WO2019196143A1

WO2019196143A1 - Radioactive waste liquid treatment method and apparatus

Info

Publication number: WO2019196143A1
Application number: PCT/CN2018/085069
Authority: WO
Inventors: 赵璇; 李福志; 张猛
Original assignee: 清华大学
Priority date: 2018-04-13
Filing date: 2018-04-28
Publication date: 2019-10-17
Also published as: CN110379532A; CN110379532B

Abstract

Disclosed in the present application are a radioactive waste liquid treatment method and apparatus. The method comprises: performing separation on a radioactive waste liquid to obtain a first purified liquid and a concentrated liquid; removing radioactive nuclide from the concentrated liquid to obtain a second purified liquid, wherein removing radioactive nuclide from the concentrated liquid comprises performing a chemical precipitation process on the concentrated liquid; and discharging the first purified liquid and the second purified liquid. The radioactive waste liquid treatment method and apparatus in the present application have a high radioactive waste liquid purification level, and also significantly reduce the yield of radioactive waste, thereby minimizing the radioactive waste.

Description

Radioactive waste liquid processing method and device

Cross-reference to related applications

The present application claims the benefit of priority to the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the

Technical field

The present application relates to the technical field of radioactive waste liquid treatment, and in particular, to a method and a device for treating radioactive waste liquid.

Background technique

According to the salt content, the radioactive waste liquid can be divided into three categories: (1) low salinity radioactive waste liquid with a salt content of 0g·L ^-1 to 2g·L ^-1 ; (2) salt content is Medium-salt radioactive waste liquid of 2g·L ^-1 to 10g·L ^-1 ; (3) High-salt radioactive waste liquid with a salt content of 10g·L ^-1 or more.

It is very difficult to completely separate the salt and the radionuclide. Therefore, in the treatment of the radioactive waste liquid, for the radioactive waste liquid having a low salt content, the salt and the radionuclide are generally treated together as a treatment target. However, for radioactive waste liquids with high salt content, since the ratio of the amount of non-radioactive salts to the amount of radionuclides is usually greater than 10 ⁵ or even higher, non-radioactive salts and radionuclides are treated together as treatment targets. Most of the concentrate is non-radioactive, which greatly increases the amount of secondary radioactive waste.

Therefore, there is a need for a new method and apparatus for treating radioactive waste liquids to solve the above technical problems.

Summary of the invention

According to an embodiment of the present application, a method and apparatus for treating a radioactive waste liquid are provided, which have a higher level of purification, and at the same time, can significantly reduce the amount of radioactive waste generated, and achieve a small quantification of radioactive waste.

The radioactive waste liquid treatment method and apparatus according to the embodiments of the present application are particularly suitable for the treatment of high salinity radioactive waste liquid.

According to an aspect of an embodiment of the present application, a method for treating a radioactive waste liquid is provided, the method comprising: separating a radioactive waste liquid to obtain a first purifying liquid and a concentrated liquid; and removing the radioactive nuclides from the concentrated liquid, Obtaining a second purifying liquid, wherein the removing the radioactive nuclides from the concentrated liquid comprises: the concentrated liquid is subjected to a chemical precipitation process; and the first purified liquid and the second purified liquid are discharged.

According to the radioactive waste liquid treatment method of the embodiment of the present application, the first purification liquid that meets or even exceeds the discharge standard is obtained by separating the radioactive waste liquid, and the majority of the radioactive nuclide is retained in the concentrate, the concentrate It has a high radionuclide concentration and is treated by a chemical precipitation process to selectively remove radionuclides. Non-radioactive salts are discharged together with the purification liquid, and no radioactive concentrate is produced, thus greatly reducing non-radioactive The amount of salt entering the radioactive waste, thereby significantly reducing the amount of secondary radioactive waste generated. Compared with the direct chemical precipitation treatment of the radioactive waste liquid, the radioactive waste liquid in the method of the present application is greatly concentrated, the volume of the radioactive waste liquid to be treated is greatly reduced, and the concentration of the target radionuclide ion to be removed in the concentrated liquid is increased. It can greatly improve the decontamination factor of radioactive nuclides in the chemical precipitation process, thereby significantly reducing the amount of radioactive waste generated.

According to another aspect of embodiments of the present application, there is also provided a radioactive waste liquid processing apparatus, the apparatus comprising a separation unit, a chemical precipitation unit and a drainage unit, wherein a concentrate outlet of the separation unit is connected to an inlet of the chemical precipitation unit; The purification liquid outlet of the separation unit and the purification liquid outlet of the chemical precipitation unit are respectively connected to the drainage unit.

DRAWINGS

In order to explain the technical solutions of the embodiments of the present application, the drawings used in the embodiments of the present application will be briefly introduced. For those skilled in the art, without any creative work, Other drawings can be obtained from these figures.

FIG. 1 is a schematic view showing a process flow of a method for treating a radioactive waste liquid provided by an embodiment of the present application.

FIG. 2 is a schematic view showing a process flow of a method for treating a radioactive waste liquid provided by another embodiment of the present application.

FIG. 3 is a schematic view showing a process flow of a method for treating a radioactive waste liquid provided by still another embodiment of the present application.

FIG. 4 is a schematic diagram showing the process flow of a radioactive waste liquid processing apparatus provided by an embodiment of the present application.

FIG. 5 is a schematic diagram showing the process flow of a radioactive waste liquid processing apparatus according to another embodiment of the present application.

FIG. 6 is a schematic view showing the process flow of a radioactive waste liquid processing apparatus according to still another embodiment of the present application.

FIG. 7 is a flow chart showing the process of a radioactive waste liquid processing apparatus provided by another embodiment of the present application.

