A method for separating tritium in tritium-containing wastewater and a reactor system and application thereof

Abstract

The present application relates to a kind of tritium separation method of tritium-containing wastewater and its reactor system, application, the tritium separation method of tritium-containing wastewater of the present application is ultraviolet irradiation promotes separation method, comprising: step 1) tritium-containing wastewater is introduced into the reaction containment of reactor system and is contacted with adsorption material to form liquid-solid two-phase contact system, step 2) after ultraviolet light is irradiated to liquid-solid two-phase contact system, make tritium enrich in adsorption material;Step 3) after the liquid-solid two-phase contact system of irradiation is completed, solid-liquid separation is obtained to low concentration tritium treatment water and tritium-rich adsorption material.The method of the present application is irradiated by ultraviolet light, accelerates hydrogen / tritium isotope exchange and adsorption process, can obtain higher tritium removal rate and adsorption amount under the same processing time.The present application belongs to energy-saving and environmental protection industry, especially in wastewater environmental control and nuclear pollution wastewater treatment in the environmental protection application of the recovery treatment of nuclear radioactive pollution elements plays a key role.

Description

Technical Field

[0001] This invention relates to the field of tritium separation and nuclear wastewater treatment technology, belonging to the energy conservation and environmental protection industry, especially the environmental protection field of nuclear contaminated wastewater treatment, specifically involving a method for separating tritium from tritium-containing wastewater, its reactor system, and its application. Background Technology

[0002] Nuclear power plants, research reactors, and isotope production facilities generate large amounts of tritium-containing liquid effluents during operation and decommissioning. Tritium mainly exists in the form of water tritide (HTO or T2O), whose physicochemical properties are very similar to ordinary water, with very little difference in boiling point, melting point, vapor pressure, and chemical reactivity. This makes it difficult for traditional physical separation techniques to efficiently separate tritium from water under economically feasible conditions.

[0003] Furthermore, tritium is not only an environmental risk factor but also an important energy and tracer resource, applicable to fields such as tritium-volt batteries and medical tracers. Existing patents have proposed using tritium-volt water-based zinc-ion batteries to achieve the conversion and storage of radiative energy into electrical energy and chemical energy, demonstrating the significant resource utilization value of efficiently and cost-effectively recovering tritium from tritium-containing wastewater. Therefore, developing a new method to significantly accelerate isotope exchange between tritium and adsorbent materials and improve tritium enrichment efficiency under mild conditions is of great importance for reducing tritium-containing wastewater discharge and recovering tritium resources.

[0004] Currently, the main technologies used internationally for tritium separation include: cryogenic distillation and its isotope distillation processes; electrolysis or electrolysis-distillation combination processes; catalytic isotope exchange and distillation combination processes; and emerging technologies such as gas diffusion and liquid membrane separation. These technologies can achieve high separation factors under high-concentration tritium or small-scale operating conditions, but they generally suffer from problems such as complex equipment, high energy consumption, high operating costs, and slow response during start-up and shutdown. For low- to medium-concentration tritium-containing wastewater with activity levels ranging from 0.01 to 100 MBq / L, conventional technologies struggle to balance treatment depth and economic efficiency, and existing adsorption / isotope exchange tritium removal technologies suffer from slow kinetics, long contact times, and large equipment size. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of existing technologies in treating low-concentration tritium-containing wastewater with activity levels ranging from 0.01 to 100 MBq / L, which struggle to balance treatment depth and economy. Furthermore, existing adsorption / isotope exchange tritium removal technologies suffer from slow kinetics, long contact times, and large device size. This invention provides a method for separating tritium from tritium-containing wastewater, along with its reactor system and applications. The separation method employs ultraviolet light irradiation to promote separation, significantly improving the tritium removal rate and adsorption capacity per unit time while maintaining a mild process and simple equipment. This invention belongs to the advanced environmental protection industry within the energy conservation and environmental protection sector, playing a crucial role in the environmental protection application of nuclear wastewater recovery and treatment in nuclear pollution prevention, particularly in the recovery and treatment of radioactive contaminants in environmental control and pollution remediation.

