An electrochemical carbon membrane reactor for removing cesium ions from water and its operating process.

Abstract

This invention discloses an electrochemical carbon membrane reactor and its operating process for removing cesium ions from water, relating to the field of cesium ion separation. The device mainly includes a functional carbon membrane anode, a functional carbon membrane cathode, a regulated power supply, a water pump, sensors, and a casing. During operation, the cesium-containing solution to be treated is pumped from the raw water tank to port A, entering the anode chamber. It then sequentially penetrates the carbon membrane anode and cathode, reaching the cathode chamber and finally flowing into the product water tank from port B, yielding treated water. This invention utilizes both the electrostatic repulsion of the carbon membrane anode and the electrochemical adsorption of the carbon membrane cathode as core processes to remove cesium ions from water. Furthermore, the device's performance can be restored and regenerated through periodic removal of the concentrate and electrode reversal. This process has the advantages of simple equipment, simple operation steps, low production cost, and high cesium ion removal rate, and can be applied to the effective separation and removal of cesium ions in industrial wastewater, salt lake water, nuclear wastewater, seawater, and other water bodies.

Description

Technical Field

[0001] This invention relates to an electrochemical carbon membrane reactor and its operating process for removing cesium ions from water, belonging to the field of water treatment technology. Background Technology

[0002] Nuclear energy, as a renewable energy source, has been widely used in various fields due to its low carbon emissions, high efficiency, and low cost. However, the development and rapid growth of nuclear energy worldwide has inevitably led to various environmental problems caused by radioactive pollutants, such as nuclear waste containing radionuclides, nuclear wastewater, and nuclear wastewater generated by accidents.

[0003] Multiple radionuclides are frequently found in aqueous radioactive waste streams, among which cesium-137 is a high-level waste nuclide that poses a considerable risk to the environment and health. Due to its long half-life (approximately 30 years), high solubility in water, and radioactivity as a gamma radiation source, cesium-137 poses a significant threat to the environment and human health. Furthermore, because cesium-137 has poor degradation capabilities and is prone to accumulation, it may cause somatic cellular and genetic problems in organisms.

[0004] Currently, methods for removing cesium ions from water mainly include chemical precipitation, solvent extraction, membrane separation, biological treatment, and adsorption. However, these methods still have some shortcomings in removing radioactive cesium from water. For example, chemical precipitation introduces large amounts of salts, potentially leading to excessive anions or pH levels in the effluent; some solvents used in solvent extraction are highly toxic; biological treatment requires stringent conditions and has low efficiency; and membrane separation technology primarily relies on physical retention, resulting in low overall efficiency and the risk of membrane fouling. Summary of the Invention

[0005] To address the problems of existing technologies, this invention proposes an electrochemical carbon membrane reactor and its operating process for removing cesium ions from water. The reactor uses a porous conductive carbon membrane as its core component, and through the introduction of electrochemical action, it synergistically utilizes the electric field repulsion function of the carbon membrane anode and the electrochemical adsorption function of the carbon membrane cathode. This electrochemical carbon membrane reactor can achieve highly efficient removal of cesium ions from water and is easy to regenerate. The device and its operating process have advantages such as simple equipment, simple operation steps, low operating costs, and high cesium ion removal rate.

[0006] To achieve the above objectives, the present invention specifically adopts the following technical solution: an electrochemical carbon membrane reactor for removing cesium ions from water, comprising: a membrane module, a power supply, a raw water tank, and a product water tank; the membrane module includes a membrane module shell, and a carbon membrane anode and a carbon membrane cathode are disposed inside the membrane module shell, the carbon membrane anode and the carbon membrane cathode are arranged in parallel and are respectively connected to the positive and negative terminals of the power supply; the cavity formed by the carbon membrane anode and the membrane module shell is the anode chamber, the cavity formed by the carbon membrane cathode and the membrane module shell is the cathode chamber, and the cavity formed by the carbon membrane anode, the carbon membrane cathode, and the membrane module shell is the buffer chamber, the buffer chamber being located between the anode chamber and the cathode chamber; the anode chamber is connected to the raw water tank, and the cathode chamber is connected to the product water tank; a cesium ion sensor I is disposed in the buffer chamber, and a cesium ion sensor II is disposed in the cathode chamber, which can monitor the concentration of cesium ions in the solution; the anode chamber has an inlet A and an outlet C, the cathode chamber has an outlet B and an outlet E, and the buffer chamber has an inlet D.

