JP2014081278A - Manufacturing method for adsorption device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method for adsorption device capable of easily treating radioactive cesium-containing water during its treatment.SOLUTION: A manufacturing method for an adsorption device 1 that is supplied with radioactive cesium-containing water A and that internally houses an adsorbent 4 adsorbing radioactive cesium comprises the steps of: determining an adsorption amount of radioactive cesium adsorbed on the adsorbent 4; calculating a ratio of a first material and a second material that include the adsorption amount determined in the determination step, in the adsorbent 4 including the first material adsorbing radioactive cesium and the second material that has radioactive cesium-adsorbing capacity lower than that of the first material or has no such capacity; and mixing the first material and the second material at the ratio calculated in the calculation step to fill the inside of a main unit.

Description

  The present invention relates to a method for manufacturing an adsorption device.

  JP, 2004-45371, A (patent documents 1) is mentioned as a method of processing radioactive cesium content water containing radioactive cesium, for example. In Patent Document 1, in a method for treating a liquid containing a radionuclide generated in a nuclear power plant, the liquid is passed through one or more adsorbents capable of adsorbing the radionuclide contained in the liquid. Is disclosed. Moreover, according to the processing method of patent document 1, it is disclosed that a radionuclide can be removed efficiently and the radioactive level in a plant can be reduced.

JP 2004-45371 A

  In the processing method disclosed in Patent Document 1, radioactive cesium can be removed from the radioactive cesium-containing water by adsorbing radioactive cesium to the adsorbent. However, the present inventor has noted that the following demands that have not been disclosed in the above-mentioned Patent Document 1 have recently occurred.

  As in the above-mentioned Patent Document 1, in a nuclear power plant, it has been considered that the radionuclide is efficiently removed. Therefore, the radionuclide adsorbed on the adsorbent becomes a high concentration, the radiation dose rate increases, and the radionuclide is increased. The workers who removed the garments wore protective clothing and required special measures. However, in recent years, the number of workers who treat radioactive cesium-containing water has increased, and it is desired that workers can easily handle this treatment.

  The final disposal method of the adsorbent differs depending on the concentration of the adsorbent adsorbed radioactive cesium. Since Patent Document 1 is a method for treating radionuclides in a nuclear power plant, the concentration of radioactive cesium to be adsorbed on the adsorbent is high, making it difficult to handle. For this reason, it is desired to make the adsorbent adsorbed with radioactive cesium easier to handle after desired final disposal.

  This invention makes it a subject to provide the manufacturing method of the adsorption | suction apparatus which can make it easy to handle when processing radioactive cesium containing water in view of the said problem.

  The method for producing an adsorbing device of the present invention is a method for producing an adsorbing device in which radioactive cesium-containing water containing radioactive cesium is supplied, and an adsorbing material that adsorbs radioactive cesium is contained therein, and the adsorbing material is radioactive. A step of determining an adsorption amount for adsorbing cesium; a first substance that adsorbs radioactive cesium; and a second substance that has a lower ability to adsorb radioactive cesium than the first substance or does not adsorb radioactive cesium In the adsorbent, the step of calculating the ratio of the first substance and the second substance responsible for the adsorption amount determined in the determining step, and the ratio of the first substance and the second substance calculated in the calculating step. A step of mixing the two substances and filling the inside of the main body.

  According to the method for manufacturing an adsorption tower of the present invention, in the calculating step, the first substance that adsorbs a relatively large amount of radioactive cesium as the adsorbent in the calculating step so as to have the adsorption amount determined in the determining step; In the step of calculating and filling the ratio of the second substance that does not adsorb radioactive cesium more than the first substance, the first substance and the second substance are mixed at that ratio. An adsorption device capable of controlling the amount of cesium can be manufactured. For this reason, it is possible to control the adsorption amount that is easy to handle when the worker treats the radioactive cesium-containing water, and to control the adsorption amount that is easy to handle when the adsorbent adsorbing the radioactive cesium is finally disposed of. it can. As described above, the present invention can control the amount of the radioactive cesium that is adsorbed by the adsorbent, and thus provides a method for manufacturing an adsorption device that can be easily handled when treating radioactive cesium-containing water. be able to.

  Preferably, in the manufacturing method of the adsorption apparatus, in the calculating step, a substance that does not adsorb radioactive cesium is used as the second substance, and in the calculating step, the amount of adsorption by which the first substance adsorbs radioactive cesium is determined. And a step of calculating a ratio of the adsorption amount of the first substance to the adsorption amount determined in the determining step.

  Thereby, it is possible to easily calculate the mixing ratio of the first substance and the second substance out of the adsorption amount for adsorbing the radioactive cesium on the adsorbent.

  As described above, according to the present invention, it is possible to provide a method for manufacturing an adsorption device that can be easily handled when processing radioactive cesium-containing water.

It is a schematic diagram which shows the adsorption | suction apparatus in Embodiment 1 of this invention, and the processing method of radioactive cesium containing water. It is a figure which shows the adsorption isotherm of a bitumen. It is a schematic diagram which shows the processing apparatus and processing method of radioactive cesium containing water of Embodiment 2 of this invention. It is another schematic diagram which shows the processing apparatus and processing method of radioactive cesium containing water of Embodiment 2 of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following drawings, the same or corresponding parts are denoted by the same reference numerals, and description thereof will not be repeated.

