Radioactive wastewater treatment system

Abstract

The utility model discloses a radioactive wastewater treatment system which comprises a source storage water well, a nuclear sewage collection tank, a sedimentation tank, an evaporator, a solidification tank and a reverse osmosis membrane filter, the source storage water well is connected with the sedimentation tank, and a water pumping pipe of the sedimentation tank is provided with a channel type radioactive substance monitor and a first three-way electromagnetic valve; the first three-way electromagnetic valve is respectively connected with the reservoir and the reverse osmosis membrane filter through a first branch pipe and a second branch pipe, the reverse osmosis membrane filter is connected with the reservoir, and a sewage purification pipe of the reverse osmosis membrane filter and a sludge suction pipe of the sedimentation tank are connected with the solidification tank; a second three-way electromagnetic valve is arranged on the nuclear sewage collecting box and is respectively communicated with the settling pond and the evaporator through a fourth branch pipe and a fifth branch pipe, a sewage draining outlet of the evaporator is communicated with the curing pond through a sewage draining pipe, a steam outlet of the evaporator is connected with a condenser, and the condenser is connected with a water storage pond. According to the utility model, the treatment efficiency and the treatment effect are improved.

Description

Technical Field

[0001] This utility model relates to the field of wastewater treatment, and in particular to a radioactive wastewater treatment system. Background Technology

[0002] In the irradiation industry, radioactive sources need to be stored in source wells and isolated with water. When the water quality in the source wells changes, clean water needs to be replaced. In the irradiation industry, nuclear decontamination is also required for items or personnel contaminated by nuclear radiation. The water in the source wells and the water after nuclear decontamination have high radioactivity and need to be strictly treated before they can be discharged.

[0003] Currently, commercially available methods for treating radioactive wastewater include chemical precipitation, ion exchange, adsorption, evaporation concentration, and membrane separation. Generally, a single method is used, but each method has its own drawbacks. Chemical precipitation makes it difficult to precisely control the amount of flocculant used; excessive flocculant will pollute the water, while insufficient flocculant will prevent complete precipitation of radioactive nuclides, affecting treatment efficiency. Ion exchange is complex to operate and has a small exchange capacity; while it is highly effective for small amounts of radioactive wastewater, it has significant limitations. Adsorption methods are prone to saturation, losing their adsorption capacity. Evaporation concentration is energy-intensive when treating large volumes of radioactive wastewater. Membrane separation suffers from pollutants adhering to the membrane surface, leading to low separation efficiency and requiring frequent replacement or cleaning. Utility Model Content

[0004] The purpose of this invention is to provide a radioactive wastewater treatment system that can efficiently remove radioactive elements from radioactive wastewater.

[0005] To achieve the above objectives, the technical solution adopted by this utility model is: a radioactive wastewater treatment system, comprising: a source water well, a nuclear wastewater collection tank, a sedimentation tank, an evaporator, a solidification tank, and a reverse osmosis membrane filter. The source water well is connected to the sedimentation tank via an outlet pipe. A storage funnel, a pumping pipe, and a sludge suction pipe are installed on the sedimentation tank. Flocculant is stored in the storage funnel. A connection hole is provided on the pumping pipe, and a channel-type radioactive material monitor is sealed on the connection hole. A first three-way solenoid valve is installed at the outlet end of the pumping pipe, and a first branch pipe and a second... The system consists of branch pipes. The first branch pipe is connected to the water storage tank, the second branch pipe is connected to the reverse osmosis membrane filter, the reverse osmosis membrane filter is connected to the water storage tank via the third branch pipe, and the clean and dirty pipes of the reverse osmosis membrane filter and the sludge suction pipe of the sedimentation tank are all connected to the solidification tank. A second three-way solenoid valve is installed at the outlet of the nuclear wastewater collection tank. A fourth and fifth branch pipe are connected to the second three-way solenoid valve. The fourth branch pipe is connected to the sedimentation tank, the fifth branch pipe is connected to the evaporator, the evaporator's drain outlet is connected to the solidification tank via a drain pipe, the evaporator's steam outlet is connected to the condenser, and the condenser is connected to the water storage tank.

[0006] Furthermore, in the aforementioned radioactive wastewater treatment system, a first pipeline filter is installed on the pumping pipe located in front of the channel-type radioactive material monitor. The filtration accuracy of the first pipeline filter is between 0.1 and 5 μm.

