A solid slow-release scale-inhibiting material with antibacterial function and its preparation method

Abstract

The present invention belongs to the technical field of water treatment agents, and specifically, relates to a solid slow-release scale inhibitor material with antibacterial function and a preparation method thereof. The preparation method of the solid slow-release scale inhibitor material with antibacterial function provided by the present invention uses non-biotoxic aldehyde-modified starch as a cross-linking agent and chitosan quaternary ammonium salt as a cross-linking matrix, and is mixed with scale inhibitory and antibacterial components at the same time, and a Schiff base reaction between the aldehyde group and the amino group is used to prepare a cross-linked material, and the cross-linked material is simultaneously coated on the scale inhibitory and antibacterial components. Furthermore, the present invention uses curdlan to coat the scale inhibitory and antibacterial components for a second time to prepare a solid slow-release scale inhibitor material with antibacterial function. 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 inhibitor material, significantly improve the long-term antibacterial performance and scale inhibition slow-release effect of the scale inhibitor material, and is suitable for use in water treatment environments.

Description

Technical Field

[0001] The present 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 rapid economic growth and a growing awareness of health and environmental protection, people's demands for water quality are increasing. At the same time, water shortage has become a major factor restricting economic development. The development of advanced water treatment agents and technologies to improve water treatment efficiency and water resource utilization is crucial for avoiding water waste and alleviating water shortages.

[0003] In the process of domestic water treatment, commercial or industrial circulating cooling water, scaling ions such as Ca 2+ Mg 2+ Along with other hardness components, these substances easily form insoluble, fixed precipitates over time. These substances deposit on the surfaces of water system pipes and equipment, easily leading to scaling and clogging of the water system, reducing water efficiency and equipment lifespan, and significantly impacting water safety. Furthermore, because the water temperature in water systems generally ranges from 25°C to 45°C and contains nutrients necessary for microbial growth (such as carbon and nitrogen sources, and mineral ions), these substances can easily allow microorganisms to grow and reproduce within the water, generating large amounts of biosludge. Microbial growth not only reduces water safety, but long-term accumulation can also clog water lines, accelerate corrosion of metal pipes, and even damage water treatment equipment.

[0004] In order to ensure the safe operation of the water system and guarantee the safety of water use, strict control of scaling and microbial growth during 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 means. 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 adding each agent to play the role of scale inhibition and microbial growth inhibition. 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 rapid failure and short action period, which has become the key to restricting the effect of water treatment agents.

[0005] Given the aforementioned limitations of single-agent water treatment applications and the need for sustainable development, the research and development of water treatment agents has shifted in recent years toward environmentally friendly, multifunctional solutions. Therefore, developing an environmentally friendly scale inhibitor that combines scale inhibition, antibacterial properties, and long-lasting sustained-release properties to comprehensively address scaling, microbial contamination, and short lifespans is crucial for improving water efficiency and safety. Summary of the Invention

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

[0007] To achieve the above object, the technical solution adopted by the present invention is:

[0008] A method for preparing a solid slow-release scale-inhibiting material with antibacterial function comprises the following steps:

[0009] (1) Starch is oxidized with sodium periodate to obtain aldehyde-modified starch;

[0010] (2) The aldehyde-modified starch, chitosan quaternary ammonium salt and anti-scaling and antibacterial components are uniformly mixed in water to obtain a mixed solution; the pH of the mixed solution is adjusted to 8-9, and a cross-linking reaction is carried out at 40-60°C under stirring conditions. After the reaction is completed, the obtained product is filtered, washed with water, dried, and then granulated to obtain solid particles;

[0011] (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 scale-inhibiting material with antibacterial function.

[0012] Preferably, 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 at 30-40° C. in the dark for 6-10 hours, and then the resulting solution is dialyzed and freeze-dried to obtain aldehyded starch.

[0013] 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%.

[0014] Preferably, in step (2), the mass ratio of the formaldehyde starch, chitosan quaternary ammonium salt, scale inhibition and antibacterial component, and water is (0.4-0.8): (2.3-2.5): (1.4-1.6): (55-65).

[0015] Preferably, in step (2), the scale inhibition 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;

[0016] Preferably, in step (2), the cross-linking reaction time is 2 to 4 hours; and the stirring speed is 80 to 120 r / min.

[0017] Preferably, in step (2), the granulation is dry granulation; and the particle size of the solid particles is 10-30 mesh.

[0018] Preferably, in step (3), the mass concentration of the curdlan in the curdlan dispersion is 4% to 8%.