(Embodiment 1)
As shown in FIG. 1, the adsorption device 1 in the present embodiment is also called an adsorption tower, and includes a supply unit 2, a discharge unit 3, and an adsorbent 4. The supply unit 2 supplies radioactive cesium-containing water A containing radioactive cesium to the inside. The discharge unit 3 discharges the treated water B from which radioactive cesium has been reduced by the adsorbent 4 to the outside. In the present embodiment, the supply unit 2 is formed on the upper side and the discharge unit 3 is formed on the lower side. However, the present invention is not particularly limited to this configuration, and the supply unit 2 is formed on the lower side and the discharge unit 3 is formed on the upper side. It may be formed.

  The adsorbent 4 is accommodated inside the main body of the adsorption device 1 and adsorbs radioactive cesium in the radioactive cesium-containing water.

  The adsorbent 4 includes a first substance and a second substance. The first substance adsorbs radioactive cesium. The second substance has a lower adsorption ability of radioactive cesium than the first substance or does not adsorb radioactive cesium.

  Here, the adsorption ability of radioactive cesium means that the adsorption amount of radioactive cesium is high.

  The adsorbent 4 is configured to control the amount of radioactive cesium adsorbed on the adsorbent 4 by mixing the first substance and the second substance. Such a configuration can be realized, for example, by controlling the amounts of the first and second substances accommodated in the main body of the adsorption apparatus 1 in view of the radioactive cesium adsorption ability of the first and second substances. .

  Here, the amount adsorbed by the adsorbent 4 and the first and second substances (adsorption amount) means the amount of radioactive cesium per unit weight, and is expressed in units of Bq / kg.

  For example, ferrocyanide is used as the first substance, and glass beads and / or plastic beads are used as the second substance. As another example, ferrocyanide is used as the first substance and activated carbon is used as the second substance. As yet another example, a ferrocyanide is used as the first substance, and a chelate resin is used as the second substance. As yet another example, ferrocyanide is used as the first example, and zeolite and / or sand is used as the second material.

  The adsorbent 4 is not particularly limited as long as two or more kinds of substances having different radioactive cesium adsorption capacities are mixed so as to control the adsorption amount (Bq / kg) of radioactive cesium. Adsorption of radioactive cesium Three or more kinds of substances having different abilities may be mixed. In addition, each of the first and second substances may include two or more kinds of substances having the same adsorption capacity.

  Then, the manufacturing method of the adsorption | suction apparatus 1 in this Embodiment is demonstrated.

  First, an adsorption amount for adsorbing radioactive cesium on the adsorbent 4 is determined. In this step, a desired amount of adsorption can be arbitrarily determined for various reasons such as economy and radiation dose rate. Further, a desired amount of adsorption may be determined in consideration of the wall thickness of the adsorption device main body.

  However, in this process, an amount lower than the amount of radioactive cesium adsorbed when a substance having the highest adsorption capacity of radioactive cesium among the substances constituting the adsorbent 4 is filled at a rate of 100% is used as the amount of adsorption. decide.

  Next, the proportion of the first substance and the second substance that bears the determined adsorption amount is calculated. That is, the ratio between the amount adsorbed by the first substance and the amount adsorbed by the second substance out of the amount adsorbed by the adsorbent 4 is calculated.

  In this step, when a substance that does not adsorb radioactive cesium is used as the second substance, the first substance determines the amount of adsorption by which the radioactive cesium is adsorbed, and the first amount relative to the adsorption amount determined in the determining step. Calculating a ratio of the amount of adsorption of the substance. That is, by calculating the adsorption amount of the first substance with respect to the adsorption amount determined in the determining step, the ratio of the first substance in the adsorbent 4 (= adsorption amount of the first substance / determined adsorption amount). Is calculated.

  Next, the first substance and the second substance are mixed at the ratio calculated in the calculating step, and the first and second substances are filled into the inside of the adsorption apparatus main body.

  Hereinafter, an example of the manufacturing method of the adsorption device 1 will be described. Assume that bitumen is used as the first substance and a substance that does not adsorb radioactive cesium is used as the second substance.

  First, the process of determining the amount of radioactive cesium to be adsorbed on the adsorbent 4 will be described.

  First, the shielding effect is determined from the material and thickness of the adsorption device. For example, the main body of the adsorption device is made of iron and the wall thickness is 5 cm. The attenuation factor C2 / C1 of iron is obtained from the equation C2 / C1 = 1 / EXP (μt). Here, t is the thickness of iron, and μ is the attenuation coefficient of the shield. In this case, it is obtained as shown in Table 1 below.

  Therefore, the iron attenuation rate C2 / C1 is calculated to be about 0.14 (= 1 / (EXP (0.393 × 5)).

  Next, the allowable radiation dose rate of the adsorbent 4 is obtained. For example, when the radiation dose per hour allowed on the outer surface of the adsorption device 1 is 250 μSv / h, the acceptable radiation dose rate of the adsorbent 4 is 1 / 0.14 × 250 = 1.79 mSv / h.