[0006] On one hand, the present invention provides a method for separating tritium from tritium-containing wastewater, wherein the separation method is an ultraviolet light irradiation-promoted separation method, comprising the following steps: Step 1): The tritium-containing wastewater to be treated is introduced into the reaction container of the reactor system and comes into contact with the adsorbent material in the reaction container. The reaction is carried out at 20~40℃ for 0.5~4h to form a liquid-solid two-phase contact system. The mass of tritium-containing wastewater added is 2 to 30 times the mass of the adsorbent material in the reaction container; The adsorbent material is an adsorbent material containing hydrogen-containing functional groups that can participate in hydrogen / tritium isotope exchange and / or an adsorbent material containing sulfonic acid groups. Step 2): Turn on the ultraviolet light source of the reactor system and emit ultraviolet light with a wavelength of 200-300 nm. The ultraviolet light irradiates the liquid-solid two-phase contact system for 12-72 hours. After irradiation, tritium is enriched in the adsorbent material. Step 3): After irradiation, the liquid-solid two-phase contact system is subjected to solid-liquid separation to obtain low-concentration tritium-treated water and tritium-rich adsorbent material; Step 4): The tritium-rich adsorbent material is desorbed or calcined to recover tritium and obtain regenerated adsorbent material. The regenerated adsorbent material is used for recycling in Step 1); the low-concentration tritium-treated water is discharged in compliance with standards, reused, or subjected to deep tritium removal treatment.

[0007] Furthermore, in the tritium separation method for tritium-containing wastewater described in this invention, the center wavelength of the ultraviolet light source is 100–400 nm.

[0008] Furthermore, in the tritium separation method for tritium-containing wastewater described in this invention, the tritium-containing wastewater is a tritium-containing liquid effluent from a nuclear power plant, research reactor, isotope production device, or reactor decommissioning process, and the tritium activity concentration of the tritium-containing wastewater is greater than or equal to 0.01 MBq / L.

[0009] Furthermore, in the tritium separation method for tritium-containing wastewater of the present invention, in step 1), the adsorbent is a hydrogen-functionalized adsorbent, which is a hydroxyl-containing hydrophilic polymer, and the structure of the hydroxyl-containing hydrophilic polymer contains at least one of the functional groups -OH, -CH2OH or -CH(OH)-.

[0010] Furthermore, in step 1), the mass of the tritium-containing wastewater added is 2 to 30 times the mass of the hydrogen-containing functional group adsorbent material in the reaction container.

[0011] Furthermore, in the tritium separation method for tritium-containing wastewater described in this invention, the hydroxyl-containing hydrophilic polymer material is polyvinyl alcohol.

[0012] Furthermore, in the tritium separation method for tritium-containing wastewater of the present invention, in step 1), the adsorbent is a sulfonic acid-based adsorbent, which is an ion exchange resin containing sulfonic acid groups, and the ion exchange resin is at least one of a sulfonic acid-type strong acid cation exchange resin or a modified product of a sulfonic acid-type strong acid cation exchange resin.

[0013] Furthermore, in step 1), the mass of the tritium-containing wastewater added is 2 to 10 times the mass of the sulfonic acid-based adsorbent material added to the reaction container.

[0014] Furthermore, in the tritium separation method for tritium-containing wastewater described in this invention, the liquid-solid two-phase contact system is an intermittent stirring system or a continuous flow fixed bed system.

[0015] Furthermore, in intermittent stirring systems, sufficient solid-liquid contact is maintained through mechanical stirring or gas bubbling.

[0016] Furthermore, the solid-liquid separation method described in step 3) is centrifugal separation or vacuum filtration separation.

[0017] This invention selects a polymeric adsorbent material rich in hydrogen-containing functional groups or ion-exchange groups, ensuring sufficient contact with tritium-containing water. Operating under ultraviolet light irradiation at wavelengths of 200–300 nm generates active free radicals and excited-state groups on the surface of the adsorbent material and in the interfacial water, enhancing the hydrogen / tritium isotope exchange rate. By appropriately controlling the ultraviolet light intensity, irradiation time, and solid-liquid ratio, this invention preferentially enriches tritium in the adsorbent material, thereby improving the tritium removal rate and the amount adsorbed per unit mass.