[0007] Furthermore, both the carbon film anode and carbon film cathode materials are porous flat plate structures with good conductivity, and the pore size is between 0.05μm and 10μm, with a porosity between 10% and 90%.

[0008] Furthermore, the carbon film anode is a homogeneous or composite film prepared using one or more of the following as precursors: graphite, petroleum coke, coal, carbon fiber, activated carbon, graphene, carbon nanotubes, MOF pyrolytic carbon, etc.

[0009] Furthermore, the carbon film cathode is a functional carbon film cathode, which is obtained by loading Prussian blue or Prussian blue analogues onto a carbon film matrix. The Prussian blue analogues include: copper hexacyanoferrate, cobalt hexacyanoferrate, nickel hexacyanoferrate, zinc hexacyanoferrate, titanium hexacyanoferrate, manganese hexacyanoferrate, etc. The precursor material and structure of the carbon film matrix are consistent with those of the carbon film anode. That is, the carbon film cathode is a homogeneous membrane or composite membrane prepared by using one or more of the following as precursors: graphite, petroleum coke, coal, carbon fiber, activated carbon, graphene, carbon nanotubes, MOF pyrolytic carbon, etc.

[0010] Furthermore, the loading method is one of impregnation-ion exchange, chemical deposition, electrochemical deposition, in-situ growth, and physical doping.

[0011] Furthermore, a water pump is provided between the anode chamber and the raw water tank, and between the cathode chamber and the product water tank.

[0012] Furthermore, each of the following water inlets is equipped with a valve: A inlet valve, C outlet valve, B outlet valve, E outlet valve, and D inlet valve. Specifically, the valve at A inlet valve is an A-port valve, the valve at C outlet valve is a C-port valve, the valve at B outlet valve is a B-port valve, the valve at E outlet valve is an E-port valve, and the valve at D inlet valve is a D-port valve.

[0013] Furthermore, the membrane module may be one or more, and the multiple membrane modules may be connected in parallel.

[0014] An operating process for the electrochemical carbon membrane reactor for removing cesium ions from water is as follows: First, valves C, D, and E are kept closed. The cesium-containing solution to be treated is pumped from the raw water tank to the anode chamber via inlet A, passing through the carbon membrane anode and cathode in sequence, reaching the cathode chamber, and finally flowing into the product water tank from outlet B to obtain treated water. During operation, the carbon membrane anode effectively retains cesium ions in the water in the anode chamber through electrostatic repulsion. Furthermore, when the concentration of the concentrate in the anode chamber is too high, causing the permeate to pass through the buffer chamber and approach the carbon membrane cathode, the cesium ions can be further removed by electrochemical enhanced adsorption.

[0015] Furthermore, the electrochemical carbon membrane reactor for removing cesium ions from water operates at a voltage between 1.0 and 20V.

[0016] Furthermore, the cesium ion sensor I can monitor the concentration of cesium ions in the buffer chamber in real time. During operation, when the presence of cesium ions in the buffer chamber is detected or the cesium ion concentration reaches a certain threshold, it indicates that the cesium ions in the anode chamber have been concentrated to a high concentration, and the carbon film anode cannot completely retain the cesium ions in the water. At this time, the power is disconnected, valves A and B are closed, valves C and D are opened, and clean water or cleaning solution is pumped in from the D inlet to discharge the concentrated solution in the anode chamber from port C. Then, valves A (7-1) and B are opened, valves C and D are closed, the power is turned on, and the device resumes normal operation.

[0017] Furthermore, the cesium ion sensor II can monitor the concentration of cesium ions in the cathode chamber in real time. During operation, when the presence of cesium ions in the cathode chamber is detected or the cesium ion concentration reaches a certain threshold, it indicates that the carbon film cathode adsorption has reached saturation. At this time, the power supply is reversed to achieve desorption and regeneration of the carbon film cathode. At the same time, valves A and B are closed, and valves D and E are opened. Clean water or cleaning solution is pumped in from the D inlet to discharge the cesium ion-containing solution desorbed from the carbon film cathode from the E outlet. Then, valves A and B are opened, valves D and E are closed, the power supply is turned on, and the device resumes normal operation.

