System and method for enhancing sterilization and disinfection effect of plasma activated water

Abstract

In the system, an underwater double-bubble plasma generating device is electrically connected with a low-temperature plasma power supply, a pair of bubble reactors are arranged at intervals and at least partially immersed in a container, and a metal rod extends in a quartz tube through a positioning ring connected with a tube opening of the quartz tube; the metal rod is connected with a low-temperature plasma power supply; the gas channel introduces gas into the quartz tube through the positioning ring; the nitrogen source is communicated with one bubble reactor to introduce nitrogen through an air passage, the argon source is communicated with the other bubble reactor to introduce argon through an air passage, and when voltage is applied to the two metal bars of the pair of bubble reactors, the two bubble reactors discharge simultaneously to generate plasmas so as to generate NO2-and H2O2 active particles respectively; nO2 <-> and H2O2 active particles react to generate ONOO <->, and the sterilization and disinfection functions of the plasma activated water are enhanced based on a chemical path of the system.

Description

Technical Field

[0001] The invention relates to the field of plasma chemistry and biomedical technology, in particular to an enhanced plasma activated water sterilization and disinfection system and method. Background Art

[0002] In the environment where humans live, there are various viruses and harmful bacteria, which seriously endanger human health and public health safety. Therefore, people have a strong demand for highly efficient disinfection and sterilization technology that can be widely used. At the same time, as people's awareness of environmental protection is awakened and the concept of sustainable development is deeply rooted in people's hearts, energy saving, environmental friendliness, sustainability and greenness have also become the development direction of new sterilization technologies.

[0003] Compared with traditional sterilization methods, low-temperature plasma activated water, that is, the use of low-temperature plasma to treat aqueous solutions, contains a variety of active particles such as hydrogen peroxide, nitric acid, hydroxyl radicals, oxygen free radicals, peroxynitrite (ONOOH), etc., which has a good killing effect on bacteria, viruses and other microorganisms, and has a large area of ​​action and mild effect. It can be used in public environment sterilization and disinfection, food sterilization and disinfection, and biomedicine. At the same time, the production method of activated water based on water and harmless gases such as nitrogen and air is environmentally friendly and less harmful to human health.

[0004] At present, there are many studies on the preparation methods of activated water. Usually, the air is discharged to form plasma, and then the plasma is introduced into the aqueous solution to form activated water. Most of the methods have poor controllability. Since there are many types of active substances with bactericidal effects and many conditions that affect the active substances, there are deficiencies in the control and optimization of the bactericidal effects. At the same time, the mode of action is relatively simple, the gas-liquid mass transfer efficiency is low, and the active substances cannot be fully utilized.

[0005] Studies have shown that peroxynitrite (ONOO - ) plays an important role in the sterilization process, but there is currently no relevant technical method to effectively control its concentration and thus control and enhance the actual sterilization effect of activated water.

[0006] The information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known to a person of ordinary skill in the art. Summary of the invention

[0007] In view of the shortcomings or defects of the prior art, an enhanced plasma activated water sterilization and disinfection system and method are provided, which utilizes an underwater bubble plasma generator and uses N2 and Ar as working gases to treat aqueous solution. Based on the principle, NO2 is effectively generated respectively. -and H2O2, ONOO can be further realized by using different gas ratios, different discharge temperatures, and different discharge times. - Controllable synthesis, and then control and improve the actual bactericidal effect.

[0008] The purpose of the present invention is achieved through the following technical solutions.

[0009] An enhanced plasma activated water sterilization and disinfection system comprises:

[0010] Low temperature plasma power supply;

[0011] An underwater double-bubble plasma generating device is electrically connected to the low-temperature plasma power supply, and the underwater double-bubble plasma generating device comprises:

[0012] a container containing an aqueous solution,

[0013] a pair of bubble reactors spaced apart and at least partially submerged in the container, the bubble reactors comprising,

[0014] A quartz tube with micro-holes at the bottom.