[0018] On the other hand, the present invention provides a reactor system for a method of separating tritium from tritium-containing wastewater. The reactor system includes: a reaction container, an ultraviolet light source, a liquid-solid two-phase contact system maintenance mechanism, an outlet pipe, and an inlet pipe. The ultraviolet light source is disposed outside the reaction container, the outlet pipe is connected to the treated water outlet of the reaction container, and the inlet pipe is connected to the wastewater inlet of the reaction container. The liquid-solid two-phase contact system maintenance mechanism is a stirring unit or a circulation unit. The stirring unit is located inside the reaction container, and the circulation unit is connected to the reaction container. The inner cavity of the reaction container can accommodate tritium-containing wastewater and adsorption material, and the wall material of the reaction container is selected from one or more of quartz, borosilicate glass or fluoropolymer. The reactor system is used for the tritium separation method in any of the above-described tritium-containing wastewater.

[0019] Furthermore, in the reactor system used in the method for separating tritium from tritium-containing wastewater according to the present invention, the circulation unit of the reactor includes a circulation pump, a circulation guide pipe connected to the reaction container, a liquid distributor disposed at the inlet end of the reaction container, and a filter component disposed at the outlet end of the reaction container; the circulation pump drives the tritium-containing wastewater in the reaction container to flow out from the bottom of the reaction container and return to the upper part of the reaction container through the circulation guide pipe.

[0020] The present invention also proposes a reactor system for promoting tritium separation by ultraviolet light irradiation to complement the method. It can be designed as an intermittent or continuous structure as needed, and can be used in conjunction with existing fixed bed adsorption, resin exchange or membrane separation units.

[0021] In another aspect, the present invention also provides an application of a method for separating tritium in tritium-containing wastewater, wherein the method for separating tritium in tritium-containing wastewater is any of the above-mentioned methods for separating tritium in tritium-containing wastewater, and the separation method is applied to the reduction of tritium-containing wastewater or the recovery of tritium resources generated by nuclear power plants, research reactors, isotope production or nuclear facilities.

[0022] The beneficial effects of this invention are: The present invention provides a method for separating tritium from tritium-containing wastewater, its reactor system, and its application, which, compared with the prior art, have the following advantages: (1) Significantly improves tritium separation kinetics. By irradiating with ultraviolet light, more active hydrogen-containing sites and free radical species are induced at the interface between the adsorbent material and tritium-containing water, which accelerates the hydrogen / tritium isotope exchange and adsorption process, significantly shortens the time required to reach isotope equilibrium, and can obtain good tritium removal rate and higher adsorption capacity under the same treatment time.

[0023] (2) The process conditions are mild and the equipment is simple. The method of the present invention operates under normal pressure and low temperature conditions, requiring only the addition of an ultraviolet light source and a light-transmitting reactor. It does not require high-temperature and high-pressure equipment or complex distillation columns, making it easy to modify or connect in series in existing nuclear wastewater treatment systems.

[0024] (3) Flexible material types and compatibility with existing adsorption systems. The selected adsorption materials can be hydrophilic polymers such as polyvinyl alcohol, or industrially mature sulfonic acid ion exchange resins, which facilitates the use of existing material systems and regeneration processes, reducing the difficulty of research and development and engineering scale-up.

[0025] (4) It has both emission reduction and resource recovery functions. Tritium-rich adsorbent materials can recover tritium through desorption or calcination, realizing the reduction of tritium-containing wastewater and the enrichment of tritium resources, providing raw materials for the subsequent preparation of high-value-added products such as tritium batteries. Furthermore, this invention belongs to the advanced environmental protection industry within the energy conservation and environmental protection industry, playing an important role in the environmental protection application of nuclear wastewater recycling and treatment in nuclear pollution prevention and control, especially in the recovery and treatment of nuclear radioactive pollutants in environmental control and pollution treatment. Attached Figure Description

[0026] Figure 1 This is a bar chart comparing the tritium removal rate and adsorption amount of Example 1 and Comparative Example 1 of the present invention. Figure 2 This is a bar chart comparing the tritium removal rate and adsorption amount of Comparative Example 2 of the present invention; Figure 3 This is a bar chart comparing the tritium removal rate and adsorption amount of Example 3 and Comparative Example 3 of the present invention. Figure 4 This is a bar chart comparing the tritium removal rate and adsorption amount of Example 4 and Comparative Example 4 of the present invention. Figure 5 This is a bar chart comparing the tritium removal rate and adsorption amount of Example 5 and Comparative Example 5 of the present invention. Figure 6 This is a bar chart comparing the tritium removal rate and adsorption amount of Example 6 and Comparative Example 6 of the present invention. Figure 7 An optical photograph of the PVA adsorbent material particles in Example 1 of this invention; Figure 8 This is a SEM image of the PVA adsorbent material particles in Example 1 of the present invention. Detailed Implementation

[0027] To provide a clearer understanding of the technical features, objectives, and effects of the present invention, specific embodiments are now described in detail with reference to the accompanying drawings. The described embodiments are merely some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention. Where specific conditions are not specified in the detailed embodiments, conventional conditions or conditions provided by the manufacturer shall apply.

