A method for treating organic waste liquid containing radioactive isotope carbon-14

Abstract

The present invention provides a method for treating organic waste liquid containing radioactive isotope carbon‑14, comprising blowing inert gas into the organic waste liquid containing carbon‑14 under low temperature conditions and capturing carbon‑14 markers as low-temperature captures in a low-temperature environment, converting the carbon‑14 markers into a solid substance that is easy to handle by means of adsorbent adsorption or salt formation, subjecting the low-temperature captures obtained by atmospheric distillation to supercritical water oxidation system treatment and then alkaline solution treatment to obtain a solid substance that is easy to handle, and then subjecting the residual waste liquid to alkalization and acidification treatment and then distillation to obtain a distillation solid residue. The method is particularly suitable for the overall treatment of organic waste liquid containing carbon‑14 generated during the synthesis and tracing research of radioactive isotope carbon‑14 markers of chemicals such as agricultural medicines, and provides a systematic solution to the problems of reduction, harmlessness and resource utilization of organic waste liquid containing carbon‑14.

Description

Technical Field

[0001] The present invention relates to the field of radioactive waste treatment, and more particularly to a method for treating organic waste liquid containing the radioactive isotope carbon-14, and more particularly to a method for treating organic waste liquid containing carbon-14 generated during the application of the radioactive isotope carbon-14 in the field of civilian non-power nuclear technology. Background Art

[0002] Carbon-14 is one of the long-half-life radioactive nuclides commonly used in the current field of civilian non-power nuclear technology. At present, the radioactive isotope carbon-14 is mainly used in the labeling synthesis and tracing research of chemicals such as medicines, pesticides, environmental pollutants, and veterinary drugs. In the process of carbon-14 labeling synthesis and tracing application of pesticides and other chemicals, it is inevitable to produce organic waste liquid containing radioactive carbon-14. These organic waste liquids containing radioactive carbon-14 have the characteristics of large volume, high activity concentration, complex chemical state of the nuclide carbon-14, great difficulty in post-solidification, high safety risk, and high disposal cost.

[0003] At present, the domestic disposal of radioactive carbon-14 wastes usually uses cement to make carbon-14 wastes with extremely low levels of radioactivity concentration into cement solids with a certain mechanical strength, and then transports them to the disposal site of the National Radioactive Waste Repository and buries them deep underground for long-term (more than a thousand years) storage and treatment. However, compared with carbon-14 wastewater, the chemical composition of non-radioactive components (accounting for more than 95% of the mass in this type of waste liquid) in carbon-14 organic waste liquids generated during the synthesis and tracing research of chemical carbon-14 labeling is more complex, containing a variety of organic solvents commonly used in labeling synthesis and tracing experiments (including but not limited to dichloromethane, tetrahydrofuran, acetone, 2-methyltetrahydrofuran, acetonitrile, methanol, ethanol, dichloroethane, carbon tetrachloride, benzene, toluene, nitrobenzene, N , N -dimethylformamide, dimethyl sulfoxide, ethyl acetate, n-hexane, petroleum ether, triethylamine, pyridine, trifluoroacetic acid, methyl tert-butyl ether), and some of the radioactive carbon-14 labeled substances in this type of carbon-14 organic waste liquid are small molecular compounds (relative molecular mass is usually less than 100). At room temperature, these compounds are mostly gases (extremely volatile) or low-boiling liquids (volatile), which are easy to diffuse and overflow, seriously endangering the safety of operators and the environment. This has been a difficult problem that has plagued the pretreatment of carbon-14 organic waste liquid for many years.

[0004] Different from the treatment of carbon-14 wastewater, the organic phase in carbon-14 organic waste liquid has poor compatibility with the inorganic phase of cement. Directly solidifying carbon-14 organic waste liquid with cement will not only destroy the hydration reaction between cement and stone, weaken the bonding force between cement and stone, and reduce the maximum carrying capacity of cement solid body for radioactive waste, but also seriously affect the hardening ability of cement solid body, resulting in reduced strength.

