Potassium hydrogen persulfate and sodium chloride composite slow-release disinfectant as well as preparation method and application thereof

Abstract

The invention provides a potassium hydrogen persulfate and sodium chloride composite slow-release disinfectant as well as a preparation method and application thereof, and belongs to the technical field of disinfection and sterilization. The composite slow-release disinfectant is composed of potassium hydrogen persulfate microcapsules and sodium chloride microcapsules; the potassium hydrogen persulfate microcapsules and the sodium chloride microcapsules are prepared by respectively taking potassium hydrogen persulfate and sodium chloride as core materials and coating the core materials with an ethanol solution of a wall material. According to the invention, potassium hydrogen persulfate and sodium chloride are respectively coated, so that the problems of deliquescence, poor slow release effect and the like are solved, and the purposes of stable storage and disinfection aging prolonging are achieved; in addition, an aqueous solution is not used during coating, so that the problem of failure caused by reaction of potassium hydrogen persulfate in water is avoided. The method is simple in process, easy to control, almost free of loss of raw materials and high in conversion rate.

Description

Technical Field

[0001] The invention belongs to the technical field of disinfection and sterilization, and relates to a potassium persulfate and sodium chloride composite slow-release disinfectant and a preparation method and application thereof. Background Art

[0002] Potassium persulfate complex salt, with the molecular formula of 2KHSO5·KHSO4·K2SO4, abbreviated as PMPS, is a fifth-generation new type of active oxygen disinfectant with very strong oxidation ability. Potassium persulfate complex salt releases strong oxygen ions when it comes into contact with water. After compounding with sodium chloride, the strong oxygen ions will oxidize the chloride ions in the sodium chloride to produce chlorine gas, and finally generate sodium hypochlorite, which further enhances the disinfection effect. Compared with other disinfectants, potassium persulfate and sodium chloride complex salt has the functions of acid disinfection, halogen disinfection, and oxidation disinfection. It has the characteristics of high efficiency, broad spectrum, rapid and long-lasting, and safe. It kills various microorganisms including bacteria, fungi, protozoa and viruses more thoroughly, and is widely used in livestock and poultry breeding, water disinfection and other fields.

[0003] However, potassium persulfate is easy to deliquesce and will react weakly when it encounters moisture in the air, thereby reducing the sterilization and disinfection effect. Therefore, the storage conditions are harsh and the storage period is short. At present, it is generally coated in the form of microcapsules to improve its stability. In addition, potassium persulfate reacts quickly when it encounters water, which is not conducive to the long-term effectiveness of disinfection. After microencapsulation, it can also achieve a sustained release effect.

[0004] Chinese invention patent CN113207906B discloses a slow-release long-acting potassium persulfate disinfectant and a method for making the same. The triple salt formed by combining potassium monopersulfate with potassium hydrogen sulfate and potassium sulfate is used as the core material, and polymethacrylate I and polyacrylic resin IV are used as the wall materials. The potassium persulfate composite salt inclusion compound is prepared by boiling granulation. Compared with the common potassium persulfate disinfectant containing unencapsulated potassium monopersulfate composite salt, the method has stable performance, is not easy to deliquesce, and has a long sterilization time. However, the method needs to use two wall materials in sequence, and involves the control of parameters such as temperature and air volume, and has a complicated process and high cost.

[0005] Chinese invention patent application CN110839622A discloses a potassium persulfate sustained-release agent and its preparation method and application, wherein potassium persulfate aqueous solution is used as the core material and polypyrrole is used as the wall material, and potassium persulfate-polypyrrole microcapsules are prepared by in-situ polymerization, which greatly improves the stability of potassium persulfate, facilitates storage and transportation, significantly prolongs the drug release time, and improves the drug utilization rate. However, this method uses potassium persulfate aqueous solution as the core material, and potassium persulfate will be consumed during the preparation process due to the reaction between potassium persulfate and water.

