant gas, sediment and wastewater, and then collecting the organic pollutant gas into an exhaust gas treatment device for harmless treatment.
Preferably, the innocuous treatment is selected from at least one of absorption, adsorption, water washing, alkali washing, membrane separation, catalytic oxidation, regenerative combustion, direct combustion, plasma technology treatment, chemical oxidation and microbial treatment.
According to the technical scheme, firstly, an extraction well is drilled on polluted soil, then injection liquid is injected into the soil through an injection opening, and the injection liquid can fracture the soil in the injection process, so that an injection liquid channel is formed in the soil; the injection liquid fills the injection liquid channel, and after solidification, the injection liquid can form an extraction channel. The extraction channel is a product obtained by solidifying organic matters, has oleophilic and hydrophobic properties, so that organic pollutants in polluted soil can be adsorbed and/or transported, and meanwhile, the contact area between the extraction well and the soil can be indirectly increased, and the air permeability of the soil can be also improved.
Thus, during the in situ extraction process, organic contaminants are desorbed from the soil particles under the action of the negative pressure to form a gas phase. On one hand, the injection liquid is used for carrying out structural optimization on the soil polluted by the organic matters, so that a polymer network structure can be formed, a channel for capturing and transporting the pollutants is obtained, the improvement of the air permeability of the soil is promoted, the transfer effect of the organic pollutants in the air phase in the soil can be accelerated, and the extraction range and the extraction efficiency of an extraction well are greatly improved; on the other hand, the extraction channel has the functions of adsorbing and transferring organic pollutants, and the quantity and the rate of the organic pollutants entering the extraction well are further improved by taking the organic pollutants as a medium and a channel; meanwhile, the performance of the extraction channel is stable in soil, harmful substances are not released to the soil, and the extraction channel can be repeatedly utilized in the soil for a long time, so that the extraction can be performed for a long time and multiple times on the same soil area; after the single extraction is completed, the extraction channel can continuously adsorb and fix organic pollutants in the soil, and the soil is subjected to long-time deep treatment, so that the pollutants are prevented from penetrating into the underground water. The method adopts an in-situ extraction technology, has small damage to soil and low cost, and can repair the polluted soil in a larger range by combining a single extraction well with gas phase fracturing.
In conclusion, the soil remediation method provided by the invention can be used for remediating the polluted soil for a long time and efficiently, and meanwhile, the soil remediation method can not cause secondary pollution and meets the environmental protection requirement.
Drawings
FIG. 1 is a schematic operation diagram of steps 1) and 2) in the soil remediation method for extraction after solidification of injected liquid;
fig. 2 is a schematic operation diagram of step 3) in the soil remediation method for extraction after solidification of the injection liquid provided by the invention.
Description of the reference numerals
1. Extraction well 2 and preparation device
3. Conveying device 4 and injection liquid pipeline
5. Injection device 6, extraction channel
7. Extract treatment device 8 and contaminated soil
Detailed Description
The endpoints and any values of the ranges disclosed herein are not limited to the precise range or value, and are understood to encompass values approaching those ranges or values. For numerical ranges, one or more new numerical ranges can be obtained in combination with each other between the endpoints of each range, between the endpoint of each range and the individual point value, and between the individual point value, and are to be considered as specifically disclosed herein.
In the present invention, unless otherwise indicated, the use of orientation words such as "top, bottom, upper, lower" and the like included in the terms merely represents the orientation of the terms in the normal use state or is commonly known by those skilled in the art, and should not be construed as limiting the terms.
The invention provides a soil restoration method for extraction after injection solidification, which is shown in figures 1-2 and comprises the following steps:
1) Drilling an extraction well 1 on polluted soil 8, and drilling an injection port on the wall of the extraction well 1;
2) Injecting injection liquid into the soil through an injection opening, wherein the injection liquid is a substance which can form an extraction channel 6 in the soil after solidification;
3) Performing in-situ extraction on the extraction well 1 to obtain an extract;
wherein the extraction channel 6 is capable of adsorbing and/or transporting organic contaminants within the contaminated soil 8.
In the above soil remediation method, in order to further enhance the effect of solidification and thereby enhance the effect of adsorption and/or transport of organic contaminants by the extraction channel 6, it is preferable that the solidification includes physical crosslinking and/or chemical crosslinking.
