Radioactive waste liquid treatment membrane and radioactive waste liquid treatment system

Abstract

The application discloses a radioactive waste liquid treatment membrane and a radioactive waste liquid treatment system. The radioactive waste liquid treatment membrane comprises an adsorption layer and a filter layer which are combined from top to bottom. The adsorption layer comprises a silicon-based porous body. The silicon-based porous body comprises a porous carrier. An organic polymer is combined on the porous carrier, and a functional group is grafted. The porous carrier is silicon dioxide. The functional group comprises at least one of a carboxyl group, a sulfonic acid group, an amino group and a quaternary ammonium group. The filter layer is a fiber material. The radioactive waste liquid treatment system comprises a raw water tank, a conveying pump and a membrane filter condensation device which are connected in sequence. The membrane filter condensation device is filled with the radioactive waste liquid treatment membrane. The radioactive waste liquid enters the raw water tank for storage, is conveyed to the membrane filter condensation device for filtration treatment by the conveying pump, and is then discharged from the radioactive waste liquid treatment system. The radioactive waste liquid treatment membrane and the radioactive waste liquid treatment system can effectively purify and filter the radioactive waste liquid.

Description

Technical Field

[0001] This invention relates to the field of radioactive waste treatment technology, and in particular to a radioactive waste treatment membrane and a radioactive waste treatment system. Background Technology

[0002] Currently, my country's operating and under-construction pressurized water reactor nuclear power plants mainly employ two processes for treating radioactive waste liquid: The first is the evaporation concentration process, which is applicable to a wide range of water qualities and can treat waste liquids with high salinity and complex composition. Heating causes a phase change in the waste liquid, leaving pollutants in the concentrate, and the condensate is discharged in compliance with standards. However, this process involves large equipment, numerous components, complex operation and maintenance, and high energy consumption. It also requires supporting solidification or drying devices for the evaporation concentrate, resulting in a large amount of secondary waste. The second process is a membrane-based combined process (such as activated carbon adsorption + ion exchange + reverse osmosis). This process uses smaller equipment, is easier to operate and maintain, and is suitable for low-salinity waste liquids, effectively removing ionic radionuclides. However, it has strict water quality requirements and cannot stably treat waste liquids with high salinity, organic matter, and complex chemical composition, thus limiting its treatment effectiveness.

[0003] In recent years, emerging technologies such as electrodeionization (EDI) combined membrane technology have also been researched and applied in the field of radioactive waste treatment. However, the technical route usually involves the series connection of multiple treatment units and the return of concentrated liquid, and the process flow is still relatively complex. The equipment footprint and operation and maintenance costs need to be further optimized. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a radioactive waste liquid treatment membrane and a radioactive waste liquid treatment system.

[0005] The technical solution adopted by the present invention to solve its technical problem is: a radioactive waste liquid treatment membrane, comprising an adsorption layer and a filter layer composited from top to bottom, wherein the adsorption layer comprises a silicon-based porous body, the silicon-based porous body comprises a porous carrier, and the porous carrier is combined with an organic polymer and grafted with functional groups. The porous carrier is silica; the functionalized groups include at least one of carboxyl, sulfonic acid, amino, and quaternary ammonium groups; the filter layer is a fibrous material.

[0006] Preferably, the fiber material includes at least one of polypropylene, polyethylene, polytetrafluoroethylene, polyvinylidene fluoride, and glass fiber.

[0007] Preferably, the organic polymer includes at least one of polydopamine, polystyrene, polyacrylic acid, polyethyleneimine, and polyvinyl alcohol.

[0008] Preferably, a selective extractant and / or an inorganic salt adsorbent is uniformly loaded within the porous support; The selective extractant is a crown ether and its derivatives or calixarene; or / and, the inorganic salt adsorbent is copper ferrocyanide, cobalt ferrocyanide, layered double hydroxide or zirconium phosphate.

