A method for inactivating protozoa ameba and its endosymbiont by electrocatalytic water oxidation
By using a carbon-based anode loaded with water-oxidizing material and a bicarbonate electrolyte for electrocatalytic water oxidation, hydrogen peroxide and hydroxyl radicals are generated, solving the problem that traditional disinfection methods are ineffective against amoebas and achieving a highly efficient and environmentally friendly amoeba inactivation effect.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- SUN YAT SEN UNIV
- Filing Date
- 2024-09-05
- Publication Date
- 2026-05-12
AI Technical Summary
Existing technologies are ineffective at inactivating amoebae and the microorganisms within their spores. Traditional disinfection methods, such as chlorine disinfection and ultraviolet light, are ineffective against amoebae, while electrocatalytic oxygen reduction methods rely on oxygenation devices and have limited effectiveness.
A carbon-based material loaded with water oxidation material is used as the anode. Hydrogen peroxide and hydroxyl radicals are generated through electrocatalytic water oxidation. Combined with bicarbonate electrolyte, amoebae and their intracellular microorganisms are inactivated at low voltage. Water oxidation materials such as zinc gallium oxide, bismuth tungstate, and bismuth antimonate are used.
It achieves efficient inactivation of amoebae and their intraspore microorganisms, is simple to operate, low in cost, environmentally friendly, and suitable for various treatment scenarios, especially micro-scale scenarios.
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Figure CN118929858B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of drinking water disinfection technology, specifically relating to a method for inactivating protozoa and their endophytes through electrocatalytic water oxidation. Background Technology
[0002] Currently, disinfection and sterilization methods for water bodies mainly include chemical and physical methods. Physical methods include heating (high temperature), gamma radiation, ultraviolet irradiation, and filtration. Chemical methods include adding heavy metal ions (such as silver and copper), adding alkalis or acids, adding surfactants, and adding oxidants. Among physical methods, filtration is currently the most commonly used physical sterilization method for water bodies. However, due to the need for regular cleaning and replacement of filter cartridges, it cannot completely eliminate microorganisms. Furthermore, microorganisms can form difficult-to-remove biofilms in the filter cartridges or pipes and can accumulate in the filter cartridges, leading to more serious biosafety risks. Ultraviolet and high-temperature sterilization methods are generally difficult to use widely due to equipment limitations and high costs. Among chemical methods, oxidant disinfection is the most widely used, with chlorine and its compounds being the most common, followed by ozone disinfection. However, methods such as adding heavy metal ions (e.g., silver and copper), adding alkalis or acids, and adding surfactants are difficult to apply in many situations due to their environmental unfriendliness and the difficulty in removing byproducts. While oxidizing agents (e.g., chlorination) are effective at inactivating bacteria and other microorganisms, their effectiveness against protozoa (e.g., amoebae, including pathogenic amoebae such as Entamoeba histolytica, Acanthamoeba, and Naegleria fowleri) and their endophytes is not ideal. Therefore, to date, there are few effective disinfection methods for amoebae and their endophytes, and common disinfection methods (such as chlorination, chlorine dioxide, and ultraviolet light) are ineffective at inactivating amoebae. For example, Acanthamoeba cysts can withstand 100 mg / L chlorine for 10 minutes and 50 mg / L chlorine for 18 hours. Furthermore, amoebae spores exhibit excellent tolerance to strong acids and alkalis, high salt concentrations, and high temperatures. Even in high concentrations of hydrogen peroxide, some amoebae spores remain active. Furthermore, even high concentrations of hydrogen peroxide are not very effective at inactivating amoebae cysts. Moreover, as a commonly used oxidizing disinfectant, hydrogen peroxide poses high risks during storage and transportation, and its easy decomposition further restricts its application, especially given the current lack of effective in-situ preparation methods. In addition, the current mainstream electrochemical disinfection method is oxygen reduction, which is effective against bacteria and other microorganisms. However, traditional oxygen reduction requires sufficient oxygen and is ineffective in anaerobic conditions. Furthermore, it only produces hydrogen peroxide, which is still ineffective at inactivating amoebae. Therefore, it is necessary to explore a feasible technology to effectively inactivate amoebae and the microorganisms within their spores.