Label description:

10, water inlet buffer tank;

20, water supply pump;

100, a preprocessing unit;

101, a degreasing filter; 102, an inorganic membrane filter;

200, a separation unit;

201, buffer water tank; 202, security filter; 203, high pressure pump; 204, buffer water tank; 205, circulation pump;

210, reverse osmosis subunit; 211, first stage reverse osmosis equipment; 212, second stage reverse osmosis equipment; 213, reverse osmosis equipment;

221, first-stage continuous electric desalination equipment; 222, second-stage continuous electric desalination equipment; 223, continuous electric desalination equipment; 224, intermediate water tank; 225, activator tank;

230, an ion exchange subunit;

310, a chemical precipitation unit; 311, a chemical precipitation reactor;

320, an inorganic adsorption unit; 321, an inorganic adsorption column;

400, drainage unit; 410, monitoring the discharge tank.

detailed description

The present application will be further described in detail below with reference to the accompanying drawings and embodiments. It is understood that the specific embodiments described herein are only to be construed as illustrative and not limiting. The application may be practiced without some of these specific details, as will be apparent to those skilled in the art. The following description of the embodiments is merely provided to provide a better understanding of the invention

It should be noted that, in this context, relational terms such as first and second are used merely to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply such entities or operations. There is any such actual relationship or order between them. Furthermore, the term "comprises" or "comprises" or "comprises" or any other variations thereof is intended to encompass a non-exclusive inclusion, such that a process, method, article, or device that comprises a plurality of elements includes not only those elements but also Other elements, or elements that are inherent to such a process, method, item, or device. An element that is defined by the phrase "comprising", without limiting the invention, does not exclude the presence of additional elements in the process, method, article, or device.

The concentration of radionuclide ions in radioactive wastewater is extremely low, and the concentration of radionuclide ions is further reduced to achieve an environmental emission requirement of less than 10 Bq/L, which is very important for the treatment capacity of radioactive wastewater treatment technology. High requirements. Some radioactive waste waters have a non-radioactive salt content of 10g·L ^-1 or more, or even higher. The prior art treats non-radioactive salts together with radionuclides as treatment targets, so that the amount of secondary radioactive waste is greatly increased. An important principle of radioactive wastewater treatment is the requirement for small quantification of radioactive waste. In addition, the operability and maintainability of the equipment under radioactive conditions need to be considered.

Based on the above special requirements of radioactive wastewater treatment, the embodiments of the present application provide a radioactive waste liquid treatment method and device, which have a higher purification level, and significantly reduce the amount of radioactive waste generated, thereby achieving a small quantification of radioactive waste.

In this paper, the "concentration factor" is calculated as (influent volume) / (volume of concentrate); "removal rate" is (by mass concentration of radionuclide in the influent - mass concentration of radionuclide in the produced water) / ( Calculation of the mass concentration of radionuclides in the influent; "recovery rate" is calculated as (water production) / (influent water); "decontamination factor" is (radiation activity of influent water) / (radiation activity of water production) ) Calculation.

The method and device for treating radioactive waste liquid provided by the embodiments of the present application are particularly suitable for the treatment of high salinity radioactive waste liquid.

FIG. 1 is a schematic view showing a process flow of a method for treating a radioactive waste liquid provided by an embodiment of the present application, according to which:

The radioactive waste water is first separated and treated to obtain a first purified liquid and a concentrated liquid. Wherein, the concentration factor can be more than 2 times, such as 2 to 10 times, and most of the radioactive nuclides in the radioactive waste water are retained in the concentrate, so that the mass concentration of the radionuclide in the concentrate can reach the radioactivity in the radioactive waste liquid. The mass concentration of the radionuclide is more than twice that of the radionuclides, and the mass concentration of the radionuclide in the first purification liquid is lower than the mass concentration of the radionuclide in the radioactive waste water, which is even better than the emission standard and is discharged.

Further, the concentrated liquid is subjected to removal of radionuclide treatment to obtain a second purification liquid. The method comprises the steps of: subjecting the concentrated liquid to a chemical precipitation process, and removing the radionuclide by adding a chemical precipitating agent to the concentrated liquid to promote the conversion of the radioactive nuclide ions into a poorly soluble substance to precipitate and precipitate. The chemical precipitant may be one or more of carbonate, phosphate, sulfide, sulfate, hydroxide, metal oxide, oxalic acid, oxalate, but is not limited thereto, as long as it can achieve radioactivity The nuclide is converted into a poorly soluble substance and precipitated. Because chemical precipitation only selectively removes radionuclides, the majority of non-radioactive ions such as Na ⁺ , K ⁺ , Cl ^- ,

OH ^- etc. does not work. Non-radioactive salts are discharged together with the purification liquid, and no radioactive concentrated waste liquid is produced. This greatly reduces the amount of non-radioactive salts entering the radioactive waste, thereby significantly reducing the amount of secondary radioactive waste generated. . The dosage of the chemical precipitant in the chemical precipitation is directly related to the ion concentration of the radionuclide in the solution and the removal rate required. Since the concentrate has a high concentration of radionuclides, it is treated by a chemical precipitation process. Compared with directly discharging the radioactive waste liquid, the radioactive waste liquid is greatly concentrated, the volume of the radioactive waste liquid to be treated is greatly reduced, and the concentration of the target radionuclide ion to be removed in the concentrate is increased, and the chemical can be greatly improved. The precipitation process has a significant reduction in the decontamination factor of the radionuclide, the chemical precipitant required to achieve the same removal rate, or the removal rate of the same chemical precipitant dosage, thereby significantly reducing the amount of radioactive waste generated.

After detecting that the activity of the second purification liquid meets the requirements of the discharge standard, the discharge treatment may be performed, and the first purification liquid and the second purification liquid may be directly discharged, that is, the first purification liquid is discharged through one pipeline, and the second purification is performed. The liquid is discharged through the second line; or the two may be mixed and discharged, that is, the second purified liquid is merged with the first purified liquid through the first line, and then drained. After detecting that the second purification liquid is mixed with the first purification liquid and meets the requirements of the discharge standard, the second purification liquid is mixed with the first purification liquid through the first pipeline and then discharged.

