Method and device for separating and purifying tritium from tritium-containing wastewater and application thereof

Abstract

The present invention discloses a method, device and application for tritium separation and purification from tritium-containing wastewater. The method includes the following steps: The purified raw water enters the rectification unit for rectification separation. The qualified low-tritium product is obtained at the top of the last rectification column in the rectification unit, and pure tritiated water with a concentration of 99% or more is obtained at the bottom of the first rectification column in the rectification unit. The pure tritiated water and the non-condensable gases from each rectification column are deoxygenated, and then hydrogen isotope separation is carried out to obtain pure tritium gas and other gases. The other gases are oxidized and then sent back to the rectification unit for circulation. In the present invention, water rectification and adsorption separation are organically combined. While reducing the volume of tritium-containing wastewater, the tritium in the wastewater is concentrated and purified to obtain utilizable tritium resources; the operating conditions of the water rectification process are mild, with negative pressure operation and no risk of tritium leakage; the adsorption separation operation process is simple, easy to operate, safe and reliable; it can meet the disposal requirements of large-capacity tritium-containing wastewater and obtain high-purity tritium products.

Description

Technical Field

[0001] The present invention belongs to the technical field of radioactive wastewater treatment, and particularly relates to a method and device for separating and purifying tritium in tritium-containing wastewater and applications thereof. Background Art

[0002] With the development of civil nuclear energy technology, nuclear power, as an important alternative to fossil energy, has attracted increasing attention and emphasis from people, and the installed capacity of global nuclear power units has been continuously increasing. During the operation of nuclear power units, a certain amount of low-level radioactive tritium-containing wastewater is generated, and a certain amount of low-level radioactive tritium-containing wastewater is also generated during the spent fuel reprocessing process. If such tritium-containing wastewater is directly discharged into the external environment, especially into inland water systems, it will have an adverse impact on the environment and public safety. Currently, tritium-containing wastewater has become an important factor restricting the construction of inland nuclear power. Therefore, it is urgent to develop a reliable and stable tritium removal technology for tritium-containing wastewater to reduce the tritium content to the environmental protection discharge standard.

[0003] It should be noted that tritium is a very important nuclear raw material. It is not only an important raw material for controllable nuclear fusion reactors, but also commonly used as a tracer or marker in fields such as medicine, biochemistry, petroleum, environmental protection, and hydrology. At the same time, tritium is also an important raw material for nuclear batteries and has been successfully applied in fields such as aerospace, polar regions, and cardiac pacemakers. Tritium lamps and tritium luminescent devices made of tritium also have the characteristic of long luminous life and can be used in fields such as watches and emergency lights.

[0004] The main methods for separating and concentrating tritium include cryogenic distillation, water rectification, electrolysis, thermal diffusion, solvent extraction, molecular laser method, catalytic exchange method, etc. During the research process, processes and derivative processes that combine two or more methods have emerged. Liquid hydrogen cryogenic rectification is the main means for tritium concentration and purification. In this process, ultra-low temperature separation conditions are required, and liquid hydrogen is used as the separation medium. If directly used to treat tritium in wastewater, a precursor step is needed, or a large amount of hydrogen is used to catalytically exchange tritium in the wastewater into hydrogen gas, or the wastewater is decomposed into hydrogen gas by electrolysis and then liquid hydrogen rectification is carried out. In liquid hydrogen rectification, there are problems of hydrogen embrittlement and hydrogen permeation of hydrogen to a metal material, and high material requirements. Since hydrogen is a flammable and explosive substance and the boiling point of liquid hydrogen is low, the operating conditions of liquid hydrogen rectification are harsh and the treatment throughput is small. The amount of tritium-containing wastewater to be treated is large and the tritium content is low, so it is not suitable to directly use the method of liquid hydrogen rectification for separation and purification. Methods such as electrolysis and thermal diffusion also have the problem of small treatment throughput and are not suitable for directly treating low-level and large-volume tritium-containing wastewater. Among the existing methods above, although the water rectification technology (such as the patent publication number CN208938663U) has a large-capacity treatment ability and is a potentially effective method for reducing the volume of low-concentration tritium-containing wastewater, due to the self-decomposition problem of tritiated water, there is no report on the use of water rectification technology for the purification treatment of tritiated water. Therefore, it is necessary to develop a method that not only has the ability to treat a large volume of low-level tritium-containing wastewater but also has the ability to concentrate and purify tritium, so as to realize the recycling of tritium resources while solving the problem of tritium pollution emissions. Summary of the Invention

