JPH0748827A - Soil purification device and method - Google Patents

Abstract

(57) [Summary] [Objective] To provide a soil purification device and method capable of removing pollutants from contaminated soil. [Constitution] A soil purifying apparatus of the present invention comprises a container 2 as a storage means capable of storing soil containing predetermined ions and water.
A power source 4 capable of applying a predetermined voltage, an electrode electrically connected to the power source 4 and comprising an anode 5a, 5b and a cathode 2 which is a container, and ions collected around at least one of the anode and the cathode. And pumps 6 and 10 as a discharging means capable of discharging the water with water out of the container 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a soil purification apparatus and method, and more particularly to a soil purification apparatus and method suitable for redevelopment work and the like.

[0002]

2. Description of the Related Art When redevelopment work is carried out using a site such as a chemical factory, mercury, cadmium,
May contain heavy metals such as lead and chrome, and cyan.

These harmful substances are used as insolubilizing agents such as cement, sodium sulfide, ferrous sulfate, etc. in consideration of the influence on the environment, even if the contained amount is a small amount of about several ppM. Sufficient safety was ensured by mixing and preventing elution, or by storing in a concrete container to prevent leakage to the outside.

[0004]

However, since the conventional treatment techniques do not remove pollutants such as heavy metals from the contaminated soil, there is a problem that the contaminated soil cannot be reused. Was there.

Further, in order to store the concrete container containing the contaminated soil for a long period of time while sufficiently considering the influence on the environment, it is necessary to solve another problem such as a storage space.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a soil purifying apparatus and method capable of removing pollutants from contaminated soil.

[0007]

In order to achieve the above object, the soil purifying apparatus of the present invention has, as described in claim 1, a storage means capable of storing soil containing predetermined ions and water, and a predetermined storage means. A power source capable of applying the voltage, an electrode composed of an anode and a cathode electrically connected to the power source, and the ions collected around at least one of the anode and the cathode, together with the water, outside the accommodating means. And a discharging means capable of discharging the same.

Further, the soil purifying apparatus of the present invention comprises:
The power source is capable of controlling the generated voltage below a predetermined value so that the ions do not substantially cause an electrode reaction at the interface between the electrode and the soil.

Further, the soil purifying apparatus of the present invention comprises:
The discharging means is provided with a filtering means capable of selectively permeating water and ions.

Further, the soil purifying apparatus of the present invention comprises:
The filtering means is formed of a conductive material and used as an electrode.

Further, the soil purifying apparatus of the present invention comprises:
The accommodating means of is made of a conductive material and is used as a cathode.

Further, according to the soil purification method of the present invention, as described in claim 6, the step of applying a predetermined voltage to the soil containing predetermined ions and water, and the step of applying the predetermined voltage to the ions in the soil by the voltage. And a step of discharging the moved ions together with water from the soil to purify the soil.

[0013]

In the soil purifying apparatus and method of the present invention,
First, the soil containing predetermined ions and water is stored in the storage means. Here, the accommodating means is made of, for example, a conductive material and is used as a cathode.

Next, the anode is inserted into the soil and a voltage is applied between both electrodes.

When the voltage value is a proper value, the ions contained in the soil move to the anode or the cathode, and the ion concentration around the electrode becomes high.

Next, the ions that have moved to the periphery of the electrode are discharged outside the container together with water. Here, if necessary, a filtering means is provided to selectively discharge water and ions from the soil.

[0017]

Embodiments of the soil purifying apparatus and method of the present invention will be described below with reference to the accompanying drawings.

(First Embodiment) FIG. 1 (a) is a schematic sectional view of a soil purifying apparatus according to the first embodiment.

The soil purifying apparatus of this embodiment has a container 2 as a storage means capable of storing the soil 1 containing the water 3 in which the heavy metal ions such as mercury, cadmium and lead and the cyan ions are dissolved.
Equipped with.

In addition, the soil purification apparatus of this embodiment is the soil 1
Is provided with a power source 4 capable of supplying a direct current by applying a predetermined voltage, and positive electrodes 5a and 5b inserted into the soil 1 are electrically connected to the positive side of the power source 4.

The anodes 5a and 5b are preferably made of, for example, carbon or a predetermined metal.

In this embodiment, the container 2 is made of a conductive material and electrically connected to the negative side of the power source 4, whereby the entire container 2 is constructed as a cathode.

The container 2 is preferably made of, for example, steel in consideration of the need to support the weight of the soil 1.

The power source 4 can control the generated voltage to a predetermined value or less so that the ions do not substantially cause an electrode reaction at the anodes 5a and 5b and the cathode 2.

That is, since each ion of lead, chromium, mercury, etc. has a decomposition voltage peculiar to each ion, in consideration of the kind of ions contained in the soil 1, the decomposition voltage should be below these decomposition voltages. It is designed to adjust the voltage value.