In the above soil remediation method, in view of the flow property of the injection liquid, and at the same time, in order to enhance the effect of the extraction channel 6 for adsorbing and/or transporting organic pollutants, it is preferable that the injection liquid satisfies the following conditions: the viscosity is 100 pa-10000 pa, preferably 500 pa-1000 pa.
In the above-described soil remediation method, in view of the flowability of the injection liquid, and in order to enhance the effect of the extraction channel 6 in adsorbing and/or transporting organic contaminants, it is preferable that the substance a formed after solidification of the injection liquid is selected from at least one of silicone rubber, guanidine gum, polyacrylic acid and polyurethane, preferably silicone rubber produced by crosslinking of hydroxy silicone oil and/or room temperature curing silicone rubber.
In the present invention, in order to ensure stability of the performance of the injection liquid and to enhance the effect of the extraction channel 6 in adsorbing and/or transporting organic pollutants, preferably, before step 2), the soil remediation method further comprises: and pre-crosslinking the substance to be crosslinked and the auxiliary agent to obtain the injection. In order to further provide the effect of adsorbing and/or transporting organic pollutants by the extraction channel 6, preferably, the auxiliary agent contains a cross-linking agent, a catalyst and a solvent; more preferably, the substance to be crosslinked is selected from at least one of a mixture of dimethylsiloxane and vinyl siloxane (forming methyl vinyl silicone rubber), hydroxy silicone oil, and the catalyst is selected from dibutyltin dilaurate; the cross-linking agent is selected from tetraethoxysilane, and the solvent is selected from at least one of n-hexane, toluene and n-heptane.
In the above embodiment, in order to further enhance the effect of the extraction channel 6 on adsorbing and/or transporting organic contaminants, it is preferable that the weight ratio of the substance to be crosslinked, the crosslinking agent, the catalyst and the solvent is 100: (10-150): (0.1-10): (50-300).
In the above embodiment, in order to further enhance the effect of the extraction channel 6 on adsorbing and/or transporting organic contaminants, it is preferable that the pre-crosslinking satisfies the following conditions: the temperature is-20 to 120 ℃, the time is 2 to 120 hours, more preferably 24 to 48 hours.
In the above embodiment, in order to enhance the rate and effect of the injection liquid into the soil and further enhance the effect of the extraction channel 6 for adsorbing and/or transporting the organic contaminant, the injection liquid is preferably injected at a pressure of 0.01Mpa to 100Mpa, preferably 1.0Mpa to 2.0Mpa.
In the above embodiment, in order to increase the amount of the injection liquid into the soil and thus to increase the effect of the in-situ extraction, the injection amount of the injection liquid per 100 cubic meters of the contaminated soil 8 is preferably 1 to 1000L, and preferably 10 to 200L.
In the above embodiment, in order to further enhance the effect of in-situ extraction, the injection depth of the injection liquid is preferably 5 to 500m, and more preferably 5 to 20m.
In the above embodiment, in order to increase the injection amount of the injection liquid of the single injection port, thereby further improving the effect of the in-situ extraction, the injection port preferably has a diameter of 5 to 20mm, and more preferably 1 to 5mm.
In the present invention, in order to further optimize the density of the extraction channel 6 in the soil and further enhance the in-situ extraction effect, it is preferable that a set of injection ports, each set including 3 to 6 injection ports, are provided on the extraction well 1 every 8 to 15 meters along the extension direction of the extraction well 1 in the contaminated area in the contaminated soil 8. In which organic contaminants are deposited in the soil and in the partially contaminated soil 8, there is no organic contaminant in the upper region, so that, in order to further enhance the effect of adsorbing and/or transporting organic contaminants by the extraction channel 6, only injection ports are provided in the region where organic contaminants are present.
In the above embodiment, in order to uniformly distribute the extraction channels 6 in the contaminated soil 8 and thereby enhance the in-situ extraction effect, it is preferred that the injection ports of each set of injection ports are uniformly distributed along the circumference of the wall of the extraction well 1.
In the present invention, in order to further improve the accuracy of the injection liquid into the injection port and the injection efficiency, it is preferable that the injection direction of the injection liquid is perpendicular to the wall of the extraction well 1.
In the invention, in order to ensure that the injection solution is thoroughly solidified in the soil and further improve the effect of in-situ extraction, the solidification time is preferably 200min-100h, and preferably 2-24h.
