KR101652811B1 - A radioactive pollution soil decontamination system - Google Patents

Abstract

The present invention relates to a radioactively polluted soil decontamination system. More specifically, the present invention relates to a radioactively polluted soil decontamination system which separates a pebble and an organic material through a mesh and a blower, and only separates fine soil with high radioactive pollution, thereby increasing decontamination efficiency and a reduction rate of soil for reuse.

Description

The present invention relates to a radioactive contaminated soil decontamination system,

The present invention relates to a radioactive contaminated soil decontamination system, and more particularly, to a radioactive contaminated soil decontamination system that increases decontamination efficiency through micro-soil separation with high radioactive contamination and increases the reduction rate to reusable soil.

Generally, a large amount of radioactive soil is generated in the operation and decommissioning of a nuclear facility.

In particular, if unexpected accidents occur in a nuclear facility due to various reasons such as poor management and natural disasters, the surrounding soil may be contaminated by radionuclides emitted from nuclear facilities.

Soils contaminated with radioactive materials can directly damage plants and animals inhabited by humans and the land. In the second place, it is possible to pollute the ground water flowing in the soil, Can be adversely affected.

Recently, in order to reduce the amount of radioactive waste generated or to recover the soil contaminated with radionuclides in a short period of time, a soil decontamination technique for disposing the radioactive soil on its own has been developed.

The soil decontamination techniques include a method of immersing the soil using a polymer electrolyte complex and collecting the immobilized contaminated soil and a method of measuring the degree of contamination of the soil contaminated with the radioactive material, , The contaminated soil is transferred to a radioactive waste repository and stored for a long period of time or the radioactive contaminated soil is treated with a decontamination agent to remove the radionuclide from the contaminated soil.

At this time, if the measured radioactive material contamination level is at an extremely low level, it is an effective method to treat the contaminated soil in a radioactive waste repository without using long-term storage, and to convert it into a soil from which radioactive materials have been removed.

However, the conventional soil decontamination method has the following problems.

First, in the process of soil decontamination, a process of separating or decontaminating organic substances mixed in the soil, such as leaves, is not provided.

Second, the use of a chemical decontamination agent has a problem in that the cost of equipment for treating a waste liquid generated in the decontamination process is further increased.

Thirdly, the radioactive material is mainly adsorbed on the fine soil. Since it is difficult to separate the fine soil from the soil, it is difficult to effectively decontaminate the soil. Even the soil with low contamination level is disposed of, As compared with the case of the conventional method.

Korea Publication No. 10-2004-0074514

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above problems, and it is an object of the present invention to improve the decontamination efficiency of the soil and the reduction ratio to the reusable soil by separating the micro- To thereby provide a radioactive contaminated soil decontamination system that minimizes the generation of secondary wastes by the waste liquid.

In order to achieve the above object, the present invention provides a pretreatment filtration unit including a pretreatment filtration unit including a mesh for filtering soil in a contaminated area and a blower for spraying air toward an organic material filtered through the mesh, A drum screen set for spraying high-pressure water onto the soil passed through the drum screen and sorting the particle size of the soil, and spraying the soil and the waste liquid classified as small-sized particles through the drum screen set at a high pressure An ejector for removing contaminants on the surface of the soil through physical friction, a hydrocyclone set for re-classifying the particle size of the soil sprayed through the ejector, And a waste solution treatment unit for coagulating and sedimenting the soil so that the aggregated precipitate is dehydrated and treated as waste, An organic material composed of a water tank containing a soil and a waste liquid classified into those having a large particle size (more than 0.75 mm) through a screen set, and a mesh screen for filtering floating matters suspended in the upper part of the water tank through the supply of washing liquid to the water tank Wherein the ejector uses a water pressure of the waste liquid to wash away contaminants in the soil and to remove contaminants on the surface of the soil using physical friction between the soil, System.

At this time, the classification standard of the soil particle size classified by the drum screen set is 0.75 mm, and the classification standard of the soil particle size classified by the hydrocyclone set is 0.02 mm.

The contaminated soil is supplied to the pretreatment filtration unit through a conveyor, and a meter for measuring the radioactive contamination degree of the soil conveyed along the conveyor is installed at one side of the conveyor. The conveyor measures the degree of contamination of the soil through the meter, It is preferable that the direction is switched so that the soil is not introduced into the pre-filtration section.