[0018] Furthermore, the cesium-containing liquid to be treated is at least one of industrial wastewater, salt lake water, nuclear wastewater, and seawater containing cesium ions; the device can be applied to the effective separation and removal of cesium ions in water bodies such as industrial wastewater, salt lake water, nuclear wastewater, and seawater.

[0019] Furthermore, the device can be used in parallel with multiple membrane modules simultaneously, and by staggering the collection of concentrate and the regeneration time, the entire system can achieve continuous selective separation of cesium ions in water.

[0020] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit the invention. Other features and advantages of the invention will become clearer after reading the detailed embodiments in conjunction with the accompanying drawings.

[0021] The advantages and beneficial effects of this invention are as follows:

[0022] To address the problems of low cesium ion removal rates and complex operations in existing technologies, this invention provides a novel method for removing cesium ions from water. The electrochemical carbon membrane reactor constructed in this invention, for the first time, synergistically utilizes the dual functions of the anode and cathode of the conductive carbon-based membrane material. Electric field repulsion and electrochemical adsorption are used as the core processes to achieve highly efficient removal of cesium ions from water. Furthermore, the removal performance can be restored and regenerated by periodically removing the concentrate and reversing the electrode. By using multiple membrane modules in parallel simultaneously and staggering the collection of concentrate and regeneration times, continuous and selective separation of cesium ions from water is achieved throughout the system. This invention offers advantages such as simple equipment, straightforward operation, low operating costs, and high cesium ion removal rates, demonstrating promising prospects for industrialization. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the electrochemical carbon membrane reaction device for removing cesium ions from water in Example 1.

[0024] In the diagram: 1. Carbon membrane anode, 2. Carbon membrane cathode, 3. Regulated power supply, 4. Water pump, 5-1. Cesium ion sensor I, 5-2. Cesium ion sensor II, 6. Membrane module housing, 6-1. Anode chamber, 6-2. Cathode chamber, 6-3. Buffer chamber, 7-1. A-port valve, 7-2. B-port valve, 7-3. C-port valve, 7-4. D-port valve, 7-5. E-port valve, 8. Raw water tank, 9. Product water tank. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are only for illustration and explanation of the present invention and are not intended to limit the present invention.

[0026] Example 1

[0027] like Figure 1 As shown, an electrochemical carbon membrane reactor for removing cesium ions from water includes: a power supply 3, a membrane module, a raw water tank 8, and a product water tank 9. The membrane module includes a membrane module housing 6, within which a carbon membrane anode 1 and a carbon membrane cathode 2 are disposed. The carbon membrane anode 1 and carbon membrane cathode 2 are arranged in parallel. The carbon membrane anode 1 is connected to the positive terminal of the power supply 3, and the carbon membrane cathode 2 is connected to the negative terminal of the power supply 3. The cavity formed by the carbon membrane anode 1 and the membrane module housing 6 is an anode chamber 6-1, and the cavity formed by the carbon membrane cathode 2 and the membrane module housing 6 is a cathode chamber 6-2. The cavity formed by the cathode 2 and the membrane module housing 6 is a buffer chamber 6-3, located between the anode chamber 6-1 and the cathode chamber 6-2. The anode chamber 6-1 is connected to the raw water tank 8, and the cathode chamber 6-2 is connected to the product water tank 9. A cesium ion sensor 5-1 is installed in both the buffer chamber 6-3 and the cathode chamber 6-2, which can monitor the concentration of cesium ions in the solution. The anode chamber 6-1 has an inlet A and an outlet C, the cathode chamber 6-2 has an outlet B and an outlet E, and the buffer chamber 6-3 has an inlet D, all equipped with valves. A water pump 4 is installed between the anode chamber 6-1 and the raw water tank 8, and between the cathode chamber 6-2 and the product water tank 9.