[0003] Studies have shown that strong oxidizing free radicals, such as hydroxyl radicals, generated by advanced oxidation methods can effectively inactivate amoebae. Therefore, constructing an electrocatalytic disinfection system for aquatic environments using an external power supply is a disinfection method with significant application potential. Current electrocatalytic methods mainly include electrocatalytic oxygen reduction and electrocatalytic water oxidation. Electrocatalytic oxygen reduction heavily relies on aeration devices and only produces hydrogen peroxide, which is ineffective in inactivating amoebae. Furthermore, activating hydrogen peroxide requires additional activators or devices, posing numerous challenges for practical applications. Electrocatalytic water oxidation, on the other hand, does not require additional devices. It can activate the real-time hydrogen peroxide through a reduction reaction coupled at the cathode. Since the electrolyte is potassium bicarbonate, it can react with hydrogen peroxide to produce percarbonate, which, after activation at the cathode, generates carbonate free radicals. Carbonate free radicals have been proven in numerous studies to have a highly effective killing effect on microorganisms. Therefore, developing an electrocatalytic water oxidation technology that effectively inactivates amoebae and their intraspore microorganisms would have significant application potential. Summary of the Invention
[0004] To overcome the shortcomings of the prior art, this invention proposes a method for inactivating amoebae and their intracellular organisms through electrocatalytic water oxidation. This method can inactivate amoebae and their spore-borne endogenous organisms by generating strong oxidizing substances such as hydrogen peroxide and hydroxyl radicals in situ, providing a practical electrocatalytic water oxidation technology for effectively inactivating amoebae and their spore-borne microorganisms.
[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:
[0006] This invention provides a method for inactivating protozoa and their endobiotics by electrocatalytic water oxidation, namely, using a carbon-based material loaded with water oxidation material as the anode, and inactivating the protozoa and their intracellular microorganisms by electrocatalytic water oxidation. The water oxidation material includes zinc gallium oxide, bismuth tungstate, copper tungstate, bismuth antimony, zinc tungstate, and antimony tungstate.
[0007] Preferably, the above-mentioned method for inactivating the protozoan amoebae and its endobiotics by electrocatalytic water oxidation specifically involves: firstly, a water oxidizing material is loaded onto a carbon-based material to form an anode electrode, and nano-zero-valent iron is loaded onto a carbon-based material to form a cathode electrode. Then, the anode and cathode electrodes are inserted into water containing amoebae, bicarbonate electrolyte is added, and electricity is applied, thereby inactivating the amoebae and its intracellular microorganisms by generating strong oxidizing substances. The water oxidizing material includes zinc gallium oxide, bismuth tungstate, copper tungstate, bismuth antimony, zinc tungstate, and antimony tungstate.
[0008] More preferably, the water-oxidizing material includes bismuth antimony, antimony tungstate, and bismuth tungstate, prepared by a hydrothermal method. Other water-oxidizing materials can also be prepared by a hydrothermal method.
[0009] More preferably, the energizing time is at least 2 hours.
[0010] More preferably, the concentration of the bicarbonate electrolyte is 0.5M-3M. The bicarbonate includes sodium bicarbonate, potassium bicarbonate, magnesium bicarbonate, and calcium bicarbonate.
[0011] More preferably, the voltage applied is controlled between 2.7-4V versus RHE.
[0012] More preferably, the stirring process is carried out during the power-on process, and the stirring speed is 100-1000 rpm.
[0013] Furthermore, the hydrothermal method for preparing bismuth antimonate is as follows: Sb2O3 and Bi(NO3)3·5H2O are dissolved in water, the pH is adjusted, and the mixture is subjected to a hydrothermal reaction at 170-190℃ for 40-50 hours. Finally, the precipitate is collected, washed, and dried to obtain the final product.
