KR101952134B1 - Method of preventing arsonic polution of the ground water and treating method of the same - Google Patents

Abstract

The present invention relates to a method for preventing arsenic contamination of groundwater taken from a tube well, capable of preventing arsenic contamination of groundwater which can occur during packer grouting, one of the processes of collecting the groundwater. The method for preventing arsenic (AS) contamination of groundwater according to an embodiment of the present invention comprises: a step of (s10) of examining bedrock constituents of strata to identify a region where a mineral including pyrite (FeS_2) exists on a geological map; a step (s20) of investigating a region where FeAsS or [FeS-As]S can be formed as FeS_2, oxygen, and water (H_2O) react with the bedrock; a step (s30) of drilling the area where the FeAsS or [FeS-As]S can be formed for the tube well; and a step (s40) of injecting cement slurry using grouting equipment to the bedrock in the tube well to prevent the groundwater from flowing out from the tube well.

Description

Technical Field [0001] The present invention relates to a method of preventing arsenic contamination of groundwater taken from a geysers,

The present invention relates to a method for preventing arsenic contamination of groundwater taken from a canal that can prevent contamination of groundwater by arsenic which may occur during the packing process, which is one of the methods for collecting groundwater, will be.

Global demand for groundwater is rapidly increasing, while contamination of groundwater by many toxic substances such as arsenic is severe.

Therefore, the method of purifying the groundwater is considered as an important problem. Among them, the in - situ purification method is recognized as one of the best alternative of the groundwater purification method due to the advantage of directly removing the pollutant source under the surface environment. Until now, immobilized reactive walls have been used mainly for in-situ purification of soil or groundwater. In the in-situ purification technology using such a fixed reaction wall, the reaction wall is installed across the flow of the ground water to remove the contaminants from the groundwater as it passes over it. For this purpose, it is often necessary to fill the reaction material through excavation Hassle.

However, the pollutant sources are distributed throughout the groundwater, whereas the areas that can be purified due to the nature of the fixed reaction walls are limited to the surrounding area where the reaction wall is located, There have been many problems in removing pollutants left on the ground.

In addition, when the number of reaction walls is increased to increase the flow of purification, there arises a problem of cost for excavation work. In the case of a large rocky area, such excavation work is also impossible.

(0001) (Patent Literature) Patent No. 10-0644164 (Portable Reactive Walls and Method for In-situ Purification of Soil or Groundwater Using the Waste Reactive Wall)

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide a method for preventing arsenic contamination of groundwater, which comprises detecting groundwater leached from the groundwater, There is a limit that can be treated only afterwards, and a method for preventing elution of arsenic (As), which is a kind of heavy metal, from such a rock layer by irradiating a rock layer in which arsenic can be detected more positively The purpose.

In addition, since these heavy metals have the characteristic of being detected in a region eluting from a specific crack region due to the characteristic of distribution, it is known that arsenic (As) among these heavy metals is pyrite, It is necessary to investigate the distribution of arsenopyrite and galena, and to verify that arsenic is in excess of domestic water quality standards to provide groundwater pollution prevention equipment for groundwater contaminated with arsenic and can not be used as drinking water. There is another purpose.