It is often difficult to obtain a high decontamination factor by chemical precipitation. If the second purification liquid discharged can achieve a lower activity, the chemical precipitation process can further remove the radionuclide by selective inorganic adsorption, thereby improving Decontamination factor for radionuclides. Among them, the concentrated liquid is subjected to a chemical precipitation process and then subjected to an inorganic adsorption process, which can reduce the processing load of the inorganic adsorption process.

According to some embodiments of the present application, the separation treatment may adopt one or more of a nanofiltration process, a reverse osmosis process, and a continuous electric desalination process according to actual conditions such as the composition, content, and processing requirements of the radioactive waste water. The combined process, or a combination of one or more of a nanofiltration process, a reverse osmosis process, and a continuous electric desalination process, and an ion exchange process.

When the separation treatment process adopts the reverse osmosis process, the first-stage or two-stage reverse osmosis process can be used, but it is not limited thereto, and the three-stage reverse osmosis process can also be adopted according to the actual situation.

As an example, the separation treatment process adopts a first-stage reverse osmosis process, specifically, the radioactive waste liquid is subjected to a first-stage reverse osmosis process to obtain a first-stage reverse osmosis purification liquid and a first-stage reverse osmosis concentrate as the first purification liquid and Concentrate.

Alternatively, the reverse osmosis process may employ one or two or more stages of reverse osmosis treatment. When two or more stages of reverse osmosis treatment are used, the upper stage reverse osmosis treatment intermediate concentrate is used as the feed water of the next stage of reverse osmosis treatment, ie The radioactive waste liquid is subjected to reverse osmosis treatment in two or more stages to obtain a concentrated liquid. At the same time, the purified liquid is sent out from each section, and the purified liquid sent from all the sections is combined into a first-stage reverse osmosis purification liquid, which can improve the recovery rate of reverse osmosis. .

As another example, the separation treatment process adopts a two-stage reverse osmosis process to further improve the level of reverse osmosis purification. Specifically, the radioactive waste liquid is first sent to the first-stage reverse osmosis process to obtain the first-stage reverse osmosis purification liquid and The first stage reverse osmosis concentrate is sent to the second stage reverse osmosis process to obtain the second stage reverse osmosis purification liquid and the second stage reverse osmosis concentrate. Wherein, the second-stage reverse osmosis concentrate is returned to the first-stage reverse osmosis process, and the first-stage reverse osmosis concentrate is sent to the chemical precipitation process as the concentrated liquid; the second-stage reverse osmosis purification liquid is lower than 10 Bq/ L, in line with the requirements of the discharge standard, as the first purification liquid for discharge treatment.

Optionally, the first-stage reverse osmosis process may adopt one or two or more stages of reverse osmosis treatment. When two or more stages of reverse osmosis treatment are used, the stage-level concentrate produced by the reverse osmosis treatment of the previous stage is used as the next stage of reverse osmosis treatment. The influent water, that is, the radioactive waste liquid is sequentially subjected to reverse osmosis treatment of two or more stages to obtain a concentrated liquid, and at the same time, the purified liquid is sent out from each section, and the purified liquid sent from all the sections is merged into the first-stage reverse osmosis purification liquid.

Alternatively, the second-stage reverse osmosis process may employ one or two or more stages of reverse osmosis treatment. Similarly, when two or more stages of reverse osmosis treatment are used, the stage-stage concentrate produced by the previous stage of reverse osmosis treatment is used as the next stage. The influent treated by reverse osmosis, that is, the radioactive waste liquid is subjected to reverse osmosis treatment of two or more stages in turn to obtain a second-stage reverse osmosis concentrate, and the purified liquid is sent from each section, and the purified liquid sent from all the sections is merged into the second. Grade reverse osmosis purification solution.

As an alternative, the first-stage reverse osmosis process and the second-stage reverse osmosis process all adopt three-stage reverse osmosis treatment to form a “two-stage three-stage” reverse osmosis process for separation of radioactive wastewater pairs, which has high purification. Capacity and concentration factor reduce the load on the chemical precipitation treatment process while increasing recovery.

When the first-stage reverse osmosis purification liquid produced by the first-stage reverse osmosis process or the second-stage reverse osmosis purification liquid produced by the two-stage reverse osmosis process has a radioactivity of more than 10 Bq/L, or if the first emission is pursued When the purification liquid can achieve lower radioactivity, the first-stage reverse osmosis purification liquid produced by the first-stage reverse osmosis process or the second-stage reverse osmosis purification liquid produced by the two-stage reverse osmosis process can be sent to the continuous electric elimination. The salt process (shown in Figure 2) or the ion exchange process (shown in Figure 3) is further refined.

As an example, the first-stage reverse osmosis purification liquid produced by the first-stage reverse osmosis process or the second-stage reverse osmosis purification liquid produced by the two-stage reverse osmosis process is subjected to a first-stage continuous electric desalination process for fine treatment to obtain the first Purification liquids often meet the requirements of emission standards, even reach the natural background level, contain almost no radionuclides, and discharge treatment. The first-stage continuous electric desalting concentrate is returned to the first-stage reverse osmosis process or two-stage reverse osmosis. The first stage reverse osmosis process in the process.

