JPS59184899A - Method of treating and volume-decreasing decomposition solution of sulfur-containing radioactive organic waste - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Technical Field of the Invention 1] The present invention relates to a method for treating a decomposed liquid obtained by oxidatively decomposing radioactive sulfur-containing (Ikukai Tomono) generated in facilities handling radioactive materials such as nuclear power generation facilities. 3, and a method for reducing and solidifying the volume of a sulfur-containing waste containing sulfur.

[Technical background of the invention and its problems 1 A variety of radioactive solid wastes are generated in facilities that handle radioactive materials such as nuclear power plants, but most of them are subject to final disposal methods. Because they are static and fluid, the main components of solid waste, such as used ion exchange resin A3 and Hinoirter sludge, are stored as they are in C tanks, etc. Abandoned 9! Reducing the amount of waste generated is considered to be an even more urgent and important issue than storage management.

Among such solid wastes, radioactive organic wastes such as used radioactive ion exchange resins are generated in large quantities, so reducing the volume of this waste greatly contributes to reducing the amount of wastes generated.

By the way, radioactive organic waste is a high-molecular compound, and it is possible to decompose it chemically to reduce its volume.
Volume reduction methods such as chemical decomposition methods have been tested.

Among these, the dry incineration method is a method in which the incineration process is literally incinerated in an incinerator, and many methods have been studied and developed.
There is. However, when incinerating radioactive organic materials in an incinerator, it is necessary to roll them into a heating stove.
It is necessary to devise pre-treatments such as drying and the method of supplying the resin.
The problem is that the operation and equipment are complicated - Also, since the incinerator itself does not have a function to suppress the scattering of incinerated ash, the scattering of radioactive incinerated ash from the incinerator is extremely large (DF: decontamination factor is Almost 1). In addition, since harmful gases such as SOx and NOx are generated as radioactive gases as incineration gas, contact treatment called waste gas treatment is necessary, including measures against radioactivity.
Moreover, these scum are highly corrosive, and there are problems such as difficulty in selecting A-sized devices. Furthermore, this method
When radioactive organic matter is processed in a high-temperature ring embankment, radioactive components migrate into the generated incineration gas, a problem unique to the handling of radioactivity: so-called nuclide migration. There is.

Also, wet incineration method uses water? A method of burning radioactive organic materials by pumping oxygen or air under high temperature and pressure of 20 to 100 atm and 200''300'c in a liquid or an aqueous copper sulfate solution. In addition to point E, there is point 1, which is that the volume reduction rate is several steps lower than the dry incineration method described above.

Furthermore, the pyrolysis method is a method in which the supply of oxygen is cut off and the radioactive organic matter is thermally decomposed. However, this method requires an extra step of burning the decomposition residue, and, like the dry incineration method, there is the problem of radionuclide migration.

On the other hand, the chemical decomposition method oxidizes and decomposes the resin through a chemical reaction with a drug, and the following methods are known.

(2) A method in which radioactive organic matter is carbonized with hot concentrated sulfuric acid (13o~300'C) and then oxidized and decomposed with nitric acid or hydrogen peroxide.

■ A method of oxidizing and decomposing organic waste by contacting it with hydrogen peroxide in a solution containing mainly iron ions, chromate ions, or dichromate ions.

(2) A method in which gas containing oxygen is injected under pressure at a temperature of 200-300' C1 pressure, 20-1000 atmospheres.

However, in these methods, f+M salt is generated as secondary waste due to neutralization of sulfate ions derived from sulfur-containing organic wastes such as cation exchange resins having sulfone groups and mixed ion exchange resins. , the temperature of the waste liquid is high, and the volume reduction effect when solidified is insufficient.

[Object of the Invention] The present invention has been made in order to address the above-mentioned conventional circumstances, and it is possible to reduce the openness of waste liquid by removing even inorganic ions under easy-to-implement and mild conditions. It is an object of the present invention to provide a method cl'3 for treating a radioactive sulfur-containing organic waste decomposition solution and a volume reduction solidification method that achieve a high volume reduction rate when solidified.

Summary of the Invention In other words, the present invention converts a liquid containing sulfate ions obtained by oxidative decomposition of radioactive sulfur-containing organic waste into a reducing agent or hydrogen in the presence of a metal with a large tendency to convert into hydrogen. A method for treating a decomposition solution of radioactive sulfur-containing organic waste, which is characterized by heating and concentrating the liquid and removing sulfate ions as sulfur dioxide through oxidative decomposition, and a method containing sulfate ions obtained by oxidatively decomposing radioactive sulfur-containing organic waste. The decomposed solution is heated and concentrated in the presence of a reducing agent or a metal that has a greater ionization tendency than hydrogen, and after removing sulfuric acid ions as sulfur dioxide by oxidative decomposition, the pH is adjusted as necessary, water is removed, and the reaction is carried out. This is a method for volume reduction and solidification of a decomposed solution of radioactive sulfur-containing waste, which is characterized by mixing the residue with solidified waste and solidifying it.