[0006] In addition, microencapsulation of sodium chloride can achieve a sustained release effect of the two main reaction substances at the same time, thereby prolonging the duration of the disinfection effect. For example, Chinese invention patent CN105360162B discloses a composite potassium persulfate powder disinfectant and a preparation method thereof, which uses a polymer sustained-release carrier such as starch and polyacrylic acid resin to encapsulate sodium chloride, thereby avoiding the reaction between sodium chloride and potassium persulfate, improving the stability of the disinfectant, and not being easy to deliquesce. However, potassium persulfate will still release strong oxygen ions after contacting water.

[0007] In summary, the existing potassium persulfate disinfectants still have problems such as easy deliquesce and poor sustained-release effect after potassium persulfate complex salt is compounded with sodium chloride; and potassium persulfate reacts when it comes into contact with water, so most coating methods involving the preparation of aqueous solutions are not suitable for potassium persulfate. Therefore, the coating technology involving potassium persulfate aqueous solution also needs to be further improved. Summary of the invention

[0008] Aiming at the problems existing in the prior art that the compound of potassium persulfate compound salt and sodium chloride is easy to deliquesce and has poor sustained-release effect, the present invention coats the potassium persulfate compound salt and sodium chloride respectively to achieve storage stability and extend the disinfection time.

[0009] To achieve the above object, the technical solution of the present invention is as follows:

[0010] The invention provides a potassium persulfate and sodium chloride composite sustained-release disinfectant, which consists of potassium persulfate microcapsules and sodium chloride microcapsules; the potassium persulfate microcapsules and the sodium chloride microcapsules are prepared by using potassium persulfate and sodium chloride as core materials, respectively, and coating with an ethanol solution of a wall material.

[0011] The wall material is selected from one or more of ethyl cellulose, butyl cellulose and rosin.

[0012] Preferably, the mass ratio of potassium persulfate and sodium chloride to the wall material is 4:1-20:1, and the specific mass ratio includes but is not limited to: 25:1, 25:3 and 25:4; preferably 25:4.

[0013] Preferably, the concentration of the ethanol solution of the wall material is 4-8 mg / mL, and specific concentrations include but are not limited to: 4 mg / mL, 6 mg / mL and 8 mg / mL; preferably 8 mg / mL.

[0014] Preferably, the mass ratio of the potassium persulfate microcapsules to the sodium chloride microcapsules is 9:1-6:4; the specific mass ratio includes but is not limited to: 9:1, 8:2, 7:3 and 6:4, preferably 7:3.

[0015] The wall material solution is sprayed onto the core material in batches for multiple times and then ground to achieve coating of the core material. Specifically, the wall material solution is sprayed onto the core material 10-20 times. The specific number of spraying times includes but is not limited to: 10 times, 12 times, 15 times, 20 times; preferably 15 times.

[0016] The present invention also provides a method for preparing any of the composite slow-release disinfectants, comprising the following steps:

[0017] (1) dissolving the wall material in anhydrous ethanol to obtain an ethanol solution of the wall material;

[0018] (2) Pour potassium persulfate and sodium chloride and a portion of the ethanol solution of the wall material into a high-speed grinder for grinding;

[0019] (3) adding part of the ethanol solution of the wall material and continuing grinding;

[0020] (4) repeating step (3) until potassium persulfate and sodium chloride are completely coated by the wall material to obtain potassium persulfate microcapsules and sodium chloride microcapsules;

[0021] (5) The potassium persulfate microcapsules and the sodium chloride microcapsules are dried, ground, and then fully mixed to obtain a composite sustained-release disinfectant.

[0022] Furthermore, in steps (2)-(4), the grinding speed is 20000-30000 rpm, and the grinding time is 20-60 s.

[0023] Furthermore, in steps (2)-(4), the ethanol solution of ethyl cellulose is added in 10-20 portions and ground to achieve complete coating of potassium persulfate and sodium chloride.

