Solid slow-release scale inhibition material with antibacterial function and preparation method thereof

Abstract

The invention belongs to the technical field of water treatment agents, and particularly relates to a solid slow-release scale inhibition material with an antibacterial function and a preparation method of the solid slow-release scale inhibition material. According to the preparation method of the solid slow-release scale inhibition material with the antibacterial function, provided by the invention, formylated starch without biotoxicity is taken as a cross-linking agent, chitosan quaternary ammonium salt is taken as a cross-linking matrix, the formylated starch and the chitosan quaternary ammonium salt are simultaneously mixed with scale inhibition and bacteriostasis components, and a cross-linking material is prepared through a Schiff base reaction between formyl groups and amino groups; and coating of the scale inhibition and bacteriostasis component by the crosslinking material is synchronously realized. Further, curdlan is adopted to carry out secondary coating on the scale inhibition and bacteriostasis component, so that the solid slow-release scale inhibition material with the antibacterial function is prepared. The preparation method disclosed by the invention is simple in process operation and mild in condition, and through twice coating treatment, the structural stability of the scale inhibition material can be effectively improved, the long-acting antibacterial performance and the scale inhibition slow release effect of the scale inhibition material can be remarkably improved, and the scale inhibition material is suitable for being used in a water treatment environment.

Description

Technical Field

[0001] The invention belongs to the technical field of water treatment agents, and in particular relates to a solid slow-release scale-inhibiting material with antibacterial function and a preparation method thereof. Background Art

[0002] With the rapid economic growth and the strengthening of the concept of health and environmental protection, people's requirements for water quality are increasing day by day. At the same time, water shortage has become one of the important factors restricting economic development. How to further develop advanced water treatment agents and water treatment technologies to improve water treatment efficiency and water resource utilization is of great value to avoid water waste and improve water shortage.

[0003] In the process of domestic water treatment, commercial or industrial circulating cooling water, scaling ions such as Ca 2+ Mg 2+ As well as other hardness components, they are prone to form fixed precipitates that are insoluble in water after long-term accumulation. These substances are deposited on the surface of water system pipes and equipment, which can easily lead to scaling and blockage in the water system, thereby reducing water use efficiency and the service life of equipment, and greatly affecting water safety. At the same time, since the water temperature in the water system is generally between 25 and 45°C, and the water contains nutrients required for microbial growth (such as carbon sources, nitrogen sources, and mineral ions, etc.), it is easy for microorganisms to grow and reproduce in the water body and generate a large amount of biological slime. The growth of microorganisms will not only reduce water safety, but also long-term accumulation will block water pipes, accelerate the corrosion of metal pipes, and even cause damage to water treatment equipment.

[0004] In order to ensure the safe operation of the water system and the safety of water use, strict control of scaling and microbial growth in the water treatment process has become an important part of water treatment. At present, although people can slow down the occurrence of scaling and microbial growth through many ways. However, in order to improve efficiency and save costs, chemical water treatment agents are still recognized as low-cost, highly practical, simple and fast methods. However, most of the existing water treatment agents are single-function preparations, such as scale inhibitors and bactericides with specific effects. When they are applied, they are added separately by each agent to play the role of scale inhibition and inhibition of microbial growth. However, the process of adding multiple agents undoubtedly increases the complexity of the agent application operation, increases the total amount and cost of chemical agents, and reduces the overall safety of the water body. At the same time, the existing single scale inhibitors and bactericides are prone to the problem of too fast failure speed and short action cycle, which has also become the key to restricting the effect of water treatment agents.

[0005] In view of the application defects of the above-mentioned single water treatment agent and the demand for sustainable development, the research and development focus of water treatment agents has gradually shifted towards environmental friendliness and multi-functionality in recent years. Therefore, how to develop an environmentally friendly scale-inhibiting material with integrated scale inhibition, antibacterial and long-term slow-release functions to comprehensively solve the problems of scaling, microbial contamination and short action cycle is of great significance for improving water use efficiency and water safety. Summary of the invention

[0006] In order to overcome the deficiencies in the prior art, the object of the present invention is to provide a solid slow-release antiscaling material with antibacterial function and a preparation method thereof.