In order to improve the purification level of the continuous electric desalination process, the activator may be added to the second-stage reverse osmosis purification liquid produced by the first-stage reverse osmosis process or the second-stage reverse osmosis purification liquid produced by the two-stage reverse osmosis process, and then sent. Into the first-stage continuous electric desalination process for deep purification treatment. The activator can be prepared from pure water having a resistivity of more than 0.5 MΩ·cm and different kinds of inorganic salts, and the activator contains ions Ca ²⁺ , Na ⁺ , Sr ²⁺ , Zn ²⁺ , Mg ²⁺ , Fe ^{2 . +} and K ⁺ , the type of anion is not limited, the concentration of the activator stock solution is related to the dosage, ensuring that the ion concentration in the radioactive waste water is as follows after the activator is added to the radioactive waste water and mixed uniformly: Ca ²⁺ 0.1 mg / L ~ 0.2 mg/L, Na ⁺ 0.2 mg/L to 0.3 mg/L, Sr ²⁺ 8 mg/L to 9 mg/L, Zn ²⁺ 18 mg/L to 20 mg/L, Mg ²⁺ 0.2 mg/L to 0.25 mg/ L, Fe ²⁺ 0.04 mg/L to 0.05 mg/L and K ⁺ 100 mg/L to 150 mg/L.

As another example, the first-stage reverse osmosis purification liquid produced by the first-stage reverse osmosis process or the second-stage reverse osmosis purification liquid produced by the two-stage reverse osmosis process is subjected to a two-stage continuous electric desalination process for fine treatment, specifically Firstly, the first-stage reverse osmosis purification liquid produced by the first-stage reverse osmosis process or the second-stage reverse osmosis purification liquid produced by the two-stage reverse osmosis process is sent to the first-stage continuous electric desalination process to obtain the first-stage continuous process. The electric demineralization purification liquid and the first-stage continuous electric demineralization concentrate, and then the first-stage continuous electric demineralization purification liquid is sent to the second-stage continuous electric desalination process to obtain the second-stage continuous electric desalting purification liquid and The second-stage continuous electric demineralization concentrate, wherein the second-stage continuous electric desalination purification liquid is the first purification liquid, which has already reached the requirements of the discharge standard, and even reaches the natural background level, and performs the discharge treatment, the first stage The continuous electric desalting concentrate and the second-stage continuous electric desalting concentrate return to the first-stage reverse osmosis process in the first-stage reverse osmosis process or the two-stage reverse osmosis process.

Similarly, in order to further improve the purification level of the continuous electric desalination process, an activator may be added to the first-stage continuous electric desalination purification liquid, and then sent to a second-stage continuous electric desalination process for purification treatment. The activator may be selected from an activator as described above.

The fine treatment may also be an ion exchange process using one or more stages. The purified liquid obtained by the first-stage or two-stage reverse osmosis process is sequentially subjected to one or more ion exchange processes to obtain a first purified liquid.

It can be understood that the separation treatment process is not limited to adopting the above process, for example, it may be a continuous electric desalination process of more than one level; a nanofiltration-reverse osmosis combination process; a nanofiltration-continuous electric desalination combination process; Reverse osmosis-continuous electric desalination combined process; nanofiltration-reverse osmosis-ion exchange combination process, etc., can be determined by those skilled in the art according to actual conditions.

The radioactive waste water is optionally pretreated before the radioactive waste water is separated, but this is not an essential process.

In addition to radionuclides and inorganic salts, radioactive waste water may also contain impurities such as oils, colloids, and particulate matter. Most of these impurities are non-radioactive, but they may affect processes such as reverse osmosis, chemical precipitation, and inorganic adsorption. The removal of these impurities can prolong the life cycle of the reverse osmosis membrane and the inorganic adsorbent, reduce the replacement of the reverse osmosis membrane and the inorganic adsorbent, improve the efficiency of the chemical precipitant, and further reduce the amount of radioactive waste inorganic adsorbent and radioactive chemical precipitation. The amount of matter produced.

It is also possible to adjust the pH value of the radioactive waste water to 6-8 in advance, which can make the reverse osmosis process better, and the reverse osmosis membrane has a longer service life.

In order to achieve the above method for treating a radioactive waste liquid, the embodiment of the present application further provides a radioactive waste liquid processing apparatus, which will be described in detail below with reference to FIGS. 4 to 7.

FIG. 4 is a schematic diagram showing the process flow of a radioactive waste liquid processing apparatus provided by an embodiment of the present application. The apparatus includes a separation unit 200, a chemical precipitation unit 310, and a drainage unit 400, wherein the concentrate outlet of the separation unit 200 is connected to the inlet of the chemical precipitation unit 310; the purification liquid outlet of the separation unit 200 and the purification liquid outlet of the chemical precipitation unit 310 Connected to the drain unit 400, respectively.

As an example, the drainage unit 400 includes a first drainage subunit and a second drainage subunit (not shown), the purification liquid outlet of the separation unit 200 is connected to the first drainage subunit, and the purification liquid outlet of the chemical precipitation unit 310 Connected to the second drainage subunit, the first drainage subunit and the second drainage subunit may be in communication. In this way, when the activity of the second purification liquid is determined to meet the requirements of the emission standard, the first purification liquid and the second purification liquid may be directly discharged according to different requirements, or may be discharged after mixing the two; When the second purification liquid is mixed with the first purification liquid and meets the requirements of the discharge standard, the second purification liquid is mixed with the first purification liquid and discharged.

It can be understood that the drainage unit 400 may be only a drainage pipe, or may be connected to the drainage discharge tank 410 (as shown in FIG. 6 and FIG. 7) on the drainage pipe to monitor the drainage activity, or other purification liquid. The form of discharge is not limited in this application.

If a higher decontamination factor is pursued, the apparatus further includes an inorganic adsorption unit 320; the purification liquid outlet of the chemical precipitation unit 310 is connected to the drainage unit 400 via the inorganic adsorption unit 320.

According to some embodiments of the present application, referring to FIG. 6 and FIG. 7, the chemical precipitation unit 310 employs a chemical precipitation reactor 311, which may be an integrated precipitation device capable of performing dosing, chemical precipitation reaction, and separation, and the chemical precipitant may be Using one or more of carbonate, phosphate, sulfide, sulfate, hydroxide, metal oxide, oxalic acid, oxalate, but not limited thereto, as long as the radionuclide can be converted into Insoluble matter can be precipitated.

