Bacterial inactivation method based on micro-nano bubble ozone synergistic reaction

Abstract

The present application relates to the technical field of water body bacteria inactivation, and particularly relates to a bacteria inactivation method based on micro-nano bubble ozone synergistic reaction, comprising the following steps: mixing and conveying ozone gas dissolved water and initial sewage to a front reactor to output as dissolved air sewage; conveying the dissolved air sewage to a reaction tank; obtaining the pressure of a plurality of pressure sampling positions of a conveying pipeline conveying the dissolved air sewage; determining the merging state of micro-nano bubbles in the conveying pipeline; determining an abnormal area in the merging state of the micro-nano bubbles; determining the bubble merging amount of the abnormal area based on the obtained conveying pipeline pressure of the position where the connecting port is located and the average pressure in the conveying pipeline behind the connecting port; determining the dosing amount of alkaline substances and the replenishment amount of the dissolved air water; and continuously conveying the dissolved air sewage from the front reactor to the reaction tank to complete the bacteria inactivation operation, so that the cavitation effect of ozone micro-nano bubbles is strengthened and the solubility of ozone in water is improved.

Description

Technical Field

[0001] This invention relates to the field of aquatic bacteria inactivation technology, and in particular to a bacterial inactivation method based on the synergistic reaction of micro-nano bubble ozone. Background Technology

[0002] In the field of water treatment, bacterial inactivation is a crucial step in ensuring water quality safety. Ozone, due to its strong oxidizing properties and lack of secondary pollution, is widely used for bacterial inactivation treatment of drinking water and sewage. However, traditional ozone treatment technologies suffer from low ozone gas solubility in water, poor mass transfer efficiency, and the fact that most ozone escapes without participating in the reaction, leading to low utilization and high treatment costs. The rise of micro-nano bubble technology offers a new approach to solving this problem. Micro-nano bubbles, with their large specific surface area, long residence time in water, and high mass transfer efficiency, can significantly improve the solubility and dispersion of ozone in water, greatly enhancing inactivation efficiency. However, existing ozone-assisted inactivation technologies based on micro- and nanobubbles still face challenges. Micro- and nanobubbles are prone to Brownian motion in water, leading to a sharp decrease in specific surface area and reduced mass transfer capacity, which directly weakens the efficiency of ozone interaction with bacteria. Furthermore, small particulate matter in the water can easily adsorb onto the surface of micro- and nanobubbles, blocking the gas-liquid interface and hindering the release of ozone from the bubbles into the water. At the same time, particles may encapsulate bacteria, reducing the inactivation effect. Therefore, there is an urgent need for a micro- and nanobubble-assisted ozone-bacterial inactivation method that inhibits the aggregation of micro- and nanobubbles, reduces the interference of small particulate matter on the gas-liquid interface, and maintains efficient system operation through dynamic regulation.

[0003] Chinese Patent Publication No. CN118598336B discloses a method for disinfecting drinking water with nano-ion ozone, comprising: preparing pure water from municipal water and storing the pure water in a water tank; taking the pure water and pumping in first micro-nano ozone bubbles under pressure to prepare mixed water; adding the mixed water to the water tank and mixing it with the pure water, while simultaneously pumping in second micro-nano ozone bubbles under pressure to complete the disinfection of the drinking water. Compared with the method of directly purifying with micro-nano ozone bubbles, this invention can increase the content of micro-nano ozone bubbles in the pure water, significantly improving the purification effect. The pore size of micro-nano ozone bubbles determines the content of micro-nano ozone bubbles in the mixed water and the production rate of the mixed water. Furthermore, the mixed water cannot be stored for extended periods, requiring real-time adjustment of the micro-nano ozone bubble pore size in conjunction with the consumption rate of drinking water to achieve optimal purification while minimizing ozone emissions. Therefore, the nano-ion ozone disinfection method for drinking water suffers from a problem: prolonged use of the wastewater transport pipeline leads to the deposition and adhesion of oil droplets and other particulate matter on the pipeline walls, resulting in increased pressure in the pipeline and a stronger impact of the wastewater on the dissolved air water, thus increasing the collision probability of micro-nano bubbles in the dissolved air water. Summary of the Invention

[0004] To address this issue, the present invention provides a bacterial inactivation method based on the synergistic reaction of micro-nano bubbles and ozone, which overcomes the problem in the prior art where, due to prolonged use of sewage transport pipelines, particulate matter such as oil droplets in the sewage deposits and adheres to the walls of the pipelines, leading to increased pressure in the transport pipelines and thus enhanced impact of sewage on dissolved air water, thereby increasing the collision probability of micro-nano bubbles in the dissolved air water.

[0005] To achieve the above objectives, the present invention provides a bacterial inactivation method based on the synergistic reaction of micro-nano bubble ozone, comprising: mixing dissolved ozone gas-containing water with initial wastewater extracted from a regulating tank and transporting it to a pre-reactor to output dissolved ozone-containing wastewater containing micro-nano bubbles;

[0006] The dissolved gas wastewater is transported to the reaction tank;

[0007] Obtain the pressure at several pressure sampling locations along the pipeline that transports the dissolved gas wastewater;

[0008] Determine the abnormal pressure state in the delivery pipeline based on the corresponding pressure sampling location that meets the preset pressure conditions;

[0009] The abnormal state region of the micro-nano bubble is determined based on the relative position of the corresponding pressure sampling location and the connection port between the output pipeline of the micro-nano bubble reactor and the delivery pipeline, and the average pressure in the delivery pipeline after the connection port.

