JP6008522B2 - Decontamination method for contaminated soil - Google Patents

Description

  The present invention relates to a decontamination method for contaminated soil, in which soil contaminated with radioactive substances is decontaminated.

  When treating soil contaminated with chemical substances, the contaminated soil is excavated and disposed of by industrial waste, or purified using quick lime or microorganisms. It has also been proposed to excavate contaminated soil, sandwich the contaminated soil with a sheet-like chemical substance adsorbent, and cover it with uncontaminated soil (see, for example, Patent Document 1).

  However, since the technique disclosed in Patent Document 1 is a technique assuming purification of contaminated soil, it is fundamental to treat soil contaminated with specific impurities such as radioactive substances. The current situation is that it cannot be resolved.

JP 2010-253420 A

  The present invention has been made in view of the above situation, and provides a decontamination treatment method for contaminated soil that can adsorb a radioactive substance that is a specific pollutant and decontaminate soil contaminated with the radioactive substance. The purpose is to do.

The method for decontamination of contaminated soil of the present invention according to claim 1 for achieving the above object is a method for decontamination of contaminated soil, in which radioactive soil contains decontaminated soil containing surface soil. Removing the surface soil containing radioactive material to expose the upper soil surface, removing the upper soil surface of the upper soil surface to expose the lower soil surface, and having an adsorbing component material that adsorbs the radioactive material A component material is laid on the lower soil surface, and the upper soil layer is composed of a first upper soil layer on the upper layer side and a second upper soil layer on the lower layer side, and is exposed by removing the upper soil layer on the upper soil surface. The lower soil surface is a second lower soil surface which is exposed after removing the first upper soil surface after removing the first upper soil surface of the upper soil surface and after removing the second upper soil layer of the first lower soil surface. Yes, the adsorbing component material is laid on the second lower soil surface, and the surface layer is formed on the adsorbing component material Backfilling, with backfill the first overburden on the surface soil was backfilled, characterized in that backfilling the second overburden above the backfilled first overburden.

In the present invention according to claim 1, since the adsorbing component material having the adsorbing component material that adsorbs the radioactive material is laid on the lower soil surface, the surface soil is backfilled, and the upper soil is backfilled thereon, The radioactive material can be adsorbed to the adsorbing component material material under. For this reason, it becomes possible to decontaminate soil contaminated with radioactive substances by adsorbing radioactive substances as specific pollutants. Moreover, even if rain or the like soaks into the soil, the radioactive substance is not adsorbed by the adsorbing component material, so that the radioactive substance does not enter the groundwater.
And since the soil is backfilled in the order of the surface soil, the first upper soil that existed on the upper layer side, the second upper soil that existed on the lower layer side on the adsorbing component material material having the adsorbing component material, The surface soil containing the radioactive substance can be backfilled in the lower layer of the plurality of layers, and the radioactive substance can be adsorbed by the adsorbing component material.

Moreover, the decontamination processing method of the contaminated soil of the present invention according to claim 2 is the decontamination processing method of contaminated soil according to claim 1 , after the surface soil is backfilled on the adsorbing component material, Furthermore, an adsorbing component material is laid and the first upper layer soil is backfilled on the adsorbing component material.

In this invention which concerns on Claim 2 , surface soil can be pinched | interposed with an adsorption component material material.

Moreover, the decontamination processing method of the contaminated soil of this invention which concerns on Claim 3 is a decontamination processing method of the contaminated soil of Claim 1 or Claim 2 WHEREIN: The said adsorption component substance material is a sheet-like support | carrier. The adsorbing component material that adsorbs the radioactive substance is an adsorbing component material sheet material that is physically fixed.

In the present invention according to claim 3 , by using the adsorbing component material sheet material, the adsorbing component material material can be arranged in a sheet of an arbitrary area, and since it is a sheet material, it is necessary to collect it. Even in this case, it can be easily recovered.

Moreover, the decontamination processing method of the contaminated soil of the present invention according to claim 4 is the decontamination processing method of contaminated soil according to claim 3 , wherein the adsorbing component material of the adsorbing component material sheet material is coal ash. The adsorbing component material sheet material is characterized in that the zeolite is adhered and fixed to the carrier with a binder.

In the present invention according to claim 4 , radioactive material (for example, radioactive cesium) can be adsorbed and decontaminated using artificial zeolite derived from coal ash.

  The method for decontamination of contaminated soil according to the present invention makes it possible to decontaminate soil contaminated with radioactive substances by adsorbing radioactive substances that are specific pollutants.