According to some embodiments of the present application, referring to FIG. 6 and FIG. 7 , the inorganic adsorption unit 320 adopts an inorganic adsorption column 321 , and may adopt an inorganic adsorption column for ruthenium, an inorganic adsorption column for ruthenium, and an inorganic adsorption column for ruthenium and osmium. More than one of them.

According to some embodiments of the present application, the separation unit 200 includes one or a combination of two or more of a nanofiltration unit, a reverse osmosis subunit, a continuous electric desalting subunit. According to further embodiments of the present application, the separation unit 200 includes one or more of a nanofiltration unit, a reverse osmosis subunit, a continuous electric desalting subunit, and a combination of ion exchange subunits.

As an example, referring to FIG. 5 to FIG. 7 , the separation unit 200 includes a reverse osmosis subunit 210, and the reverse osmosis subunit 210 adopts a first- or two-stage reverse osmosis device, but is not limited thereto, and may be adopted according to actual conditions. Three-stage reverse osmosis equipment.

In some embodiments, referring to FIG. 6, a reverse osmosis unit 210 employs a primary reverse osmosis device, and a concentrate outlet of the reverse osmosis device 213 is coupled to the inlet of the chemical precipitation unit 310. The purification liquid sent from the reverse osmosis apparatus 213 has been lower than 10 Bq/L, which meets the requirements of the discharge standard, and can be discharged. At this time, the purification liquid outlet of the reverse osmosis apparatus 213 is connected to the drainage unit 400.

In order to increase the recovery rate of reverse osmosis, the concentrate outlet of the reverse osmosis apparatus 213 is divided into two branches via a pipe, one branch is connected to the inlet of the reverse osmosis device 213, and the other branch is connected to the inlet of the chemical precipitation unit 310. This also reduces the discharge amount of the concentrate, reduces the load of the chemical precipitation unit 310, further improves the utilization rate of the chemical precipitant, and avoids energy waste and saves energy.

Further, the reverse osmosis device 213 may employ one reverse osmosis membrane module or two or more reverse osmosis membrane modules in series. When two or more reverse osmosis membrane modules are used, the concentrate outlet of the previous reverse osmosis membrane module is next to the next The inlet of the reverse osmosis membrane module is connected, that is, the stage-level concentrate produced by the previous reverse osmosis membrane module is used as the inlet water of the next reverse osmosis membrane module, and the stage-level purification liquids sent from all the reverse osmosis membrane modules are merged into the reverse osmosis apparatus 213. Purification fluid.

In some embodiments, referring to the process flow diagram of the radioactive waste liquid processing apparatus provided by one embodiment of the present application shown in FIG. 7, the reverse osmosis subunit 210 employs a two-stage reverse osmosis apparatus, wherein the first stage reverse osmosis apparatus 211 and The second reverse osmosis device 212 is connected in two stages. Specifically, the purified liquid outlet of the first-stage reverse osmosis device 211 is connected to the inlet of the second-stage reverse osmosis device 212, and the concentrated liquid outlet of the second-stage reverse osmosis device 212 is The inlet of the primary reverse osmosis apparatus 211 is connected, and the concentrate outlet of the first stage reverse osmosis apparatus 211 is connected to the inlet of the chemical precipitation unit 310. The purification liquid sent from the second-stage reverse osmosis apparatus 212 is lower than 10 Bq/L, and meets the requirements of the discharge standard, and the discharge treatment can be performed. At this time, the purification liquid outlet of the first-stage reverse osmosis apparatus 212 is connected to the drainage unit 400.

In order to increase the recovery rate of reverse osmosis, the concentrate outlet of the first-stage reverse osmosis apparatus 211 is divided into two branches via a pipeline, one branch is connected to the inlet of the first-stage reverse osmosis apparatus 211, and the other branch is chemically precipitated. The inlets of unit 310 are connected. This also reduces the discharge amount of the concentrate, reduces the load of the chemical precipitation unit 310, further improves the utilization rate of the chemical precipitant, and avoids energy waste and saves energy.

Further, the first-stage reverse osmosis device 211 may adopt a reverse osmosis membrane module or two or more reverse osmosis membrane modules connected in series, and when more than two reverse osmosis membrane modules are used, the concentrate outlet of the previous reverse osmosis membrane module Connected to the inlet of the next reverse osmosis membrane module, that is, the stage-level concentrate produced by the previous reverse osmosis membrane module is used as the inlet water of the next reverse osmosis membrane module, and the stage-level purification liquids sent from all the reverse osmosis membrane modules are merged into the first The purification liquid of the reverse osmosis apparatus 211.

The second stage reverse osmosis apparatus 212 may also be in series with one reverse osmosis membrane module or two or more reverse osmosis membrane modules, and similarly, when two or more reverse osmosis membrane modules are used, the last reverse osmosis membrane module The concentrate outlet is connected to the inlet of the next reverse osmosis membrane module, that is, the stage-level concentrate produced by the previous reverse osmosis membrane module is used as the inlet water of the next reverse osmosis membrane module, and the stage-level purification liquids sent from all the reverse osmosis membrane modules are combined. It is a purification liquid of the second-stage reverse osmosis device 212.

As an alternative, the first-stage reverse osmosis device 211 and the second-stage reverse osmosis device 212 are all connected in series by a three-stage reverse osmosis membrane module to form a "two-stage three-stage" reverse osmosis subunit 210 for separating and treating radioactive waste water. It has a higher purification capacity and concentration factor, reduces the load of the chemical precipitation unit 310, and increases the recovery rate of reverse osmosis.