[0024] In the present invention, the ethanol solution of the wall material ethyl cellulose is added in batches to grind and coat the potassium persulfate or sodium chloride, that is, the wall material is brought into contact with the core material by spraying a small amount and multiple times, and high-speed grinding and stirring are performed at the same time. On the one hand, it is beneficial to reduce the particle size of the core material, and on the other hand, the high-speed rotating grinding knife is beneficial to the uniform mixing of the wall material and the core material.

[0025] Furthermore, in step (4), the drying is performed by vacuum drying, the drying temperature is 50-100° C., and the drying time is 30-90 min.

[0026] The present invention also provides the use of any of the above-mentioned composite slow-release disinfectants or the composite slow-release disinfectants prepared by any of the above-mentioned preparation methods in water disinfection.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] (1) The present invention forms microcapsules of potassium persulfate and sodium chloride respectively and then compounds them, so that the composite sustained-release disinfectant has good stability and sustained-release properties. At the same time, an ethanol solution of the wall material is used to prevent potassium persulfate from contacting with water and being unable to be stably stored, thereby affecting the sustained-release effect. At the same time, the concentration of the ethanol solution of the wall material is optimized to further improve its sustained-release performance.

[0029] (2) The present invention further brings the wall material into contact with the core material by spraying in small amounts and multiple times, while simultaneously performing high-speed grinding and stirring. On the one hand, this is conducive to reducing the particle size of the core material; on the other hand, the high-speed rotating grinding knife is conducive to uniform mixing of the wall material and the core material, which can achieve better coating and thus achieve a better sustained-release effect.

[0030] (3) The present invention further optimizes the mass ratio of potassium persulfate microcapsules and sodium chloride microcapsules in the composite sustained-release disinfectant, thereby achieving a further improvement in the sustained-release effect.

[0031] (4) Finally, the process of the present invention is simple, and the wall material solution can be added in batches according to the amount of the core material to achieve coating. The process is easy to control, does not cause the loss of the wall material, and can achieve complete conversion of the wall material. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 The macroscopic morphology of PMPS microcapsules (A) of Example 2 and NaCl microcapsules (B) of Example 5;

[0033] Figure 2 The microscopic morphology of PMPS microcapsules (A) of Example 2 and NaCl microcapsules (B) of Example 5;

[0034] Figure 3 The infrared spectra of PMPS microcapsules, PMPS and EC;

[0035] Figure 4 The infrared spectra of NaCl microcapsules, NaCl and EC;

[0036] Figure 5 : pH change curves of PMPS microcapsules (Examples 1-3) at different wall material solution concentrations;

[0037] Figure 6 The conductivity change curve of NaCl microcapsules under different spraying times;

[0038] Figure 7 This is the pH change curve of the composite slow-release disinfectant composed of different ratios of PMPS and NaCl. DETAILED DESCRIPTION

[0039] The embodiments of the present invention will be described in detail below in conjunction with examples, but those skilled in the art will appreciate that the following examples are only used to illustrate the present invention and should not be considered to limit the scope of the present invention. It is worth noting that, in the examples, those without specifying specific conditions are carried out according to conventional conditions in the art. Those without specifying the manufacturer of reagents or instruments used are all conventional products that can be purchased commercially.

[0040] Example 1

[0041] Preparation of potassium persulfate microcapsules:

[0042] (1) Weigh 15 g of potassium persulfate and add anhydrous ethanol to prepare a certain amount of 4 mg / mL ethyl cellulose ethanol solution;

[0043] (2) Pour potassium persulfate and 20 mL of ethyl cellulose in an ethanol solution into a high-speed grinder and grind at a speed of 25,000 r / min for 30 seconds;

[0044] (3) Stop grinding, continue to spray 20 mL of ethyl cellulose ethanol solution into the above mixture, and grind again for 30 seconds at a speed of 25000 r / min;

[0045] (4) Repeat the above steps 15 times;

[0046] (5) The mixture was poured out and filtered, and dried under vacuum at 60° C. for 1 hour. The dried solid was ground again to obtain potassium persulfate microcapsules (PMPS microcapsules).

