Green bactericide for water treatment, preparation method and application

Abstract

The application discloses a kind of green bactericides for water treatment, preparation method and application, it is related to water treatment bactericides technical field, including by mass fraction, analytical pure sodium hypochlorite is more than 7%, penetrant 0.01%-0.03%, corrosion inhibitor 0.3%-0.5%, stabilizer 0.01%-0.02%;The application realizes multilevel sterilization mechanism by the synergistic effect of penetrant and sodium hypochlorite;Compound sodium carbonate as corrosion inhibitor, can form dense protective film on the surface of metal equipment, under the condition of guaranteeing can kill microorganism and multicellular organism propagule, can also slow down the corrosion of water pipeline and other equipment;Collaborate sodium silicate stabilizer to build buffer stable system, can form colloidal protective layer in the periphery of sodium hypochlorite active component, effectively inhibit effective chlorine decomposition loss, long drug efficacy retention period;Discard traditional card pine, benzalkonium chloride and other organic bactericidal components with safety hazard, reagent has no harmful residue, no pollution, water quality is clean and safe after processing.

Description

Technical Field

[0001] This invention relates to the field of water treatment bactericides, and in particular to a green bactericide for water treatment, its preparation method, and its application. Background Technology

[0002] In industrial production processes, cooling water systems, circulating water systems, and process water systems have strict requirements for water quality stability and microbial control. The effectiveness of water treatment directly affects equipment operating efficiency, energy consumption levels, and product quality. The salt industry primarily uses freshwater from natural reservoirs or rivers.

[0003] Freshwater from natural reservoirs contains a certain amount of microorganisms, multicellular organisms, and nutrients. In production enterprises, this freshwater is used as cooling water or sealing water for equipment. When the water flows through heat exchange equipment such as air coolers, filters, and pumps, the water temperature can rise to 50°C. Under suitable conditions of temperature, pH, and nutrients, microorganisms and multicellular organisms continuously multiply in the water of the production system, attaching to the surface of the equipment, reducing heat exchange efficiency, promoting corrosion of metal materials, shortening the service life of equipment, and even causing pipe blockage, leading to increased production energy consumption, higher maintenance costs, and in severe cases, affecting production safety.

[0004] As an important component of the water treatment field, bactericide technology aims to kill or inhibit the growth and reproduction of microorganisms such as bacteria, fungi, algae, and multicellular organisms in water bodies through chemical means, thereby preventing problems such as microbial corrosion, bioscale deposition, and water quality deterioration from adversely affecting industrial production.

[0005] Traditional water treatment disinfectants mainly use industrial sodium hypochlorite or add Kathon, benzalkonium chloride, etc. as the main components. Although using sodium hypochlorite as a single disinfectant has the advantages of high disinfection efficiency and low cost, it has the inherent defect of insufficient penetration ability. It cannot effectively penetrate the gelatinous protective film on the outside of aquatic organism egg masses, so its killing effect on large multicellular organisms such as snails is very limited, and it is difficult to curb the continuous reproduction of aquatic organisms in the system from the source. At the same time, the strong oxidizing property of sodium hypochlorite will cause varying degrees of corrosion to common metal equipment materials such as carbon steel, stainless steel, and copper, resulting in reduced heat exchange efficiency and shortened equipment life.

[0006] While organic bactericides such as Kathon and benzalkonium chloride have good inhibitory effects on some microorganisms, their chemical composition is difficult to meet the safety production requirements of food-related industries. Under high temperature conditions, they may decompose and release harmful substances or generate corrosive gases to equipment, which may seriously affect product quality and enterprise production safety.

[0007] For food production enterprises such as salt producers, one of the key technologies to be tackled is how to effectively control microorganisms and multicellular organisms in freshwater without causing equipment corrosion or introducing harmful residues, while ensuring that the treated water quality meets the requirements of national food safety standards. Summary of the Invention

[0008] To overcome the shortcomings of existing technologies, the purpose of this invention is to provide a green bactericide, its preparation method, and its application for water treatment, so as to achieve efficient, non-corrosive, green, and safe sterilization of water used in the food industry.