In the present invention, in order to further enhance the effect of the extraction channel 6 on the treatment of organic contaminants in the soil, it is preferable that the injection liquid further contains at least one of a filler and an oxidizing agent. The particles in the filler have supporting effect on the extraction channel 6 and cracks at the periphery of the extraction channel 6, so that collapse of the cracks is avoided, and the transmission effect of organic pollutants in the extraction channel 6 and the cracks can be improved in the in-situ extraction process. The oxidant can oxidize the gas-phase organic pollutants into harmless small molecules such as carbon dioxide, water and the like, so that the auxiliary agents such as the filler, the oxidant and the like have remarkable positive effects on the removal of the organic pollutants. In addition, the addition sequence of the auxiliary agents such as the filler, the oxidant and the like can be added in the forming process of the injection liquid (such as the pre-crosslinking process), and can also be added into the injection liquid after the injection liquid is formed, because the auxiliary agents such as the filler, the oxidant and the like do not participate in the crosslinking of the substances to be crosslinked.
In the present invention, in order to further improve the effect of soil remediation, it is preferable that at least one of filler gravel, activated carbon, molecular sieve, and zeolite.
In the present invention, in order to further enhance the effect of soil remediation, preferably, the oxidizing agent is selected from potassium permanganate and/or potassium dichromate.
In the above embodiment, in order to further improve the effect of filling the soil cracks with the injection liquid, preferably, the step 2) further includes: the injection device 5 is arranged on the injection port, the injection device 5 preferably being a nozzle.
In the above embodiment, in order to improve the efficiency of the injection liquid into the soil, preferably, the step 2) further includes: firstly, the injection liquid is prepared in the preparation device 2, and then the injection liquid is driven by the conveying device 3 to be injected into the soil through the injection liquid pipeline 4. In order to further ensure that the injection liquid enters the soil fracture accurately, it is preferred that the end of the injection liquid conduit 4 extends into the injection port, more preferably that the delivery device 3 is a pump.
In the present invention, in order to further enhance the effect of the in-situ extraction, the pressure of the in-situ extraction is preferably-0.001 Mpa to-0.1 Mpa, and preferably-0.08 Mpa to-0.095 Mpa.
In the present invention, in order to further enhance the effect of the in-situ extraction, it is preferable that the time of the in-situ extraction is 20 to 1000 hours, preferably 24 to 48 hours.
In the present invention, in order to facilitate control of the progress of the operation, the in-situ extraction is preferably performed at one time or intermittently.
In the present invention, in order to enhance the soil remediation effect, it is preferable that the distance between the centers of the tips of the adjacent two extraction wells is 3-5m.
In the present invention, in order to enhance the soil remediation effect, preferably, the extraction well 1 comprises at least 2-stage wells, and the step of drilling the extraction well 1 in step 1) comprises: drilling a next-stage well from the well wall of the previous stage; more preferably, the fracturing well unit comprises a primary well and a secondary well, and the step of drilling the extraction well 1 in step 1) comprises: and drilling a secondary well from the middle lower part of the primary well.
In the present invention, in order to prevent the extracted organic pollutants from causing secondary pollution to the environment, the method preferably further comprises: post-treating the extract; in order to further render harmless organic contaminants, the post-treatment preferably comprises: separating the extract to obtain organic pollutant gas, sediment and wastewater, and performing innocent treatment on the organic pollutant gas; more preferably, the post-treatment comprises: the extract is subjected to water washing and cooling, and is subjected to three-phase separation in an extract treatment device 7 to obtain organic pollutant gas, sediment and wastewater, and then the organic pollutant gas is collected into an exhaust gas treatment device for harmless treatment.
Preferably, the innocuous treatment is selected from at least one of absorption, adsorption, water washing, alkali washing, membrane separation, catalytic oxidation, regenerative combustion, direct combustion, plasma technology treatment, chemical oxidation and microbial treatment.
The invention will be described in detail below by way of examples. In the examples below, the organic contaminant content parameter is measured by a method of gas chromatography combined with mass spectrometry after solvent extraction.
Example 1
The technology of the invention is adopted for treatment after the soil pollution of crude oil tank areas of certain refineries. The soil layer depth of the soil pollution site is 20-100 meters, and the soil is seriously hardened due to the penetration of crude oil for many years, so that the air permeability is very poor. The total content of organic pollutants in the soil is 2.9Kg/m 3 The method comprises the steps of carrying out a first treatment on the surface of the Organic contaminants consist of 1:2 toluene and carbon tetrachloride.