[0005] Therefore, there are many difficulties in the treatment of carbon-14 organic waste liquid with medium or low level radioactive activity concentration generated during the carbon-14 labeling synthesis and tracing process of agricultural and pharmaceutical chemicals: how to reduce the volume and amount of radioactive waste liquid in carbon-14 organic waste liquid, safely treat the highly volatile / volatile radioactive carbon-14 labeled small molecule compounds therein, recover the carbon-14 labeled substances in the waste liquid as much as possible, and convert the waste liquid containing carbon-14 markers that are difficult to recover into a solid state, reduce the radioactive activity concentration of such waste liquid to the exemption level (clean clearance level), and eliminate the technical bottleneck in the cement solidification disposal of such radioactive waste before the transportation in the later stage. These are all problems that need to be urgently solved in the treatment of carbon-14 organic waste liquid generated during the carbon-14 labeling synthesis and tracing process. Summary of the invention

[0006] The purpose of the present invention is to provide a method for treating organic waste liquid containing radioactive isotope carbon-14, which is particularly suitable for the overall treatment of organic waste liquid containing carbon-14 generated during the radioactive isotope carbon-14 labeling synthesis and tracing research of chemicals such as agricultural medicines, and provides a systematic solution to the problems of reduction, harmlessness and resource utilization of organic waste liquid containing carbon-14.

[0007] To achieve the above objectives, the present invention provides a method for treating organic waste liquid containing radioactive isotope carbon-14, which is suitable for treating organic waste liquid containing carbon-14 generated during the radioactive isotope carbon-14 labeling synthesis and tracing research of chemicals such as agricultural medicines, and comprises the following steps:

[0008] S1: In the temperature range of -70 ℃ to -50 ℃, an inert gas is blown into the carbon-14 organic waste liquid to be treated, and the carbon-14 marker in the escaped gas of the carbon-14 organic waste liquid is captured as the first low-temperature capture material at a temperature below -130 ℃, until there is no obvious radioactivity in the escaped gas to obtain the first carbon-14 organic waste liquid I, and the first low-temperature capture material is pumped into the adsorbent to adsorb the carbon-14 marker and the adsorbent is collected as the first adsorbent;

[0009] S2: In the temperature range of -10°C to 10°C, an inert gas is blown into the first carbon-14 organic waste liquid I, and the carbon-14 marker in the escaped gas of the carbon-14 organic waste liquid is captured as the second low-temperature capture material in the temperature range of -130°C to -100°C, until there is no obvious radioactivity in the escaped gas to obtain the second carbon-14 organic waste liquid II, and the second low-temperature capture material is pumped into a low-temperature lower alcohol at room temperature to obtain an alcohol solution, and a carboxylate is added to the alcohol solution, and then the solution is sealed and heated for a period of time, and the first solid is obtained after it is cooled to room temperature;

[0010] S3: in the temperature range of 40 ℃ to 50 ℃, the second carbon-14 organic waste liquid II is subjected to atmospheric distillation, and the distillate is captured at -30 ℃ to -20 ℃ as the third low-temperature captured material, until no distillate is evaporated to obtain the third carbon-14 organic waste liquid III, the third low-temperature captured material is treated by a supercritical water oxidation system to become carbon-14 carbon dioxide, and the carbon-14 carbon dioxide is absorbed by an alkali solution and then decompressed and desolventized to obtain the second solid;

[0011] S4: adding alkali solution to the third carbon-14 organic waste liquid III and distilling it to obtain a first distillation solid residue and a first distillate;

[0012] S5: introducing an acidic gas into the first distillate and then distilling it to obtain a second distillation solid residue and a second distillate;

[0013] S6: Add the adsorbent to the second distillate, stir and let stand until adsorption equilibrium is reached, and then separate the solid-liquid phases to obtain the second adsorbent and residual waste liquid.

