Device for gas sterilization and sterilization method

Abstract

The application provides a device and a disinfection method for gas disinfection, the device comprising: a mixing unit provided with an aerosol inlet, a carrier gas inlet, and a mixture outlet; a disinfection unit provided with a gas inlet and a gas outlet, the gas inlet being connected with the mixture outlet, the disinfection unit comprising at least one set of disinfection electrode groups with a non-zero included angle with the gas flow direction, each disinfection electrode group comprising two layers of oppositely arranged porous metal meshes, the two layers of porous metal meshes in each disinfection electrode group being connected with a positive electrode of an external power supply and a negative electrode of the external power supply respectively, and the surface of the porous metal mesh being provided with nanowires. Thus, the device can realize efficient, non-toxic and low-cost gas disinfection, and the disinfection electrode groups can significantly prolong the effective disinfection time of the gas disinfection and further improve the disinfection effect of the gas disinfection.

Description

Technical Field

[0001] This invention belongs to the field of gas disinfection technology, specifically relating to a device and method for gas disinfection. Background Technology

[0002] In recent years, the safety risks posed by airborne pathogens have received increasing attention. Air is an unfavorable carrier for microbial survival, but it is highly conducive to the spread and transfer of microorganisms. Small-diameter airborne microbial aerosols can enter the human lungs through respiration, easily impacting human health and safety.

[0003] Gas disinfection aims to control the microbial community in the air and is one of the important means of preventing aerosol-borne diseases. It is also widely used in the medical and food industries, and is of great significance to human health and food safety. Traditional gas disinfection technologies include filtration, ultraviolet irradiation, ozone advanced oxidation, and spraying disinfectants. These disinfection technologies all have some shortcomings, mainly in that disinfection and disinfection byproducts can have adverse effects on human health. For example, filtration disinfection can lead to the enrichment of pathogenic microorganisms, posing a higher risk of secondary infection, and requires further treatment of the filter membrane; although ultraviolet irradiation disinfection is highly efficient and produces fewer byproducts, it suffers from problems such as high energy consumption and photoreactivation of microorganisms.

[0004] Existing technologies propose a method for electrochemical disinfection of wastewater, specifically using porous conductive materials as internal filtration electrodes to improve the mass transfer and direct oxidation disinfection capabilities of the disinfection system, achieving efficient inactivation of microorganisms at low voltage. However, there are significant differences between wastewater disinfection and gas disinfection, which can be summarized as follows: (1) Wastewater has good conductivity, making it easy to transmit current, while air has poor conductivity. To achieve a similar effect, a very high voltage is generally required to break down the air, which poses a significant safety hazard; (2) Microorganisms in wastewater generally carry an electric charge, so they are easily deflected towards the electrode area by electrostatic forces and thus come into contact with the effective disinfection area, while microorganisms in the air are generally electrically neutral, making it difficult for them to come into contact with the effective disinfection area; (3) Wastewater has a lower flow rate, while air flow rate is generally tens or even hundreds of times higher than that of wastewater, which further increases the difficulty for microorganisms to come into contact with the effective disinfection area.

[0005] Therefore, there is an urgent need to propose an efficient, non-toxic, and low-cost gas disinfection device and method to solve at least one of the above-mentioned technical problems. Summary of the Invention

[0006] This invention aims to at least partially solve one of the technical problems in related technologies. Therefore, the object of this invention is to provide a device and method for gas disinfection. Thus, the above-mentioned device achieves efficient, non-toxic, and low-cost gas disinfection, and by setting up a disinfection electrode group, the effective disinfection time of the gas is significantly increased, further improving the disinfection effect.

[0007] In one aspect of the invention, an apparatus for gas sterilization is provided. According to an embodiment of the invention, it includes: a mixing unit having an aerosol inlet, a carrier gas inlet, and a mixture outlet; and a sterilization unit having a gas inlet and a gas outlet, the gas inlet being connected to the mixture outlet. The sterilization unit includes at least one set of sterilization electrodes arranged at a non-zero angle to the gas flow direction. Each sterilization electrode set includes two opposing layers of porous metal mesh, the two layers of porous metal mesh being respectively connected to the positive and negative terminals of an external power supply. The surface of the porous metal mesh has nanowires.