[0028] In the following description, when referring to the accompanying drawings, the same numbers in different drawings denote the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this disclosure. The terminology used in this disclosure is for the purpose of describing particular embodiments only and is not intended to be limiting of this disclosure.

[0029] The present invention will be further described in detail below with reference to specific embodiments.

[0030] Example 1 The present invention discloses a method for separating tritium from tritium-containing wastewater. The separation method is an ultraviolet light irradiation-promoted separation method, comprising the following steps: Step 1): The tritium-containing wastewater is a liquid effluent from a nuclear power plant, with an initial tritium activity of 0.65 MBq / L. 2.5 g of polyvinyl alcohol solid adsorbent is added to the reaction vessel, and 50 g of tritium-containing wastewater is introduced into the reaction vessel to contact with the adsorbent in the reaction vessel. The mixture is heated at 25±2℃ with stirring to allow it to react fully for 2 h, thus obtaining a liquid-solid two-phase contact system with a PVA mass fraction of 5 wt%.

[0031] The adsorbent material is polyvinyl alcohol (PVA, analytical grade, Maclean, type 1799), such as... Figure 7 and Figure 8 As shown, the reactor is a quartz reaction vessel that can transmit 254 nm ultraviolet light.

[0032] Step 2): Turn on the ultraviolet light source of the reactor system to emit ultraviolet light with a wavelength of 254 nm. Irradiate the liquid-solid two-phase contact system with ultraviolet light for 48 hours at 25°C while keeping the system stirred. After the irradiation is completed, stop stirring and ultraviolet light irradiation, and cool the solution to room temperature to enrich tritium in the adsorbent material.

[0033] Step 3): After irradiation, the liquid-solid two-phase contact system was subjected to solid-liquid separation using an ultrafiltration membrane with a molecular weight cutoff of 30,000 Da, centrifuged at 8000 r / min for 30 min. Low-concentration tritium-treated water and tritium-rich adsorbent material were obtained. The tritium activity of the separated liquid phase (low-concentration tritium-treated water) was measured, and the tritium removal rate and adsorption capacity per unit mass were calculated. The results are as follows: Figure 1 As shown.

[0034] Step 4): Desorb or calcine the tritium-rich adsorbent material to recover tritium and obtain regenerated adsorbent material. The regenerated adsorbent material is used for recycling in Step 1); low-concentration tritium-treated water is discharged in compliance with standards, reused, or undergoes deep tritium removal treatment.

[0035] Example 2 The present invention discloses a method for separating tritium from tritium-containing wastewater. The separation method is an ultraviolet light irradiation-promoted separation method, comprising the following steps: Step 1): The tritium-containing wastewater is a liquid effluent from a nuclear power plant, with an initial tritium activity of 0.65 MBq / L. Sulfonic acid-type strong acid cation exchange resin adsorbent is added to the tritium-containing wastewater. The tritium-containing wastewater is then introduced into a reaction container and brought into contact with the adsorbent in the reaction container. The mixture is heated at 25±2℃ with stirring to allow it to react fully for 2 hours. The mass ratio of sulfonic acid-type strong acid cation exchange resin to tritium-containing wastewater is 1:3.

[0036] The adsorbent material was a commercial sulfonic acid-type strong acid cation exchange resin, which was pretreated by acid washing and water washing before use. The reactor was a quartz reaction vessel that could transmit 254 nm ultraviolet light. In this Example 2, the commercial sulfonic acid-type strong acid cation exchange resin was purchased from Guangdong Fangxin Biotechnology Co., Ltd. as perfluorosulfonic acid resin (-H), with an analytical purity of 98%.