[0014] It should be noted that this scheme is particularly suitable for treating carbon-14 organic waste liquid generated during the synthesis and tracing research of radioactive isotope carbon-14 labeling of chemicals such as agricultural medicines. The non-radioactive organic solvent contained in this type of carbon-14 organic waste liquid accounts for more than 95% of the waste liquid by mass. Considering that organic solvents and cement are immiscible, if this type of carbon-14 organic waste liquid with an organic solvent accounting for more than 95% is directly solidified with cement, it will inevitably affect the solidification reaction and strength of the cement, and reduce the maximum carrying capacity of the cement solidified body for radioactive waste; in addition, the composition of carbon-14 organic waste liquid is complex and the properties of each component vary greatly, and the radioactivity concentration of each carbon-14 marker varies greatly. Therefore, this scheme aims to design an effective and feasible scheme to separate the organic solvent and the carbon-14 marker, so as to facilitate the subsequent cement solidification treatment of the carbon-14 marker.

[0015] In step S1:

[0016] The inert gas is selected from argon and nitrogen. The purpose of blowing the inert gas into the carbon-14 organic waste liquid to be treated is to evaporate the highly volatile gaseous carbon-14 marker (such as [ 14 C] Carbon dioxide, 14 C] formaldehyde, etc.) are blown out.

[0017] In a low-temperature environment below -130°C, cold traps and other equipment are used to capture the carbon-14 markers in the escaping gas. These captured substances are the first low-temperature capture substances. The purpose is to allow the blown-out gaseous carbon-14 markers to be firmly adsorbed by the solid adsorbent to prevent the carbon-14 markers from volatilizing into the air and causing radioactive contamination. It is also necessary to detect until the gas brought out by the inert gas has no obvious radioactivity.

[0018] The first low-temperature capture material is pumped into an adsorption device equipped with an adsorbent, the adsorbent being selected from one or a combination of two or more of highly active activated carbon, molecular sieve, and alumina, and the first adsorbent adsorbing the carbon-14 marker is obtained, and the first adsorbent is temporarily stored. The first adsorbent adsorbing the carbon-14 marker is solid and does not contain an organic solvent, so it can be directly solidified with cement later.

[0019] Step S1 of this scheme is to treat the highly volatile gaseous carbon-14 marker in the carbon-14 organic waste liquid to be treated: this part of the highly volatile radioactive material is separated from the main body of the carbon-14 organic waste liquid to be treated by low-temperature blowing and capturing, so as to prevent it from diffusing and overflowing during the subsequent treatment process, endangering the safety of operators and the environment, and then adsorbing it with an adsorbent, thereby achieving the preliminary fixation and collection of this part of the radioactive material, preparing for further temporary storage and treatment, and also reducing the total amount of radioactive material in the carbon-14 organic waste liquid to be treated.

[0020] In step S2:

[0021] The inert gas is selected from argon and nitrogen. The purpose of blowing the inert gas into the first carbon-14 organic waste liquid I at a temperature range of -10°C to 10°C is to convert the volatile carbon-14 marker (such as [2- 14 C] acetone, [ 14 C] methanol, 14 C]formic acid, [U- 14 C6] benzene, etc.) to further reduce the amount of carbon-14 markers in radioactive organic waste liquid.

[0022] In a low-temperature environment of -130℃~-100℃, cold traps and other equipment are used to capture the carbon-14 markers in the escaping gas. These captured substances are the second low-temperature capture substances. Their purpose is to change the blown carbon-14 markers from liquid to solid, avoiding the low-boiling point carbon-14 markers from volatilizing into the air and causing radioactive contamination. And it is necessary to detect until the gas brought out by the inert gas has no obvious radioactivity.

[0023] The second low-temperature capture material is pumped into a lower alcohol at -20°C to 10°C for absorption at room temperature to obtain an alcohol solution, wherein the lower alcohol is an alcohol containing 1 to 4 carbon atoms, in order to use the lower alcohol to absorb the low-boiling point liquid carbon-14 marker.