[0007] To achieve the above object, the technical solution adopted by the present invention is: A method for preparing a solid slow-release scale-inhibiting material with antibacterial function comprises the following steps: (1) Oxidizing starch with sodium periodate to obtain aldehyde-modified starch; (2) uniformly mixing the aldehyde starch, chitosan quaternary ammonium salt and the anti-scaling and antibacterial component in water to obtain a mixed solution; adjusting the pH of the mixed solution to 8-9, carrying out a cross-linking reaction at 40-60° C. under stirring conditions; after the reaction is completed, filtering, washing, drying, and then granulating the obtained product to obtain solid particles; (3) The solid particles obtained in step (2) are placed in a curdlan dispersion for vacuum impregnation treatment, and then dried to obtain a solid slow-release antiscaling material with antibacterial function.

[0008] Preferably, in step (1), the oxidation treatment process is: stirring and dissolving starch and sodium periodate in an acetic acid solution, and then stirring and reacting at 30-40° C. in a dark environment for 6-10 hours, and then dialyzing and freeze-drying the resulting solution to obtain aldehyde-modified starch.

[0009] Further preferably, the mass ratio of the starch to sodium periodate is (1-2):1; and the mass concentration of acetic acid in the acetic acid solution is 1%-2%.

[0010] Preferably, in step (2), the mass ratio of the aldehyde starch, chitosan quaternary ammonium salt, antiscaling and antibacterial component, and water is (0.4-0.8): (2.3-2.5): (1.4-1.6): (55-65).

[0011] Preferably, in step (2), the anti-scaling and anti-bacterial component comprises the following raw materials in parts by weight: 2.2-2.6 parts of polyepoxysuccinic acid, 1.4-1.8 parts of sodium lignin sulfonate, and 0.4-0.6 parts of paeonol; Preferably, in step (2), the cross-linking reaction time is 2-4 hours; and the stirring speed is 80-120 r / min.

[0012] Preferably, in step (2), the granulation is dry granulation; and the particle size of the solid particles is 10-30 mesh.

[0013] Preferably, in step (3), the mass concentration of curdlan in the curdlan dispersion is 4% to 8%.

[0014] Preferably, in step (3), the vacuum degree of the vacuum impregnation is -0.05 to -0.095 MPa, and the vacuum impregnation time is 20 to 40 min.

[0015] A solid slow-release scale-inhibiting material with antibacterial function prepared by the preparation method.

[0016] The technical solution of the present invention has the following advantages and beneficial effects: The method for preparing a solid slow-release anti-bacterial material with anti-bacterial function provided by the present invention uses non-biotoxic aldehyde-formyl starch as a cross-linking agent, uses chitosan quaternary ammonium salt as a cross-linking matrix, and mixes with anti-bacterial components at the same time, prepares a cross-linking material through a Schiff base reaction between an aldehyde group and an amino group, and simultaneously realizes coating of the anti-bacterial components with the cross-linking material. Furthermore, the present invention uses curdlan to perform secondary coating of the anti-bacterial components to prepare a solid slow-release anti-bacterial material with anti-bacterial function.

[0017] The above-mentioned preparation method of the present invention has simple process operation and mild conditions, and through two coating treatments, it can effectively improve the structural stability of the scale-inhibiting material, significantly improve the long-term antibacterial performance and scale-inhibiting slow-release effect of the scale-inhibiting material, and is suitable for use in water treatment environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a graph showing the variation of the scale inhibition rate over time after the scale inhibition materials provided in Example 1 and Comparative Examples 1 to 4 of the present invention are used for water treatment. DETAILED DESCRIPTION

[0019] The following is an explanation of the present invention by way of example, but the present invention is not limited to the following embodiments. For ordinary technicians in the technical field to which the present invention belongs, without departing from the concept of the present invention, several simple deductions or substitutions can be made, which should be regarded as belonging to the protection scope of the present invention. Among them, in the following embodiments, starch is soluble starch, the degree of substitution of chitosan quaternary ammonium salt is 95%, the purity of paeonol is greater than 99%, and the deacetylation degree of chitosan is ≥95%, which comes from Shanghai McLean. The purity of curdlan and carrageenan is greater than 98%; the mass content of polyepoxysuccinic acid is 50%; the model of sodium lignin sulfonate is TY-8912, which is a conventional commercial product. Other raw materials, unless otherwise specified, are conventional materials that can be obtained through commercial channels.

