Fungicide for external cooling circulating water system of phase modifier as well as compounding method and application of bactericide

Abstract

The invention discloses a bactericide for an external cooling circulating water system of a phase modifier as well as a compounding method and application of the bactericide, and particularly relates to the technical field of water treatment. The invention provides a compound bactericide for an external cold circulating water system of a phase modifier. Main active components of the compound bactericide comprise quinoline quaternary ammonium salt and / or a derivative thereof, and isothiazolinone and / or a derivative thereof; the compounding ratio of the quinoline quaternary ammonium salt and / or the derivative thereof to the isothiazolinone and / or the derivative thereof is (10-150mL): (5-10mg). When in use, the quinoline quaternary ammonium salt (or the derivative thereof) and the isothiazolinone (or the derivative thereof) are added into the phase modifier external cold circulating water and are uniformly stirred. Quinoline quaternary ammonium salt (or a derivative thereof) changes permeability by adsorbing bacterial surfaces, isothiazolinone (or a derivative thereof) realizes sterilization by destroying microbial cell membrane protein bonds and enzymatic activity, and the quinoline quaternary ammonium salt and the isothiazolinone are compounded to block different metabolic pathways at the same time, so that a synergistic sterilization effect is achieved.

Description

Technical Field

[0001] This invention relates to the field of water treatment technology, specifically to a bactericide for a condenser external cooling circulating water system, its compounding method, and its application. Background Technology

[0002] The external cooling water system of a synchronous condenser is one of the key infrastructures for ensuring the efficient operation of a converter station. Its core function is to reduce equipment temperature through heat exchange, ensuring the converter station operates in a safe and stable state. However, during the long-term operation of the circulating cooling water, the suitable water temperature, abundant nutrients, and sufficient oxygen create ideal conditions for the growth of microbial communities, forming biofilms on the surfaces of stainless steel pipes and heat exchangers. This microbial contamination not only exacerbates the corrosion of stainless steel pipes and reduces heat transfer efficiency but may also lead to equipment failure or public health issues. For example, the metabolic products of heterotrophic bacteria can accelerate pitting and under-deposit corrosion of metal materials; furthermore, excessive levels of pathogens can spread into the environment through aerosols from the cooling system, threatening public health. However, the use of single bactericides may result in low bactericidal rates and the risk of drug resistance. Therefore, developing efficient and environmentally friendly bactericidal technologies through compound synergistic mechanisms has become an important research direction in the field of synchronous condenser cooling water treatment.

[0003] Several patents already exist regarding the research on bactericides for circulating cooling water systems. Patent CN108990997A discloses a method for preparing a composite non-oxidizing bactericide and algaecide involving modified dodecyl dimethyl benzyl ammonium chloride and a composite oxidizing bactericide and algaecide involving sodium bromide-modified sodium hypochlorite. This method treats circulating cooling water systems using an alternating dosing method, making it suitable for industrial circulating cooling water systems and swimming pool applications. It has a wide applicable pH range and a slime-removing function. However, the bactericide and algaecide in this patent contains chlorine and bromine, which can easily cause corrosion to the stainless steel pipes of the external cooling circulating water system of a camera condenser.

[0004] Patent CN1480043A discloses a compound bactericide for water treatment and its preparation method. It uses chlorine, sodium chloride, sulfuric acid, and lime—commonly used in water treatment—as raw materials, employing basic chemical methods to produce a highly efficient, broad-spectrum, and low-toxicity fourth-generation bactericide. This bactericide can be directly used for treating drinking water, industrial circulating water, oilfield injection water, and domestic and industrial wastewater. It represents a convenient and inexpensive upgrade for water treatment bactericides and is also suitable for some immediate disinfection applications. However, the compound bactericide in this patent also contains chlorine, which can easily cause corrosion to the stainless steel pipes of the external cooling circulating water system of a camera condenser.

[0005] Patent CN101973612A discloses a reactive compound multifunctional water treatment agent and its preparation and application methods. The reactive compound multifunctional water treatment agent comprises the following components in the following weight ratio: sodium chlorite: ferric sulfate: borax: itaconic acid = 1:0.8-1.5:0.01-0.03:0.05-0.1. When this agent is added to wastewater, a chemical reaction occurs between the components. The reaction products or intermediate products have bactericidal, flocculating, and adsorbing effects. Combined with the compounding effect of other components, this water treatment agent simultaneously possesses four functions: bactericidal, flocculating, adsorbing, and scale inhibition. However, this formula contains sodium chlorite, and itaconic acid is acidic. Adding it to a circulating cold water system could potentially corrode stainless steel pipes and equipment, affecting equipment safety and lifespan.