  Next, the allowable adsorption amount to be adsorbed by the adsorbent is determined from the shape of the adsorber and the properties of the adsorbent. The radioactive cesium adsorbed in the adsorption device is affected by the adsorbent itself, surrounding water, and the radiation direction of radiation in the device, and the amount of radiation emitted from the device to the outside of the device is attenuated. Radiated (for example, most of the radiation emitted from radioactive cesium located in the center of the device is attenuated by the surrounding water and the wall of the adsorption device and is not emitted outside the device. A part of the radiation emitted from the radioactive cesium located in (1) is transmitted through the wall of the adsorption device and released outside the device). Therefore, the amount of radioactive cesium to be adsorbed on the adsorbent is determined from the allowable radiation dose rate obtained above, the shape of the adsorber, and the properties of the adsorbent. In the present embodiment, the amount of radioactive cesium to be adsorbed on the adsorbent 4 is set to 2 million Bq / kg, for example.

  Next, a process of calculating the ratio of the first substance and the second substance that bear the adsorption amount determined in the determining process in the adsorbent 4 including the first substance and the second substance will be described.

  First, the concentration of non-radioactive cesium and radioactive cesium in water containing radioactive cesium is measured. For example, the concentration of non-radioactive cesium is 1 mg / L, and the concentration of radioactive cesium is 10,000 Bq / L (concentration of radioactive cesium / concentration of non-radioactive cesium = 10,000 Bq / mg).

Next, the equilibrium adsorption amount of non-radioactive cesium with respect to the concentration of non-radioactive cesium contained in the radioactive cesium-containing water is determined. Specifically, as shown in FIG. 2, the adsorption isotherm of non-radioactive cesium of bitumen is obtained, and the amount of non-radioactive cesium adsorbed on bitumen (= 7.3087 × (1 mg / L) ^0.4743 = 7.3 mg / g -Bitumen = 7300 mg / kg-bitumen). In FIG. 2, q means the amount of non-radioactive cesium adsorbed at equilibrium, and Cs means the concentration of non-radioactive cesium.

In addition, the adsorption isotherm shown in FIG. 2 was calculated | required as follows.
200 mL of a stock solution in which cesium chloride was dissolved in pure water so as to be 10 mg / L was placed in a 500 mL flask. To this stock solution, bitumen was added at 0.01, 0.1, 1 and 10 g / L. Bitumen was added and the flask was shaken with a constant temperature shaker at 20 ° C. and 160 rpm for 24 hours. After shaking for 24 hours, the stock solution was filtered through a 0.1 μm filter, and the concentration of cesium was measured by ICP-MS. This measured value was taken as the concentration of cesium at equilibrium. Further, the equilibrium adsorption amount was calculated by dividing the value obtained by subtracting the equilibrium concentration from the concentration of cesium in the stock solution by the concentration of the adsorbent added.

  Since the ratio of radioactive cesium and non-radioactive cesium in the radioactive cesium-containing water is the same as the ratio of adsorption, the amount of radioactive cesium adsorbed on the adsorbent is calculated. Specifically, the adsorption amount of radioactive cesium per 1 kg of bitumen is 7300 mg / kg-bitumen × 10,000 Bq / mg = 73 million Bq / kg.

  Next, the ratio of the first substance is calculated as 2 million Bq / kg ÷ 73 million Bq / k = 2.74%. Thereby, in the adsorbent 4, the ratio of bitumen as the first substance is 2.74%, and the ratio of the non-adsorbent that does not adsorb radioactive cesium as the second substance is calculated to be 97.26%. Is done.

Next, 2.74% of the first substance and 97.26% of the second substance are mixed and filled in the main body of the adsorption device. Thereby, adsorption device 1 can be manufactured.
Note that the first substance and the second substance are preferably mixed uniformly in the adsorption device 1. When the uneven mixing of the first substance and the second substance in the adsorption device 1 is reduced, it is possible to suppress a portion having a large amount of radioactive cesium adsorption in the adsorption device 1. In this case, since the concentration of the radioactive cesium to be adsorbed is controlled as a whole in the adsorption device 1 and it is possible to suppress the formation of a place where the radiation dose is partially high, it is possible to make the handling difficult by an operator. Can be reduced. Therefore, by uniformly mixing the adsorbent, the radiation device can be controlled by reducing the bias of the radiation dose as much as possible in each part of the adsorption device 1 while controlling the radiation dose as a whole. be able to.

  Then, the processing method of the radioactive cesium containing water in this Embodiment is demonstrated. In this Embodiment, radioactive cesium containing water is processed by adsorbing radioactive cesium from the radioactive cesium containing water A using the adsorption | suction apparatus 1 shown in FIG.

  First, radioactive cesium-containing water A is supplied from the supply unit 2 of the adsorption device 1. The radioactive cesium-containing water A is not particularly limited as long as it contains radioactive cesium, and may further contain other components such as organic substances and heavy metals.

  Next, the radioactive cesium-containing water A is adsorbed on the adsorbent 4. In this step, a first substance that adsorbs radioactive cesium and a second substance that has a lower radioactive cesium adsorption capacity than the first substance or does not adsorb radioactive cesium are mixed and adsorbed on the adsorbent 4. Control the amount of radioactive cesium.

  Next, the radioactive cesium is adsorbed by the adsorbent 4 so that the treated water B in which the radioactive cesium is reduced is discharged from the discharge unit 3. Thereby, the radioactive cesium containing water A can be processed in the state in which the adsorption amount of the radioactive cesium was controlled in the adsorbent 4.