[0020] Example 1 This embodiment provides a solid slow-release antiscaling material with antibacterial function, and its preparation method comprises the following steps: (1) 6 g starch and 4 g sodium periodate were placed in 80 mL acetic acid solution and stirred to dissolve, then stirred and reacted for 8 h at 35 °C in the dark, and the solution after the reaction was dialyzed in a dialysis bag for 48 h (molecular weight cutoff 7000 Da, water was changed every 8 h) to remove excess oxidant, and then freeze-dried to obtain aldehyde-modified starch. The mass concentration of acetic acid in the acetic acid solution was 1.5%.

[0021] (2) By weight, 0.6 parts of formaldehyde starch, 2.4 parts of chitosan quaternary ammonium salt, and 1.5 parts of anti-scaling and antibacterial components were uniformly mixed in 60 parts of deionized water to obtain a mixed solution; wherein the anti-scaling and antibacterial components consisted of polyepoxysuccinic acid, sodium lignin sulfonate, and paeonol, and the mass ratio of the three was 2.4:1.6:0.5; then the pH of the mixed solution was adjusted to 8-9, and a cross-linking reaction was carried out at 50°C and 100 r / min for 3 h. After the reaction, the obtained product was filtered, washed with water, dried, and then dry granulated to obtain solid particles with a particle size of 10-30 mesh.

[0022] (3) The solid particles obtained in step (2) are placed in a curdlan dispersion having a mass concentration of 5%, and vacuum impregnated at -0.08 MPa for 30 min, and then taken out and dried to obtain a solid slow-release antiscaling material with antibacterial function. The curdlan dispersion is prepared by ultrasonically dispersing the curdlan in deionized water at 40°C for 2 h.

[0023] Example 2 This embodiment provides a solid slow-release antiscaling material with antibacterial function, and its preparation method comprises the following steps: (1) 5 g of starch and 5 g of sodium periodate were placed in 80 mL of acetic acid solution and stirred to dissolve, then stirred and reacted for 8 h at 35 °C in the dark, and the solution after the reaction was dialyzed in a dialysis bag for 48 h (molecular weight cutoff 7000 Da, water was changed every 8 h) to remove excess oxidant, and then freeze-dried to obtain aldehyde-modified starch. The mass concentration of acetic acid in the acetic acid solution was 1.5%.

[0024] (2) By weight, 0.8 parts of formaldehyde starch, 2.5 parts of chitosan quaternary ammonium salt, and 1.5 parts of anti-scaling and antibacterial components were uniformly mixed in 60 parts of deionized water to obtain a mixed solution; wherein the anti-scaling and antibacterial components consisted of polyepoxysuccinic acid, sodium lignin sulfonate, and paeonol, and the mass ratio of the three was 2.4:1.6:0.5; then the pH of the mixed solution was adjusted to 8-9, and a cross-linking reaction was carried out at 50°C and 100 r / min for 3 h. After the reaction, the obtained product was filtered, washed with water, dried, and then dry granulated to obtain solid particles with a particle size of 10-30 mesh.

[0025] (3) The solid particles obtained in step (2) are placed in a curdlan dispersion having a mass concentration of 8%, and vacuum impregnated at -0.08 MPa for 30 min, and then taken out and dried to obtain a solid slow-release antiscaling material with antibacterial function. The curdlan dispersion is prepared by ultrasonically dispersing the curdlan in deionized water at 40°C for 2 h.

[0026] Example 3 This embodiment provides a solid slow-release antiscaling material with antibacterial function, and its preparation method comprises the following steps: (1) 6 g starch and 3 g sodium periodate were placed in 80 mL acetic acid solution and stirred to dissolve, then stirred and reacted for 8 h at 35 °C in the dark, and the solution after the reaction was dialyzed in a dialysis bag for 48 h (molecular weight cutoff 7000 Da, water was changed every 8 h) to remove excess oxidant, and then freeze-dried to obtain aldehyde starch. The mass concentration of acetic acid in the acetic acid solution was 1.5%.

[0027] (2) By weight, 0.4 parts of formaldehyde starch, 2.3 parts of chitosan quaternary ammonium salt, and 1.5 parts of anti-scaling and antibacterial components were uniformly mixed in 60 parts of deionized water to obtain a mixed solution; wherein the anti-scaling and antibacterial components consisted of polyepoxysuccinic acid, sodium lignin sulfonate, and paeonol, and the mass ratio of the three was 2.4:1.6:0.5; then the pH of the mixed solution was adjusted to 8-9, and a cross-linking reaction was carried out at 50°C and 100 r / min for 3 hours. After the reaction, the obtained product was filtered, washed with water, dried, and then dry granulated to obtain solid particles with a particle size of 10-30 mesh.