[0008] According to the apparatus of this invention, aerosol and carrier gas are thoroughly mixed in a mixing unit and then output to a sterilization unit. When the mixture formed by the aerosol and carrier gas passes through the sterilization electrode group, a strong electric field is generated at the tips of the nanowires loaded on the sterilization electrode group. This strong electric field causes electroporation on the surface of microbial cells, leading to microbial death and thus completing sterilization. By setting at least one set of sterilization electrode groups with a non-zero angle to the gas flow direction, a multi-layer filtration effect can be achieved. The effective sterilization time for gas sterilization is the sum of the multi-layer filtration times, thereby significantly increasing the effective sterilization time and further improving the sterilization effect. Therefore, the above-described apparatus achieves efficient, non-toxic, and low-cost gas sterilization, and the effective sterilization time is significantly increased by setting the sterilization electrode group, further improving the sterilization effect.

[0009] In addition, the apparatus according to the above embodiments of the present invention may also have the following additional technical features:

[0010] In an embodiment of the present invention, the surface of the nanowire is coated with a conductive film layer. Therefore, by providing a conductive film layer, corrosion and wear of the nanowire can be reduced, thereby improving the service life of the nanowire.

[0011] In an embodiment of the present invention, the aspect ratio of the nanowire is (50-100):1, which is beneficial to enhance the strong electric field formed at the tip of the nanowire and thus improve the disinfection effect.

[0012] In embodiments of the present invention, the nanowire material includes at least one selected from CuO, Cu(OH)2, Fe3O4, Co3O4, Ag, TiO2, and ZnO. This further improves the disinfection effect of gas sterilization.

[0013] In embodiments of the present invention, the preparation methods of the nanowires include thermal oxidation, electrochemical methods, and wet chemical methods. Therefore, nanowires prepared by the above methods can further improve the disinfection effect of gas sterilization.

[0014] In embodiments of the present invention, the material of the conductive film layer includes poly(3,4-ethylenedioxyphene)-poly(olefin sulfonic acid). This further improves the disinfection effect of gas sterilization and also further extends the lifespan of the nanowires.

[0015] In an embodiment of the present invention, the thickness of the conductive film layer is 30 nm to 50 nm. This further improves the sterilization effect of gas disinfection and also extends the lifespan of the nanowires.

[0016] In an embodiment of the present invention, the carrier gas inlet includes a plurality of arrayed gas distribution holes. This allows for thorough mixing of the aerosol and the carrier gas, ensuring full contact between the microorganisms in the aerosol and the tip regions of the nanowires.

[0017] In an embodiment of the present invention, the aerosol inlet and the mixer outlet are connected by a hollow pipe, and the ratio of the length to the diameter of the hollow pipe is greater than or equal to 4:1. This further ensures thorough mixing of the aerosol and the carrier gas, thereby further improving the disinfection effect of the gas sterilization.

[0018] In an embodiment of the present invention, the angle between the gas flow direction and the disinfection electrode assembly is a right angle. This further improves the gas disinfection effect.

[0019] In embodiments of the present invention, an insulating mesh is provided between adjacent porous metal meshes. Therefore, by providing the insulating mesh, contact between adjacent porous metal meshes can be avoided, thereby preventing short circuits in the aforementioned device.

[0020] In an embodiment of the present invention, the vertical distance between adjacent porous metal meshes is 1mm to 2mm. This reduces the size of the device and further improves the gas sterilization effect.

[0021] In embodiments of the present invention, the number of disinfection electrode groups in the disinfection unit is 4 to 12. This reduces the size of the device and further improves the gas disinfection effect.

[0022] In an embodiment of the present invention, the voltage between the positive and negative terminals of the external power supply is 5V to 50V. Therefore, gas sterilization can be achieved with a relatively small voltage.

[0023] In embodiments of the present invention, the insulating mesh includes at least one of a plastic mesh and a nylon mesh. This further prevents short circuits in the aforementioned device.

[0024] In an embodiment of the present invention, the porous metal mesh comprises a porous copper mesh. This further increases the effective disinfection time for gas sterilization.

[0025] In another aspect, the present invention provides a method for disinfection using the apparatus described in the above embodiments. According to an embodiment of the present invention, the method includes:

[0026] Aerosol and carrier gas are introduced into a mixing unit for mixing to obtain a mixture;

[0027] The mixture is introduced into the sterilization unit and passes through the sterilization electrode assembly to achieve gas sterilization.

[0028] According to an embodiment of the present invention, a method for gas disinfection involves introducing aerosol and carrier gas into a mixing unit to obtain a mixture. When the mixture passes through a disinfection electrode assembly, the tips of nanowires loaded on the electrode assembly generate a strong electric field. This strong electric field causes electroporation on the surface of microbial cells, leading to microbial death and thus disinfection of the mixture. By setting at least one set of disinfection electrode assemblies with a non-zero angle to the gas flow direction, a multi-layer filtration effect can be achieved. The effective disinfection time for the gas is the sum of the multi-layer filtration times, significantly increasing the effective disinfection time and further improving the disinfection effect. Therefore, the entire disinfection process takes very little time, achieving highly efficient gas disinfection through a single internal filtration. This disinfection process produces almost no disinfection byproducts and has low energy consumption, making it promising for future applications in ventilation ducts, cold storage, humidifiers, and other similar scenarios.

