KR20100087852A - A barrier system and remediation method of contaminated soil using ground freezing - Google Patents

Abstract

PURPOSE: A contaminated soil barrier system using a ground freezing and a contaminated soil remediation method are provided to remove contaminant by blocking the flow of the contaminant on the contaminated soil without chemical reaction. CONSTITUTION: A contaminated soil remediation system using a ground freezing includes a barrier wall(100) comprised of a plurality of freezing pipes, a refrigerant injector(200) connected to the freezing pipe, and a plurality of extraction wells(300) inserted into the contaminated soil. The barrier walls face each other and make a pair. The extraction well is inserted into the contaminated soil between the barrier walls. A cover for covering the contaminated soil surrounded with the barrier wall is formed on the upper side of the barrier wall.

Description

A Barrier System And Remediation Method Of Contaminated Soil Using Ground Freezing}

The present invention relates to a pollution ground shielding system and a purification method using ground freezing, and more particularly, by inserting a freezing pipe into the soil and converting the soil into a frozen ground to guide the liquid pollutants in a certain direction. The present invention relates to a shielding system and a purification method using ground freezing, which facilitate extraction of contaminants from the ground through extraction wells.

In general, ground purification methods include electric restoration methods, soil washing methods, permeable reaction wall methods, and microbial recovery methods.

First of all, the electro restoration method has been applied to the dehydration and stabilization of the ground by moving water and pollutants by electrolysis reaction, and has recently been applied to the purification of polluted soil in the environment. The electro-restoration method uses contaminants such as heavy metals and inorganic substances in the ground to the cathode by using electrolysis, electroosmotic and electrophoresis in viscous soils with low permeability, and then pump them to the ground using a pump. Although it is used to extract and remove, the method has a problem in its application because the occurrence of electroosmotic phenomenon is weak in sandy soils with high permeability.

In addition, the soil washing method injects pure water or water containing additives to increase the solubility of pollutants in sandy soil, extracts contaminated groundwater from extraction wells formed in the opposite direction, and recycles groundwater treated on the ground. However, the soil washing technique is used to extract organic substances in the ground and water-soluble contaminants in groundwater by using a pump to remove them from the ground by using water washing power and chemical solution desorption power in sandy soils with high permeability. In this method, there is a problem in applicability because water migration is not smooth in low permeability viscous soil, and there is a problem of secondary contamination by chemicals because a separate chemical solution (material) must be used.

In addition, the permeable reaction wall method is to remove the contaminants in the contaminated groundwater by installing a permeable reaction wall at the bottom of the groundwater flow direction of the high permeability sandy soil and low permeability viscous soil to purify at the site of the site underground However, the method requires a parallel method of moving contaminated water to a point where the permeable reaction wall is installed, and there is a problem in that the excavation work cost of installing the permeable reaction wall in the ground is large.

Various techniques have been proposed as a way to solve this problem. For example, as shown in FIG. 1, Korean Patent Registration No. 667465 "Purification and restoration of contaminated soil mixed with sandy soil and viscous soil by the electric washing reaction pile technique. Apparatus "is presented, the technique is to install the anode electrode 10 and the cathode electrode 20 at a predetermined interval inside the soil ground, so that the pollutants are adsorbed and removed on the cathode electrode 20 side to be purified. The reaction pile 60 is installed, the power supply means 30 for supplying the DC-converted power to the positive electrode 10 and the negative electrode 20, and the washing water and the inside of the positive electrode 10; It is characterized in that the washing water supply means for supplying a chemical solution 40 is installed on the ground. However, the above technique can be used for the purification of contaminated ground regardless of the type of earth and sand, but in addition to the electrolysis reaction, it is cumbersome to inject chemical solution and washing water separately, and to the chemical solution (material) for purification. There is a problem that may cause a second pollution.