According to an aspect of the present invention, there is provided a method for preventing arsenic contamination of groundwater in an embodiment of the present invention, comprising the steps of: ) (S10) confirming the area where the mineral containing FeS ₂ is present on the geological map; A step (s20) of investigating an area where FeSS or [FeS-As] S can be formed while FeS ₂ , oxygen and water (H ₂ O) react with the rock layer; (S30), a through hole is formed through the weathered rock layer, the rock layer, and the soft layer, and the boundary between the weathered rock layer and the rock layer is formed in the through hole A second packer is installed in the interface between the rock layer and the soft layer of the through hole to prevent ground water leaking from the cracks at the interface between the weathered rock layer and the rock layer and the soft layer from mixing the surface water flowing from the weathered rock layer or the soft layer And the groundwater can be selectively taken in a specific depth aquifer, and a casing for preventing collapse of a portion where the through hole is formed is formed at a portion of the through hole that passes through the weathered rock layer, A hole for injecting the injection material is formed in a portion passing through the hole, A first hole through which the injected material is sprayed or a cement slurry can be supplied to a region of the pipe passing through the rock layer and a second hole for watering the groundwater separately from the first hole, Detecting the arsenic concentration with respect to the groundwater passing through the rock layer of the formed part, and confirming whether the arsenic concentration exceeds 50 μg / L, which is the water quality standard of domestic drinking water (s35); (S40) of injecting a cement slurry using the grouting equipment to the underground rock bed to prevent the groundwater from flowing out from the canal, wherein the FeAsS or [FeS-As] S is Arsenic concentrations were measured for the groundwater flowing through the rock layers through Reaction Formulas 1 and 2
[Reaction Scheme 1]
_{FeAsS + 7 / 2O 2 + 4H} 2 O → Fe (OH) 3 + AsO 4 3- + SO 4 2- + 5H +
[Reaction Scheme 2]
(FeS-As) S + 7 / 2O ₂ + H ₂ O → Fe ³⁺ + SO ₄ ^2- + AsO ₄ ^3- + 2H ⁺
The cement slurry is selectively injected to the rock layer containing cracks exceeding 50 μg / L, which is the water quality standard of the domestic waters of the groundwater. The cement slurry is sealed through the first hole, And then performing the process.

delete

delete

delete

delete

delete

delete

In an apparatus for preventing arsenic contamination of groundwater taken in a tunnel according to an embodiment of the present invention, the rock layer in the composition for the stratum was investigated by penetrating the weathered rock layer, the rock layer and the soft layer, and pyrite (FeS ₂ ) A through hole for confirming an area where minerals are present on a geological map and performing a drilling operation using a locating machine to form a tunnel; A first packer installed in an area including the interface between the weathered rock layer and the rock layer in the through hole to prevent the contamination of the ground water flowing into the weathered layer from the ground water leaking from the crack while stabilizing the pipe passing through the through hole; A second packer installed in an area including an interface between the rock layer and the soft layer in the through hole to stabilize a pipe passing through the through hole and preventing groundwater leaking from the crack from being mixed with surface water flowing into the softening layer; A tube having a through-hole formed at a center of a portion where the through-hole is formed to inject the injection material; A casing for preventing a portion of the through hole from passing through the weathered layer; A first hole formed for spraying the injection material or supplying the cement slurry to an area of the pipe through the rock layer; And a second hole for watering the groundwater in an area passing through the rock layer in the pipe tube, wherein a portion of the rock layer where cracks are formed is connected to groundwater passing through the rock layer through the second hole, And the cement slurry was selected as a cement slurry through the first hole for a specific crack exceeding 50 μg / L, which is the water quality standard of domestic drinking water, as a result of the investigation. To prevent the groundwater exceeding 50 μg / L, which is the water quality standard of domestic drinking water, from being taken out, and to prevent groundwater contamination caused by arsenic from the specific cracks.

delete

According to one embodiment of the present invention having the above-described constitution, the area containing arsenic among the polluted minerals for groundwater is preliminarily surveyed, , It is possible to provide a method of preventing arsenic contamination in groundwater, which can minimize the work of filling up the site.

In addition, according to the apparatus for preventing arsenic contamination of groundwater according to an embodiment of the present invention, it is possible to prevent arsenic contamination from occurring in a specific area, So that the pollution can be achieved at a low cost.

Figure 1 is a photograph showing the shape of pyrite and arsenopyrite.
FIG. 2 is a view showing a shape in which pyrite is distributed around limestone (FIG. 2 (a)) and calcite in the rock constituting the indicator.
FIG. 3 is a table comparing various chemical properties of surface water and groundwater.
FIG. 4 is a view showing a configuration of a general groundwater intake apparatus.
FIG. 5 is a schematic view showing an apparatus for preventing arsenic contamination of groundwater taken in a tunnel according to an embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described with reference to the accompanying drawings. The present invention may, however, be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. In order to clearly illustrate the present invention, parts not related to the description are omitted, and similar parts are denoted by like reference characters throughout the specification.