  As described above, the method for treating radioactive cesium-containing water A in the present embodiment supplies the radioactive cesium-containing water A containing radioactive cesium to the adsorption device 1 that accommodates the adsorbent 4 therein, and thus radioactive cesium. In the method of treating the radioactive cesium-containing water A by adsorbing the adsorbent 4 to the adsorbent 4, the adsorbent 4 has a first substance that adsorbs the radioactive cesium as the adsorbent 4, and the ability to adsorb radioactive cesium more than the first substance. The amount of radioactive cesium adsorbed on the adsorbent 4 is controlled by mixing with a second substance that does not adsorb low or radioactive cesium.

  The adsorption device 1 of the present embodiment includes an adsorbent 4 accommodated therein, and is supplied with radioactive cesium-containing water A containing radioactive cesium so that the adsorbent 4 adsorbs radioactive cesium. As the adsorbent 4, a first substance that adsorbs radioactive cesium and a second substance that has a lower radiocesium adsorption capacity than this first substance or does not adsorb radioactive cesium are mixed and adsorbed on the adsorbent 4. It is configured to control the amount of radioactive cesium to be adsorbed.

  The manufacturing method of the adsorption device 1 of the present embodiment is a manufacturing method of the adsorption device 1 in which the radioactive cesium-containing water A containing radioactive cesium is supplied and the adsorbent 4 that adsorbs the radioactive cesium is accommodated therein. , A step of determining an adsorption amount for adsorbing radioactive cesium on the adsorbent 4, a first substance that adsorbs radioactive cesium, and a first substance that has a lower adsorption ability of radioactive cesium than the first substance or does not adsorb radioactive cesium In the adsorbent 4 containing the two substances, the first substance and the second substance that bear the adsorption amount determined in the determining step, and the ratio calculated in the calculating step A step of mixing the substance and the second substance and filling the inside of the main body.

  The method for controlling the amount of adsorption of radioactive cesium according to the present embodiment includes a first substance that adsorbs radioactive cesium as adsorbent 4, and an adsorbing capacity of radioactive cesium that is lower than that of the first substance or adsorbs radioactive cesium. The amount of radioactive cesium adsorbed on the adsorbent 4 is controlled by mixing with a second substance that does not.

  According to the method for treating radioactive cesium-containing water, the adsorption device 1, the method for producing the adsorption device 1, and the method for controlling the amount of adsorption of radioactive cesium according to the present embodiment, the first substance that adsorbs a relatively large amount of radioactive cesium and The amount of radioactive cesium adsorbed on the adsorbent 4 is controlled by mixing with a second substance that does not adsorb radioactive cesium more than the first substance. For this reason, it is possible to control the adsorption amount that is easy to handle when the worker treats the radioactive cesium-containing water, and to control the adsorption amount that is easy to handle when the adsorbent adsorbing the radioactive cesium is finally disposed of. it can. Therefore, since the amount of adsorption is large, the adsorption device itself can be prevented from becoming a high-concentration contaminant and difficult to handle. In a nuclear power plant, it is considered that as much radioactive cesium as possible is adsorbed by an adsorption device. In the present embodiment, the amount of adsorbing radioactive cesium on the adsorbent 4 can be controlled. Therefore, handling can be facilitated when treating radioactive cesium-containing water.

  Preferably, in the manufacturing method of the adsorption device 1 of the present embodiment, in the calculation step, a substance that does not adsorb radioactive cesium is used as the second substance, and in the calculation step, the first substance adsorbs radioactive cesium. And a step of calculating a ratio of the adsorption amount of the first substance to the adsorption amount determined in the determining step.

  Thereby, the mixing ratio of the 1st substance and the 2nd substance which bears the adsorption amount which makes the adsorbent 4 adsorb | suck radioactive cesium can be calculated easily.

  Preferably, in the manufacturing method of the adsorption device 1 of the present embodiment, the determining step includes a step of obtaining an attenuation rate from the material of the main body, a step of obtaining an allowable radiation dose rate of the adsorbent 4, and an allowable adsorption amount. Determining.

  Thereby, the amount of radioactive cesium adsorbed to be adsorbed on the adsorbent can be determined in consideration of the shielding effect from the material and thickness of the main body portion of the adsorption device 1.

Preferably, in the method for treating radioactive cesium-containing water, the adsorption device 1, the method for producing the adsorption device 1, and the method for controlling the amount of adsorption of radioactive cesium according to the present embodiment, ferrocyanide is used as the first substance. Features. Examples of the ferrocyanide include iron ferrocyanide, cobalt ferrocyanide, nickel ferrocyanide, and the like. Among these, ferrocyanide (bituminous) is preferable from the viewpoint of handling and cost. Bitumen is also called ferrocyanide (C ₁₈ Fe ₇ N ₁₈ ) or Prussian blue, and includes materials derived from bitumen such as bitumen-supported products and bitumen granules.

  Since ferrocyanide can adsorb radioactive cesium efficiently, when the adsorbent 4 contains a large amount of ferrocyanide, it can be controlled so that the amount of adsorption increases, so that the amount of adsorption can be easily controlled.