[0007] Furthermore, in the aforementioned radioactive wastewater treatment system, a second pipeline filter is installed on the fifth branch pipe, and the filtration accuracy of the second pipeline filter is between 0.1 and 5 μm.

[0008] Furthermore, in the aforementioned radioactive wastewater treatment system, the evaporator is a thin-film evaporator.

[0009] Furthermore, in the aforementioned radioactive wastewater treatment system, the volume of the sedimentation tank is 1.3 to 1.5 times the volume of the source water well.

[0010] Furthermore, in the aforementioned radioactive wastewater treatment system, a support platform is fixed on the sedimentation tank, and two storage funnels are symmetrically arranged on the support platform. The discharge pipes of the storage funnels pass through the support platform and extend into the sedimentation tank. A rotating shaft is rotatably installed on the support platform, extending downward into the sedimentation tank and rotatably connected to the bottom wall of the sedimentation tank. Several stirring blades are evenly distributed on the rotating shaft. A drive mechanism capable of driving the rotating shaft is installed on the support platform. A water pumping pipe and a sludge suction pipe are respectively installed on both sides of the sedimentation tank.

[0011] Furthermore, in the aforementioned radioactive wastewater treatment system, the solidification tank includes: a ceramic melting furnace, with a ventilation hole and a feed inlet at the top of the ceramic melting furnace; an electromagnetic butterfly valve is flanged to the feed inlet; a mixing chamber is flanged to the electromagnetic butterfly valve; a stirring shaft is horizontally arranged in the mixing chamber; a spiral stirring blade is arranged on the stirring shaft; a drive mechanism capable of driving the stirring shaft to rotate is arranged on the mixing chamber; a first waste liquid inlet pipe, a second waste liquid inlet pipe, a third waste liquid inlet pipe, and a glass substrate inlet pipe are arranged at the top of the mixing chamber; the first waste liquid inlet pipe is connected to a sludge suction pipe; the second waste liquid inlet pipe is connected to a sewage discharge pipe; and the third waste liquid inlet pipe is connected to a clean sewage pipe.

[0012] The advantages of this invention are that it can overcome the various defects of the original single treatment method, improve the treatment efficiency and effect, and also select the appropriate treatment method according to the amount of radioactive wastewater. When it is necessary to replace radioactive wastewater in the source water well or when a large amount of radioactive wastewater is generated from nuclear decontamination, the large amount of radioactive wastewater can be discharged into a sedimentation tank for chemical precipitation with flocculants. Then, depending on whether the nuclear radiation level of the water discharged from the sedimentation tank meets the standards, it can be either directly discharged into a reservoir for use or treated secondaryly using a reverse osmosis membrane filter to meet the discharge standards. When using a sedimentation tank in conjunction with a reverse osmosis membrane filter for secondary treatment, the sedimentation tank can both precipitate radionuclides in the radioactive wastewater and filter impurities in the radioactive wastewater, preventing excessive impurities from damaging the reverse osmosis membrane in the reverse osmosis membrane filter. When the amount of radioactive wastewater generated from nuclear decontamination is small, a small amount of radioactive wastewater can be discharged into an evaporator for high-temperature evaporation, and then the water vapor can be condensed and discharged into a reservoir for use. The precipitates, impurities, and other waste generated during the treatment process can be discharged into a solidification tank and solidified with a glass substrate, which can effectively reduce the volume of waste, help reduce the space requirements for storage and subsequent treatment, and the solidified glass substrate has good chemical stability and durability, and can resist the corrosion of various chemical substances, thereby improving the isolation effect of radioactive materials. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the radioactive wastewater treatment system described in this utility model.

[0014] Figure 2 yes Figure 1 A top-view structural diagram of the intermediate sedimentation tank.

[0015] Figure 3 yes Figure 2 A cross-sectional structural diagram.

[0016] Figure 4 yes Figure 1 A top-view structural diagram of the intermediate curing tank.

[0017] Figure 5 yes Figure 4 A cross-sectional structural diagram. Detailed Implementation

[0018] The technical solution of this utility model will be further described below with reference to the accompanying drawings and preferred embodiments.