[0005] To solve the technical problems existing in the prior art, the purpose of the present invention is to provide a method, device and application for separating and purifying tritium in tritium-containing wastewater.

[0006] To achieve the above purpose and reach the above technical effects, the technical solution adopted by the present invention is as follows:

[0007] A method for separating and purifying tritium in tritium-containing wastewater, comprising the following steps:

[0008] The purified raw water enters the rectification unit and is rectified and separated through the n-stage rectification tower of the rectification unit. The qualified low-tritium discharge is obtained at the top of the last-stage rectification tower of the rectification unit, and pure tritiated water with a concentration of 99% or more is obtained at the bottom of the first-stage rectification tower of the rectification unit. Deoxygenation is carried out on the pure tritiated water and the non-condensable gases from each stage of the rectification tower respectively to obtain hydrogen isotope gas. Hydrogen isotope separation is carried out on the hydrogen isotope gas to obtain pure tritium gas and other gases. The other gases are oxidized and then sent back to the rectification unit, and so on in a cycle to realize the separation and purification of tritium in tritium-containing wastewater.

[0009] Further, n is any integer from 2 to 20. In the rectification unit, after the vapor rising in the (n - 1)-th rectification column reaches the top of the column, it enters the top condenser connected thereto through the top vapor pipe. The condensate is collected in the reflux water tank, and the condensate in the reflux water tank flows into the reboiler at the bottom of the n-th rectification column. After being heated and vaporized, it enters the n-th rectification column. The vapor flows upward. The liquid phase flowing out from the bottom of the n-th rectification column is sent to the reflux port at the upper part of the (n - 1)-th rectification column by an intermediate pump. The liquid flows downward in the (n - 1)-th rectification column and contacts the upward-flowing vapor for heat and mass transfer. After being rectified and separated through multiple rectification columns in sequence, the vapor leaving the top of the last rectification column is condensed by the top condenser connected thereto and then enters the reflux water tank. At this time, the concentration of tritium in the condensate has reached the discharge standard. A part of the condensate returns to the upper reflux port of this rectification column and flows downward, and the other part flows out as the qualified low-tritium product.

[0010] Further, in the pure tritium water flowing out from the bottom of the first rectification column, tritium is concentrated. A part of the liquid flows into the reboiler connected to the first rectification column, is heated and vaporized, and the vapor returns to the bottom of the first rectification column and flows upward. The other part of the liquid enters the concentrated tritium collector for collection after being cooled by the concentrated tritium product cooler. The concentrated tritium water in the concentrated tritium collection tank will decompose spontaneously, generating oxygen and tritium gas. The oxygen and tritium gas are sent to the hydrogen-oxygen gas separation device for oxygen removal, and the gas in the hydrogen-oxygen gas separation device is sent to the adsorption separation device for hydrogen isotope separation.

[0011] Further, the non-condensable gas from each rectification column is the non-condensable gas condensed by the top condenser at the top of the rectification column. The non-condensable gas is sent to the hydrogen-oxygen gas separation device for oxygen removal to obtain hydrogen isotope gas, and then sent to the adsorption separation device for hydrogen isotope separation.

[0012] Further, the adsorption separation device is connected to a carrier gas separation device through a gas switching regulating valve. According to the desorption time of different hydrogen isotope gases, it is switched through the gas switching regulating valve to obtain pure tritium gas with a concentration of more than 99.5%, mixture gas I including T2, DT, D2, HT, and mixture gas II including H2, HD respectively. Mixture gas II is directly discharged, and mixture gas I is sent into the gas oxidation device by a gas transfer pump, catalytically oxidized into hydrogen isotope water, and then sent into the rectification unit.