[0010] Obtain the pressure of the delivery pipeline at the location of the connection port;

[0011] The amount of bubble merging in the abnormal area is determined based on the pressure in the delivery pipeline at the location of the connection port and the average pressure in the delivery pipeline downstream of the connection port.

[0012] Adjust the amount of alkaline substances added to the wastewater in the equalization tank according to the amount of bubbles merging in the abnormal area.

[0013] The temperature change of the pre-reactor within the monitoring time range that generates the average pressure is obtained.

[0014] The amount of dissolved air water to be replenished is determined based on the change in temperature.

[0015] The dissolved air wastewater continues to be transported from the pre-reactor to the reaction tank according to the replenishment amount of dissolved air water, so as to complete the bacterial inactivation operation;

[0016] The location where the alkaline substance is placed is determined based on the amount of bubbles merging in the abnormal area.

[0017] Furthermore, determining the merging state of micro / nano bubbles in the delivery pipeline based on the corresponding pressure sampling position that meets the preset pressure conditions includes:

[0018] The pressure at each pressure sampling location is compared with the preset pressure;

[0019] If the preset pressure condition is met, that is, the pressure at the sampling location is greater than the preset pressure, and the corresponding pressure sampling location meets the preset length condition, then it is determined that the pressure in the delivery pipeline is in an abnormal state.

[0020] The preset length condition is that the length of the corresponding pressure sampling position along the conveying direction of the conveying pipeline is greater than the preset length.

[0021] Furthermore, if the first cross-section of the conveying pipeline on the side of the pipeline space region corresponding to the pressure sampling position that meets the preset length condition is between the connection port and the inlet of the conveying pipeline, and the distance between the first cross-section of the conveying pipeline and the connection port is less than a preset distance, and the average pressure in the conveying pipeline after the connection port is less than a preset average pressure, then the pipeline space region between the first cross-section of the conveying pipeline and the inlet of the pre-reactor is determined as the abnormal state region of the micro-nano bubbles.

[0022] If the first cross section of the delivery pipeline is between the connection port and the inlet of the delivery pipeline, and the distance between the first cross section of the delivery pipeline and the connection port is less than a preset distance, and the average pressure in the delivery pipeline after the connection port is greater than or equal to the preset average pressure, then the delivery pipeline space area between the first cross section of the delivery pipeline and the second cross section of the delivery pipeline on the side away from the inlet of the delivery pipeline corresponding to the pipeline space area of ​​the corresponding pressure sampling position is determined as the abnormal state area of ​​micro-nano bubbles.

[0023] If the first cross-section of the delivery pipeline is between the connection port and the inlet of the pre-reactor, or the distance between the first cross-section of the delivery pipeline and the connection port is greater than one of the preset distances, then it is determined that there is no abnormal region of micro-nano bubbles in the delivery pipeline.

[0024] Furthermore, the average pressure is the ratio of the sum of the pressures at all pressure sampling points in the delivery pipeline after the connection port to the number of pressure sampling points in the delivery pipeline after the connection port.

[0025] Further, determining the amount of bubble merging in the abnormal area based on the pressure in the delivery pipeline at the location of the connection port and the average pressure in the delivery pipeline downstream of the connection port includes:

[0026] Compare the pressure in the delivery pipeline at the location of the connection port with the average pressure;

[0027] The product of the pressure difference between the delivery pipeline at the connection point and the average pressure and the bubble volume conversion coefficient is determined as the bubble merging amount in the abnormal area.

[0028] Furthermore, adjusting the amount of alkaline substances added to the wastewater in the equalization tank based on the amount of bubbles merging in the abnormal area includes:

[0029] Compare the amount of bubbles merged in the abnormal area with the preset merging amount;

[0030] If the amount of bubbles merging in the abnormal area is greater than the preset merging amount, the amount of alkaline substance added is reduced, and the placement of the alkaline substance is adjusted from above the regulating tank to between the connection port and the inlet of the pre-reactor.

[0031] Furthermore, the amount of alkaline substance added is negatively correlated with the amount of bubbles merging in the abnormal area.

[0032] Furthermore, the temperature change is the difference between the final temperature and the initial temperature of the pre-reactor within the monitoring time range, wherein,

[0033] The monitoring time range is from the start time of determining the abnormal state region of the micro-nano bubbles to the time when the calculation of the bubble merging amount in the abnormal region is completed.

[0034] Further, determining the replenishment amount of dissolved air water based on the temperature change includes:

[0035] The temperature change is compared with the preset temperature change.

[0036] If the temperature change is greater than the preset change, the amount of dissolved air water replenished will be increased according to the temperature increase.

[0037] Furthermore, the amount of dissolved air water replenished is positively correlated with the change in temperature.