It is a conceptual diagram of the contaminant adsorption sheet used for the decontamination processing method of the contaminated soil which concerns on one Example of this invention. It is process drawing explaining the example of preparation of a contaminant adsorbing sheet. It is a graph explaining an example of the contaminant adsorption | suction performance of a zeolite. It is process explanatory drawing of the decontamination processing method of the contaminated soil which concerns on one Example of this invention. It is process explanatory drawing of the decontamination processing method of the contaminated soil which concerns on one Example of this invention.

  The adsorbing component material sheet material as the adsorbing component material material used in the decontamination treatment method of the contaminated soil of this example applies a sheet-like cloth as a carrier, and the adsorbing component material is a zeolite (artificial material) derived from coal ash. Zeolite) is bonded to cloth. And the decontamination processing method of contaminated soil carries out the decontamination process of the radioactive cesium etc. of the contaminated soil contaminated by the radioactive substance (radiocesium etc.) as a specific pollutant with the zeolite of the adsorption component substance sheet material. .

  The contaminant adsorbing sheet used in the decontamination processing method of the present invention will be specifically described with reference to FIGS.

  FIG. 1 illustrates a concept of a contaminant adsorbing sheet according to an embodiment of the present invention, FIG. 2 illustrates a process for explaining an example of creating a contaminant adsorbing sheet to which a solid adsorbing component substance is applied, and FIG. The graph explaining an example of pollutant adsorption | suction performance is shown.

  As shown in FIG. 1, a solid adsorbing component substance 2 is physically fixed on the surface of a cloth sheet 1 that is a sheet-like carrier, and a contaminant adsorbing sheet 3 is configured. As the adsorbing component substance 2, for example, an artificial zeolite that adsorbs radioactive cesium, which is a contaminant, is used. As the adsorbing component substance 2 in the solid state, activated alumina, vermiculite, coal ash, chestnut, hydrotalcite, natural zeolite and the like are applied. Depending on the type of the adsorbing component substance 2, radioactive cobalt, radioactive strontium, radioactive iodine and the like are adsorbed as contaminants.

  A procedure for creating the contaminant adsorbing sheet 3 will be described with reference to FIG.

  As shown in FIG. 2 (a), the adhesive 5 is applied to the surface of the cloth sheet 1, and as shown in FIG. 2 (b), the necessary amount of solid particles / powder on the surface to which the adhesive 5 has been applied. The adsorbing component material 2 is sprinkled, sprinkled, sprayed, etc., and the adsorbing component material 2 is adhered (physically fixed) to the surface of the cloth sheet 1 by the adhesive 5. Thereby, as shown in FIG. 2 (c), the cloth sheet 1 whose surface is covered with the adsorbing component substance 2 is created and used as the contaminant adsorbing sheet 3.

  The test results of the adsorption performance of zeolite (adsorption component substance 2) will be described with reference to FIG.

  The results shown in FIG. 3 show that the adsorbing component substance 2 (zeolite) is stirred in 20 mL of test water (Cs, Sr, Co, I having a concentration of 50 ppm), and a part of the test water is passed after a certain period of time. This is a result of measuring the concentration of Cs (◯), Sr (●), Co (Δ), and I (▲). As shown in the figure, it can be seen that the adsorbing component substance 2 using zeolite mainly adsorbs Cs (◯) and I (▲) as contaminants. That is, it can be seen that Cs which is a specific contaminant can be mainly adsorbed by using the contaminant adsorbing sheet 3 to which the adsorbing component material 2 (artificial zeolite) is fixed.

  The Example of the decontamination processing method of the contaminated soil of this invention implemented using the contaminant adsorption sheet 3 based on FIG. 4, FIG. 5 is demonstrated. FIG. 4 shows a process of excavation / removal until the contaminant adsorbing sheet 3 is laid, and FIG. 5 shows a process of refilling the excavated soil on the contaminant adsorbing sheet 3.

  As shown in FIGS. 4A and 4B, the surface soil 30 of the contaminated soil containing the contaminant (radioactive material or the like) is removed, and the upper soil surface 32 of the upper soil 31 is exposed. The upper layer soil 31 includes a first upper layer soil 33 on the upper layer side and a second upper layer soil 35 on the lower layer side. As shown in FIG. 4C, the first upper soil layer 33 of the upper soil layer 31 is excavated and removed, and the first lower soil surface 34 of the second upper soil layer 35 is exposed. As shown in FIG. 4 (d), the second upper layer soil 35 is excavated and removed to expose the second lower soil surface 36 as the lower soil surface, and the contaminant adsorbing sheet 3 is placed on the second lower soil surface 36. Lay down.