[0009] Preferably, the porous carrier has a pore size of 100–900 nm; or / and, the radioactive waste treatment membrane is multi-layered and folded; or / and, the radioactive waste treatment membrane is wrinkled.

[0010] The present invention also proposes a radioactive waste liquid treatment system, comprising a raw water tank, a transfer pump and a membrane filtration coagulation device connected in sequence, wherein the membrane filtration coagulation device is filled with the aforementioned radioactive waste liquid treatment membrane. The radioactive waste liquid is stored in a raw water tank, then transported by a transfer pump to a membrane filtration and condensation unit for filtration treatment, and finally discharged from the radioactive waste liquid treatment system.

[0011] Preferably, the radioactive waste liquid treatment system further includes a delivery pipeline connected between the outlet of the raw water tank and the inlet of the membrane filtration condensation device; a delivery pump is installed on the delivery pipeline.

[0012] Preferably, the radioactive waste liquid treatment system further includes a pretreatment device, which is located on the delivery pipeline between the outlet of the raw water tank and the inlet of the delivery pump.

[0013] Preferably, the radioactive waste liquid treatment system further includes a discharge pipeline, the inlet end of which is connected to the outlet of the membrane filtration condensation device, and a monitoring device and a discharge valve are sequentially installed on the discharge pipeline; After being treated by a membrane filtration and condensation device, the radioactive waste liquid is discharged from the radioactive waste liquid treatment system through a discharge pipeline.

[0014] Preferably, the radioactive waste treatment system further includes a return pipeline connected between the outlet of the monitoring device and the inlet of the delivery pump, and a return valve is provided on the return pipeline.

[0015] The beneficial effects of this invention are: The radioactive waste liquid treatment membrane of the present invention includes an adsorption layer and a filter layer. The porous carrier silica in the adsorption layer adsorbs and retains macromolecular organic matter in the radioactive waste liquid, and the functional groups grafted on the porous carrier capture ionic radionuclides. The fiber material of the filter layer retains radioactive particulate matter, thereby achieving effective purification and filtration of radioactive waste liquid.

[0016] The radioactive waste liquid treatment system of the present invention has strong adaptability and can treat radioactive waste liquid with high salt content, organic matter, and complex composition. The system has a simple structure, significant waste liquid treatment effect, and high radionuclide removal rate, so that the effluent meets the discharge requirements. The overall operating cost of the radioactive waste liquid treatment system is low, the system energy consumption is low, the system operation and maintenance is simple, and the amount of secondary waste generated is small. Attached Figure Description

[0017] The present invention will be further described below with reference to the accompanying drawings and embodiments. In the accompanying drawings: Figure 1 These are schematic diagrams of radioactive waste liquid treatment systems in some embodiments of the present invention; The numbers in the attached diagram represent the following: 1. Raw water tank; 2. Pretreatment device; 3. Transfer pump; 4. Membrane filtration and condensation device; 41. Radioactive waste liquid treatment membrane; 5. Monitoring device; 6. Discharge valve; 7. Return valve; 81. Transfer pipeline; 82. Discharge pipeline; 83. Return pipeline. Detailed Implementation

[0018] To provide a clearer understanding of the technical features, objectives, and effects of the present invention, specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings. In the following description, it should be understood that the orientations or positional relationships indicated by terms such as "front," "rear," "upper," "lower," "left," "right," "longitudinal," "horizontal," "vertical," "horizontal," "top," "bottom," "inner," "outer," "head," and "tail" are based on the orientations or positional relationships shown in the accompanying drawings, and are constructed and operated in a specific orientation. They are only for the convenience of describing the technical solution and do not indicate that the device or element referred to must have a specific orientation; therefore, they should not be construed as limitations on the present invention.

[0019] It should also be noted that for experimental procedures or conditions not specifically described in this invention, the procedures or conditions can be performed according to conventional experimental procedures described in the literature in this field. Reagents or instruments whose manufacturers are not specified are all commercially available conventional reagent products.