[0038] Compared with existing technologies, the beneficial effects of this invention are as follows: This invention further monitors the merging state of micro-nano bubbles in the conveying pipeline by obtaining pressure at several pressure sampling locations along the pipeline for dissolved air wastewater. It then adjusts the dosage of alkaline substances accordingly, thereby regulating the pH value and ionic environment of the wastewater, maintaining the surface stability of the micro-nano bubbles, preventing them from merging due to interaction, thus reducing ineffective bubble merging, extending the residence time of micro-nano bubbles, improving the contact efficiency between ozone and bacteria in the wastewater, and enhancing the inactivation effect. The amount of bubble merging is determined based on the pressure in the conveying pipeline at the connection point and the average pressure in the conveying pipeline downstream of the connection point. This is achieved by utilizing the pressure change pattern caused by bubble merging, quantifying the correlation between the pressure difference and the degree of bubble merging to calculate the amount of bubble merging. When bubbles merge, the bubble size increases and the number decreases, thereby reducing the dispersion of bubbles in the fluid and increasing flow resistance. As the flow rate decreases, the pressure within the pipeline drops. The connection port is a crucial node for the micro-nano bubbles to enter the subsequent delivery pipeline leading to the reaction tank. The pressure at the connection port can be considered as the initial pressure when the bubbles enter the delivery pipeline after the connection port. The bubbles in the delivery pipeline after the connection port may merge as they flow, and the average pressure reflects the overall pressure state after the bubbles merge in this section of the pipeline. The ozone dissolution process in water is accompanied by a thermal effect. The initial oxidation reaction of ozone with pollutants in wastewater is an exothermic reaction. If the temperature change is positive, it indicates that the ozone dissolves sufficiently, and the generation and initial action of micro-nano bubbles are active. If the temperature change is negative, the ozone dissolution efficiency is low, and the activity of micro-nano bubbles is insufficient. By obtaining the temperature change of the pre-reactor within the time range of the average pressure generation, the intensity of ozone dissolution, micro-nano bubble formation, and initial reaction in the pre-reactor is reflected, further determining the amount of dissolved water containing ozone micro-nano bubbles to replenish.

[0039] Furthermore, this invention adjusts the amount of alkaline substance added to the wastewater in the equalization tank based on the amount of bubble merging in the abnormal area. If the abnormal area is on the pipeline from the outlet of the pre-reactor to the connection port, it indicates that the bubbles have already begun to destabilize in the initial mixing stage. Adjusting the amount of alkaline substance added in the equalization tank at this time optimizes the initial mixing environment of the wastewater and dissolved air water, preventing bubble merging in the early stages of formation. If the abnormal area is on the transport pipeline after the connection port to the reaction tank, it indicates that the bubbles have merged due to environmental changes during long-distance transport. Adjusting the amount of alkaline substance added in the equalization tank can specifically enhance the wastewater's ability to protect the bubbles, extending the stability period of the bubbles during transport. Additionally, the location of the alkaline substance added in this invention needs to be determined in conjunction with the distance between the area where the microplastics are located and the inlet. Due to their large specific surface area, microplastics easily adsorb micro- and nano-bubbles. If placed near areas with dense microplastics, a more stable alkaline microenvironment can be formed on the surface of the microplastics. The placement of alkaline substances is determined by the distance between the area where the microplastics are located and the inlet of the delivery pipeline. The anchoring effect of microplastics on bubbles reduces merging, and the local alkaline environment promotes the decomposition of ozone to generate active substances. By changing the acid-base environment of the equalization tank, ozone is easily decomposed rapidly through the hydroxyl radical pathway under alkaline conditions. By adjusting the amount of alkaline substances added, the rapid consumption of ozone due to an excessively alkaline environment can be avoided, extending its retention time in wastewater. At the same time, the encapsulation effect of micro- and nano-bubbles can slow down ozone dissipation. The combination of these two factors further improves the effective utilization rate of ozone.

[0040] Furthermore, this invention determines the amount of dissolved air water to be replenished based on the temperature change. When ozone reacts with bacteria and pollutants in wastewater, the reaction is predominantly exothermic, causing the temperature of the pre-reactor to rise. In this case, increasing the amount of dissolved air water replenished can provide fresh ozone, maintain the concentration and activity of micro-nano bubbles, and ensure the reaction remains efficient. If the temperature change is greater than a preset temperature change, it indicates that the dissolved air water is being consumed rapidly. In this case, increasing the amount of dissolved air water replenished can provide fresh ozone, maintaining the concentration and activity of micro-nano bubbles. When ozone is not fully dissolved, such as when the supply of dissolved air water is insufficient or there are few reactive substances in the wastewater, the exothermic reaction decreases, and because ozone dissipates, it carries away heat. If the temperature change is less than a preset temperature change, reducing the amount of dissolved air water replenished can prevent excessive ozone from dissipating due to not participating in the reaction, and also prevent excessive dilution of bubbles due to excessive dissolved air water. Attached Figure Description

[0041] Figure 1 This is an overall flowchart of the bacterial inactivation method based on the synergistic reaction of micro-nano bubble ozone in an embodiment of the present invention;

[0042] Figure 2 This is a flowchart illustrating the method for determining abnormal pressure in a delivery pipeline based on a bacterial inactivation method using micro-nano bubble ozone synergistic reaction, as described in an embodiment of the present invention.

[0043] Figure 3 This is a flowchart illustrating the method for adjusting the dosage of alkaline substances in a bacterial inactivation method based on the synergistic reaction of micro-nano bubble ozone according to an embodiment of the present invention.