[0013] Further, after the raw water is deionized and purified by the raw water purification tank, it is sent into the purified water tank. The water in the purified water tank is sent to the feed port of the rectification unit by a feed pump.

[0014] Device for separating and purifying tritium in tritium-containing wastewater, which uses the method for separating and purifying tritium in tritium-containing wastewater to separate and purify tritium in tritium-containing wastewater. The device includes a water rectification unit and an adsorption separation unit. The water rectification unit includes a raw water purification tank, a purified water tank, a concentrated tritium discharge cooler, a concentrated tritium collector and a rectification unit. The rectification unit includes a reboiler, a top condenser, a reflux water tank and an n-stage rectification column, where n is any integer from 1 to 20. A top condenser is provided at the top of each stage of the rectification column. One top condenser is connected to a reflux water tank, and adjacent two stages of the rectification column are connected to each other. The adsorption separation unit includes a hydrogen-oxygen gas separation device, an adsorption separation device, a carrier gas device, a carrier gas separation device, a pure tritium gas collection tank, a gas intermediate tank, a gas oxidation device, a gas switching regulating valve and a hydrogen storage tank. The raw water purification tank is connected to the purified water tank and then to the rectification unit. The bottom of the first-stage rectification column of the rectification unit is connected in sequence to the concentrated tritium discharge cooler, the concentrated tritium collector, the hydrogen-oxygen gas separation device, the hydrogen storage tank, the adsorption separation device and the carrier gas separation device. The adsorption separation device is connected to the carrier gas device. The adsorption separation device is connected to the carrier gas separation device through the gas switching regulating valve. The carrier gas separation device is respectively connected to the pure tritium gas collection tank and the gas intermediate tank. The gas intermediate tank is connected to the gas oxidation device and then to the purified water tank. There is also another path from the bottom of the first-stage rectification column of the rectification unit to the reboiler.

[0015] Further, the purified water tank is connected to the feed port of the rectification unit through a feed pump. The feed port is arranged on the last-stage rectification column of the rectification unit. The gas intermediate tank is connected to the gas oxidation device through a gas delivery pump. The reflux water tank at the top of the upper-stage rectification column is connected to the bottom of the lower-stage rectification column through the reboiler. The bottom of the lower-stage rectification column is connected to the top of the upper-stage rectification column through an intermediate pump.

[0016] The present invention also discloses the application of the device for separating and purifying tritium in tritium-containing wastewater in tritium-containing wastewater.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0018] The present invention discloses a method, device and application for the separation and purification of tritium in tritium-containing wastewater. This method organically combines the water rectification and adsorption separation methods. While reducing the volume of tritium-containing wastewater, the tritium in the wastewater is concentrated and purified to obtain utilizable tritium resources. The method includes the following steps: First, utilize the advantage of high treatment capacity of water rectification to separate and concentrate low-level tritium-containing wastewater, so that the tritium concentration in the wastewater at the stripping end meets the discharge requirements and satisfies the requirements of wastewater treatment. The enrichment end continues to concentrate. During the concentration process, the gas generated by the self-ionization and decomposition of tritiated water is introduced into the adsorption separation unit for adsorption separation to achieve the enrichment and purification of this part of tritium gas, and at the same time solve the safety hazards brought by the decomposition of high-concentration tritiated water during the water rectification process and the problem of decreased separation efficiency caused by non-condensable gas; The water rectification process of the present invention has mild operating conditions, negative pressure operation, no risk of tritium leakage, the adsorption separation operation process is simple, easy to operate, safe and reliable. The organic integration of the above two separation technologies can meet the disposal requirements of large-capacity tritium-containing wastewater, and at the same time, high-purity tritium products can also be obtained. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic structural diagram of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0020] The present invention will be described in detail below so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making the protection scope of the present invention more clearly defined.