[0020] This invention proposes a radioactive waste liquid treatment membrane, comprising an adsorption layer and a filter layer stacked from top to bottom. The adsorption layer includes a silicon-based porous body, which in turn includes a porous carrier. An organic polymer is bonded to the porous carrier and functionalized groups are grafted onto it. When radioactive waste liquid passes through the radioactive waste liquid treatment membrane, the adsorption layer and filter layer remove radionuclides from the waste liquid.

[0021] In this system, the porous carrier in the silicon-based porous body is silicon dioxide, which adsorbs and retains radionuclides in the radioactive waste liquid. In some embodiments, the pore size of the porous carrier is 100–900 nm, specifically 100 nm, 300 nm, 600 nm, 900 nm, etc.

[0022] In some embodiments, the porous support in the silicon-based porous body can be prepared using the sol-gel template method, and the specific preparation method includes the following steps: S1. Sol-gel and template assembly: The silicon source is hydrolyzed and condensed under acidic or alkaline catalytic conditions, and then a soft template agent is introduced for self-assembly. The silicon source can be tetraethyl orthosilicate (TEOS), and the soft template agent can be hexadecyltrimethylammonium bromide (CTAB), triblock copolymer P123, or triblock copolymer F127.

[0023] S2. Aging and Drying: Let it stand for aging, and then dry it.

[0024] S3. Template Removal: The soft template agent is removed by high-temperature calcination or chemical solvent etching, leaving open and interconnected silica channels.

[0025] Understandably, the preparation method of porous supports can refer to existing technologies, and the specific process parameters can be selected according to the actual process conditions, without being specifically limited here.

[0026] Organic polymers include at least one of polydopamine, polystyrene, polyacrylic acid, polyethyleneimine, and polyvinyl alcohol. Polydopamine can form a robust polydopamine layer on silica surfaces, and its abundant phenolic hydroxyl and amino groups readily facilitate the grafting of functional molecules (such as crown ethers), thereby improving the material's antifouling properties. Polystyrene possesses anion exchange capacity. Polyacrylic acid and polyvinyl alcohol exhibit good film-forming properties and are rich in hydroxyl and carboxyl groups, facilitating subsequent secondary grafting modifications. Furthermore, the carboxyl groups of polyvinyl alcohol are effective against cations such as UO2. 2+ (Uranyl ion), Co 2+ Cobalt ions possess excellent complexing ability and strong pH responsiveness, which is beneficial for regulating membrane flux. Polyethyleneimine is a high-density amino carrier, rich in amino groups, which can serve as adsorption sites for heavy metal ions and is also conducive to further cross-linking or grafting crown ethers or calixarenes.

[0027] In some embodiments, the method of binding an organic polymer on a porous support includes the following steps: S1. Interface Modification Preparation: The porous support is aminated using a silane coupling agent to provide reactive sites. Since the surface of pure silica is rich in hydrophilic silanol groups, direct grafting of polymers may cause compatibility issues. Therefore, amination is performed first using a silane coupling agent, such as 3-aminopropyltriethoxysilane (APTES).

[0028] S2, In-situ polymerization or impregnation coating: The monomer solution of the polymer is injected into the porous carrier of step S1 to initiate an in-situ polymerization reaction, so that an organic polymer is formed in the porous carrier; or a pre-synthesized organic polymer solution is filled into the porous carrier of step S1 by vacuum impregnation, so that the organic polymer is firmly attached to the framework and inner surface of the porous carrier.

[0029] Understandably, the method of combining organic polymers on porous supports can refer to existing technologies, and the specific process parameters can be selected according to the actual process conditions, without being specifically limited here.