[0019] like Figures 1-5As shown, the radioactive wastewater treatment system of this utility model includes: a source water well 1, a nuclear wastewater collection tank 2, a sedimentation tank 3, an evaporator 4, a solidification tank 5, and a reverse osmosis membrane filter 6. The source water well 1 is connected to the sedimentation tank 3 through an outlet pipe 11. The volume of the sedimentation tank 3 is 1.3 to 1.5 times the volume of the source water well 1. In this way, when all the wastewater in the source water well 1 is discharged into the sedimentation tank 3, the wastewater will not overflow from the sedimentation tank 3, and the addition of a large amount of chemical flocculant will not cause wastewater overflow during the sedimentation reaction. A support platform 31 is fixed on the sedimentation tank. Two storage funnels 32 are symmetrically arranged on the support platform 31, storing flocculant. In this embodiment, the flocculant used is starch xanthate, which is insoluble in water and does not produce sulfides when chemically precipitating radioactive nuclides. Moreover, the radioactivity removal rate is >90%. The discharge pipe of the storage funnel 32 passes through the support platform 31 and extends into the sedimentation tank 3. A rotating shaft 33 is rotatably mounted on the support platform 31, extending downwards into the sedimentation tank 3. The shaft 33 is rotatably connected to the bottom wall of the sedimentation tank 3. Several stirring blades 34 are evenly distributed on the shaft 33. A drive mechanism capable of driving the shaft 33 to rotate is provided on the support platform 31. The drive mechanism is a common structure of a geared motor and a synchronous belt transmission assembly. A water pumping pipe 35 and a sludge suction pipe 36 are respectively provided on both sides of the sedimentation tank 3. A connection hole is opened on the water pumping pipe 35, and a channel-type radioactive material monitor 7 is sealed on the connection hole. A first pipeline filter is provided on the water pumping pipe 35 located in front of the channel-type radioactive material monitor 7. 351, the first pipeline filter 351 has a filtration accuracy between 0.1 and 5 μm. This filtration accuracy can filter out large particulate impurities such as silt in the water. A first three-way solenoid valve 352 is installed at the outlet end of the water pumping pipe 35. A first branch pipe 353 and a second branch pipe 354 are connected to the first three-way solenoid valve 352. The first branch pipe 353 is connected to the water storage tank 8, and the second branch pipe 354 is connected to the reverse osmosis membrane filter 6. The reverse osmosis membrane in the reverse osmosis membrane filter 6 has the highest filtration accuracy, ranging from 0.0001 to 0.Between 0.01μm, it can remove a variety of pollutants, including bacteria, viruses, heavy metal ions, and small molecule organic matter. Water filtered through reverse osmosis membranes generally meets national discharge standards. The reverse osmosis membrane filter 6 is connected to the water storage tank 8 via a third branch pipe 61. The clean and dirty pipe 62 in the reverse osmosis membrane filter 6 and the sludge suction pipe 36 in the sedimentation tank 3 are both connected to the solidification tank 5. A second three-way solenoid valve 21 is installed at the outlet of the nuclear wastewater collection tank 2. A fourth branch pipe 22 and a fifth branch pipe 23 are connected to the second three-way solenoid valve 21. The fourth branch pipe 22 is connected to the sedimentation tank 3. The fifth branch pipe 23 is connected to the evaporator 4, which is a thin-film evaporator. Due to its high heat transfer efficiency and rapid evaporation rate, the thin-film evaporator can effectively and quickly evaporate the water in radioactive wastewater, which is highly beneficial for reducing the volume of radioactive wastewater. Secondly, the thin-film evaporator can achieve vacuum operation, which helps to lower the boiling point of the radioactive wastewater and further accelerate the evaporation process. It is particularly suitable for treating radioactive wastewater with high boiling points and high viscosity. Furthermore, the short residence time of materials in the thin-film evaporator helps to reduce thermal damage to heat-sensitive radionuclides and maintain their stability. A second pipeline filter 24 is installed on the fifth branch pipe 23. The filtration accuracy of the second pipeline filter 24 also needs to be controlled between 0.1 and 5 μm. The drain outlet of the evaporator 4 is connected to the solidification tank 5 through the drain pipe 41. The steam outlet of the evaporator 5 is connected to the condenser 9, and the condenser 9 is connected to the water storage tank 8.

[0020] In this embodiment, each pipeline is equipped with a diaphragm pump, gear pump, or electromagnetic pump to extract radioactive waste liquid. This is a conventional technique and is therefore not shown in the figure.