[0021] The following gives a brief overview of one or more aspects to provide a basic understanding of these aspects. This overview is not an exhaustive survey of all contemplated aspects, and is neither intended to identify key or decisive elements of all aspects nor to attempt to define the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form as a prelude to a more detailed description to follow.

[0022] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0023] As Figure 1 shown, on the one hand, the present invention provides a method for the separation and purification of tritium in tritium-containing wastewater, including the following steps:

[0024] After the raw water removes ions and impurities through the raw water purification tank 1, it is sent to the purified water tank 2. The water in the purified water tank 2 is sent to the feed inlet of the rectification unit by the feed pump 3 for rectification separation. Water with a tritium concentration lower than the emission standard is obtained at the top of the last stage of the rectification unit and can be directly discharged, while pure tritium water with a concentration of more than 99% is obtained at the bottom of the first stage of the rectification unit. In the top condensers 6 of each stage, non-condensable gases are collected, and then the oxygen in the non-condensable gases is removed through the hydrogen-oxygen gas separation device 11 to obtain hydrogen isotope gas, which is collected in the hydrogen storage tank 20. The carrier gas in the carrier gas device 13 and the gas in the hydrogen storage tank 20 are respectively sent into the adsorption separation device 12, and hydrogen isotope separation is carried out in the adsorption separation device 12. The gas outlet of the adsorption separation device 12 is connected to the carrier gas separation device 14 through the gas switching regulating valve 19. According to the desorption time of different hydrogen isotope gases, switching is carried out through the gas switching regulating valve 19 to respectively obtain pure tritium gas T2 (concentration reaching more than 99.5%), mixed gas I (T2, DT, D2, HT), and mixed gas II (H2, HD). The pure tritium gas T2 is collected in the pure tritium gas collection tank 15, the mixed gas I is collected in the gas intermediate tank 16, and the mixed gas II (H2, HD) is directly discharged; the mixed gas I in the gas intermediate tank 16 is sent into the gas oxidation device 18 by the gas transfer pump 17, and after catalytic oxidation, it becomes hydrogen isotope water and returns to the purified water tank 2 again;

[0025] In the rectification unit, the gas phase rising in the (n - 1)-th stage rectification column 7 reaches the top of the column and then enters the top condenser 6 connected thereto through the top gas phase pipe. The condensate is collected in the reflux water tank 8. The condensate in the reflux water tank 8 flows into the reboiler 4 at the bottom of the n-th stage rectification column 7, is vaporized by heating, and then enters the n-th stage rectification column 7. The steam flows upward; the liquid phase flowing out from the bottom of the n-th stage rectification column 7 is sent to the reflux port at the upper part of the (n - 1)-th stage rectification column 7 by the intermediate pump 5. The liquid flows downward in the (n - 1)-th stage rectification column 7 and contacts the upward flowing steam for heat and mass transfer. After passing through multiple stages of rectification separation in sequence, the gas phase leaving the top of the last stage is condensed by the top condenser 6 connected thereto and then enters the reflux water tank 8. At this time, the tritium concentration in the condensate has reached the emission standard. Therefore, a part of the condensate returns to the upper reflux port of this stage of the rectification column 7 and flows downward, and the other part flows out as qualified materials;

[0026] In the liquid flowing out from the bottom of the first-stage rectification tower 7, tritium is concentrated. A part of the liquid flows into the reboiler 4, is heated and vaporized, and the vapor returns to the bottom of this stage of the tower and flows upward. Another part of the liquid enters the concentrated tritium collector 10 after being cooled by the concentrated tritium discharge cooler 9 and is collected therein. The concentrated tritium water in the concentrated tritium collection tank 10 will decompose spontaneously, generating oxygen and tritium gas. The oxygen and tritium gas are sent into the hydrogen-oxygen gas separation device 11 through a pipeline connected to the hydrogen-oxygen gas separation device 11. Oxygen is removed through the hydrogen-oxygen gas separation device 11, and the remaining gas is collected in the hydrogen storage tank 20. When the concentration of the concentrated tritium water in the concentrated tritium collection tank 10 does not meet the standard, the characteristics of the spontaneous decomposition of the concentrated tritium water can also be utilized, and it enters the adsorption separation device 12 through this pipeline for further purification.