When the first-stage reverse osmosis purification liquid produced by the first-stage reverse osmosis equipment or the second-stage reverse osmosis purification liquid produced by the two-stage reverse osmosis equipment has a radioactivity of more than 10 Bq/L, or when pursuing the discharged purification liquid When a lower activity can be achieved, a continuous electric desalting subunit (as shown in Figures 6 and 7) or an ion exchange subunit 230 (shown in Figure 5) can be disposed downstream of the reverse osmosis subunit. The first-stage reverse osmosis purification liquid produced by the first-stage reverse osmosis apparatus or the second-stage reverse osmosis purification liquid produced by the two-stage reverse osmosis process is sent to the continuous electric desalination unit or the ion exchange subunit 230 for further fine processing. .

In some embodiments, referring to FIG. 6, the continuous electric desalination unit uses a first-stage continuous electric desalination apparatus, and the purification liquid outlet of the reverse osmosis subunit 210 is connected to the inlet of the continuous electric desalination apparatus 223 for continuous electric desalination. The purge liquid outlet of the apparatus 223 is connected to the drain unit 400, and the concentrate outlet of the continuous electric desalination apparatus 223 is connected to the inlet of the reverse osmosis subunit 210. When the reverse osmosis subunit 210 employs a primary reverse osmosis apparatus, please refer to FIG. 6. The inlet of the reverse osmosis subunit 210 refers to the inlet of the reverse osmosis apparatus 213; when the reverse osmosis subunit 210 employs a two-stage reverse osmosis apparatus, Referring to FIG. 7, the inlet of the reverse osmosis subunit 210 refers to the inlet of the first stage reverse osmosis apparatus 211.

In some embodiments, referring to FIG. 7, the continuous electric desalination unit uses a two-stage continuous electric desalination apparatus, wherein the first-stage continuous electric desalination apparatus 221 is connected in series with the second-stage continuous electric desalination apparatus 222, specifically The purification liquid outlet of the reverse osmosis subunit 210 is connected to the inlet of the first stage continuous electric desalination apparatus 221, and the purification liquid outlet of the first stage continuous electric desalination apparatus 221 is connected to the inlet of the second stage continuous electric desalination apparatus 222. The purification liquid outlet of the second-stage continuous electric desalination apparatus 222 is connected to the drainage unit 400, and the concentrated liquid outlet of the first-stage continuous electric desalination apparatus 221 and the concentrated liquid outlet of the second-stage continuous electric desalination apparatus 222 are respectively reversed The inlets of the permeation subunits 210 are connected.

In order to improve the purification level of the continuous electric desalination unit, when the continuous electric desalination unit adopts the first-stage continuous electric desalination device, an intermediate water tank may be connected between the reverse osmosis subunit and the continuous electric desalination unit. The intermediate tank is connected to the activator tank. In this way, in the purification liquid sent by the reverse osmosis subunit, such as the first-stage reverse osmosis purification liquid produced by the first-stage reverse osmosis apparatus or the second-stage reverse osmosis purification liquid produced by the two-stage reverse osmosis apparatus, the activator is added, and then sent Into a first-class continuous electric desalination equipment for deep purification treatment. When the continuous electric desalination unit is connected in series by two-stage continuous electric desalination equipment, referring to FIG. 7, an intermediate water tank can be connected between the first-stage continuous electric desalination device 221 and the second-stage continuous electric desalination device 222. 224, the intermediate water tank 224 is connected to the activator tank 225, and a dosing pump is provided to control the amount of the activator to be added, so that the purified liquid produced by the continuous electric desalination unit can reach the natural background level.

The fine treatment of the ion exchange subunit 230 may be performed by using one or more ion exchangers in series, and the first, two, three, four or more ion exchangers may be used according to actual conditions.

As shown in FIG. 4, the pre-processing unit 100 may be provided upstream of the separation unit 200, but is not essential. If necessary, the pre-processing unit 100 may be one or a combination of a degreasing filter, an activated carbon filter, an inorganic membrane filter, a security filter, a paper core filter, a self-cleaning filter, and an ultrafilter. .

In addition to radionuclides and inorganic salts, radioactive waste water may also contain impurities such as oils, colloids, and particulate matter. Most of these impurities are non-radioactive, but they will affect subsequent processes. Pretreatment to remove these impurities can extend The use period of the reverse osmosis membrane and the inorganic adsorbent reduces the replacement of the inorganic adsorbent and the reverse osmosis membrane, improves the utilization efficiency of the chemical precipitant, and further reduces the amount of radioactive waste inorganic adsorbent generated and the amount of radioactive chemical precipitated sludge. The degreasing filter 101 can stably remove oil in the radioactive waste water for a long period of time, and the inorganic membrane filter 102 can further remove oil in the radioactive waste water, and can effectively remove colloids and particulate matter in the radioactive waste water, as shown in FIG. 5 to FIG. 7 . As shown, the degreasing filter 101 and the inorganic membrane filter 102 are sequentially connected to pretreat the radioactive waste water, and the turbidity is strong, and the pretreatment process equipment and the flow are simplified.

The separation unit 200 also includes a buffer tank 201 to buffer the radioactive wastewater from the pretreatment unit 100. A security filter 202 is further coupled between the buffer tank 201 and the reverse osmosis subunit 210 for protecting the reverse osmosis apparatus of the subsequent process. The separation unit 200 may further include a buffer tank 204 to buffer the purge liquid sent from the reverse osmosis subunit 210.

The apparatus also includes a suitable water supply pump 20, a high pressure pump 203, and a circulation pump 205, which may be various pumps commonly used in the art, such as a plunger pump, a centrifugal pump, and the like. The apparatus may also include a water inlet buffer tank 10 to buffer the radioactive waste water.

By adopting the radioactive waste water device provided in the embodiment of the present application, the above-mentioned radioactive waste water method can be implemented to achieve a high level of radioactive waste liquid purification, and at the same time, the amount of radioactive waste generated can be significantly reduced, and the radioactive waste can be quantified.

The present application is exemplified by the following examples, but these examples are in no way intended to limit the application.