[0030] Functionalized groups include at least one of carboxyl, sulfonic acid, amino, and quaternary ammonium groups. Among these, anionic groups such as carboxyl and sulfonic acid groups impart a negative charge and high charge density to the material, significantly improving its selective permeability to cations such as sodium ions, making it suitable for cation exchange. Cationic groups such as amino and quaternary ammonium groups impart a positive charge to the material, enabling the adsorption of anions.

[0031] In some embodiments, the method of grafting functionalized groups onto a porous support includes the following steps: S1. Introducing the initiation site: Modifying the porous support surface with a silane coupling agent containing an initiator group. The silane coupling agent containing the initiator group can be (3-bromopropyl)trimethoxysilane or BTPA.

[0032] S2. In-situ polymerization: Under the action of an initiator, monomers with functionalized groups are polymerized on the surface of a porous support, so that the functionalized groups are grafted onto the porous support.

[0033] Understandably, the method of grafting functional groups onto porous supports can refer to existing technologies, and the specific process parameters can be selected according to the actual process conditions, without being specifically limited here.

[0034] In some embodiments, a selective extractant and / or an inorganic salt adsorbent are uniformly loaded within the porous support. The selective extractant is a crown ether or its derivatives, or a calixarene. Crown ethers and their derivatives exhibit extremely high complexation selectivity for alkali metal and alkaline earth metal ions and are widely used for the extraction and separation of radionuclides or specific metal ions. Calixarenes can be used to identify and capture specific small organic molecules or heavy metal ions. The inorganic salt adsorbent is copper ferrocyanide, cobalt ferrocyanide, layered double hydroxides (LDHs), or zirconium phosphate. Prussian blue analogues such as copper ferrocyanide and cobalt ferrocyanide possess excellent ion exchange and fixation capabilities for radioactive metal ions such as cesium and thallium ions. Layered double hydroxides can capture anionic nuclides, and zirconium phosphate can capture strontium and cesium ions.

[0035] In some embodiments, the method of loading a selective extractant or an inorganic salt adsorbent into the pores of a porous support includes the following steps: S1. Impregnation: The porous carrier is immersed in a solution containing functional agents (selective extractants or inorganic salt adsorbents). Through capillary action and concentration difference, the functional agent molecules in the solution diffuse into the pores of the porous carrier.

[0036] S2. Solution Removal: Evaporation and drying are performed to remove the solution, leaving the functional agent within the porous support. Evaporation and drying can be performed via rotary evaporation or vacuum drying.

[0037] S3. Immobilization: For macromolecular or solid inorganic salt adsorbents, physical adsorption and immobilization are achieved by utilizing the pores of the porous carrier itself; for selective extractants, the inner wall of the pores of the porous carrier is first modified with a silane coupling agent, and then the selective extractant is bonded through a chemical reaction; or, after loading the functional agent, the monomer is introduced to polymerize in the pores of the porous carrier, and the functional agent is embedded in the polymer.

[0038] Understandably, the method of loading selective extractants or inorganic salt adsorbents into the pores of a porous carrier can refer to existing technologies, and the specific process parameters can be selected according to the actual process conditions, without being specifically limited here.

[0039] Preferably, the porous carrier has organic matter and functionalized groups grafted onto the inner surface of the pores and the surface of the framework, while simultaneously loading selective extractants and inorganic salt adsorbents.

[0040] The filter layer is made of fibrous material, which is used to trap radioactive particles in radioactive waste liquid while allowing water and non-radioactive ions to pass through. In some embodiments, the fibrous material includes at least one of polypropylene, polyethylene, polytetrafluoroethylene, polyvinylidene fluoride, and glass fiber.

[0041] In some embodiments, the method of composited with a filter layer at the bottom of the adsorption layer includes physical composite methods and chemical composite methods. The physical composite method can be a hot-pressing method, specifically, stacking the fibrous material of the filter layer with the adsorption layer and hot-pressing them together under appropriate temperature and pressure. Temperature control is necessary to prevent the collapse of the pore structure of the adsorption layer. The chemical composite method can be an impregnation bonding method, specifically, impregnating the area where the adsorption layer and the filter layer are in contact with each other using a dilute solution of a polymer adhesive, followed by drying and curing. The adhesive can be PVAc or waterborne polyurethane.