[0009] To address the problems of the prior art, the technical solution of the present invention is as follows: A green bactericide for water treatment, comprising the following components by mass fraction: >7% sodium hypochlorite (analytical grade), 0.01%-0.03% penetrant, 0.3%-0.5% corrosion inhibitor, 0.01%-0.02% stabilizer, with the balance being demineralized water; The penetrant is a mixture of Tween-80 and EDTA; the corrosion inhibitor is sodium carbonate. The stabilizer used is sodium silicate; the mass ratio of Tween-80 to EDTA is 1:1.

[0010] A method for preparing a green bactericide for water treatment includes the following steps: S1. Prepare single-component solutions of stabilizer sodium silicate, corrosion inhibitor sodium carbonate and penetrant using demineralized water. S2. Slowly add the prepared stabilizer solution to the analytical grade sodium hypochlorite solution while stirring. S3. Slowly add the prepared corrosion inhibitor solution to the mixed solution obtained in S2, and continue stirring; S4. Slowly add the prepared penetrant solution to the mixed solution obtained in S3, continue stirring, and let it stand after mixing to obtain the mixed solution; S5. Filter the mixture that has been left to stand in S4, and fill the filtrate into a light-proof, sealed container.

[0011] Furthermore, in S1, the temperature of the demineralized water is 15℃-30℃, and the conductivity is no greater than 10μS / cm.

[0012] Furthermore, in S2 to S4, the stirring conditions for each step are 300-500 r / min, and the stirring is continued for 10-30 min.

[0013] Furthermore, in S2 to S4, the addition rate of the stabilizer solution, corrosion inhibitor solution, and penetrant solution is controlled at 5 to 15 ml / min.

[0014] The application of a green bactericide in water treatment in the food industry includes the following steps: 1) Setting the dosage: normal dosage and intermittent dosage; 2) Dosing method: The green bactericide is added to the water to be treated through a metering pump at a dosage of 15~35mg / L; 3) Dosing location: The disinfectant should be added to the inlet pipe at the front end of the water purifier; 4) Dosage control amount: a. For normal dosage, the on-site residual chlorine monitoring device should meet the following conditions: approximately 0.3 mg / L-1.0 mg / L at the water purifier outlet and approximately 0.01-0.05 mg / L at the end of the delivery pipeline. Final result: Bacterial count in the purifier effluent <10. 5 cells / mL; b. Based on the normal dosage, if the bacterial count in the purifier's effluent is ≥10⁵ CFU / mL, adopt an intermittent dosage, once a month for 3-5 days, increasing the dosage by 20% each time; final result: bacterial count in the purifier's effluent <10⁵ CFU / mL. 5 per mL.

[0015] Furthermore, the residual chlorine detection device is an online free chlorine analyzer, which is installed at the outlet of the water purifier and at the end of the water supply pipeline. The online free chlorine analyzer monitors the residual chlorine level in the water.

[0016] Furthermore, the normal dosage is 20~35 mg / L; the intermittent dosage is 15~25% of the normal dosage for each application.

[0017] Furthermore, the normal dosage during May-October is greater than the normal dosage during November-April. The normal dosage range during May-October is 30-35 mg / L; and the normal dosage range during November-April is 20-30 mg / L.

[0018] Compared with the prior art, the advantages of the present invention are as follows: 1. This invention achieves a multi-level sterilization mechanism through the synergistic effect of penetrant and sodium hypochlorite. The bactericide molecules can penetrate the cell membrane of microorganisms, destroy their integrity, bind to enzymes in the microorganisms to inhibit their activity, and interfere with the replication and transcription of microbial DNA. This curbs the continuous reproduction of aquatic organisms in the system from the source, solves the problems of biological adhesion and insect egg blockage in pipelines and heat exchange equipment, significantly reduces the accumulation of biological slime in the system, ensures the long-term efficient operation of heat exchange equipment, and has a significantly better sterilization effect than sodium hypochlorite bactericide with a single component.

