Method and system for pre-treatment of radioactive waste liquid for bathing

Abstract

The application discloses a method and system for pre-treating bathing radioactive waste liquid, which comprises the following steps: 1) adjusting the pH value of the bathing radioactive waste liquid to a first preset pH value, mixing the bathing radioactive waste liquid with hydrogen peroxide, and then feeding the mixture into a Fenton oxidation unit filled with Fenton catalyst, so that organic matters in the bathing radioactive waste liquid are oxidized and decomposed; 2) adjusting the pH value of the water after the oxidation and decomposition to a second preset pH value, and then performing flocculation and precipitation, and then performing solid-liquid separation to obtain supernatant; 3) performing ultrafiltration on the supernatant to obtain ultrafiltration water; and 4) removing organic matters from the ultrafiltration water by reverse osmosis, and performing separation and concentration to obtain reverse osmosis water and reverse osmosis concentrated water respectively. The method has a high removal rate of organic matters, and the total removal rate of COD in the system can reach more than 98%; and the Fenton catalyst is used to effectively reduce the amount of secondary radioactive waste.

Description

Technical Field

[0001] This invention belongs to the field of waste liquid treatment technology, specifically relating to a method and system for pretreatment of radioactive waste liquid from bathing. Background Technology

[0002] Nuclear facilities generate various types of radioactive waste during operation, which require effective treatment to protect the surrounding environment and residents. Commonly used radioactive waste treatment technologies include evaporation, ion exchange, and membrane treatment. Appropriate pretreatment is usually necessary before radioactive waste treatment to ensure the stable and safe operation of subsequent processes and equipment. This is because radioactive waste contains not only radionuclides but also non-radioactive substances such as solid particles, organic matter, and inorganic salts. The presence of these non-radioactive substances often affects the effectiveness and safety of radioactive waste treatment; therefore, these non-radioactive substances should be removed as much as possible before radionuclide treatment.

[0003] Radioactive waste liquid from bathing facilities is a special type of radioactive waste liquid generated by nuclear facilities. It consists of laundry water and shower water that exceeds the standards. In addition to radioactive nuclides, it also contains organic matter such as surfactants. Organic matter must be removed from bathing waste liquid before radioactive nuclides are removed; otherwise, it will adversely affect subsequent evaporation, ion exchange, or membrane treatment, and may even affect their normal operation.

[0004] Common pretreatment methods for this type of wastewater include ozone oxidation (O3 oxidation), ultraviolet (UV) treatment, Fenton oxidation, or a combination of these methods. Ozone oxidation can achieve a COD removal rate of about 50% without generating secondary waste, but it requires good ventilation to remove residual ozone and generated carbon dioxide. UV treatment often needs to be combined with ozone oxidation or other oxidation methods. The UV / ozone process is highly effective in water treatment, but the process is complex, with high initial investment and subsequent operating costs. The combined ozone / UV / hydrogen peroxide process has shown outstanding capabilities in treating recalcitrant organic pollutants. However, the practical application of this process also faces a series of challenges, such as the complex operation of ozone generation, the low utilization rate of oxidants O3 / H2O2, and the need for post-treatment processes (such as activated carbon adsorption) to reduce secondary pollution caused by residual O3. Fenton oxidation is a powerful and low-cost oxidation method widely used for the removal of organic matter from wastewater. The traditional Fenton oxidation process uses ferrous salts and hydrogen peroxide under acidic conditions. The addition of ferrous salts produces a large amount of iron sludge, which increases the cost of subsequent secondary waste treatment. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to address the above-mentioned deficiencies in the prior art by providing a method and system for pretreatment of radioactive waste liquid from bathing, which has a high removal rate of organic matter in the radioactive waste liquid from bathing.

[0006] The technical solution adopted to solve the technical problem of this invention is to provide a method for pretreatment of radioactive waste liquid from bathing, comprising the following steps:

[0007] 1) Adjust the pH value of the radioactive waste liquid from the bath to the first preset pH value, then mix it with hydrogen peroxide, and then pass it into the Fenton oxidation unit. The Fenton oxidation unit is filled with Fenton catalyst, and the organic matter in the radioactive waste liquid from the bath is oxidized and decomposed.

[0008] 2) Adjust the pH of the effluent after oxidation and decomposition to the second preset pH value, then perform flocculation and sedimentation, and then perform solid-liquid separation to obtain the supernatant;

[0009] 3) The supernatant is subjected to ultrafiltration to obtain ultrafiltration permeate;

[0010] 4) The ultrafiltration permeate is subjected to reverse osmosis to remove organic matter, and then separated and concentrated to obtain reverse osmosis permeate and reverse osmosis concentrate, respectively.

[0011] Preferably, the Fenton catalyst contains at least one of ferric sulfate, ferric sulfate hydrate, ferrous sulfate, and ferrous sulfate hydrate.

[0012] Preferably, the Fenton catalyst is a Fenton catalytic oxidation packing material, which is a solid spherical catalyst with a particle size of 1-3 mm.

[0013] Preferably, the radioactive waste liquid from bathing includes: strontium ions, cesium ions, calcium ions, magnesium ions, surfactants, and detergent organic matter.

[0014] Preferably, in step 1), after adjusting the pH value to the first preset pH value, the radioactive waste liquid from the bath is acidic.

[0015] In step 2), after adjusting the pH value to the second preset pH value, the radioactive waste liquid from the bath is neutral or alkaline.

[0016] Preferably, the first preset pH value in step 1) is 1 to 6;

[0017] The dosage of hydrogen peroxide relative to radioactive waste liquid from bathing is 0.5–3.0 mL / L;

[0018] The ratio of the Fenton catalyst's bulk volume to the volume of radioactive waste liquid from the bath is 1:1 to 1:4.

[0019] The oxidation reaction temperature of organic matter in radioactive wastewater from bathing is 15–40℃, and the reaction time is 2–6 hours.

[0020] Preferably, the second preset pH value in step 2) is 7 to 9;

[0021] When performing flocculation and sedimentation, add a flocculant polyalumina (PAC) solution with a mass concentration of 5% to 10% and a dosage of 100 to 300 mg / L; add a coagulant aid polyacrylamide (PAM) solution with a mass concentration of 0.1% to 0.2% and a dosage of 0.3 to 3 mg / L.

[0022] Preferably, the reverse osmosis is a 1-3 stage reverse osmosis.

[0023] The present invention also provides a system for the above-described method for pretreatment of radioactive waste liquid from bathing, comprising:

[0024] The reaction device is used to introduce radioactive waste liquid from bathing, adjust the pH value of the radioactive waste liquid to the first preset pH value, mix it with hydrogen peroxide, and then introduce it into the Fenton catalytic oxidation unit. The Fenton catalytic oxidation unit is filled with Fenton catalyst, and the organic matter in the radioactive waste liquid from bathing is oxidized and decomposed.