  Preferably, in the method for treating radioactive cesium-containing water, the adsorption device 1, the method for producing the adsorption device 1, and the method for controlling the amount of adsorption of radioactive cesium, ferrocyanide is used as the first substance, and as the second substance, Glass beads and / or plastic beads are used.

Ferrocyanide can adsorb radioactive cesium efficiently, and glass beads and plastic beads do not adsorb radioactive cesium. For this reason, it becomes easier to control the amount of adsorption on the adsorbent 4 by mixing ferrocyanide having a high adsorption capacity with glass beads and / or plastic beads. Moreover, since glass beads and plastic beads are inexpensive, the cost can be reduced and the amount of adsorption can be controlled more easily.
Furthermore, since glass beads and plastic beads can be easily processed with a small difference from the specific gravity (apparent specific gravity) and / or particle diameter of the ferrocyanide, the uniformity of the first and second substances in the adsorption apparatus 1 is increased. Can be mixed. For this reason, the uniformity of the radioactive cesium adsorb | sucked in the adsorbent 4 can be improved. Accordingly, handling of radioactive cesium-containing water can be facilitated.

  Here, Table 2 shows the radiation dose rate according to the ratio when bitumen is used as the first substance and glass beads and / or plastic beads are used as the second substance.

  As shown in Table 2, since the amount of radioactive cesium adsorbed on the adsorbent can be controlled by changing the ratio of bitumen, the radiation dose rate can be controlled. When the ratio of bitumen is 5%, the radiation dose rate is the same as when only zeolite is used.

  In the method for treating radioactive cesium-containing water, the adsorption device 1, the method for producing the adsorption device 1, and the method for controlling the amount of adsorption of radioactive cesium in the present embodiment, preferably, ferrocyanide is used as the first substance, It is characterized by using activated carbon as a substance.

  Ferrocyanide can adsorb radioactive cesium efficiently, and activated carbon can adsorb organic matter. Therefore, when the radioactive cesium-containing water further contains an organic substance, the amount of radioactive cesium adsorbed can be controlled and the organic substance can be treated.

  In the method for treating radioactive cesium-containing water, the adsorption device 1, the method for producing the adsorption device 1, and the method for controlling the amount of adsorption of radioactive cesium in the present embodiment, preferably, ferrocyanide is used as the first substance, A chelate resin is used as the substance.

  Ferrocyanide can adsorb radioactive cesium efficiently, and chelate resin can adsorb heavy metals. Therefore, when the radioactive cesium-containing water further contains a heavy metal, the amount of radioactive cesium adsorbed can be controlled and the heavy metal can be treated.

  In the method for treating radioactive cesium-containing water of the present embodiment, the adsorption device 1, the method for producing the adsorption device 1, and the method for controlling the amount of adsorption of radioactive cesium, preferably, ferrocyanide is used, and the second substance is zeolite and It is characterized by using sand.

Ferrocyanide can adsorb radioactive cesium efficiently, and zeolite and sand can adsorb a little radioactive cesium, although the adsorption ability of radioactive cesium is lower than ferrocyanide. For this reason, also in such a structure, since the adsorption amount of radioactive cesium can be controlled as the adsorbent 4 as a whole, handling can be facilitated when processing radioactive cesium-containing water. Further, by using zeolite and sand, it is possible to reduce unevenness in the amount of adsorption in the adsorption device as compared with the case of using glass beads or the like.
Further, zeolite and sand have a small difference between specific gravity (apparent specific gravity) and particle diameter when bitumen is used as ferrocyanide (for example, specific gravity difference is 0.2, particle diameter difference is 0.4 to 0.4). 3 mm), the first and second substances can be mixed with high uniformity in the adsorption device. For this reason, the uniformity of the radioactive cesium adsorb | sucked in the adsorbent can be improved. Accordingly, handling of radioactive cesium-containing water can be facilitated.

(Embodiment 2)
This Embodiment demonstrates the method and apparatus which process the radioactive cesium containing water discharged | emitted when processing the fly ash using the processing method and adsorption apparatus 1 of the radioactive cesium containing water of Embodiment 1. FIG.

  As shown in FIG. 3, the processing apparatus 10 in this Embodiment is the mixing tank 7, the solid-liquid separation apparatus 8, the adjustment tank 11, the sedimentation tank 12, the turbidity removal apparatus 13, and the pressurizing part 14. , A reverse osmosis (RO) membrane device 15, an adsorption device 1, a capturing unit 17, a shielding unit 18, a treated water tank 19, and a solidifying device 20.

  The mixing tank 7 is supplied with fly ash C containing radioactive cesium and water D, and mixes the fly ash C and water D to form a slurry. The mixing tank 7 dissolves radioactive cesium in the fly ash C in water D. The water D is not particularly limited, and for example, tap water, industrial water, pure water, ground water, reprocessed water for various types of waste water, and the like can be used.

  The mixing tank 7 may have a stirring member for mixing and stirring the supplied fly ash C and water D. The mixing tank 7 may include a plurality of tanks.

  The solid-liquid separation device 8 is connected to the mixing tank 7 and performs solid-liquid separation on the slurry obtained in the mixing tank 7. The solid-liquid separator 8 is configured to separate the slurry into washed fly ash (washed fly ash E) and separated water containing radioactive cesium. The solid-liquid separator 8 includes, for example, a filter press or a belt press.