[0014] Furthermore, the hydrothermal method for preparing antimony tungstate involves dissolving SbCl3 and Na2WO4·2H2O in ethylene glycol, then subjecting the mixture to a hydrothermal reaction at 150-170℃ for 7-13 hours. Finally, the precipitate is collected, washed, and dried to obtain the final product.
[0015] Furthermore, the hydrothermal method for preparing bismuth tungstate is as follows: Bi(NO3)3·5H2O and Na2WO4·2H2O are dissolved in water, and then subjected to a hydrothermal reaction at 170-190℃ for 20-30 hours. Finally, the precipitate is collected, washed, and dried to obtain the final product.
[0016] More preferably, the electrode sheet is prepared by mixing a water-oxidizing material with polyvinylidene fluoride (PVDF) in a ratio of approximately 2-3:1, then adding an appropriate amount of N-methylpyrrolidone (NMP) liquid, and stirring for 5-10 minutes to form a non-sticky slurry. The prepared slurry is then drop-coated onto a carbon-based material and placed in an oven, where it is baked at 150°C for 5-10 minutes to prepare the anode electrode sheet. Additionally, nano-zero-valent iron is loaded onto a carbon-based material using the same method to prepare a cathode electrode sheet.
[0017] Compared with the prior art, the beneficial effects of the present invention are:
[0018] In view of the hazards posed by amoebae and their intracellular microorganisms to human-accessible aquatic environments, this invention provides a method for inactivating amoebae and their intracellular organisms through electrocatalytic water oxidation based on advanced oxidation technology. This method can generate strong oxidizing substances such as hydrogen peroxide and hydroxyl radicals in situ, thereby inactivating amoebae and their endophytic bacteria, with excellent inactivation effect. Furthermore, this invention has the advantages of simple equipment, convenient operation, low cost, and environmental friendliness, providing a practical electrocatalytic water oxidation technology for the effective inactivation of amoebae and their intracellular microorganisms. Overall, this invention has the following advantages:
[0019] (1) No need for excessive external devices, and only cheap and readily available bicarbonate is needed as the electrolyte. Sufficient hydroxyl radicals and carbonate radicals can be generated under low voltage, with low energy consumption.
[0020] (2) On-site treatment, easy and simple operation, efficient inactivation, green and environmentally friendly;
[0021] (3) The size of the electrochemical device can be adjusted to suit various processing scenarios, including micro-scale scenarios. Attached Figure Description
[0022] Figure 1 SEM image (A) and TEM image (B) of bismuth antimonate material;
[0023] Figure 2 A flowchart for electrocatalytic water oxidation to inactivate amoebae protozoan spores, intracellular bacteria of amoebae, and bacteria;
[0024] Figure 3 Flowchart for bismuth antimony-loaded carbon paper;
[0025] Figure 4 The graph shows the inactivation effect of bismuth antimony electrocatalytic water oxidation on amoeba, amoeba endophytes and free amoeba endophytes over time.
[0026] Figure 5 The graph shows the inactivation effect of amoebae spores over time after electrocatalytic water oxidation treatment with antimony tungstate.
[0027] Figure 6 The graph shows the inactivation effect of amoeba spores over time after electrocatalytic water oxidation treatment with bismuth tungstate.
[0028] Figure 7 Scanning electron microscope (SEM) images of amoebae spores before and after water oxidation treatment (A) and transmission electron microscope (TEM) images of amoebae endophytic bacteria (B);
[0029] Figure 8The graph shows the inactivation effect of amoeba, amoeba endophytes and free amoeba endophytes over time after bismuth antimony electrocatalytic water oxidation treatment (A) and the inactivation effect of amoeba under unloaded anode electrocatalytic water oxidation treatment over time (B). Detailed Implementation
[0030] The specific embodiments of the present invention will be further described below. It should be noted that these descriptions are for the purpose of aiding understanding the present invention, but do not constitute a limitation thereof. Furthermore, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.