Throughout the specification, when a part is referred to as being "connected" to another part, it is not necessarily the case that it is "directly connected", but also includes the case where it is "indirectly connected" do. Also, when an element is referred to as "comprising ", it means that it can include other elements, not excluding other elements unless specifically stated otherwise.

Hereinafter, the composition of a method for measuring arsenic contamination concentration from groundwater of the present invention will be described with reference to the accompanying drawings.

For these surveys, it may be necessary to determine the origin and relevance of the geological origin of arsenic.

In order to determine the origin and relevance of arsenic species, it is necessary to identify the characteristics of rocks by depth in the drilling core of existing monitoring networks, and to confirm the possibility of mineral and arsenic items with possible arsenic leaching.

The mineral which contains arsenic and is presumed to be capable of arsenic leaching is pyrite (FeS ₂ ). In the case of pyrite, reacting with arsenic can have properties that are likely to be FeAsS (Arsenopyrite).

Figure 1 is a photograph showing the shape of pyrite and arsenopyrite.

Referring to FIG. 1, generally, pyrite has close symbiotic relationship with osteoporite and galena, and can contain many toxic metals such as As, Pb, Zn, Sb, Co, Ni and Sb as trace elements. You should be cautious when using it. Pyrite is rich in black platy minerals with diameters of 1 to 2 mm, which are mainly composed of metamorphic rocks. In addition, it is known that iron oxide is generated when such pyrite is oxidized, and arsenic is detected high in iron oxide produced by oxidation of such pyrite.

When the rock layer containing pyrite constitutes the main aquifer, arsenic can be released into groundwater through the reaction of water and rock. Therefore, it is considered that the amount of arsenic that can be eluted into the groundwater will increase when the groundwater flowing through the rock layer to be taken in the present invention flows through a lot of rocky pyrite.

In particular, it has been reported that pyrite is found in all sections irrespective of the depth of the drill core, which indicates that arsenic can be eluted at any depth and arsenic (As) can be detected in groundwater.

FIG. 2 is a view showing a shape in which pyrite is distributed around limestone (FIG. 2 (a)) and calcite in the rock constituting the indicator.

Referring to FIG. 2, it can be seen that pyrite is distributed in various kinds of rocks.

In addition, it may be necessary to distinguish between the weathered rock layer (10) and the rock layer (11) that form the aquifer. Generally, in the case of deep groundwater (here defined as water flowing through a weathered rock layer), it is expected that different effects will be reflected in the water quality, which can be defined as deep groundwater (here, water flowing through the rock layer 11).

FIG. 3 is a table comparing various chemical properties of surface water and groundwater.

Referring to FIG. 3, when the water quality values of the groundwater (12) and groundwater (13) are compared with each other, the average temperature of the groundwater is 22.6 ° C and the average value of groundwater is 17.7 ° C. It can be inferred that it is affected. In the case of hydrogen ion concentration (pH), the surface water (12) corresponds to an average of 7.0 and neutral, and the ground water (13) has an average of 6.2 and a weak acidity lower than the surface water (12). In the case of electric conductivity (EC), it is considered that the groundwater (13) has an average of 455 μs / cm, and the surface water (12) average 181 μs / cm.

In the dissolved oxygen (DO) category, groundwater (13) averaged 6.1 mg / L, slightly lower than surface water (12) of 7.2 mg / L. Likewise, the redox potential (Eh) of the groundwater is 166mV on average, which is lower than the average of 183mV of surface water (12). In general, the surface water (12) is characterized by the oxidized environment, which is more affected by the surface than the ground water (13). In the case of ground water (13) Environmental characteristics.

According to the survey, the groundwater (13) detected in the survey area is mainly located in metamorphic sandstone and volcanic rocks.