[0028] In an electrochemical carbon membrane reactor for removing cesium ions from water, two porous flat graphite-based carbon membranes were used as the anode and cathode, respectively. The membrane pore size was 1.5 μm, the length was 10 cm, the width was 10 cm, the thickness was 1 cm, and the porosity was 41%. Prussian blue was uniformly loaded onto the carbon membrane cathode using chemical deposition: the graphite-based carbon membrane was immersed in a 0.1 M ferric chloride solution for 30 min, then immersed in a 0.08 M potassium ferrocyanide solution for 30 min. After the reaction, it was rinsed with deionized water, and this process was repeated 5 times to form a Prussian blue layer on the carbon membrane. Finally, it was dried in a drying oven at 70 °C for 300 min. Seawater with a cesium ion concentration of 2 ppm was used as the treatment solution and stored in raw water tank 8. During operation, first turn on the DC power supply 3 to provide a stable voltage of 2.5V, keep valves 7-3 at port C, 7-4 at port D, and 7-5 at port E closed, and use water pump 4 to transport the cesium-containing liquid to be treated from the raw water tank 8 to port A and enter the anode chamber 6-1. It then passes through the carbon film anode 1 and carbon film cathode 2 in sequence, reaches the cathode chamber 6-2, and finally flows into the product water tank 9 from port B to obtain the treated water. At this time, the cesium ion removal rate reaches 100%.

[0029] After 5 hours of operation, when the cesium ion sensor I5-1 detects that the concentration of cesium ions in buffer chamber 6-3 reaches 0.01 ppm, power supply 3 is disconnected, valves A-port 7-1 and B-port 7-2 are closed, valves C-port 7-3 and D-port 7-4 are opened, and clean water is pumped in from port D to discharge the concentrated solution in anode chamber 6-1 from port D. Then, valves A-port 7-1 and B-port 7-2 are opened, valves C-port 7-3 and D-port 7-4 are closed, power supply 3 is turned on, and the device resumes normal operation.

[0030] After 30 hours of operation, the cesium ion sensor II5-2 detected a cesium ion concentration of 0.01 ppm in the cathode chamber 6-2. At this point, the power supply 3 was reversed, that is, the original carbon membrane anode 1 was connected to the negative terminal of the power supply 3, and the original carbon membrane cathode 2 was connected to the positive terminal of the power supply 3. At the same time, valves A-port 7-1 and B-port 7-2 were closed, and valves D-port 7-4 and E-port 7-5 were opened. The cesium ion-containing solution obtained from the desorption and regeneration of the carbon membrane cathode 2 was discharged from port E by pumping cleaning solution from port D. Then, valves A-port 7-1 and B-port 7-2 were opened, valves D-port 7-4 and E-port 7-5 were closed, and the power supply 3 was turned on, and the device resumed normal operation.

[0031] Example 2

[0032] like Figure 1 As shown, an electrochemical carbon membrane reactor for removing cesium ions from water includes: a power supply 3, a membrane module, a raw water tank 8, and a product water tank 9. The membrane module includes a membrane module housing 6, within which a carbon membrane anode 1 and a carbon membrane cathode 2 are disposed. The carbon membrane anode 1 and carbon membrane cathode 2 are arranged in parallel. The carbon membrane anode 1 is connected to the positive terminal of the power supply 3, and the carbon membrane cathode 2 is connected to the negative terminal of the power supply 3. The cavity formed by the carbon membrane anode 1 and the membrane module housing 6 is an anode chamber 6-1, and the cavity formed by the carbon membrane cathode 2 and the membrane module housing 6 is a cathode chamber 6-2. The cavity formed by the cathode 2 and the membrane module housing 6 is a buffer chamber 6-3, located between the anode chamber 6-1 and the cathode chamber 6-2. The anode chamber 6-1 is connected to the raw water tank 8, and the cathode chamber 6-2 is connected to the product water tank 9. A cesium ion sensor 5-1 is installed in both the buffer chamber 6-3 and the cathode chamber 6-2, which can monitor the concentration of cesium ions in the solution. The anode chamber 6-1 has an inlet A and an outlet C, the cathode chamber 6-2 has an outlet B and an outlet E, and the buffer chamber 6-3 has an inlet D, all equipped with valves. A water pump 4 is installed between the anode chamber 6-1 and the raw water tank 8, and between the cathode chamber 6-2 and the product water tank 9.

[0033] In an electrochemical carbon membrane reactor for removing cesium ions from water, two porous flat coal-based carbon membranes were used as the anode and cathode, respectively. The membrane pore size was 1.2 μm, the length was 8 cm, the width was 88 cm, the thickness was 1.5 cm, and the porosity was 52%. Cobalt hexacyanoferrate was uniformly loaded onto the carbon membrane cathode using chemical deposition: the carbon membrane was immersed in a 0.08 M cobalt chloride solution for 20 min, then immersed in a 0.05 M potassium ferricyanide solution for 20 min. This process was repeated 10 times to form cobalt hexacyanoferrate on the carbon membrane, which was then dried in a drying oven at 100 °C for 30 min.