[0019] 2. The present invention uses sodium carbonate as a corrosion inhibitor, which can adjust the system to be stable and weakly alkaline. It can moderately control the oxidizing property of sodium hypochlorite and form a dense protective film on the surface of metal equipment, preventing the agent from contacting the metal substrate. While ensuring that it can kill microorganisms and multicellular organisms, it can also slow down the corrosion of water pipelines and other equipment.

[0020] 3. This invention, when combined with sodium silicate stabilizer, constructs a buffered and stable system, which can form a colloidal protective layer around the active component of sodium hypochlorite, effectively inhibiting the decomposition and loss of available chlorine. It is not easily decomposed even after long-term heat preservation at 50°C, and there is no corrosive, toxic or harmful gas volatilization or leakage. It can be stably adapted to the use scenarios where water flows through heat exchange equipment such as air coolers, filters, and pumps to raise the temperature, and the efficacy retention period is long.

[0021] 4. This invention abandons traditional organic bactericidal components such as Kathon and benzalkonium chloride, which pose safety hazards. It uses food-compatible compound raw materials throughout the process. The agents have no harmful residues and no pollution. The treated water is clean and safe, meeting the food safety requirements for production water, equipment cooling water, and sealing water in salt and other food production enterprises. Attached Figure Description

[0022] Figure 1 This is a flowchart illustrating the application of the green bactericide of this invention in water treatment within the food industry. Detailed Implementation

[0023] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0024] A green disinfectant for water treatment, comprising: By mass fraction, the analytical grade sodium hypochlorite is >7%, the penetrant is 0.01%-0.03%, the corrosion inhibitor is 0.3%-0.5%, and the stabilizer is 0.01%-0.02%. The sodium hypochlorite used was an analytical grade reagent with an effective chlorine concentration >7%. As the main bactericidal active ingredient, the mechanism of action of analytical grade sodium hypochlorite mainly includes the following aspects: 1. Sodium hypochlorite hydrolyzes in water to produce hypochlorous acid and sodium hydroxide. Hypochlorous acid further decomposes to produce nascent oxygen. Nascent oxygen has a strong oxidizing ability and can react with active substances such as proteins and enzymes in microorganisms, thereby disrupting the metabolic processes of microorganisms. 2. Hypochlorous acid molecules can penetrate the cell wall and cell membrane of microorganisms, react with the protoplasm inside the cell to cause protein denaturation and coagulation, thereby killing the microorganisms. 3. Hypochlorite ions can interact with dehydrogenases in microorganisms, blocking their respiration process and causing them to die due to interrupted energy metabolism. The higher the effective chlorine concentration, the stronger the bactericidal activity. Under the recommended dosage conditions, it can maintain effective bactericidal activity in the water.

[0025] The penetrant is a mixture of Tween-80 and EDTA, with a mass ratio of 1:1. The penetrant is added to enhance the ability of the bactericide molecules to penetrate the cell membranes of microorganisms. Its mechanism of action is as follows: Tween-80 is a hydrophilic nonionic surfactant with multiple polyoxyethylene segments and sorbitol ester groups in its molecular structure, exhibiting excellent wetting, penetration, and emulsifying properties. EDTA is an important complexing agent with four carboxyl groups and two amino groups in its molecular structure, capable of forming stable complexes with various metal ions. In this invention, the mass percentage of the penetrant is controlled within the range of 0.01% to 0.03%, with Tween-80 and EDTA each accounting for 50% of the total penetrant. Under this ratio, the penetrant achieves optimal destructive effect on the gelatinous protective film on the outer surface of aquatic organism egg masses such as snails. Tween-80 enhances the wetting and penetration ability of the bactericide solution on the cell walls of microorganisms by reducing the surface tension and interfacial tension of water. EDTA softens the gelatinous protective film on the outside of snail egg masses by complexing with metal ions such as calcium and magnesium in the water, allowing bactericidal active ingredients such as sodium hypochlorite to act directly on the embryonic tissue inside the egg masses, thereby inhibiting the reproduction of aquatic organisms from the source. This synergistic mechanism of the penetrants enables the bactericide of this invention to not only effectively kill planktonic microorganisms, but also effectively kill biofilms attached to the surface of equipment and aquatic reproductive organisms hidden in the egg masses.