The soil remediation scheme and the treatment effect are as follows:
(1) Drilling an extraction well: as shown in fig. 1, 20 vertical extraction wells 1 are drilled in the area of polluted soil, and the distance between the centers of two adjacent wells is 4m; and drilling injection ports on the wall of the extraction well 1, setting a group of injection ports every 10 meters at the depth of the extraction well 1 of 20-100m, wherein each group of injection ports is 4, and the injection ports in each group of injection ports are uniformly distributed along the circumference of the extraction well wall.
(2) Preparing injection: the preparation weight ratio in the preparation device 2 is 100:80:5:200, a cross-linking agent (ethyl orthosilicate), a catalyst (dibutyl tin dilaurate) and a solvent (n-hexane, toluene and n-heptane), and after uniformly stirring, pre-crosslinking for 24 hours at 20 ℃ to obtain a pre-crosslinked liquid (viscosity is 1050Pa.s).
(3) Injecting a pre-crosslinking liquid: as shown in fig. 1, the conveying device 3 injects the pre-crosslinked liquid into the injection mechanism 5 of the injection port through the injection liquid pipe 4 in a direction perpendicular to the wall of the longitudinal extraction well, the injection amount of the injection liquid per 100 cubic meters of contaminated soil is 200L, and the injection pressure is 20Mpa.
(4) Crosslinking of the injection solution: the extraction channels 6 were formed by curing for 48 hours.
(5) Organic extraction: as shown in FIG. 2, the wellhead of each longitudinal extraction well is operated by adopting a closed negative pressure, the pressure is kept at-0.09 Mpa, the extraction time is 200 hours, the organic matters in the soil are accelerated to volatilize, gasify and extract to obtain an extraction mixture, and the extraction mixture is subjected to three-phase separation in an extract treatment device to obtain organic pollutant gas.
(6) Waste gas treatment: organic pollutant gas is subjected to innocent treatment by adopting the technologies of water washing, alkali washing, membrane separation and low-temperature catalytic oxidation.
Through the above process, the total content of organic pollutants in the soil is reduced to 0.2g/m 3 The removal rate of the extraction operation is up to more than 99.9 percent. In the treatment process, the waste gas is subjected to innocent treatment, and the concentration of the tail gas is always lower than 20mg/m 3 。
Example 2
The embodiment is used for repairing the soil polluted by gasoline and diesel oil of a gas station. The soil layer depth of the soil pollution site is 10-30 m, the pollution range is 200 square meters, and the polluted soil volume is about 4000m 3 The soil is polluted by the sudden leakage of the gasoline of the gas station, the pumping is advanced, and the total content of organic pollutants in the soil is 300g/m 3 The organic pollutant is diesel oil.
The soil is restored by the following scheme and treatment effect:
1) Drilling an extraction well: an extraction well is drilled vertically in the center of the contaminated soil area. And drilling a secondary extraction well in the horizontal direction at the depth of 20 meters of the drilled primary extraction well.
The distance between the circle centers of two adjacent primary extraction wells is 3m; and drilling injection openings on the walls of the primary extraction well and the secondary extraction well, and setting a group of injection openings every 10 meters at the depth of 20-100m of the primary extraction well and the secondary extraction well, wherein each group of injection openings is 4, and the injection openings in each group of injection openings are uniformly distributed along the circumferential direction of the extraction well wall, and the total number of the injection openings is 100.
2) Preparing injection: the preparation weight ratio in the preparation device 2 is 100:10:0.1:50, a cross-linking agent (ethyl orthosilicate), a catalyst (dibutyl tin dilaurate) and a solvent (n-hexane, toluene and n-heptane), and after uniformly stirring, pre-crosslinking for 24 hours at 0 ℃ to obtain a pre-crosslinked liquid (the viscosity is 520 Pa.s).
3) Injecting a pre-crosslinking liquid: the pre-crosslinked liquid was injected into the injection port in a direction perpendicular to the wall of the longitudinal extraction well, the injection amount of the injection liquid per 100 cubic meters of contaminated soil was 10L, and the injection pressure was 20MPa.
4) Crosslinking of the injection solution: after 5 hours of curing, extraction channels were formed after curing of the polydimethylsiloxane. The channel has good compatibility with gasoline components, can adsorb organic matters in soil into the channel, and can form organic matter transportation when diffusion driving force exists.