[0042] Preferably, the radioactive waste liquid treatment membrane is multi-layered and folded, or the radioactive waste liquid treatment membrane is wrinkled; or the radioactive waste liquid treatment membrane is multi-layered and folded, which further increases the effective filtration area per unit volume, improves the specific surface area and dirt holding capacity, thereby improving the filtration and treatment efficiency of radioactive waste liquid.

[0043] The radioactive waste liquid treatment membrane of the present invention includes an adsorption layer and a filter layer. The porous carrier silica in the adsorption layer adsorbs and retains macromolecular organic matter in the radioactive waste liquid, and the functional groups grafted on the porous carrier capture ionic radionuclides. The fiber material of the filter layer retains radioactive particulate matter, thereby achieving effective purification and filtration of radioactive waste liquid.

[0044] The following is an illustration through specific examples: Example 1 The radioactive waste treatment membrane of this embodiment includes an adsorption layer and a filter layer composited from top to bottom. The adsorption layer includes a silicon-based porous body, which includes a porous carrier. An organic polymer is bonded to the porous carrier, and functionalized groups are grafted onto it. The porous carrier is made of silica with a pore size of 500 nm. The organic polymer includes polydopamine, and the functionalized groups include carboxyl and sulfonic acid groups. A selective extractant and an inorganic salt adsorbent are uniformly loaded within the porous carrier. The selective extractant is a crown ether (dicyclohexyl-18-crown-6), and the inorganic salt adsorbents are copper ferrocyanide and cobalt ferrocyanide. The filter layer is made of fibrous material, including polypropylene and polyethylene. The radioactive waste treatment membrane is multi-layered and folded.

[0045] Example 2 The difference between this embodiment and Embodiment 1 is that the porous carrier in the radioactive waste treatment membrane of this embodiment has a pore size of 300 nm. The organic polymers include polyacrylic acid and polyvinyl alcohol, and the functionalized groups include amino and quaternary ammonium groups. The selective extractant is a crown ether (dibenzo-18-crown-6), and the inorganic salt adsorbent is a layered double hydroxide. The fibrous materials include polytetrafluoroethylene and polyvinylidene fluoride.

[0046] Example 3 The difference between this embodiment and Embodiment 1 is that the porous carrier in the radioactive waste treatment membrane of this embodiment has a pore size of 800 nm. The organic polymer includes polystyrene, and the functionalized groups include sulfonic acid groups. The selective extractant is 1,3-diisopropoxycalixarene crown ether-6, and the inorganic salt adsorbent is zirconium phosphate. The fiber material includes glass fiber.

[0047] like Figure 1 As shown, in some embodiments of the present invention, a radioactive waste liquid treatment system includes a raw water tank 1, a transfer pump 3, and a membrane filtration and condensation device 4 connected in sequence. The membrane filtration and condensation device 4 is filled with the aforementioned radioactive waste liquid treatment membrane 41. The radioactive waste liquid is stored in the raw water tank 1, then transported by the transfer pump 3 to the membrane filtration and condensation device 4 for filtration treatment, and subsequently discharged from the radioactive waste liquid treatment system.

[0048] The raw water tank 1 is connected to the upstream pipeline to receive radioactive waste liquid containing complex components, and has temporary storage and homogenization functions. The membrane filtration and condensation unit 4 is the core treatment unit, filled with the aforementioned radioactive waste liquid treatment membrane 41. It operates using a dead-end filtration method, with no concentrated water circulation during operation. The radioactive waste liquid treatment membrane 41 is multi-layered and wrinkled, possessing multiple functions including physical adsorption, ion exchange, size retention, and chemical selective coordination. Specifically, the radioactive waste liquid treatment membrane 41 achieves physical adsorption and size retention through a porous carrier, and ion exchange and chemical selective coordination through grafted functional groups.