The drawings are process diagrams for explaining the present invention.

In the method of the present invention, for example, as shown in Figure J, sulfur-containing organic waste, such as a sulfur-containing ion exchange resin 1, is first oxidized and decomposed by any chemical decomposition method to form an oxidized decomposition liquid 2.

This oxidative decomposition can be carried out using the aforementioned method using hot concentrated sulfuric acid and an oxidizing agent, the method of contacting with hydrogen peroxide in the presence of a metal salt, or the method of using oxygen-containing gas at a temperature of 20.0 to 300°C and a pressure of 20 to 100 atm. This is done by press-fitting.

As the metal salt, one or more selected from ferrous sulfate, ferric sulfate, ferrous nitrate, ferric nitrate, and copper sulfate are used. A suitable concentration of these metal salts is such that the metal content in the reaction solution is 500 to 10,000 ppm.

The concentration of hydrogen peroxide solution is 112O2 in the aqueous solution of the reaction system.
Approximately 1 to 40% in terms of conversion is suitable. Although the reaction proceeds at room temperature, it is desirable to heat the reaction to proceed. Above the reaction temperature, 50°C or higher, especially 90-100'
A range of C is suitable.

A typical example of the sulfur-containing organic waste material that is the subject of the present invention is a mixed ion exchange VA resin containing -C cations, canals, and anions, which is generally used in the treatment of Q'J-related waste liquids at nuclear power plants. For example, styrene and divinylbenzenesulfonic acid are polymerized, and there are powdered or granular synthetic resins with sulfmene groups or (niamino groups) inside them.

In the above oxidative decomposition reaction, carbon components and hydrogen components in the ion exchange resin are oxidized to mainly generate carbon dioxide gas and water vapor, and a transparent liquid product is obtained as an oxidative decomposition liquid. Since this oxidative decomposition reaction is carried out at a lower temperature than in the dry incineration method, the transfer of release capacity to the generated carbon dioxide gas and water vapor is extremely small, and it can be treated using conventional waste waste treatment technology. . The oxidative decomposition liquid 2 contains, for example, sulfate ions generated when oxidatively decomposing a sulfur-containing ion exchange resin having sulfur A> groups, metal ions due to metal salts, sulfate ions, and the like.

This oxidized decomposition liquid 2 is then reductively decomposed, but it is desirable to remove existing metal ions by electrolytic scouring prior to this reduction. In this electrolytic refining method, for example, an electrolytic refining tank in which PL is positive and Cu or Fe is negative is used, and the metal ions present in the oxidized decomposition liquid 2 are made negative by the reaction shown by the following formula. It precipitates out.

Fe""+ 2e-' + r-eFe3" +
3e −−−→ FeCu”+ 2e−−
+G.

Through such a reaction, almost 100% of the metal ions in the oxidized decomposition solution can be deposited on the negative electrode and recovered.

The oxidized decomposition solution 4 in which metal ions have been precipitated in this way is then heated and concentrated while being brought into contact with a reducing agent such as charcoal or sulfur, or a metal such as Cu, which has a lower ionization tendency than ice water. The roots are converted to sulfur dioxide and removed to obtain a reductive decomposition residue 3.

When using a reducing agent such as charcoal or carbon dioxide, the sulfate ions are completely reduced to sulfur dioxide (previously, and when using a metal with 1 fdli such as Cu, 1. 50% of it is decomposed.

That is, in the former case, the sulfuric acid ion becomes sulfur dioxide due to the following reaction, and in the latter case, when the liquid temperature becomes 130"C or higher, the sulfuric acid in the oxidized decomposition solution becomes sulfur dioxide. and copper react as follows, producing copper sulfate in equimolar amounts as sulfur dioxide.

Cu +2H2SO4'-→ CU 804 +SO2T+2H20T, that is, is d3 necessary for the reaction with Cu? :' Il, , 1 mole of copper sulfate is generated from 1 atom of metallic copper, and 1 mole of sulfate ion is removed from the oxidative decomposition liquid as sulfur dioxide. Therefore, even when metallic copper is used, 50% of sulfate ions can be removed.

Regarding the sulfur dioxide generated in this desulfurization reaction, the transfer to radioactive gas is extremely small, similar to the carbon dioxide scum and water vapor that accompany the oxidative decomposition reaction of the resin mentioned above, and it cannot be treated with conventional waste gas treatment technology. It is possible.