On the other hand, the ground freezing method is a method of embedding a pipe at a predetermined interval in the ground and flowing a refrigerant therein to freeze the ground water of the ground to solidify the ground. Artificially frozen ground can form a low permeability coefficient of shielding and a high strength flow control wall during a period of maintaining a predetermined freezing temperature. This method of ground freezing has the advantages of efficient ordering, applicable to all soils, complete removal after construction, and eco-friendly because there is no need to use separate chemicals. This method of ground freezing is used as the order structure for excavation and construction of other construction structures in coastal areas with high groundwater level or high water content. The freezing zone is formed to enable efficient construction.

Therefore, this ground freezing method can be used as a barrier wall for shielding pollutant flow control during the cleanup work in waste landfills, industrial complexes, and US military bases, and it is an environmentally friendly method without any chemical reactions. It can be used, but the research is insufficient.

The present invention provides a shielding system and a method for purifying polluted ground using ground freezing, which is capable of removing pollutants and removing pollutants in an environmentally friendly environment without chemical reactions, regardless of the type of soil. have.

The shielding system using the ground freezing of the present invention as a means for achieving the above object comprises a shielding wall consisting of a plurality of freezing pipes inserted into the soil; A refrigerant injection unit connected to each of the freezing pipes; Characterized in that it consists of a plurality of extraction wells inserted into the soil ground in the state of play with the shield wall.

The shielding wall may be configured in various ways. The pair of shielding walls may be configured to face each other, and the extraction well may be inserted into the contaminated ground between the shielding walls, and the shielding wall may form an arc. The extraction well may be configured to be inserted into the contaminated ground inside the arc of the shielding wall.

As mentioned above, when the shielding wall is formed in an arc shape, a cover may be formed on an upper portion of the shielding wall to cover the soil on which the shielding wall is wrapped.

The freezing pipe is preferably configured to be inserted into the impervious layer ground of the contaminated ground.

Meanwhile, in the present invention, various embodiments of the freezing pipe are provided, and an example includes a plurality of wing parts protruding bilaterally in the longitudinal direction of the freezing pipe, and as another example, a plurality of protrusions in the longitudinal direction of the freezing pipe are provided. It is configured, the protrusion is presented an example consisting of a shape extending in length from the top to the bottom of the freezing pipe, as another example, the freezing pipe is configured in a straight rod shape, inserted into the soil to form a slope gradient, the The angle gives an example to form an inclined gradient in a shape in which the clearance decreases toward the bottom of the extraction well and the soil.

On the other hand, the soil ground purification method using the ground freezing of the present invention comprises the steps of forming a shielding wall by inserting a freezing pipe into the soil; Injecting a refrigerant into the freezing pipe to freeze the contaminated ground; And inserting an extraction well into the frozen soil ground to discharge the pollutants to the outside.

Contaminated ground shielding system and purification method using the ground freezing of the present invention has the advantage that can block the flow (mouth) of contaminants into the contaminated ground as well as the removal of contaminants in the shielding wall by configuring the shielding wall in the soil.

In addition, the present invention ground pollution shielding system and purification method using the ground freezing has the advantage that can be removed from the soil contaminated environmentally without the addition of chemicals, microorganisms.

In addition, the present invention contaminated ground shielding system and purification method using the ground freezing has the advantage that can be applied regardless of the type of soil soil.

Hereinafter, the configuration and operation of the present invention will be described in more detail with reference to the accompanying drawings. In describing the present invention, the term or word used in the present specification and claims is based on the principle that the inventor can appropriately define the concept of the term in order to best describe the invention of his or her own. It should be interpreted as meanings and concepts corresponding to the technical idea of

Figure 2 is a side cross-sectional view showing a soil ground purification system by the ground freezing of the present invention, Figures 3a and 3b is a side cross-sectional view showing the operating relationship of the soil ground purification system by the ground freezing of the present invention, Figures 4a and 4b 5 is a plan view showing an embodiment of a shielding wall that is one component of a soil freezing system by ground freezing, and FIGS. 5A to 5C illustrate an embodiment of a freezing pipe that is one component of the soil freezing system by ground freezing. 6A to 6C are flowcharts of the soil ground purification method by ground freezing according to the present invention.