In addition, arsenic and redox potentials (Eh) show a negative correlation (r ² = 0.315), indicating that the concentration of arsenic increases as the concentration decreases toward the reducing environment.

On the other hand, iron and fluorine show a positive correlation with arsenic, indicating that the concentration of iron and fluorine increases with increasing concentration of arsenic.

The correlation coefficients were 0.414 and 0.428, respectively.

In the case of arsenic (As), as shown by pH (-0.527), dissolved oxygen (-0.463), and redox potential (-0.586), the higher the concentration of arsenic, Can be said to indicate a tendency to be lowered. In particular, the oxidation-reduction potential is negatively correlated with iron (Fe) and bicarbonate (HCO ₃ ) as well as with arsenic.

As described above, it can be confirmed that the arsenic (As) has a lower oxygen concentration and a lower groundwater 13 indicating a relatively reducing environment. On the other hand, iron is a constituent element of pyrite (FeS ₂ ) in which a large amount of arsenic is present in the analysis of mineral rocks.

A description will now be given of a method of forming a canopy 100 based on the investigation of the geology and topography and taking in the groundwater 13 from the canopy 100 (s30).

Groundwater (13) refers to water that is filled or filled in an empty space of sand, gravel, and rock layers below the surface of the earth. Water flowing on the surface of the earth is called surface water (12). When rain water penetrates into the ground under the influence of gravity and meets the rock bed or impervious water layer, it is called the ground water (13).

Currently, groundwater in Korea is widely used for wells, farming water, military facilities, drinking water, and manufacturing. In particular, securing resources for groundwater (13) is an important issue because it is useful for drinking and living water in mountainous areas where waterworks are not supplied.

As the development of the Internet has progressed, the progress of industrialization has led to the intensification of environmental pollution and the pollution of the soil has become serious, and the groundwater (13), which is naturally formed by permeating the soil layer, .

The strata usually consist of a layer of weathered rock with a high permeability of soil and groundwater composed of ordinary soil and sand, and a soft rock layer, which is called impervious layer, followed by a rock and a rock layer. The rock aquifer underground water formed in the lower layer of the soft rock layer is not influenced by the surface water (12) contaminated from the soil layer or the weathered rock layer, and thus it can be maintained clean and clean water quality.

However, it can be said that the soil layer and the weathered rock layer (10) perform some filtering function from various pollutants introduced from the upper surface of the earth. However, when the time of natural purification in the water pitch is short and the soil layer or the weathered rock layer There is a possibility that the surface water 12 flowing through the water surface 12 must be contaminated together.

During the development of the groundwater (13), the mind is naturally constructed to pass through the soil layer and the weathered rock layer (10) and then pass through the soft rock layer, the normal rock, and the light rock layer.

As a result, the surface water 12 which is susceptible to contamination or contamination is mixed into the groundwater 13 of the rock layer 11 which is not contaminated naturally without any resistance or filtration means, and the contamination of the groundwater 13 of the rock layer 11 Has become a major factor.

Therefore, how to protect the underground water 13 of the rock layer 11 from the contaminated surface water 12 and prevent the inflow of the underground water 13 from the groundwater 13 to the groundwater 13, It has been a major problem in water intake.

In recent years, interest in clean drinking water has been increasing due to the improvement of income level and the increase of outdoor leisure and travel, and the absolute amount of the demand is supplied through the groundwater 13 passing through the rock layer 11.

On the other hand, Pathonic Avian Influenza (AI) can be transmitted through the eyes, nose, mouth and respiratory tract due to the direct contact of the virus on dust, water and feces contaminated by infected birds. (13) contamination of groundwater (13) due to accidents caused by contamination of various groundwater (13) such as viruses is becoming an important social problem, and the seriousness of social repercussions and the increase of pollution prevention rate of groundwater (13) And the need for the development of a more robust.