[0049] The membrane filtration condensation device 4 is deeply integrated with the radioactive waste treatment membrane 41. The filling volume of the radioactive waste treatment membrane 41 (membrane material) can be calculated based on the volume of wastewater treated per cycle, the ion concentration in the wastewater, and the organic matter content. The effective volume of the filter container of the membrane filtration condensation device 4 is matched with the filling volume of the membrane material. A suitable aspect ratio is calculated considering flow rate, pressure drop, and the mechanical strength of the membrane material. The membrane material is replaced after each wastewater treatment cycle. When the volume of radioactive wastewater is relatively small, the advantages of wastewater treatment are obvious.

[0050] The radioactive waste treatment membrane 41 is compatible with the dead-end filtration method of the membrane filtration condensation device 4, eliminating the need for backwashing and chemical rinsing. The filter container of the membrane filtration condensation device 4 is filled with membrane material, which serves as the adsorption and retention medium. When waste liquid is pumped onto the membrane surface, all liquid must pass through the membrane pores, and contaminants are retained and directly accumulate on the membrane surface, thus adapting to the dead-end filtration method. In contrast, traditional filter containers are filled with ion exchange resins, activated carbon, etc., which are granular materials unsuitable for dead-end filtration.

[0051] Existing membrane processes for the deep treatment of radioactive waste liquid, such as ultrafiltration, nanofiltration, and reverse osmosis, all involve the circulation of concentrated water. The radioactive waste liquid treatment system of this invention can achieve deep treatment of waste liquid, but does not involve the circulation of concentrated water.

[0052] Furthermore, the radioactive waste treatment system also includes a delivery pipeline 81, which connects the outlet of the raw water tank 1 to the inlet of the membrane filtration condensation device 4. A delivery pump 3 is installed on the delivery pipeline 81 to provide power for the delivery of the radioactive waste. The delivery pump 3 can be selected as a centrifugal pump or a metering pump depending on the properties of the radioactive waste.

[0053] In some embodiments, the radioactive waste treatment system further includes a pretreatment device 2, which is located on the delivery pipeline 81 between the outlet of the raw water tank 1 and the inlet of the delivery pump 3. Before being delivered to the membrane filtration and condensation device 4, the radioactive waste in the raw water tank 1 is first delivered to the pretreatment device 2 for filtration pretreatment, thus reducing the filtration load on the radioactive waste treatment membrane 41. The pretreatment device 2 can employ physical, chemical, or biological pretreatment methods. For example, if physical pretreatment is used, the pretreatment device 2 can be equipped with multi-stage filtration devices to remove large particles from the radioactive waste; if chemical pretreatment is used, the pretreatment device 2 can be equipped with a reaction tank according to the composition of the radioactive waste, removing waste components through coagulation and oxidation reactions.

[0054] Furthermore, the radioactive waste treatment system also includes a discharge pipeline 82, the inlet of which is connected to the outlet of the membrane filtration condensation device 4. A monitoring device 5 and a discharge valve 6 are sequentially installed on the discharge pipeline 82 along the direction of water flow. After being treated by the membrane filtration condensation device 4, the radioactive waste is discharged from the radioactive waste treatment system through the discharge pipeline 82.

[0055] The monitoring device 5 is located at the outlet of the membrane filtration condensation device 4 and is used to monitor the water quality of the effluent (i.e. the treated waste liquid) of the membrane filtration condensation device 4. If the water quality of the effluent meets the standards and discharge standards, the discharge valve 6 is opened and the effluent is discharged from the radioactive waste liquid treatment system through the discharge pipeline 82.