[0015] a metal rod extending in the quartz tube via a positioning ring connected to the tube mouth of the quartz tube, wherein the metal rod is connected to the low-temperature plasma power supply,

[0016] an air passage, which introduces gas into the quartz tube via the positioning ring;

[0017] a nitrogen source connected to a bubble reactor to introduce nitrogen through a gas passage,

[0018] An argon source is connected to another bubble reactor to introduce argon through the gas channel. When a voltage is applied to the two metal rods of a pair of bubble reactors, the two bubble reactors discharge simultaneously to generate plasma to generate NO2 - and H2O2 active particles, NO2 - React with H2O2 active particles to produce ONOO - .

[0019] The enhanced plasma activated water sterilization and disinfection system also includes a water cooling device for cooling the temperature of the aqueous solution.

[0020] In the enhanced plasma activated water sterilization and disinfection system, the container is a double-layer structure, and a water cooling device drives the circulating cooling water in the interlayer to circulate and cool the container.

[0021] In the enhanced plasma activated water sterilization and disinfection system, the inner diameter of the quartz tube is 6 mm, the outer diameter is 8 mm, the length is 150 mm, and the bottom has 8 evenly distributed micropores, each of which has a diameter of 200 μm.

[0022] In the enhanced plasma activated water sterilization and disinfection system, the low-temperature plasma power supply includes an AC power supply with periodic oscillation attenuation.

[0023] In the enhanced plasma activated water sterilization and disinfection system, the airway comprises a thin tube with a diameter of 1 mm that passes into a quartz tube.

[0024] The enhanced plasma activated water sterilization and disinfection system also includes detecting ONOO in the liquid product of the container. - The electron spin resonance spectroscopy unit of the active particle uses the 4-oxygen derivative of 2,2,6,6-tetramethylpiperidin-1-oxyl radical to detect ONOO in the liquid phase product. - Active particles.

[0025] In the enhanced plasma activated water sterilization and disinfection system, the aqueous solution is a deionized aqueous solution.

[0026] The treatment method of the enhanced plasma activated water sterilization and disinfection system comprises the following steps:

[0027] An underwater double-bubble plasma generating device is electrically connected to the low-temperature plasma power supply, and a pair of bubble reactors of the underwater double-bubble plasma generating device are arranged at intervals and at least partially immersed in the container;

[0028] A nitrogen source is connected to one bubble reactor to introduce nitrogen through a gas passage, and an argon source is connected to another bubble reactor to introduce argon through a gas passage;

[0029] A voltage is applied to the two metal rods of a pair of bubble reactors, and the two bubble reactors discharge simultaneously to generate plasma to generate NO2 - and H2O2 active particles, NO2 - React with H2O2 active particles to produce ONOO - , wherein the power-on time, the gas flow rate ratio of nitrogen flow rate to argon flow rate are controlled to adjust NO2 - The concentration of H2O2 and the temperature of the aqueous solution are adjusted by a water cooling device to adjust the generated ONOO - Active particles.

[0030] In the method, the flow rate of nitrogen and argon is 1:3, and the temperature of the aqueous solution is 60°C.

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] The present invention is a bubble reactor into which N2 is passed to discharge to generate NO2 - , a bubble reactor is introduced with Ar to produce H2O2, and then NO2 -Reacts with H2O2 to produce ONOO - , effectively disinfect bacteria and microorganisms. At the same time, by adjusting the ratio of gases, that is, adjusting NO2 - The concentration of H2O2 can effectively control the intensity of sterilization and improve the sterilization effect. The method is easy to expand and the parameters are controllable. The prepared activated water has the advantages of being environmentally friendly, green and harmless, controllable and efficient, and easy to prepare.

[0033] The above description is only an overview of the technical solution of the present invention. In order to make the technical means of the present invention clearer and to achieve the extent that those skilled in the art can implement it according to the contents of the specification, and in order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are exemplified below. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] By reading the detailed description of the preferred specific embodiments below, various other advantages and benefits of the present invention will become clear to those of ordinary skill in the art. The drawings in the specification are only for the purpose of illustrating the preferred embodiments and are not considered to be limitations of the present invention. Obviously, the drawings described below are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can also be obtained based on these drawings without creative work. Moreover, the same reference numerals are used to represent the same components throughout the drawings.