  Devices such as a cleaning device and a classification device may be arranged between the mixing tank 7 and the solid-liquid separation device 8 (not shown).

  The adjustment tank 11 is connected to the separated water discharge unit of the solid-liquid separator 8 and stores the separated water containing radioactive cesium generated by the solid-liquid separator 8. The adjustment tank 11 may include a plurality of tanks.

  The sedimentation tank 12 is connected to the adjustment tank 11 and coagulates and precipitates coarse solids in the separated water (coarse solids than separated by the turbidizer 13) when the solids are mixed in the separated water. The sedimentation tank 12 reduces coarse solids in the separated water. The sedimentation tank 12 may include a plurality of tanks.

  The turbidity removal device 13 is connected to the sedimentation tank 12 and is used for filtering the separated water in which coarse solids are reduced. The turbidity removal device 13 is coarser than the RO membrane, that is, impurities (rougher than separating with the RO membrane) For example, it is a pretreatment device for the RO membrane device 15. The turbidity removing device 13 is, for example, sand filtration.

  The pressurizing unit 14 is connected to the turbidity device 13 and pressurizes the separated water from which coarse impurities discharged from the turbidity device 13 are removed to an osmotic pressure or higher. The pressurizing unit 14 is, for example, a high pressure pump.

  The RO membrane device 15 is connected to the pressurizing unit 14, supplied with pressurized separated water, and generates permeated water F and concentrated water by RO membrane treatment. The permeated water F is water that has passed through the RO membrane, and the concentrated water is water that does not pass through the RO membrane and contains radioactive cesium. In this RO membrane device 15, the permeated water F from which radioactive cesium has been removed and the concentrated water in which the radioactive cesium contained in the fly ash remains are obtained by filtration with an RO membrane.

  The RO membrane device 15 includes, for example, an RO membrane and a pressure vessel that accommodates the RO membrane. The RO membrane is configured not to transmit radioactive cesium.

  In addition, the processing apparatus 10 may be provided with one set of the pressurizing part 14 and the RO membrane apparatus 15, and may be provided with a plurality of sets of the pressurizing part 14 and the RO membrane apparatus 15. When the processing apparatus 10 includes a plurality of sets of pressure units 14 and RO membrane apparatuses 15, they may be arranged in parallel or in series, but are preferably arranged in series.

  The use of the permeated water F obtained by the RO membrane device 15 is not particularly limited, but is preferably configured to be supplied to the solid-liquid separation device 8. For example, as shown by a dotted line connecting the permeated water F and the solid-liquid separator 8 in FIG. 3, the permeate discharge unit of the RO membrane device 15 and the solid-liquid separator 8 are connected by a pipe or the like. When the solid-liquid separator 8 includes a filter press or a belt press, the permeated water F is used for cleaning the fly ash C. Moreover, you may use the permeated water F as the water D which wash | cleans the fly ash C, for example. Thus, it is preferable that the processing apparatus 10 is configured to circulate water generated in the processing apparatus 10 in the processing apparatus 10.

  The adsorption device 1 is the same as that described in Embodiment 1 shown in FIG. 1 and is connected to the concentrated water discharge unit of the RO membrane device 15. Since the radioactive cesium in the concentrated water is adsorbed by the adsorbent by the adsorption device 1, treated water is generated.

  The capturing unit 17 is disposed on the outlet side of the adsorption device 1 and captures the adsorbent 4 such as ferrocyanide leaked from the adsorption device 1. Although the capture unit 17 is not particularly limited, for example, a device having a filter such as a UF membrane device or an MF membrane device, a precipitation device, or the like can be used, and at least of the UF membrane device and the MF membrane device from the viewpoint of high capture properties. Either one is preferably used. The UF membrane device or MF membrane device includes, for example, a UF membrane or MF membrane that can capture the adsorbent 4 and a pressure vessel that accommodates the UF membrane or MF membrane.

  Moreover, it is preferable that the processing apparatus 10 is provided with a pipe that connects the discharge tank that discharges the non-permeated water captured in the capture unit 17 and the adjustment tank 11. By this piping, the non-permeated water obtained by the capture unit 17 can be returned to the adjustment tank 11, so that it is possible to prevent the adsorbent 4 that has adsorbed radioactive cesium from flowing out of the processing apparatus 10.

  The shielding unit 18 surrounds the adsorption device 1 and the capturing unit 17. The shielding part 18 is, for example, concrete and is configured so that radioactive cesium does not leak from the inside to the outside. More specifically, the shielding unit 18 blocks radiation emitted from the adsorption device 1 and the capture unit 17 in which radioactive cesium is concentrated, and even if concentrated water containing radioactive cesium flows out, the treatment is performed. Radiation is prevented from leaking out of the apparatus 10.

  The treated water tank 19 is connected to the capture unit 17 and stores treated water from which the adsorbent 4 has been removed by the capture unit 17. The treated water stored in the treated water tank 19 is reduced in radioactive cesium, but has a salt content.

  The solidification device 20 is connected to the treated water tank 19 and separates into treated water G with reduced salinity and salinity H. The solidification device 20 is, for example, an evaporation device. The treated water G obtained may be supplied to the solid-liquid separation device 8 or used as the water D for washing the fly ash C, similarly to the permeated water F.