[0024] Add carboxylate to the alcohol solution, seal and heat for a period of time, and obtain the first solid after cooling to room temperature, wherein the carboxylate is selected from calcium salt or barium salt of carboxylic acid containing 1 to 4 carbon atoms, sodium salt or potassium salt of carboxylic acid containing 8 to 20 carbon atoms, the heating temperature is 40 ℃ to 80 ℃, and the heating time is 30 min to 3 h. The purpose is to convert the low-boiling point carbon-14 marker from a liquid state into a solid state similar to solid alcohol. The solid contains carbon-14 markers, so it can be directly solidified with cement later.

[0025] Step S2 of this scheme is to treat the volatile liquid carbon-14 marker in the first carbon-14 organic waste liquid I: this part of the low-boiling point liquid carbon-14 marker is separated from the main body of the first carbon-14 organic waste liquid I by low-temperature aeration and capture, and then the captured substance is absorbed by low-level alcohol, and then the carbon-14 substance is converted into a first solid substance by reaction with a carboxylate, thereby realizing the embedding and sealing treatment of this part of the radioactive substance, which is convenient for subsequent collection and temporary storage.

[0026] In step S3:

[0027] The second carbon-14 organic waste liquid II is heated to 40 ℃ ~ 50 ℃ and distilled at normal pressure, and the evaporated material is captured at -30 ℃ ~ -20 ℃ using equipment such as a cold trap. These captured materials are the third low-temperature captured materials, and their purpose is to treat the residual volatile carbon-14 markers in the second carbon-14 organic waste liquid II, evaporate and capture the carbon-14 markers with lower boiling points in the waste liquid, and further separate the radioactive substances.

[0028] The third low-temperature capture material is treated with a supercritical water oxidation system to form carbon-14 carbon dioxide, and the carbon-14 carbon dioxide is absorbed by an alkali solution and then decompressed to obtain a second solid, wherein the alkali can be selected from barium hydroxide, calcium hydroxide, sodium hydroxide, and potassium hydroxide. Since the distillate of atmospheric distillation contains a large amount of organic solvent and a certain amount of volatile carbon-14 marker, and the two are difficult to separate, this scheme uses a supercritical water oxidation system to oxidize the carbon-14 in the third low-temperature capture material to carbon-14 labeled carbon dioxide, and then uses an alkali solution to absorb the carbon-14 labeled carbon dioxide to obtain a first solid that does not contain an organic solvent and is solid, and then the first solid is directly solidified with cement.

[0029] Step S3 of this scheme is to further process the residual carbon-14 markers in the second carbon-14 organic waste liquid II: the carbon-14 markers are separated from the main body of the second carbon-14 organic waste liquid II by atmospheric distillation technology, and then the volatile carbon-14 marker small molecule compounds (relative molecular mass is usually less than 100) are converted into inorganic salts using a supercritical water oxidation system, thereby reducing the safety risks of their volatilization, diffusion and overflow to the subsequent cement curing operation and the environment.

[0030] In step S4:

[0031] The alkali for preparing the alkali solution can be selected from one or any combination of sodium bicarbonate, sodium carbonate, potassium bicarbonate, potassium carbonate, calcium bicarbonate, calcium carbonate, sodium acetate, calcium acetate, sodium hydroxide, and slaked lime. Preferably, the alkali is selected from one or any combination of potassium bicarbonate, sodium carbonate, potassium bicarbonate, and potassium bicarbonate. Correspondingly, after adding the alkali solution to the third carbon-14 organic waste liquid III, it is fully stirred and distilled to dryness to obtain a first distillation solid residue and a first distillate.

[0032] The purpose of adding alkali solution in this scheme is to convert the acidic carbon-14 marker into salt to ensure that the acidic carbon-14 marker will not evaporate during the distillation process but remain in the first distillation solid residue.

[0033] In step S5:

[0034] The acidic gas is HCl, and the acidic gas is introduced into the first distillate and then distilled to dryness to obtain a second distillation solid residue and a second distillate. Similarly, the acidic gas is added in this step to allow the alkaline carbon-14 marker (such as aniline) to react and convert into a salt, so as to ensure that the carbon-14 marker is separated from the organic solvent and will not be evaporated.

