Mobile radioactive decontamination wastewater treatment device and method

Abstract

The invention relates to a movable radioactive decontamination wastewater treatment device and method. The device comprises a folding water bag and a vehicle, the vehicle is provided with a square cabin, a radioactive decontamination wastewater treatment system is arranged in the square cabin, the cover system comprises a bag type filter connected with the folding water bag through a quick connector, and the bag type filter is sequentially connected with an activated carbon adsorption filter, a security filter and a purification reverse osmosis device; a produced water output end of the purification reverse osmosis device is sequentially connected with the continuous electrodeionization device and the ion exchange bed; an output port of the continuous electrodeionization device is respectively connected with the folding water bag and the concentrated water tank through the three-way electric valve; and a concentrated water output end of the purification reverse osmosis device is connected to the folding water bag. The device is simple and convenient to operate and maintain, has personnel radiation protection measures, and can realize automatic operation and monitoring functions.

Description

Technical Field

[0001] This invention relates to radioactive decontamination wastewater, specifically a mobile radioactive decontamination wastewater treatment device and method, belonging to the field of nuclear waste treatment technology. Background Technology

[0002] With the continuous construction and operation of nuclear power plants in my country, the increasing prevalence of nuclear medical technologies (such as PET-CT and radioactive isotope therapy), and the growing need for nuclear accident emergency response, the safe treatment and disposal of radioactive wastewater is an indispensable part of nuclear technology applications, and its risks to the environment and public health cannot be ignored. Traditional water treatment facilities are mostly fixed and large-scale in design and construction, making it difficult to effectively meet the needs of operations in remote areas or emergency response to sudden incidents. For institutions such as civilian irradiation stations and medical facilities that generate small amounts of wastewater and are geographically dispersed, there are also inherent drawbacks such as high investment costs and geographical limitations.

[0003] Therefore, developing a highly integrated, rapidly deployable, efficient, intelligently operated, and low-volume mobile wastewater treatment method and device has become an urgent technical problem to be solved. Summary of the Invention

[0004] The present invention aims to provide a highly integrated mobile decontamination radioactive wastewater treatment device and method that can rapidly treat radioactive wastewater with relatively complex composition and produce low secondary waste. The device is simple and convenient to operate and maintain, has personnel radiation protection measures, and can realize automated operation and monitoring functions.

[0005] The technical solution adopted to achieve the purpose of this invention is a mobile radioactive decontamination wastewater treatment device, which includes: Foldable water bladder; vehicle; The modular shelter is installed on the vehicle. A radioactive decontamination wastewater treatment system, located within the container, includes a bag filter connected to the folded water bladder via a quick connector. The bag filter is sequentially connected to an activated carbon adsorption filter, a security filter, a primary purification reverse osmosis unit, and a secondary purification reverse osmosis unit. The permeate from the primary purification reverse osmosis unit flows into the secondary purification reverse osmosis unit, and the permeate output of the secondary purification reverse osmosis unit is connected to a continuous electro-desalination unit. The permeate output of the continuous electro-desalination unit is connected to an ion exchange bed. The concentrate output of the primary purification reverse osmosis unit is connected to the folded water bladder, and the concentrate from the secondary purification reverse osmosis unit flows into the security filter. The concentrate output port of the continuous electro-desalination unit is connected to the folded water bladder and the concentrate tank via a first three-way electric valve.

[0006] Furthermore, the bag filter and the activated carbon adsorption filter are connected by a second three-way electric valve. The third channel of the second three-way electric valve is connected to the concentrate tank. A pipeline is provided between the outlet and the inlet of the concentrate tank. A booster pump, a plunger pump, and a concentration reverse osmosis device are sequentially installed on the pipeline.

[0007] In the above technical solution, a conductivity meter is provided between the folded water bladder and the bag filter.

[0008] In the above technical solution, pressure monitoring devices and flow monitoring devices are respectively provided between the bag filter and the activated carbon adsorption filter, between the security filter and the primary purification reverse osmosis device, between the primary purification reverse osmosis device and the secondary purification reverse osmosis device, and between the secondary purification reverse osmosis device and the continuous electro-deionization device; a monitoring device is provided at the outlet of the ion exchange bed.