The drum screen set may further include a first sorting part including a first drum screen having a filtration hole and a first washing part, and a filter for sorting the particle size of the soil having passed through the filtering hole of the first sorting part to 0.75 mm or less And a second sorting portion including a second drum screen having a hole and a second washing portion.

The hydrocyclone set includes a first cyclone accommodating the soil and waste fluid flowing through the ejector and classifying the particle size of the soil into a large particle and a small particle, The soil classified as having a large particle size through the first cyclone is filtered through the screen into the reusable soil, and the soil having a particle size exceeding 0.02 mm through the second cyclone is sandwiched between the second cyclone and the second cyclone, After passing through a dehydrator, it is preferable to reduce the waste to a reusable soil or to treat it as waste through radioactive contamination measurement.

In addition, the waste liquid treatment unit may include a reaction tank containing a soil and a waste liquid classified as small particle size through a hydrocyclone set, and including a stirrer for stirring the soil and the waste liquid, A dewatering device for dewatering the coagulated sludge in the settling tank and treating the sludge as waste, a dewatering device for storing dewatered water from the dewatering device, And a treatment water tank for reusing it as a washing solution or discharging it to the environment through filtration.

The radioactive contaminated soil decontamination system according to the present invention has the following effects.

First, gravel and organic matter are first separated through a mesh and a blower before washing the soil, thereby improving the efficiency of the decontamination operation.

In other words, since radioactive contaminants are not adsorbed on large-sized objects such as pebbles mixed with soil, it is not necessary to reduce the efficiency of the work by performing cleaning work. Therefore, organic matters such as leaves are removed from the soil The efficiency of the decontamination operation can be improved by separating the soil through the blower for spraying air, because the efficiency may be deteriorated in sorting the particle size of the soil.

Second, the effect of soil decontamination can be enhanced by removing the contaminants on the soil surface through physical friction of the ejector ejecting the soil and water at high pressure.

Particularly, it is possible to maximize the amount of reducing the remaining soil to the reusable soil by separating the soil that has been decontaminated through the ejector through the hydrocyclone and separating only the highly contaminated fine soil again.

Third, in the process of initially supplying the soil to be decontaminated, the presence of radioactive contamination of the soil is measured in advance through a meter installed on the conveyor, thereby preventing the inefficiency of unintentionally cleaning uncontaminated soil.

Fourthly, in washing and classification of contaminated soil, washing and classification of soil are performed only by using water, thereby minimizing the generation of waste liquid.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 shows a system for decontaminating a radioactive contaminated soil according to a preferred embodiment of the present invention.

It is to be understood that the words or words used in the present specification and claims are not to be construed in a conventional or dictionary sense and that the inventor can properly define the concept of a term in order to describe its invention in the best possible way And should be construed in light of the meanings and concepts consistent with the technical idea of the present invention.

Hereinafter, a system for decontaminating a radioactive contaminated soil according to a preferred embodiment of the present invention will be described with reference to FIG.

The radioactive contaminated soil decontamination system has a technical feature that can classify soil particle size more finely by physical classification by mesh and blower, classification by water specific gravity, classification by hydrocyclone.

That is, as the particle size of the soil is smaller, the adsorption rate of the radioactive contaminants is higher. Since the fine soil having a small particle size can be classified by the washing and the classification of the particles several times as described above, it is possible to increase the reduction rate of the soil, It can be maximized.

The radioactive contaminated soil decontamination system includes a conveyor 100, a pretreatment filtration unit 200, a drum screen set 300, an ejector 400, a hydrocyclone set 500, a waste liquid treatment unit 600, .

The conveyor 100 serves to automatically transfer the soil supplied from the soil to be decontaminated, that is, the area where radioactive contamination is expected, to the pretreatment filtration unit 200.

The soil is preferably supplied in ton back, and the supplied soil falls through the hopper (H) to the conveyor (100).

Since the conveyor 100 corresponds to the pre-treatment filtration unit 200, the soil conveyed along the conveyor 100 is automatically supplied to the pre-treatment filtration unit 200.