The ion concentrations in the following examples were determined by inductively coupled plasma-mass spectrometry (ICP-MS), and the concentrations of the oils were characterized using a total organic carbon TOC analyzer.

Example 1

The radioactive waste water treatment device used in this embodiment is different from the device shown in FIG. 6 in that no continuous electric desalination device 223 is provided, that is, the purification liquid outlet of the reverse osmosis device 213 is directly connected to the monitoring discharge tank 410, and other parts and figures are shown. The device shown in 6 is the same. The reverse osmosis device 213 is a three-stage reverse osmosis device formed by connecting three reverse osmosis membrane modules in series, the chemical precipitation reactor 311 adopts an integrated precipitation device, and the inorganic membrane filter 102 uses a ceramic membrane.

The simulated radioactive waste water treated in this example contained Cs ⁺ 10 mg/L, Sr ²⁺ 10 mg/L, NaCl 10 g/L, and the oil content was 100 ppm.

The designed treatment capacity of the radioactive waste water treatment device is 1 m ³ /h.

After the simulated radioactive waste water passed through the degreasing filter 101, the oil content was reduced from 100 ppm to 5 ppm. After further passing through the inorganic membrane filter 102, the oil content was lowered to 1 ppm to satisfy the subsequent influent conditions.

The reverse osmosis operating pressure is 5 MPa, and the simulated radioactive wastewater is highly concentrated by the first-stage reverse osmosis process. The recovery rate of reverse osmosis is set to 80%, the concentration multiple is 5 times, and the concentration of radionuclide in the concentrate is increased by 5 times, of which Cs ⁺ concentration The concentration was 49 mg/L, Sr ²⁺ was 50 mg/L, and the NaCl concentration was 49.5 g/L. According to the principle of chemical precipitation, under a certain solubility product Ksp, when the concentration of cation is increased by 5 times, the required concentration of anionic agent can be reduced by 5 times, and at the same time, since the amount of concentrated water is reduced to 1/5 of the amount of raw water, chemistry The amount of precipitant used is reduced to 1/25 of the original requirement, which can greatly improve the decontamination factor of the radionuclide by the chemical precipitation process and greatly reduce the amount of radioactive solid waste generated.

Since the amount of treated water is reduced, the chemical precipitation reaction can be carried out in an integrated precipitation apparatus, and the chemical precipitating agent can be one or a combination of two or more of ferrous hydroxide, calcium carbonate, manganese dioxide, barium sulfate, and the like. In the examples, the chemical precipitant used calcium carbonate. After chemical precipitation, the concentration of Sr ²⁺ is reduced to 0.5 mg/L, while the chemical precipitation process has no removal effect on NaCl. After chemical precipitation, the NaCl concentration is kept at 49.5 g/L, so NaCl is not present in the solid waste. Reduced solid waste content.

Since the chemical precipitation process has a low decontamination effect on Cs ⁺ , the chemical precipitation process produces water further into the 铯 adsorption bed for inorganic adsorption to remove 铯, the decontamination factor reaches 10 ³ , and the inorganic adsorption process produces water (ie, the second purification liquid). The concentration of Cs ^{+ was} decreased to 49 μg / L, the concentration of Sr ²⁺ was 0.5 mg / L, the concentration of NaCl was 49.5 g / L, and the water yield was 0.2 m ³ / h.

The concentration of Cs ^{+ in the} reverse osmosis process water production (ie, the first purification liquid) was 100 μg/L, the concentration of Sr ²⁺ was 10 μg/L, the concentration of NaCl was 0.125 g/L, and the water production was 0.8 m ³ /h. The first purification liquid is mixed with the second purification liquid and discharged, and the concentration of Cs ⁺ is 89.8 μg/L, the concentration of Sr ²⁺ is 108 μg/L, the concentration of NaCl is 10 g/L, and the whole device is decontaminated against sputum and sputum. The factor is approximately 100.

It is also possible to provide a continuous electric desalination device after the reverse osmosis device 213 to achieve a higher decontamination factor.

The foregoing is only a specific embodiment of the present application, and it should be understood that the scope of protection of the present application is not limited thereto, and any person skilled in the art can easily think of each within the technical scope disclosed in the present application. Equivalent modifications or substitutions are intended to be included within the scope of the present application.

Claims

A method of treating a radioactive waste liquid, wherein the method comprises:

Separating the radioactive waste liquid to obtain a first purification liquid and a concentrated liquid;

Performing the removal of the radionuclide treatment to obtain a second purification liquid; wherein the removing the radioactive nuclides on the concentrated liquid comprises treating the concentrated liquid through a chemical precipitation process;

The first purification liquid and the second purification liquid are discharged.
The method according to claim 1, wherein said removing the radionuclide treatment of said concentrate further comprises an inorganic adsorption process;

Wherein, the concentrated liquid is treated by the chemical precipitation process, and then subjected to an inorganic adsorption process to obtain the second purified liquid.
The method according to claim 1, wherein the separation treatment employs one or a combination of one of a nanofiltration process, a reverse osmosis process, a continuous electric desalination process, or a nanofiltration process, reverse osmosis A combination process of one or more of a process, a continuous electric desalination process, and an ion exchange process.
The method according to claim 1, wherein said separating the radioactive waste liquid to obtain the first purified liquid and the concentrated liquid comprises: treating the radioactive waste liquid by a one-stage or two-stage reverse osmosis process.
The method according to claim 4, wherein said reverse osmosis process employs one or two or more stages of reverse osmosis treatment, and when two or more stages of reverse osmosis treatment are employed, the intermediate stage of the previous stage of reverse osmosis treatment is used as the next stage. The infiltration water of the reverse osmosis treatment, the purified liquid sent from each section is merged into the purification liquid of the reverse osmosis process.
The method of claim 4 wherein said two-stage reverse osmosis process comprises:

The radioactive waste liquid is sequentially processed through the first-stage reverse osmosis process and the second-stage reverse osmosis process, and the second-stage reverse osmosis concentrate sent from the second-stage reverse osmosis process is returned to the first-stage reverse osmosis process. The first stage reverse osmosis process delivers the concentrate.
The method of claim 4, wherein after the treating the radioactive waste liquid through the one-stage or two-stage reverse osmosis process, the method further comprises:

Treating the purified liquid obtained by the first-stage or two-stage reverse osmosis process through a first-stage or two-stage continuous electric desalination process; or

The purified liquid obtained by the first-stage or two-stage reverse osmosis process is treated by one or more ion exchange processes.
The method of claim 7 wherein said two-stage continuous electrical desalination process comprises:

Purifying the liquid obtained by the first-stage or two-stage reverse osmosis process through a first-stage continuous electric desalination process and a second-stage continuous electric desalination process to obtain the first purification liquid; The first-stage continuous electric desalting concentrate sent by the continuous electric desalination process and the second-stage continuous electric desalting concentrate sent by the second-stage continuous electric desalination process return to the first- or two-stage reverse osmosis Process.
The method according to claim 8, wherein an activator is added to the intermediate cleaning liquid sent from the first-stage continuous electric desalination process, and then sent to the second-stage continuous electric desalination process.
The method according to claim 1, wherein the volume of the radioactive waste liquid is more than twice the volume of the concentrated liquid, and the concentration of the radionuclide in the concentrated liquid is a radionuclide in the radioactive waste liquid. The concentration is more than 2 times.
The method according to claim 1, wherein the radioactive waste liquid is subjected to pretreatment to remove one or more of oils, colloids, particles, and/or pH values before the separation treatment.
A radioactive waste liquid processing apparatus, wherein the apparatus comprises a separation unit, a chemical precipitation unit, and a drainage unit, wherein

a concentrated liquid outlet of the separation unit is connected to an inlet of the chemical precipitation unit;

The purification liquid outlet of the separation unit and the purification liquid outlet of the chemical precipitation unit are respectively connected to the drainage unit.
The apparatus according to claim 12, wherein the apparatus further comprises an inorganic adsorption unit; the purification liquid outlet of the chemical precipitation unit is connected to the drainage unit via the inorganic adsorption unit.
The apparatus according to claim 12, wherein said separation unit comprises one of a nanofiltration unit, a reverse osmosis subunit, a continuous electric desalting subunit, or a combination of two or more; or, said separation unit comprises A combination of one or more of a nanofiltration unit, a reverse osmosis subunit, and a continuous electric desalting subunit with an ion exchange subunit.
The apparatus of claim 14 wherein said separation unit comprises a reverse osmosis subunit, and wherein said reverse osmosis subunit comprises a one or two stage reverse osmosis apparatus.
The apparatus according to claim 15, wherein said separation unit further comprises a continuous electric desalting subunit, said reverse osmosis subunit and said continuous electric desalting subunit being sequentially connected, wherein said continuous electric desalination The subunit includes one or two stages of continuous electric desalination equipment; or

The separation unit further includes an ion exchange subunit, and the reverse osmosis subunit and the ion exchange subunit are sequentially connected, wherein the ion exchange subunit includes one or more ion exchangers.
The apparatus according to claim 15 or 16, wherein said reverse osmosis apparatus employs a reverse osmosis membrane module or two or more reverse osmosis membrane modules in series, and when two or more reverse osmosis membrane modules are used, the upper one is reversed. The concentrate outlet of the permeable membrane module is connected to the inlet of the next reverse osmosis membrane module.
The apparatus according to claim 15 or 16, wherein said reverse osmosis subunit comprises a primary reverse osmosis device, and said concentrate outlet of said reverse osmosis device is divided into two branches via a pipe, a branch and said The inlet of the reverse osmosis device is connected, and the other branch is connected to the inlet of the chemical precipitation unit; or

The reverse osmosis subunit comprises a two-stage reverse osmosis device, wherein the concentrate outlet of the first stage reverse osmosis device is divided into two branches via a pipeline, one branch is connected to the inlet of the first stage reverse osmosis device, and the other branch is connected The road is connected to the inlet of the chemical precipitation unit.
The apparatus according to claim 15 or 16, wherein said reverse osmosis subunit comprises a two-stage reverse osmosis apparatus, wherein a purge liquid outlet of the first stage reverse osmosis apparatus is connected to an inlet of the second stage reverse osmosis apparatus, The concentrate outlet of the secondary reverse osmosis apparatus is connected to the inlet of the first stage reverse osmosis apparatus, and the concentrate outlet of the first stage reverse osmosis apparatus is connected to the inlet of the chemical precipitation unit.
The apparatus according to claim 16, wherein said continuous electric desalination subunit comprises a two-stage continuous electric desalination apparatus, wherein said purification liquid outlet of said reverse osmosis subunit is continuously deionized with said first stage The inlet of the device is connected, the outlet of the purification liquid of the first-stage continuous electric desalination device is connected with the inlet of the second-stage continuous electric desalination device, and the purification liquid outlet of the second-stage continuous electric desalination device The drain unit is connected, and the concentrate outlet of the first stage continuous electric desalination apparatus and the concentrate outlet of the second stage continuous electric desalination apparatus are respectively connected to the inlet of the reverse osmosis subunit.
The apparatus according to claim 20, wherein said purification liquid outlet of said first-stage continuous electric desalination apparatus is connected to an inlet of said second-stage continuous electric desalination apparatus via an intermediate water tank, said intermediate water tank and activator The boxes are connected.
The apparatus according to claim 12, wherein the apparatus further comprises a pre-processing unit connected to the inlet of the separation unit for removing one of oil, colloid, and particulate matter in the radioactive waste liquid. Above and/or, adjust the pH.