[0026] Different bactericides were added to water samples containing microorganisms, and the bactericidal effect was measured after a certain period of contact, as shown in Table 1. The test results show that, at the recommended concentration, the bactericides have good killing effects on bacteria, fungi, and algae, with a sterilization rate of over 99%.

[0027] Table 1. Sterilization Effect Table

[0028] The corrosion inhibitor used is sodium carbonate, with its mass percentage controlled within the range of 0.3% to 0.5%. The addition of the corrosion inhibitor suppresses the corrosive effect of sodium hypochlorite on metal equipment. Its mechanism of action is as follows: 1. Sodium carbonate can react with sodium hypochlorite to produce sodium carbonate and hypochlorite ions. Adjusting the pH of the solution to a weakly alkaline range, under this pH condition, the oxidizing property of sodium hypochlorite is moderately inhibited, thereby reducing the corrosion rate of metallic materials. 2. Carbonate ions can form a dense protective carbonate film on the surface of metal materials such as carbon steel, stainless steel, and copper. This film can effectively prevent sodium hypochlorite from directly contacting the metal substrate. 3. The addition of sodium carbonate can consume some of the sodium hypochlorite, reducing the direct reaction between active chlorine and the metal surface, thereby protecting the equipment from corrosion damage.

[0029] Different concentrations of bactericide were applied to metal materials to observe corrosion. A rotating plate apparatus was used, with natural reservoir water as the raw water. The corrosion rate was calculated using the mass loss of a standard carbon steel test piece ((50.0±0.1)mm*(25.0±0.1)mm*(2.0±0.1)mm). The test lasted 72 hours. The corrosion rate (…) (%,%), calculation formula: ; In the formula: V0—The numerical value of the corrosion rate of the blank test piece, in millimeters per year (mm / a). V1—The numerical value of the corrosion rate of the test piece, in millimeters per year (mm / a).

[0030] As shown in Table 2, different concentrations of the agent have virtually no effect on the corrosion rate of carbon steel. The test results indicate that the bactericide is non-corrosive to equipment materials and safe to use under the recommended concentration conditions.

[0031] Table 2 Corrosion Rate and Corrosion Indices

[0032] The stabilizer used is sodium silicate, with its mass percentage controlled within the range of 0.01% to 0.02%. The stabilizer is added to maintain the stability of the various components of the bactericide and prevent the decomposition of available chlorine. Its stabilization mechanism is as follows: 1. Sodium silicate hydrolyzes in water to produce silicic acid and sodium hydroxide. The silicic acid produced further polymerizes to form silicic acid sol. This sol has high dispersibility and adhesion, and can form a protective colloidal film around sodium hypochlorite molecules, effectively preventing the decomposition and escape of hypochlorite ions. 2. The alkaline environment of sodium silicate is conducive to maintaining the stability of sodium hypochlorite, because the decomposition rate of sodium hypochlorite under alkaline conditions is significantly lower than that under acidic or neutral conditions. 3. When sodium silicate and sodium carbonate are used together, they can form a more stable buffer system, further improving the overall chemical stability of the bactericide.

[0033] The bactericide was prepared using deionized water and heated. Steam was introduced into a 0.1 mol / L solution. The bactericide was tested under heating conditions, and its decomposition was observed. The test results are shown in Table 3. When the temperature was raised to 50℃, the bactericide did not decompose to produce corrosive gases or volatilize harmful gases, and it has good thermal stability.