[0034] Nuclear wastewater with a cesium ion concentration of 10 ppm was stored in raw water tank 8 as the treatment solution. During operation, DC power supply 3 was first turned on to provide a stable voltage of 3.0V. Valve C-3, valve D-4, and valve E-5 were kept closed. The cesium-containing treatment solution was pumped from raw water tank 8 to anode chamber 6-1 via pump A, passing through carbon film anode 1 and carbon film cathode 2 in sequence, reaching cathode chamber 6-2, and finally flowing into product water tank 9 from port B, resulting in treated water. At this point, the cesium ion removal rate reached 100%.

[0035] After 3 hours of operation, when the cesium ion sensor 5-1 detects that the concentration of cesium ions in the buffer chamber 6-3 reaches 0.01 ppm, power supply 3 is disconnected, valves 7-1 at port A and 7-2 at port B are closed, valves 7-3 at port C and 7-4 at port D are opened, and clean water is pumped in from port D to discharge the concentrated solution in the anode chamber 6-1 from port D. Then, valves 7-1 at port A and 7-2 at port B are opened, valves 7-3 at port C and 7-4 at port D are closed, power supply 3 is turned on, and the device resumes normal operation.

[0036] After 24 hours of operation, the cesium ion sensor II5-2 detected a cesium ion concentration of 0.01 ppm in the cathode chamber 6-2. At this point, the power supply 3 was reversed, that is, the original carbon membrane anode 1 was connected to the negative terminal of the power supply 3, and the original carbon membrane cathode 2 was connected to the positive terminal of the power supply 3. At the same time, valves A-port 7-1 and B-port 7-2 were closed, and valves D-port 7-4 and E-port 7-5 were opened. The cesium ion-containing solution obtained from the desorption and regeneration of the carbon membrane cathode 2 was discharged from port E by pumping cleaning solution from port D. Then, valves A-port 7-1 and B-port 7-2 were opened, valves D-port 7-4 and E-port 7-5 were closed, and the power supply 3 was turned on, and the device resumed normal operation.

[0037] Example 3

[0038] like Figure 1As shown, an electrochemical carbon membrane reactor for removing cesium ions from water includes: a power supply 3, a membrane module, a raw water tank 8, and a product water tank 9. The membrane module includes a membrane module housing 6, within which a carbon membrane anode 1 and a carbon membrane cathode 2 are disposed. The carbon membrane anode 1 and carbon membrane cathode 2 are arranged in parallel. The carbon membrane anode 1 is connected to the positive terminal of the power supply 3, and the carbon membrane cathode 2 is connected to the negative terminal of the power supply 3. The cavity formed by the carbon membrane anode 1 and the membrane module housing 6 is an anode chamber 6-1, and the cavity formed by the carbon membrane cathode 2 and the membrane module housing 6 is a cathode chamber 6-2. The cavity formed by the cathode 2 and the membrane module housing 6 is a buffer chamber 6-3, located between the anode chamber 6-1 and the cathode chamber 6-2. The anode chamber 6-1 is connected to the raw water tank 8, and the cathode chamber 6-2 is connected to the product water tank 9. A cesium ion sensor 5-1 is installed in both the buffer chamber 6-3 and the cathode chamber 6-2, which can monitor the concentration of cesium ions in the solution. The anode chamber 6-1 has an inlet A and an outlet C, the cathode chamber 6-2 has an outlet B and an outlet E, and the buffer chamber 6-3 has an inlet D, all equipped with valves. A water pump 4 is installed between the anode chamber 6-1 and the raw water tank 8, and between the cathode chamber 6-2 and the product water tank 9.