[0044] Figure 4 This is a schematic diagram of the overall structure of the bacterial inactivation method based on the synergistic reaction of micro-nano bubble ozone in an embodiment of the present invention;

[0045] Explanation of reference numerals in the attached diagram: 1-Equalization tank, 2-Dissolved gas wastewater conveying pipeline, 3-Pressure sensor, 4-Pre-reactor, 5-Temperature sensor, 6-Reaction tank, 7-Ozone generator, 8-Micro-nano bubble generator, 9-Flow control valve, 10-Dissolved gas water replenishment pipeline. Detailed Implementation

[0046] To make the objectives and advantages of the present invention clearer, the present invention will be further described below with reference to embodiments; it should be understood that the specific embodiments described herein are merely for explaining the present invention and are not intended to limit the present invention.

[0047] Preferred embodiments of the present invention will now be described with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0048] It should be noted that in the description of this invention, the terms "upper", "lower", "left", "right", "inner", "outer", etc., which indicate directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings. This is only for the convenience of description and is not intended to indicate or imply that the device or element must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of this invention.

[0049] Furthermore, it should be noted that, in the description of this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0050] Please see Figure 1 , Figure 2 , Figure 3 as well as Figure 4The diagram shows the overall flow chart of the bacterial inactivation method based on the synergistic reaction of micro-nano bubble ozone, the method for determining the abnormal pressure of the delivery pipeline, the method for adjusting the amount of alkaline substance added, and the overall structural schematic diagram of the present invention. The bacterial inactivation method based on the synergistic reaction of micro-nano bubble ozone of the present invention includes: mixing dissolved water containing ozone gas and initial sewage extracted from the equalization tank 1 and transporting it to the pre-reactor 4 to output dissolved wastewater containing micro-nano bubbles.

[0051] The dissolved gas wastewater is transported to reaction tank 6;

[0052] Obtain the pressure at several pressure sampling locations in the conveying pipeline 2 that carries the dissolved gas wastewater;

[0053] Determine the abnormal pressure state in the delivery pipeline based on the corresponding pressure sampling location that meets the preset pressure conditions;

[0054] The abnormal state region of the micro-nano bubble is determined based on the relative position of the corresponding pressure sampling location and the connection port between the output pipeline of the micro-nano bubble reactor and the delivery pipeline, and the average pressure in the delivery pipeline after the connection port.

[0055] Obtain the pressure of the delivery pipeline at the location of the connection port;

[0056] The amount of bubble merging in the abnormal area is determined based on the pressure in the delivery pipeline at the location of the connection port and the average pressure in the delivery pipeline downstream of the connection port.

[0057] Adjust the amount of alkaline substances added to the wastewater in regulating tank 1 according to the amount of bubbles merging in the abnormal area.

[0058] The temperature change of the pre-reactor within the monitoring time range that generates the average pressure is obtained.

[0059] The amount of dissolved air water to be replenished is determined based on the change in temperature.

[0060] The dissolved air wastewater continues to be transported from the pre-reactor to the reaction tank 6 according to the replenishment amount of dissolved air water, so as to complete the bacterial inactivation operation;

[0061] The location where the alkaline substance is placed is determined based on the amount of bubbles merging in the abnormal area.

[0062] Specifically, the equalization tank 1 is made of reinforced concrete and has an effective volume of 50-200 cubic meters. Reactor 6 is a vertical cylindrical carbon steel tank with an effective volume of 10-50 cubic meters. The dissolved gas wastewater conveying pipeline 2 is made of 316 stainless steel with a diameter of DN80 to DN150. The length from the outlet to the connection port of the pre-reactor 4 is 4m, and the length from the connection port to the reaction tank 4 is 7m. The dissolved gas water replenishment pipeline 10 is made of UPVC with a diameter of DN25 to DN50. One end of the dissolved gas water replenishment pipeline 10 is connected to the outlet of the micro-nano bubble generator 8, and the other end is connected to the inlet section of the pre-reactor 4.

[0063] Specifically, the pre-reactor is a pressurized dissolved gas release reactor, which pressurizes and dissolves ozone in water in a closed container, and then depressurizes the solution through a release device, so that the supersaturated ozone is released into the initial wastewater in the form of micro-nano bubbles.

[0064] Specifically, the ozone generator 7 converts oxygen in the air into ozone with strong oxidizing properties through high-voltage discharge or electrolysis. The ozone generator 7 is a medium-frequency ozone generator. The micro-nano bubble generator 8 disperses the ozone gas output by the ozone generator 7 into the water to form micro-nano bubbles with a diameter of ~1000nm. The micro-nano bubble generator 8 combines the function of the pre-reactor and is selected as a pressurized dissolved gas micro-nano bubble generator. It also includes a dissolved gas tank, a release device and a circulation pump (not shown in the figure).

[0065] Specifically, high-precision pressure sensors 3 are installed at intervals of 0.2 meters on the conveying pipeline from the outlet of the pre-reactor to the connection port, and at intervals of 0.35 meters on the conveying pipeline from the connection port to the reaction tank 6.

[0066] Specifically, a temperature sensor 5 is installed at both the inlet and outlet of the pre-reactor 4.

[0067] Specifically, a pH sensor is installed at the inlet and outlet of the equalization tank 1, at the geometric center of the bottom of the equalization tank 1, and at the inlet of the pre-reactor 4. These sensors are used to monitor the pH uniformity after the addition of alkaline substances and to detect the pH value of the pretreated wastewater.