In addition, the reduced residue liquid 3 remaining from the desulfurization reaction using metallic copper
The solution can be reused to decompose the radioactive ion exchange resin, so if this reaction solution is used, there is no need to use new copper sulfate for oxidative decomposition, and the sulfate radicals can be almost completely decomposed. Can be removed. Further, if the radioactivity concentration in the reaction solution exceeds the allowable amount, copper is precipitated again if necessary, and then the solution is directly treated as waste solution 4 and treated with C. In this case, after neutralization and drying treatment, the obtained powdered dry residue 5 is mixed with, for example, a polyester resin and subjected to an assimilation treatment to form a solidified body 6. According to this method, the generated The history of assimilates is 1/1 of that of conventional ion exchange resins that are solidified into cement as they are.
'100. It can be said that it is 1/20 of the plastic solidification after drying.

[Embodiments of the invention] Examples of the present invention will be described below.

Example 1 A dry powdered mixed ion exchange resin (trade name: Powdex) and this ion exchanger were placed in a 4-necked flask equipped with a condenser and a stirrer. 'tlIJri5 per 100 copies
000 parts of water was added to -C and thoroughly mixed, then I-(2
2. Hydrogen oxide water and Fe at a temperature of 1 part %. The concentration of (SO4)3 was 0.01 mol/β after the straw was added with a second or higher acid, heated to 100°C, and mixed and stirred at this temperature for 1 hour. Progress of the reaction. As time passes, gas is generated, and the solution initially turns cloudy.
The liquid will eventually turn into a clear liquid. The gas generated here was condensed in a condenser, the condensed liquid was returned to the reaction residue liquid in the reactor, and the gas was directly led to the next gas treatment culm.

Next, the reaction residue liquid was electrolyzed in an electrolytic scouring tank C' with Pt as an anode and Fe as a cathode, and the ``0 minute'' in the liquid was electrolyzed.
It was precipitated. Next, a theoretical amount of charcoal powder was added to the electrolysis residue solution and concentrated by heating. At 130°C, it was observed that sulfur dioxide and carbon dioxide gas were generated from the liquid due to the reaction between sulfate ions and charcoal, and at 180°C, 100% of the sulfate ions were decomposed. After adjusting the pH, this liquid residue was treated with conventional waste liquid treatment 3g3 system τ' and can be disposed of.The liquid after pH adjustment was also neutralized, subjected to spontaneous drying, and solidified into plastic using polyester resin. However, just by oxidative decomposition, the volume could be reduced to about 115 ml compared to the case of neutralization, evaporation drying, and plastic solidification treatment.

Example 2 A powdered mixed ion exchange resin (trade name: Baudex) in a dry state was added to the 4-type flask used in Example 1, and the concentration of 1500 parts of metal steel per 100 parts of this ion exchange resin was about 6000 ppm. Add copper sulfate aqueous solution of
It was heated to a temperature of 80-100°C. Then, while stirring with a stirrer, an aqueous hydrogen peroxide solution having a concentration of 60% was added at a constant flow rate of 3011° C. per 1 g of dry ion exchange resin to oxidize the -C ion exchange resin and decompose it into a gaseous product and a liquid residue. The remainder of the decomposition solution was electrolyzed in an electrolytic refining tank with an anode of 10 t and a cathode of CU, so that almost 100% of the CIJ content in the evening was deposited on the 0 (J electrode). After that, the electrolytic residue solution was precipitated. It was concentrated by heating without contacting with metal steel.It was observed that sulfur dioxide was generated from the liquid due to the decomposition of sulfate ions at about 130℃, and at 150℃ it was 50% of the theoretical m.
It was observed that the sulfur scion had decomposed. This liquid residue (J, l) is treated with a conventional waste liquid treatment system after H adjustment,
1m liquid is possible, and when the liquid material after H adjustment is neutralized, dried with F, and assimilated with PLUSDEC using Polynisder resin, it is oxidized and decomposed. Approximately 1□7 compared to assimilation treatment
We were able to reduce the volume to 2.

In addition, the waste ion exchange resin decomposition treatment similar to the U Fj degree was carried out by using the residual liquid containing copper, which has been obtained by decomposing this rliil acid ion, in combination with an aqueous hydrogen peroxide solution, or in this case also, a metal salt aqueous solution and a hydrogen peroxide solution It was confirmed that the method had the same ability to decompose organic waste as when using A-containing organic waste.

[Effects of the Invention] As is clear from the above explanation, according to the method of the present invention, the oxidative decomposition reaction varicella is reduced by 100 to 150 compared to the conventional method.
'C, which is an easy-to-handle condition, reduces the burden on equipment and equipment materials, and provides high volume reduction performance. In addition, since there is almost no transfer of radioactivity to the generated gas, it can be used as a normal open gas treatment.