[0035] In the attached picture:

[0036] Figure 1 It is a schematic structural diagram of an enhanced plasma activated water sterilization and disinfection system provided by an embodiment of the present invention;

[0037] Figure 2 It is a synthetic ONOO provided by one embodiment of the present invention. - Schematic diagram of the path;

[0038] Figure 3 is a schematic structural diagram of a bubble reactor provided by an embodiment of the present invention;

[0039] Figure 4 ONOO provided by one embodiment of the present invention - Schematic diagram of the concentration variation curve over time under different gas ratio conditions;

[0040] Figure 5 ONOO provided by one embodiment of the present invention - Schematic diagram of the concentration variation curve over time under different temperature conditions;

[0041] Figure 6It is a schematic diagram of the sterilization effect of different gas conditions on aqueous solution bacteria provided by an example of the present invention.

[0042] The present invention is further explained below in conjunction with the accompanying drawings and embodiments. DETAILED DESCRIPTION

[0043] The specific embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although the specific embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present invention and to enable the scope of the present invention to be fully communicated to those skilled in the art.

[0044] It should be noted that certain words are used in the specification and claims to refer to specific components. Those skilled in the art should understand that technicians may use different nouns to refer to the same component. This specification and claims do not use the difference in nouns as a way to distinguish components, but use the difference in the functions of the components as the criterion for distinction. As mentioned throughout the specification and claims, "including" or "comprising" is an open term, so it should be interpreted as "including but not limited to". The subsequent description of the specification is a preferred embodiment of the present invention, but the description is based on the general principles of the specification and is not intended to limit the scope of the present invention. The scope of protection of the present invention shall be determined by the attached claims.

[0045] To facilitate understanding of the embodiments of the present invention, several specific embodiments will be further explained below with reference to the accompanying drawings, and each of the accompanying drawings does not constitute a limitation on the embodiments of the present invention.

[0046] For a better understanding, Figures 1 to 6 As shown, an enhanced plasma activated water sterilization and disinfection system comprises:

[0047] Low temperature plasma power supply;

[0048] An underwater double-bubble plasma generating device is electrically connected to the low-temperature plasma power supply, and the underwater double-bubble plasma generating device comprises:

[0049] a container containing an aqueous solution,

[0050] a pair of bubble reactors spaced apart and at least partially submerged in the container, the bubble reactors comprising,

[0051] A quartz tube with micro-holes at the bottom.

[0052] a metal rod extending in the quartz tube via a positioning ring connected to the tube mouth of the quartz tube, wherein the metal rod is connected to the low-temperature plasma power supply,

[0053] an air passage, which introduces gas into the quartz tube via the positioning ring;

[0054] a nitrogen source connected to a bubble reactor to introduce nitrogen through a gas passage,

[0055] An argon source is connected to another bubble reactor to introduce argon through the gas channel. When a voltage is applied to the two metal rods of a pair of bubble reactors, the two bubble reactors discharge simultaneously to generate plasma to generate NO2 - and H2O2 active particles, NO2 - React with H2O2 active particles to produce ONOO - .

[0056] In a preferred embodiment of the enhanced plasma activated water sterilization and disinfection system, a water cooling device for cooling the temperature of the aqueous solution is also included.

[0057] In a preferred embodiment of the enhanced plasma activated water sterilization and disinfection system, the container is a double-layer structure, and a water cooling device drives the circulating cooling water in the interlayer to circulate and cool the container.

[0058] In a preferred embodiment of the enhanced plasma activated water sterilization and disinfection system, the inner diameter of the quartz tube is 6 mm, the outer diameter is 8 mm, the length is 150 mm, and the bottom has 8 evenly distributed micropores, each of which has a diameter of 200 μm.

[0059] In a preferred embodiment of the enhanced plasma activated water sterilization and disinfection system, the low temperature plasma power supply comprises an AC power supply with periodic oscillation attenuation.

[0060] In a preferred embodiment of the enhanced plasma activated water sterilization and disinfection system, the airway comprises a thin tube with a diameter of 1 mm that passes into a quartz tube.

[0061] In a preferred embodiment of the enhanced plasma activated water sterilization and disinfection system, the system further comprises detecting ONOO in the liquid product of the container. - The electron spin resonance spectroscopy unit of the active particle uses the 4-oxygen derivative of 2,2,6,6-tetramethylpiperidin-1-oxyl radical to detect ONOO in the liquid phase product. - Active particles.