FIG. 1 (b) is a sectional view taken along the line AA of FIG. 1 (a).

As can be seen from the figure, the container 2 has, for example, a box shape, and the anodes 5a and 5b are the soil 1 contained in the container 2.
It is located near the center of. Here, the distance between the inner wall of the container 2 and the anodes 5a and 5b, or the distance between the anodes 5a and 5b is preferably about 2 m, for example.

Referring again to FIG. 1 (a), in the soil purifying apparatus of this embodiment, cations such as mercury and cadmium gathered in the vicinity of the cathode 2 can be discharged together with water to the outside of the container 2. A pump 6 as a means is provided.

Inside the container 2 which is the cathode, a non-woven fabric 8 and gravel 9 as a filtering means capable of selectively permeating water and ions from the soil 2 are provided on the wall side and the bottom side of the container 2, respectively. The gap between the non-woven fabric 8 and the container 2 or the gravel 9 is also used as a drain layer.

Similarly, the soil purification apparatus of this embodiment is provided with a pump 10 capable of draining anions such as cyan, which have gathered around the anodes 5a and 5b, together with water to the outside of the container 2.

FIG. 2 is a detailed vertical sectional view around the anodes 5a and 5b.

As can be seen in the figure, the anodes 5a and 5b are
A large number of holes 21 are provided on the cylindrical surface of the hollow cylindrical member.

That is, the anodes 5a and 5b also act as strainers for selectively extracting only water and ions from the surrounding soil 1 through the holes 21.

The pump 1 is placed inside the hollows of the anodes 5a and 5b.
The pipe 22 connected to 0 is arranged at an appropriate position so that the anions collected inside the anodes 5a and 5b are pumped together with water by the pump 10 through the pipe 22.

In the soil purification apparatus of this embodiment, first, the contaminated soil 1 containing heavy metal ions and the like is put in the container 2. In addition, before carrying in the soil, the nonwoven fabric 8 and the gravel 9 are appropriately arranged. Also, if the soil is dry, water should be injected as appropriate.

After the soil 1 is carried into the container 2, the power source 4 is activated to apply a voltage between the anodes 5a and 5b and the container 2 which is the cathode.

Here, the voltage value is controlled so that each ion does not substantially cause an oxidation or reduction reaction at the electrode and is attracted to the vicinity of each electrode, for example, about 10 volts.

When the energized state is poor, water, sodium chloride solution, etc. are appropriately poured into the container 2.

After a lapse of a predetermined time, anions such as cyan having migrated to the anodes 5a and 5b are sucked up by the pump 10 together with water through the holes 21 provided in the anodes 5a and 5b, and discharged out of the container.

Similarly, the cations such as cadmium that have moved to the cathode 2 are sucked by the pump 6 together with water through the nonwoven fabric 8 or the gravel 9 and discharged out of the container.

The discharged water is subjected to a separate treatment such as pH adjustment for sedimentation or adsorption on activated carbon.

As described above, in the soil purification apparatus of this embodiment, the pollutants contained in the soil in the state of ions are first attracted to the electrodes, and then these ions are discharged by the pump. Therefore, pollutants in the soil can be removed efficiently.

Therefore, the contaminated soil can be treated so as not to affect the environment, and the treated soil can be reused.

Further, the concrete container required to store the contaminated soil or the chemicals required to prevent the elution of the pollutant becomes unnecessary.

In this embodiment, the container itself is formed as a cathode by forming the container with a conductive material and electrically connecting it to the negative side of the power source. However, the container is formed with a non-conductive material and a separate electrode is used. May be provided and used as a cathode.

In this case, a metal mesh or lath may be provided along the inner circumference of the container 2, and this may be used as the cathode.

In this embodiment, the nonwoven fabric is used as the filtering means, but the invention is not limited to such a form, and any form can be used as long as it can selectively separate water and ions from soil. . For example, the mesh or lath described above can also be used as the filtering means.

Further, in the present embodiment, the pump is used as the discharging means, but the pump may be omitted when the gravity is sufficient for the natural fall.

In particular, the pump may be omitted in the discharge means on the cathode side when the container is the cathode.

In this embodiment, no drain layer is provided between the non-woven fabric and the inner surface of the container. However, as shown in FIG. 3, the strainer pipe 31 is arranged between the non-woven fabric 8 and the inner surface of the container 2. Good.

Further, in the present embodiment, the discharging means for the ions collected on the anode side is structured so as to be sucked up by the pump, but it may be structured such that the ions are naturally dropped downward through the bottom of the container or sucked by the pump. Good.