[0025] The separation device is connected to the reaction unit. The separation unit is used to adjust the pH value of the effluent after oxidation and decomposition to a second preset pH value, then perform flocculation and sedimentation, and then perform solid-liquid separation to obtain the supernatant.

[0026] An ultrafiltration unit is connected to a separation unit. The ultrafiltration unit is used to ultrafilter the supernatant to obtain ultrafiltration permeate.

[0027] The reverse osmosis unit is connected to the ultrafiltration unit. The reverse osmosis unit is used to remove organic matter from the ultrafiltration permeate through reverse osmosis, and then separate and concentrate it to obtain reverse osmosis permeate and reverse osmosis concentrate, respectively.

[0028] Preferably, the reaction apparatus includes:

[0029] The first pH adjustment unit is used to adjust the pH value of the radioactive waste liquid from bathing to a first preset pH value.

[0030] The hydrogen peroxide unit is connected to the first pH adjustment unit. The hydrogen peroxide unit is used to mix the bath radioactive waste liquid with the first preset pH value with hydrogen peroxide.

[0031] The Fenton oxidation unit is connected to the hydrogen peroxide unit and is filled with Fenton catalyst. In the Fenton oxidation unit, the organic matter in the bath radioactive waste liquid is oxidized and decomposed.

[0032] Preferably, the separation device includes:

[0033] The second pH adjustment unit is connected to the reaction unit and is used to adjust the pH of the effluent after oxidation and decomposition to a second preset pH value.

[0034] The sedimentation unit is connected to the second pH adjustment unit. The sedimentation unit is used to flocculate and precipitate the effluent after oxidation and decomposition at the second preset pH value.

[0035] The solid-liquid separator is connected to the sedimentation unit and is used for solid-liquid separation to obtain supernatant.

[0036] Preferably, the ultrafiltration device includes:

[0037] The ultrafiltration water supply tank is connected to the separation device and is used to store the supernatant.

[0038] The ultrafiltration membrane module is connected to the ultrafiltration water supply tank. The ultrafiltration membrane module is used for ultrafiltration to obtain ultrafiltration permeate and ultrafiltration wastewater. The ultrafiltration wastewater is returned to the ultrafiltration water supply tank.

[0039] The ultrafiltration permeate tank is connected to the ultrafiltration membrane module, and the ultrafiltration permeate flows into the ultrafiltration permeate tank.

[0040] Preferably, the ultrafiltration device further includes a multi-media filter and a precision filter connected in sequence on the pipeline between the ultrafiltration water supply tank and the ultrafiltration membrane module. The supernatant flows through the multi-media filter and the precision filter in sequence to remove colloids, suspended solid particles and large molecular particles from the wastewater.

[0041] Preferably, the nominal pore size of the ultrafiltration membrane in the ultrafiltration membrane module is in the range of 0.03 μm to 0.1 μm.

[0042] Preferably, the reverse osmosis unit includes:

[0043] The first-stage reverse osmosis membrane module is connected to the ultrafiltration unit. The ultrafiltration permeate enters the first-stage reverse osmosis membrane module, and the permeate from the first-stage reverse osmosis membrane module enters the reverse osmosis permeate tank.

[0044] The second-stage reverse osmosis membrane module is connected to the first-stage reverse osmosis membrane module. The concentrate from the first-stage reverse osmosis membrane module enters the second-stage reverse osmosis membrane module, and the permeate from the second-stage reverse osmosis membrane module enters the reverse osmosis permeate tank.

[0045] The third-stage reverse osmosis membrane module is connected to the second-stage reverse osmosis membrane module. The concentrate from the second-stage reverse osmosis membrane module enters the third-stage reverse osmosis membrane module, the permeate from the third-stage reverse osmosis membrane module enters the reverse osmosis permeate tank, and the concentrate from the third-stage reverse osmosis membrane module enters the reverse osmosis concentrate tank.

[0046] The reverse osmosis product water tank is connected to the first-stage reverse osmosis membrane module, the second-stage reverse osmosis membrane module, and the third-stage reverse osmosis membrane module, respectively.

[0047] The reverse osmosis concentrate tank is connected to the third-stage reverse osmosis membrane module.

[0048] Preferably, the system used in the method for pretreating radioactive waste liquid from bathing is...

[0049] The first-stage reverse osmosis membrane module is a three-section type, with the ratio of the number of membrane shells in each section being 2:1:1;

[0050] The second-stage reverse osmosis membrane module is a two-section type, with the ratio of the number of membrane housings in the two sections being 1:1.

[0051] The third-stage reverse osmosis membrane module is a two-stage type, with the ratio of the number of membrane housings in the two stages being 1:1.

[0052] Preferably, the system used in the method for pretreatment of radioactive waste liquid from bathing further includes:

[0053] The discharge facility or deep purification device is connected to the reverse osmosis permeate tank, and the reverse osmosis permeate enters the discharge facility for discharge or the deep purification device for deep purification.

[0054] An evaporation concentration unit or a cement curing unit is connected to a reverse osmosis concentrate tank. The reverse osmosis concentrate enters the evaporation concentration unit for evaporation concentration or the cement curing unit for cement curing.

[0055] The method and system for pretreatment of radioactive wastewater from bathing facilities in this invention employs Fenton catalytic oxidation, ultrafiltration, and reverse osmosis technologies to treat organic matter in the wastewater. It achieves a high organic matter removal rate, with a total COD removal rate exceeding 98%. The use of a Fenton catalyst instead of the ferrous salts used in traditional Fenton oxidation effectively reduces secondary radioactive waste by over 90%. The method achieves a total cesium removal rate of approximately 95% and a strontium removal rate of approximately 98%. Reverse osmosis in this method concentrates salts and radionuclides by approximately 10 times, significantly reducing the processing capacity of subsequent concentration equipment. The method provided by this invention features a simple and convenient process, high pollutant removal rate, safety and reliability, reduced secondary waste generation, and simple equipment maintenance, making it particularly suitable for treating radioactive wastewater from bathing facilities. Attached Figure Description

[0056] Figure 1 This is a flowchart of the method for pretreatment of radioactive waste liquid used in bathing, as described in Embodiment 2 of the present invention. Detailed Implementation

[0057] To enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0058] The embodiments of this patent are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this patent, and should not be construed as limiting this patent.

[0059] Example 1

[0060] This embodiment provides a method for pretreatment of radioactive waste liquid from bathing, including the following steps:

[0061] 1) Adjust the pH value of the radioactive waste liquid from the bath to the first preset pH value, then mix it with hydrogen peroxide, and then pass it into the Fenton oxidation unit. The Fenton oxidation unit is filled with Fenton catalyst, and the organic matter in the radioactive waste liquid from the bath is oxidized and decomposed.