[0029] In addition, the method according to the above embodiments of the present invention may also have the following additional technical features:

[0030] In embodiments of the present invention, the humidity of the mixture is 40% to 100%. This improves the conductivity of the mixture, making it easier for the mixture to come into contact with the effective disinfection area.

[0031] In an embodiment of the present invention, the flow rate ratio of the aerosol to the carrier gas is (2-12):3. This allows the mixture to more easily reach the effective disinfection area and also improves the removal efficiency of microorganisms in the aerosol.

[0032] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0033] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0034] Figure 1 This is a schematic diagram of the structure of a gas sterilization device according to some embodiments of the present invention;

[0035] Figure 2 This is a schematic diagram of the structure of the flow-carrying gas outlet in some embodiments of the present invention;

[0036] Figure 3 These are schematic diagrams of the porous metal mesh structure according to some embodiments of the present invention;

[0037] Figure 4 This is a flowchart of a method for disinfection using the above-described apparatus according to some embodiments of the present invention;

[0038] Figure 5 This is a scanning electron microscope image of Cu(OH)2 nanowires from Example 1;

[0039] Figure 6 This is a diagram illustrating the disinfection effect on various microorganisms at 100% relative humidity in Example 1.

[0040] Figure 7 This is a diagram showing the coating effect of Cu(OH)2 nanowires in Example 2. Figure 7 (a) is a transmission electron microscope (TEM) image of the coated Cu(OH)₂ nanowires. Figure 7 (b) is the elemental analysis diagram of the coated Cu(OH)2 nanowires;

[0041] Figure 8 The image shows the disinfection effects of 100% and 40% relative humidity on various microorganisms in Example 2.

[0042] Figure label:

[0043] 110 - Aerosol inlet; 120 - Carrier gas inlet; 130 - Carrier gas outlet; 210 - Sterilization electrode assembly; 220 - Fixing element and 230 - Sealing element. Detailed Implementation

[0044] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0045] In one aspect of the invention, an apparatus for gas sterilization is provided. According to an embodiment of the invention, reference is made to... Figure 1 and Figure 3 The aforementioned device includes: a mixing unit, which has an aerosol inlet 110, a carrier gas inlet 120, and a mixture outlet; and a sterilization unit, which has a gas inlet and a gas outlet, with the gas inlet connected to the mixture outlet. The sterilization unit includes at least one set of sterilization electrode groups 210 that form a non-zero angle with the gas flow direction. Each sterilization electrode group 210 includes two layers of porous metal mesh arranged opposite each other. The two layers of porous metal mesh within the sterilization electrode group 210 are respectively connected to the positive and negative terminals of an external power supply. The surface of the porous metal mesh has nanowires. Therefore, this device achieves efficient, non-toxic, and low-cost gas sterilization. By incorporating porous metal mesh, the effective sterilization time of the gas is significantly increased, further enhancing the sterilization effect.

[0046] The following provides a detailed explanation of how the aforementioned device can achieve the above-mentioned technical effects. (Refer to...) Figure 1 and Figure 3 :

[0047] Aerosol is introduced into the mixing unit through aerosol inlet 110, and carrier gas is introduced into the mixing unit through carrier gas inlet 120. The aerosol and carrier gas are thoroughly mixed in the mixing unit. The mixture formed by the aerosol and carrier gas enters the disinfection unit from the gas outlet. When the power is turned on, when the mixture formed by the aerosol and carrier gas passes through the disinfection electrode group 210, a strong electric field is formed at the tip of the nanowire loaded on the disinfection electrode group 210. The strong electric field causes electroporation on the surface of microbial cells, leading to the death of microorganisms, thereby completing the disinfection. Due to the high flow rate of the aerosol, it is necessary to maximize the effective disinfection time to achieve efficient gas disinfection. The aerosol will cause electroporation in the tip region of the nanowire. By setting at least one set of disinfection electrode groups 210 with a non-zero angle to the gas flow direction, a multi-layer filtration effect can be achieved. The effective disinfection time of gas disinfection is the sum of the multi-layer filtration times, which significantly increases the effective disinfection time of gas disinfection and further improves the disinfection effect of gas disinfection. If porous foam metal, porous ceramic, or porous sponge is used as the sterilization electrode assembly, the sterilization time needs to be calculated based on the thickness of the electrode assembly material. The nanowire tip region, where electroporation can occur, is relatively small, leading to a significant reduction in the effective sterilization time and thus affecting the sterilization effect. It is important to note that the entire gas sterilization device must be kept sealed. This can be achieved by using fasteners 220 (such as bolts) to secure the mixing and sterilization units, and by using sealants 230 (such as sealant) for sealing.