[0009] Furthermore, the mobile radioactive decontamination wastewater treatment device of the present invention also includes a control system, an online environmental monitoring instrument, protective equipment, and a generator set. The protective equipment and generator set are located between the driver's cab and the container. When the online environmental monitoring instrument located in the external environment detects radioactive contamination in the external environment, the control system activates the protective equipment to maintain a positive pressure protection state in the driver's cab, while efficiently filtering the external air to ensure the safety of the driver.

[0010] The treatment methods of the aforementioned mobile radioactive decontamination wastewater treatment device include: Wastewater in the pleated water bladder is pretreated by a bag filter, an activated carbon adsorption filter, and a security filter. After pretreatment, the wastewater enters the first-stage purification reverse osmosis unit for further treatment. The permeate from the first-stage purification reverse osmosis unit enters the second-stage purification reverse osmosis unit, and the concentrated water flows into the folded water bag. The permeate from the secondary purification reverse osmosis unit enters the continuous electro-desalination unit, and the permeate from the continuous electro-desalination unit enters the ion exchange bed. The output of the ion exchange bed is discharged after being monitored by a monitoring device. The concentrate from the secondary purification reverse osmosis unit flows into the security filter. The concentrate from the continuous electro-deionization unit enters either the folded water bladder or the concentrate tank via the first three-way electric valve.

[0011] After continuous circulation treatment, switch the second three-way electric valve to discharge the wastewater in the folded water bag into the concentrate tank; the wastewater in the concentrate tank is then discharged after being concentrated by the concentration reverse osmosis device.

[0012] The present invention has the following advantages: 1. Highly integrated: The radioactive decontamination wastewater treatment system of this invention is located in a vehicle cabin and integrates various purification and concentration devices. It can be quickly deployed by vehicle to achieve efficient treatment of radioactive wastewater.

[0013] 2. Bag filters, activated carbon adsorption filters, and security filters can be used to treat wastewater containing surfactants, oil impurities, or high salt content.

[0014] 3. The concentrate tank achieves circulation concentration through a booster pump, plunger pump, and concentration reverse osmosis device, resulting in a high concentration ratio and low secondary waste production.

[0015] 4. When the online environmental monitoring instrument located in the external environment detects radioactive contamination in the external environment, the control system activates the protective equipment to maintain a positive pressure protection state in the cockpit, while efficiently filtering the external air to ensure the safety of the driver. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the mobile radioactive decontamination wastewater treatment device of the present invention.

[0017] Figure 2 for Figure 1 A schematic diagram of the structure of a radioactive decontamination wastewater treatment system. Detailed Implementation

[0018] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0019] like Figure 1 As shown, the mobile radioactive decontamination wastewater treatment device of the present invention includes a vehicle and a foldable water bladder. The vehicle is equipped with a container, and the container is equipped with a radioactive decontamination wastewater treatment system. The foldable water bladder is connected to the inlet and outlet of the radioactive decontamination wastewater treatment system through a quick connector.

[0020] like Figure 2 As shown, the radioactive decontamination wastewater treatment system includes a bag filter, an activated carbon adsorption filter, a security filter, a primary reverse osmosis (RO) unit, a secondary RO unit, a continuous electro-desalination (EDI) unit, and an ion exchange bed. A pleated water tank is sequentially connected to the bag filter, activated carbon adsorption filter, security filter, and primary RO unit. The concentrate output of the primary RO unit is connected to the pleated water tank, the permeate output of the primary RO unit is connected to the secondary RO unit, the permeate output of the secondary RO unit is connected to the continuous electro-desalination (EDI) unit, and the permeate output of the continuous EDI unit is connected to the ion exchange bed. The concentrate output port of the continuous EDI unit is connected to the pleated water tank and the concentrate tank via a first three-way electric valve. A monitoring device is installed at the output of the ion exchange bed.