[0019] 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 minutes.

[0020] A solid slow-release scale-inhibiting material with antibacterial function prepared by the above preparation method.

[0021] The technical solution of the present invention has the following advantages and beneficial effects:

[0022] The present invention provides a method for preparing a solid, slow-release, antibacterial scale-inhibiting material. The method uses non-biotoxic aldehyde-modified starch as a crosslinking agent and chitosan quaternary ammonium salt as a crosslinking matrix. These are mixed with a scale-inhibiting and antibacterial component. A Schiff base reaction between aldehyde groups and amino groups is performed to prepare the crosslinked material. The crosslinked material then coats the scale-inhibiting and antibacterial component. Furthermore, the present invention uses curdlan to perform a secondary coating on the scale-inhibiting and antibacterial component to produce the solid, slow-release, antibacterial scale-inhibiting material.

[0023] The above-mentioned preparation method of the present invention has simple process operation and mild conditions. Through two coating treatments, it can effectively improve the structural stability of the scale inhibition material, significantly improve the long-term antibacterial performance and scale inhibition slow-release effect of the scale inhibition material, and is suitable for use in water treatment environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a graph showing the change in 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

[0025] The following is an illustration of the present invention by way of examples, but the present invention is not limited to the following examples. 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 replacements can be made, which should be regarded as belonging to the scope of protection 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.

[0026] Example 1

[0027] This embodiment provides a solid slow-release scale-inhibiting material with antibacterial function, the preparation method of which comprises the following steps:

[0028] (1) 6 g of starch and 4 g of sodium periodate were dissolved in 80 mL of acetic acid solution with stirring. The mixture was then stirred at 35°C in the dark for 8 h. The resulting solution was dialyzed in a dialysis bag for 48 h (molecular weight cut-off 7000 Da, with water changed every 8 h) to remove excess oxidant. The solution was then freeze-dried to obtain aldehyde-modified starch. The mass concentration of acetic acid in the acetic acid solution was 1.5%.

[0029] (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 mixed evenly 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.

[0030] (3) The solid particles obtained in step (2) are placed in a 5% by mass concentration of curdlan dispersion, and vacuum impregnated at -0.08 MPa for 30 minutes, and then removed and dried to obtain a solid slow-release scale inhibitor with antibacterial function. The curdlan dispersion is prepared by ultrasonically dispersing the curdlan in deionized water at 40°C for 2 hours.

[0031] Example 2

[0032] This embodiment provides a solid slow-release scale-inhibiting material with antibacterial function, the preparation method of which comprises the following steps:

[0033] (1) 5 g of starch and 5 g of sodium periodate were placed in 80 mL of acetic acid solution and stirred to dissolve. The mixture was then stirred at 35°C in the dark for 8 h. The resulting solution was dialyzed in a dialysis bag for 48 h (molecular weight cut-off 7000 Da, with water changed every 8 h) to remove excess oxidant. The solution was then freeze-dried to obtain aldehyde-modified starch. The mass concentration of acetic acid in the acetic acid solution was 1.5%.

[0034] (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 mixed evenly 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.

[0035] (3) The solid particles obtained in step (2) are placed in a curdlan dispersion having a mass concentration of 8%, and subjected to vacuum impregnation treatment at -0.08 MPa for 30 minutes, followed by removal and drying to obtain a solid slow-release scale inhibitor having antibacterial function. The curdlan dispersion is prepared by ultrasonically dispersing the curdlan in deionized water at 40°C for 2 hours.

[0036] Example 3

[0037] This embodiment provides a solid slow-release scale-inhibiting material with antibacterial function, the preparation method of which comprises the following steps:

[0038] (1) 6 g of starch and 3 g of sodium periodate were placed in 80 mL of acetic acid solution and stirred to dissolve. The mixture was then stirred at 35°C in the dark for 8 h. The resulting solution was dialyzed in a dialysis bag for 48 h (molecular weight cut-off 7000 Da, with water changed every 8 h) to remove excess oxidant. The solution was then freeze-dried to obtain aldehyde-modified starch. The mass concentration of acetic acid in the acetic acid solution was 1.5%.

[0039] (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 mixed evenly 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.

[0040] (3) The solid particles obtained in step (2) are placed in a 4% by mass curdlan dispersion, and subjected to vacuum impregnation treatment at -0.08 MPa for 30 minutes, followed by drying to obtain a solid slow-release scale inhibitor with antibacterial function. The curdlan dispersion is prepared by ultrasonically dispersing the curdlan in deionized water at 40°C for 2 hours.