[0048] Furthermore, porous metal meshes include, but are not limited to, porous copper meshes. Porous copper meshes have good electrical conductivity, which is beneficial to improving the tip discharge effect of nanowires, thereby improving the disinfection effect of gas sterilization.

[0049] Furthermore, nanowires were chosen because: to achieve the irreversible electroporation effect, a very large pulse voltage (>1kV) is generally required. Nanowires can achieve a localized strong electric field through the tip discharge effect. When a low voltage is applied by the power supply, although the average electric field strength between the electrodes is very low, the electric field near the tip of the nanowire is sufficient to achieve irreversible electroporation, thus avoiding the safety hazards caused by excessive power supply voltage. In addition, the area where air is effectively disinfected is only a portion of the nanowire tip. Given a fixed device size, using wires that are too large will reduce the effective disinfection area. At the same time, wires that are too large are also not conducive to preparation and installation.

[0050] In some embodiments, the surface of the nanowires is coated with a conductive film layer. By setting a conductive film layer, the disinfection effect and the service life of the nanowires can be significantly improved. Specifically, (1) a metal (such as silver) that has an inhibitory effect on bacteria can be introduced into the conductive film layer to play an auxiliary role in disinfection; (2) catalytically active substances (such as ZnO, CoO, TiO, etc.) can be introduced into the conductive film layer to enhance the electrochemical process and thus improve the disinfection effect; (3) the conductivity and capacitance of the disinfection electrode assembly 210 can be enhanced, and the strong electric field formed at the tip of the nanowire can be strengthened to improve the disinfection effect. At the same time, by setting a conductive film layer, the service life of the nanowires can also be improved, including: (1) a conductive film layer that is not easily reactive can be set to improve the resistance of the nanowires to electrochemical corrosion; (2) by setting a conductive film layer, the mechanical strength of the nanowires can be enhanced, and the loss of the nanowires caused by fluid scouring can be reduced. It should be noted that during the disinfection process, the above-mentioned device should be in a sealed state to avoid the influence of external gas on the disinfection process. It should be noted that without a conductive film coating the nanowires, gas sterilization can only be effectively performed under high humidity conditions. If the humidity is too low, the conductivity of the microorganisms in the device is poor, making it difficult for them to reach the effective sterilization area, significantly reducing the sterilization effect or even preventing the process from being completed. By coating the nanowires with a conductive film, gas sterilization can be effectively performed even at lower humidity levels. Therefore, by incorporating a conductive film, the application scenarios of the aforementioned device can be significantly expanded.

[0051] Furthermore, the conductive film layer is made of poly(3,4-ethylenedioxyphene)-poly(olefin sulfonic acid), and the nanowires are impregnated with the commercially available material PEDOT:PSS to form poly(3,4-ethylenedioxyphene)-poly(olefin sulfonic acid) on the surface of the nanowires. This further improves the disinfection effect of gas sterilization and extends the lifespan of the nanowires. Specifically, on one hand, the organic film layer of the poly(3,4-ethylenedioxyphene)-poly(olefin sulfonic acid) material contains sulfonic acid groups. By coating the nanowires with this organic film layer, the conductivity of the nanowires can be significantly improved, enhancing the conductivity and capacitance of the sterilization electrode assembly 210, strengthening the strong electric field formed at the tip of the nanowires, and thus improving the disinfection effect. On the other hand, the organic film layer of the poly(3,4-ethylenedioxyphene)-poly(olefin sulfonic acid) material is an inert organic polymer film layer, which can improve the nanowires' resistance to electrochemical corrosion, enhance their mechanical strength, and reduce nanowire loss due to fluid erosion. Furthermore, PEDOT:PSS material is relatively inexpensive and readily available, which is beneficial for industrial production. The conductive film layer has a thickness of 30nm to 50nm. This avoids the problem of an excessively thick conductive film layer, which would result in an excessively large diameter of the nanowires, reducing their aspect ratio and severely affecting the tip discharge effect, thus significantly impacting the gas sterilization efficiency. Conversely, an excessively thin conductive film layer would make it difficult to control the uniformity of the conductive film, also affecting the gas sterilization efficiency.

[0052] In some embodiments, the nanowire material includes at least one of CuO, Cu(OH)2, Fe3O4, Co3O4, Ag, TiO2 and ZnO nanowires, preferably at least one of CuO and Cu(OH)2, thereby further improving the disinfection effect of gas sterilization.