[0068] Specifically, a sensor based on a triboelectric nanogenerator is installed at the connection between the inlet pipe and the regulating tank 1 and at the inlet of the delivery pipe.

[0069] Specifically, the alkaline substance used to adjust the acid-base environment of the equalization tank 1 is sodium hydroxide, potassium hydroxide, or sodium carbonate.

[0070] Those skilled in the art will understand that the selection of the added alkaline substance needs to be adapted to the actual working conditions, such as the initial pH value of the wastewater, microplastics, and pollutant composition.

[0071] In implementation, this invention further monitors the merging state of micro- and nano-bubbles in the conveying pipeline 2 by obtaining pressure at several pressure sampling locations. It then adjusts the dosage of alkaline substances accordingly to regulate the pH value and ionic environment of the wastewater, maintain the surface stability of the micro- and nano-bubbles, prevent merging due to interactions, reduce ineffective bubble merging, prolong the residence time of micro- and nano-bubbles, improve the contact efficiency between ozone and bacteria in the wastewater, and enhance the inactivation effect. The amount of bubble merging is determined based on the pressure in the conveying pipeline at the connection point and the average pressure in the conveying pipeline downstream of the connection point. This is achieved by utilizing the pressure change pattern caused by bubble merging, quantifying the correlation between the pressure difference and the degree of bubble merging. When bubbles merge, the bubble size increases and the number decreases, thereby reducing the dispersion of bubbles in the fluid, decreasing flow resistance, and lowering the pressure within the pipeline. The pressure at the connection port is a key node for the micro-nano bubbles to enter the subsequent delivery pipeline leading to the reaction tank 6. The pressure at the connection port can be regarded as the initial pressure when the bubbles enter the delivery pipeline after the connection port. The bubbles in the delivery pipeline after the connection port may merge as they flow. The average pressure reflects the overall pressure state after the bubbles merge in this section of the pipeline. The ozone dissolution process in water is accompanied by a thermal effect. The initial oxidation reaction of ozone with pollutants in wastewater is an exothermic reaction. If the temperature change is positive, it indicates that the ozone dissolves sufficiently, and the generation and initial action of micro-nano bubbles are active. If the temperature change is negative, the ozone dissolution efficiency is low and the activity of micro-nano bubbles is insufficient. By obtaining the temperature change of the pre-reactor 4 within the time range of the average pressure generation, the intensity of ozone dissolution, micro-nano bubble formation and initial reaction in the pre-reactor 4 is reflected, and the amount of dissolved water containing ozone micro-nano bubbles is further determined.

[0072] Specifically, determining the merging state of micro / nano bubbles in the delivery pipeline based on the corresponding pressure sampling position that meets the preset pressure conditions includes:

[0073] The pressure at each pressure sampling location is compared with the preset pressure;

[0074] If the preset pressure condition is met, that is, the pressure at the sampling location is greater than the preset pressure, and the corresponding pressure sampling location meets the preset length condition, then it is determined that the pressure in the delivery pipeline is in an abnormal state.

[0075] The preset length condition is that the length of the corresponding pressure sampling position along the conveying direction of the conveying pipeline is greater than the preset length.

[0076] Optionally, the preset pressure range is [0.5MPa, 0.8MPa]; the preset length range is [0.6m, 1.75m].

[0077] Preferably, the preset pressure is 0.6 MPa in the preferred embodiment; and the preset length is 1.0 m in the preferred embodiment.

[0078] Specifically, when the pipeline flow rate is between 5 and 30... At / h, a preset pressure of 0.6MPa can distinguish between the stable pressure under normal dispersion of micro-nano bubbles and the local pressure increase caused by bubble merging.

[0079] Specifically, if the length of the corresponding pressure sampling position with a pressure greater than the preset pressure along the conveying direction of the conveying pipeline is less than or equal to the preset length, then the merging state of the micro-nano bubbles in the conveying pipeline is determined to be within the allowable range.

[0080] Specifically, if the first cross-section of the conveying pipeline on the side of the pipeline space region corresponding to the pressure sampling position that meets the preset length condition is between the connection port and the inlet of the conveying pipeline, and the distance between the first cross-section of the conveying pipeline and the connection port is less than a preset distance, and the average pressure in the conveying pipeline after the connection port is less than a preset average pressure, then the pipeline space region between the first cross-section of the conveying pipeline and the inlet of the pre-reactor 4 is determined as the abnormal state region of the micro-nano bubbles.

[0081] If the first cross section of the delivery pipeline is between the connection port and the inlet of the delivery pipeline, and the distance between the first cross section of the delivery pipeline and the connection port is less than a preset distance, and the average pressure in the delivery pipeline after the connection port is greater than or equal to the preset average pressure, then the delivery pipeline space area between the first cross section of the delivery pipeline and the second cross section of the delivery pipeline on the side away from the inlet of the delivery pipeline corresponding to the pipeline space area of ​​the corresponding pressure sampling position is determined as the abnormal state area of ​​micro-nano bubbles.

[0082] If the first cross-section of the delivery pipeline is between the connection port and the inlet of the pre-reactor 4, or the distance between the first cross-section of the delivery pipeline and the connection port is greater than one of the preset distances, then it is determined that there is no abnormal region of micro-nano bubbles in the delivery pipeline.