As shown in FIG. 2, the soil ground purification system by ground freezing according to the present invention

A shield wall 100 composed of a plurality of freezing pipes 110 inserted into the contaminated ground S and a refrigerant injector 200 connected to the freezing pipes 110 and the shielding wall 100, respectively. Consists of a plurality of extraction well 300 is inserted into the contaminated soil (S) in the shielding wall (100) to prevent the pollutant (D) from the source of contamination in the contaminated soil (S) to the water (W), etc. And form a contaminant (D) in a predetermined direction as the shielding wall (100) is changed to the freezing ground (FS) of the contaminated ground (S) by the action of the shielding wall 100 to the outside through the extraction well (300) To let go. The contaminant (D) can be induced in a certain direction because the freezing point of the contaminant is lower than the moisture contained in the ground, so that the pollutant remains liquid even when the ground is frozen. Pollutants will be transported.

The shielding wall 100 refers to a wall formed by the freezing pipe 110 which is inserted at a predetermined interval, the shielding wall 100 according to the shape that the freezing pipe 110 is inserted into the soil ground (S). The shape of the can also be configured in various ways, embodiments according to the shape of the shielding wall 100 will be described separately below.

As mentioned above, the shielding wall 100 formed by the insertion of the plurality of freezing pipes 110 has a freezing ground FS formed around the freezing pipe 110 by the injection of refrigerant into the freezing pipe 110. Accordingly, the overlapping portion of the freezing ground FS is formed between the freezing pipes 110 and the flow of the contaminant D is blocked by the overlapping portion. In addition, the compaction effect is generated on the ground by forming the overlapping portion of the frozen ground FS, and the rigid wall is formed by the frozen ground FS around the shielding wall 100 by the compaction.

As shown in FIG. 2, the freezing pipe 110 constituting the shielding wall 100 is configured to be filled with a refrigerant in the hollow by directly forming a hollow inside. The freezing pipe 110 shown in FIGS. 1 and 2 shows a basic example of the present invention, and an embodiment according to the shape of the freezing pipe 110 will be described separately below.

It is obvious that the spacing of the freezing pipe 110 may be selectively configured in consideration of the ground conditions such as engineering characteristics including the water content of the soil.

Although the shielding wall 100 is not shown in the drawing, a plurality of freezing pipes 110 may be inserted into the contaminated ground S to form a single shielding wall 100. The shielding wall 100 is formed in the soil ground (S) to block the flow path (f) of the pollutant and to block the inflow of the pollutant (D) into the water (W) and the like, the shielding wall (100) As the contaminated ground at the periphery of the freezing pipe 110 forming the freezing ground converts the contaminant D in one direction, that is, away from the shielding wall 100, the contaminant D is extracted 300. It is to let out through the outside. When the first stage shielding wall 100 is configured as described above, the pollutant D may be induced only in one direction, and thus, the pollutant D is more functional in blocking the flow path f of the pollutant than the outflow of the pollutant.

Accordingly, the present invention provides an arc-shaped shielding wall 100b with a structure completely covering two shielding walls 100a and a contaminated ground S as an example of the shielding wall 100.

In FIG. 4A, the two-stage shielding wall 100a is shown, and the two-stage shielding wall 100a constitutes a pair in a shape opposite to each other. Thus, the soil ground (S) is located between the pair of shielding walls (100a) to supply the refrigerant through the freezing pipe 110 to each shielding wall (100a) area of the freezing ground (FS) toward the center direction As the process proceeds, the pollutant (D) flows in the center direction, thereby inducing the pollutant (D) in both directions, and thus extracting the pollutant (D) more easily than the above-mentioned shielding wall (100). Can be spilled to 300. In addition, the shielding wall (100a) is composed of two stages to be able to block the flow path (f) of the pollutant in two stages.