At this time, a meter 110 for measuring the degree of radioactive contamination may be further provided on the upper side of the conveyor 100.

The meter 110 measures the radioactive contamination degree of the soil conveyed along the conveyor 100. When the soil on the conveyor 100 is measured to have a low radioactive contamination degree (reusable degree) through the meter 110, 100 so that the soil does not flow into the pre-filtration unit 200 through the switching of the conveying direction.

This is because the soil range to be decontaminated is wide, so that there is a large amount of uncontaminated soil, so that the uncontaminated soil is filtered before washing to enhance the efficiency of the decontamination operation.

Although not shown, the conveyor 100 is configured to be redirected so that uncontaminated soil is transferred to a separate location without being introduced into the pre-treatment filtration unit 200, and immediately returned to the general environment.

Next, the pretreatment filtration unit 200 serves to primarily filter out soil or organic matter having a large particle size among the soil supplied through the conveyor 100.

That is, the soil is composed of various particle sizes, and the supplied soil may contain not only gravel and stones but also organic matter such as leaves, tree roots, tree branches, etc., It is classified.

The pre-filtration unit 200 includes a mesh 210 and a blower 220.

The mesh 210 is configured to filter out organic matter such as pebbles and leaves having a large particle size, and the size of the filtration hole of the mesh 210 is preferably 30 mm.

Thus, the gravel and organic matter contained in the soil supplied from the conveyor 100 are primarily filtered on the mesh 210.

The blower 220 is configured to blow the organic matter filtered on the mesh 210 to a separate processing site, and is configured to inject air.

That is, by transporting the organic matter on the mesh 210 to another site through the blower 220, gravel and organic matter having a large particle size are reclassified.

Next, the drum screen set 300 cleans the soil filtered through the pretreatment filtering unit 200, that is, the soil dropped through the mesh 210, and at the same time, functions to sort the particle size of the soil.

That is, the soil dropped through the pretreatment filtration unit 200 is transferred to the drum screen through water pressure, and the soil is cleaned and classified by the agitation by the screen rotation and the high-pressure spraying of the cleaning liquid in the drum will be.

At this time, the drum screen set 300 is preferably composed of a first sorting part 310 and a second sorting part 320 so that sorting of the soil can be finely performed.

The first sorting part 310 includes a first washing part 311 for spraying water at a high pressure and washing the soil filtered through the pretreatment filtration part 200 with a particle size of 30 mm or less, And a first drum screen 312.

At this time, the size of the filtration hole of the first drum screen 312 is preferably 3 mm.

That is, the soil is classified into a particle size of 3 mm or less through the first sorting part 310 and sent to the second sorting part 320.

The second sorting part 320 includes a second washing part 321 for spraying water to the soil filtered with a particle size of 3 mm or less through the first sorting part 310 at a high pressure and washing the soil, And a second drum screen 322 for re-sorting the drum.

At this time, the size of the filtration hole of the second drum screen 322 is preferably 0.75 mm.

Meanwhile, the washing waste liquid generated in the process of washing and sorting the soil through the drum screen set 300 is re-transferred to the first sorting part 310 and the second sorting part 320 through the pump, It is preferable to be reused in the process.

On the other hand, the soil whose particle size is classified as larger than 3 mm through the drum screen set 300 is transferred to the organic material separation tank 350.

The organic material separating tank 350 serves to reuse the soil after re-washing the soil after receiving the soil having a particle size of more than 3 mm through the soil having low radioactive contamination, that is, the drum screen set 300.

In detail, the organic material separating tank 350 separates the organic matter suspended in the upper part of the water tank through the washing liquid, through the mesh, and the soil having a particle size of more than 3 mm is separated from the washing liquid through a separate screen, .

On the other hand, the soil separated to a particle size of 0.75 mm or less through the drum screen set 300 is accommodated in a waste solution collecting tank 360 provided separately.

The waste liquid collecting tank 360 is provided with an ejector 400 and the soil waste liquid collected in the liquid collecting tank 360 is transported through the ejector 400 to a hydron cyclone set 500 to be described later.