[0031] Unless otherwise specified, the experimental methods used in the following embodiments are conventional methods, and the experimental materials used in the following embodiments are all available through conventional commercial channels.
[0032] Example 1: Preparation of water oxidation materials
[0033] 1. Synthesis of Bismuth Antimonate
[0034] Nanocrystalline BiSbO4 samples were prepared by hydrothermal method using Bi(NO3)3·5H2O and Sb2O3 as raw materials.
[0035] (1) Add 0.7288g of Sb2O3 powder to 10mL of an aqueous solution containing 2.4254g of Bi(NO3)3·5H2O and stir to mix well. At the same time, adjust the pH of the mixture to 3 with nitric acid solution or sodium hydrate solution while stirring vigorously.
[0036] (2) The obtained mixture was placed into a 25 mL Teflon-lined autoclave and sealed tightly. The autoclave was then placed at 180 °C for hydrothermal treatment for 48 h. After cooling to room temperature, the precipitate was collected and washed several times (usually 3 times) with distilled water and anhydrous ethanol. It was then dried in air at 60 °C to obtain a nano-sized bismuth antimonate sample, denoted as BiSbO4. Figure 1 SEM and TEM showed that the material is at the nanoscale.
[0037] 2. Synthesis of Antimony Tungstate
[0038] (1) Dissolve 1 mmol SbCl3 (0.2281 g) and 0.5 mmol Na2WO4·2H2O (0.1649 g) (2:1 molar ratio) in 10 mL of ethylene glycol (EG) under magnetic stirring. Mix the two solutions in a 50 mL Teflon-lined autoclave, then add 10 mL of distilled water and stir for 30 min.
[0039] (2) Place the autoclave at 160°C for 10 hours, then allow it to cool naturally to room temperature. Collect the precipitate and wash it several times (usually 3 times) with distilled water and anhydrous ethanol. Then dry it in air at 60°C to obtain nano-sized antimony tungstate sample, denoted as Sb2WO6.
[0040] 3. Synthesis of Bismuth Tungstate
[0041] 3.234 g Bi(NO3)3·5H2O and 1.613 g Na2WO4·2H2O were added to 66 mL of pure water and sonicated for 30 min to mix evenly. The mixture was then placed in a 100 mL hydrothermal reactor and hydrothermally reacted at 180 °C for 24 h. After cooling naturally to room temperature, the precipitate was collected and washed several times (usually 3 times) with distilled water and anhydrous ethanol. The precipitate was then dried in air at 60 °C to obtain a nano-sized bismuth tungstate sample, denoted as Bi2WO6.
[0042] Other water-oxidizing materials can also be prepared by a similar hydrothermal method.
[0043] Example 2: A method for electrocatalytic water oxidation to inactivate amoebae protozoan spores, intracellular bacteria of amoebae, and bacteria.
[0044] like Figure 2 As shown, the method includes the following steps:
[0045] (1) Preparation of electrode sheets: Water-oxidizing material and polyvinylidene fluoride (PVDF) were mixed at a mass ratio of 2:1, and an appropriate amount of N-methylpyrrolidone (NMP) liquid was added. The mixture was stirred for 5 minutes to form a non-sticky slurry. The prepared slurry was then drop-coated onto carbon paper and baked in an oven at 150°C for 5 to 10 minutes to prepare the anode electrode sheet. At the same time, nano-zero valent iron was loaded onto carbon paper in the same way to prepare the cathode electrode sheet.
[0046] (2) Set up the electrochemical environment, with the anode being carbon paper loaded with water-oxidizing material (bismuth antimonate). Figure 3 The cathode is carbon paper loaded with nano-zero ferric iron. The electrode sheet is inserted into 50 mL of a solution containing 10... 6In a water sample containing spores of *Dictyostelium discoideum* QS9 (isolated from the field according to the method described in the literature, Brock, DA; Douglas, TE; Queller, DC; Strassmann, JEPrimitive agriculture in a social amoeba. Nature. 2011, 469(7330), 393.), 5 g of potassium bicarbonate was added. After stirring to form a 1 M potassium bicarbonate electrolyte, the water was electrocatalyzed at 3.0 V versus RHE for 4 hours. The stirring speed during the reaction was 300 rpm. The reaction lasted for 4 hours. Samples were taken at 0 min, 15 min, 30 min, 60 min, 120 min, and 240 min, with 1.5 mL taken each time, resulting in 6 water samples (1-6). This experiment was performed in triplicate, resulting in water samples 2-6 and 3-6.