[0021] A conductivity meter is installed between the pleated water bladder and the bag filter. The bag filter and the activated carbon adsorption filter are connected by a second three-way electric valve. The third channel of the second three-way electric valve is connected to the concentrate tank. A pipeline is installed between the outlet and the inlet of the concentrate tank. A booster pump, a plunger pump and a concentration reverse osmosis device are installed in sequence on the pipeline.

[0022] The bag filter used in this invention is designed to trap suspended particulate matter larger than 10μm. The bag is filled with oil-absorbing cotton, providing oil absorption without water absorption, and is used for the initial removal of oil from wastewater. To prevent filter clogging from affecting the overall vehicle operation, one bag filter is used in operation and one is on standby.

[0023] To improve purification efficiency, the reverse osmosis purification device can include multiple stages of reverse osmosis. For example, in this embodiment, a first-stage reverse osmosis device and a second-stage reverse osmosis device are connected in series. Each stage of the reverse osmosis device can also be equipped with multiple reverse osmosis devices. For example, in this embodiment, the first-stage reverse osmosis device has two reverse osmosis devices RO1 connected in parallel, and the second-stage reverse osmosis device has two reverse osmosis devices RO2.

[0024] Furthermore, pressure and flow monitors can be installed between various components in the radioactive decontamination wastewater treatment system as needed. For example, pressure and flow monitors are installed between bag filters and activated carbon adsorption filters, between the first-stage reverse osmosis unit RO1 and the second-stage reverse osmosis unit RO2, and between the second-stage reverse osmosis unit RO2 and the continuous electrostatic desalination unit. This invention achieves dynamic flow matching between various equipment levels through real-time monitoring and interlocking design of flow and pressure between equipment levels, eliminating the need for buffer tanks and product water tanks in multi-stage reverse osmosis processes and further saving layout space.

[0025] The mobile radioactive decontamination wastewater treatment device of this invention is also equipped with: a control system, an online environmental monitoring instrument, protective equipment, and a generator set. The protective equipment and generator set are located between the driver's cab and the container. When the online environmental monitoring instrument detects radioactive contamination in the external environment, the control system activates the protective equipment to maintain a positive pressure protection state in the driver's cab, while simultaneously filtering the outside air efficiently to ensure the safety of the driver. The generator set is an integrated generator set used to power various electrical equipment at the emergency site.

[0026] The mobile radioactive decontamination wastewater treatment device of the present invention includes a purification process and a concentration process, which are described below: The wastewater purification process includes: S1. Wastewater passes through a bag filter and an activated carbon adsorption filter.

[0027] The oil-absorbing cotton in the bag filter and the activated carbon in the activated carbon adsorption filter have excellent adsorption capacity for oil and surfactants. This process is a pretreatment used to remove particulate matter, oil, surfactants, and some iodine and cesium from the radioactive decontamination wastewater. The pretreatment equipment improves the filter design by filling the bag filter with oil-absorbing cotton and using a large amount of activated carbon after the bag filter and before the first-stage reverse osmosis, simplifying the equipment configuration and process of the pretreatment.

[0028] In existing technologies, the pretreatment of this type of wastewater typically involves a combination of processes such as flocculation sedimentation, activated carbon filtration, oil-water separator, and microfiltration / ultrafiltration. Ultrafiltration / microfiltration operates at high pressures and requires consideration of backwashing, making the structure relatively complex.

[0029] S2. The wastewater pretreated by S1 enters the purification reverse osmosis unit for further treatment.

[0030] After pretreatment by S1, the wastewater passes through a security filter and enters the first-stage reverse osmosis unit RO1. The permeate from the first-stage reverse osmosis unit RO1 enters the second-stage reverse osmosis unit RO2, while the concentrate is returned to the pleated water tank. The permeate from the second-stage reverse osmosis unit RO2 flows into the continuous electro-deionization unit, while the concentrate flows into the security filter.

[0031] S3, Emissions The permeate from the continuous electro-desalination unit passes through an ion exchange bed, and the water discharged from the ion exchange bed is monitored by a monitoring device before being discharged.

[0032] The purification process mainly includes two-stage reverse osmosis, one-stage continuous electro-deionization (EDI), and one-stage ion exchange bed. Field tests show that pretreated wastewater with a cesium content >1×105μg / L, after passing through the first-stage reverse osmosis RO1, the second-stage reverse osmosis RO2, EDI, and ion exchange bed in sequence, has a cesium content of <0.5μg / L in the purified effluent, with a decontamination capacity >1×105.