[0047] Example 2

[0048] Preparation of potassium persulfate microcapsules:

[0049] (1) Weigh 15 g of potassium persulfate and add anhydrous ethanol to prepare a certain amount of 6 mg / mL ethyl cellulose ethanol solution;

[0050] (2) Pour potassium persulfate and 20 mL of ethyl cellulose in an ethanol solution into a high-speed grinder and grind at a speed of 25,000 r / min for 30 seconds;

[0051] (3) Stop grinding, spray 20 mL of ethyl cellulose ethanol solution into the mixture, and grind again at a speed of 25000 r / min for 30 s;

[0052] (4) Repeat the above steps 15 times;

[0053] (5) The mixture was poured out and filtered, and dried under vacuum at 60° C. for 1 hour. The dried solid was ground again to obtain potassium persulfate microcapsules (PMPS microcapsules).

[0054] Example 3

[0055] Preparation of Potassium Persulfate Microcapsules

[0056] (1) Weigh 15 g of potassium persulfate and add anhydrous ethanol to prepare a certain amount of 8 mg / mL ethyl cellulose ethanol solution;

[0057] (2) Pour potassium persulfate and 20 mL of ethyl cellulose in an ethanol solution into a high-speed grinder and grind at a speed of 25,000 r / min for 30 seconds;

[0058] (3) Stop grinding, spray 20 mL of ethyl cellulose ethanol solution into the mixture, and grind again at a speed of 25000 r / min for 30 s;

[0059] (4) Repeat the above steps 15 times;

[0060] (5) The mixture was poured out and filtered, and dried under vacuum at 60° C. for 1 hour. The dried solid was ground again to obtain potassium persulfate microcapsules (PMPS microcapsules).

[0061] Example 4

[0062] Preparation of sodium chloride microcapsules:

[0063] (1) Weigh 15 g of sodium chloride and add anhydrous ethanol to prepare a certain amount of 6 mg / mL ethyl cellulose ethanol solution;

[0064] (2) Pour the ethanol solution of sodium chloride and 20 mL of ethyl cellulose into a high-speed grinder and grind at a speed of 25000 r / min for 30 s;

[0065] (3) Stop grinding, spray 20 mL of ethyl cellulose ethanol solution into the mixture, and grind again at a speed of 25000 r / min for 30 s;

[0066] (4) Repeat the above steps 10 times;

[0067] (5) The mixture was poured out and filtered, and dried under vacuum at 60° C. for 1 hour. The dried solid was ground again to obtain sodium chloride microcapsules (NaCl microcapsules).

[0068] Example 5

[0069] Preparation of sodium chloride microcapsules:

[0070] (1) Weigh 15 g of sodium chloride and add anhydrous ethanol to prepare a certain amount of 6 mg / mL ethyl cellulose ethanol solution;

[0071] (2) Pour the ethanol solution of sodium chloride and 20 mL of ethyl cellulose into a high-speed grinder and grind at a speed of 25000 r / min for 30 s;

[0072] (3) Stop grinding, spray 20 mL of ethyl cellulose ethanol solution into the mixture, and grind again at a speed of 25000 r / min for 30 s;

[0073] (4) Repeat the above steps 15 times;

[0074] (5) The mixture was poured out and filtered, and dried under vacuum at 60° C. for 1 hour. The dried solid was ground again to obtain sodium chloride microcapsules (NaCl microcapsules).