[0062] In a preferred embodiment of the enhanced plasma activated water sterilization and disinfection system, the aqueous solution is a deionized aqueous solution.

[0063] The treatment method of the enhanced plasma activated water sterilization and disinfection system comprises the following steps:

[0064] An underwater double-bubble plasma generating device is electrically connected to the low-temperature plasma power supply, and a pair of bubble reactors of the underwater double-bubble plasma generating device are arranged at intervals and at least partially immersed in the container;

[0065] A nitrogen source is connected to one bubble reactor to introduce nitrogen through a gas passage, and an argon source is connected to another bubble reactor to introduce argon through a gas passage;

[0066] A voltage is applied to the two metal rods of a pair of bubble reactors, and the two bubble reactors discharge simultaneously to generate plasma to generate NO2 - and H2O2 active particles, NO2 - React with H2O2 active particles to produce ONOO - , wherein the power-on time, the gas flow rate ratio of nitrogen flow rate to argon flow rate are controlled to adjust NO2 - The concentration of H2O2 and the temperature of the aqueous solution are adjusted by a water cooling device to adjust the generated ONOO - Active particles.

[0067] In a preferred embodiment of the method, the nitrogen flow rate and the argon flow rate are 1:3, and the temperature of the aqueous solution is 60°C.

[0068] This method uses N2 and Ar as working gases, which can effectively produce nitrite (NO2 - ) and hydrogen peroxide (H2O2), and peroxynitrite (ONOO - ) was synthesized by plasma activation of ONOO in water. - In addition, further activated water sterilization experiments further verified the ONOO - As a key bactericidal substance, it has the best effect when N2 / Ar=1:3, and can kill more than 5 orders of magnitude of Staphylococcus aureus. This method effectively improves the plasma activation of ONOO in water. - The production efficiency is improved, which enhances the bactericidal effect of activated water.

[0069] In one embodiment, the bubble reactor is composed of a quartz tube with an inner diameter of 6 mm, an outer diameter of 8 mm, a length of 150 mm, 8 evenly distributed micropores at the bottom, each micropore having a diameter of 200 μm and a stainless steel rod with an inner diameter of 4 mm in the quartz tube through a connecting device. The position of the stainless steel rod is fixed by a positioning ring to ensure that it is in the center of the quartz tube. Gas from the side of the device is passed into the quartz tube through a capillary tube with a diameter of 1 mm, and flows out evenly from the 8 micropores at the bottom through the edge notch of the positioning ring. When the bottom of the bubble reactor is placed underwater and gas is passed into the capillary tube, bubbles will be generated at the 8 micropores at the bottom of the reactor.

[0070] The two ends of a high-voltage power supply are respectively connected to two bubble reactors, the distance between the bubble reactors is more than 3 cm, the micropores at the bottom of the two bubble reactors, i.e., the gas outlets, are in the same container, the container contains an aqueous solution, and the gas outlets are all below the liquid surface of the solution, more than 2 cm away from the liquid surface. When voltage is applied to two stainless steel rods, i.e., electrodes, the two bubble reactors simultaneously discharge at the micropores to generate plasma. The plasma appears at the bottom of the quartz tube, in the area formed by the stainless steel rods, micropores, bubbles, and aqueous solution, and exists at 8 micropores at the same time.

[0071] One bubble reactor is fed with nitrogen, and the other bubble reactor is fed with argon. The inlet gas flow rate is controlled by different mass flow meters. The two bubble reactors discharge simultaneously to produce NO2 - and active particles such as H2O2, NO2 - Further reaction with H2O2 produces ONOO which plays an important role in the sterilization process. - , ONOO can be synthesized in a controllable manner by changing the gas ratio - Active particles to achieve better sterilization effect.

[0072] In one embodiment, the power source is an oscillating attenuated AC power source, which can more effectively promote the bursting of bubbles, generate smaller bubbles, and improve the efficiency of plasma chemical reactions.

[0073] The aqueous solution was treated with nitrogen and argon plasma to generate plasma activated water, and the flow rate of nitrogen and argon was in the range of 0~1 L / min. The discharge time was in the range of 0~10min.