[0053] Furthermore, the preparation methods for nanowires include thermal oxidation, electrochemical methods, and wet chemical methods. Specifically, the thermal oxidation method (taking the preparation of CuO nanowires as an example) includes the following steps: cleaning the copper material with dilute hydrochloric acid to remove the oxide film on the surface of the copper material; washing the copper material repeatedly with deionized water and drying it with dry nitrogen gas; and calcining the copper material in a tube furnace at a temperature of 400℃-600℃ for 1.5h-2.5h to obtain CuO nanowires. The electrochemical method (taking the preparation of Cu(OH)2 nanowires as an example) includes the following steps: cleaning the copper material with dilute hydrochloric acid to remove the oxide film on the surface of the copper material. The process involves several steps: 1) Washing the copper material repeatedly with deionized water; 2) Immersing the copper material in a sodium hydroxide solution, connecting it to an external DC power supply, with the anode connected to the copper material and the cathode connected to an inert electrode, reacting at room temperature, and then washing and drying to obtain Cu(OH)₂ nanowires. The electrochemical method (taking Cu(OH)₂ nanowire preparation as an example) includes: cleaning the copper material with dilute hydrochloric acid to remove the oxide film on the copper surface; washing the copper material repeatedly with deionized water; mixing the copper material, ammonium persulfate, and sodium hydroxide for 0.5-1.0 h; and then washing and drying to obtain Cu(OH)₂ nanowires. It should be noted that since the morphology of nanowires greatly affects the gas sterilization effect, electron microscopy can be used to characterize the morphology of the nanowires after preparation. The specific steps for electron microscopy sample preparation and observation include: taking a small piece of the prepared nanowire, adhering the nanowire to conductive adhesive, and directly observing it under a scanning electron microscope to screen for nanowires with better morphology.

[0054] Furthermore, the aspect ratio of the nanowire is (50-100):1. As an example, the aspect ratio of the nanowire is 50:1, 60:1, 70:1, 80:1, 90:1 or 100:1, etc. This avoids both the nanowire having too small an aspect ratio, which would result in insufficient tip discharge effect, and the nanowire having too large an aspect ratio, which would make it easy to break and difficult to carry out practical operation.

[0055] In some embodiments, reference is made to Figure 2 The carrier gas inlet 120 includes multiple arrayed air holes. By setting the carrier gas inlet 120 as multiple arrayed air holes, the aerosol and carrier gas can be fully mixed, ensuring that the microorganisms in the aerosol and the tip area of ​​the nanowires are in full contact, thereby improving the disinfection effect of gas disinfection.

[0056] Further, refer to Figure 1 By setting the aerosol outlet and the carrier gas outlet 130 to be parallel, the aerosol and the carrier gas can be fully mixed, ensuring that the microorganisms in the aerosol and the tip area of ​​the nanowires are in full contact, thereby improving the disinfection effect of gas disinfection.

[0057] In some embodiments, reference is made to Figure 1 The aerosol inlet 110 is connected to the mixer outlet via a hollow pipe. The ratio of the length to the diameter of the hollow pipe is greater than or equal to 4:1. This allows for thorough mixing of the aerosol and the carrier gas, ensuring sufficient contact between the microorganisms in the aerosol and the tip regions of the nanowires, thereby improving the disinfection effect of the gas sterilization. The length and diameter of the hollow pipe are not specifically limited and can be selected by those skilled in the art based on actual conditions.

[0058] In some embodiments, the vertical distance between adjacent porous metal meshes is 1mm to 2mm. As an example, the vertical distance between adjacent porous metal meshes is 1mm, 1.2mm, 1.4mm, 1.6mm, 1.8mm, or 2mm, etc. Therefore, since the diameter of the nanowires is very small, controlling the vertical distance between adjacent porous metal meshes within the above range can, on the one hand, reduce the installation area of ​​the disinfection unit and the size of the device while ensuring good gas disinfection effect and circuit safety. On the other hand, within a limited area, more disinfection electrode groups 210 can be set, increasing the effective disinfection area and further improving the gas disinfection effect.

[0059] Furthermore, the number of disinfection electrode groups 210 in the disinfection unit is 4 to 12. As an example, the number of disinfection electrode groups 210 in the disinfection unit can be 4, 5, 6, 7, 8, 9, 10, 11 or 12. Thus, while ensuring good gas disinfection effect and circuit safety, the installation area of ​​the disinfection unit can be reduced, and the size of the above-mentioned device can be reduced.

[0060] Furthermore, an insulating mesh is provided between adjacent porous metal meshes. Thus, by providing the insulating mesh, contact between adjacent porous metal meshes can be avoided, thereby preventing short circuits in the aforementioned device.