[0083] Optionally, the preset average pressure range is [0.2MPa, 0.4MPa]; the preset distance range is [0.4m, 0.8m].

[0084] Preferably, the preset average pressure is 0.3 MPa in the preferred embodiment; and the preset distance range is 0.5 m in the preferred embodiment.

[0085] Specifically, the average pressure is the ratio of the sum of the pressures at all pressure sampling points in the delivery pipeline after the connection to the number of pressure sampling points in the delivery pipeline after the connection.

[0086] Specifically, determining the amount of bubble merging in the abnormal area based on the pressure in the delivery pipeline at the location of the connection port and the average pressure in the delivery pipeline downstream of the connection port includes:

[0087] Compare the pressure in the delivery pipeline at the location of the connection port with the average pressure;

[0088] The product of the pressure difference between the delivery pipeline at the connection point and the average pressure and the bubble volume conversion coefficient is determined as the bubble merging amount in the abnormal area.

[0089] Specifically, the pressure bubble conversion coefficient was determined experimentally. The difference between the pressure of the delivery pipeline at each 0.1 MPa connection point and the average pressure corresponds to a 5% bubble merging rate, i.e., the bubble conversion coefficient is 0.05 / MPa.

[0090] Optionally, the preset merging amount ranges from [8%, 15%] of the total number of bubbles.

[0091] Preferably, the preset merging amount is 10% of the total number of bubbles.

[0092] Specifically, adjusting the amount of alkaline substances added to the wastewater in the equalization tank 1 based on the amount of bubbles merging in the abnormal area includes:

[0093] Compare the amount of bubbles merged in the abnormal area with the preset merging amount;

[0094] If the amount of bubbles merging in the abnormal area is greater than the preset merging amount, the amount of alkaline substance added is reduced, and the placement of the alkaline substance is adjusted from above the regulating tank 1 to between the connection port and the inlet of the pre-reactor 4.

[0095] In implementation, this invention adjusts the amount of alkaline substance added to the wastewater in the equalization tank 1 based on the amount of bubble merging in the abnormal area. If the abnormal area is on the pipeline from the outlet of the pre-reactor 4 to the connection port, it indicates that the bubbles have begun to destabilize in the initial mixing stage. Adjusting the amount of alkaline substance added to the equalization tank 1 at this time optimizes the initial mixing environment of the wastewater and dissolved air water, preventing bubble merging in the early stages of formation. If the abnormal area is on the transport pipeline after the connection port to the reaction tank 6, it indicates that the bubbles have merged due to environmental changes during long-distance transport. Adjusting the amount of alkaline substance added to the equalization tank 1 can specifically enhance the wastewater's protective ability against bubbles and extend the stability period of the bubbles during transport. Furthermore, the location of the alkaline substance added in this invention needs to be determined in conjunction with the distance between the area where the microplastics are located and the inlet. Due to their large specific surface area, microplastics easily adsorb micro- and nano-bubbles. If placed near areas with dense microplastics, a more stable alkaline microenvironment can be formed on the surface of the microplastics. The placement of alkaline substances is determined based on the distance between the area where the microplastics are located and the inlet of the delivery pipeline. The anchoring effect of microplastics on bubbles reduces merging, and the local alkaline environment promotes the decomposition of ozone to generate active substances. By changing the acid-base environment of equalization tank 1, ozone is easily decomposed rapidly through the hydroxyl radical pathway under alkaline conditions. By adjusting the amount of alkaline substances added, the rapid consumption of ozone due to an excessively alkaline environment can be avoided, extending its retention time in wastewater. At the same time, the encapsulation effect of micro- and nano-bubbles can slow down ozone dissipation. The combination of these two factors further improves the effective utilization rate of ozone.

[0096] Specifically, the amount of alkaline substance added is negatively correlated with the amount of bubbles merging in the abnormal area.

[0097] Specifically, the temperature change is the difference between the final temperature and the initial temperature of the pre-reactor 4 within the monitoring time range, wherein,

[0098] The monitoring time range is from the start time of determining the abnormal state region of the micro-nano bubbles to the time when the calculation of the bubble merging amount in the abnormal region is completed.

[0099] Specifically, determining the replenishment amount of dissolved air water based on the temperature change includes:

[0100] The temperature change is compared with the preset temperature change.

[0101] If the temperature change is greater than the preset change, the amount of dissolved air water replenished will be increased according to the temperature increase.

[0102] Specifically, dissolved air water is replenished through dissolved air water replenishment pipeline 10 and flow control valve 9. The PLC receives the temperature change signal of the pre-reactor 4 in real time and calculates the amount of dissolved air water to be replenished according to a preset algorithm. The PLC converts the amount of dissolved air water to be replenished into a corresponding current signal and sends it to the electric regulating valve. The electric regulating valve changes the opening degree of the valve core according to the signal.

[0103] The dissolved air water supply pipeline 10 and the flow control valve 9 have the same diameter; the flow control valve 9 is an electric regulating valve.

[0104] Optionally, the preset temperature change range is [1℃, 3℃].

[0105] Preferably, the preferred embodiment of the preset temperature change is 2°C.