[0021] In this embodiment, the solidification tank 5 includes: a ceramic melting furnace 51, with a ventilation hole 50 and a feed inlet on the top of the ceramic melting furnace 51. An electromagnetic butterfly valve 52 is flanged and connected to the feed inlet. A mixing chamber 53 is flanged and connected to the electromagnetic butterfly valve 52. A stirring shaft 54 ​​is horizontally arranged in the mixing chamber 53. A spiral stirring blade 541 is arranged on the stirring shaft 54. A drive mechanism capable of driving the stirring shaft 54 ​​to rotate is arranged on the mixing chamber 53. The drive mechanism is a common structure of a geared motor and a synchronous belt transmission assembly. A first waste liquid inlet pipe 531, a second waste liquid inlet pipe 532, a third waste liquid inlet pipe 533, and a glass substrate inlet pipe 534 are arranged on the top of the mixing chamber 53. The first waste liquid inlet pipe 531 is connected to the sludge suction pipe 36, the second waste liquid inlet pipe 532 is connected to the sewage discharge pipe 41, and the third waste liquid inlet pipe 533 is connected to the clean sewage pipe 62.

[0022] When it is necessary to replace the water in the source water well 1, the radioactive wastewater in the source water well 1 is sent into the sedimentation tank 3 through the outlet pipe 11. Then, the two storage funnels 32 are opened, and the starch xanthate in the storage funnels 32 falls into the sedimentation tank 3 and comes into contact with the radioactive wastewater. Then, the rotating shaft 33 drives the stirring blades 34 to stir, so that the starch xanthate and the radioactive wastewater come into full contact. The radionuclides in the radioactive wastewater combine with the starch xanthate to form precipitates. After thorough stirring, stirring is stopped, and the precipitates settle to the bottom wall of the sedimentation tank 3. Then, the radioactive wastewater in the sedimentation tank 3 is pumped out through the pumping pipe 35. The first pipeline filter 351 filters the precipitates and excess starch xanthate. The channel-type radioactive material monitor 7 can monitor the radiation level of the water in the pumping pipe 35 in real time. If the radiation level reaches the national emission standard, the first three-way solenoid valve 352 switches to the first branch pipe 353 passage, and the water in the pumping pipe 35 is directly discharged into the water storage tank 8. If the radiation level does not reach the national emission standard, the first three-way solenoid valve 352 switches to the first branch pipe 353 passage, and the water in the pumping pipe 35 is directly discharged into the water storage tank 8. The solenoid valve 352 switches to the second branch pipe 354 passage, and the water in the pumping pipe 35 enters the reverse osmosis membrane filter 6 for membrane separation, and then is discharged into the water storage tank 8. The sediment in the sedimentation tank 3 is discharged into the mixing chamber 53 of the solidification tank 5 through the sludge suction pipe 36 and the first waste liquid inlet pipe 531. The impurities in the reverse osmosis membrane filter 6 are discharged into the mixing chamber 53 of the solidification tank 5 through the clean sewage pipe 62 and the third waste liquid inlet pipe 533. Then, the glass substrate is poured into the mixing chamber 53 through the glass substrate inlet pipe 534. The stirring shaft 54 ​​drives the spiral stirring blade 541 to fully mix the sediment, impurities and glass substrate. While stirring, the ceramic melting furnace 51 starts to heat. After stirring is completed, the electromagnetic butterfly valve 52 is opened, and the mixture enters the ceramic melting furnace 51. Then, the electromagnetic butterfly valve 52 is closed. After the glass substrate is heated and melted, it becomes a fluid that encapsulates the sediment and impurities. Then, it is discharged into a cooling container for cooling and solidification. Finally, the cooled solidified material is placed into a sealed container for sealed storage or landfill.

[0023] When the amount of radioactive wastewater generated during nuclear decontamination is small, the radioactive wastewater is first stored in the nuclear wastewater collection tank 2. The second three-way solenoid valve 21 is switched to the fifth branch pipe 23 passage, and then enters the evaporator 4 through the fifth branch pipe 23 for high-temperature evaporation. The second pipeline filter 24 on the fifth branch pipe 23 filters out large particulate impurities in the radioactive wastewater. When the evaporator 4 evaporates the radioactive wastewater at high temperature, the water evaporates to form water vapor, which enters the condenser 9 to form condensate and then flows back to the water storage tank 8. The radioactive nuclides will not be evaporated and will remain in the water to form impurities. Then the impurities are discharged into the solidification tank 5 through the drain pipe 41 for solidification.