[0062] 2) Adjust the pH of the effluent after oxidation and decomposition to the second preset pH value, then perform flocculation and sedimentation, and then perform solid-liquid separation to obtain the supernatant;

[0063] 3) The supernatant is subjected to ultrafiltration to obtain ultrafiltration permeate;

[0064] 4) The ultrafiltration permeate is subjected to reverse osmosis to remove organic matter, and then separated and concentrated to obtain reverse osmosis permeate and reverse osmosis concentrate, respectively.

[0065] This embodiment also provides a system used in the above-described method for pretreatment of radioactive waste liquid from bathing, comprising:

[0066] The reaction device is used to introduce radioactive waste liquid from bathing, adjust the pH value of the radioactive waste liquid to the first preset pH value, mix it with hydrogen peroxide, and then introduce it into the Fenton oxidation unit. The Fenton oxidation unit is filled with Fenton catalyst, and the organic matter in the radioactive waste liquid from bathing is oxidized and decomposed.

[0067] The separation device is connected to the reaction unit. The separation unit is used to adjust the pH value of the effluent after oxidation and decomposition to a second preset pH value, then perform flocculation and sedimentation, and then perform solid-liquid separation to obtain the supernatant.

[0068] An ultrafiltration unit is connected to a separation unit. The ultrafiltration unit is used to ultrafilter the supernatant to obtain ultrafiltration permeate.

[0069] The reverse osmosis unit is connected to the ultrafiltration unit. The reverse osmosis unit is used to remove organic matter from the ultrafiltration permeate through reverse osmosis, and then separate and concentrate it to obtain reverse osmosis permeate and reverse osmosis concentrate, respectively.

[0070] The method and system for pretreatment of radioactive wastewater from bathing facilities in this embodiment employs Fenton catalytic oxidation, ultrafiltration, and reverse osmosis technologies to treat organic matter in the wastewater. It achieves a high organic matter removal rate, with a total COD removal rate exceeding 98%. The use of a Fenton catalyst instead of the ferrous salts used in traditional Fenton oxidation effectively reduces secondary radioactive waste by over 90%. The method achieves a total cesium removal rate of approximately 95% and a strontium removal rate of approximately 98%. Reverse osmosis in this method concentrates salts and radionuclides by approximately 10 times, significantly reducing the processing capacity of subsequent concentration equipment. The method provided in this embodiment features a simple and convenient process, high pollutant removal rate, safety and reliability, reduced secondary waste generation, and simple equipment maintenance, making it particularly suitable for treating radioactive wastewater from bathing facilities.

[0071] Example 2

[0072] This embodiment provides a system for the pretreatment of radioactive waste liquid from bathing, including:

[0073] The reaction device is used to introduce radioactive waste liquid from bathing, adjust the pH value of the radioactive waste liquid to the first preset pH value, mix it with hydrogen peroxide, and then introduce it into the Fenton oxidation unit. The Fenton oxidation unit is filled with Fenton catalyst, and the organic matter in the radioactive waste liquid from bathing is oxidized and decomposed.

[0074] The separation device is connected to the reaction unit. The separation unit is used to adjust the pH value of the effluent after oxidation and decomposition to a second preset pH value, then perform flocculation and sedimentation, and then perform solid-liquid separation to obtain the supernatant.

[0075] An ultrafiltration unit is connected to a separation unit. The ultrafiltration unit is used to ultrafilter the supernatant to obtain ultrafiltration permeate.

[0076] The reverse osmosis unit is connected to the ultrafiltration unit. The reverse osmosis unit is used to remove organic matter from the ultrafiltration permeate through reverse osmosis, and then separate and concentrate it to obtain reverse osmosis permeate and reverse osmosis concentrate, respectively.

[0077] Preferably, the reaction apparatus includes:

[0078] The first pH adjustment unit is used to adjust the pH value of the radioactive waste liquid from bathing to a first preset pH value.

[0079] The hydrogen peroxide unit is connected to the first pH adjustment unit. The hydrogen peroxide unit is used to mix the bath radioactive waste liquid with the first preset pH value with hydrogen peroxide.

[0080] The Fenton oxidation unit is connected to the hydrogen peroxide unit and is filled with Fenton catalyst. In the Fenton oxidation unit, the organic matter in the bath radioactive waste liquid is oxidized and decomposed.

[0081] Preferably, the separation device includes:

[0082] The second pH adjustment unit is connected to the reaction unit and is used to adjust the pH of the effluent after oxidation and decomposition to a second preset pH value.

[0083] The sedimentation unit is connected to the second pH adjustment unit. The sedimentation unit is used to flocculate and precipitate the effluent after oxidation and decomposition at the second preset pH value.

[0084] The solid-liquid separator is connected to the sedimentation unit and is used for solid-liquid separation to obtain supernatant.

[0085] Preferably, the ultrafiltration device includes:

[0086] The ultrafiltration water supply tank is connected to the separation device and is used to store the supernatant.

[0087] The ultrafiltration membrane module is connected to the ultrafiltration water supply tank. The ultrafiltration membrane module is used for ultrafiltration to obtain ultrafiltration permeate and ultrafiltration wastewater. The ultrafiltration wastewater is returned to the ultrafiltration water supply tank.

[0088] The ultrafiltration permeate tank is connected to the ultrafiltration membrane module, and the ultrafiltration permeate flows into the ultrafiltration permeate tank.

[0089] Preferably, the ultrafiltration device further includes a multi-media filter and a precision filter connected in sequence on the pipeline between the ultrafiltration water supply tank and the ultrafiltration membrane module. The supernatant flows through the multi-media filter and the precision filter in sequence to remove colloids, suspended solid particles and large molecular particles from the wastewater.

[0090] Preferably, the nominal pore size of the ultrafiltration membrane in the ultrafiltration membrane module is in the range of 0.03 μm to 0.1 μm. The ultrafiltration membrane is a hollow fiber membrane made of PVDF.

[0091] Preferably, the reverse osmosis unit includes:

[0092] The first-stage reverse osmosis membrane module is connected to the ultrafiltration unit. The ultrafiltration permeate enters the first-stage reverse osmosis membrane module, and the permeate from the first-stage reverse osmosis membrane module enters the reverse osmosis permeate tank.

[0093] The second-stage reverse osmosis membrane module is connected to the first-stage reverse osmosis membrane module. The concentrate from the first-stage reverse osmosis membrane module enters the second-stage reverse osmosis membrane module, and the permeate from the second-stage reverse osmosis membrane module enters the reverse osmosis permeate tank.

[0094] The third-stage reverse osmosis membrane module is connected to the second-stage reverse osmosis membrane module. The concentrate from the second-stage reverse osmosis membrane module enters the third-stage reverse osmosis membrane module, the permeate from the third-stage reverse osmosis membrane module enters the reverse osmosis permeate tank, and the concentrate from the third-stage reverse osmosis membrane module enters the reverse osmosis concentrate tank.

[0095] The reverse osmosis product water tank is connected to the first-stage reverse osmosis membrane module, the second-stage reverse osmosis membrane module, and the third-stage reverse osmosis membrane module, respectively.