[0027] On the other hand, the present invention also discloses a device for separating and purifying tritium in tritium-containing wastewater, which includes a water rectification unit and an adsorption separation unit. Among them, the water rectification unit includes a raw water purification tank 1, a purified water tank 2, a feed pump 3, a concentrated tritium discharge cooler 9, a concentrated tritium collector 10 and a rectification unit. The rectification unit includes a reboiler 4, a top condenser 6, a reflux water tank 8 and an n-stage rectification tower 7, where n is an integer between 1 and 20. An intermediate pump 5 is arranged between each stage of the rectification tower 7. The adsorption separation unit includes a hydrogen-oxygen gas separation device 11, an adsorption separation device 12, a carrier gas device 13, a carrier gas separation device 14, a pure tritium gas collection tank 15, a gas intermediate tank 16, a gas transfer pump 17, a gas oxidation device 18, a gas switching regulating valve 19, and a hydrogen storage tank 20.

[0028] The raw water purification tank 1 is connected to the purified water tank 2, and the purified water tank 2 is connected to the rectification unit through the feed pump 3. One path at the bottom of the first-stage rectification tower 7 of the rectification unit is successively connected to the concentrated tritium discharge cooler 9, the concentrated tritium collector 10, the hydrogen-oxygen gas separation device 11, the hydrogen storage tank 20, the adsorption separation device 12, and the carrier gas separation device 14. Another path at the bottom of the first-stage rectification tower 7 of the rectification unit is also connected to the reboiler 4. The top of the first-stage rectification tower 7 is connected to the top condenser 6, and the top condenser 6 is connected to the reflux water tank 8. The reflux water tank 8 at the top of the upper-stage rectification tower 7 is connected to the bottom of the lower-stage rectification tower 7 through the reboiler 4, that is, the reflux water tank 8 at the top of the first-stage rectification tower 7 is connected to the bottom of the second-stage rectification tower 7 through the reboiler 4, and the reflux water tank 8 at the top of the second-stage rectification tower 7 is connected to the bottom of the third-stage rectification tower 7 through the reboiler 4, and so on. The carrier gas device 13 is connected to the gas inlet of the adsorption separation device 12. The gas outlet of the adsorption separation device 12 is connected to the carrier gas separation device 14 through the gas switching regulating valve 19. The carrier gas separation device 14 is respectively connected to the pure tritium gas collection tank 15 and the gas intermediate tank 16. The gas intermediate tank 16 is connected to the gas oxidation device 18 through the gas transfer pump 17 and then connected to the purified water tank 2.