The ejector 400 is configured to eject soil and waste liquid settled in the waste liquid collecting tank 360 at a high pressure to remove contaminants on the surface of the soil through physical friction.
The ejector has a technical feature that the contaminants on the surface of the soil are washed away by using the water pressure of the waste liquid and the contaminants on the surface of the soil are peeled off by physical friction between the soil.

Next, the hydrocyclone set 500 functions to finely sort the soil classified by the drum cyclone set 300 through the hydrocyclone method.

That is, the particle size of the soil is physically classified through the mesh 210, the blower 220, and the drum screen set 300, and then the fine soil is classified by the hydrocyclone method.

In general, according to research papers published so far, the particle size of the fine soil having a high degree of adsorption of radioactive contaminants is 0.02 mm or less. The mesh size 210 of the drum 210 and the drum screen set 300 alone are 0.75 mm, so that the micro-soil having high radioactive contamination can be classified through the hydrocyclone set 500.

The hydrocyclone set 500 is preferably composed of a first cyclone 510 and a second cyclone 520 in order to increase the particle size distribution efficiency of the soil.

The first cyclone 510 recycles the soil and the waste liquid injected through the ejector 400 of the pulp collecting tank 360 through the hydrocyclone method.

At this time, the particle size standard of the soil to be classified is 0.075 mm.

That is, the soil having a particle size of 0.075 mm or less through the first cyclone 510 is transferred to a separate first cyclone storage tank 511, and the soil having a particle size exceeding 0.075 mm is separated from the washing liquid through a separate screen Which is then reduced to reusable soil.

It is preferable that the washing waste liquid generated in this process is transferred to the waste liquid collecting tank 360 and reused.

The second cyclone 520 serves to recycle the soil classified into 0.075 mm or less through the first cyclone 510 and receives the soil and the waste liquid from the first cyclone storage tank 511.

The second cyclone 520 re-classifies the soil having a particle size of 0.075 mm or less through the hydrocyclone method, wherein the particle size standard of the soil to be classified is 0.02 mm.

That is, soil having a particle size of less than 0.02 mm classified through the second cyclone (520) is classified into the most contaminated micro-soil, and the soil having a particle size of more than 0.02 mm is measured for radioactive contamination Treated or reused soil.

In order to perform such a process, the soil classified to a particle size of 0.02 mm or less in the second cyclone 520 is transferred to the even tank 530, and the soil classified to a particle size exceeding 0.02 mm is transferred to the storage tank 540 do.

Thereafter, the soil transferred to the storage tank 540 is dehydrated through a dewatering device F, and then made into a soil cake. If the radioactive contamination degree of the soil cake is higher than the reference value, the soil is disposed of. do.

At this time, the dewatering device F is preferably a filter press, and the purified water in the dewatering process is transferred to the organic material treatment tank 350 and reused.

On the other hand, the soil transferred to the equalization tank 530 and having a particle size of 0.02 mm or less is conveyed to a waste liquid treatment unit 600 to be described later as an object of disposal.

Next, the waste liquid treatment unit 600 serves to dispose of the soil having a particle size of 0.02 mm or less, and receives the waste liquid and the soil accommodated in the equal tank 530.

The waste liquid treatment unit 600 includes a reaction tank 610, a sedimentation tank 620, and a treatment tank 630. The waste water treatment unit 600 collects and precipitates the fine soil contained in the waste liquid,

The reaction tank 610 carries a process for coagulating and precipitating the fine soil by transferring the fine soil having a particle size of 0.02 mm or less from the even tank 530 and introducing the flocculation precipitant into the reaction tank 610.

That is, when the waste liquid containing the reference amount of fine soil is filled in the reaction tank 610, the coagulating sedimentant is introduced, and in the reaction tank 610, a stirring operation for increasing the reaction between the fine soil in the waste liquid and the flocculating agent .

For this purpose, it is preferable that a stirrer 611 is installed in the reaction tank 610.

The sedimentation tank 620 is a structure in which the flocculation and sedimentation reaction of the waste liquid mixed with the flocculant and sediment is activated.

That is, the waste liquid in the reaction tank 610 is mixed with the flocculating agent through the stirrer 611, and then is retained for a predetermined time, and then transferred to the settling tank 620 to activate the coagulation sedimentation reaction.