[0096] The reverse osmosis concentrate tank is connected to the third-stage reverse osmosis membrane module.

[0097] Specifically, the system used in this embodiment for the pretreatment of radioactive waste liquid from bathing also includes: a reverse osmosis booster pump, a security filter, a first-stage booster pump, a second-stage booster pump, and a third-stage high-pressure pump.

[0098] A reverse osmosis booster pump, a security filter, and a first-stage booster pump are sequentially installed on the connecting pipeline between the ultrafiltration unit and the first-stage reverse osmosis membrane module.

[0099] The second-stage booster pump is installed on the connecting pipeline between the first-stage reverse osmosis membrane module and the second-stage reverse osmosis membrane module.

[0100] The third-stage booster pump is installed on the connecting pipeline between the second-stage and third-stage reverse osmosis membrane modules.

[0101] Specifically, in this embodiment, the ultrafiltration permeate is boosted by a reverse osmosis booster pump and enters a security filter. The effluent from the security filter then enters the first-stage reverse osmosis membrane module via a first-stage booster pump. The permeate from the first-stage reverse osmosis membrane module enters the reverse osmosis permeate tank. The concentrate from the first-stage reverse osmosis membrane module enters the second-stage reverse osmosis membrane module via a second-stage booster pump. The permeate from the second-stage reverse osmosis membrane module enters the reverse osmosis permeate tank. The concentrate from the second-stage reverse osmosis membrane module is pressurized by a third-stage high-pressure pump and enters the third-stage reverse osmosis membrane module. The permeate from the third-stage reverse osmosis membrane module enters the reverse osmosis permeate tank, and the concentrate from the third-stage reverse osmosis membrane module enters the reverse osmosis concentrate tank. The security filter is used to remove particulate impurities from the water and protect the reverse osmosis membrane modules in subsequent processes. The reverse osmosis membrane modules are used to further remove organic matter from the radioactive wastewater from bathing, and simultaneously separate and concentrate radioactive nuclides.

[0102] Preferably, the system used in the method for pretreating radioactive waste liquid from bathing is...

[0103] The first-stage reverse osmosis membrane module is a three-section type, with the ratio of the number of membrane shells in each section being 2:1:1;

[0104] The second-stage reverse osmosis membrane module is a two-section type, with the ratio of the number of membrane housings in the two sections being 1:1.

[0105] The third-stage reverse osmosis membrane module is a two-stage type, with the ratio of the number of membrane housings in the two stages being 1:1.

[0106] Preferably, the system used in the method for pretreatment of radioactive waste liquid from bathing further includes:

[0107] The discharge facility or deep purification device is connected to the reverse osmosis permeate tank, and the reverse osmosis permeate enters the discharge facility for discharge or the deep purification device for deep purification.

[0108] An evaporation concentration unit or a cement curing unit is connected to a reverse osmosis concentrate tank. The reverse osmosis concentrate enters the evaporation concentration unit for evaporation concentration or the cement curing unit for cement curing.

[0109] like Figure 1 As shown, this embodiment provides a method for using the above-described system for pretreatment of radioactive waste liquid from bathing, comprising the following steps:

[0110] 1) The radioactive waste liquid from bathing is collected in the waste liquid receiving tank, sampled and tested, and then sent to the first pH adjustment unit to adjust the pH of the radioactive waste liquid to the first preset pH value. After the pH value is adjusted, it flows by gravity into the hydrogen peroxide unit to mix with hydrogen peroxide. After the radioactive waste liquid from bathing is fully mixed with hydrogen peroxide, it enters the Fenton oxidation unit. The Fenton oxidation unit is filled with Fenton catalyst. In the Fenton oxidation unit, the organic matter in the radioactive waste liquid from bathing is fully oxidized and decomposed.

[0111] 2) The effluent after oxidation and decomposition enters the second pH adjustment unit, and the pH value is adjusted to the second preset pH value. After the pH value is adjusted, it enters the sedimentation unit for flocculation and sedimentation, and then solid-liquid separation is performed to obtain the supernatant.

[0112] 3) The supernatant enters the ultrafiltration water supply tank. The water in the ultrafiltration water supply tank is filtered by a multi-media filter and a precision filter to initially remove colloids, suspended solid particles and large molecular particles from the wastewater. Then it enters the ultrafiltration membrane module. The ultrafiltration permeate enters the ultrafiltration permeate tank. The ultrafiltration crossflow water is returned to the ultrafiltration water supply tank.

[0113] 4) Ultrafiltration permeate is boosted by a reverse osmosis booster pump and enters a security filter. The effluent from the security filter is then boosted by a first-stage booster pump and enters the first-stage reverse osmosis membrane module. The permeate from the first-stage reverse osmosis membrane module enters the reverse osmosis permeate tank. The concentrate from the first-stage reverse osmosis membrane module is boosted by a second-stage booster pump and enters the second-stage reverse osmosis membrane module. The permeate from the second-stage reverse osmosis membrane module enters the reverse osmosis permeate tank. The concentrate from the second-stage reverse osmosis membrane module is pressurized by a third-stage high-pressure pump and enters the third-stage reverse osmosis membrane module. The permeate from the third-stage reverse osmosis membrane module enters the reverse osmosis permeate tank, and the concentrate from the third-stage reverse osmosis membrane module enters the reverse osmosis concentrate tank. The security filter is used to remove particulate impurities from the water and protect the reverse osmosis membrane modules in subsequent processes. The reverse osmosis membrane modules are used to further remove organic matter from radioactive wastewater from bathing facilities and to separate and concentrate radioactive nuclides.

[0114] Preferably, the Fenton catalyst contains at least one of ferric sulfate, ferric sulfate hydrate, ferrous sulfate, and ferrous sulfate hydrate.

[0115] Specifically, the Fenton catalyst in this embodiment contains ferric sulfate.

[0116] Preferably, the Fenton catalyst is a Fenton catalytic oxidation packing material, which is a solid spherical catalyst with a particle size of 1-3 mm.

[0117] Preferably, the radioactive waste liquid from bathing includes: strontium ions, cesium ions, calcium ions, magnesium ions, surfactants, and detergent organic matter.

[0118] Preferably, in step 1), after adjusting the pH value to the first preset pH value, the radioactive waste liquid from the bath is acidic.

[0119] In step 2), after adjusting the pH value to the second preset pH value, the radioactive waste liquid from the bath is neutral or alkaline.

[0120] Preferably, the first preset pH value in step 1) is 1 to 6;

[0121] The dosage of hydrogen peroxide relative to radioactive waste liquid from bathing is 0.5–3.0 mL / L;

[0122] The ratio of the Fenton catalyst's bulk volume to the volume of radioactive waste liquid from the bath is 1:1 to 1:4.

[0123] The oxidation reaction temperature of organic matter in radioactive wastewater from bathing is 15–40℃, and the reaction time is 2–6 hours.