Furthermore, since sulfate ions originating from sulfur-containing organic waste are decomposed, the amount of secondary waste is reduced to an extremely small 4f.

[Brief explanation of the drawing]

The drawing is a one-step diagram schematically showing the process of the present invention. 1...Waste ion exchange resin 2...
・・・・・・・・・Oxidation decomposition liquid 3・・・・・・・・・・・・
・・Reduced residual liquid 4・・・・・・・・・・Waste liquid 5・・・・・・・・・・Dried residual liquid 6・・・・・・・・・・・・Solidification Patent Attorney Suyama Sa - Procedural Amendment Book 1970*7r:q 4El Commissioner of the Patent Office 1, Indication of Case Patent Application 1970-59704%J Taku 2,
Name of the invention Method for processing radioactive sulfur-containing organic waste decomposition liquid and method for volume reduction and solidification 3 Relationship with the case of the person making the amendment ・Patent applicant Kanagawa, Japan Atomic Energy Corporation, 13-12 Mita 3-chome, Minato-ku, Tokyo 72 Horiyo-cho, Saiwai-ku, Kenyousaki-shi (307) Toshiba Corporation 4, Representative Address: 2-1 Kanda Ta-cho, Chiyoda-ku, Tokyo 101 Full text of Memorandum A 7, contents of amendment attached to the amended statement Description 1. Title of the invention: Method for treating radioactive sulfur-containing organic waste decomposed liquid and volume reduction solidification method 2. Claims (1) Containing sulfate ions obtained by oxidative decomposition of radioactive sulfur-containing organic waste. A decomposition solution for radioactive sulfur-containing organic waste, characterized in that the decomposition solution is heated and concentrated in the presence of a reducing agent or a metal with a greater ionization tendency than hydrogen, and sulfate ions are converted into sulfur dioxide by oxidative decomposition and removed at °C. processing method. (2) The decomposition liquid is a decomposition liquid of radioactive sulfur-containing organic waste as claimed in claim 1, which is obtained by oxidatively decomposing the radioactive sulfur-containing organic waste by contacting it with hydrogen peroxide in an aqueous metal salt solution. Processing method. (3) The decomposition liquid is a radioactive sulfur-containing organic compound as claimed in claim 1, which is obtained by injecting a gas containing oxygen under heat and pressure into a liquid containing radioactive sulfur-containing waste and oxidizing it. Processing method for waste decomposition liquid. (4) The decomposition liquid has a temperature of 200 to 300'C and a pressure of 20
4. The method for treating a radioactive sulfur-containing organic waste decomposition solution as claimed in claim 3, which is obtained by oxidizing the radioactive sulfur-containing organic waste by injecting oxygen-containing gas under pressure at ~100 atmospheres. (5,) The metal salt is one or two selected from ferrous sulfate, ferric sulfate, ferrous nitrate, ferric nitrate, and copper sulfate.
A method for treating a radioactive sulfur-containing organic waste decomposition solution according to claim 2, which comprises at least one species. (6) The concentration of metal salt in an aqueous solution is the metal ion (calculated)
500-1100001) The method for treating a radioactive sulfur-containing organic waste decomposition solution according to claim 1, wherein the decomposed solution is Fl. (7) The method for treating a radioactive sulfur-containing organic waste decomposition solution according to claim 2, wherein the concentration of hydrogen peroxide in the aqueous solution is 1 to 40% in terms of H202. (8) The method for treating a radioactive sulfur-containing organic waste decomposition solution according to claim 2, wherein the oxidative decomposition is carried out at a temperature of 80 to 100°C. (9) A decomposition solution containing sulfate ions obtained by oxidative decomposition of radioactive sulfur-containing organic waste is heated and concentrated in the presence of a reducing agent or a metal that has a greater tendency to ionize than hydrogen, and the sulfate ions are oxidatively or reductively decomposed. Decomposition of radioactive sulfur-containing organic waste, which is characterized by removing sulfur dioxide as sulfur dioxide, adjusting the pH as necessary, removing volatile components such as water or Δ, and solidifying the reaction residue by mixing it with a solidifying material. Volume reduction and solidification method of liquid. 2 (12) The decomposition liquid for radioactive sulfur-containing organic waste according to claim 9, wherein the decomposition liquid is a liquid obtained by oxidizing and decomposing the radioactive sulfur-containing organic waste in an aqueous metal salt solution while avoiding contact with hydrogen peroxide. volume reduction solidification method. (13) The metal salt is one or two selected from ferrous sulfate, ferric sulfate, ferrous nitrate, ferric nitrate, and copper sulfate.