[0037] Step 2): Turn on the ultraviolet light source of the reactor system to emit ultraviolet light with a wavelength of 254 nm. Irradiate the liquid-solid two-phase contact system with ultraviolet light for 48 hours at 25°C while keeping the system stirred. After the irradiation is completed, stop stirring and ultraviolet light irradiation, and cool the solution to room temperature to enrich tritium in the adsorbent material. Step 3): After irradiation, the liquid-solid two-phase contact system was subjected to solid-liquid separation using an ultrafiltration membrane with a molecular weight cutoff of 30,000 Da, centrifuged at 8000 r / min for 30 min. Low-concentration tritium-treated water and tritium-rich adsorbent material were obtained. The tritium activity of the separated liquid phase (low-concentration tritium-treated water) was measured, and the tritium removal rate and adsorption capacity per unit mass were calculated. The results are as follows: Figure 2 As shown.

[0038] Step 4): The tritium-rich adsorbent material is desorbed or calcined to recover tritium, resulting in regenerated adsorbent material. This regenerated adsorbent material is then recycled in Step 1). ； Low-concentration tritium treated water is discharged in compliance with standards, reused, or subjected to advanced tritium removal treatment.

[0039] Example 3 The only difference between Example 3 and Example 1 is that in step 1), the mass of the tritium-containing wastewater added is 10 times the mass of the adsorbent material added, and 5g of polyvinyl alcohol solid adsorbent material is added; the stirring method is magnetic stirring at a speed of 300r / min; in step 1), a liquid-solid two-phase contact system with a PVA mass fraction of 10 wt% is obtained; in step 3), a sample of the separated liquid phase (low-concentration tritium-treated water) is taken to determine its tritium activity, and the tritium removal rate and adsorption capacity per unit mass are calculated. The results are as follows: Figure 3 As shown.

[0040] Example 4 The only difference between Example 4 and Example 1 is that in step 1), the mass of tritium-containing wastewater added is 50 times the mass of adsorbent material added, and 1g of polyvinyl alcohol solid adsorbent material is added; the stirring method is magnetic stirring at a speed of 300r / min; in step 1), a liquid-solid two-phase contact system with a PVA mass fraction of 2wt% is obtained; in step 3), a sample of the separated liquid phase (low-concentration tritium-treated water) is taken to determine its tritium activity, and the tritium removal rate and adsorption capacity per unit mass are calculated. The results are as follows: Figure 4 As shown.

[0041] Example 5 The only difference between Example 5 and Example 2 is that in step 1), the added mass of tritium-containing wastewater is 50 g, and the added mass of sulfonic acid-type strong acid cation exchange resin adsorbent is 25 g, i.e., the mass ratio of sulfonic acid-type strong acid cation exchange resin to tritium-containing wastewater is 1:2; the stirring method is mechanical stirring at a speed of 250 r / min; the mass ratio of sulfonic acid-type strong acid cation exchange resin to tritium-containing wastewater is 1:3; in step 3), a sample of the separated liquid phase (low-concentration tritium-treated water) is taken to determine its tritium activity, and the tritium removal rate and adsorption capacity per unit mass are calculated. The results are as follows: Figure 5 As shown.

[0042] Example 6 The only difference between Example 6 and Example 2 is that in step 1), the added mass of tritium-containing wastewater is 50 g, and the added mass of sulfonic acid-type strong acid cation exchange resin adsorbent is 10 g, i.e., the mass ratio of sulfonic acid-type strong acid cation exchange resin to tritium-containing wastewater is 1:5; the stirring method is mechanical stirring at a speed of 250 r / min; in step 3), a sample of the separated liquid phase (low-concentration tritium-treated water) is taken to determine its tritium activity, and the tritium removal rate and adsorption capacity per unit mass are calculated. The results are as follows: Figure 6 As shown.

[0043] Example 7 The only difference between Example 7 and Example 1 is that in step 1), the added mass of tritium-containing wastewater is 50 g, and the added mass of polyvinyl alcohol solid adsorbent is 2.5 g, that is, the mass ratio of polyvinyl alcohol solid adsorbent to tritium-containing wastewater is 1:20; the stirring method is magnetic stirring, and the rotation speed is 300 r / min; in step 2), the ultraviolet light source is a low-pressure mercury lamp with a center wavelength of 254 nm and a light intensity of 2 mW / cm²; in step 3), the tritium activity of the separated liquid phase (low-concentration tritium-treated water) sample is measured, and the tritium removal rate and adsorption capacity per unit mass are calculated.