[0006] A review of relevant patent literature reveals that, in order to prevent or mitigate the problem of bacterial growth in the external cooling circulating water system of a condenser, it is necessary to specifically screen and compound highly efficient, environmentally friendly bactericides and algaecides based on the types of bacteria in the external cooling water and the characteristics of stainless steel pipes being susceptible to halogen ion corrosion, thereby preventing the growth of bacteria and algae in the external cooling water system. Summary of the Invention

[0007] The technical problem to be solved by this invention is how to prevent or slow down the growth of bacteria in the external cooling circulating water system of a camera condenser, and to selectively screen and compound highly efficient and environmentally friendly bactericides and algaecides.

[0008] The present invention solves the above-mentioned technical problems through the following technical means: This invention proposes a compound bactericide for the external cooling circulating water system of a condenser, the main active ingredients of which include quinoline quaternary ammonium salt and / or its derivatives, isothiazolinone and / or its derivatives; the compounding ratio of the quinoline quaternary ammonium salt and / or its derivatives, isothiazolinone and / or its derivatives is 10~150mL: 5~10mg.

[0009] Preferably, the quinoline quaternary ammonium salt derivative refers to one or more of indoleazine derivatives and aralkyl-substituted 1-methylquinoline quaternary ammonium salts.

[0010] Preferably, the isothiazolinone derivative refers to one or more of 5-chloro-2-methylisothiazolinone and 2-methylisothiazolinone.

[0011] Preferably, the main active ingredient consists of quinoline quaternary ammonium salt and / or its derivatives, isothiazolinone and / or its derivatives.

[0012] Preferably, the main active ingredients are composed of quinoline quaternary ammonium salt and isothiazolinone.

[0013] Preferably, the compounding ratio of the quinoline quaternary ammonium salt and / or its derivatives, and the isothiazolinone and / or its derivatives is 30~130mL:6~8mg.

[0014] Preferably, the compounding ratio of the quinoline quaternary ammonium salt and / or its derivatives, and the isothiazolinone and / or its derivatives is 10~100mL: 5~7mg.

[0015] Preferably, the compounding ratio of the quinoline quaternary ammonium salt and / or its derivatives, and the isothiazolinone and / or its derivatives is 90~130mL: 6.8~10mg.

[0016] Preferably, the compounding ratio of the quinoline quaternary ammonium salt and / or its derivatives, and the isothiazolinone and / or its derivatives is 150 mL: 10 mg.

[0017] The present invention also proposes a method for compounding the above-mentioned compound bactericide, comprising the following steps: weighing each component according to the above-mentioned compounding ratio and compounding them to obtain the product.

[0018] The present invention also proposes the application of the above-mentioned compound bactericide in the sterilization of the external cooling circulating water system of a condenser.

[0019] The present invention also proposes a method for using the above-mentioned compound bactericide in the external cooling circulating water system of the condenser, comprising the following steps: storing quinoline quaternary ammonium salt and / or its derivatives, and isothiazolinone and / or its derivatives separately; when using, adding quinoline quaternary ammonium salt and / or its derivatives, and isothiazolinone and / or its derivatives to the external cooling circulating water of the condenser, and stirring evenly.

[0020] Preferably, the ratio of quinoline quaternary ammonium salt and / or its derivatives, isothiazolinone and / or its derivatives, and external cooling circulating water of the condenser is 10~150mL: 5~10mg: 0.8~1.5L; more preferably, it is 150mL: 10mg: 1L.

[0021] The beneficial effects of this invention are as follows: 1. The present invention discloses a compound bactericide for a condenser external cooling circulating water system. One of the raw materials used is a quinoline quaternary ammonium salt, which has excellent water solubility, good chemical stability, and can maintain its chemical properties unchanged over a wide pH range. It also exhibits high thermal stability and good biodegradability, making it environmentally friendly. The other raw material used is isothiazolinone, which has a solubility of 480 ppm in water at 25°C. It is biodegradable and exerts its bactericidal effect by breaking the bonds of bacterial and algal proteins. Upon contact with microorganisms, it can rapidly and irreversibly inhibit their growth, leading to the death of microbial cells. Moreover, neither of these bactericides contains halogens and will not cause potential corrosion to stainless steel pipes. Therefore, the compound bactericide for a condenser external cooling circulating water system of the present invention is a green and highly efficient bactericide with good water solubility, stable chemical properties, biodegradability, high bactericidal efficiency, and no corrosive hazards.