Meanwhile, the present invention provides an arc-shaped shielding wall 100b as another example of the shielding wall 100. As shown in FIG. 4B, the arc-shaped shielding wall 100b arranges the freezing pipe 110 to form an arc so that the shielding wall 100b formed by the freezing pipe 110 completely surrounds the soil soil S. As shown in FIG. It consists of shapes. In this way, by supplying a refrigerant through each freezing pipe 110, as the region of the freezing ground FS proceeds in the center direction, the pollutant D flows in the center direction. ), The removal rate of the contaminant D inside the shielding wall 100b will be higher than that of the shielding wall 100a. The arc-shaped shielding wall 100b as shown in FIG. 4B may be more effective in increasing the removal rate of the contaminant D in the contaminated ground S when the contaminated ground S is not relatively wide. In addition, it can be easily leaked to the extraction well (300). In addition, since the shielding wall 100b guides the pollutant D in the center direction, it is easy to detect the position of the pollutant D when the pollutant D is discharged through the insertion of the extraction well 300. There is an advantage that can reduce the number of extraction well 300 for the discharge of pollutants (D).

On the other hand, in the case of configuring to surround the soil (S) as in the case of the shielding wall (100b), the cover 120 covering the soil (S) covered by the shielding wall (100b) on the upper portion of the shielding wall (100b) Is more preferably configured. That is, when the contaminated ground S inside the shielding wall 100b is converted to the frozen ground FS, the freezing ground FS is blocked from the outside atmosphere to enable efficient freezing with a small amount of refrigerant. The cover 120 may be separated when the contaminated ground (S) inside the shielding wall (100b) is converted to the freezing ground (FS) to insert the extraction well 300, may spill the pollutant (D), As shown in FIG. 2, the extraction well 300 may be inserted in the state in which the cover 120 is not separated to allow the pollutant D to flow out.

In addition, the freezing pipe 110 may be configured as a straight rod as shown in Figure 2, etc., various embodiments of the freezing pipe 110 as shown in Figures 5a to 5c.

First, the freezing pipe 110a shown in FIG. 5A includes a plurality of wing portions 111a protruding in both directions in the longitudinal direction. That is, the wing portions 111a formed in the respective freezing pipes 110a are formed to face each other in parallel to the direction in which the freezing pipes 110a are arranged. The freezing ground FS formed at the periphery of the freezing pipe 110a by the configuration of the freezing pipe 110a will be further extended to the side in the drawing according to the shape of the wing 111a. As the freezing ground (FS) overlapping region is formed by the expanded shape of, the flow path f of the pollutant D by the shielding wall 100 can be more firmly blocked. That is, the freezing pipe (110a) is a structure for tightly blocking the flow path (f) of the pollutant (D).

Meanwhile, as another embodiment, the freezing pipe 110b shown in FIG. 5B has a protruding portion 111b formed in the longitudinal direction, and the two-level blocking wall 100a or the arc-shaped blocking wall 100b shown in FIGS. 4A and 4B. As in the case of), it is to present a case in which the protrusions 111b protruding from each other are formed as opposing freezing pipes 110b. In particular, the protrusion 111b is configured to have a length that extends from the upper end to the lower end of the freezing pipe 110b, that is, as shown in FIG. 5B, the length of the protrusion 111b-1 at the lower side is a protrusion at the upper end. The case where it is comprised larger than (111b-2) is shown. As such, the length of the protrusion 111b-1 on the lower side is larger than the protrusion 111b-2 on the upper side of the freezing ground FS formed by the protrusion 111b-1 on the long side. By freezing the ground in a wider range than the freezing ground (FS) formed by the protruding portion (111b-2) of the shorter upper side, the contaminant (D) between the freezing ground (FS) is formed while forming a slope gradient It is induced by the upward direction and thus the insertion length of the discharge pipe 300 is reduced by the contaminant (D) is directed upward, so that the pollutant (D) can be easily discharged to the outside.

Meanwhile, as another embodiment, the freezing pipe 110c shown in FIG. 5C may also face the same freezing as in the case of the two-stage blocking wall 100a or the arc-shaped blocking wall 100b shown in FIGS. 4A and 4B. As the pipe 110c, each of the opposed freezing pipes 110c has a shape in which the clearance narrows toward the lower end of the soil ground S. That is, the freezing pipe 110c is configured as a straight rod shape, as shown in Figure 2, etc., to form a gradient only at the insertion angle of the soil ground (S). In this configuration, as the freezing ground FS formed by the freezing pipe 110c also forms an inclined gradient, the range of the freezing ground FS increases in the lower direction on the drawing, and thus, contaminants D therebetween. Is induced in the upward direction by the freezing ground (FS) formed while forming an inclined gradient and thus the insertion length of the extraction well 300 is reduced by the contaminant (D) is directed upward so that the contaminants (e.g., D) can be leaked to the outside.