[0035] In step S6:

[0036] The adsorbent is selected to be one of activated carbon, silica gel, alumina or a mixture of any of several adsorbents. The adsorbent is added to the second distillate and stirred thoroughly and allowed to stand at room temperature. Then, additional adsorbent is added and stirred thoroughly and allowed to stand until the adsorption equilibrium is reached and the radioactivity concentration of carbon-14 in the liquid phase of the second distillate is less than the exemption level. The solid-liquid phases are separated to obtain the second adsorbent and residual waste liquid and temporarily store them.

[0037] In step S6, an adsorbent is used to adsorb the residual trace carbon-14 marker in the second distillate, and finally the carbon-14-containing waste that is difficult to recover in the waste liquid is separated into solid-liquid two phases, so as to facilitate the subsequent cement solidification.

[0038] It should be noted that the first adsorbent, the first solid, the second solid and the second adsorbent of the present scheme can be directly solidified with cement, the carbon-14 in the first distillation solid residue and the second distillation solid residue can be recycled, and the residual waste liquid obtained after the S6 step can be disposed of in accordance with the national radioactive waste management regulations and the national hazardous waste management regulations.

[0039] Compared with the prior art, this technical solution has the following characteristics and beneficial effects:

[0040] Aiming at the carbon-14 organic waste liquid generated during the carbon-14 labeled synthesis and tracing research of agricultural and pharmaceutical chemicals, this patent provides a pretreatment method for such radioactive organic waste liquid before cement solidification in the later stage, and its beneficial effects are specifically manifested as follows:

[0041] ① Separating most of the radioactive carbon-14 markers in this type of waste liquid from the non-radioactive organic solvent (medium containing carbon-14 substances) that accounts for more than 95% by mass, avoids the problem of destroying the hydration reaction between cement and stone due to the poor compatibility of organic solvents in this type of waste liquid with cement, weakening the bonding force between cement and stone, reducing the maximum carrying capacity of cement solids for radioactive waste, and seriously affecting the hardening ability of cement solids.

[0042] ② Separate most of the radioactive carbon-14 markers in this type of waste liquid from non-radioactive organic solvents (medium containing carbon-14 substances) that account for more than 95% by mass, and achieve volume reduction and quantity reduction of radioactive waste liquid. This not only greatly reduces the amount of radioactive waste disposal, thereby reducing the cost of waste disposal, but also reduces the space occupied by radioactive waste during temporary storage, and reduces safety risks and management costs (for the owner unit); after reducing the volume and quantity of carbon-14 waste liquid, the safety risks and workload of the radioactive waste solidification preparation process are significantly reduced, and the number of packaging containers used is reduced (for radioactive waste preparation units, third-party qualified units); the amount of radioactive waste that must be transported is reduced accordingly (professional transportation companies, third-party qualified units), and transportation costs are reduced; radioactive waste enters the national radioactive waste disposal site, occupies less space, and disposal costs are also greatly reduced (national radioactive waste repository, third-party qualified units). Compared with traditional methods, traditional methods may not be able to effectively separate radioactive substances and organic solvents, resulting in a large total amount of waste liquid that needs to be treated and disposed of, and high costs.

[0043] ③ Adsorb or embed and fix the highly volatile carbon-14 labeled small molecule compounds in this type of waste liquid, and use supercritical water oxidation to convert the volatile carbon-14 labeled small molecule compounds (relative molecular mass less than 100) into inorganic salts to reduce the safety risks of their volatilization, diffusion and spillover to the subsequent cement curing operation and the environment; these treatment measures effectively prevent the volatilization and diffusion of carbon-14 labeled small molecule compounds during the treatment process, reduce the risk of operators inhaling radioactive substances, and protect the health of operators. At the same time, it also avoids the volatilization of radioactive substances into the environment and reduces environmental pollution. In the later cement curing operation, since the volatiles are effectively controlled, they will not interfere with the curing reaction of cement and radioactive waste, ensure the quality and stability of the cement solidified body, and reduce the risk of leakage of radioactive substances. However, traditional methods may lack effective treatment of volatiles, which may easily cause leakage of radioactive substances during the treatment and curing process, endangering the environment and personnel safety.