[0022] 2. Addressing the challenges posed by diverse bacterial types in external cooling water and the vulnerability of stainless steel pipes to halide ion corrosion, this invention proposes a compounding method for a bactericide in a condenser's external cooling circulating water system. Quinoline quaternary ammonium salt (or its derivatives) alters permeability by adsorbing onto bacterial surfaces, while isothiazolinone (or its derivatives) achieves bactericidal effects by disrupting microbial cell membrane protein bonds and enzyme activity. The compounding of these two compounds simultaneously blocks different metabolic pathways, resulting in a synergistic bactericidal effect. The quinoline quaternary ammonium salt and / or its derivatives are compounded with isothiazolinone and / or its derivatives at a ratio of 10-150 mL: 5-10 mg. This compounding method broadens the applicable pH range of the system to 4-9, preventing bactericide inactivation due to acid-base imbalance, improving safety, and ultimately preventing the growth of bacteria and algae in the condenser's external cooling water system.

[0023] Of course, implementing any product or method of the present invention does not necessarily require achieving all of the advantages described above at the same time. Attached Figure Description

[0024] Figure 1 The bactericidal rates of different concentrations of single quinoline quaternary ammonium salts against heterotrophic bacteria in Comparative Examples 1-3 of this invention are shown. Figure 2 The bactericidal rate of isothiazolinone (final concentration 10 mg / L) + quinoline quaternary ammonium salt (final concentrations 10 mL / L, 50 mL / L, 100 mL / L and 150 mL / L) against heterotrophic bacteria in Examples 1-4 of the present invention; Figure 3 The bactericidal rate of isothiazolinone (final concentration 1 mg / L) + quinoline quaternary ammonium salt (final concentration 50 mL / L) against heterotrophic bacteria in Comparative Example 4 of this invention is shown. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Unless otherwise defined, the technical terms used below have the same meaning as understood by those skilled in the art.

[0026] Unless otherwise specified, the test materials and reagents used in the following examples are commercially available or prepared by known methods.

[0027] Unless otherwise specified, all techniques or conditions described in the embodiments can be performed in accordance with the techniques or conditions described in the literature in this field or in the product manual. Unless otherwise specified, the quantitative experiments in the following embodiments are all repeated three times or more, and the results are averaged.

[0028] Example 1: The preparation of a compound fungicide consisting of quinoline quaternary ammonium salt (QM) and isothiazolinone (IT) includes the following steps: (1) Heterotrophic bacteria culture Based on the quality of the external cooling water of the condenser, heterotrophic bacteria were cultured according to the composition table of the heterotrophic bacteria culture medium in Table 1.

[0029] Table 1. Composition of Heterotrophic Bacterial Culture Medium

[0030] First, the culture medium for heterotrophic bacteria was prepared; the composition of the medium is shown in Table 1. Before the inoculation experiment, all equipment used, including triangular rods, flasks, pipette tips, and the culture medium, were sterilized at 121°C for 20 minutes. Disposable sterile culture dishes were used. During the inoculation experiment, a sterilization experimental group and a control group without any reagents were set up. A control group containing only the culture medium was also set up to demonstrate that the procedure was performed under aseptic conditions. All operations were conducted in a sterile cabinet.

[0031] (2) Prepare a compound bactericide of 10 mg isothiazolinone (IT) + 10 mL quinoline quaternary ammonium salt (QM) and add it to the 1L external cooling circulating water of the camera that has been cultured with heterotrophic bacteria. The final concentrations of isothiazolinone (IT) and quinoline quaternary ammonium salt (QM) are 10 mg / L and 10 mL / L, respectively.

[0032] The bactericidal rate against heterotrophic bacteria was tested 4 hours after the addition of the compound bactericide.

[0033] (3) Calculation of sterilization rate The sterilization rate was calculated using Formula 1, by comparing the change in bacterial count before and after sterilization: In the formula, A Sterilization rate; C The number of bacteria without the addition of bactericides; C 0 represents the number of bacteria after sterilization.

[0034] Example 2: The difference between this embodiment and embodiment 1 is that in step (2), a compound bactericide of 10 mg isothiazolinone (IT) + 50 mL quinoline quaternary ammonium salt (QM) is prepared, and the rest is the same as in embodiment 1.

[0035] Example 3: The difference between this embodiment and embodiment 1 is that in step (2), a compound bactericide of 10 mg isothiazolinone (IT) + 100 mL quinoline quaternary ammonium salt (QM) is prepared, and the rest is the same as in embodiment 1.

[0036] Example 4: The difference between this embodiment and embodiment 1 is that in step (2), a compound bactericide of 10 mg isothiazolinone (IT) + 150 mL quinoline quaternary ammonium salt (QM) is prepared, and the rest is the same as in embodiment 1.

[0037] Comparative Example 1: The difference between this comparative example and Example 1 is that in step (2), 10 mL of quinoline quaternary ammonium salt (QM) bactericide is prepared, and the rest is the same as in Example 1.

[0038] Comparative Example 2: The difference between this comparative example and Example 1 is that in step (2), 50 mL of quinoline quaternary ammonium salt (QM) bactericide is prepared, and the rest is the same as in Example 1.