[0044] Example 8 The only difference between Example 8 and Example 1 is that in step 1), the added mass of tritium-containing wastewater is 50 g, and the added mass of polyvinyl alcohol solid adsorbent is 2.5 g, that is, the mass ratio of polyvinyl alcohol solid adsorbent to tritium-containing wastewater is 1:20; the stirring method is magnetic stirring, and the speed is 300 r / min; in step 3), the tritium activity of the separated liquid phase (low-concentration tritium-treated water) sample is measured, and the tritium removal rate and adsorption capacity per unit mass are calculated.

[0045] Comparative Example 1 The only difference between this comparative example and Example 1 is that the ultraviolet light source is not turned on in step 3), and the reaction is carried out under the same temperature conditions for 48 hours. Finally, separation and detection are performed according to the method of Example 1, and the results are as follows. Figure 1 As shown.

[0046] Comparative Example 2 The only difference between this comparative example and Example 2 is that the ultraviolet light source is not turned on in step 3), and the reaction is carried out at the same temperature for 48 hours. Finally, separation and detection are performed according to the method of Example 2, and the results are as follows. Figure 2 As shown.

[0047] Comparative Example 3 The only difference between this comparative example and Example 3 is that the mass ratio of polyvinyl alcohol to tritium-containing water is 1:5. Finally, separation and detection were performed according to the method of Example 3, and the results are as follows. Figure 3 As shown.

[0048] Comparative Example 4 The only difference between this comparative example and Example 4 is that the mass ratio of polyvinyl alcohol to tritium-containing water is 1:100. Finally, separation and detection were performed according to the method of Example 4, and the results are as follows. Figure 4 As shown.

[0049] Comparative Example 5 The only difference between this comparative example and Example 5 is that the mass ratio of sulfonic acid resin to tritium-containing water is 1:1. Finally, separation and detection were performed according to the method of Example 5, and the results are as follows. Figure 5 As shown.

[0050] Comparative Example 6 The only difference between this comparative example and Example 6 is that the mass ratio of sulfonic acid resin to tritium-containing water is 1:10. Finally, separation and detection were performed according to the method of Example 5, and the results are as follows. Figure 5 As shown.

[0051] Comparative Example 7 The only difference between this comparative example and Example 7 is that the intensity of the ultraviolet light source was adjusted to 1 mW / cm². Finally, separation and detection were performed according to the method of Example 7.

[0052] Comparative Example 8 The only difference between this comparative example and Example 8 is that the ultraviolet light irradiation time was adjusted to 12 h. Finally, separation and detection were performed according to the method of Example 8.

[0053] Comparative Example 9 The difference between this comparative example and Example 1 is that no adsorbent material was added. Finally, separation and detection were performed according to the method of Example 1.

[0054] like Figures 1-8 As shown, the green bars represent the detection results of Comparative Examples 1-6, and the purple bars represent the detection results of Examples 1-6. Compared with Comparative Example 1, the tritium removal rate of tritium-containing water in Example 1 increased from 5.1% to 15.3%, and the adsorption capacity per unit mass calculated based on PVA dosage increased from 3300 Bq / g to 9900 Bq / g. The results indicate that, under the same conditions, ultraviolet light irradiation can significantly promote the enrichment and separation process of tritium in the polyvinyl alcohol system, and improve the tritium removal rate and enrichment capacity per unit mass of the system.

[0055] Compared with Comparative Example 2, the tritium removal rate in Example 2 increased from 20.1% to 30.0%, and the adsorption capacity per unit mass, calculated based on the amount of sulfonic acid resin added, increased from 435 Bq / g to 648 Bq / g. The results indicate that, under the same conditions, ultraviolet irradiation can effectively improve the tritium separation efficiency of the sulfonic acid resin system and enhance the resin's enrichment effect on tritium.

[0056] Compared with Comparative Example 3, the tritium removal rate of the tritium-containing water in Example 3 decreased from 18.06% to 17.6%, but the adsorption capacity per unit mass, calculated based on the PVA dosage, increased from 2970 Bq / g to 5610 Bq / g. The results indicate that, under the same conditions, the mass ratio of the hydrogen-functionalized adsorbent material to the tritium-containing wastewater has a significant impact on the adsorption capacity per unit mass; adding an appropriate amount of PVA is beneficial for significantly increasing the tritium adsorption capacity per unit mass and reducing the solid waste content.