[0044] ④Recover most of the carbon-14 labeled substances, separate the carbon-14 waste that is difficult to recover in the waste liquid into solid-liquid phases, and facilitate the subsequent cement solidification; the recovered carbon-14 labeled substances can be further processed according to their properties, which improves the utilization rate of resources. The solid substance after the solid-liquid phase separation is easy to mix with cement and other curing agents for solidification treatment because it is stable and easy to operate. The liquid substance can be further processed according to the radioactivity concentration. Traditional methods may not be able to effectively recover the labeled substances, and it is difficult to achieve solid-liquid separation, which brings difficulties to the subsequent cement solidification treatment, affecting the solidification effect and the long-term stability of the radioactive waste cement solidification body.

[0045] ⑤ The radioactivity concentration of the resulting organic waste liquid can be converted to the exemption level. Organic waste liquid with a radioactivity concentration reaching the exemption level can be treated in accordance with the national hazardous waste management regulations. This not only reduces the reliance on specialized radioactive waste disposal facilities and reduces disposal costs, but also reduces the potential harm of radioactive waste to the environment. Traditional methods may find it difficult to reduce the radioactivity of organic waste liquid to the exemption level, resulting in long-term accumulation of waste liquid, increasing environmental risks and management difficulties. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 The figure is a schematic flow chart of a method for treating organic waste liquid containing radioactive isotope carbon-14 according to an embodiment of the present invention. DETAILED DESCRIPTION

[0047] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field belong to the scope of protection of the present invention.

[0048] It is to be understood that the term "one" should be understood as "at least one" or "one or more", that is, in one embodiment, the number of an element may be one, while in another embodiment, the number of the element may be multiple, and the term "one" should not be understood as a limitation on the quantity.

[0049] The technical solution of the present invention is further described in detail below in conjunction with specific implementation methods.

[0050] Example 1: Treatment of Carbon-14-Containing Organic Wastewater Generated in the Synthesis of Carbon-14 Labeled Remdesivir

[0051] Remdesivir is a nucleoside analog with antiviral activity. N , N -Dimethyl[ 14 C] Formamide Preparation of [pyrrolotriazine ring-4- 14 C] Remdesivir, the treatment method of carbon-14 organic waste liquid generated during the synthesis process is as follows:

[0052] Step 1: Use liquid nitrogen to cool the carbon-14 organic waste liquid (2.49 Kg, 4.82E+9 Bq) to -70 ℃~-50 ℃, blow argon into the carbon-14 organic waste liquid, and use a cold trap to capture the carbon-14 substance in the escaping gas at -130 ℃~-100 ℃. After continuous blowing for 3.5 hours, there is no significant radioactivity in the gas escaping from the carbon-14 organic waste liquid. After the blowing is completed, the low-temperature captured material and residual carbon-14 organic waste liquid I (2.49 Kg) are obtained. The captured material A is pumped into the packed high-activity activated carbon column (52 g, specific surface area ≥1200 M 2 / g, particle size 5-10 mesh, moisture content less than 5%); the system to be captured naturally warms to room temperature, the gas in the circulating absorption system of the captured substance A has no significant radioactivity, and the activated carbon A1 (3.85E+7 Bq) that adsorbs carbon-14 substance is temporarily stored.