[0039] In an electrochemical carbon membrane reactor for removing cesium ions from water, two porous flat carbon nanotube-based composite carbon membranes were used as the anode and cathode, respectively. The membrane pore size was 2.8 μm, the length was 12 cm, the width was 10 cm, the thickness was 0.1 cm, and the porosity was 66%. Nickel hexacyanoferrate was uniformly loaded onto the carbon membrane cathode using chemical deposition: the carbon membrane was immersed in a 0.08 M nickel nitrate solution for 30 min, then immersed in a 0.05 M potassium ferricyanide solution for 30 min, and this process was repeated 6 times to form nickel hexacyanoferrate on the carbon membrane. Finally, it was dried in a drying oven at 80 °C for 120 min. Salt lake water with a cesium ion concentration of 0.5 ppm was used as the treatment solution and stored in raw water tank 8. During operation, first turn on the DC power supply 3 to provide a stable voltage of 2.5V, keep valves 7-3 at port C, 7-4 at port D, and 7-5 at port E closed, and use water pump 4 to transport the cesium-containing liquid to be treated from the raw water tank 8 to port A and enter the anode chamber 6-1. It then passes through the carbon film anode 1 and carbon film cathode 2 in sequence, reaches the cathode chamber 6-2, and finally flows into the product water tank 9 from port B to obtain the treated water. At this time, the cesium ion removal rate reaches 100%.

[0040] After 10 hours of operation, when the cesium ion sensor I5-1 detects that the concentration of cesium ions in buffer chamber 6-3 reaches 0.02 ppm, power supply 3 is disconnected, valves A-port 7-1 and B-port 7-2 are closed, valves C-port 7-3 and D-port 7-4 are opened, and clean water is pumped in from port D to discharge the concentrated solution in anode chamber 6-1 from port D. Then, valves A-port 7-1 and B-port 7-2 are opened, valves C-port 7-3 and D-port 7-4 are closed, power supply 3 is turned on, and the device resumes normal operation.

[0041] After 72 hours of operation, the cesium ion sensor II5-2 detected a cesium ion concentration of 0.02 ppm in the cathode chamber 6-2. At this point, the power supply 3 was reversed, that is, the original carbon membrane anode 1 was connected to the negative terminal of the power supply 3, and the original carbon membrane cathode 2 was connected to the positive terminal of the power supply 3. At the same time, valves A-port 7-1 and B-port 7-2 were closed, and valves D-port 7-4 and E-port 7-5 were opened. The cesium ion-containing solution obtained from the desorption and regeneration of the carbon membrane cathode 2 was discharged from port E by pumping cleaning solution from port D. Then, valves A-port 7-1 and B-port 7-2 were opened, valves D-port 7-4 and E-port 7-5 were closed, and the power supply 3 was turned on, and the device resumed normal operation.

[0042] Example 4

[0043] like Figure 1 As shown, an electrochemical carbon membrane reactor for removing cesium ions from water includes: a power supply 3, a membrane module, a raw water tank 8, and a product water tank 9. The membrane module includes a membrane module housing 6, within which a carbon membrane anode 1 and a carbon membrane cathode 2 are disposed. The carbon membrane anode 1 and carbon membrane cathode 2 are arranged in parallel. The carbon membrane anode 1 is connected to the positive terminal of the power supply 3, and the carbon membrane cathode 2 is connected to the negative terminal of the power supply 3. The cavity formed by the carbon membrane anode 1 and the membrane module housing 6 is an anode chamber 6-1, and the cavity formed by the carbon membrane cathode 2 and the membrane module housing 6 is a cathode chamber 6-2. The cavity formed by the cathode 2 and the membrane module housing 6 is a buffer chamber 6-3, located between the anode chamber 6-1 and the cathode chamber 6-2. The anode chamber 6-1 is connected to the raw water tank 8, and the cathode chamber 6-2 is connected to the product water tank 9. A cesium ion sensor 5-1 is installed in both the buffer chamber 6-3 and the cathode chamber 6-2, which can monitor the concentration of cesium ions in the solution. The anode chamber 6-1 has an inlet A and an outlet C, the cathode chamber 6-2 has an outlet B and an outlet E, and the buffer chamber 6-3 has an inlet D, all equipped with valves. A water pump 4 is installed between the anode chamber 6-1 and the raw water tank 8, and between the cathode chamber 6-2 and the product water tank 9.

[0044] In an electrochemical carbon membrane reactor for removing cesium ions from water, two porous flat graphene-based carbon membranes were used as the cathode and anode. The membrane pore size was 0.5 μm, the length was 6 cm, the width was 4 cm, the thickness was 50 μm, and the porosity was 37%. Zinc hexacyanoferrate was uniformly loaded onto the carbon membrane cathode via chemical deposition: the carbon membrane was immersed in a 0.05 M zinc nitrate solution for 20 min, then immersed in a 0.05 M potassium ferricyanide solution for 20 min. This process was repeated 8 times to form zinc hexacyanoferrate on the carbon membrane, which was then dried in a drying oven at 100 °C for 30 min.