[0057] Compared with Comparative Example 4, the tritium removal rate of tritium-containing water in Example 4 increased from 4.8% to 8.6%, and the adsorption capacity per unit mass calculated based on PVA dosage increased from 3100 Bq / g to 5300 Bq / g. The results indicate that, within a certain range, the mass ratio of hydrogen-functionalized adsorbent material to tritium-containing wastewater has a significant impact on the tritium removal effect. When the dosage is too low, there are insufficient effective exchange sites in the system, which is not conducive to the enrichment and separation of tritium. The mass ratio used in Example 4 can balance material dosage and tritium removal effect.

[0058] Compared with Comparative Example 5, the tritium removal rate in Example 5 decreased from 35.1% to 33.4%, while the adsorption capacity per unit mass, calculated based on the amount of sulfonic acid resin added, significantly increased from 241 Bq / g to 465 Bq / g. The results indicate that, under the same conditions, the mass ratio of sulfonic acid-based adsorbent material to tritium-containing wastewater has a significant impact on the tritium adsorption capacity per unit mass; when the resin dosage is within an appropriate range, it is beneficial to significantly increase the tritium adsorption capacity per unit mass and reduce the solid waste content.

[0059] Compared with Comparative Example 6, the tritium removal rate in Example 6 increased from 8.2% to 21.8%, and the adsorption capacity per unit mass, calculated based on the amount of sulfonic acid resin added, increased from 576 Bq / g to 798 Bq / g. The results indicate that the mass ratio of sulfonic acid-based adsorbent material to tritium-containing wastewater needs to be controlled within a suitable range. When the resin dosage is insufficient, the overall enrichment capacity of the system decreases, while the mass ratio used in Example 6 is more conducive to balancing treatment capacity and adsorption performance per unit mass.

[0060] Compared with Comparative Example 7, the tritium removal rate in Example 7 increased from 7.4% to 18.9%, and the adsorption capacity per unit mass, calculated based on the PVA dosage, increased from 4700 Bq / g to 12200 Bq / g. The results indicate that under ultraviolet (UV) irradiation, UV intensity has a significant impact on tritium separation efficiency; when the UV intensity reaches the level set in Example 7, it is more conducive to enhancing the generation of active groups on the surface of the adsorbent material and in the interfacial water, thereby promoting hydrogen / tritium isotope exchange and improving tritium removal efficiency.

[0061] Compared with Comparative Example 8, the tritium removal rate in Example 8 increased from 6.3% to 21.6%, and the adsorption capacity per unit mass, calculated based on the PVA dosage, increased from 4000 Bq / g to 13900 Bq / g. The results indicate that, under the same conditions, appropriately extending the UV irradiation time is beneficial to increasing the extent of the hydrogen / tritium isotope exchange reaction in the system, thereby further enhancing the enrichment and separation of tritium; while insufficient irradiation time makes it difficult for the system to fully utilize the UV-promoting effect.

[0062] As can be seen from the above embodiments, the ultraviolet light irradiation-promoted tritium separation method and device proposed in this invention can significantly improve the tritium removal rate and adsorption capacity under normal temperature and pressure and simple structure conditions, taking into account both environmental emission reduction and tritium resource utilization needs, and has good prospects for engineering scale-up and application.

[0063] Compared with Example 1, under the same ultraviolet irradiation conditions, the tritium activity in the tritium-containing water of Comparative Example 9 did not change significantly due to the absence of adsorbent material in the system, and the apparent tritium removal rate was 0%. The results indicate that ultraviolet irradiation alone is insufficient to effectively separate tritium from tritium-containing water. The tritium separation effect of this invention mainly stems from the synergistic effect of ultraviolet irradiation and the adsorbent material.

[0064] This invention has been described through the specific embodiments described above. Those skilled in the art should understand that various modifications and equivalent substitutions can be made to this invention without departing from its scope. Parts not described in detail in this specification are well-known to those skilled in the art. Furthermore, various modifications can be made to this invention for specific situations or circumstances without departing from its scope. Therefore, this invention is not limited to the specific embodiments disclosed, but should include all embodiments falling within the scope of the claims.