As a result, studies on devices and methods for developing uncontaminated groundwater (13) have been intensified, as well as planning natural application of such a device for preventing contamination of groundwater (13) in the process of developing groundwater It is expected that it is coming to a time when it must be forced through the legislation.

FIG. 4 is a view showing a configuration of a general groundwater intake apparatus.

Referring to FIG. 4, as shown in FIG. 1, the groundwater collecting apparatus generally includes a well drilling machine having a predetermined thickness to determine the ground, and an impermeable layer 11 (also called a rock layer) To be used as drinking water, water, or the like. At this time, in order to prevent collapse of the weathered rock layer 10, a large-scale outcasing 1 and an outcasing 1 are installed, and then the rock layer 11 is excavated and drilled until it passes through a water line of the groundwater 13 (2) installed to prevent the inflow of the surface water (12), and a soil or foreign matter of the groundwater (13) to be introduced into the lower part of the enchainment (2) The concrete 3 is injected to prevent the inflow of the surface water 12 into the space between the inlet 2 and the inner wall of the inner diameter of the groundwater 13, . And a water pump (6) installed to be connected to a heart pump (5) installed in the incising (2) and in which groundwater (13) pulled up by the heart pump (5) have.

The heartbeat pump 5 is connected to the heartbeat pump 5 which is a water pump with an off-off control on the deviation signal of the water level change by the upper level sensor 7 and the lower level sensor 8 provided in the pumping water pipe 6, (5) can be moved or stopped.

In addition, a water level sensing rod capable of sensing the water level of the groundwater 13 up to a certain level may be installed in the inside of the enceasing 2.

In order to collect a large amount of the groundwater 13 and to meet the contracted amount of water, the insertion depth of the out casing 1, which is to be extended up to a portion of the rock layer 11, is not limited to the middle of the weathered rock layer 10 And even the outcasing 1 to form the perforation of the outcasing 1 to induce the surface water 12 intentionally and the ingaking 2 for grouting not only has a great number of groundwater intakes not applied, Grouting work to prevent inflow of the surface water 12 is often not performed so that the surface water 12 can be groundwater 13 without any limitation, And the contamination of the groundwater 13 is often diffused.

In such a method, the grouting operation is not performed on the ground surface of the ground water 13, but the grouting operation is simply performed by simply inserting the ingathering 2. Such a method may have a problem that the penetration depth of the ingathering 2 is limited and fundamentally the inflow of the surface water 12 to the groundwater 13 can not be blocked.

As a construction method for preventing the inflow of the surface water 12 to the ground water 13, a large diameter excavation in which the outer casing 1 can be inserted to the upper surface of the rock layer 11 during the excavation process for pumping groundwater 13 is performed Next, after inserting the outer casing 1, the concrete 4 is injected and cured therein, and the small-diameter excavation hole for inserting the incising 2 is excavated until reaching the water in the groundwater 13 , And an incising (2).

However, in this method, grouting must be carried out in a state in which the amount of water withdrawn is not correctly confirmed. In addition, when the amount of contracted water can not be secured, not only the initial excavation ratio is excessively consumed, but grouting is completed and excavation It is necessary to dispose of the ball so that the construction cost of the contractor may be excessively borne by the construction cost.

As a method for solving such a problem, there has been proposed a method of inserting the ingress 2 by inserting the out casing 1 after excavation up to the beginning of the rock layer 11, The incising 2 is inserted into the groundwater 13 while the concrete 4 is injected into the gap between the incising 2 and the inner wall of the excavation hole to cure the inflow of the surface water 12 Method.

However, this method is also difficult to inject the concrete 4 from the lower part in the process of injecting the concrete 4, and even if injected from the lower part, the gap between the ingress 2 and the inner wall of the excavation hole can not be completely blocked The concrete 4 has a limitation that it can not prevent the groundwater 13 from being contaminated by the leakage of the groundwater.

Also, even if concrete (4) is injected from the upper part, due to the nature of the concrete (4) at a narrow gap of about 50-60 mm between the incising (2) and the inner wall of the groundwater, 4) is not completely filled, and the effect of grouting is not exhibited properly.