[0053] Step 2: Use liquid nitrogen to cool the carbon-14 organic waste liquid I (2.49 Kg) to -10-5 °C, blow argon into the carbon-14 organic waste liquid, and use a cold trap to capture the carbon-14 substance in the escaping gas at -130 °C-110 °C. After continuous blowing for 3 hours, the gas escaping from the carbon-14 organic waste liquid has no significant radioactivity. After the blowing is completed, the low-temperature captured substance B and the residual carbon-14 organic waste liquid II (2.49 Kg) are obtained. The captured substance B is pumped into ethanol (120 mL, -20 °C-10 °C) to allow it to be completely dissolved and absorbed, and then sodium stearate (12.3 g) is added thereto, sealed and heated to 50-70 °C, kept warm for 40 minutes, and naturally cooled to room temperature to become solid B1 (107 g, 8.18E+7 Bq), and B1 is stored temporarily.

[0054] Step 3: At 40-50 °C, the carbon-14 organic waste liquid II (2.49 Kg) was distilled at atmospheric pressure, and the carbon-14 substance in the evaporated gas was captured at low temperature (-30--20 °C), and distilled until no distillate was evaporated. After the distillation was completed, the low-temperature captured substance C and the residual carbon-14 organic waste liquid III (2.13 Kg) were obtained. The low-temperature captured substance C (361 g) was treated with a supercritical water oxidation system (with supercritical water / hydrogen peroxide / oxygen as oxidant; 100 mL high-pressure reactor, 30 MPa-35 MPa, 500 °C-600 °C), and the carbon-14 carbon dioxide generated by the system was cyclically absorbed by a barium hydroxide suspension (2.5 Kg of barium hydroxide mixed with 8 L of water). After the absorption was completed, the absorption liquid was concentrated to dry solid C1 (2.68 Kg, 3.95E+8 Bq), and C1 was stored temporarily.

[0055] Step 4: Add granular anhydrous potassium carbonate (80 g) to the carbon-14 organic waste liquid III (1.81 Kg) and stir for 5 hours; stop stirring and distill the mixture to dryness. Recover the distillation solid residue D (197 g, 2.91E+9 Bq) and store it for later use. The obtained distillate IV is processed in the next step.

[0056] Step 5: Pass dry hydrogen chloride gas (about 5-6 L at room temperature) into distillate IV (1.70 Kg), stir for 2 h and then distill to dryness; the distillation residue E (71 g, 1.39E+9 Bq) is temporarily stored for later use, and the obtained distillate V is processed in the next step.

[0057] Step 6: Add a mixture of highly active alumina and activated carbon (weight ratio of 5:1, cumulative addition of 132 g) to the distillate V (1.61 Kg), stir continuously at room temperature for 7 h and then let stand. After filtration, the residual adsorbent F (137 g, 2.91E+7 Bq) and filtrate VI (1.61 Kg, 2.35E+6 Bq) were obtained and stored separately.

[0058] In summary, after being treated by the patented method, liquid radioactive waste (2.49 kg) with complex composition and widely different properties is converted into solid radioactive substances A1, B1, C1, D, E and F. Among them, solid substances D and E can be considered to be recovered and reused in the later stage for carbon-14, and the remaining substances A1, B1, C1 and F are solid, which is convenient for cement solidification in the later stage; the distillate VI can be disposed of in accordance with the national radioactive waste management regulations.

[0059] The present invention is not limited to the above-mentioned optimal implementation mode. Anyone can derive other various forms of products under the inspiration of the present invention. However, no matter what changes are made in the shape or structure, all technical solutions that are the same or similar to those of the present application fall within the protection scope of the present invention.