[0045] The wastewater to be treated is industrial wastewater containing 3 ppm of cesium ions and is stored in raw water tank 8. During operation, DC power supply 3 is first turned on to provide a stable voltage of 3.5V. Valve C-3, valve D-4, and valve E-5 are kept closed. Pump 4 is used to transport the cesium-containing wastewater from raw water tank 8 to port A, where it enters anode chamber 6-1. The cesium-containing wastewater then passes through carbon film anode 1 and carbon film cathode 2, reaching cathode chamber 6-2 and finally flowing into product water tank 9 from port B, resulting in treated water. At this point, the cesium ion removal rate reaches 100%.

[0046] After running for 3 hours, when the cesium ion sensor I5-1 detects that the concentration of cesium ions in buffer chamber 6-3 reaches 0.02 ppm, power supply 3 is disconnected, valves A-port 7-1 and B-port 7-2 are closed, valves C-port 7-3 and D-port 7-4 are opened, and clean water is pumped in from port D to discharge the concentrated solution in anode chamber 6-1 from port D. Then, valves A-port (7-1) and B-port (7-2) are opened, valves C-port (7-3) and D-port (7-4) are closed, power supply 3 is turned on, and the device resumes normal operation.

[0047] After 48 hours of operation, the cesium ion sensor II (5-2) detected a cesium ion concentration of 0.02 ppm in the cathode chamber (6-2). At this point, the power supply 3 was reversed, that is, the original carbon membrane anode 1 was connected to the negative terminal of the power supply 3, and the original carbon membrane cathode 2 was connected to the positive terminal of the power supply 3. At the same time, valves 7-1 at port A and 7-2 at port B were closed, and valves 7-4 at port D and 7-5 at port E were opened. The cesium ion-containing solution obtained from the desorption and regeneration of the carbon membrane cathode 2 was discharged from port E by pumping cleaning solution from port D. Then, valves 7-1 at port A and 7-2 at port B were opened, valves 7-4 at port D and 7-5 at port E were closed, and the power supply 3 was turned on, and the device resumed normal operation.

[0048] Finally, it is necessary to note that the above content is only used to help understand the technical solution of the present invention and should not be construed as a limitation on the scope of protection of the present invention; any non-essential improvements and adjustments made by those skilled in the art based on the above content of the present invention are all within the scope of protection claimed by the present invention.

Claims

1. An electrochemical carbon membrane reactor for removing cesium ions from water, characterized in that: The device includes: a membrane module, a power supply (3), a raw water tank (8), and a product water tank (9); the membrane module includes a membrane module shell (6), and a carbon membrane anode (1) and a carbon membrane cathode (2) are provided inside the membrane module shell (6). The carbon membrane anode (1) and the carbon membrane cathode (2) are arranged in parallel and are respectively connected to the positive and negative terminals of the power supply (3); the cavity formed by the carbon membrane anode (1) and the membrane module shell (6) is the anode chamber (6-1), and the cavity formed by the carbon membrane cathode (2) and the membrane module shell (6) is the cathode chamber (6-2). The carbon membrane anode (1), the carbon membrane cathode (2), and the membrane module shell (6) are connected to the membrane module shell (9). The cavity formed by the shell (6) is a buffer chamber (6-3), which is located between the anode chamber (6-1) and the cathode chamber (6-2). The anode chamber (6-1) is connected to the raw water tank (8), and the cathode chamber (6-2) is connected to the product water tank (9). A cesium ion sensor I (5-1) is installed in the buffer chamber (6-3), and a cesium ion sensor II (5-2) is installed in the cathode chamber (6-2). The anode chamber (6-1) is provided with an inlet A and an outlet C, the cathode chamber (6-2) is provided with an outlet B and an outlet E, and the buffer chamber (6-3) is provided with an inlet D. The carbon film cathode (2) is obtained by loading Prussian blue or a Prussian blue analogue onto a carbon film matrix.