[0106] In practice, when the temperature change exceeds 10% of the original value, the dissolved air water replenishment will be adjusted to 1.2 times the current replenishment amount. For every 5% exceeding 10%, the dissolved air water replenishment will be increased by 0.1 times.

[0107] If the deviation is less than or equal to 10%, the amount of dissolved air water to be replenished is multiplied by 1.2.

[0108] If the deviation is greater than 10%, the amount of dissolved air water to be replenished is calculated as follows: (1.2 + (deviation value / 5) × 0.1).

[0109] The deviation value is the change in temperature minus the preset temperature change.

[0110] For example, if the current temperature change is 2.2℃, the current dissolved air water replenishment is 5. / h, the increased dissolved air water replenishment amount is 5 / h×1.2=6 / h;

[0111] The current temperature change is 3°C, and the current dissolved air water replenishment is 5. / h, the increased dissolved air water replenishment amount is 5 / h×[1.2+(50% / 5%)×0.1]=5 / h×(1.2+10×0.1)=5 / h×2.2=11 / h.

[0112] In practice, this invention determines the amount of dissolved air water to be replenished based on the temperature change. When ozone reacts with bacteria and pollutants in wastewater, the reaction is predominantly exothermic, causing the temperature of the pre-reactor 4 to rise. In this case, increasing the amount of dissolved air water replenished can provide fresh ozone, maintain the concentration and activity of micro-nano bubbles, and ensure the reaction remains efficient. If the temperature change is greater than the preset temperature change, it indicates that the dissolved air water is being consumed rapidly. In this case, increasing the amount of dissolved air water replenished can provide fresh ozone, maintaining the concentration and activity of micro-nano bubbles. When ozone is not fully dissolved, such as due to insufficient dissolved air water supply or a lack of reactive substances in the wastewater, the exothermic reaction decreases, and because ozone dissipates, it carries away heat. If the temperature change is less than the preset temperature change, reducing the amount of dissolved air water replenished can prevent excessive ozone from dissipating due to not participating in the reaction, and also prevent excessive dilution of bubbles due to excessive dissolved air water.

[0113] Specifically, the amount of dissolved air water replenished is positively correlated with the change in temperature.

[0114] Working process: First, dissolved air containing ozone gas generated by ozone generator 7 and micro-nano bubble generator 8 is mixed with the initial sewage extracted from equalization tank 1 and transported together to pre-reactor 4. After treatment by pre-reactor 4, dissolved air sewage containing micro-nano bubbles is output. Subsequently, the dissolved air sewage is transported to reaction tank 6 for subsequent bacterial inactivation reaction. During the transportation of dissolved air sewage, pressure is monitored at several pressure sampling points of the dissolved air sewage transportation pipeline 2. By comparing the pressure at each sampling point with the preset pressure, if the length of the corresponding sampling point along the transportation direction meets the preset length condition when the pressure is greater than the preset pressure, it is determined that there is an abnormal pressure state in the dissolved air sewage transportation pipeline 2. This state is related to the merging state of micro-nano bubbles. Based on the corresponding sampling locations of the aforementioned pressure anomalies, combined with their relative positions to the connection ports of the micro / nano bubble reactor 8's output and delivery pipelines, and the average pressure of the delivery pipeline downstream of the connection port (i.e., the ratio of the sum of pressures at all pressure sampling locations downstream of the connection port to the number of samples), the abnormal state region of the micro / nano bubbles is determined. If the first cross-section of the pressure anomaly segment near the inlet is located between the connection port and the inlet of the delivery pipeline, and the distance between this cross-section and the connection port is less than a preset distance, and the average pressure downstream of the connection port is less than a preset average pressure, then the abnormal region is the pipeline space from the first cross-section to the inlet of the pre-reactor. If the above positional relationship remains unchanged but the average pressure downstream of the connection port is not less than the preset average pressure, then the abnormal region is the pipeline space from the first cross-section to the second cross-section of the pressure anomaly segment away from the inlet. If the first cross-section is located between the connection port and the inlet of the pre-reactor, or the distance from the connection port is greater than a preset distance, then it is determined that there is no abnormal region. After obtaining the delivery pipeline pressure at the connection port, the difference between this pressure and the average pressure downstream of the connection port is calculated, and then multiplied by the bubble quantity conversion coefficient to obtain the bubble merging amount in the abnormal region. The amount of alkaline substances added to the wastewater in the equalization tank is adjusted based on the amount of air bubbles merging. If the merging amount exceeds the preset amount, the amount added is reduced, and the placement location is adjusted from above the equalization tank to between the connection port and the inlet of the pre-reactor. The amount added is negatively correlated with the merging amount. Simultaneously, the temperature change in the pre-reactor is recorded from the initial moment of identifying the abnormal area to the completion of the air bubble merging calculation. This temperature change is compared with the preset temperature change; if the former is greater, the dissolved air water replenishment is increased accordingly. The replenishment amount is positively correlated with the temperature change.

[0115] According to the determined dissolved air water replenishment volume, the dissolved air wastewater continues to be transported from the pre-reactor to the reaction tank to finally complete the inactivation of bacteria in the wastewater.

[0116] The technical solution of the present invention has been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the scope of protection of the present invention.