[0033] The wastewater concentration process includes: S4. The concentrate from the first-stage reverse osmosis unit RO1 flows back to the collapsible water tank for continuous circulation. When the conductivity meter detects that the conductivity of the outlet of the collapsible water tank is 5 to 10 times the initial conductivity, the three-way electric valve is switched to discharge the wastewater in the collapsible water tank into the concentrate tank.

[0034] S5. Wastewater from the concentrate tank is concentrated to more than 40 times its original volume via RO3 circulation before being discharged. Specifically: The concentrated water in the concentrate tank is pressurized by a booster pump and a plunger pump, and then concentrated to more than 40 times its original volume through a reverse osmosis (RO) system before being discharged and stored in barrels for solidification treatment.

[0035] Field tests show that wastewater with an influent conductivity of 800~1400μs / m³, after being circulated and concentrated through the above process, produces a concentrate with a conductivity of 35000μs / m³ and a volume of 170L, achieving a concentration ratio of up to 59 times.

[0036] Based on the characteristics of radioactive decontamination wastewater and the special requirements of emergency equipment, the mobile radioactive decontamination wastewater treatment device of this invention can be quickly mobilized to the accident site to complete on-site treatment and discharge of wastewater (the purified water meets the requirements of total α≤1Bq / L and total β≤10Bq / L); the system concentration ratio (inlet water volume / concentrate volume) >50; and it can protect the personnel in the cockpit from external environmental contamination.

[0037] Due to the limited space in the design and layout of mobile devices, and the complex composition of radioactive decontamination wastewater (typically containing oil, surfactants, and impurities), which usually requires the purified wastewater to meet the limits for direct discharge under standard regulations, high demands are placed on the configuration, ease of operation, and convenient maintenance of the process system. Therefore, considering the characteristics of the aforementioned radioactive decontamination wastewater and the need for highly integrated, easy-to-operate, and easy-to-maintain mobile wastewater treatment devices, this invention has made the following improvements in the process route and equipment selection: (1) To improve the system's adaptability to raw water and fully utilize the good adsorption capacity of oil-removing cotton and activated carbon for oil and surfactants, the design of the filters in the pretreatment equipment was improved. Oil-removing cotton was filled into the bag filter, and activated carbon was used extensively after the bag filter and before the first-stage purification reverse osmosis unit to simplify the equipment configuration and process of the pretreatment process. (Usually, the pretreatment of this type of wastewater includes a combination of processes such as flocculation sedimentation, activated carbon filtration, oil-water separator, and microfiltration / ultrafiltration. Ultrafiltration / microfiltration has a high operating pressure and requires consideration of backwashing, making the structure relatively complex.) At the same time, the first-stage purification reverse osmosis unit directly selects seawater reverse osmosis membranes (suitable for feed water with a salt content of 10,000~15,000 μs / m³, which are more adaptable to interference impurities with high COD content such as oil and surfactants than the antifouling membranes usually selected for reverse osmosis membranes) to improve the system's adaptability to complex raw water.

[0038] (2) Compared with conventional water treatment systems, the number of containers such as raw water tank, buffer water tank and product water tank is reduced. The present invention uses a foldable water bladder to realize the receiving and buffering functions of raw water, and only retains the concentrate tank. The tank plate is made of metal plate with lead sandwich, which reduces the exposure of operators.

[0039] Both the inlet and outlet of the primary reverse osmosis unit RO1 and the secondary reverse osmosis unit RO2 are equipped with flow sensors and pressure sensors. Through real-time monitoring and interlocking design of flow and pressure between each stage of the equipment, dynamic flow matching between the various stages of the purification unit is achieved. This eliminates the need for buffer tanks and product water tanks in multi-stage reverse osmosis processes, further saving layout space. (See pressure and flow monitoring point layout for...) Figure 1 ) (3) The activated carbon column and ion exchange column are miniaturized and have quick-connect interfaces; easy to maintain and replace; the total weight of a single activated carbon column and ion exchange column is controlled within 100kg (multiple columns are connected in parallel), which facilitates on-site installation and disassembly (two people can complete on-site replacement and installation without the need for handling or hoisting tools).