[0047] (3) Take the three groups of water samples obtained in step (1) for amoeba culture. After diluting them with KK2 buffer at a 10-fold gradient, take 100 μL of amoeba suspension or bacterial suspension and spread it on SM / 5 medium (add 2g glucose, 2g bacterial peptone (Oxoid), 2g yeast extract (Oxoid), 0.2g MgCl2, 1.9g KH2PO4, 1g K2HPO4 and 15g agar to 1L double-distilled water, sterilize by high temperature and high pressure steam for 20min, and dispense 20mL of medium into a petri dish on a clean bench) for culture. Each 100 μL of amoeba needs to be mixed with 200 μL of OD 600 =1.5 food bacteria [(Klebsiella pneumoniae Kp, isolated from the method described in the document (Lima, WC; Pillonel, T.; Bertelli, C.; Ifrid, E.; Greub, G.; Cosson, P., Genome sequencing and functional characterization of the non-pathogenic Klebsiella pneumoniae KpGe bacteria. Microbes and Infection 2018, 20, (5), 293-301.)] were mixed and cultured in a constant temperature and light incubator at 21℃ for 60 hours. After that, plaques formed by amoeba predation could be observed on the food bacteria plate. The number of live amoeba cells was obtained by counting the CFU.
[0048] (4) For bacterial counting, the bacteria need to be directly spread on SM / 5 medium and incubated at room temperature. After 2-3 days, clear single colonies can be grown. The bacteria in the amoeba spores need to be broken up using MP tubes containing glass beads. During the breaking up process, the amoeba spores are examined under a microscope until no complete spores are observed in each sample. Then, the serial dilution and bacterial culture are performed in the same way as in step (2). Finally, the number of live bacteria is obtained by counting the CFU.
[0049] (5) Results are as follows Figure 4 As shown, it can be seen that:
[0050] The inactivation rate of amoebae protozoan spores reached nearly 99.9% after 4 hours, the inactivation rate of intracellular amoebae microorganisms reached nearly 99.999% after 2 hours, and bacteria achieved a triple-log inactivation rate after 1 hour. Furthermore, after a period of cultivation, the amoebae protozoan spores did not re-form observable colonies, proving that this method did not inhibit the growth of amoebae spores but achieved complete inactivation.
[0051] Furthermore, the same method was used to investigate the effectiveness of antimony tungstate and bismuth tungstate in electrocatalytic water oxidation to inactivate amoebae protozoan spores and intracellular bacteria of amoebae. For example... Figure 5 , 6 It is shown that using carbon paper loaded with antimony tungstate or bismuth tungstate as the anode can basically guarantee an inactivation effect of 2-3 logs.
[0052] It is evident that the electrocatalytic water oxidation method proposed in this invention for inactivating amoebae protozoan spores and intracellular bacteria of amoebae can effectively inactivate bacteria, amoebae protozoan spores and intracellular bacteria of amoebae, and has a very good disinfection effect in water disinfection.
[0053] Example 3: Observation of the inactivation effect of electrocatalytic water oxidation on amoebae spores and their intracellular microorganisms.
[0054] (1) Set up the electrochemical environment. The anode is carbon paper loaded with bismuth antimony, a water-oxidizing material, and the cathode is carbon paper loaded with nano-zero valent iron. Insert the electrode plates into a solution containing 50 mL of a 10% concentration of... 6 To a water sample containing 1 / mL of amoebae spores, 5g of potassium bicarbonate was added, and the mixture was stirred to form a 1M potassium bicarbonate electrolyte. The water was then electrocatalyzed at 3.0V versus RHE for 4 hours, with a stirring speed of 300 rpm. Samples were taken at 0 min, 15 min, 30 min, 60 min, 120 min, and 240 min, resulting in six water samples (4-6). This experiment was repeated in triplicate, yielding water samples (5-6, 6-6).