[0075] Example 6

[0076] Preparation of sodium chloride microcapsules:

[0077] (1) Weigh 15 g of sodium chloride and add anhydrous ethanol to prepare a certain amount of 6 mg / mL ethyl cellulose ethanol solution;

[0078] (2) Pour the ethanol solution of sodium chloride and 20 mL of ethyl cellulose into a high-speed grinder and grind at a speed of 25000 r / min for 30 s;

[0079] (3) Stop grinding, spray 20 mL of ethyl cellulose ethanol solution into the mixture, and grind again at a speed of 25000 r / min for 30 s;

[0080] (4) Repeat the above steps 20 times;

[0081] (5) The mixture was poured out and filtered, and dried under vacuum at 60° C. for 1 hour. The dried solid was ground again to obtain sodium chloride microcapsules (NaCl microcapsules).

[0082] Next, taking the potassium persulfate microcapsules prepared in Example 2 and the sodium chloride microcapsules prepared in Example 5 as examples, the structures and morphologies of the potassium persulfate microcapsules and the sodium chloride microcapsules of the present invention are characterized.

[0083] 1. Determination of microcapsule structure:

[0084] Infrared spectra of PMPS (potassium persulfate), EC (ethyl cellulose) and PMPS microcapsules Figure 3 The infrared spectrum of PMPS shows that 4000-3000cm -1 There is a broad absorption peak in the range of 2100-2260cm -1There are two absorption peaks in the range, corresponding to the stretching vibration of the O=S=O bond in PMPS; located at about 1100-1200cm -1 Corresponds to the stretching vibration of the OS key; located at about 617cm -1 The infrared spectrum of EC shows that 3470 cm -1 The characteristic absorption peak is caused by the stretching vibration of -OH; 2800-3000cm -1 The two peaks in the range are caused by the stretching vibration of -CH2-; 1376cm -1 The CH stretching vibration represents the carbon-hydrogen bond in cellulose; 1111cm -1 The vibration absorption peak of C2H5O- is at 1062cm -1 The CO stretching vibration at 890 cm-1 corresponds to the carbon-oxygen bond in cellulose. -1 In the infrared spectrum of PMPS microcapsules, the characteristic peaks of EC such as -CH2-, CH, C2H5O-, CO, pyranose ring and glycosidic bond have almost no change, indicating the presence of EC in the microcapsules; at the same time, PMPS has a peak at 2100-2260cm -1 There are two absorption peaks in the range, located at about 617cm -1 Although the stretching vibration of HSO still exists, it becomes very weak, which indicates the existence of PMPS. However, because it is coated by the wall material EC, its absorption peak in the spectrum is weak.

[0085] Infrared spectra of NaCl (sodium chloride), EC (ethyl cellulose) and NaCl microcapsules Figure 4 As shown. Among them, the infrared spectrum of NaCl shows that 4000-3000cm -1 There is a broad absorption peak in the range of 3000-2800cm -1 There is a strong absorption peak in the range of about 1000-1200cm -1 Corresponding to the stretching vibration of the Na-Cl bond; the conservative peak is located at about 605cm -1 , indicating the conserved NaCl structure in the crystal; located at about 400-600 cm -1 Corresponding to the bending vibration of the Na-Cl bond. The infrared spectrum of EC shows that 3470cm -1 The characteristic absorption peak is caused by the stretching vibration of -OH; 2800-3000cm -1 The two peaks in the range are caused by the stretching vibration of -CH2-; 1376cm -1The CH stretching vibration represents the carbon-hydrogen bond in cellulose; 1111cm -1 The vibration absorption peak of C2H5O- is at 1062cm -1 The CO stretching vibration at 890 cm-1 corresponds to the carbon-oxygen bond in cellulose. -1 The infrared spectrum of NaCl microcapsules showed that the characteristic peaks of EC, such as -CH2-, CH, C2H5O-, CO, pyranose ring and glycosidic bond, were almost unchanged, indicating the presence of EC in the microcapsules. -1 The strong absorption peak in the range is located at about 605cm -1 Although the conservative peaks at still exist, they become very weak, which indicates the presence of NaCl. Because the wall material EC is coated with NaCl, its absorption peak in the spectrum is weak.