[0124] Preferably, the second preset pH value in step 2) is 7 to 9;

[0125] When performing flocculation and sedimentation, add polyalumina (PAC) solution with a mass concentration of 5% to 10% and a dosage of 100 to 300 mg / L; add polyacrylamide (PAM) solution with a mass concentration of 0.1% to 0.2% and a dosage of 0.3 to 3 mg / L.

[0126] Preferably, the reverse osmosis is a 1-3 stage reverse osmosis.

[0127] This embodiment describes a system designed and manufactured for the pretreatment of radioactive waste liquid from bathing facilities, specifically for processing simulated radioactive waste liquid from bathing facilities. The system's designed processing capacity is 2m³. 3 / h, using isotopes to simulate radioactive waste liquid, simulating Cs in bath radioactive waste liquid. + Concentration 910 μg / L, Sr 2+ The concentration is 170 μg / L.

[0128] Nuclide Cs + and Sr 2+ The concentration was determined using ICP-MS inductively coupled plasma mass spectrometry.

[0129] When preparing simulated radioactive wastewater for bathing, surfactants and other organic substances from the simulated wastewater, such as laundry detergent, washing liquid, or shower gel, are used to fully dissolve these substances in tap water. The COD concentration in the simulated radioactive wastewater for bathing is 592–611 mg / L.

[0130] Specifically, in this embodiment, the simulated radioactive waste liquid from bathing is prepared in a waste liquid receiving tank, passes through a first pH adjustment unit to adjust the pH to 1, and then flows by gravity into a hydrogen peroxide unit at a dosage of 0.5 ml / L. After thorough mixing, it enters the Fenton oxidation unit. The Fenton oxidation unit is filled with Fenton catalyst, and the ratio of the Fenton catalyst volume to the original water volume is 1:1. In the Fenton oxidation unit, the oxidation reaction temperature is 15°C, and the reaction time is 2 hours, during which the organic matter in the waste liquid is fully oxidized and decomposed.

[0131] The effluent after oxidation and decomposition enters the second pH adjustment unit. After the pH is adjusted to 7, it enters the sedimentation unit for flocculation and sedimentation. A flocculant solution of polyalumina (PAC) is added at a concentration of 5% and a dosage of 100 mg / L; a coagulant aid solution of polyacrylamide (PAM) is added at a concentration of 0.2% and a dosage of 0.3 mg / L.

[0132] The simulated radioactive wastewater from bathing was treated with Fenton oxidation, and after flocculation and sedimentation, the supernatant was collected and measured. The COD removal rate in the simulated radioactive wastewater reached 72%. The concentration of strontium and cesium nuclides remained unchanged.

[0133] After solid-liquid separation, the supernatant enters the ultrafiltration water supply tank.

[0134] Water stored in the ultrafiltration supply tank passes through a multi-media filter and a precision filter to remove colloids, suspended solids, and large molecular particles from the wastewater. It then enters the ultrafiltration membrane module, which uses a hollow fiber membrane made of PVDF with a nominal pore size of 0.03μm to 0.1μm. After ultrafiltration purification, the ultrafiltration permeate enters the ultrafiltration permeate tank, while the ultrafiltration outflow is returned to the ultrafiltration supply tank.

[0135] Measurements show that ultrafiltration removes approximately 15% of COD.

[0136] Ultrafiltration permeate is boosted by a reverse osmosis booster pump and enters a security filter. The effluent from the security filter is then boosted by a first-stage booster pump and enters the first-stage reverse osmosis membrane module. The permeate from the first-stage reverse osmosis membrane module enters the reverse osmosis permeate tank. The concentrate from the first-stage reverse osmosis membrane module is boosted by a second-stage booster pump and enters the second-stage reverse osmosis membrane module. The permeate from the second-stage reverse osmosis membrane module enters the reverse osmosis permeate tank. The concentrate from the second-stage reverse osmosis membrane module is pressurized by a third-stage high-pressure pump and enters the third-stage reverse osmosis membrane module. The permeate from the third-stage reverse osmosis membrane module enters the reverse osmosis permeate tank, and the concentrate from the third-stage reverse osmosis membrane module enters the reverse osmosis concentrate tank. The security filter is used to remove particulate impurities from the water, protecting the reverse osmosis membrane modules in subsequent processes. The reverse osmosis membrane modules are used to further remove organic matter from radioactive wastewater from bathing facilities, while simultaneously separating and concentrating radioactive nuclides. The first-stage reverse osmosis membrane module is a three-stage module with a membrane housing ratio of 2:1:1; the second-stage reverse osmosis membrane module is a two-stage module with a membrane housing ratio of 1:1; and the third-stage reverse osmosis membrane module is a two-stage module with a membrane housing ratio of 1:1.

[0137] Measurements show that the reverse osmosis system can remove up to 95.6% of the COD from individual cells. The total product water recovery rate is around 90%.

[0138] The first-stage reverse osmosis membrane in the first-stage reverse osmosis membrane module has removal rates of 98.31% and 98.32% for cesium and strontium, respectively. The second-stage reverse osmosis membrane in the second-stage reverse osmosis membrane module has removal rates of 98.05% and 99.56% for cesium and strontium, respectively. The third-stage reverse osmosis membrane in the third-stage reverse osmosis membrane module has removal rates of 95.93% and 99.28% for cesium and strontium, respectively.

[0139] The method and system for pretreatment of radioactive wastewater from bathing facilities in this embodiment employs Fenton catalytic oxidation, ultrafiltration, and reverse osmosis technologies to treat organic matter in the wastewater. It achieves a high organic matter removal rate, with a total COD removal rate exceeding 98%. The use of a Fenton catalyst instead of the traditional ferrous salts used in Fenton oxidation effectively reduces secondary radioactive waste by over 90%. The method achieves a total cesium removal rate of approximately 95% and a strontium removal rate of approximately 98%. Reverse osmosis in this method concentrates salts and radionuclides by approximately 10 times, significantly reducing the processing capacity of subsequent concentration equipment. The method provided in this embodiment features a simple and convenient process, high pollutant removal rate, safety and reliability, reduced secondary waste generation, and simple equipment maintenance, making it more suitable for treating radioactive wastewater from bathing facilities. The use of ultrafiltration and reverse osmosis membrane modules further removes organic pollutants and retains radionuclides, significantly reducing the amount of subsequent radioactive wastewater requiring treatment.

[0140] Example 3

[0141] This embodiment describes a system designed and manufactured for the pretreatment of radioactive waste liquid from bathing facilities, specifically for processing simulated radioactive waste liquid from bathing facilities. The system's designed processing capacity is 2m³. 3 / h, using isotopes to simulate radioactive waste liquid, simulating Cs in bath radioactive waste liquid. + Concentration 910 μg / L, Sr 2+ The concentration is 170 μg / L.

[0142] Nuclide Cs + and Sr 2+ The concentration was determined using ICP-MS inductively coupled plasma mass spectrometry.