[0041] Example 4

[0042] This embodiment provides a solid slow-release scale-inhibiting material with antibacterial function, the preparation method of which comprises the following steps:

[0043] (1) 6 g of starch and 4 g of sodium periodate were dissolved in 80 mL of acetic acid solution with stirring. The mixture was then stirred at 35°C in the dark for 8 h. The resulting solution was dialyzed in a dialysis bag for 48 h (molecular weight cut-off 7000 Da, with water changed every 8 h) to remove excess oxidant. The solution was then freeze-dried to obtain aldehyde-modified starch. The mass concentration of acetic acid in the acetic acid solution was 1.5%.

[0044] (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 mixed evenly 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 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.

[0045] (3) The solid particles obtained in step (2) are placed in a curdlan dispersion having a mass concentration of 8%, and subjected to vacuum impregnation treatment at -0.08 MPa for 30 minutes, followed by removal and drying to obtain a solid slow-release scale inhibitor having antibacterial function. The curdlan dispersion is prepared by ultrasonically dispersing the curdlan in deionized water at 40°C for 2 hours.

[0046] Comparative Example 1

[0047] This comparative example provides a scale inhibitor material, the preparation method of which is substantially the same as that of Example 1, except that in step (2), an equal mass of chitosan is used instead of chitosan quaternary ammonium salt, and the remaining steps are the same as those of Example 1.

[0048] Comparative Example 2

[0049] This comparative example provides a scale inhibition material, the preparation method of which comprises the following steps:

[0050] (1) By weight, 0.6 parts of starch, 2.4 parts of chitosan quaternary ammonium salt, and 1.5 parts of a scale-inhibiting and antibacterial component were uniformly mixed in 60 parts of deionized water to obtain a mixed solution. The scale-inhibiting and antibacterial component consisted of polyepoxysuccinic acid, sodium lignin sulfonate, and paeonol in a mass ratio of 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.

[0051] (2) The solid particles obtained in step (1) are placed in a 6% by mass concentration of curdlan dispersion, and vacuum impregnated at -0.08 MPa for 30 minutes, and then removed and dried to obtain a solid slow-release scale inhibitor with antibacterial function. The curdlan dispersion is prepared by ultrasonically dispersing the curdlan in deionized water at 40°C for 2 hours.

[0052] Comparative Example 3

[0053] This comparative example provides a scale inhibitor material, the preparation method of which 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.

[0054] Comparative Example 4

[0055] This comparative example provides a scale inhibitor material, the preparation method of which is substantially 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.

[0056] Test Example 1: Antibacterial Performance Test

[0057] This experiment tests the antibacterial performance of scale inhibitors to evaluate the antibacterial effect of different scale inhibitors. The heterotrophic bacteria used in the experiment were enriched from the on-site circulating water. After enrichment, the heterotrophic bacteria were resuspended in PBS to obtain an effective bacterial concentration of 1×10 6 CFU / mL of heterotrophic bacterial suspension. The composition of the heterotrophic culture medium is: 15g agar, 10g peptone, 3g beef extract, 3g sodium chloride, and distilled water to 1L. The pH is adjusted to 7.0 and sterilized before use.

[0058] (1) Comparison of the antibacterial effect of scale inhibitors 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 material from Example 1 (10, 20, 40, and 80 mg / L) was added. A control group without the scale inhibitor was also set up. The samples obtained after adding the scale inhibitor were cultured in a biochemical incubator at 37±1°C. Samples were taken on the first, 10th, 20th, and 30th day of culture and inoculated into heterotrophic culture medium. The heterotrophic bacteria count was determined, and the inhibition rate was calculated. The results were averaged over three experiments. The results are shown in Table 1.

[0059] Table 1. Comparison of antibacterial effects of scale inhibitors in Example 1 at different concentrations

[0060]

[0061] Table 1 shows that when the scale inhibitor concentration is less than 40 mg / L, the antibacterial rate is low. When the scale inhibitor concentration exceeds 40 mg / L, it effectively inhibits the growth of heterotrophic bacteria, achieving excellent antibacterial effects. However, when the scale inhibitor concentration is increased to 80 mg / L, the increase in antibacterial effect compared to 40 mg / L is minimal. Therefore, to control the cost of the water treatment agent, the scale inhibitor dosage is set at 40 mg / L.