The concrete 4 is mixed with the groundwater 13 existing between the incising 2 and the inner wall of the groundwater corridor by injecting the concrete 4 in a state where the water level of the groundwater 13 is increased, It was impossible to cure it or to get proper strength. Therefore, when the quality of the ground water 13 is important, the grouting is re-operated in the secondary tertiary so that a considerable additional construction cost is required.

One of the important things in the process of taking in the ground water 13 is the contamination degree of impurities such as arsenic (As).

Grouting process is well known as a method to reinforce the ground. In an apparatus for preventing contamination of groundwater taken in a tunnel according to an embodiment of the present invention, a grouting method may be used.

The grouting method refers to a method in which an injection pipe is inserted into the ground, the injection material is fed through the feed pipe to fill the ground, and the ground is cured by curing for a certain period of time (also referred to as gel time). Such a pouring method may be aimed at increasing the order, index or strength of the ground (reinforcement).

Recently, the mixed processing method, the high pressure spraying method, and the compaction grouting method have been developed into the grouting method, and these methods are also included in the grouting method.

However, in the apparatus for preventing arsenic contamination of the groundwater 13 taken in the vessel 100 according to an embodiment of the present invention, the vessel 100 is formed and the oxygen (O 2) supplied to the vessel 100 and the water (H2O) prevents the formation of arsenopyrite, which can be called a round rock containing arsenic, or arsenic ions are dissolved in the groundwater 13 through it, so that the arsenic ion concentration (the allowable standard value of arsenic for drinking water is 50 μg / L (the water quality standard of domestic drinking water) is increased, so that it is possible to minimize the case where the operation of filling up the well 100 is to be repeated.

Therefore, it is necessary to investigate whether or not pyrite is distributed in the water intake area of the groundwater (Fig. 1 (a)). s10) In particular, since the aquifer to be taken in the present invention can be regarded as the object of the groundwater 13, the surface water 12, which is relatively high in pollution degree (the pollution degree is not limited to the contamination due to arsenic) Shall be excluded from the subject.

In this case, the stratum class which can be a problem is degenerated sand rocks.

The modified sandy rocks may include quartz schist, mica schist, quartzite, and limestone rock. Of these, limestone can contain pyrite, up to 1 mm in size, as an acid. These pyrite may be reddish oxidized or oxidized pyrite particles in some weathered areas.

These results can be obtained from geological investigations. It can be seen that the particle size of the pyrite is larger and more dense at the point where the limestone is denatured by hydrothermal alteration. Judging from the results of these geological surveys, pyrite, which contains arsenic or reactive elements capable of leaching arsenic (As) into groundwater (13), was found at the depth of field, regardless of depth.

The iron (FeS2) is reacted with arsenic, oxygen and water, which are contained as impurities.

[Chemical Formula 1]

FeS ₂ + As → [Fe-As] S + (FeS-As) S

A reaction that transforms into a sulfide mineral containing arsenic can occur (s20).

When the pyrite is transformed into a mineral containing arsenic and sulfur, the reaction represented by the formula (1) occurs only in a region where pyrite exists. When the pyrite is transformed into a mineral containing arsenic and sulfur, (3), the concentration of arsenic in the groundwater 13 can be increased.

(2)

_{FeAsS + 7 / 2O 2 + 4H} 2 O → Fe (OH) 3 + AsO 4 3- + SO 4 2- + 5H +

 (3)

(FeS-As) S + 7 / 2O ₂ + H ₂ O → Fe ³⁺ + SO ₄ ^2- + AsO ₄ ^3- + 2H ⁺

(FeAsS) and (FeS-As) S) containing arsenic are contained in the form of arsenic ions under the condition of water and oxygen, Can be formed.

In the apparatus for preventing arsenic contamination of groundwater through the leaching of arsenic in the groundwater 13 taken in the irrigation canal 100 according to an embodiment of the present invention, It can be a problem.