[0074] In one embodiment, when the ratio of nitrogen to argon is 1:3, the most active particles are produced, the sterilization effect is optimal, and more than 5 orders of magnitude of Staphylococcus aureus can be killed.

[0075] In one embodiment, the high-voltage electrode and the ground electrode of the device are the internal stainless steel rods of the two bubble reactors, respectively. The double bubble reactors are separated by more than 3 cm to avoid direct discharge between the reactors. The micropores at the bottom of the reactor are placed underwater, more than 2 cm away from the water surface. Nitrogen is introduced into the bubble reactor at the high-voltage electrode, and argon is introduced into the bubble reactor at the ground electrode. The total flow rate of the two gases is 1 L / min. The flow rate is controlled by different gas mass flow controllers. The gas flow rate ratios used are as follows: nitrogen flow rate: argon flow rate = 0:4, 1:3, 2:2, 3:1 and 4:0. Five different gas flow rate ratios are used. By detecting the concentration of active particles under the above different gas flow rate ratios, the effective synthesis of ONOO- is controlled to further enhance the bactericidal effect on Staphylococcus aureus. After applying voltage to the two stainless steel electrodes, discharge occurs between the stainless steel and the aqueous solution. The plasma exists in the micropores at the bottom of the quartz tube and on the underwater bubbles. Through bubble discharge, the two single bubble reactors generate NO2 respectively. - and H2O2, and then the two react to form ONOO - This short-lived active particle is effective in killing bacteria.

[0076] The temperature of the aqueous solution is controlled by a water cooling device. The aqueous solution to be discharged is placed in a 150mL double-layer beaker, and the aqueous solution content is 150mL. The circulating cooling water circulates between the double-layer beaker and the water cooling device to control the temperature of the aqueous solution during discharge. After discharge, the ONOO in the liquid phase product is detected by electron spin resonance spectroscopy (ESR) using Tempone-H (4-oxygen derivative of 2,2,6,6-tetramethylpiperidin-1-oxyl free radical). - Active particles.

[0077] In one embodiment, 1. Activated water preparation experiment

[0078] First, the air inlet system, i.e., the gas mass flowmeter, is controlled to introduce 250 mL / min of N2 into a single bubble reactor, and 750 mL / min of argon into another single bubble reactor. The stainless steel rod in the reactor passing N2 is used as a high-voltage electrode, and the stainless steel rod in the reactor passing Ar is used as a ground electrode. An oscillating and attenuated AC power supply is applied between the two electrodes. Bubbles and plasma exist at the bottom micropores of the bubble reactors passing N2 and Ar. Under the action of plasma and bubbles, the gas and aqueous solution generate NO2 at the micropores of the two bubble reactors respectively. - and H2O2, which then react in solution to produce ONOO, an effective bactericidal - Active particles. This device can directly disinfect harmful bacteria in aqueous solutions, or use the prepared activated water to disinfect harmful bacteria indirectly.

[0079] 2. Experiment on regulating different gas ratios

[0080] Ensure that the total gas flow rate of N2 and Ar is 1L / min, control the gas flow rate ratio N2:Ar=0:4, 1:3, 2:2, 3:1, 4:0, and do 5 groups of discharge experiments under different gas ratios. Take a sample every 2 minutes, take 5 samples in each group, and the discharge time of a group is 10 minutes. The samples taken are tested by ESR for ONOO - Quantification of active particles. Use 10 minutes of samples per group for sterilization experiments. The experiment shows that under the conditions of N2 at 250mL / min and Ar at 750mL / min, ONOO - It has the highest concentration and the best bactericidal effect, and can kill more than 5 orders of magnitude of Staphylococcus aureus.

[0081] 3. Experiment on different discharge temperature control

[0082] The gas flow rate was set to 250 mL / min for N2 and 750 mL / min for Ar. The temperature of the discharge area was controlled by inputting circulating cooling water into the outer layer of the double-layer beaker of the reactor through a water cooling device. By setting the temperature gradient, 5 groups of discharge experiments were performed at different temperatures and 5 groups of samples were collected. The samples were subjected to ONOO - Quantification of active particles. Bactericidal experiments were performed using samples from each group for 10 minutes.