[0061] Optionally, the insulating mesh includes, but is not limited to, at least one of plastic mesh and nylon mesh.

[0062] In some embodiments, the voltage between the positive and negative terminals of the external power supply is 5V to 50V. As an example, the voltage between the positive and negative terminals of the external power supply can be 5V, 10V, 15V, 20V, 25V, 30V, 35V, 40V, 45V, or 50V, etc. Thus, gas sterilization can be achieved with a relatively small voltage, without the need for an extremely large voltage to break down the air, thus avoiding potential safety hazards.

[0063] In another aspect of the invention, a method for disinfection using the apparatus described in the above embodiments is proposed. According to an embodiment of the invention, reference is made to... Figure 4 ,include:

[0064] S100: Introduce aerosol and carrier gas into the mixing unit to mix and obtain a mixture.

[0065] In this step, aerosol and carrier gas are introduced into a mixing unit for mixing to obtain a mixture.

[0066] In some embodiments, the humidity of the mixture is 40%–100%. As an example, the humidity of the mixture can be 40%, 50%, 60%, 70%, 80%, 90%, or 100%. Since airborne microorganisms are generally electrically neutral, they do not easily come into contact with the effective disinfection area. Controlling the humidity of the mixture within the above range can improve the conductivity of the aerosol, making it easier for microorganisms in the mixture to come into contact with the effective disinfection area. This significantly increases the effective disinfection time of gas disinfection and further improves the disinfection effect. Methods for controlling the humidity of the mixture include, but are not limited to, adjusting the humidity, flow rate, and velocity of the aerosol and carrier gas to ensure that the mixed mixture has the desired humidity. The specific adjustment operations can be selected according to the actual situation, as long as the humidity of the mixture is maintained at 40%–100%.

[0067] In some embodiments, the flow rate ratio of aerosol to carrier gas is (2-12):3. As an example, the flow rate ratio of aerosol to carrier gas can be 2:3, 4:3, 6:3, 8:3, 10:3, or 12:3, etc. Therefore, controlling the flow rate ratio of aerosol to carrier gas within the above range ensures that the mixture obtained by mixing the aerosol and carrier gas has the expected humidity and good conductivity, making it easier for microorganisms in the mixture to come into contact with the effective disinfection area, thereby improving the removal efficiency of microorganisms in the aerosol.

[0068] In some embodiments, the aerosol flow rate is 2 L / min to 4 L / min, and the carrier gas flow rate is 1 L / min to 3 L / min. For example, the aerosol flow rate can be 2 L / min, 2.5 L / min, 3 L / min, 3.5 L / min, or 4 L / min, and the carrier gas flow rate can be 1 L / min, 1.5 L / min, 2 L / min, 2.5 L / min, or 3 L / min. Therefore, controlling the aerosol and carrier gas flow rates within these ranges facilitates thorough mixing of the aerosol and carrier gas, ensuring sufficient contact between the microorganisms in the aerosol and the tip regions of the nanowires, thereby improving the disinfection effect of gas sterilization. It also avoids excessively slow aerosol and carrier gas flow rates, which would significantly prolong the disinfection time.

[0069] S200: The mixture is introduced into the disinfection unit for disinfection.

[0070] In this step, the mixture is introduced into the sterilization unit and passes through two layers of opposing porous metal mesh to achieve sterilization. When the mixture passes through the sterilization electrode assembly, the tips of the nanowires loaded on the electrode assembly generate a strong electric field. This strong electric field causes electroporation on the surface of microbial cells, leading to microbial death and thus sterilization. By setting at least one set of sterilization electrode assemblies with a non-zero angle to the gas flow direction, a multi-layer filtration effect can be achieved. The effective sterilization time for the gas is the sum of the filtration times of the multiple layers, significantly increasing the effective sterilization time and further improving the sterilization effect. The entire sterilization process takes very little time, achieving highly efficient gas sterilization through a single internal filtration. This sterilization process produces almost no sterilization byproducts and has low energy consumption, making it promising for future applications in ventilation ducts, cold storage, humidifiers, and other scenarios.

[0071] In some embodiments, step S200 further includes testing the disinfected mixture to evaluate the disinfection effect. Specifically, the testing method is gas impaction sampling, using an air sampler to collect samples of the mixture before and after disinfection onto a microbial culture plate. The volume of gas collected each time is the same, and the process is repeated at least three times. Subsequently, the plate is incubated under suitable conditions, the microbial community on the plate is counted, and the disinfection effect is calculated using the following formula:

[0072]

[0073]

[0074] This allows for a more accurate assessment of the disinfection effect of gas disinfection.