[0143] When preparing simulated radioactive wastewater for bathing, surfactants and other organic substances from the simulated wastewater, such as laundry detergent, washing liquid, or shower gel, are used to fully dissolve these substances in tap water. The COD concentration in the simulated radioactive wastewater for bathing is 592–611 mg / L.

[0144] This embodiment provides a method for pretreating radioactive waste liquid from bathing using the system described in Embodiment 2. The difference between this method and the method in Embodiment 2 is as follows:

[0145] Specifically, in this embodiment, the simulated radioactive waste liquid from bathing is prepared in a waste liquid receiving tank, passes through a first pH adjustment unit to adjust the pH to 3, and then flows by gravity into a hydrogen peroxide unit. The hydrogen peroxide dosage is 1 ml / L. After thorough mixing, it enters the Fenton oxidation unit. The Fenton oxidation unit is filled with a Fenton catalyst containing ferric sulfate and ferric sulfate hydrate (mass ratio 1:1), and the ratio of the Fenton catalyst volume to the original water volume is 1:3. In the Fenton oxidation unit, the oxidation reaction temperature is 30°C, and the reaction time is 4 hours, during which the organic matter in the waste liquid is fully oxidized and decomposed.

[0146] The effluent after oxidation and decomposition enters the second pH adjustment unit. After adjusting the pH to 8, it enters the sedimentation unit for flocculation and sedimentation. A flocculant solution of polyalumina (PAC) with a PAC mass concentration of 7% and a dosage of 200 mg / L is added; a coagulant aid solution of polyacrylamide (PAM) with a PAM mass concentration of 0.15% and a dosage of 3 mg / L is also added.

[0147] The simulated radioactive wastewater from the bathing facility was treated with Fenton oxidation, and after flocculation and sedimentation, the supernatant was collected and measured. The COD removal rate in the simulated radioactive wastewater reached 84%. The concentration of strontium and cesium nuclides remained unchanged.

[0148] After solid-liquid separation, the supernatant enters the ultrafiltration water supply tank.

[0149] Water stored in the ultrafiltration supply tank passes through a multi-media filter and a precision filter to remove colloids, suspended solids, and large molecular particles from the wastewater. It then enters the ultrafiltration membrane module, which uses a hollow fiber membrane made of PVDF with a nominal pore size of 0.1 μm. After ultrafiltration purification, the ultrafiltration permeate enters the ultrafiltration permeate tank, while the ultrafiltration outflow is returned to the ultrafiltration supply tank.

[0150] Measurements show that ultrafiltration removes approximately 20% of COD.

[0151] Ultrafiltration permeate is boosted by a reverse osmosis booster pump and enters a security filter. The effluent from the security filter is then boosted by a first-stage booster pump and enters the first-stage reverse osmosis membrane module. The permeate from the first-stage reverse osmosis membrane module enters the reverse osmosis permeate tank. The concentrate from the first-stage reverse osmosis membrane module is boosted by a second-stage booster pump and enters the second-stage reverse osmosis membrane module. The permeate from the second-stage reverse osmosis membrane module enters the reverse osmosis permeate tank. The concentrate from the second-stage reverse osmosis membrane module is pressurized by a third-stage high-pressure pump and enters the third-stage reverse osmosis membrane module. The permeate from the third-stage reverse osmosis membrane module enters the reverse osmosis permeate tank, and the concentrate from the third-stage reverse osmosis membrane module enters the reverse osmosis concentrate tank. The security filter is used to remove particulate impurities from the water, protecting the reverse osmosis membrane modules in subsequent processes. The reverse osmosis membrane modules are used to further remove organic matter from radioactive wastewater from bathing facilities, while simultaneously separating and concentrating radioactive nuclides. The first-stage reverse osmosis membrane module is a three-stage module with a membrane housing ratio of 2:1:1; the second-stage reverse osmosis membrane module is a two-stage module with a membrane housing ratio of 1:1; and the third-stage reverse osmosis membrane module is a two-stage module with a membrane housing ratio of 1:1.

[0152] Measurements showed that the reverse osmosis system achieved a single-cell COD removal rate of 98.4%, with a total permeate recovery rate of approximately 90%.

[0153] The first-stage reverse osmosis membrane in the first-stage reverse osmosis membrane module has removal rates of 98.41% and 98.42% for cesium and strontium, respectively. The second-stage reverse osmosis membrane in the second-stage reverse osmosis membrane module has removal rates of 98.25% and 99.35% for cesium and strontium, respectively. The third-stage reverse osmosis membrane in the third-stage reverse osmosis membrane module has removal rates of 95.34% and 99.23% for cesium and strontium, respectively.

[0154] The method and system for pretreatment of radioactive wastewater from bathing facilities in this embodiment employs Fenton catalytic oxidation, ultrafiltration, and reverse osmosis technologies to treat organic matter in the wastewater. It achieves a high organic matter removal rate, with a total COD removal rate exceeding 98%. The use of a Fenton catalyst instead of the traditional ferrous salts used in Fenton oxidation effectively reduces secondary radioactive waste by over 90%. The method achieves a total cesium removal rate of approximately 95% and a strontium removal rate of approximately 98%. Reverse osmosis in this method concentrates salts and radionuclides by approximately 10 times, significantly reducing the processing capacity of subsequent concentration equipment. The method provided in this embodiment features a simple and convenient process, high pollutant removal rate, safety and reliability, reduced secondary waste generation, and simple equipment maintenance, making it more suitable for treating radioactive wastewater from bathing facilities. The use of ultrafiltration and reverse osmosis membrane modules further removes organic pollutants and retains radionuclides, significantly reducing the amount of subsequent radioactive wastewater requiring treatment.

[0155] Example 4

[0156] This embodiment describes a system designed and manufactured for the pretreatment of radioactive waste liquid from bathing facilities, specifically for processing simulated radioactive waste liquid from bathing facilities. The system's designed processing capacity is 2m³. 3 / h, using isotopes to simulate radioactive waste liquid, simulating Cs in bath radioactive waste liquid. + Concentration 910 μg / L, Sr 2+ The concentration is 170 μg / L.

[0157] Nuclide Cs + and Sr 2+ The concentration was determined using ICP-MS inductively coupled plasma mass spectrometry.

[0158] When preparing simulated radioactive wastewater for bathing, surfactants and other organic substances from the simulated wastewater, such as laundry detergent, washing liquid, or shower gel, are used to fully dissolve these substances in tap water. The COD concentration in the simulated radioactive wastewater for bathing is 592–611 mg / L.