[0086] In summary, it can be determined through infrared spectroscopy that the preparation method of the present invention realizes the preparation of potassium persulfate microcapsules and sodium chloride microcapsules.

[0087] 2. Morphology Characterization

[0088] The macroscopic morphologies of the PMPS microcapsules prepared in Example 2 and the NaCl microcapsules prepared in Example 5 are shown in FIG. Figure 1 (A) and (B) in the figure are both white granules; the electron microscope images are shown in Figure 2 In (A) and (B), the average particle sizes are around 100um and 200um respectively.

[0089] 3. Analysis of sustained release performance

[0090] (1) The molecular formula of PMPS is 2KHSO5·KHSO4·K2SO4, and the hydrogen sulfate ion HSO 4- The solution will become acidic. By testing the change in pH value of PMPS aqueous solution, the sustained-release performance of PMPS microcapsules can be indirectly evaluated.

[0091] The pH changes of PMPS microcapsules prepared in Examples 1-3 in aqueous solution are as follows: Figure 5 As shown, it can be seen that the pH values ​​of the three samples all show slow nonlinear changes and reach a stable state after a certain period of time, reflecting the sustained release. However, the time to reach the highest point (the strongest acidity) is different. As the concentration of the wall material increases, the time to reach the highest point is successively extended (5 hours, 6.5 hours, 7.5 hours), indicating that within a certain concentration range, the higher the concentration of the wall material, the better the sustained release effect.

[0092] (2) Sodium chloride dissociates in water to produce sodium ions and chloride ions, making the solution conductive. By testing the change in conductivity, the sustained-release performance of sodium chloride microcapsules can be indirectly evaluated.

[0093] The conductivity changes of the NaCl microcapsules prepared in Examples 4-6 in water are as follows: Figure 6 As shown, it can be seen that the release process of NaCl microcapsules can be divided into two parts. The first part is the dissolution of sodium chloride particles remaining on the surface of the microcapsules in water, corresponding to the rapid increase in conductivity near the 0 scale line in the figure. The second part is the slow release of NaCl in the core material of the NaCl microcapsule, corresponding to the part where the conductivity slowly increases in the figure. Analysis shows that the sample sprayed 10 times has the fastest release process in the first part, and the conductivity increases rapidly. Then the second part of the sustained release is carried out, and the conductivity reaches the maximum in about 6 hours and stabilizes after 7 hours; the conductivity of the sample sprayed 15 times also increases slowly, but the growth rate is significantly slower, indicating that the sustained release effect is better, and it will not stabilize until 12 hours later; and the sample sprayed 20 times has better sustained release than the previous two in the first 4 hours, but the release rate increases thereafter, which is greater than the sample sprayed 15 times. The experimental results show that within a certain range, the more times the spraying is applied, the thicker the wall material is, and the better the sustained-release effect is. Therefore, the wall material solution of the present invention is sprayed 10-20 times, preferably 15 times.

[0094] 4. Analysis of the compound ratio of PMPS microcapsules and NaCl microcapsules

[0095] Take PMPS microcapsules (prepared in Example 2) and NaCl microcapsules (prepared in Example 5) and mix them thoroughly according to the ratio in Table 1 to obtain the corresponding composite sustained-release disinfectant, and add them into a beaker filled with 100 mL of deionized water respectively, and control the concentration of the disinfectant to remain unchanged at 10 mg / mL.