On the other hand, the soil ground purification method using the ground freezing of the present invention as shown in Figures 6a to 6c, first has a step of forming a shielding wall by inserting a freezing pipe in the soil. In this step, puncturing is carried out using the puncturing means on the soil, and the freezing pipe 110 is inserted into the puncture. Insertion of the freezing pipe 110 is punctured and inserted so that one stage of shielding film, two stages of shielding film or arc-shaped shielding film is constructed in consideration of engineering characteristics such as construction conditions, ground water content, strength, and the like. After the insertion of the freezing pipe 110, the filling material is filled between the perforation and the freezing pipe 110. In addition, when the freezing pipe 110 is inserted into the arc-shaped shielding film 100b, the cover 120 includes a cover 120 covering the soil ground S covered by the shielding film 100b.

Next, the refrigerant injector 200 is connected to each of the freezing pipes 110 to inject the refrigerant to convert the contaminated ground S into the frozen ground FS. In this way, by converting the soil ground (S) into the frozen ground (FS), the pollutant (D) is induced in one direction.

Finally, the extraction well 300 is inserted into the contaminated soil S converted to the frozen ground FS, and the contaminants D induced in one direction are discharged to the outside.

1 is a schematic diagram showing a prior art,

Figure 2 is a side cross-sectional view showing a soil ground purification system by the present inventors ground freezing,

Figure 3a and Figure 3b is a side cross-sectional view showing the operation relationship of the soil ground purification system by the present inventors ground freezing,

4A and 4B are plan views showing an embodiment of a shielding wall which is one component of the soil ground purification system by the ground freezing of the present invention;

5a to 5c are cross-sectional views showing an embodiment of a freeze pipe which is one component of the soil ground purification system by the ground freezing of the present invention,

6a to 6c is a flow chart of the soil ground purification method by the present invention ground freezing.

<Description of the symbols for the main parts of the drawings>

100: shielding wall 110: freezing pipe

200: refrigerant injector 300: extraction well

Claims (9)

A shielding wall composed of a plurality of freezing pipes inserted into the soil; A refrigerant injection unit connected to each of the freezing pipes; The soil ground purification system using ground freezing, characterized in that composed of a plurality of extraction wells inserted into the soil soil in the state of clearance with the shielding wall. The method of claim 1, The shielding wall is composed of a pair so as to face each other, the extraction well is purified using the ground freezing system, characterized in that inserted into the contaminated ground between the shielding wall. The method of claim 1, The shielding wall is configured to form an arc, and the extraction well is purified by the ground freezing system, characterized in that inserted into the contaminated ground inside the arc formed by the shielding wall. The method of claim 3, wherein Purification system using the ground freezing, characterized in that the upper cover of the cover is configured to cover the soil contaminated by the shielding wall. The method of claim 1, The freezing pipe is ground purification system using ground freezing, characterized in that inserted into the impermeable ground of the soil. The method of claim 1, The freezing pipe is a purification system using ground freezing, characterized in that a plurality of wings protruding in both directions in the longitudinal direction. The method of claim 1, The freezing pipe is composed of a plurality of protrusions in the longitudinal direction, the projection is a purification system using the ground freezing, characterized in that the length is formed in the shape of the length of the upper end of the freezing pipe. The method of claim 1, The freezing pipe is ground purification system using the ground freezing, characterized in that the slope is formed in the shape of the clearance decreases toward the bottom of the extraction well and the soil. Inserting a freezing pipe into the contaminated ground to form a shielding wall; Injecting a refrigerant into the freezing pipe to freeze the contaminated ground; And inserting an extraction well into the frozen soil ground to discharge the pollutants to the outside.

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