FIG. 5 is a schematic view showing an apparatus for preventing arsenic contamination of groundwater taken in a tunnel according to an embodiment of the present invention.

Referring to FIG. 5, a through hole 115 may be formed through the weathered rock layer 10, the rock layer 11, and the soft layer 130 from above. The through-hole 115 may be formed to penetrate through the tube 100 using a dispenser.

In order to prevent disturbance of groundwater in the process of forming the through hole 115 in the vessel 100 for taking groundwater according to an embodiment of the present invention and to selectively receive groundwater from a specific depth aquifer, (122, 132).

5, when the first and second packers 122 and 132 are made of a material having elasticity between the weathering-resistant layer 10, the rock layer 11 and the soft layer 120, the through holes 115 It is possible to prevent the phenomenon that the groundwater 13 leaking from cracks (unassigned numbers) is mixed with the surface water 12 flowing into the weathering-resistant layer 10 or the soft layer 120.

Also, the casing 124 can be formed to prevent the ground collapse, which is a phenomenon that may occur because the weathering layer 10 is weak.

A portion of the tube-to-tube 106 that passes through the rock layer 11 is injected with an injection material or is injected into a cement- A first hole 108 capable of supplying a cement slurry may be formed. In addition, a second hole 109 for watering the groundwater 13 may be formed.

The groundwater 13 may be connected to a pump (not shown) through the pipe 106 and an As concentration or the like of the groundwater 13 formed in the rock layer 11 may be measured. have.

At this time, the pipe 106 can be connected to the outside air, so that outside air can be introduced into the pipe 106. When external air is introduced and water is introduced through cracks, it is possible to form an arsenopyrite by the reaction as shown in Formula 3. The formation of arsenopyrite may increase the concentration of arsenic in the groundwater.

In order to prevent the arsenic leaching through the groundwater (13) and the reaction between the arsenic leachate and the groundwater (13), the arsenic concentration measurement for the leached portion of the groundwater (13) may be performed first (S35).

When the concentration of arsenic is above 50 μg / L (based on domestic water quality), the groundwater (13) taken from the arsenic has the property that it can not be used for food.

It is preferable that no further groundwater 13 is taken for the crack supplying the groundwater 13.

For the rock layer 11 containing such a crack, it is preferable to proceed with the operation (s40) of injecting and sealing the cement slurry. The work of filling the groundwater 13 portion indicated by A in FIG. 5 with the cement slurry through the first or second holes 108 and 109 can be performed.

Through the process of blocking the cracks detected by arsenic, it is possible to easily take out the groundwater to the ground while minimizing the process of closure (pitting).

An apparatus for preventing arsenic contamination of groundwater taken in a tunnel, comprising: a through hole (115) penetrating through the weathered rock layer (10), the rock layer (11) and the soft layer (130) A first packer 122 installed in an area including an interface between the rock layer 11 and the soft layer 130 and a second packer 122 installed in a region including the interface between the rock layer 11 and the soft layer 130 in the through hole 115, A packing tube 106 is formed at the center of a portion where the packer 132 and the through hole 115 are formed and a crack is formed in the tube tube 106 and the rock layer 11 The arsenic concentration was measured with respect to the ground water 13 taken from the area where the crack 13 was formed in the area where cracks were formed and the arsenic concentration was found to be a crack exceeding 50 μg / And the cement slurry (ce ment slurry may be injected and cured to prevent the ground water 13 from being taken out.

In addition, the rock layer 11 is investigated in the structure of the ground layer, and an area where a mineral including pyrite (FeS ₂ ) exists is confirmed on a geological map, and excavation work is performed using a deposition machine, Arsenic contamination can be minimized.

While the present invention has been particularly shown and described with reference to specific embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the following claims It will be apparent to those of ordinary skill in the art.