[0055] (2) Centrifuge the three groups of biological samples obtained in step (1), collect the precipitate and resuspend it in an isotonic solution of amoebae cells and bacteria (KK2: 0.67g K2HPO4 and 2.25g KH2PO4 dissolved in 1L double-distilled water, sterilized under high temperature and high pressure, cooled to room temperature, and placed in a clean bench for later use) (approximately 1×10⁻⁶). 8 After centrifuging again with 1 mL of amoebae spores (KK2), add enough fixative (2.5% glutaraldehyde) to cover the precipitate along the tube wall, and then fix at 4°C for more than 12 hours. Finally, the images were recorded by scanning electron microscopy (SEM) and transmission electron microscopy (TEM).
[0056] (3) The results are as follows Figure 7 As shown, it can be seen that:
[0057] By comparing SEM images before and after water oxidation, it is clear that before water oxidation, the amoebae spores appeared as capsules with intact outer walls and were generally plump under the scanning electron microscope. After treatment, the outer walls of the amoebae spores ruptured, and some spores had their outer walls sunken. The thick cell membrane of amoebae spores is mainly composed of polysaccharide polymers, and the thick cell wall acts as a strong physical barrier. Among existing amoebae inactivation methods, only some reports indicate that spores can be sunken inward (see the literature "He Z, Zheng N, Zhang L, et al. Efficient inactivation of intracellular bacteria in dormant amoeba spores by FeP[J]. Journal of hazardous materials, 2022(Mar.5):425.DOI:10.1016 / j.jhazmat.2021.127996."), and no spore outer wall damage was observed. Therefore, the method of this invention is the first to utilize advanced oxidation technology to rupture amoebae spores. This demonstrates the powerful disinfection capability of the water oxidation technology of this invention.
[0058] Meanwhile, TEM images of amoebae carrying endosymbiotic bacteria showed that, before treatment, the endosymbiotic bacteria within the amoebae exhibited normal bacterial structure with a black interior, indicating that the bacteria remained active before sample fixation and cutting. After water oxidation disinfection, although the edges of the endosymbiotic bacteria remained black, the central protoplasts appeared white, indicating that the endosymbiotic bacteria had been inactivated. This demonstrates that the method of the present invention can also inactivate microorganisms within amoebae spores by penetrating their cell walls and cell membranes.
[0059] Furthermore, the mechanism by which bismuth antimonate is used as an example to investigate the electrocatalytic water oxidation inactivation of amoebae spores and their intracellular microorganisms:
[0060] The anode loaded with bismuth antimonate and the cathode loaded with nano-zero ferric iron were inserted into 50 mL of a solution containing 10... 6 Add 5g of potassium bicarbonate to the water sample containing 1 / mL of amoebae protozoan spores, stir well to form a 1M potassium bicarbonate electrolyte, and then electrocatalyze the water oxidation reaction at 3.0V versus RHE for 4 hours. The stirring speed during the reaction is 300 rpm, and the reaction lasts for a total of 4 hours. Samples are taken at 0 min, 15 min, 30 min, 60 min, 120 min, and 240 min.
[0061] As a control, the anode without water-oxidizing material and the cathode without nano-zero valent iron were inserted into a solution containing 50 mL of 10... 6 Sodium sulfate was added to a water sample containing 1 / mL of amoebae protozoan spores and stirred until a 1M sodium sulfate electrolyte was formed. The voltage was set to -1.5V (to ensure consistency with the water oxidation current density mentioned above), the working electrode was the cathode, the stirring speed during the reaction was 300 rpm, and the reaction lasted for 4 hours. Samples were taken at 0 min, 15 min, 30 min, 60 min, 120 min, and 240 min.