[0034] Table 3. Table for Residual Chlorine Detection in Water

[0035] The preparation method of the green bactericide for water treatment includes the following steps: S1. Add the penetrant, corrosion inhibitor, and stabilizer to the demineralized water and stir until completely dissolved to prepare a mixed auxiliary agent solution. The preparation order of the mixed auxiliary agent solution is to first add the stabilizer and corrosion inhibitor to the demineralized water, and then add the penetrant after they are completely dissolved. This preparation order can ensure that the penetrant maintains maximum activity when mixed with sodium hypochlorite in the subsequent process. The specific operation is as follows: Take a certain amount of demineralized water and place it in a preparation tank. The temperature of the demineralized water should be controlled within the range of 15-30℃, and the conductivity should not exceed 10μS / cm to ensure the purity of the preparation water. Then, add the pre-weighed sodium silicate stabilizer to the demineralized water, turn on the stirring device and stir at a speed of 200-400 r / min for 5-10 min until the sodium silicate is completely dissolved to form a uniform transparent solution. Next, add the pre-weighed sodium carbonate corrosion inhibitor to the demineralized water with the stabilizer added, and continue stirring for 5-10 min to completely dissolve the sodium carbonate. Finally, add the pre-prepared penetrant to the mixed solution slowly under low-speed stirring conditions, at a speed of 100-200 r / min for 3-5 min to avoid excessive foaming of the surfactant due to excessive stirring. The entire preparation process should be carried out under light-protected conditions.

[0036] S2. Under stirring conditions, the mixed auxiliary agent solution prepared in step S1 is added sequentially to the analytical grade sodium hypochlorite solution. The specific operation steps are as follows: Add the required amount of analytical grade sodium hypochlorite solution to the compounding tank. The effective chlorine concentration of the analytical grade sodium hypochlorite should be >7%. The specific amount is determined according to the effective chlorine concentration requirements of the target product. Then, turn on the stirring device and slowly add the mixed auxiliary agent solution prepared in S1 to the sodium hypochlorite solution through a metering pump under stirring conditions. The stirring speed is controlled at 300-500 r / min, and the addition time of the mixed auxiliary agent solution is controlled at 5-10 min. After the addition is completed, continue stirring for 10-20 min to ensure that the components are fully contacted and reacted. After the stirring is completed, stop stirring and let the mixture stand for 30 minutes to allow the chemical reaction between the components to reach equilibrium and allow the bubbles to escape fully. The solution temperature should be strictly controlled during the compounding process. The temperature rise will accelerate the decomposition of effective chlorine. Therefore, if necessary, the compounding tank should be cooled to keep the solution temperature below 30℃.

[0037] S3. Filter the mixture that has been left to stand in S2, and fill and seal the filtrate to obtain the finished green bactericide. The specific operation is as follows: After settling, the mixture is pumped into a filter for filtration. The filter uses a polypropylene pleated filter element or a ceramic filter element with a pore size of 1-5 μm. The filtration precision is sufficient to effectively remove insoluble impurities, suspended particles, and any microorganisms that may be present in the solution. During the filtration process, an appropriate filtration pressure should be maintained, controlled within the range of 0.1-0.3 MPa. The filtration speed is judged by the clarity and transparency of the filtrate. The filtered filtrate is temporarily stored in an intermediate storage tank before being bottled and sealed. The filling containers are light-proof, sealed barrels or bottles made of materials such as polyethylene or polyvinylidene fluoride. Finally, a product label is affixed to the outer wall of the container, indicating the product name, preparation date, effective chlorine concentration, net content, and safety precautions.