[0040] (4) In order to improve the service life of ion exchange resin, reduce the frequency of replacement, and prevent Cs from penetrating, an EDI device is installed at the front end of the ion exchange resin to ensure the system's decontamination efficiency.

Claims

1. A mobile radioactive decontamination wastewater treatment device, characterized in that, include: Foldable water bladder; vehicle; The modular shelter is installed on the vehicle. A radioactive decontamination wastewater treatment system, located within the container, includes a bag filter connected to the folded water bladder via a quick connector. The bag filter is sequentially connected to an activated carbon adsorption filter, a security filter, a primary purification reverse osmosis unit, and a secondary purification reverse osmosis unit. The permeate from the primary purification reverse osmosis unit flows into the secondary purification reverse osmosis unit, and the permeate output of the secondary purification reverse osmosis unit is connected to a continuous electro-desalination unit. The permeate output of the continuous electro-desalination unit is connected to an ion exchange bed. The concentrate output of the primary purification reverse osmosis unit is connected to the folded water bladder, and the concentrate from the secondary purification reverse osmosis unit flows into the security filter. The concentrate output port of the continuous electro-desalination unit is connected to the folded water bladder and the concentrate tank via a first three-way electric valve.

2. The mobile radioactive decontamination wastewater treatment device according to claim 1, characterized in that: The bag filter and the activated carbon adsorption filter are connected by a second three-way electric valve. The third channel of the second three-way electric valve is connected to the concentrate tank. A pipeline is provided between the outlet and the inlet of the concentrate tank. A booster pump, a plunger pump and a concentration reverse osmosis device are sequentially installed on the pipeline.

3. The mobile radioactive decontamination wastewater treatment device according to claim 2, characterized in that: A conductivity meter is installed between the folded water bladder and the bag filter.

4. The mobile radioactive decontamination wastewater treatment device according to claim 3, characterized in that: Pressure monitoring devices and flow monitoring devices are respectively installed between the bag filter and the activated carbon adsorption filter, between the security filter and the primary purification reverse osmosis unit, between the primary purification reverse osmosis unit and the secondary purification reverse osmosis unit, and between the secondary purification reverse osmosis unit and the continuous electro-deionization unit; a monitoring device is installed at the outlet of the ion exchange bed.

5. The mobile radioactive decontamination wastewater treatment device according to any one of claims 1-4, characterized in that: It also includes a control system, an online environmental monitoring instrument, protective equipment, and a generator set, which are located between the vehicle's cab and the container. When the online environmental monitoring instrument detects radioactive contamination in the external environment, the control system activates the protective equipment to maintain a positive pressure protection state in the cab and efficiently filter the outside air to ensure the safety of the driver.

6. A mobile method for treating radioactive decontamination wastewater, characterized in that, include: Wastewater in the pleated water bladder is pretreated by a bag filter, an activated carbon adsorption filter, and a security filter. After pretreatment, the wastewater enters the first-stage purification reverse osmosis unit for further treatment. The permeate from the first-stage purification reverse osmosis unit enters the second-stage purification reverse osmosis unit, and the concentrated water flows into the folded water bag. The permeate from the secondary purification reverse osmosis unit enters the continuous electro-desalination unit, the permeate from the continuous electro-desalination unit enters the ion exchange bed, and the output of the ion exchange bed is discharged after being monitored by a monitoring device. The concentrated water from the secondary reverse osmosis purification unit flows into the security filter; The concentrate from the continuous electro-deionization unit enters either the folded water bladder or the concentrate tank via the first three-way electric valve.

7. The mobile radioactive decontamination wastewater treatment method according to claim 6, characterized in that, Also includes: After continuous circulation treatment, switch the second three-way electric valve to discharge the wastewater in the folded water bag into the concentrate tank; Wastewater from the concentrate tank is concentrated and then discharged after being circulated through a reverse osmosis concentration unit.

Images