11. The method for volume reduction and solidification of a radioactive sulfur-containing organic waste decomposition solution according to claim 10, which comprises at least one species. (14) The method for volume reduction and solidification of a radioactive sulfur-containing organic waste decomposition solution according to claim 10, wherein the concentration of the metal salt in the aqueous solution is 500 to 10,000 pHIII in terms of metal ions. (15) The method for volume reduction and solidification of a radioactive sulfur-containing organic waste decomposition solution according to claim 10, wherein the concentration of hydrogen peroxide in the aqueous solution is 1 to 40% in terms of H'202. 3. Detailed Description of the Invention [Technical Field of the Invention] The present invention relates to a method for treating a decomposed liquid obtained by oxidizing and decomposing radioactive sulfur-containing waste generated in facilities handling radioactive materials such as nuclear power generation facilities, and a method for treating this decomposition solution. This invention relates to a method for volume reduction and solidification of radioactive sulfur-containing organic waste for volume reduction and solidification of liquid. [Technical background of the invention and its problems] A variety of radioactive solid wastes are generated in facilities that handle radioactive materials such as nuclear power plants, but at present, the final disposal method for most of them has not yet been established and is in a state of flux. Therefore,
Used ion exchange resins and filter sludge, which are the main components of solid waste, are mainly stored in tanks, etc., and reducing the amount of radioactive waste generated is urgent and important in storage management. This is considered an issue. Among such solid wastes, radioactive organic wastes such as used radioactive ion exchange resins are generated in large quantities, so reducing the volume of this waste greatly contributes to reducing the amount of wastes generated. By the way, radioactive organic waste is a polymeric compound, and it is possible to decompose it chemically to reduce its volume. Methods of volume reduction, such as methods, are being considered. Among these, the dry incineration method is a method in which the waste is incinerated as it is in an incinerator, and many methods are being developed laterally. However, when incinerating radioactive organic waste in an incinerator, a heat capacity controller is required, so pretreatment such as drying and waste supply methods must be devised, making operations and equipment complicated. There is a drawback. In addition, since the incinerator itself does not have a function to suppress the scattering of incinerated ash, IJ9. The scattering of rigid incineration ash is very large (D
I-: Decontamination coefficient is approximately 1). And as incineration gas, S
Harmful gases such as OX and NOx are generated as radioactive gases, so post-processing called waste gas treatment is necessary, including radioactivity countermeasures, and these residues are highly corrosive, making it difficult to select equipment materials. There are other problems. Furthermore, in this method, since the radioactive organic waste is processed in a high-temperature environment, there is a problem unique to the handling of radioactivity, that is, so-called nuclide migration, in which radioactive components migrate into the generated incineration gas. In the wet incineration method, 2
This is a method of incinerating radioactive organic waste by pumping oxygen or air under high temperature and high pressure conditions of 0 to 100 atmospheres and 200 to 300 degrees Celsius, and in addition to the severe incineration conditions, the volume reduction rate is also the same as mentioned above. The disadvantage is that it is several steps inferior to dry incineration. Furthermore, the pyrolysis method is a method of thermally decomposing radioactive organic waste by cutting off the supply of oxygen, and generates 9XM compared to the dry incineration method. It has the advantage that the amount of However, this method requires an extra step of burning the cracked gas, and, like the dry incineration method, there is the problem of radionuclide migration. On the other hand, the chemical decomposition method oxidizes and decomposes the resin through a chemical reaction with a drug, and the following methods are known. ■ A method of carbonizing radioactive organic matter with hot concentrated sulfuric acid (130-300°C) and then oxidizing and decomposing it with nitric acid or hydrogen peroxide. ■ Iron ion or lc is a method in which organic waste is oxidized and decomposed by contacting it with a hydrogen peroxide solution in a solution containing chromate ions or dichromate ions. However, in these methods, for example, the method (2) handles strong acids and oxidizing agents at high temperatures, so the selection of equipment materials is very strict. Sulfate is generated as a secondary waste due to the neutralization of sulfate ions derived from sulfur-containing organic waste such as mixed ion exchange resin, so the concentration of waste liquid is high and the volume is reduced when solidified. The problem is that the effect is not so strong. [Object of the invention] The present invention has been made in response to such conventional circumstances,
A method for treating radioactive sulfur-containing organic waste decomposition liquid, which reduces the concentration of waste liquid by removing even inorganic ions and achieves a high volume reduction rate when solidified under mild conditions that are easy to implement. and to provide a volume reduction and solidification method. [Summary of the invention] That is, the present invention heats and concentrates a decomposition solution containing sulfate ions obtained by oxidative decomposition of radioactive sulfur-containing organic waste in the presence of a reducing agent or a metal that has a greater tendency to ionize than hydrogen. , a method for treating a decomposition solution of radioactive sulfur-containing organic waste characterized by removing sulfate ions as sulfur dioxide through oxidative decomposition, and a decomposition solution containing sulfate ions obtained by oxidatively decomposing radioactive sulfur-containing organic waste. , heat and concentrate in the presence of a reducing agent or a metal with a greater ionization tendency than hydrogen, remove sulfuric acid ions as sulfur dioxide by oxidative decomposition, adjust the pH as necessary, remove moisture or further volatile components, and react. This is a method for volume reduction and solidification of decomposed liquid of radioactive sulfur-containing organic waste, which is characterized by mixing the residue with a solidifying material and solidifying it. The drawings are process diagrams for explaining the present invention. In the method of the present invention, for example, as shown in the figure, sulfur-containing organic waste, for example, sulfur-containing ion exchange resin 1