[0039] Comparative Example 3: The difference between this comparative example and Example 1 is that in step (2), 100 mL of quinoline quaternary ammonium salt (QM) bactericide is prepared, and the rest is the same as in Example 1.

[0040] Comparative Example 4: The difference between this comparative example and Example 1 is that in step (2), a compound bactericide of 1 mg isothiazolinone (IT) + 50 mL quinoline quaternary ammonium salt (QM) is prepared, and the rest is the same as in Example 1.

[0041] The bactericidal effect of Comparative Example 4 is as follows Figure 3 As shown, the sterilization rate is significantly reduced when the ratio is changed.

[0042] Determination of the bactericidal rate of a single quinoline quaternary ammonium salt (QM): like Figure 1As shown in the figure, the bactericidal rate of different concentrations of single quinoline quaternary ammonium salt against heterotrophic bacteria in Comparative Examples 1-3 is as follows: as the final concentration of quinoline quaternary ammonium salt in the external cooling circulating water of the condenser gradually increases from 10 mL / L to 100 mL / L, the bactericidal rate gradually increases from 6% to 56%, and quinoline quaternary ammonium salt exhibits good bactericidal performance.

[0043] Detection of bactericidal rates of different compound ratios of isothiazolinone (IT) and quinoline quaternary ammonium salt (QM) like Figure 2 As shown, isothiazolinone (final concentration 10 mg / L) + quinoline quaternary ammonium salt (final concentrations 10 mL / L, 50 mL / L, 100 mL / L and 150 mL / L) has a high bactericidal rate against heterotrophic bacteria, reaching 95%, 96%, 97% and 98% respectively. The bactericidal rate of the compound bactericide in the embodiments of the present invention is much higher than that of single quinoline quaternary ammonium salt (QM) and the compound bactericide with unbalanced ratio in Comparative Example 4.

[0044] Therefore, adding isothiazolinone (IT) or a compound bactericide consisting of quinoline quaternary ammonium salt (QM) to the external cooling water system of a condenser can achieve a good bactericidal effect.

[0045] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A compound bactericide for a synchronous condenser external cooling circulating water system, characterized in that, The main active ingredients include quinoline quaternary ammonium salt and / or its derivatives, isothiazolinone and / or its derivatives; the compounding ratio of the quinoline quaternary ammonium salt and / or its derivatives, isothiazolinone and / or its derivatives is 10~150mL: 5~10mg.

2. The compound bactericide according to claim 1, characterized in that, Quinoline quaternary ammonium salt derivatives refer to one or more of indoleazine derivatives and aralkyl-substituted 1-methylquinoline quaternary ammonium salts; isothiazolinone derivatives refer to one or more of 5-chloro-2-methylisothiazolinone and 2-methylisothiazolinone.

3. The compound bactericide according to claim 1, characterized in that, The compounding ratio of the quinoline quaternary ammonium salt and / or its derivatives, and isothiazolinone and / or its derivatives is 30~130mL:6~8mg.

4. The compound bactericide according to claim 1, characterized in that, The compounding ratio of the quinoline quaternary ammonium salt and / or its derivatives, and isothiazolinone and / or its derivatives is 10~100mL: 5~7mg.

5. The compound bactericide according to claim 1, characterized in that, The compounding ratio of the quinoline quaternary ammonium salt and / or its derivatives, and isothiazolinone and / or its derivatives is 90~130mL: 6.8~10mg.

6. The compound bactericide according to claim 1, characterized in that, The compounding ratio of the quinoline quaternary ammonium salt and / or its derivatives, and isothiazolinone and / or its derivatives is 150 mL: 10 mg.

7. The method for compounding the compound bactericide according to any one of claims 1-6, characterized in that, Includes the following steps: Weigh each component according to the above compounding ratio and compound them to obtain the final product.

8. The application of the compound bactericide according to any one of claims 1-6 or the compound bactericide obtained by the compounding method according to claim 7 in the sterilization of the external cooling circulating water system of a condenser.

9. The method of using the compound bactericide according to any one of claims 1-6, characterized in that, Includes the following steps: Store quinoline quaternary ammonium salt and / or its derivatives, and isothiazolinone and / or its derivatives separately. When using, add quinoline quaternary ammonium salt and / or its derivatives, and isothiazolinone and / or its derivatives to the external cooling circulating water of the condenser and stir until homogeneous.

10. The method of use according to claim 9, characterized in that, The ratio of quinoline quaternary ammonium salt and / or its derivatives, isothiazolinone and / or its derivatives, and external cooling circulating water of the condenser is 10~150mL: 5~10mg: 0.8~1.5L; more preferably 150mL: 10mg: 1L.

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