[0075] The embodiments of the present invention are described in detail below. It should be noted that the embodiments described below are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention. In addition, unless otherwise specified, all reagents used in the following embodiments are commercially available or can be synthesized according to the methods described herein or known to others. For reaction conditions not listed, they are also readily available to those skilled in the art.

[0076] Example 1

[0077] This embodiment proposes a disinfection method, including the following steps:

[0078] (1) Preparation of disinfection unit

[0079] (1-1) Select porous metal mesh

[0080] In this embodiment, the porous metal mesh selected is a 100-mesh copper mesh with a diameter of 5cm;

[0081] (1-2) Electrochemical preparation of nanowires

[0082] The copper material was cleaned with 1 mol / L dilute hydrochloric acid for 3 min to remove the surface oxide film; it was then washed three times with deionized water; the copper material was immersed in 1.5 mol / L sodium hydroxide solution, and an external DC power supply was connected, with the anode connected to the copper material and the cathode connected to the inert electrode. The current was adjusted to a constant 75 mA, and the reaction was carried out at room temperature for 25 min; the electrode was washed three times with deionized water and dried at room temperature to prepare Cu(OH)2 nanowires.

[0083] (1-3) Characterizing the morphology of nanowires using electron microscopy

[0084] A small piece of the prepared coated Cu(OH)₂ nanowire was taken, adhered to a conductive adhesive, and observed directly under a scanning electron microscope; the scanning electron microscope image is as follows. Figure 5 As shown, the average length of the nanowires is 12.0 ± 2.3 μm, and the average diameter is 0.32 ± 0.10 μm.

[0085] (2) Construct and operate a device for gas sterilization.

[0086] (2-1) Construct a device for gas sterilization

[0087] The aforementioned device comprises, in sequence, an aerosol generator, a mixing unit, and a sterilization unit, as shown in the reference. Figure 1 The above-mentioned device is made of transparent acrylic. The mixing unit and the disinfection unit are integrally molded into a hollow metal pipe, and the airflow can flow freely and continuously along the pipe. The inner diameter of the hollow metal pipe is 5cm, and the length of the mixing section of the hollow metal pipe is 20cm. The entire device is sealed with sealant to prevent air leakage from the side of the pipe.

[0088] (2-2) Mounting nanowire-modified three-dimensional electrodes

[0089] Place the aerosol disinfection device (pipeline) horizontally. Two layers of porous metal mesh arranged opposite each other form a group, which are connected to the positive and negative terminals of the power supply respectively. The distance between the two porous metal meshes is 2mm, and a nylon mesh is used to separate them to prevent short circuits. Install the disinfection electrode group in the position facing the airflow direction. There are four sets of electrodes installed in the device, forming a multi-layer internal filtration mode.

[0090] (2-3) Gas-related parameters of the regulating device

[0091] The carrier gas was introduced into the mixing unit at a flow rate of 2 L / min, and the aerosol was introduced into the mixing unit at a flow rate of 4 L / min. The relative humidity inside the device was adjusted to 100%, and the microbial concentration was 10. 3 CFU / m 3After the device has been running continuously for 3 minutes and the internal aerosol system has stabilized, DC voltages of 5V, 15V, 30V, and 50V are applied to the disinfection electrode group for disinfection.

[0092] Step 3: Air sampling and testing to assess the disinfection effect. The specific methods and calculation formulas are as follows:

[0093] The targets of gas disinfection were atomized laboratory-cultured microorganisms, including *Escherichia coli*, *Enterococcus faecalis*, *Bacillus subtilis* spores, MS2 bacteriophage, and Phi6 bacteriophage. The corresponding microorganisms were cultured and detected according to the methods in Table 1. The detection method was air impaction sampling. An air sampler was used to collect the mixture before and after disinfection onto microbial culture plates. The volume of gas collected each time was the same, and the samples were repeated three times in parallel. The plates were then incubated under suitable conditions, and the microbial communities on the plates were counted. The disinfection effect was calculated using the following formula:

[0094]

[0095]

[0096] Final disinfection effect as Figure 6 As shown, under the condition of a processing time of 0.3 s and a relative humidity of 100%, the inactivation rate of Escherichia coli reached 85%, the inactivation rate of Enterococcus faecalis reached 65%, the inactivation rate of Bacillus spores reached 70%, and the inactivation rate of the two bacteriophages reached >2-log.