5) Organic extraction: and (3) adopting closed negative pressure operation at the wellhead of the primary extraction well, wherein the negative pressure is kept at-0.09 Mpa, the extraction time is 500 hours, the diffusion and the transportation of the organic matters in the silicon rubber extraction channel are promoted, and the organic matters in the soil are accelerated to be extracted.
6) Waste gas treatment: the extracted waste gas is recycled and subjected to innocent treatment by adopting a condensation and membrane separation combined adsorption method.
Through the above process, the total content of organic pollutants in the soil is reduced to 0.01g/m 3 The removal rate of the extraction operation is up to more than 99.99 percent. In the treatment process, the waste gas is subjected to innocent treatment, and the concentration of the tail gas is always lower than 20mg/m 3 And about 1 ton of leaked diesel oil is recovered by condensation and membrane separation processes.
Example 3
This example caused leakage of toluene tank in chemical plantIs a contaminated soil remediation process. The soil layer depth of the soil pollution site is 30 meters, the pollution range is 100 square meters, the soil is polluted by the leakage of a toluene tank in a chemical plant, the pumping is advanced, and the total content of organic pollutants in the soil is 2.6Kg/m 3 。
The soil is restored by the following scheme and treatment effect:
1) Drilling an extraction well: an extraction well is drilled vertically in the center of the contaminated soil area. And drilling a secondary extraction well in the horizontal direction at the depth of 20 meters of the drilled primary extraction well.
The distance between the circle centers of two adjacent primary extraction wells is 5m; and drilling injection openings on the walls of the primary extraction well and the secondary extraction well, and setting a group of injection openings every 10 meters at the depth of 20-100m of the primary extraction well and the secondary extraction well, wherein each group of injection openings is 4, and the injection openings in each group of injection openings are uniformly distributed along the circumference of the extraction well wall.
3) Preparing injection: the preparation weight ratio in the preparation device 2 is 100:150:10:300, a cross-linking agent (tetraethoxysilane), a catalyst (dibutyl tin dilaurate) and a solvent (n-hexane, toluene and n-heptane), and after uniformly stirring, pre-crosslinking for 48 hours at 80 ℃ to obtain a pre-crosslinked liquid (viscosity of 2000 Pa.s).
4) Injecting a pre-crosslinking liquid: injecting the pre-crosslinked liquid into the injection port in a direction perpendicular to the wall of the longitudinal extraction well, wherein the injection amount of the injection liquid is 10-20L per 100 cubic meters of polluted soil, and the injection pressure is 15Mpa.
5) Injection fluid crosslinking process: extraction channels were formed by 10 hours of curing. The channel has good compatibility with gasoline components, can adsorb organic matters in soil into the channel, and can form organic matter transportation when diffusion driving force exists.
6) Organic extraction: and (3) adopting closed negative pressure operation at the wellhead of the extraction well, wherein the negative pressure is kept at-0.08 Mpa, the extraction time is 500 hours, organic pollutants are promoted to diffuse into an extraction channel in the soil, and then the organic pollutants diffuse and are conveyed to the wellhead rapidly in the channel, so that toluene in the soil is extracted.
(7) Waste gas treatment: the extracted waste gas is recycled and subjected to innocent treatment by adopting a coupling method of condensation and membrane separation combined with an adsorption technology.
Through the above process, the total content of organic matters in the soil is reduced to 10g/m 3 The removal rate of the extraction operation is up to more than 99.6 percent. In the treatment process, the waste gas is subjected to innocent treatment, and the concentration of the tail gas is always 80mg/m 3 And 80% of the leaked toluene can be recovered; recovery = total weight of toluene recovered/total weight of toluene detected before extraction x 100%.
Example 4
The procedure of example 1 was followed, except that the injection liquid further contained a filler (gravel, average particle diameter: 5 mm), and the filler was used in an amount of 5L/m 3 Soil.
After the extraction was completed, the total content of contaminants was reduced to 0.15g/m 3 。
Comparative example 1
The procedure of example 1 was followed, except that the injection solution was a 2 wt% gelatin solution. After the extraction is finished, the total content of the machine pollutants is reduced to 405.5g/m 3 。
As can be seen from comparison of the comparative example 1 and the example 1, the soil restoration method provided by the invention has the advantages that the injection liquid is injected into the soil, the extraction channel is formed after solidification, the extraction channel can obviously improve the in-situ extraction effect, and the soil restoration effect is obviously improved. Meanwhile, the performance of the extraction channel is stable in soil, harmful substances are not released to the soil, and the extraction channel can be repeatedly utilized in the soil for a long time, so that the extraction can be performed on the same soil area for a long time and repeatedly.