Thereafter, the coagulated sediment is subjected to a dehydration process through a filter press (F), and the dehydrated waste is transferred to a separate waste treatment site and then treated.

The treatment water tank 630 receives the purified water in the settling tank 620 and the filter press F and the purified water collected in the treatment water tank 630 is reused as a cleaning solution of the decontamination system, Environment.

This completes the decontamination process for the contaminated soil.

As described above, the radioactive contaminated soil decontamination system according to the present invention has a technical feature in that the particle size of the contaminated soil is classified into fine soil, and the soil is washed using only water to minimize the generation of waste liquid.

Particularly, it is possible to separate decontamination work by separating soil and organic matter by using mesh and blower, and it is possible to separate only fine soil with high radioactive contamination through hydrocyclone method, so that the amount of soil reduced to general environment can be increased do.

That is, through a series of processes, it is possible to sort only the micro-soil having a high radioactive contamination degree, so that the treatment of the soil with low radioactive contamination degree can be minimized.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art.

100: Conveyor 110: Meter
200: Pretreatment filtering unit 210: Mesh
220: Blower 300: Drum screen set
310: first sorting part 311: first washing part
312: first drum screen 320: second sorting section
321: second washing section 322: second drum screen
350: organic matter separation tank 360: waste water collection tank
400: Ejector 500: Hydrocyclone set
510: first cyclone 511: first cyclone storage tank
520: second cyclone 530:
540: Storage tank 600: Waste liquid treatment unit
610: Reactor 611:
620: Settling tank 630: Treatment tank
400: Ejector

Claims (6)

A pretreatment filtration part including a mesh for filtering soil in the contaminated area and a blower for spraying air toward the organic material filtered through the mesh;
A drum screen set for spraying high-pressure water onto the soil passed through the mesh of the pretreatment filtration unit to clean the soil and classify the particle size of the soil;
An ejector for spraying the soil and the waste liquid having passed through the drum screen set to a small particle size at a high pressure to remove contaminants on the surface of the soil through physical friction;
A hydro cyclone set for reclassifying the particle size of the soil sprayed through the ejector;
And a waste liquid treatment unit for coagulating and sedimenting the soil classified as small particle size through the hydrocyclone set and dehydrating the aggregated precipitate to treat the waste as waste,
A water tank for receiving the soil and the waste liquid classified into those having a large particle size (more than 0.75 mm) through the drum screen set, a mesh for filtering the suspended matters floating on the water tank through the supply of the washing liquid to the water tank, Further comprising a configured organic material separation vessel,
The ejector
Wherein the pollutants on the surface of the soil are washed away by using the water pressure of the waste liquid and the contaminants on the surface of the soil are peeled off by physical friction between the soil. delete delete The method according to claim 1,
The drum screen set includes:
A second drum screen having a filtration hole for re-sorting the particle size of the soil having passed through the filtration hole of the first fractionation section to 0.75 mm or less; And a second sorting part including a second washing part. The method according to claim 1 or 4,
Wherein the hydrocyclone set comprises:
A first cyclone accommodating the soil and the waste liquid introduced through the ejector and classifying the particle size of the soil into a large particle and a small particle, a second cyclone for classifying the particle size of the soil classified as small through the first cyclone to less than 0.02 mm Lt; / RTI >
The soil classified as having a large particle size through the first cyclone is filtered through a screen and reduced to a reusable soil. The soil having a particle size exceeding 0.02 mm through the second cyclone is passed through a dehydrator, Characterized in that it is reduced to soil or treated with waste. The method according to claim 1 or 4,
Wherein the waste liquid processing unit comprises:
A reaction tank containing a soil and a waste liquid classified as small particle sizes through a hydrocyclone set and including an agitator for agitating the soil and the waste liquid, and activating coagulation sedimentation through the introduction of the flocculating agent;
A sedimentation tank in which coagulated sediment introduced from the reaction tank is flocculated and separated into sludge and water;
A dewatering device for dehydrating the coagulated sludge in the settling tank and treating it as waste;
And a treatment water tank for storing dehydrated water from the dehydrating apparatus and discharging the dehydrated water to the environment through reuse or filtration of the dehydrated water.

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