1: Out casing 2: Inching
3: Pipe for strainer 4: Concrete
5: heart pump 6: water pump
10: weathered rock layer 11: rock layer
12: Surface water 13: Ground water
100: Jangjung 130: Soft layer
122: first packer
130: soft layer 132: second packer

Claims (4)

In an arsenic (As) contamination prevention method for groundwater,
A step (s10) of examining the rock bed during the formation of the strata, and confirming the area where the mineral containing pyrite (FeS ₂ ) exists on the geological map (s 10);
A step (s20) of investigating an area where FeSS or [FeS-As] S can be formed while FeS ₂ , oxygen and water (H ₂ O) react with the rock layer;
The sphere is pierced with respect to an area where the FeAsS or [FeS-As] S can be formed (s30)
A first packer is installed at an interface between the weathered rock layer and the rock layer in the through holes, and a second packer is installed at the interface between the rock layer and the soft layer of the through holes to form the weathered rock layer, the rock layer and the soft layer, The groundwater leaking from the cracks at the interface between the rock layer and the soft layer is selectively prevented from mixing with the groundwater introduced from the weathered rock layer or the soft layer,
Wherein a casing for preventing collapse of a portion where the through hole is formed is formed at a portion of the through hole passing through the weathered layer,
And a pipe through which the injection material can be injected is formed in a portion passing through the through hole,
A first hole through which the injected material is sprayed or a cement slurry can be supplied to the passage pipe through the rock layer and a second hole for watering the groundwater separately from the first hole,
Detecting the arsenic concentration with respect to the groundwater passing through the rock layer in the cracked part of the rock layer, and determining whether the arsenic concentration exceeds 50 μg / L, which is the water quality standard of domestic drinking water;
(C) injecting a cement slurry using the grouting equipment to prevent the groundwater from flowing out from the gravel bed,
The FeAsS or [FeS-As] S can be determined by measuring the arsenic concentration with respect to the groundwater flowing through the rock layer through the following equations (1) and (2)
[Reaction Scheme 1]
_{FeAsS + 7 / 2O 2 + 4H} 2 O → Fe (OH) 3 + AsO 4 3- + SO 4 2- + 5H +
[Reaction Scheme 2]
(FeS-As) S + 7 / 2O ₂ + H ₂ O → Fe ³⁺ + SO ₄ ^2- + AsO ₄ ^3- + 2H ⁺
The cement slurry is selectively injected to the rock layer containing cracks exceeding 50 μg / L, which is the water quality standard of the domestic waters of the groundwater. The cement slurry is sealed through the first hole, The method of claim 1, wherein the arsenic-contaminated soil is groundwater.
delete In an apparatus for preventing arsenic contamination of groundwater,
The rock layers of the weathered rocks, rocks, and soft layers were investigated to determine the area where the mineral including pyrite (FeS ₂ ) exists on the geological map. A through hole for forming a tunnel;
A first packer installed in an area including the interface between the weathered rock layer and the rock layer in the through holes to stabilize a pipe passing through the through hole and preventing groundwater leaking from cracks from being mixed with surface water flowing into the weathered rock layer;
A second packer installed in an area including the interface between the rock layer and the soft layer in the through hole to stabilize a pipe passing through the through hole and preventing groundwater leaking from the crack from being mixed with surface water flowing into the soft layer;
A tube having a through-hole formed at a center of a portion where the through-hole is formed to inject the injection material;
A casing for preventing a portion of the through hole from passing through the weathered layer;
A first hole formed for spraying the injection material or supplying the cement slurry to an area of the pipe through the rock layer; And
And a second hole for watering the groundwater in an area passing through the rock layer in the pipe,
In the portion of the rock layer where cracks are formed, the arsenic concentration of the ground water passing through the rock layer is checked through the second hole to exceed 50 μg / L,
As a result of the above investigation, cement slurry was selectively injected and cured through the first hole for a specific crack exceeding 50 μg / L, which is the water quality standard of domestic drinking water, and it exceeded 50 μg / L And preventing arsenic from groundwater contamination from the specific crack. The apparatus for preventing arsenic contamination of groundwater as claimed in claim 1, delete

Images