is oxidized and decomposed by any chemical decomposition method to produce oxidized decomposition liquid 2.
It is said that This oxidative decomposition can be carried out by contacting with hydrogen peroxide in the presence of the metal salts mentioned above, or by introducing oxygen in an aqueous solution containing waste or an aqueous copper sulfate solution containing waste at a temperature of 200 to 300°C and a pressure of 20 to 100 atm. This is done by injecting the gas containing the gas under pressure. As the metal salt, one or more selected from ferrous sulfate, ferric sulfate, ferrous nitrate, ferric nitrate, and copper sulfate are used. The concentration of these metal salts is 500 to 110000111 p as metal content in the reaction solution.
The extent to which it exists is appropriate. The concentration of the hydrogen peroxide solution in the aqueous solution of the reaction system is preferably about 1 to 40% in terms of H2O2. Although the reaction proceeds at room temperature, it is desirable to heat the IC to allow the reaction to proceed. The reaction temperature is preferably 50°C or higher, particularly in the range of 90 to 100°C. Typical examples of sulfur-containing organic wastes that are the subject of the present invention include cation exchange resins or mixed ion exchange resins containing cations and anions, such as styrene and divinylbenzenesulfonic acid, which are commonly used for radioactive waste liquid treatment at nuclear power plants. There are powdered or granular products that have sulfone groups or amino groups inside the synthetic resin that has not been polymerized. In the above oxidative decomposition reaction, carbon components and hydrogen components in the ion exchange resin are oxidized to mainly generate carbon dioxide gas and water vapor, and a transparent liquid product is obtained as an oxidative decomposition liquid. Since this oxidative decomposition reaction is carried out at a lower temperature than in the dry incineration method, the transfer of radioactivity to the generated carbon dioxide gas and water vapor is extremely small, and it can be treated using conventional waste gas treatment techniques. Note that this oxidative decomposition liquid 2 contains, for example, sulfate ions generated when oxidatively decomposing a sulfur-containing ion exchange resin having a sulfone group, etc.
Contains metal ions and sulfate ions due to metal salts. This oxidized decomposition liquid 2 is then reductively decomposed, but it is desirable to remove existing metal ions by electrolytic refining prior to this reduction. In this electrolytic refining method, -C is
For example, an electrolytic refining tank in which Pt is positive and Cu or Fe is negative is used, and metal ions present in the oxidized decomposition liquid 2 are precipitated on the negative surface by a reaction represented by the following formula. Fe2++ 20−−1 → Fe Fe” + 3e−−−→ Fe
CLI 2” + 2e -----> Cu Due to this reaction, the metal ions in the oxidized decomposition liquid are reduced to approximately 10
It can be deposited on a 0% negative electrode and recovered. The oxidized decomposition solution 4 in which metal ions have been precipitated in this way is then heated and concentrated while being brought into contact with a reducing agent such as charcoal or sulfur, or a metal such as CLI, which has a lower ionization tendency than hydrogen. The roots are reduced to sulfur dioxide and removed to obtain reduced decomposition residue 3. When using a reducing agent such as charcoal or sulfur,
Sulfate ions become sulfur dioxide almost completely, and C
When a metal such as u is used, theoretically 50% of it is decomposed. In other words, in the former case, sulfate ions become sulfur dioxide through the following reaction, 2H2SO4+C-1→2S○2↑+CO2↑+2H20↑ In the latter case, when the liquid temperature becomes 130°C or higher, sulfuric acid in the oxidized decomposition liquid and copper react as follows, producing copper sulfate in equimolar amounts as sulfur dioxide. Cu → -21-12804-1 → Cu SO4+SO2↑+2H20↑ In other words, in J5 reaction with CU, 1 mole of copper sulfate is produced from 1 mole of metallic copper, and at the same time, 1 mole of ll7ii acid ion is converted into sulfur dioxide and decomposed by -C oxidation. It will be removed from liquid 2. Therefore, even when using metallic copper, 50%
can remove sulfate ions. The sulfur dioxide generated in this desulfurization reaction, like the carbon dioxide gas and water vapor that accompany the oxidative decomposition reaction of the resin mentioned above, transfers to radioactive and active gases is extremely small and cannot be treated with conventional waste gas treatment technology. It is possible. Note that the three reduced residual solutions remaining from the desulfurization reaction using metals can be reused to decompose the radioactive ion exchange resin. There is no need to use salt, and the sulfate radicals can be almost completely decomposed and removed. In addition, if the radioactivity concentration in the reaction solution exceeds the allowable amount, the metal may be precipitated again if necessary, or the solution may be treated as waste solution 4 and treated with "C".In this case, neutralization and After drying, the obtained powdered dry residue 5 is mixed with, for example, a polyester resin and solidified to form a solidified body 6. According to this method, the amount of assimilated product generated is smaller than that of the conventional method. 1 when solidifying the ion exchange resin into cement as it is