[0056] In some embodiments, the radioactive waste treatment system further includes a return pipeline 83, which is connected between the outlet of the monitoring device 5 and the inlet of the transfer pump 3. The return pipeline 83 is equipped with a return valve 7 and a return pump (not shown). If the monitoring device 5 detects that the effluent quality of the membrane filtration condensation device 4 does not meet the standards, it closes the discharge valve 6, opens the return valve 7, and starts the return pump. The effluent returns to the transfer pipeline 81 through the return pipeline 83 and is pressurized by the transfer pump 3 and transported to the membrane filtration condensation device 4 for further filtration until the effluent quality meets the standards and is discharged, thereby dynamically ensuring that the final effluent treatment meets the standards.

[0057] The radioactive waste liquid treatment system of this invention is highly adaptable and can treat radioactive waste liquids with high salt content, organic matter, and complex composition. Ionic impurities in the waste liquid can be captured by functionalized groups grafted onto a porous carrier, and large-molecule organic matter can be adsorbed by the large-pore porous carrier, filling the technological gap between existing evaporation processes and traditional membrane combination processes. The radioactive waste liquid treatment system has a simple structure and process flow, and can operate fully automatically. The waste liquid treatment effect is significant, with a radionuclide removal rate of over 99%, stable treatment effect, and effluent meeting discharge requirements. The overall cost is low, the system occupies a small area, has low energy consumption (reducing energy consumption by approximately 80% compared to evaporation processes), is easy to operate and maintain, and generates little secondary waste. The radioactive waste liquid treatment system of this invention can serve as an alternative to existing waste liquid treatment processes or a deep purification treatment solution.

[0058] The present invention also proposes a method for treating radioactive waste liquid, which is applied to the above-mentioned radioactive waste liquid treatment system. The treatment method includes: storing the radioactive waste liquid in the raw water tank 1, pressurizing and transporting the radioactive waste liquid to the membrane filtration and condensation device 4 for filtration treatment by the transfer pump 3, and then discharging the treated waste liquid from the radioactive waste liquid treatment system.

[0059] When radioactive waste liquid is filtered in the membrane filtration and condensation device 4, the radioactive waste liquid passes through the adsorption layer and the filter layer of the radioactive waste liquid treatment membrane 41 in sequence. The radionuclides are fixed in the radioactive waste liquid treatment membrane 41 through adsorption, ion exchange and physical interception. Water and non-radioactive ions pass through the radioactive waste liquid treatment membrane 41 and are discharged from the membrane filtration and condensation device 4.

[0060] Furthermore, in the radioactive waste liquid treatment method, the radioactive waste liquid is discharged from the membrane filtration and condensation device 4 after filtration treatment, and the effluent water quality is monitored by the monitoring device 5. If the water quality meets the standards, the discharge valve 6 is opened to discharge it. If the water quality does not meet the standards, the discharge valve 6 is closed, the return valve 7 is opened, the effluent enters the return pipeline 83 and flows back into the delivery pipeline 81 until the effluent water quality meets the standards and is discharged; or, if the water quality does not meet the standards, such as the radioactivity level exceeding the standard, the radioactive waste liquid treatment membrane 41 in the membrane filtration and condensation device 4 is replaced as a whole, and the effluent water quality meets the standards before being discharged.

[0061] Compared with existing evaporation processes, the radioactive waste liquid treatment method of the present invention has a smaller system footprint, lower energy consumption (energy consumption reduced by more than 80%), and less secondary waste. Compared with traditional membrane combination processes, it has stronger water quality adaptability and simpler operation and maintenance. Compared with EDI multi-unit combined membrane processes, the system structure is simpler and does not require concentrated liquid circulation. It can be directly used as a radioactive waste liquid treatment method for existing nuclear power plants and has good engineering application and promotion value.

[0062] The radioactive waste liquid treatment method of the present invention is applicable to the treatment of radioactive waste liquid with high salt content (preferably 5-30 g / L), containing organic matter, and with complex chemical composition. It is suitable for both alternative scenarios where evaporation processes are limited by space or cost and for deep purification scenarios where traditional membrane combination processes cannot treat complex radioactive waste liquids.