In this embodiment, the anodes 5a and 5b are
Although the anode is provided with the function as the filtering means by being formed of the hollow conductive member having the holes, the anode and the filtering means may be separately configured. That is, the anode may be arranged inside the non-conductive strainer tube.

(Second Embodiment) FIG. 4 is a schematic sectional view of a soil purifying apparatus according to a second embodiment. The parts and the like that are substantially the same as those in the first embodiment are designated by the same reference numerals and the description thereof is omitted.

The soil purifying apparatus of the second embodiment is similar to the first embodiment in that it has a container 41 as a storage means capable of storing the soil 1.
And a positive electrode 5a, 5b electrically connected to the positive side of the power source 4 and a power source 4 for applying a voltage to the soil 1,
Is made of a conductive material and is adapted to act as a cathode by being electrically connected to the negative side of the power source 4.

The container 41 has a tapered lower portion than the upper portion, and has a lid 42 which is openable and closable at the bottom.

Inside the container 41, which is the cathode, a nonwoven fabric 8 as a filtering means capable of selectively permeating water and ions from the soil 1 is provided on the wall side of the container 41. Between them also acts as a drain layer. Similarly, gravel 9 as a filtering means is provided on the upper portion of the lid 42, and the gravel 9 also functions as a drain layer.

In the soil purifying apparatus of the second embodiment, cations such as mercury and cadmium gathered in the vicinity of the container 41, which is the cathode, are removed from the container 41 together with water through the drainage pipe 43 provided in the lid 42. It is designed to be discharged to.

Since the soil purifying apparatus of the second embodiment operates in substantially the same manner as in the first embodiment, detailed description thereof will be omitted. However, after removing contaminants from the soil, the lid 42 is placed at a predetermined place. It differs from the first embodiment in that the soil is opened and the soil is carried out from the container 41.

As described above, in the soil purifying apparatus of the second embodiment, as in the first embodiment, the pollutants contained in the soil in the state of ions are first attracted to the electrodes, and then these ions are Since it was sucked with a pump or allowed to fall naturally by gravity, contaminants in the soil can be removed efficiently.

Therefore, the concrete container required to store the contaminated soil or the chemical agent required to prevent the elution of the pollutant becomes unnecessary.

Further, the contaminated soil can be treated so as not to affect the environment, and the treated soil can be reused. In particular, in the second embodiment, the treated soil can be easily reused by opening the lid 42 at a desired position.

[0062]

As described above, the soil purifying apparatus of the present invention has the accommodating means capable of accommodating the soil containing predetermined ions and water, the power source capable of applying the predetermined voltage, and the electricity source. Since it is provided with an electrode composed of an anode and a cathode connected to each other and an ejecting means capable of ejecting the ions collected around at least one of the anode and the cathode together with the water to the outside of the accommodating means, contamination It becomes possible to remove pollutants from soil easily and quickly.

[0063]

[Brief description of drawings]

1A is a schematic vertical sectional view of a soil purifying apparatus according to a first embodiment, and FIG. 1B is a sectional view taken along line AA of FIG.

FIG. 2 is a detailed vertical sectional view of anodes 5a and 5b.

FIG. 3 is a horizontal sectional view of a soil purifying apparatus showing a modified example of the first embodiment.

FIG. 4 is a schematic vertical sectional view of a soil purifying apparatus according to a second embodiment.

[Explanation of symbols]

 1 Soil 2 Container (cathode) 3 Ion and water 4 Power supply 5a, 5b Anode 6 Pump (discharging means) 8 Nonwoven fabric (filtering means) 9 Gravel (filtering means) 10 Pump (discharging means) 21 Hole (filtering means) 31 Strainer pipe 41 container (cathode) 42 lid

Claims (6)

[Claims] 1. An accommodating means capable of accommodating soil containing predetermined ions and water, a power supply capable of applying a predetermined voltage, an electrode electrically connected to the power supply and comprising an anode and a cathode, the anode, and A soil purifying device comprising: a discharging unit capable of discharging the ions collected around at least one of the cathodes and the water together with the water. 2. The power source is capable of controlling a generated voltage below a predetermined value so that the ions do not substantially cause an electrode reaction at the interface between the electrode and the soil. Soil purification equipment. 3. The discharging means comprises a filtering means capable of selectively permeating water and ions contained in the soil.
The soil purification device described. 4. The soil purifying apparatus according to claim 3, wherein the filtering means is made of a conductive material and is used as the electrode. 5. The soil purifying apparatus according to claim 1, wherein the accommodating means is made of a conductive material and is used as the cathode. 6. A step of applying a predetermined voltage to a soil containing predetermined ions and water, a step of moving the ions to a predetermined area in the soil by the voltage, and the moved ions together with water in the soil. And a soil purification method for discharging the soil to purify the soil.