Claims

1. A method for separating tritium from tritium-containing wastewater, characterized in that, The separation method is an ultraviolet light irradiation-promoted separation method, which includes the following steps: Step 1): The tritium-containing wastewater to be treated is introduced into the reaction container of the reactor system and comes into contact with the adsorbent material in the reaction container. The reaction is carried out at 20~40℃ for 0.5~4h to form a liquid-solid two-phase contact system. The mass of the tritium-containing wastewater added is 2 to 30 times the mass of the adsorbent material in the reaction container. The adsorbent material is an adsorbent material containing hydrogen-containing functional groups that can participate in hydrogen / tritium isotope exchange and / or an adsorbent material containing sulfonic acid groups. Step 2): Turn on the ultraviolet light source of the reactor system and emit ultraviolet light with a wavelength of 200-300 nm; the ultraviolet light irradiates the liquid-solid two-phase contact system for 12-72 h; after irradiation, tritium is enriched in the adsorbent material. Step 3): After irradiation, the liquid-solid two-phase contact system is subjected to solid-liquid separation to obtain low-concentration tritium-treated water and tritium-rich adsorbent material; Step 4): The tritium-rich adsorbent material is desorbed or calcined to recover tritium and obtain regenerated adsorbent material. The regenerated adsorbent material is used for recycling in Step 1); the low-concentration tritium-treated water is discharged in compliance with standards, reused, or subjected to deep tritium removal treatment.

2. The method for separating tritium from tritium-containing wastewater according to claim 1, characterized in that, The center wavelength of the ultraviolet light source is 100–400 nm.

3. The method for separating tritium from tritium-containing wastewater according to claim 1, characterized in that, The tritium activity concentration of the tritium-containing wastewater is greater than or equal to 0.01 MBq / L.

4. The method for separating tritium from tritium-containing wastewater according to claim 1, characterized in that, In step 1), the adsorbent is a hydrogen-functionalized adsorbent, which is a hydroxyl-containing hydrophilic polymer, and the structure of the hydroxyl-containing hydrophilic polymer contains at least one of the functional groups -OH, -CH2OH or -CH(OH)-. In step 1), the mass of the tritium-containing wastewater added is 2 to 30 times the mass of the hydrogen-containing functional group adsorbent material in the reaction container.

5. The method for separating tritium from tritium-containing wastewater according to claim 4, characterized in that, The hydroxyl-containing hydrophilic polymer material is polyvinyl alcohol.

6. The method for separating tritium from tritium-containing wastewater according to claim 1, characterized in that, In step 1), the adsorbent is a sulfonic acid-based adsorbent, which is an ion exchange resin containing sulfonic acid groups. The ion exchange resin is at least one of a sulfonic acid-type strong acid cation exchange resin or a modified product of a sulfonic acid-type strong acid cation exchange resin. In step 1), the mass of the tritium-containing wastewater added is 2 to 10 times the mass of the sulfonic acid-based adsorbent material added to the reaction container.

7. The method for separating tritium from tritium-containing wastewater according to claim 1, characterized in that, The liquid-solid two-phase contact system is either an intermittent stirring system or a continuous flow fixed bed system; In the intermittent stirring system, mechanical stirring or gas bubbling is used to maintain sufficient solid-liquid contact. The solid-liquid separation method described in step 3) is centrifugal separation or vacuum filtration separation.

8. A reactor system for a method of separating tritium from tritium-containing wastewater, characterized in that, The reactor system includes: a reaction container, an ultraviolet light source, a stirring unit, a circulation unit, an outlet pipe, and an inlet pipe; the ultraviolet light source is located outside the reaction container, the outlet pipe is connected to the treated water outlet of the reaction container, and the inlet pipe is connected to the wastewater inlet of the reaction container; The stirring unit is disposed inside the reaction container, and the circulation unit is connected to the reaction container; The inner cavity of the reaction container can hold tritium-containing wastewater and adsorption material, and the wall material of the reaction container is one or more of quartz, borosilicate glass or fluoropolymer. The reactor system is used for the method of separating tritium from tritium-containing wastewater as described in any one of claims 1 to 7.

9. The reactor system according to claim 8, characterized in that, The circulation unit of the reactor includes a circulation pump, a circulation guide pipe connected to the reaction container, a liquid distributor located at the inlet end of the reaction container, and a filter component located at the outlet end of the reaction container; the circulation pump drives the tritium-containing wastewater in the reaction container to flow out from the bottom of the reaction container and return to the upper part of the reaction container through the circulation guide pipe.

10. An application of a method for separating tritium from tritium-containing wastewater, characterized in that, The method for separating tritium from tritium-containing wastewater is the method for separating tritium from tritium-containing wastewater as described in any one of claims 1 to 7. The separation method is applied to the reduction of tritium-containing wastewater or the recovery of tritium resources generated by nuclear power plants, research reactors, isotope production or nuclear facilities.

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