/100. The amount can be reduced to 1/20 of the case where the plastic is solidified after drying. [Embodiments of the Invention] Examples of the present invention will be described below. Example 1 A dry mixed powdered ion exchange resin (trade name: Powdex) and 5000 parts of water per 100 parts of this ion exchange resin were added to a four-necked flask equipped with a condenser and a stirrer, and thoroughly mixed. Next, a skewer of hydrogen peroxide and Fe 2 (S
Ferric sulfate was added in an amount such that the concentration as O4)3 was 0.01 mol/β, the mixture was heated to 100° C., and mixing and stirring was continued at this temperature for 1 hour. As the reaction progresses, gas is generated,
The solution initially becomes cloudy, but eventually becomes a clear liquid. The gas generated here was condensed in a condenser, the condensed liquid was returned to the reaction residue liquid in the reactor, and the gas was directly led to the next gas treatment step. Next, the reaction residue solution was electrolyzed in an electrolytic refining tank with Pt as an anode and Fe as a cathode, so that almost 100% of the Fe content in the solution was deposited on the electrodes. Next, a theoretical amount of charcoal powder was added to the electrolysis residual solution and concentrated by heating. At 130°C, it was observed that sulfur dioxide and carbon dioxide gas were generated in the liquid due to the reaction between sulfate ions and charcoal, and at 180°C, 100% decomposition of the sulfate ions was observed. After adjusting the pH, this liquid residue can be treated with a conventional waste liquid treatment system and disposed of.Also, when the liquid after pH adjustment is neutralized, evaporated and dried, and solidified into plastic using polyester resin, it is oxidized and decomposed. It was possible to reduce the volume to about 115 ml compared to the case where the plastic was solidified by neutralization, evaporation drying, and plastic solidification treatment. Example 2 Into the four-necked flask used in Example 1, a powdered mixed ion exchange resin (trade name: Powdex) in a dry state and 100 parts of this ion exchange resin and 1500 parts per 100 parts of this ion exchange resin had a concentration of about 60001 as metallic copper. ) pm copper sulfate aqueous solution was added and heated to a temperature of 80 to 100°C. Then, while stirring with a stirrer, an aqueous hydrogen peroxide solution having a concentration of 60% was added at a constant flow rate of 30 mβ per gram of dry ion exchange resin to oxidize the ion exchange resin and decompose it into a gaseous product and a liquid residue. The remainder of the decomposition solution was used as a Pt anode. Electrolysis was performed in an electrorefining tank with Cu as the cathode, and almost 100% of the Cu content in the liquid was deposited on the Cu electrode. Thereafter, the electrolytic residue solution was heated and concentrated while being brought into contact with the precipitated metal copper. At about 130°C, sulfur dioxide was observed to be generated from the liquid due to the decomposition of sulfate ions, and at 150°C, it was observed that 50% of the theoretical amount of sulfate ions had been decomposed. This liquid residue can be treated with a conventional waste liquid treatment system after l) H adjustment and disposed of, and l) The liquid after H adjustment, neutralized and evaporated dry, can be used to make polyester resin - C plastic. When solidified, the volume could be reduced to about 1/2 compared to when the plastic was assimilated through neutralization, evaporation drying, and plastic assimilation just by oxidative decomposition. In addition, the copper sulfate-containing residual solution obtained by decomposing this sulfate ion was used in combination with an aqueous hydrogen peroxide solution to decompose waste ion exchange resin in the same way as at pJ, but in this case, an aqueous metal salt solution and aqueous hydrogen peroxide were also used. It was confirmed that the method had the same ability to decompose sulfur-containing organic waste. [Effect of the invention] As is clear from the above explanation, according to the method of the present invention, the oxidative decomposition reaction temperature is 100 to 150% lower than that of the conventional method.
Since the conditions are easy to handle at ℃, there is less burden on equipment and equipment materials, and high volume reduction properties can be obtained. Furthermore, since there is almost no transfer of radioactivity to the generated gas, it can be dealt with by normal waste gas treatment. Furthermore, since sulfate ions derived from sulfur-containing organic waste are decomposed, the amount of secondary waste is extremely reduced. 4. Brief description of the drawings The drawings are process diagrams schematically showing the culm of the present invention. 1...Waste ion exchange resin 2...
・・・・・・・・・Oxidation decomposition liquid 3・・・・・・・・・・・・
・・Reduced residual liquid 4・・・・・・・・・・Waste liquid 5・・・・・・・・・・Dried residue 6・・・・・・・・・・・・Solidized material