  Next, a method for treating fly ash in the present embodiment will be described. The fly ash cleaning method and the processing method in the present embodiment are performed using the fly ash treatment apparatus 10 shown in FIG.

  First, fly ash C containing radioactive cesium and water D are supplied to the mixing tank 7, and the fly ash C and water D are mixed in the mixing tank 7 to form a slurry. In this step, radioactive cesium in fly ash C is dissolved in water D.

  Next, the slurry is subjected to solid-liquid separation to form separated water. In this step, it is preferable to solid-liquid separate the slurry using a filter press or a belt press. By this process, it is separated into washed fly ash (washed fly ash E) as a solid content and separated water containing radioactive cesium as a liquid content.

  In addition, you may implement other processes, such as a classification process and a dehydration process, between the process of forming a slurry, and the process of forming isolation | separation water.

  By carrying out the above steps, radioactive cesium in the fly ash C can be reduced, so that the fly ash C can be washed.

  Next, the separated water containing radioactive cesium obtained by solid-liquid separation is transferred to the adjustment tank 11.

  Next, the separated water stored in the adjustment tank 11 is transferred to the settling tank 12, and when the separated water contains solids, the solids in the separated water are coagulated and precipitated.

  Next, the separated water that has been precipitated in the settling tank 12 is filtered by the turbidity device 13. By this filtration, coarse impurities such as solid substances in the separated water that have not been removed in the precipitation tank 12 can be removed.

  The sedimentation tank 12 and the turbidity removal device 13 may be omitted. In this case, the separated water obtained by the solid-liquid separation device 8 is supplied to the RO membrane device 15 through the pressurizing unit 14 as it is.

  Next, the separated water from which coarse impurities have been removed by the turbidizer 13 is pressurized by the pressure unit 14. The pressure applied to the separated water is not particularly limited, but a pressure necessary to obtain the permeated water F from which radioactive cesium has been removed by the RO membrane device 15 is applied.

  Next, the separated water pressurized by the pressurizing unit 14 is supplied to the RO membrane device 15 and separated into permeated water F and concentrated water by RO membrane treatment using the RO membrane. Through this step, permeated water F from which radioactive cesium has been removed and concentrated water in which radioactive cesium contained in fly ash C remains are generated.

  In addition, the pressurizing unit 14 and the RO membrane device 15 may be one stage or a plurality of stages. In the case of two stages, the separated water pressurized by the first-stage pressurizing unit 14 is filtered by the first-stage RO membrane device 15, and the resulting permeated water is added by the second-stage pressurizing part. It is preferable to filter the pressurized permeated water with a second-stage RO membrane device and use the water that has permeated through the second-stage RO membrane device as permeated water F.

  The permeated water F may be discharged to the outside of the processing apparatus 10, but it is preferable to employ a closed system that circulates water generated in the processing apparatus 10 into the processing apparatus 10. In the closed system, when the solid-liquid separator 8 is a filter press or a belt press, the permeated water F may be supplied to the filter press or the belt press as a cleaning liquid, or may be used as the water D.

  Next, the concentrated water formed by the solid-liquid separation device 8 is supplied to the adsorption device 1, and the radioactive cesium in the concentrated water is adsorbed on the adsorbent. That is, concentrated water containing radioactive cesium is supplied to the adsorption device 1 and the adsorbent 4 accommodated in the adsorption device 1 adsorbs the radioactive cesium. By this step, the radioactive cesium contained in the fly ash C can be adsorbed to the adsorbent 4. In this step, since the amount of radioactive cesium adsorbed on the adsorbent 4 is controlled, a predetermined waste treatment (final disposal assumed in advance) according to the amount of adsorption is performed.

  Next, the adsorbent 4 such as ferrocyanide leaked from the adsorption device 1 is captured. In this process, the adsorbent 4 such as ferrocyanide may leak from the adsorber 1 as fine powder or particles having a small particle diameter, but the adsorbent 4 adsorbing radioactive cesium is leaked from the adsorber 1. In the case that the adsorbent 4 is captured, the capturing unit 17 captures the adsorbent 4. The adsorbent adsorbing the radioactive cesium captured by the capture unit 17 is subjected to a predetermined waste treatment.

  In this capturing step, it is preferable to capture the adsorbent using at least one of the UF membrane device and the MF membrane device as the capture unit 17. In this case, the UF membrane and the MF membrane are used, for example, by a cross flow method.

  When at least one of the UF membrane device and the MF membrane device is used as the capture unit 17 in this process, the UF membrane and the MF membrane are used up to the vicinity of the withstand voltage, and the used UF membrane and the MF membrane are regenerated (washed). Instead, it is preferable to dispose by incineration processing, industrial waste processing, acceptance into an intermediate storage facility, or the like.

  The non-permeated water captured by the capture unit 17 is preferably returned to the adjustment tank 11. Thereby, it is possible to prevent the adsorbent 4 that has adsorbed radioactive cesium from flowing out of the processing apparatus 10.

  The step of adsorbing to the adsorbent 4 and the step of capturing the adsorbent 4 are performed in a shielding unit 18 that shields radiation inside. Thereby, it can suppress that radioactive cesium leaks outside during implementation of the above-mentioned process.