[0096] Table 1 PMPS microcapsule and NaCl microcapsule ratio (mass ratio)

[0097]

[0098] The sustained-release properties of the above five composite sustained-release disinfectants were studied, and the results are as follows: Figure 7As shown, it can be seen that the whole process is divided into three stages: the first stage is the straight line segment, which is caused by the rapid dissolution of the disinfectant in water to produce a hydrolysis reaction. The second stage is a chain reaction in the disinfectant system, and the acid strength gradually reaches a peak value. The size of the peak value and the time required to reach the peak value reflect the strength of the disinfectant and the reaction time. In the third stage, the chain reaction gradually reaches a dynamic equilibrium, and the pH of the solution increases and tends to stabilize. The evaluation of the ratio is mainly compared by comparing the acid strength and reaction time achieved in the second stage. Among them, the disinfectant with a mass ratio of PMPS microcapsules to NaCl microcapsules of 7:3 took the longest time to reach the peak in the second stage, about 5 hours, and reached the smallest peak pH (weakly acidic), about 2.5, indicating that this ratio has the best effect; the disinfectants of 9:1, 8:2 and 6:4 are second, and the disinfectant of 5:5 takes the shortest time to reach the peak in the second stage, about 2.5 hours, and reaches the largest peak pH (strongly acidic), about 2.7, and has the worst effect. Therefore, the mass ratio of PMPS microcapsules to NaCl microcapsules in the composite sustained-release disinfectant of the present invention is in the range of 9:1-6:4, preferably 9:1.

[0099] Finally, it should be noted that the above content is only used to illustrate the technical solution of the present invention, rather than to limit the scope of protection of the present invention. Simple modifications or equivalent substitutions of the technical solution of the present invention by ordinary technicians in this field do not deviate from the essence and scope of the technical solution of the present invention.

Claims

1. A potassium persulfate and sodium chloride composite slow-release disinfectant, characterized in that: The composite sustained-release disinfectant consists of potassium persulfate microcapsules and sodium chloride microcapsules; the potassium persulfate microcapsules and sodium chloride microcapsules are prepared by using potassium persulfate and sodium chloride as core materials, respectively, and coating with an ethanol solution of a wall material.

2. The composite slow-release disinfectant according to claim 1, characterized in that: The wall material is selected from one or more of ethyl cellulose, butyl cellulose and rosin.

3. The composite slow-release disinfectant according to claim 1, characterized in that: The mass ratio of potassium persulfate and sodium chloride to the wall material is 4:1-20:

1.

4. The composite slow-release disinfectant according to claim 1, characterized in that: The concentration of the wall material ethanol solution is 4-8 mg / mL.

5. The composite slow-release disinfectant according to claim 1, characterized in that: The wall material solution is sprayed onto the core material in batches for multiple times and then ground to achieve coating of the core material. Specifically, the wall material solution is sprayed onto the core material for 10-20 times.

6. The composite slow-release disinfectant according to claim 1, characterized in that: The mass ratio of the potassium persulfate microcapsules to the sodium chloride microcapsules is 9:1-6:

4.

7. The method for preparing the composite sustained-release disinfectant according to any one of claims 1 to 6, characterized in that: The following steps are involved: (1) dissolving the wall material in anhydrous ethanol to obtain an ethanol solution of the wall material; (2) pouring potassium persulfate and sodium chloride and an ethanol solution of a portion of the wall material into a high-speed grinder for grinding; (3) adding part of the ethanol solution of the wall material and continuing grinding; (4) repeating step (3) until potassium persulfate and sodium chloride are completely coated by the wall material to obtain potassium persulfate microcapsules and sodium chloride microcapsules; (5) The potassium persulfate microcapsules and the sodium chloride microcapsules are dried, ground, and then fully mixed to obtain a composite sustained-release disinfectant.

8. The preparation method according to claim 7, characterized in that: In steps (2)-(4), the grinding speed is 20000-30000 rpm, and the grinding time is 20-60 s.

9. The preparation method according to claim 7, characterized in that: In step (4), vacuum drying is used for drying, the drying temperature is 50-100° C., and the drying time is 30-90 min.

10. Use of the composite sustained-release disinfectant according to any one of claims 1 to 6 or the composite sustained-release disinfectant prepared by the preparation method according to claim 8 or 9 in water disinfection.

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