[0029] Example 1

[0030] The rectification unit includes a 4-stage rectification column 7 with 4-column liquid-phase cascade, a throughput of 500 kg / h, and an operating pressure of 500 mmHg; the tritium concentration in the low-level tritium-containing wastewater is 1.5×10 9 Bq / L. The tritium concentration in the material taken from the top of the fourth stage is 95.8 Bq / L, and the tritium concentration in the material discharged from the bottom of the first stage is 99.3%. Tritium is concentrated. Part of the liquid flows into the reboiler 4, is heated and vaporized, and the steam returns to the bottom of this stage and flows upward. Another part of the liquid enters the concentrated tritium collector 10 after being cooled by the concentrated tritium discharge cooler 9. The concentrated tritium water in the concentrated tritium collection tank 10 will decompose spontaneously, generating oxygen and tritium gas. The oxygen and tritium gas are sent into the hydrogen-oxygen gas separation device 11 through a pipeline connected to the hydrogen-oxygen gas separation device 11. Oxygen is removed through the hydrogen-oxygen gas separation device 11, and the remaining gas is collected in the hydrogen storage tank 20. The carrier gas in the carrier gas device 13 and the gas in the hydrogen storage tank 20 are respectively sent into the adsorption separation device 12. Hydrogen isotope separation is carried out in the adsorption separation device 12. The gas outlet of the adsorption separation device 12 is connected to the carrier gas separation device 14 through the gas switching regulating valve 19. According to the desorption time of different hydrogen isotope gases, switching is carried out through the gas switching regulating valve 19 to obtain pure tritium gas T2 (concentration reaching 99.5%), mixed gas Ⅰ (T2, DT, D2, HT), and mixed gas Ⅱ (H2, HD) respectively. The pure tritium gas T2 is collected in the pure tritium gas collection tank 15, the mixed gas Ⅰ is collected in the gas intermediate tank 16, and the mixed gas Ⅱ (H2, HD) is directly discharged. The mixed gas Ⅰ in the gas intermediate tank 16 is sent into the gas oxidation device 18 by the gas transfer pump 17, is catalytically oxidized into hydrogen isotope water, and then returns to the purification water tank 2 again.

[0031] The present invention also discloses the application of the device for separating and purifying tritium in tritium-containing wastewater in the treatment of tritium-containing wastewater.

[0032] For the parts or structures not specifically described in the present invention, existing technologies or existing products can be adopted, and no further elaboration will be made here.

[0033] The above are only the embodiments of the present invention, and do not limit the patent scope of the present invention accordingly. Any equivalent structural or equivalent process transformation made by using the content of the specification of the present invention, or directly or indirectly applied in other related technical fields, shall be similarly included in the patent protection scope of the present invention.

Claims

1. A method for separating and purifying tritium from tritium-containing wastewater, characterized in that, It includes the following steps: The purified raw water enters the rectification unit and is rectified and separated by the n-stage rectification column in the rectification unit. The qualified low-tritium product is obtained at the top of the last-stage rectification column in the rectification unit, and the pure tritiated water with a concentration of 99% or more is obtained at the bottom of the first-stage rectification column in the rectification unit. The pure tritiated water and the non-condensable gases from each stage of the rectification column are deoxygenated respectively to obtain hydrogen isotope gases. The hydrogen isotope gases are separated to obtain pure tritium gas and other gases. The other gases are oxidized and then sent back to the rectification unit for circulation.

2. The method for separating and purifying tritium from tritium-containing wastewater according to claim 1, wherein n is any integer from 2 to 20. In the rectification unit, after the gas phase rising in the (n - 1)-th stage rectification column reaches the top of the column, it enters the top condenser connected thereto, and the condensate is collected in the reflux water tank. The condensate in the reflux water tank flows into the reboiler at the bottom of the n-th stage rectification column, is vaporized by heating and then enters the n-th stage rectification column. The steam flows upward. The liquid phase flowing out from the bottom of the n-th stage rectification column is sent to the reflux port at the upper part of the (n - 1)-th stage rectification column, and the liquid flows downward in the (n - 1)-th stage rectification column and contacts the upward-flowing gas phase for heat transfer and mass transfer. After being rectified and separated by multiple rectification columns in sequence, the gas phase leaving from the top of the last-stage rectification column is condensed by the top condenser connected thereto and then enters the reflux water tank. At this time, the concentration of tritium in the condensate has reached the discharge standard. A part of the condensate returns to the upper reflux port of this stage of the rectification column and flows downward, and the other part flows out as the qualified low-tritium product.

3. The method for separating and purifying tritium from tritium-containing wastewater according to claim 1, wherein In the pure tritiated water flowing out from the bottom of the first-stage rectification column, tritium is concentrated. A part of the liquid flows into the reboiler connected to the first-stage rectification column, is vaporized by heating, and the steam returns to the bottom of the first-stage rectification column and flows upward. The other part of the liquid is cooled by the concentrated tritium product cooler and then enters the concentrated tritium collector for collection. The concentrated tritiated water in the concentrated tritium collection tank will decompose spontaneously to generate oxygen and tritium gas. The oxygen and tritium gas are sent to the hydrogen-oxygen gas separation device for deoxygenation, and the gas in the hydrogen-oxygen gas separation device is sent to the adsorption separation device for hydrogen isotope separation.