2. The electrochemical carbon membrane reactor for removing cesium ions from water according to claim 1, characterized in that: Both the carbon film anode (1) and the carbon film cathode (2) are porous flat plate structures with pore sizes ranging from 0.05 μm to 10 μm and porosities ranging from 10% to 90%. The carbon film anode (1) is a homogeneous or composite film prepared from one or more of the following as precursors: graphite, petroleum coke, coal, carbon fiber, activated carbon, graphene, carbon nanotubes, and MOF pyrolytic carbon. The precursor material of the carbon film matrix of the carbon film cathode (2) is the same as that of the carbon film anode, and the loading method is one of impregnation-ion exchange, chemical deposition, electrochemical deposition, in-situ growth, and physical doping.

3. The electrochemical carbon membrane reactor for removing cesium ions from water according to claim 1, characterized in that: A water pump (4) is provided between the anode chamber (6-1) and the raw water tank (8), and between the cathode chamber (6-2) and the product water tank (9).

4. The electrochemical carbon membrane reactor for removing cesium ions from water according to claim 1, characterized in that: Valves are installed at inlet A, outlet C, outlet B, outlet E, and inlet D.

5. The electrochemical carbon membrane reactor for removing cesium ions from water according to claim 1, characterized in that: The membrane module may be one or more, and multiple membrane modules may be connected in parallel.

6. The operating process of the electrochemical carbon membrane reactor for removing cesium ions from water as described in any one of claims 1-5, characterized in that: The operating process is as follows: First, keep valves C (7-3), D (7-4) and E (7-5) closed. The cesium-containing liquid to be treated is pumped from the raw water tank (8) to the A inlet by the water pump (4) and enters the anode chamber (6-1). It then passes through the carbon film anode (1) and carbon film cathode (2) in sequence, reaches the cathode chamber (6-2), and finally flows into the product water tank (9) from the B outlet to obtain the treated water. During operation, the carbon membrane anode (1) retains cesium ions in the water in the anode chamber (6-1), and when the concentration of the concentrate in the anode chamber (6-1) is too high, causing the permeate to pass through the carbon membrane cathode (2), the cesium ions are further removed.

7. The operating process of the electrochemical carbon membrane reactor for removing cesium ions from water according to claim 6, characterized in that: The device operates at a voltage between 1.0 and 20 V.

8. The operating process of the electrochemical carbon membrane reactor for removing cesium ions from water according to claim 6, characterized in that: The cesium ion sensor I (5-1) can monitor the concentration of cesium ions in the buffer chamber (6-3) in real time. During operation, when the presence of cesium ions in the buffer chamber (6-3) or the cesium ion concentration reaches a certain threshold is detected, it indicates that the cesium ions in the anode chamber (6-1) are concentrated to a high concentration, and the carbon film anode (1) cannot completely intercept the cesium ions in the water. At this time, the power supply (3) is disconnected, valves A (7-1) and B (7-2) are closed, valves C (7-3) and D (7-4) are opened, and clean water or cleaning solution is pumped in from the D inlet to discharge the concentrated solution in the anode chamber (6-1) from the C inlet. Then, valves A (7-1) and B (7-2) are opened, valves C (7-3) and D (7-4) are closed, the power supply (3) is turned on, and the device resumes normal operation. The cesium ion sensor II (5-2) can monitor the concentration of cesium ions in the cathode chamber (6-2) in real time. During operation, when the presence of cesium ions in the cathode chamber (6-2) or the cesium ion concentration reaches a certain threshold is detected, it indicates that the adsorption of the carbon film cathode (2) has reached saturation. At this time, the power supply (3) is reversed to realize the desorption and regeneration of the carbon film cathode (2). At the same time, the valves A (7-1) and B (7-2) are closed, and the valves D (7-4) and E (7-5) are opened. By pumping clean water or cleaning liquid from the D inlet, the cesium ion-containing solution desorbed from the carbon film cathode (2) is discharged from the E outlet. Then, the valves A (7-1) and B (7-2) are opened, the valves D (7-4) and E (7-5) are closed, the power supply (3) is turned on, and the device resumes normal operation.

9. The operating process of the electrochemical carbon membrane reactor for removing cesium ions from water according to claim 6, characterized in that: The cesium-containing liquid to be treated is at least one of the following: industrial wastewater containing cesium ions, salt lake water, nuclear wastewater, and seawater.

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