[0062] (2) Comparison of the antibacterial effect of different scale inhibitors 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 inhibitor materials of Examples 1-4 and Comparative Examples 1-4 (concentration 40 mg / L) were added, respectively. A control group without scale inhibitor was also set up. The samples obtained after adding the scale inhibitor were cultured in a biochemical incubator at 37±1°C. Samples were taken on the 1st, 10th, 20th, 30th, and 60th day of culture and inoculated into heterotrophic culture medium. The heterotrophic bacteria count was determined, and the inhibition rate was calculated. The results were averaged over three experiments. The results are shown in Table 2.

[0063] Table 2. Comparison of antibacterial effects of scale inhibitors of Examples 1 to 4 and Comparative Examples 1 to 4

[0064]

[0065] As shown in Table 2, the scale inhibitor materials of Examples 1-4 of the present invention exhibit excellent antibacterial effects within 1-10 days, but their antibacterial effects decline somewhat after 20 days, and even more significantly after 30 days. However, the antibacterial rates of the scale inhibitor materials of Examples 1-4 still exceed 80% after 30 days of action, and exceed 72% after 60 days of action, meeting the requirement for long-term antibacterial effects. A comprehensive comparison of the examples and comparative examples shows that while the antibacterial effects of the scale inhibitor materials of Comparative Examples 1-4 are excellent within 1-10 days, meeting the antibacterial requirements, the antibacterial rates of the scale inhibitor materials of Comparative Examples 1-4 decrease significantly after 10 days. This demonstrates that the scale inhibitor materials of the present invention effectively inhibit bacterial growth and can exert a more sustained effect in reducing bacterial reproduction, i.e., they exhibit excellent long-term antibacterial effects.

[0066] Test Example 2: Scale Inhibition Performance Test

[0067] 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 measured as follows: 1g of the scale inhibition material sample was weighed, packed in different gauze bags, and then placed in a 1L simulated water environment (containing 300mg / L of 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, and 20mL of supernatant was taken after 1 day to measure the scale inhibition rate. After sampling, the gauze bag was taken out and put back into the newly configured 1000mL simulated water environment. The scale inhibition test was carried out in this cycle. Sampling was carried out on the 1st, 10th, 20th, 40th and 60th days respectively, and the scale inhibition rate was measured. The scale inhibition rate change curve was drawn. The results are shown as follows Figure 1 shown.

[0068] like Figure 1 As shown, the scale inhibition material provided in Example 1 of the present invention achieved a scale inhibition rate of 74.5% after a 60-day test period. However, the scale inhibition rates of the scale inhibition materials provided in Comparative Examples 1-4 decreased significantly. This demonstrates that the scale inhibition material provided by the present invention exhibits excellent scale inhibition effectiveness and a long sustained-release period.

[0069] In summary, the preparation method of the solid slow-release scale-inhibiting material with antibacterial function provided by the present invention can effectively improve the structural stability of the scale-inhibiting material through two coating treatments, 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.

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) Starch is oxidized with sodium periodate to obtain aldehyde-modified starch; (2) The aldehyde-modified starch, chitosan quaternary ammonium salt and anti-scaling and antibacterial components are uniformly mixed in water to obtain a mixed solution; the pH of the mixed solution is adjusted to 8-9, and a cross-linking reaction is carried out at 40-60°C under stirring conditions. After the reaction is completed, the obtained product is filtered, washed with water, dried, and then granulated to obtain solid particles; (3) placing the solid particles obtained in step (2) in a curdlan dispersion for vacuum impregnation treatment, and then drying to obtain a solid slow-release scale-inhibiting material with antibacterial function; Wherein, in step (2), the mass ratio of the formaldehyde starch, chitosan quaternary ammonium salt, scale inhibition and antibacterial component, and water is (0.4-0.8): (2.3-2.5): (1.4-1.6): (55-65); the scale inhibition and antibacterial component comprises the following raw materials in parts by mass: 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; in step (3), the mass concentration of the curdlan in the curdlan dispersion is 4%-8%.

2. The method for preparing a solid slow-release scale-inhibiting 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 at 30-40° C. in the dark for 6-10 hours, and then the reaction solution is dialyzed and freeze-dried to obtain aldehyde-modified starch.

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

5. The method for preparing a solid slow-release scale-inhibiting 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.

6. The method for preparing a solid slow-release scale-inhibiting material with antibacterial function according to any one of claims 1 to 5, characterized in that: In step (3), the vacuum degree of the vacuum impregnation is -0.05~-0.095MPa, and the time of the vacuum impregnation is 20~40min.

7. A solid slow-release scale-inhibiting material with antibacterial function prepared by the preparation method according to any one of claims 1 to 6.

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