[0063] Understandably, the above-mentioned technical features can be used in any combination without restriction.

[0064] The above embodiments only illustrate preferred embodiments of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can freely combine the above technical features without departing from the concept of the present invention, and can also make several modifications and improvements, all of which fall within the protection scope of the present invention. Therefore, all equivalent transformations and modifications made with respect to the scope of the claims of the present invention should fall within the scope of the claims of the present invention.

Claims

1. A radioactive waste liquid treatment membrane, characterized in that, It includes an adsorption layer and a filter layer that are composited from top to bottom. The adsorption layer includes a silicon-based porous body, which includes a porous carrier. The porous carrier is bonded with an organic polymer and grafted with functional groups. The porous carrier is silicon dioxide; the functionalized groups include at least one of carboxyl, sulfonic acid, amino, and quaternary ammonium groups; the filter layer is a fibrous material.

2. The radioactive waste liquid treatment membrane according to claim 1, characterized in that, The fiber material includes at least one of polypropylene, polyethylene, polytetrafluoroethylene, polyvinylidene fluoride, and glass fiber.

3. The radioactive waste liquid treatment membrane according to claim 1, characterized in that, Organic polymers include at least one of polydopamine, polystyrene, polyacrylic acid, polyethyleneimine, and polyvinyl alcohol.

4. The radioactive waste liquid treatment membrane according to claim 1, characterized in that, The porous carrier is uniformly loaded with selective extractants and / or inorganic salt adsorbents; The selective extractant is a crown ether and its derivatives or a calixarene; or / and the inorganic salt adsorbent is copper ferrocyanide, cobalt ferrocyanide, layered double hydroxide or zirconium phosphate.

5. The radioactive waste treatment membrane according to any one of claims 1 to 4, characterized in that, The porous carrier has a pore size of 100–900 nm; or / and the radioactive waste treatment membrane is multi-layered and folded; or / and the radioactive waste treatment membrane is wrinkled.

6. A radioactive waste liquid treatment system, characterized in that, It includes a raw water tank (1), a transfer pump (3) and a membrane filtration condensation device (4) connected in sequence, wherein the membrane filtration condensation device (4) is filled with a radioactive waste liquid treatment membrane (41) as described in any one of claims 1 to 5; The radioactive waste liquid is stored in the raw water tank (1), and then transported to the membrane filtration condensation device (4) by the transfer pump (3) for filtration treatment, and then discharged from the radioactive waste liquid treatment system.

7. The radioactive waste liquid treatment system according to claim 6, characterized in that, The radioactive waste liquid treatment system also includes a delivery pipeline (81), which is connected between the outlet of the raw water tank (1) and the inlet of the membrane filtration condensation device (4); the delivery pump (3) is installed on the delivery pipeline (81).

8. The radioactive waste liquid treatment system according to claim 7, characterized in that, The radioactive waste liquid treatment system also includes a pretreatment device (2), which is located on the delivery pipeline (81) and between the outlet of the raw water tank (1) and the inlet of the delivery pump (3).

9. The radioactive waste liquid treatment system according to claim 6, characterized in that, The radioactive waste liquid treatment system also includes a discharge pipeline (82), the inlet end of which is connected to the outlet of the membrane filtration condensation device (4), and a monitoring device (5) and a discharge valve (6) are sequentially provided on the discharge pipeline (82); After being treated by the membrane filtration condensation device (4), the radioactive waste liquid is discharged from the radioactive waste liquid treatment system through the discharge pipeline (82).

10. The radioactive waste liquid treatment system according to claim 9, characterized in that, The radioactive waste liquid treatment system also includes a return pipeline (83), which is connected between the outlet of the monitoring device (5) and the inlet of the delivery pump (3), and a return valve (7) is provided on the return pipeline (83).

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