[0028] (3) The solid particles obtained in step (2) are placed in a 4% by mass concentration curdlan dispersion, and vacuum impregnated at -0.08 MPa for 30 minutes, and then taken out and dried to obtain a solid slow-release antiscaling material with antibacterial function. The curdlan dispersion is prepared by ultrasonically dispersing the curdlan in deionized water at 40°C for 2 hours.

[0029] Example 4 This embodiment provides a solid slow-release antiscaling material with antibacterial function, and its preparation method comprises the following steps: (1) 6 g starch and 4 g sodium periodate were placed in 80 mL acetic acid solution and stirred to dissolve, then stirred and reacted for 8 h at 35 °C in the dark, and the solution after the reaction was dialyzed in a dialysis bag for 48 h (molecular weight cutoff 7000 Da, water was changed every 8 h) to remove excess oxidant, and then freeze-dried to obtain aldehyde-modified starch. The mass concentration of acetic acid in the acetic acid solution was 1.5%.

[0030] (2) By weight, 0.5 parts of formaldehyde starch, 2.5 parts of chitosan quaternary ammonium salt, and 1.6 parts of anti-scaling and antibacterial components were uniformly mixed in 60 parts of deionized water to obtain a mixed solution; wherein the anti-scaling and antibacterial components consisted of polyepoxysuccinic acid, sodium lignin sulfonate, and paeonol, and the mass ratio of the three was 2.6:1.4:0.5; then the pH of the mixed solution was adjusted to 8-9, and a cross-linking reaction was carried out at 50°C and 100 r / min for 3 hours. After the reaction was completed, the obtained product was filtered, washed with water, dried, and then dry granulated to obtain solid particles with a particle size of 10-30 mesh.

[0031] (3) The solid particles obtained in step (2) are placed in a curdlan dispersion having a mass concentration of 8%, and vacuum impregnated at -0.08 MPa for 30 min, and then taken out and dried to obtain a solid slow-release antiscaling material with antibacterial function. The curdlan dispersion is prepared by ultrasonically dispersing the curdlan in deionized water at 40°C for 2 h.

[0032] Comparative Example 1 This comparative example provides a scale inhibition material, and its preparation method is basically the same as that of Example 1, except that in step (2), an equal mass of chitosan is used to replace chitosan quaternary ammonium salt, and the remaining steps are the same as those of Example 1.

[0033] Comparative Example 2 This comparative example provides a scale inhibition material, and the preparation method thereof comprises the following steps: (1) By weight, 0.6 parts of starch, 2.4 parts of chitosan quaternary ammonium salt, and 1.5 parts of anti-scaling and anti-bacterial components were mixed evenly in 60 parts of deionized water to obtain a mixed solution; wherein the anti-scaling and anti-bacterial components consisted of polyepoxysuccinic acid, sodium lignin sulfonate, and paeonol, and the mass ratio of the three was 2.4:1.6:0.5. The mixed solution was dried and then dry granulated to obtain solid particles with a particle size of 10-30 mesh.

[0034] (2) The solid particles obtained in step (1) are placed in a 6% by mass concentration curdlan dispersion, and vacuum impregnated at -0.08 MPa for 30 minutes, and then taken out and dried to obtain a solid slow-release anti-scaling material with antibacterial function. The curdlan dispersion is prepared by ultrasonically dispersing the curdlan in deionized water at 40°C for 2 hours.

[0035] Comparative Example 3 This comparative example provides a scale inhibition material, and its preparation method is basically the same as that of Example 1, except that step (3) is omitted, and the remaining steps are the same as those of Example 1.

[0036] Comparative Example 4 This comparative example provides a scale inhibitor material, and its preparation method is basically the same as that of Example 1, except that in step (3), an equal amount of carrageenan is used instead of curdlan, and the remaining steps are the same as those of Example 1.