[0159] This embodiment provides a method for pretreating radioactive waste liquid from bathing using the system described in Embodiment 2. The difference between this method and the method in Embodiment 2 is as follows:

[0160] Specifically, in this embodiment, the simulated radioactive waste liquid from bathing is prepared in a waste liquid receiving tank, passes through a first pH adjustment unit to adjust the pH to 6, and then flows by gravity into a hydrogen peroxide unit at a dosage of 3 ml / L. After thorough mixing, it enters the Fenton oxidation unit. The Fenton oxidation unit is filled with a Fenton catalyst containing ferrous sulfate and ferrous sulfate hydrate (mass ratio 2:1), and the ratio of the Fenton catalyst volume to the original water volume is 1:4. In the Fenton oxidation unit, the oxidation reaction temperature is 40°C, and the reaction time is 6 hours, during which the organic matter in the waste liquid is fully oxidized and decomposed.

[0161] The effluent after oxidation and decomposition enters the second pH adjustment unit. After the pH is adjusted to 9, it enters the sedimentation unit for flocculation and sedimentation. A flocculant solution of polyalumina (PAC) with a mass concentration of 10% and a dosage of 300 mg / L is added; a coagulant aid solution of polyacrylamide (PAM) with a mass concentration of 0.1% and a dosage of 1 mg / L is also added.

[0162] The simulated radioactive wastewater from bathing was treated with Fenton oxidation, and after flocculation and sedimentation, the supernatant was collected and measured. The COD removal rate in the simulated radioactive wastewater reached 78%. The concentration of strontium and cesium nuclides remained unchanged.

[0163] After solid-liquid separation, the supernatant enters the ultrafiltration water supply tank.

[0164] Water stored in the ultrafiltration supply tank passes through a multi-media filter and a precision filter to remove colloids, suspended solids, and large molecular particles from the wastewater. It then enters the ultrafiltration membrane module, which uses a hollow fiber membrane made of PVDF with a nominal pore size of 0.03 μm. After ultrafiltration purification, the ultrafiltration permeate enters the ultrafiltration permeate tank, while the ultrafiltration outflow is returned to the ultrafiltration supply tank.

[0165] Measurements show that ultrafiltration removes approximately 20% of COD.

[0166] Ultrafiltration permeate is boosted by a reverse osmosis booster pump and enters a security filter. The effluent from the security filter is then boosted by a first-stage booster pump and enters the first-stage reverse osmosis membrane module. The permeate from the first-stage reverse osmosis membrane module enters the reverse osmosis permeate tank. The concentrate from the first-stage reverse osmosis membrane module is boosted by a second-stage booster pump and enters the second-stage reverse osmosis membrane module. The permeate from the second-stage reverse osmosis membrane module enters the reverse osmosis permeate tank. The concentrate from the second-stage reverse osmosis membrane module is pressurized by a third-stage high-pressure pump and enters the third-stage reverse osmosis membrane module. The permeate from the third-stage reverse osmosis membrane module enters the reverse osmosis permeate tank, and the concentrate from the third-stage reverse osmosis membrane module enters the reverse osmosis concentrate tank. The security filter is used to remove particulate impurities from the water, protecting the reverse osmosis membrane modules in subsequent processes. The reverse osmosis membrane modules are used to further remove organic matter from radioactive wastewater from bathing facilities, while simultaneously separating and concentrating radioactive nuclides. The first-stage reverse osmosis membrane module is a three-stage module with a membrane housing ratio of 2:1:1; the second-stage reverse osmosis membrane module is a two-stage module with a membrane housing ratio of 1:1; and the third-stage reverse osmosis membrane module is a two-stage module with a membrane housing ratio of 1:1.

[0167] Measurements show that the reverse osmosis system can remove up to 95% of the COD from individual cells. The total product water recovery rate is around 90%.

[0168] The first-stage reverse osmosis membrane in the first-stage reverse osmosis membrane module has removal rates of 98.43% and 98.45% for cesium and strontium, respectively. The second-stage reverse osmosis membrane in the second-stage reverse osmosis membrane module has removal rates of 98.35% and 99.45% for cesium and strontium, respectively. The third-stage reverse osmosis membrane in the third-stage reverse osmosis membrane module has removal rates of 95.54% and 99.33% for cesium and strontium, respectively.

[0169] The method and system for pretreatment of radioactive wastewater from bathing facilities in this embodiment employs Fenton catalytic oxidation, ultrafiltration, and reverse osmosis technologies to treat organic matter in the wastewater. It achieves a high organic matter removal rate, with a total COD removal rate exceeding 98%. The use of a Fenton catalyst instead of the traditional ferrous salts used in Fenton oxidation effectively reduces secondary radioactive waste by over 90%. The method achieves a total cesium removal rate of approximately 95% and a strontium removal rate of approximately 98%. Reverse osmosis in this method concentrates salts and radionuclides by approximately 10 times, significantly reducing the processing capacity of subsequent concentration equipment. The method provided in this embodiment features a simple and convenient process, high pollutant removal rate, safety and reliability, reduced secondary waste generation, and simple equipment maintenance, making it more suitable for treating radioactive wastewater from bathing facilities. The use of ultrafiltration and reverse osmosis membrane modules further removes organic pollutants and retains radionuclides, significantly reducing the amount of subsequent radioactive wastewater requiring treatment.

[0170] It is understood that the above embodiments are merely exemplary implementations used to illustrate the principles of the present invention, and the present invention is not limited thereto. For those skilled in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also considered to be within the scope of protection of the present invention.

Claims

1. A method for the pre-treatment of radioactive waste liquid for bathing, characterized in that, The method comprises the following steps: 1) adjusting the pH value of the bathing radioactive waste liquid to a first preset pH value, the first preset pH value being 1-6, then mixing with hydrogen peroxide, the dosage of hydrogen peroxide relative to the bathing radioactive waste liquid being 0.5-3.0 mL / L, then passing into a Fenton oxidation unit, the Fenton oxidation unit being filled with a Fenton catalyst, the Fenton catalyst containing at least one of iron sulfate, iron sulfate hydrate, ferrous sulfate and ferrous sulfate hydrate, the Fenton catalyst being a Fenton catalytic oxidation filler, which is a solid spherical catalyst with a particle size of 1-3 mm, the organic matter in the bathing radioactive waste liquid being oxidized and decomposed, the ratio of the bulk volume of the Fenton catalyst to the volume of the bathing radioactive waste liquid being 1:1-1:4, the oxidation reaction temperature of the organic matter in the bathing radioactive waste liquid being 15-40 DEG C, and the reaction time being 2-6 h; 2) adjusting the pH value of the water after oxidation and decomposition to a second preset pH value, then performing flocculation and sedimentation, when performing flocculation and sedimentation, adding a flocculant polyaluminum hydroxide solution, the mass concentration of the polyaluminum hydroxide being 5%-10%, and the dosage being 100-300 mg / L; adding a coagulant polyacrylamide solution, the mass concentration of the polyacrylamide being 0.1%-0.2%, and the dosage being 0.3-3 mg / L, then performing solid-liquid separation to obtain supernatant; 3) performing ultrafiltration on the supernatant to obtain ultrafiltration water; 4) removing organic matter from the ultrafiltration water by reverse osmosis, performing separation and concentration to obtain reverse osmosis water and reverse osmosis concentrated water respectively.