[0062] Finally, the number of viable amoeba cells and viable bacteria was obtained through CFU (Cellular Fusion Method). Figure 8 The results show that the generation and activation of hydrogen peroxide in the water oxidation system plays a decisive role in the inactivation of amoebae spores and their intracellular bacteria. Therefore, by using bismuth antimony loaded at the anode to initiate the water oxidation reaction, and then utilizing nano-zero-valent iron loaded at the cathode to activate the hydrogen peroxide generated during the water oxidation reaction, the inactivation of amoebae can be more effectively achieved.
[0063] In summary, the electrocatalytic water oxidation method provided by this invention has excellent effects on the inactivation of amoebae spores, intracellular microorganisms of amoebae, and free intracellular bacteria. It is also convenient, quick, energy-saving, environmentally friendly, and produces no secondary pollution, showing great promise for application in the field of water disinfection.
[0064] The embodiments of the present invention have been described in detail above, but the present invention is not limited to the described embodiments. For those skilled in the art, various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and these variations still fall within the protection scope of the present invention.
Claims
1. A method for inactivating the protozoan amoebae and its endophytes by electrocatalytic water oxidation, characterized in that, Using a carbon-based material loaded with water oxidation material as the anode, amoebae and their intracellular microorganisms are inactivated by electrocatalytic water oxidation: First, water oxidation material is loaded onto a carbon-based material to form an anode electrode, and nano-zero-valent iron is loaded onto a carbon-based material to form a cathode electrode. Then, the anode and cathode electrodes are inserted into water containing amoebae, bicarbonate electrolyte is added, and electricity is applied. In this way, amoebae and their intracellular microorganisms are inactivated by generating strong oxidizing substances. The water-oxidizing material includes bismuth antimonate, antimony tungstate, and bismuth tungstate, which are prepared by a hydrothermal method.
2. The method for inactivating the protozoan amoebae and its endophytes by electrocatalytic water oxidation according to claim 1, characterized in that, The power-on time is more than 2 hours.
3. The method for inactivating the protozoan amoebae and its endophytes by electrocatalytic water oxidation according to claim 1, characterized in that, The concentration of the bicarbonate electrolyte is 0.5 M-3 M.
4. The method for inactivating the protozoan amoebae and its endophytes by electrocatalytic water oxidation according to claim 1, characterized in that, The voltage applied is controlled between 2.7 and 4 V relative to the reversible hydrogen electrode.
5. The method for inactivating the protozoan amoebae and its endophytes by electrocatalytic water oxidation according to claim 1, characterized in that, Stirring is performed during the power-on process, with a stirring speed of 100-1000 rpm.
6. The method for inactivating the protozoan amoebae and its endophytes by electrocatalytic water oxidation according to claim 1, characterized in that, The hydrothermal method for preparing bismuth antimonate is as follows: Sb2O3 and Bi(NO3)3·5H2O are dissolved in water, the pH is adjusted, and the mixture is subjected to a hydrothermal reaction at 170-190 ℃ for 40-50 h. Finally, the precipitate is collected, washed, and dried to obtain the final product.
7. The method for inactivating the protozoan amoebae and its endophytes by electrocatalytic water oxidation according to claim 1, characterized in that, The hydrothermal method for preparing antimony tungstate is as follows: SbCl3 and Na2WO4·2H2O are dissolved in ethylene glycol, and then subjected to a hydrothermal reaction at 150-170 °C for 7-13 h. Finally, the precipitate is collected, washed, and dried to obtain the final product.
8. The method for inactivating the protozoan amoebae and its endophytes by electrocatalytic water oxidation according to claim 1, characterized in that, The hydrothermal method for preparing bismuth tungstate is as follows: Bi(NO3)3·5H2O and Na2WO4·2H2O are dissolved in water, and then subjected to hydrothermal reaction at 170-190℃ for 20-30 hours. Finally, the precipitate is collected, washed, and dried to obtain the final product.