[0037] Test Example 1: Antibacterial Performance Test This experiment tests the antibacterial performance of antiscaling materials to evaluate the antibacterial effect of different antiscaling materials. The heterotrophic bacteria used in the experiment were enriched from the on-site circulating water. After the heterotrophic bacteria were enriched, they were resuspended in PBS to obtain an effective bacterial concentration of 1×10 6 CFU / mL heterotrophic bacterial suspension. The composition of the heterotrophic bacterial culture medium is: 15g agar, 10g peptone, 3g beef extract, 3g sodium chloride, distilled water to 1L, pH adjusted to 7.0, and sterilized for use.

[0038] (1) Comparison of the antibacterial effect of antiscaling materials at different concentrations: 200 mL of circulating cooling water sample and 1 mL of heterotrophic bacterial suspension (1×10 6 CFU / mL) were mixed, and then the scale inhibitor materials of Example 1 (10, 20, 40, 80 mg / L) were added respectively, and a control group without scale inhibitor was set up at the same time. The samples obtained after adding the scale inhibitor were cultured in a biochemical incubator at 37±1°C, and samples were taken on the 1st, 10th, 20th and 30th day of culture, respectively, and inoculated into heterotrophic bacteria culture medium, the number of heterotrophic bacteria was determined, and the inhibition rate was calculated. The results were taken as the average of three tests. The results are shown in Table 1.

[0039] Table 1. Comparison of antibacterial effects of scale inhibitors of Example 1 at different concentrations As shown in Table 1, when the concentration of the scale inhibitor is less than 40 mg / L, the antibacterial rate is low; when the concentration of the scale inhibitor is greater than 40 mg / L, it can effectively inhibit the growth of heterotrophic bacteria and achieve excellent antibacterial effect. However, when the concentration of the scale inhibitor increases to 80 mg / L, the increase in the antibacterial effect is not large compared to that at 40 mg / L. Therefore, from the perspective of controlling the cost of water treatment agents, the dosage of the scale inhibitor is set at 40 mg / L.

[0040] (2) Comparison of the antibacterial effects of different antiscaling materials at the same concentration: 200 mL of circulating cooling water sample and 1 mL of heterotrophic bacterial suspension (1×10 6 CFU / mL) were mixed, and the scale inhibitors of Examples 1 to 4 and Comparative Examples 1 to 4 (concentration 40 mg / L) were added respectively, and a control group without scale inhibitor was set up. The samples obtained after adding the scale inhibitor were cultured in a biochemical incubator at 37±1°C, and samples were taken on the 1st, 10th, 20th, 30th and 60th days of culture, respectively, and inoculated into heterotrophic bacteria culture medium, the number of heterotrophic bacteria was determined, and the inhibition rate was calculated. The results were taken as the average of three tests. The results are shown in Table 2.

[0041] Table 2. Comparison of antibacterial effects of scale inhibitors of Examples 1 to 4 and Comparative Examples 1 to 4 It can be seen from the results in Table 2 that the antibacterial effect of the scale-inhibiting materials of Examples 1 to 4 of the present invention is relatively excellent within 1 to 10 days, the antibacterial effect decreases after 20 days, and the antibacterial effect decreases more significantly after 30 days. However, the antibacterial rate of the scale-inhibiting materials of Examples 1 to 4 can still reach more than 80% after 30 days of action, and the antibacterial rate can still reach more than 72% after 60 days of action, meeting the long-term antibacterial requirements. Through a comprehensive comparison of the embodiments and the comparative examples, it can be seen that although the antibacterial effect of the scale-inhibiting materials of Comparative Examples 1 to 4 is relatively good within 1 to 10 days and can meet the antibacterial requirements, after 10 days, the antibacterial rate of the scale-inhibiting materials of Comparative Examples 1 to 4 decreases significantly. This shows that the scale-inhibiting material of the present invention has an effective inhibitory effect on bacterial growth and can play a more long-term role in reducing bacterial reproduction, that is, it has an excellent long-term antibacterial effect.