The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited thereto. Within the scope of the technical idea of the invention, a number of simple variants of the technical solution of the invention are possible, including combinations of the individual technical features in any other suitable way, which simple variants and combinations should likewise be regarded as being disclosed by the invention, all falling within the scope of protection of the invention.

Claims (29)

1. The soil restoration method for extraction after injection solidification is characterized by comprising the following steps of:
1) Drilling an extraction well (1) on contaminated soil (8), and drilling an injection port on the wall of the extraction well (1);
2) Pre-crosslinking a substance to be crosslinked and an auxiliary agent to obtain injection; injecting the injection liquid into the soil through the injection opening, wherein the injection liquid is a substance which can form an extraction channel (6) in the soil after solidification; the auxiliary agent contains a cross-linking agent, a catalyst and a solvent;
the weight ratio of the substances to be crosslinked to the crosslinking agent to the catalyst to the solvent is 100: (10-150): (0.1-10): (50-300); the substance A formed after the injection is solidified is silicone rubber prepared by hydroxyl silicone oil crosslinking and/or room temperature solidified silicone rubber; the injection liquid meets the following conditions: viscosity is 500pa s-2000pa s;
the substance to be crosslinked is selected from the mixture of dimethyl siloxane and vinyl siloxane 、 At least one of hydroxyl silicone oil, wherein the catalyst is dibutyl tin dilaurate, the cross-linking agent is ethyl orthosilicate, and the solvent is at least one of n-hexane, toluene and n-heptane;
3) Performing in-situ extraction on the extraction well (1) to obtain an extract; the pressure of the in-situ extraction is-0.08 Mpa to-0.095 Mpa; the in-situ extraction time is 20-500h;
wherein the extraction channel (6) is capable of adsorbing and/or transporting organic contaminants within the contaminated soil (8); the injection amount of the injection liquid is 1-1000L per 100 cubic meters of the polluted soil (8);
the pre-crosslinking satisfies the following conditions: the temperature is between 20 ℃ below zero and 120 ℃ below zero for 2 to 120 hours;
the injection pressure is 0.01Mpa-100Mpa during injection;
the injection depth of the injection liquid is 5-500m.
2. The soil remediation method of claim 1 wherein the curing includes physical and/or chemical crosslinking.
3. The soil remediation method of claim 1 wherein the pre-crosslinking time is 24-48 hours.
4. The soil remediation method of claim 1 or 2 wherein the injection fluid is injected at a pressure of 1.0Mpa to 2.0Mpa.
5. Soil remediation method according to claim 1, characterized in that the injection quantity of the injection liquid per 100 cubic meters of the contaminated soil (8) is 10-200L.
6. The soil remediation method of claim 1 wherein the injection depth of the injection fluid is 5-20m.
7. A soil remediation method according to claim 1 or claim 2 wherein the injection port is 5-20mm in diameter.
8. A soil remediation method according to claim 1 or claim 2 wherein the injection port is 1-5mm in diameter.
9. A soil remediation method according to claim 1 or 2, characterized in that in the contaminated area of the contaminated soil (8) a set of injection openings is provided on the extraction well (1) at intervals of 8-15 meters along the extension direction of the extraction well (1), each set of injection openings comprising 3-6 injection openings.
10. Soil remediation method according to claim 1 or 2, characterized in that the injection ports of each set of injection ports are evenly distributed along the circumference of the wall of the extraction well (1).
11. A soil remediation method according to claim 1 or 2, wherein the injection direction of the injection liquid is perpendicular to the wall of the extraction well (1).
12. The soil remediation method of claim 1 or 2 wherein the time of solidification is 200min to 100h.
13. A soil remediation method according to claim 1 or claim 2 wherein the period of solidification is from 2 to 24 hours.
14. The soil remediation method of claim 1 or 2 wherein the injection further comprises at least one of a filler and an oxidant.
15. The method of soil remediation of claim 14 wherein the filler is selected from at least one of gravel, activated carbon, molecular sieves, and zeolite.
16. The soil remediation method of claim 14 wherein the oxidising agent is selected from potassium permanganate and/or potassium dichromate.