[0038] The application of green bactericides in water treatment in the food industry involves quantitatively adding the green bactericide to the cooling water or sealing water of food industry equipment using metering equipment. The equipment configuration for addition is shown in Table 4, and the specific application method is as follows: The bactericide is added to the inlet pipe at the front end of the water purifier. A digital display metering pump is used to quantitatively add the green bactericide to the inlet pipe at the front end of the water purifier. The metering pump has a working pressure of >3kg / cm², a flow rate of >4L / h, and a metering accuracy of ±1%. It is configured with one pump in use and one in standby. The dosing pipeline is made of PVC or HDPE material, with a total length of about 150 meters. The disinfectant storage tank is equipped with a tank pump with a power of not less than 800W for extraction and transportation. The flow rate of the tank pump should be greater than the maximum flow rate of the metering pump. Online free chlorine analyzers are installed at the outlet of the water purifier and at the end of the water supply pipeline, with a monitoring range of 0-5 mg / L. These analyzers monitor the residual chlorine concentration in the water in real time and feed it back to the control system. The residual chlorine concentration control range at the water purifier outlet is a preset range, and the residual chlorine concentration control range at the end of the water supply pipeline is a preset range. The dosage is automatically adjusted based on the residual chlorine values. The residual chlorine at the water purifier outlet is controlled at 0.15-0.35 mg / L, and the residual chlorine at the end of the water supply pipeline is controlled at 0.01-0.05 mg / L. When the detected value is below the lower limit, the operating frequency of the metering pump should be automatically increased; when the detected value is above the upper limit, the operating frequency of the metering pump should be automatically decreased or the dosing should be suspended. A third online free chlorine analyzer is installed inside the water purifier to monitor the changes in residual chlorine during the treatment process, facilitating the evaluation of the sterilization effect. The online free chlorine analyzer should be calibrated regularly, generally every 1 to 2 weeks. Calibration is performed using a standard residual chlorine solution at two points to ensure the accuracy and reliability of the measurement data. The dosage of green bactericide is set as a normal dosage and an intermittent dosage. The intermittent dosage is once a month for 3-5 days, with an increase of 20% in dosage. The dosage is dynamically adjusted according to the season: the normal dosage is 21.5 mg / L, the dosage during the high-temperature period from May to October is 25 mg / L, and the dosage during the low-temperature period from November to April of the following year is a trace amount or discontinued; when the effluent bacterial count is ≥10... 5 When the concentration is 1 / mL, temporarily increase the dosage by 20%.

[0039] Table 4 Equipment Configuration Table

[0040] In a practical application scenario, taking a salt production enterprise as an example, the enterprise produces 1.5 million tons of salt annually and requires approximately 300 cubic meters of fresh water per hour daily. The enterprise uses the green bactericide and sterilization method described in this invention for water treatment. The specific implementation steps are as follows: First, prepare the green disinfectant product according to the above steps S1-S3. Then, install a digital display metering pump on the inlet pipe at the front end of the water purifier. Set the flow rate of the metering pump to match the designed dosage. Control the dosage speed of the disinfectant by adjusting the operating frequency of the metering pump. Start the metering pump to begin dosing. The disinfectant is delivered to the dosing point on the inlet pipe through the dosing pipeline. After being fully mixed with the water to be treated, it enters the water purifier for treatment. During the treatment process, the residual chlorine concentration at the outlet of the water purifier and the end of the water pipeline is monitored in real time by an online free chlorine analyzer. The operating parameters of the metering pump are adjusted according to the monitoring data to keep the residual chlorine concentration within the set range. Regularly collect water samples for total bacterial count and heterotrophic bacteria count to assess whether the sterilization effect has achieved the expected goals.

[0041] Based on the results of production debugging and verification throughout the year, as shown in Table 5, after adopting the bactericide and sterilization method described in this invention, the bacterial count decreased from the original 10 in the summer. 8 -10 9 cells / mL, 10 in winter 5 -10 6 The concentration of cells / mL steadily decreased to 10. 3 -10 5 The concentration of cells / mL is significantly effective in sterilization. Visually, there is no obvious algae growth on the surface of the water purifier tank, indicating that algae pollution is effectively controlled. There is virtually no snail growth in the pipes and heat exchanger heads, and there is no longer any situation where snail shells clog the heat exchange equipment. The amount of biological slime in the system is significantly reduced, the surface of the heat exchanger is clean, and the heat exchange efficiency is significantly improved. The industrial water at the end is free of toxic and harmless components and residues, and the water quality indicators meet the relevant standards.