2. The method for pre-treatment of radioactive waste liquid for bath according to claim 1, characterized in that, The bathing radioactive waste liquid comprises strontium ions, cesium ions, calcium ions, magnesium ions, a surfactant and washing organic matter.

3. The method for pre-treatment of radioactive waste liquid for bath according to claim 1, characterized in that, In the step 1), after adjusting the pH value to the first preset pH value, the bathing radioactive waste liquid is acidic. In the step 2), after adjusting the pH value to the second preset pH value, the bathing radioactive waste liquid is neutral or alkaline.

4. The method for pre-treatment of radioactive waste liquid for bath according to claim 1, characterized in that, The second preset pH value in the step 2) is 7-9.

5. The method for pre-treating radioactive waste liquid for washing according to any one of claims 1 to 4, characterized in that, The reverse osmosis is 1-3 grade reverse osmosis.

6. A system for use in the method for the pre-treatment of radioactive waste solutions for washing, according to any one of claims 1 to 5, characterised in that it comprises: The method comprises: a reaction device for passing in the bathing radioactive waste liquid, adjusting the pH value of the bathing radioactive waste liquid to a first preset pH value, then mixing with hydrogen peroxide, and then passing into a Fenton oxidation unit, the Fenton oxidation unit being filled with a Fenton catalyst, and the organic matter in the bathing radioactive waste liquid being oxidized and decomposed; a separation device connected with the reaction unit, the separation unit being used for adjusting the pH value of the water after oxidation and decomposition to a second preset pH value, then performing flocculation and sedimentation, and then performing solid-liquid separation to obtain supernatant; an ultrafiltration device connected with the separation unit, the ultrafiltration unit being used for performing ultrafiltration on the supernatant to obtain ultrafiltration water; a reverse osmosis device connected with the ultrafiltration unit, the reverse osmosis unit being used for removing organic matter from the ultrafiltration water by reverse osmosis, performing separation and concentration to obtain reverse osmosis water and reverse osmosis concentrated water respectively.

7. The system for use in the method of pre-treatment of radioactive waste liquid for bathing according to claim 6, characterized in that, The reaction device comprises: a first pH value adjusting unit for adjusting the pH value of the bathing radioactive waste liquid to a first preset pH value; a hydrogen peroxide unit connected with the first pH value adjusting unit, the hydrogen peroxide unit being used for mixing the bathing radioactive waste liquid with a first preset pH value with hydrogen peroxide; A Fenton oxidation unit is connected with the hydrogen peroxide unit, and is filled with a Fenton catalyst. In the Fenton oxidation unit, the organic matter in the radioactive waste liquid is oxidized and decomposed.

8. The system for use in the method of pre-treatment of radioactive waste liquid for bathing according to claim 6, characterized in that, The separation device comprises: A second pH adjusting unit is connected with the reaction unit, and is used for adjusting the pH value of the oxidized and decomposed effluent to a second preset pH value; A precipitation unit is connected with the second pH adjusting unit, and is used for flocculating and precipitating the oxidized and decomposed effluent with the second preset pH value; A solid-liquid separator is connected with the precipitation unit, and is used for solid-liquid separation to obtain supernatant.

9. The system for use in the method of pre-treatment of radioactive waste liquid for bathing according to claim 6, characterized in that, The ultrafiltration device comprises: An ultrafiltration water supply tank is connected with the separation device, and is used for storing the supernatant; An ultrafiltration membrane assembly is connected with the ultrafiltration water supply tank, and is used for ultrafiltration to obtain ultrafiltration water and ultrafiltration waste water, and the ultrafiltration waste water is returned to the ultrafiltration water supply tank; An ultrafiltration water tank is connected with the ultrafiltration membrane assembly, and the ultrafiltration water flows into the ultrafiltration water tank.

10. The system for use in the method of pre-treatment of radioactive waste liquid for bathing according to claim 9, characterized in that, The ultrafiltration device further comprises: a plurality of medium filters and precision filters connected in sequence arranged on a pipeline between the ultrafiltration water supply tank and the ultrafiltration membrane assembly, and the supernatant flows through the plurality of medium filters and the precision filters in sequence to remove colloids, suspended solid particles and macromolecular particles in the waste water.

11. The system for use in the method of pre-treatment of radioactive waste liquid for bathing according to claim 9, characterized in that, The nominal pore size of the ultrafiltration membrane of the ultrafiltration membrane assembly ranges from 0.03 μm to 0.1 μm.

12. The system for use in the method of pre-treatment of radioactive waste liquid for bathing according to claim 6, characterized in that, The reverse osmosis device comprises: A first-stage reverse osmosis membrane assembly is connected with the ultrafiltration device, and the ultrafiltration water enters the first-stage reverse osmosis membrane assembly, and the water produced by the first-stage reverse osmosis membrane assembly enters a reverse osmosis water tank; A second-stage reverse osmosis membrane assembly is connected with the first-stage reverse osmosis membrane assembly, and the concentrated water of the first-stage reverse osmosis membrane assembly enters the second-stage reverse osmosis membrane assembly, and the water produced by the second-stage reverse osmosis membrane assembly enters the reverse osmosis water tank; A third-stage reverse osmosis membrane assembly is connected with the second-stage reverse osmosis membrane assembly, and the concentrated water of the second-stage reverse osmosis membrane assembly enters the third-stage reverse osmosis membrane assembly, and the water produced by the third-stage reverse osmosis membrane assembly enters the reverse osmosis water tank, and the concentrated water of the third-stage reverse osmosis membrane assembly enters a reverse osmosis concentrated water tank; The reverse osmosis water tank is connected with the first-stage reverse osmosis membrane assembly, the second-stage reverse osmosis membrane assembly and the third-stage reverse osmosis membrane assembly respectively; The reverse osmosis concentrated water tank is connected with the third-stage reverse osmosis membrane assembly.

13. The system for the method of pretreating a radioactive waste liquid for bathing according to claim 12, wherein The first-stage reverse osmosis membrane assembly is a three-stage type, and the number ratio of the membrane shells of each stage is 2:1:1; The second-stage reverse osmosis membrane assembly is a two-stage type, and the number ratio of the membrane shells of the two stages is 1:1; The third-stage reverse osmosis membrane assembly is a two-stage type, and the number ratio of the membrane shells of the two stages is 1:

1.

14. The system for use in the method of pre-treatment of radioactive waste liquid for bathing according to claim 12, characterized in that, Further comprising: A discharge facility or a deep purification device is connected with the reverse osmosis water tank, and the reverse osmosis water enters the discharge facility for discharge or the deep purification device for deep purification; An evaporation and concentration device or a cement solidification device is connected with the reverse osmosis concentrated water tank, and the reverse osmosis concentrated water enters the evaporation and concentration device for evaporation and concentration or the cement solidification device for cement solidification.

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