  As shown in FIG. 5A, the contaminated soil surface layer 30 is backfilled on the contaminant adsorbing sheet 3, and the contaminant adsorbing sheet 3 is laid on the surface soil 30. As shown in FIG. 5 (b), the first upper layer soil 33 existing on the upper layer side of the upper layer soil 31 is backfilled on the contaminant adsorbing sheet 3, and the second upper layer soil 35 existing on the lower layer side of the upper layer soil 31. Is backfilled on the first upper layer soil 33. That is, backfilling is performed so that the second upper layer soil 35 existing on the lower layer side of the upper layer soil 31 becomes the surface soil.

  Therefore, the surface soil 30 of the contaminated soil containing the pollutant (radioactive material, etc.) is sandwiched between the contaminant adsorbing sheets 3 and below the upper layer soil 31 composed of the second upper layer soil 35 and the first upper layer soil 33. Backfilled. For this reason, the radioactive material of the surface soil 30 is adsorbed by the contaminant adsorbing sheet 3 below the upper soil 31, and decontamination is performed, and disposal such as transporting the surface soil 30 to another place as waste is performed. It becomes possible to decontaminate the contaminated soil without any problem, and the problem of waste treatment in the decontamination treatment of the contaminated soil can be solved.

  And since the contaminated soil containing pollutants (radioactive substances etc.) exists in a deep position from the ground surface, the radiation dose on the ground surface can be greatly reduced. In addition, since the presence of radioactive substances is deep from the ground surface, even if crops such as agricultural crops are cultivated on the ground surface, the effects of radiation do not affect the crops, making it possible to grow crops safely. Become.

  Moreover, even if rain or the like soaks into the upper soil 31, the contaminant adsorbing sheet 3 prevents radioactive substances and the like from entering the groundwater. In addition, since the radioactive material etc. can be disposed by collecting the contaminant adsorbing sheet 3, even if it is necessary to treat the radioactive material etc. separately, by collecting the contaminant adsorbing sheet 3, It becomes possible to respond safely and easily.

  In the embodiment described above, an example in which the contaminant adsorbing sheet 3 is applied as the adsorbing component material has been described. However, between the second lower soil surface 36 and the surface soil 30 of the contaminated soil (and the surface soil of the contaminated soil). It is also possible to lay the adsorbing component substance 2 (artificial zeolite) directly at a necessary position between the upper layer soil 30 and the first upper layer soil 33).

  The above-described decontamination method for contaminated soil makes it possible to decontaminate the contaminated soil without disposing of the surface soil 30 as a waste and transporting it to another place. It becomes possible to decontaminate soil contaminated with radioactive substances by adsorbing substances.

  INDUSTRIAL APPLICATION This invention can be utilized in the industrial field | area of the decontamination processing method of the contaminated soil which decontaminates the soil contaminated with the radioactive substance.

DESCRIPTION OF SYMBOLS 1 Cloth sheet 2 Adsorption component substance 3 Contaminant adsorption sheet 30 Surface soil 31 Upper soil 32 Upper soil surface 33 First upper soil 34 First lower soil surface 35 Second upper soil 36 Second lower soil surface

Claims (4)

A decontamination method for contaminated soil, in which radioactive soil contains decontaminated soil containing surface soil,
Remove the surface soil containing radioactive material to expose the upper soil surface,
Removing the upper soil of the upper soil surface to expose the lower soil surface,
An adsorbing component material having an adsorbing component material that adsorbs radioactive material is laid on the lower soil surface,
The upper soil is composed of a first upper soil on the upper layer side and a second upper soil on the lower layer side,
The lower soil surface exposed by removing the upper soil of the upper soil surface is
The first lower soil surface is exposed after removing the first upper soil layer of the upper soil surface, and the second lower soil surface is exposed after removing the second upper soil layer of the first lower soil surface,
Laying the adsorbing component material on the second lower soil surface,
Backfill the surface soil on the adsorbing component material,
Backfilling the first upper soil on the surface soil that has been backfilled,
A decontamination treatment method for contaminated soil , wherein the second upper soil layer is backfilled on the backfilled first upper soil layer . In the decontamination processing method of the contaminated soil of Claim 1 ,
After the surface soil is backfilled on the adsorbing component material, the adsorbing material material is further laid and the first upper soil is backfilled on the adsorbing material material. Decontamination processing method. In the decontamination processing method of the contaminated soil according to claim 1 or claim 2 ,
The adsorbing component material is
A decontamination method for contaminated soil, characterized in that it is an adsorbent component material sheet material in which an adsorbent component adsorbing a radioactive substance is physically fixed on a sheet-like carrier. In the decontamination processing method of the contaminated soil of Claim 3 ,
The adsorbing component material of the adsorbing component material sheet material is a zeolite derived from coal ash,
The method for decontamination treatment of contaminated soil, wherein the adsorbing component material sheet material has the zeolite bonded and fixed to the carrier with a binder.

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