Claims

1. A method for bacterial inactivation based on the synergistic reaction of micro / nanobubbles and ozone, characterized in that, include: Dissolved ozone gas-containing water is mixed with initial wastewater drawn from the equalization tank and transported to the pre-reactor to output dissolved ozone-containing wastewater with micro-nano bubbles. The dissolved gas wastewater is transported to the reaction tank; Obtain the pressure at several pressure sampling locations along the pipeline that transports the dissolved gas wastewater; Determine the abnormal pressure state in the delivery pipeline based on the corresponding pressure sampling location that meets the preset pressure conditions; The abnormal state region of the micro-nano bubble is determined based on the relative position of the corresponding pressure sampling location and the connection port between the output pipeline of the micro-nano bubble reactor and the delivery pipeline, and the average pressure in the delivery pipeline after the connection port. Obtain the pressure of the delivery pipeline at the location of the connection port; The amount of bubble merging in the abnormal area is determined based on the pressure in the delivery pipeline at the location of the connection port and the average pressure in the delivery pipeline downstream of the connection port. Adjust the amount of alkaline substances added to the wastewater in the equalization tank according to the amount of bubbles merging in the abnormal area. The temperature change of the pre-reactor within the monitoring time range that generates the average pressure is obtained. The amount of dissolved air water to be replenished is determined based on the change in temperature. The dissolved air wastewater continues to be transported from the pre-reactor to the reaction tank according to the replenishment amount of dissolved air water, so as to complete the bacterial inactivation operation; The location where the alkaline substance is placed is determined based on the amount of bubbles merging in the abnormal area.

2. The bacterial inactivation method based on the synergistic reaction of micro / nano bubble ozone according to claim 1, characterized in that, The step of determining the merging state of micro-nano bubbles in the delivery pipeline based on the corresponding pressure sampling position that meets the preset pressure conditions includes: The pressure at each pressure sampling location is compared with the preset pressure; If the preset pressure condition is met, that is, the pressure at the sampling location is greater than the preset pressure, and the corresponding pressure sampling location meets the preset length condition, then it is determined that the pressure in the delivery pipeline is in an abnormal state. The preset length condition is that the length of the corresponding pressure sampling position along the conveying direction of the conveying pipeline is greater than the preset length.

3. The bacterial inactivation method based on the synergistic reaction of micro / nano bubble ozone according to claim 2, characterized in that, If the first cross-section of the conveying pipeline on the side of the pipeline space region corresponding to the pressure sampling position that meets the preset length condition is between the connection port and the inlet of the conveying pipeline, and the distance between the first cross-section of the conveying pipeline and the connection port is less than a preset distance, and the average pressure in the conveying pipeline after the connection port is less than a preset average pressure, then the pipeline space region between the first cross-section of the conveying pipeline and the inlet of the pre-reactor is determined as the abnormal state region of the micro-nano bubbles. If the first cross section of the delivery pipeline is between the connection port and the inlet of the delivery pipeline, and the distance between the first cross section of the delivery pipeline and the connection port is less than a preset distance, and the average pressure in the delivery pipeline after the connection port is greater than or equal to the preset average pressure, then the delivery pipeline space area between the first cross section of the delivery pipeline and the second cross section of the delivery pipeline on the side away from the inlet of the delivery pipeline corresponding to the pipeline space area of ​​the corresponding pressure sampling position is determined as an abnormal state area of ​​micro-nano bubbles. If the first cross-section of the delivery pipeline is between the connection port and the inlet of the pre-reactor, or the distance between the first cross-section of the delivery pipeline and the connection port is greater than one of the preset distances, then it is determined that there is no abnormal region of micro-nano bubbles in the delivery pipeline.

4. The bacterial inactivation method based on the synergistic reaction of micro / nano bubble ozone according to claim 3, characterized in that, The average pressure is the ratio of the sum of the pressures at all pressure sampling points in the delivery pipeline after the connection to the number of pressure sampling points in the delivery pipeline after the connection.

5. The bacterial inactivation method based on the synergistic reaction of micro / nano bubble ozone according to claim 4, characterized in that, The determination of the bubble merging amount in the abnormal area based on the pressure in the delivery pipeline at the location of the connection port and the average pressure in the delivery pipeline downstream of the connection port includes: Compare the pressure in the delivery pipeline at the location of the connection port with the average pressure; The product of the pressure difference between the delivery pipeline at the connection point and the average pressure and the bubble volume conversion coefficient is determined as the bubble merging amount in the abnormal area.

6. The bacterial inactivation method based on the synergistic reaction of micro / nano bubble ozone according to claim 5, characterized in that, The temperature change is the difference between the final temperature and the initial temperature of the pre-reactor within the monitoring time range, wherein, The monitoring time range is from the start time of determining the abnormal state region of the micro-nano bubbles to the time when the calculation of the bubble merging amount in the abnormal region is completed.

7. The bacterial inactivation method based on the synergistic reaction of micro / nano bubble ozone according to claim 6, characterized in that, Determining the replenishment amount of dissolved air water based on the temperature change includes: The temperature change is compared with the preset temperature change. If the temperature change is greater than the preset change, the amount of dissolved air water replenished will be increased according to the temperature increase.

8. The bacterial inactivation method based on the synergistic reaction of micro / nano bubble ozone according to claim 7, characterized in that, The amount of dissolved air water replenished is positively correlated with the change in temperature.

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