  By performing the above process, the concentrated water (radiocesium containing water) obtained by wash | cleaning the radioactive cesium contained in the fly ash C can be processed.

  Next, the treated water from which the adsorbent has been removed by the capture unit 17 is accommodated in the treated water tank 19. The treated water stored in the treated water tank 19 is reduced in radioactive cesium, but has a salt content.

  Next, the salt content in the treated water is separated by a solidifying device 20 such as an evaporator. Thereby, the treated water G with reduced salinity and the salinity H can be generated. The treated water G may be supplied to the solid-liquid separator 8 or used as the water D.

  As described above, the radioactive cesium-containing water treatment apparatus 10 in the present embodiment mixes the fly ash C containing radioactive cesium and the water D to form a slurry, and the slurry is solidified. A solid-liquid separation device 8 that forms a separated water by liquid separation, an RO membrane device 15 that is supplied with this separated water and generates permeated water F and concentrated water by RO membrane treatment, and this concentrated water is radioactive cesium-containing water. The adsorption apparatus 1 of Embodiment 1 shown in FIG.

  Further, the method for treating radioactive cesium-containing water in the present embodiment includes a step of mixing fly ash C containing radioactive cesium and water D to form a slurry, and separating the slurry by solid-liquid separation. FIG. 1 shows a step of forming water, a step of supplying this separated water to the RO membrane device 15 to generate permeated water F and concentrated water by RO membrane treatment, and this concentrated water as radioactive cesium-containing water. And a process of processing by the processing method of Embodiment 1.

  According to the method and apparatus 10 for treating radioactive cesium-containing water in the present embodiment, the amount of radioactive cesium adsorbed on the adsorbent can be controlled in the adsorber 1, so that it adheres to the fly ash C as radioactive cesium. Handling can be facilitated when treating the washed water of radioactive cesium. Like this Embodiment, the manufacturing method of the adsorption apparatus 1 of Embodiment 1 can be used as an adsorption apparatus in the cleaning of fly ash.

  In addition, in this Embodiment, although the pressurization part 14 and RO membrane apparatus 15 are arrange | positioned in the front | former stage of the adsorption | suction apparatus 1, you may arrange | position in the back | latter stage of the capture part 17 (not shown). In this case, after the step of capturing the adsorbent by the capturing unit 17, the step of pressurizing the treated water by the pressurizing unit 14 is performed, and then the RO membrane processing using the RO membrane is performed in the RO membrane device 15. To separate permeate and concentrated water. The concentrated water discharged from the RO membrane device 15 is water in which, for example, sodium chloride, potassium chloride, calcium chloride or the like is concentrated. In the case of this order of steps, the pressurizing unit 14 and the RO membrane device 15 are not contaminated by radioactive cesium, so that contaminated equipment can be reduced.

  Here, in this Embodiment, although the concentrated water which wash | cleaned the fly ash C was mentioned as an example as radioactive cesium containing water, the manufacturing method of the adsorption | suction apparatus 1 of this invention is the wash water of the fly ash C. It is not specifically limited to the manufacturing method of an adsorption | suction apparatus. As the radioactive cesium-containing water of the present invention, for example, leachate containing radioactive cesium generated from a landfill, a landfill site, etc., or wastewater obtained by treating soil containing radioactive cesium can be used. In this case, as shown in FIG. 4, the adjustment tank 11 is used as a receiving tank, and leachate is supplied to the adjustment tank 11. Further, the permeated water F may be returned to the adjustment tank 11.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above-described embodiment but by the scope of claims, and is intended to include all modifications within the meaning and scope equivalent to the scope of claims.

  DESCRIPTION OF SYMBOLS 1 Adsorption device, 2 Supply part, 3 Discharge part, 4 Adsorbent, 7 Mixing tank, 8 Solid-liquid separation apparatus, 10 Processing apparatus, 11 Adjustment tank, 12 Precipitation tank, 13 Turbidity removal apparatus, 14 Pressurization part, 15 RO Membrane device, 17 capture unit, 18 shielding unit, 19 treated water tank, 20 solidification device, A radioactive cesium-containing water, B, G treated water, C fly ash, D water, E washed fly ash, F permeated water, H salt content.

Claims (2)

Radioactive cesium-containing water containing radioactive cesium is supplied, and is a method of manufacturing an adsorbing device that contains therein an adsorbent that adsorbs radioactive cesium,
Determining an adsorption amount for adsorbing radioactive cesium on the adsorbent;
In the adsorbent comprising a first substance that adsorbs radioactive cesium and a second substance that has a lower adsorption ability of radioactive cesium than the first substance or does not adsorb radioactive cesium, the determination is performed in the determining step. Calculating a ratio of the first substance and the second substance that bear the adsorption amount;
A method of manufacturing an adsorption device, comprising: mixing a first substance and a second substance at a ratio calculated in the calculating step and filling the inside of the main body. In the calculating step, a substance that does not adsorb radioactive cesium is used as the second substance,
The calculating step includes
Obtaining an adsorption amount by which the first substance adsorbs radioactive cesium;
The method for manufacturing an adsorption device according to claim 1, further comprising: calculating a ratio of the adsorption amount of the first substance to the adsorption amount determined in the determining step.

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