[0083] 4. Sterilization experiment

[0084] Staphylococcus aureus is a representative of Gram-positive bacteria and a common food-borne pathogenic microorganism. It often parasitizes on the skin, nasal cavity, throat, stomach, carbuncle, suppurative sores of humans and animals, and is also ubiquitous in air, sewage and other environments. International sterilization experiments often use this species as a typical object.

[0085] In this experiment, 1.5 mL of bacterial solution with OD1 concentration was taken and added into 150 mL of deionized water. Direct plasma discharge method was used for sterilization. 1 mL of the solution after discharge was taken and diluted successively to 1 / 10 of the original concentration in 5 gradients, and the bacterial solution was cultured in culture medium.

[0086] The basic principles of the present application are described above in conjunction with specific embodiments. However, it should be noted that the advantages, strengths, effects, etc. mentioned in the present application are only examples and not limitations, and it cannot be considered that these advantages, strengths, effects, etc. are required by each embodiment of the present application. In addition, the specific details disclosed above are only for the purpose of illustration and ease of understanding, not for limitation, and the above details do not limit the present application to being implemented by adopting the above specific details.

[0087] The above description has been given for the purpose of illustration and description. In addition, this description is not intended to limit the embodiments of the present application to the forms disclosed herein. Although multiple example aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, changes, additions and sub-combinations thereof.

Claims

1. An enhanced plasma activated water sterilization and disinfection system, characterized in that: These include, Low temperature plasma power supply; An underwater double-bubble plasma generating device is electrically connected to the low-temperature plasma power supply, and the underwater double-bubble plasma generating device comprises: a container containing an aqueous solution, a pair of bubble reactors spaced apart and at least partially submerged in the container, the bubble reactors comprising, A quartz tube with micro-holes at the bottom. a metal rod extending in the quartz tube via a positioning ring connected to the tube mouth of the quartz tube, wherein the metal rod is connected to the low-temperature plasma power supply, an air passage, which introduces gas into the quartz tube via the positioning ring; a nitrogen source connected to a bubble reactor to introduce nitrogen through a gas passage, An argon source is connected to another bubble reactor to introduce argon through the gas channel. When a voltage is applied to the two metal rods of a pair of bubble reactors, the two bubble reactors discharge simultaneously to generate plasma to generate NO2 - and H2O2 active particles, NO2 - React with H2O2 active particles to produce ONOO - .

2. The enhanced plasma activated water sterilization and disinfection system as claimed in claim 1, characterized in that: Preferably, it also includes a water cooling device for cooling the temperature of the aqueous solution.

3. The enhanced plasma activated water sterilization and disinfection system as claimed in claim 2, characterized in that: The container is a double-layer structure, and the water cooling device drives the circulating cooling water in the interlayer to circulate and cool the container.

4. The enhanced plasma activated water sterilization and disinfection system as claimed in claim 1, characterized in that: The inner diameter of the quartz tube is 6 mm, the outer diameter is 8 mm, the length is 150 mm, and the bottom has 8 evenly distributed micropores, each with a diameter of 200 μm.

5. The enhanced plasma activated water sterilization and disinfection system as claimed in claim 1, characterized in that: The low temperature plasma power source comprises an alternating current power source with periodic oscillation decay.

6. The enhanced plasma activated water sterilization and disinfection system as claimed in claim 1, characterized in that: The airway consisted of a thin tube with a diameter of 1 mm leading into a quartz tube.

7. The enhanced plasma activated water sterilization and disinfection system as claimed in claim 1, characterized in that: It also includes detecting ONOO in the liquid product of the container. - The electron spin resonance spectroscopy unit of the active particle uses the 4-oxygen derivative of 2,2,6,6-tetramethylpiperidin-1-oxyl radical to detect ONOO in the liquid phase product. - Active particles.

8. The enhanced plasma activated water sterilization and disinfection system as claimed in claim 1, characterized in that: The aqueous solution is a deionized aqueous solution.

9. The treatment method of the enhanced plasma activated water sterilization and disinfection system according to any one of claims 1 to 8.

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