17. The soil remediation method of claim 1 or 2, wherein step 2) further comprises: an injection device (5) is arranged on the injection port.
18. A soil remediation method according to claim 17, wherein the spraying device (5) is a nozzle.
19. The soil remediation method of claim 1 or 2, wherein step 2) further comprises: firstly, the injection liquid is prepared in the preparation device (2), and then the injection liquid is driven by the conveying device (3) to be injected into the soil through the injection liquid pipeline (4).
20. A soil remediation method according to claim 19, wherein the end of the injection liquid conduit (4) extends into the injection port.
21. The method of claim 1, wherein the in situ extraction is for 24-48 hours.
22. The soil remediation method of claim 1 or claim 2 wherein the in situ extraction is done in one pass or batch.
23. A soil remediation method according to claim 1 or claim 2 wherein the distance between the centers of the tips of adjacent extraction wells is 3-5m.
24. A soil remediation method according to claim 1 or 2 wherein the extraction well (1) comprises at least a grade 2 well, the step of drilling the extraction well (1) in step 1) comprising: and drilling a next-stage well from the well wall of the previous stage.
25. A soil remediation method according to claim 1 or 2 wherein the fracking well means comprises a primary well and a secondary well, the step of drilling the extraction well (1) in step 1) comprising: the secondary well is drilled from below and in the middle of the primary well.
26. The method according to claim 1 or 2, wherein the soil remediation method further comprises: the extract is subjected to a post-treatment.
27. The method of claim 26, wherein the post-processing comprises: and separating the extract to obtain organic pollutant gas, sediment and wastewater, and performing innocent treatment on the organic pollutant gas.
28. The method of claim 27, wherein the post-processing comprises: and (3) washing and cooling the extract, performing three-phase separation in an extract treatment device (7) to obtain organic pollutant gas, sediment and wastewater, and collecting the organic pollutant gas into an exhaust gas treatment device for harmless treatment.
29. The method of claim 27 or 28, wherein the innocuous treatment is selected from at least one of absorption, adsorption, water washing, alkaline washing, membrane separation, catalytic oxidation, regenerative combustion, direct combustion, plasma technology treatment, chemical oxidation, and microbiological treatment.
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Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2002254062A (en) * 2001-02-28 2002-09-10 Shimizu Corp In site restoration method and equipment for organic- contaminated soil
JP2005040649A (en) * 2003-07-22 2005-02-17 Sumitomo Metal Mining Co Ltd Underground contamination restoration method
CN202638859U (en) * 2012-06-11 2013-01-02 上海市环境科学研究院 Vapor phase extraction heat conduction strengthening advanced oxidization in situ repairing facility for contaminated soil
CN203265251U (en) * 2013-05-24 2013-11-06 上海市环境科学研究院 Radio frequency heating vapor phase extraction repair testing device for benzene contaminated soil
CN104624623A (en) * 2015-01-30 2015-05-20 浙江博世华环保科技有限公司 In-situ extraction and remediation method for polluted site
CN109351769A (en) * 2018-12-10 2019-02-19 中国石油大学(华东) Heavy-metal contaminated soil humic acid green in-situ solidifies renovation technique
CN111097785A (en) * 2018-10-26 2020-05-05 中国石油化工股份有限公司 Method for restoring polluted soil and underground water

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2002254062A (en) * 2001-02-28 2002-09-10 Shimizu Corp In site restoration method and equipment for organic- contaminated soil
JP2005040649A (en) * 2003-07-22 2005-02-17 Sumitomo Metal Mining Co Ltd Underground contamination restoration method
CN202638859U (en) * 2012-06-11 2013-01-02 上海市环境科学研究院 Vapor phase extraction heat conduction strengthening advanced oxidization in situ repairing facility for contaminated soil
CN203265251U (en) * 2013-05-24 2013-11-06 上海市环境科学研究院 Radio frequency heating vapor phase extraction repair testing device for benzene contaminated soil
CN104624623A (en) * 2015-01-30 2015-05-20 浙江博世华环保科技有限公司 In-situ extraction and remediation method for polluted site
CN111097785A (en) * 2018-10-26 2020-05-05 中国石油化工股份有限公司 Method for restoring polluted soil and underground water
CN109351769A (en) * 2018-12-10 2019-02-19 中国石油大学(华东) Heavy-metal contaminated soil humic acid green in-situ solidifies renovation technique

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