4. The method for separating and purifying tritium from tritium-containing wastewater according to claim 1, wherein The non-condensable gases from each stage of the rectification column are the non-condensable gases condensed by the top condenser at the top of the rectification column. The non-condensable gases are sent to the hydrogen-oxygen gas separation device for deoxygenation to obtain hydrogen isotope gases, and then sent to the adsorption separation device for hydrogen isotope separation.

5. The method for separating and purifying tritium from tritium-containing wastewater according to claim 4, wherein The adsorption separation device is connected to a carrier gas separation device through a gas switching regulating valve. According to the desorption time of different hydrogen isotope gases, it is switched through the gas switching regulating valve to obtain pure tritium gas with a concentration of more than 99.5%, mixture gas I including T2, DT, D2, HT, and mixture gas II including H2, HD. The mixture gas II is directly discharged, and the mixture gas I is sent into the gas oxidation device, catalytically oxidized into hydrogen isotope water, and then sent back to the rectification unit.

6. The method for separating and purifying tritium from tritium-containing wastewater according to claim 1, wherein The raw water is sent to the purified water tank after removing ions and impurities through the raw water purification tank. The water in the purified water tank is sent to the feed port of the rectification unit by a feed pump.

7. A device for separating and purifying tritium from tritium-containing wastewater, characterized in that, The method for separating and purifying tritium in tritium-containing wastewater described in any one of claims 1-6 is used for separating and purifying tritium in tritium-containing wastewater. The device includes a water rectification unit and an adsorption separation unit. The water rectification unit includes a raw water purification tank, a purified water tank, a concentrated tritium discharge cooler, a concentrated tritium collector and a rectification unit. The rectification unit includes a reboiler, a top condenser, a reflux water tank and an n-stage rectification column, where n is any integer from 1 to 20. A top condenser is provided at the top of each stage of the rectification column. One top condenser is connected to a reflux water tank, and adjacent two-stage rectification columns are connected to each other. The adsorption separation unit includes a hydrogen-oxygen gas separation device, an adsorption separation device, a carrier gas device, a carrier gas separation device, a pure tritium gas collection tank, a gas intermediate tank, a gas oxidation device, a gas switching regulating valve and a hydrogen gas storage tank. The raw water purification tank is connected to the purified water tank and then to the rectification unit. The bottom of the first-stage rectification column of the rectification unit is connected in sequence to the concentrated tritium discharge cooler, the concentrated tritium collector, the hydrogen-oxygen gas separation device, the hydrogen gas storage tank, the adsorption separation device and the carrier gas separation device. The adsorption separation device is connected to the carrier gas device. The adsorption separation device is connected to the carrier gas separation device through the gas switching regulating valve. The carrier gas separation device is respectively connected to the pure tritium gas collection tank and the gas intermediate tank. The gas intermediate tank is connected to the gas oxidation device and then to the purified water tank. There is another path from the bottom of the first-stage rectification column of the rectification unit to the reboiler; The raw water purification tank is connected to the purified water tank. The purified water tank is connected to the feed port of the rectification unit through a feed pump. The feed port is arranged on the last-stage rectification column of the rectification unit. The gas intermediate tank is connected to the gas oxidation device through a gas transfer pump. The gas oxidation device is connected to the purified water tank. The reflux water tank at the top of the upper-stage rectification column is connected to the bottom of the lower-stage rectification column through the reboiler. The bottom of the lower-stage rectification column is connected to the top of the upper-stage rectification column through an intermediate pump.

8. Application of the device for separating and purifying tritium in tritium-containing wastewater according to claim 7 in tritium-containing wastewater.

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