[0024] When the amount of radioactive wastewater generated during nuclear decontamination is large, or when nuclear decontamination-related equipment is needed during the replacement of wastewater in the source water well 1, the cost of evaporation treatment using evaporator 4 will be high. In this case, simply switch the second three-way solenoid valve 21 to the fourth branch pipe 22 passage, and discharge the wastewater into the nuclear wastewater collection tank 2 directly into the sedimentation tank 3 for sedimentation. Then, depending on the treatment effect of the sedimentation tank 3, choose whether to discharge it directly into the water storage tank 8 or to further treat it through the reverse osmosis membrane filter 6.

[0025] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of this utility model and not to limit it. Although the utility model has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of this utility model. Any modifications or equivalent substitutions that do not depart from the spirit and scope of this utility model should be covered within the protection scope of the claims of this utility model.

Claims

1. A radioactive wastewater treatment system, characterized by: The application relates to a nuclear waste water treatment device, which comprises a source water well, a nuclear waste water collecting tank, a sedimentation tank, an evaporator, a solidification tank and a reverse osmosis membrane filter, the source water well is connected with the sedimentation tank through a water outlet pipe, a storage hopper, a water pumping pipe and a suction pipe are arranged on the sedimentation tank, a flocculating agent is stored in the storage hopper, a connecting hole is formed in the water pumping pipe, a channel type radioactive substance monitor is arranged on the connecting hole in a sealing mode, a first three-way electromagnetic valve is arranged on the water outlet end of the water pumping pipe, a first branch pipe and a second branch pipe are connected with the first three-way electromagnetic valve, the first branch pipe is connected with a water storage tank, the second branch pipe is connected with the reverse osmosis membrane filter, the reverse osmosis membrane filter is connected with the water storage tank through a third branch pipe, the clean water pipe of the reverse osmosis membrane filter and the suction pipe of the sedimentation tank are connected with the solidification tank, a second three-way electromagnetic valve is arranged on the liquid outlet of the nuclear waste water collecting tank, a fourth branch pipe and a fifth branch pipe are connected with the second three-way electromagnetic valve, the fourth branch pipe is connected with the sedimentation tank, the fifth branch pipe is connected with the evaporator, a waste water outlet pipe of the evaporator is connected with the solidification tank, a steam outlet of the evaporator is connected with a condenser, and the condenser is connected with the water storage tank. A first pipeline filter is arranged on the water pumping pipe in front of the channel type radioactive substance monitor, and the filtering precision of the first pipeline filter is between 0.1 and 5 mu m.

2. The radioactive wastewater treatment system of claim 1, wherein: A second pipeline filter is arranged on the fifth branch pipe, and the filtering precision of the second pipeline filter is between 0.1 and 5 mu m.

3. The radioactive wastewater treatment system of claim 1, wherein: The evaporator is a thin film evaporator.

4. The radioactive wastewater treatment system of claim 1, wherein: The volume of the sedimentation tank is 1.3-1.5 times that of the source water well.

5. The radioactive wastewater treatment system of claim 1, wherein: A bearing table is fixed on the sedimentation tank, two storage hoppers are symmetrically arranged on the bearing table, the discharge pipes of the storage hoppers penetrate through the bearing table and extend into the sedimentation tank, a rotating shaft is rotatably arranged on the bearing table and extends into the sedimentation tank and is rotatably connected with the bottom wall of the sedimentation tank, a plurality of stirring blades are uniformly arranged on the rotating shaft, a driving mechanism for driving the rotating shaft to rotate is arranged on the bearing table, and the water pumping pipe and the suction pipe are arranged on the two sides of the sedimentation tank.

6. The radioactive wastewater treatment system of claim 1 or 5, wherein: The solidification tank comprises a ceramic melting furnace, an air exchange hole and a feeding port are arranged on the top of the ceramic melting furnace, an electromagnetic butterfly valve is flange-connected to the feeding port, a mixing bin is flange-connected to the electromagnetic butterfly valve, a stirring shaft is transversely arranged in the mixing bin, spiral stirring blades are arranged on the stirring shaft, a driving mechanism for driving the stirring shaft to rotate is arranged on the mixing bin, a first waste liquid feeding pipe, a second waste liquid feeding pipe, a third waste liquid feeding pipe and a glass substrate feeding pipe are arranged on the top of the mixing bin, the first waste liquid feeding pipe is connected with the suction pipe, the second waste liquid feeding pipe is connected with the waste water outlet pipe, and the third waste liquid feeding pipe is connected with the clean water pipe.

7. The radioactive wastewater treatment system of claim 1, wherein: ​

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