[0097] Table 1. Microbial culture and detection methods

[0098]

[0099] Example 2

[0100] This embodiment proposes a disinfection method. The only difference between this embodiment and Embodiment 1 is that:

[0101] (1-2) Prepare a 0.1 g / L PEDOT:PSS solution, immerse the prepared Cu(OH)₂ nanowires in the PEDOT:PSS solution for 1 min, then remove and dry them. Repeat the immersion coating three times. After coating, the average diameter of the Cu(OH)₂ nanowires is 300 nm, and the average thickness of the poly(3,4-ethylenedioxyphene)-poly(olefin sulfonic acid) film is 32 nm. (Reference) Figure 7 Thus, coated Cu(OH)2 nanowires were obtained;

[0102] (2-3) The relative humidity inside the regulating device is 40% and 100%;

[0103] The rest of the parts are consistent with Example 1.

[0104] Final disinfection effect as Figure 8 As shown, under the condition of a processing time of 0.3s, when the relative humidity is 40%, the inactivation rate of Escherichia coli reaches 51% and the inactivation rate of Enterococcus faecalis reaches 33%; when the relative humidity is 100%, the inactivation rates of the two bacteria reach approximately 70% and 60%, respectively. Therefore, by setting a conductive film layer, the application scenarios of the above-mentioned device can be greatly increased.

[0105] Example 3

[0106] This embodiment proposes a disinfection method. The only difference between this embodiment and Embodiment 2 is that:

[0107] (1-2) The average thickness of the poly(3,4-ethylenedioxyphene)-poly(olefin sulfonic acid) film is 50 nm, thereby obtaining coated Cu(OH)2 nanowires;

[0108] (2-3) The relative humidity inside the regulating device is 40% and 100%;

[0109] The rest of the parts are consistent with Example 2.

[0110] Under the condition of a processing time of 0.3s, when the relative humidity is 40%, the inactivation rate of Escherichia coli and Enterococcus faecalis is close to that of Example 2; when the relative humidity is 100%, the inactivation rate of the two bacteria is close to that of Example 2. Therefore, by setting a conductive film layer, the application scenarios of the above-mentioned device can be greatly increased.

[0111] Analysis of Examples 1-3 shows that the gas disinfection device described above has a good effect on gas disinfection. The entire disinfection process produces almost no disinfection byproducts. By setting a conductive film layer, the application scenarios of the above device can be greatly increased.

[0112] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A method for disinfection using an apparatus for gas sterilization, characterized in that, include: The device for gas sterilization includes: A mixing unit, wherein the mixing unit is provided with an aerosol inlet, a carrier gas inlet, and a mixture outlet; A disinfection unit has a gas inlet and a gas outlet, the gas inlet being connected to the mixture outlet. The disinfection unit includes at least one set of disinfection electrodes positioned at a non-zero angle to the gas flow direction. Each disinfection electrode set comprises two opposing porous metal mesh layers, each connected to the positive and negative terminals of an external power supply, respectively. The surface of the porous metal mesh has nanowires. Aerosol and carrier gas are introduced into a mixing unit for mixing to obtain a mixture. The mixture is then introduced into the disinfection unit, passing through the disinfection electrode sets to achieve gas disinfection. The humidity of the mixture is 40%–100%. The surface of the nanowires is coated with a conductive film layer. The conductive film layer meets the following conditions: the material of the conductive film layer includes poly(3,4-ethylenedioxyphene)-poly(olefin sulfonic acid); the thickness of the conductive film layer is 30 nm–50 nm.

2. The method according to claim 1, characterized in that, The nanowires satisfy at least one of the following conditions: The aspect ratio of the nanowire is (50~100):1; The nanowires include at least one of CuO, Cu(OH)2, Fe3O4, Co3O4, Ag, TiO2, and ZnO; The nanowires are prepared by thermal oxidation, electrochemical methods, and wet chemical methods.

3. The method according to any one of claims 1-2, characterized in that, The mixing unit satisfies at least one of the following conditions: The flow-carrying gas inlet includes multiple arrayed gas distribution holes; The aerosol inlet and the mixture outlet are connected by a hollow pipe, and the ratio of the length of the hollow pipe to the diameter of the hollow pipe is greater than or equal to 4:

1.

4. The method according to any one of claims 1-2, characterized in that, The disinfection unit satisfies at least one of the following conditions: The angle between the gas flow direction and the disinfection electrode group is a right angle; An insulating mesh is provided between adjacent porous metal meshes; The vertical distance between adjacent porous metal meshes is 1 mm to 2 mm; The number of disinfection electrode groups in the disinfection unit is 4 to 12; The voltage between the positive and negative terminals of the external power supply is 5V~50V.

5. The method according to claim 4, characterized in that, The insulating mesh includes at least one of plastic mesh and nylon mesh; The porous metal mesh includes a porous copper mesh.

6. The method according to claim 1, characterized in that, The flow rate ratio of the aerosol to the carrier gas is (2-12):3.

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