Claims (1)

[Scope of Claims] (1) A decomposition solution containing sulfate ions obtained by oxidative decomposition of radioactive sulfur-containing organic waste is heated and concentrated in the presence of a reducing agent or a metal that has a higher ionization tendency than hydrogen, and sulfate ions are 1. A method for treating a decomposition solution of radioactive sulfur-containing industrial waste, the method comprising removing sulfur dioxide as sulfur dioxide through oxidative decomposition. (2) The decomposition solution is obtained by oxidatively decomposing the radioactive sulfur-containing organic waste by contacting it with hydrogen peroxide in an aqueous metal salt solution and decomposing the radioactive sulfur-containing organic waste according to claim 1. How to treat liquid. (3) The decomposition liquid is oxidized by injecting oxygen-containing gas under heat and pressure into the liquid containing radioactive sulfur-containing vehicles.
C. A method for treating a decomposed liquid of free-flowing sulfur-containing organic waste according to claim 1. (4) The decomposition liquid has a temperature of 200 to 300°C and a pressure of 20 to 1
4. A method for treating a radioactive sulfur-containing organic waste decomposition solution as claimed in claim 3, which is obtained by oxidizing radioactive sulfur-containing organic waste by injecting oxygen-containing scum under pressure of 000 atmospheres. (5) The metal salt is one or two selected from ferrous sulfate, ferric sulfate, ferrous nitrate, ferric nitrate a5, and copper sulfate.
A method for treating a radioactive sulfur-containing waste decomposition solution as claimed in claim 2, which comprises at least one radioactive sulfur-containing waste decomposition solution. (6) The temperature of the total ion in the metal salt aqueous solution is 500~
110,000 pp. The method for treating the radiation-containing sulfur autologous waste τ substance M solution as set forth in item 2 of the specification 5'I. (7) The method for treating a decomposed liquid of sulfur-containing organic waste as claimed in claim 2, wherein the degree of opening (of hydrogen peroxide) is 1.4.0% in terms of HL 202. (The method for treating a radioactive sulfur-containing organic waste decomposition solution according to claim 2, wherein the oxidative decomposition is carried out at a temperature of 80 to 100°C. (9) Liquification of radioactive sulfur-containing 1m IQ The decomposed solution containing sulfate ions is heated and concentrated in the presence of a reducing agent or a metal that has a greater ionization tendency than hydrogen, and the sulfate ions are converted into sulfur dioxide by oxidative decomposition, and after C is removed, if necessary -U A method for volume reduction and solidification of a decomposed liquid of radioactive sulfur-containing organic waste, which comprises adjusting the pH, removing water, and solidifying the reaction residue by mixing it with a solidifying material. (10) The decomposed liquid contains radioactive sulfur. A method for volume reduction and solidification of a radioactive sulfur-containing waste decomposition liquid according to claim 1, which is a liquid obtained by oxidative decomposition of sulfur organic waste confectionery by contacting it with hydrogen peroxide in an aqueous metal salt solution. 11) The metal salt is one or two selected from ferrous sulfate, ferric sulfate, ferrous nitrate, ferric nitrate, and copper sulfate.
9. A method for volume reduction and solidification of a decomposed solution of radioactive and sulfur organic waste as set forth in claim 8. <12) The concentration of metal ions in the metal salt aqueous solution is 500
110,000 pl), the volume reduction and solidification method of a decomposed solution of sulfur-containing waste as claimed in claim 9. (13) The m degree of hydrogen peroxide is 1 to 1 in terms of l-1202.
11. The method for volume reduction and solidification of radioactive sulfur-containing waste decomposition liquid according to claim 10, wherein the decomposition liquid is 40%.