Claims

1. A method for treating organic waste liquid containing radioactive isotope carbon-14, characterized in that: The following steps are involved: S1: In the temperature range of -70 ℃ to -50 ℃, an inert gas is blown into the carbon-14 organic waste liquid to be treated, and the carbon-14 marker in the escaped gas of the carbon-14 organic waste liquid is captured as the first low-temperature capture material at a temperature below -130 ℃, until there is no obvious radioactivity in the escaped gas to obtain the first carbon-14 organic waste liquid I, and the first low-temperature capture material is pumped into the adsorbent to adsorb the carbon-14 marker and the adsorbent is collected as the first adsorbent; S2: In the temperature range of -10 ℃ to 10 ℃, an inert gas is blown into the first carbon-14 organic waste liquid I, and the carbon-14 marker in the escaped gas of the carbon-14 organic waste liquid is captured as the second low-temperature capture material in the temperature range of -130 ℃ to -100 ℃, until there is no obvious radioactivity in the escaped gas to obtain the second carbon-14 organic waste liquid II, and the second low-temperature capture material is pumped into a low-temperature lower alcohol at room temperature to obtain an alcohol solution, and a carboxylate is added to the alcohol solution, and then the solution is sealed and heated for a period of time, and the first solid is obtained after it is cooled to room temperature; S3: in the temperature range of 40 ℃ to 50 ℃, the second carbon-14 organic waste liquid II is subjected to atmospheric distillation, and the distillate is captured at -30 ℃ to -20 ℃ as the third low-temperature captured material, until there is no distillate to obtain the third carbon-14 organic waste liquid III, the third low-temperature captured material is converted into carbon-14 carbon dioxide by a supercritical water oxidation system, and the carbon-14 carbon dioxide is absorbed by an alkali solution and then decompressed and desolventized to obtain a second solid; S4: adding alkali solution to the third carbon-14 organic waste liquid III and distilling it to obtain a first distillation solid residue and a first distillate; S5: introducing an acidic gas into the first distillate and then distilling it to obtain a second distillation solid residue and a second distillate; S6: Add the adsorbent to the second distillate, stir and let stand until adsorption equilibrium is reached, and separate the solid-liquid phases to obtain the second adsorbent and residual waste liquid.

2. The method for treating organic waste liquid containing radioactive isotope carbon-14 according to claim 1, characterized in that: In step S1, the inert gas is selected from one of argon and nitrogen, and the adsorbent is selected from one of highly active activated carbon, molecular sieve, and alumina, or a combination of two or more thereof.

3. The method for treating organic waste liquid containing radioactive isotope carbon-14 according to claim 1, characterized in that: In step S2, the inert gas is selected from argon and nitrogen.

4. The method for treating organic waste liquid containing radioactive isotope carbon-14 according to claim 1, characterized in that: The lower alcohol in step S2 is an alcohol containing 1 to 4 carbon atoms, the carboxylate is selected from calcium salts or barium salts of carboxylic acids containing 1 to 4 carbon atoms, and sodium salts or potassium salts of carboxylic acids containing 8 to 20 carbon atoms. The heating temperature is 40°C to 80°C, and the heating time is 30 min to 3 h.

5. The method for treating organic waste liquid containing radioactive isotope carbon-14 according to claim 1, characterized in that: The alkali used to prepare the alkali solution in step S3 is selected from barium hydroxide, calcium hydroxide, sodium hydroxide and potassium hydroxide.

6. The method for treating organic waste liquid containing radioactive isotope carbon-14 according to claim 1, characterized in that: The alkali for preparing the alkali solution in step S4 is selected from one or any combination of sodium bicarbonate, sodium carbonate, potassium bicarbonate, potassium carbonate, calcium bicarbonate, calcium carbonate, sodium acetate, calcium acetate, sodium hydroxide, and slaked lime.

7. The method for treating organic waste liquid containing radioactive isotope carbon-14 according to claim 6, characterized in that: The alkali solution is selected to be one or any combination of potassium bicarbonate, sodium carbonate, potassium bicarbonate, and potassium bicarbonate.

8. The method for treating organic waste liquid containing radioactive isotope carbon-14 according to claim 1, characterized in that: The acidic gas in step S5 is selected to be HCl.

9. The method for treating organic waste liquid containing radioactive isotope carbon-14 according to claim 1, characterized in that: The adsorbent in step S6 is selected to be one of activated carbon, silica gel, aluminum oxide, or a mixture of any of several adsorbents.

10. The method for treating organic waste liquid containing radioactive isotope carbon-14 according to claim 1, characterized in that: The first adsorbent, the first solid, the second solid and the second adsorbent are directly solidified with cement, and the carbon-14 in the first distillation solid residue and the second distillation solid residue can be recovered and utilized.

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