[0042] Test Example 2: Scale Inhibition Performance Test In this experiment, the scale inhibition performance of the scale inhibition materials prepared in Example 1 and Comparative Examples 1 to 4 was tested. The scale inhibition performance was determined as follows: 1 g of the scale inhibition material sample was weighed, packed in different gauze bags, and then placed in a 1 L simulated water environment (containing 300 mg / L Ca 2+, 200 mg / L HCO ﹣ ), the temperature was kept at 60±1℃ for static scale inhibition test, each scale inhibition material was slowly released into the water body, 20mL of supernatant was taken after 1 day, and the scale inhibition rate was measured. After sampling, the gauze bag was taken out and put back into the newly configured 1000mL simulated water environment, and the scale inhibition test was carried out in this cycle. Samples were taken and tested on the 1st, 10th, 20th, 40th and 60th days, and the scale inhibition rate was measured. The scale inhibition rate change curve was drawn. The results are shown as follows Figure 1 shown.

[0043] like Figure 1 As shown, the scale inhibition rate of the scale inhibition material provided in Example 1 of the present invention reaches 74.5% after a 60-day test period. However, the scale inhibition rate of the scale inhibition materials provided in Comparative Examples 1 to 4 decreases significantly. It can be seen that the scale inhibition effect of the scale inhibition material provided by the present invention is excellent, and the sustained release period is long.

[0044] In summary, the preparation method of the solid slow-release antiscaling material with antibacterial function provided by the present invention can effectively improve the structural stability of the antiscaling material through two coating treatments, significantly improve the long-term antibacterial performance and slow-release effect of the antiscaling material, and is suitable for use in water treatment environments.

Claims

1. A method for preparing a solid slow-release scale-inhibiting material with antibacterial function, characterized in that: The following steps are involved: (1) Oxidizing starch with sodium periodate to obtain aldehyde-modified starch; (2) uniformly mixing the aldehyde starch, chitosan quaternary ammonium salt and the anti-scaling and antibacterial component in water to obtain a mixed solution; adjusting the pH of the mixed solution to 8-9, carrying out a cross-linking reaction at 40-60° C. under stirring conditions; after the reaction is completed, filtering, washing, drying, and then granulating the obtained product to obtain solid particles; (3) The solid particles obtained in step (2) are placed in a curdlan dispersion for vacuum impregnation treatment, and then dried to obtain a solid slow-release antiscaling material with antibacterial function.

2. The method for preparing a solid slow-release antiscaling material with antibacterial function according to claim 1, characterized in that: In step (1), the oxidation treatment process is as follows: starch and sodium periodate are stirred and dissolved in an acetic acid solution, and then stirred and reacted for 6 to 10 hours at 30 to 40° C. and in the dark, and then the resulting solution is dialyzed and freeze-dried to obtain aldehyde-modified starch.

3. The method for preparing a solid slow-release antiscaling material with antibacterial function according to claim 2, characterized in that: The mass ratio of the starch to sodium periodate is (1-2):1; the mass concentration of acetic acid in the acetic acid solution is 1%-2%.

4. The method for preparing a solid slow-release antiscaling material with antibacterial function according to claim 1, characterized in that: In step (2), the mass ratio of the aldehyde starch, chitosan quaternary ammonium salt, antiscaling and antibacterial component, and water is (0.4-0.8): (2.3-2.5): (1.4-1.6): (55-65).

5. The method for preparing a solid slow-release antiscaling material with antibacterial function according to claim 1, characterized in that: In step (2), the anti-scaling and antibacterial component comprises the following raw materials in parts by weight: 2.2-2.6 parts of polyepoxysuccinic acid, 1.4-1.8 parts of sodium lignin sulfonate, and 0.4-0.6 parts of paeonol.

6. The method for preparing a solid slow-release antiscaling material with antibacterial function according to claim 1, characterized in that: In step (2), the cross-linking reaction time is 2-4 hours; the stirring speed is 80-120 r / min.

7. The method for preparing a solid slow-release antiscaling material with antibacterial function according to claim 1, characterized in that: In step (2), the granulation is dry granulation; the particle size of the solid particles is 10-30 mesh.

8. The method for preparing the solid slow-release scale-inhibiting material with antibacterial function according to any one of claims 1 to 7, characterized in that: In step (3), the mass concentration of curdlan in the curdlan dispersion is 4% to 8%.

9. The method for preparing the solid slow-release scale-inhibiting material with antibacterial function according to any one of claims 1 to 7, characterized in that: In step (3), the vacuum degree of the vacuum impregnation is -0.05~-0.095MPa, and the vacuum impregnation time is 20~40min.

10. A solid slow-release scale-inhibiting material with antibacterial function prepared by the preparation method according to any one of claims 1 to 9.

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