[0042] Table 5. Aquatic Bacterial Count and Residual Chlorine Content

[0043] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention.

Claims

1. A green bactericide for water treatment, characterized in that, By mass fraction, it contains the following components: analytical grade sodium hypochlorite >7%, penetrant 0.01%-0.03%, corrosion inhibitor 0.3%-0.5%, stabilizer 0.01%-0.02%, and the balance is demineralized water; The penetrant is a mixture of Tween-80 and ethylenediaminetetraacetic acid; The corrosion inhibitor used is sodium carbonate; The stabilizer used is sodium silicate.

2. The green bactericide for water treatment according to claim 1, characterized in that, The mass ratio of Tween-80 to ethylenediaminetetraacetic acid is 1:

1.

3. A method for preparing a green bactericide for water treatment as described in any one of claims 1-2, characterized in that, Includes the following steps: S1. Prepare single-component solutions of stabilizer sodium silicate, corrosion inhibitor sodium carbonate and penetrant using demineralized water. S2. Slowly add the prepared stabilizer solution to the analytical grade sodium hypochlorite solution while stirring. S3. Slowly add the prepared corrosion inhibitor solution to the mixed solution obtained in S2, and continue stirring; S4. Slowly add the prepared penetrant solution to the mixed solution obtained in S3, continue stirring, and let it stand after mixing to obtain the mixed solution; S5. Filter the mixture that has been left to stand in S4, and fill the filtrate into a light-proof, sealed container.

4. The method for preparing the green bactericide for water treatment according to claim 3, characterized in that, In S1, the temperature of the demineralized water is 15℃-30℃, and the conductivity is no greater than 10μS / cm.

5. The method for preparing the green bactericide for water treatment according to claim 3, characterized in that, In steps S2 to S4, the stirring conditions for each step are 300-500 r / min, and the stirring is continued for 10-30 min.

6. The method for preparing the green bactericide for water treatment according to claim 3, characterized in that, In S2 to S4, the addition rate of the stabilizer solution, corrosion inhibitor solution, and penetrant solution is controlled at 5 to 15 ml / min.

7. The application of the green bactericide according to any one of claims 3 to 6 in water treatment in the food industry, characterized in that, Includes the following steps: 1) Setting the dosage: normal dosage and intermittent dosage; 2) Dosing method: The green bactericide is added to the water to be treated through a metering pump at a dosage of 15~35mg / L; 3) Dosing location: The disinfectant should be added to the inlet pipe at the front end of the water purifier; 4) Dosage control amount: a. For normal dosage, the on-site residual chlorine monitoring device should meet the following standards: approximately 0.3 mg / L-1.0 mg / L at the water purifier outlet and approximately 0.01-0.05 mg / L at the end of the delivery pipeline. Final result: Bacterial count in the purifier effluent <10. 5 cells / mL; b. Based on the normal dosage, if the bacterial count in the purifier's effluent is ≥10⁵ CFU / mL, adopt an intermittent dosage, once a month for 3-5 days, increasing the dosage by 20% each time; final result: bacterial count in the purifier's effluent <10⁵ CFU / mL. 5 per mL.

8. The application of the green bactericide according to claim 7 in water treatment in the food industry, characterized in that, The residual chlorine detection device is an online free chlorine analyzer, which is installed at the outlet of the water purifier and at the end of the water supply pipeline. The online free chlorine analyzer monitors the residual chlorine level in the water.

9. The application of the green bactericide according to claim 7 in water treatment in the food industry, characterized in that, The normal dosage is 20~35 mg / L; the intermittent dosage is 15~25% of the normal dosage for each application.

10. The application of the green bactericide according to claim 9 in water treatment in the food industry, characterized in that, The normal dosage during May-October is higher than that during November-April. The normal dosage range during May-October is 30-35 mg / L; the normal dosage range during November-April is 20-30 mg / L.

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