Disinfectant for treating sewage from marine aquaculture and livestock and poultry breeding and preparation method thereof

Abstract

The present application relates to the technical field of disinfectant, in particular to a disinfectant for marine aquaculture and livestock breeding wastewater treatment and a preparation method thereof; the disinfectant is granular and is composed of the following components in parts by weight: potassium hydrogen persulfate composite salt 55-65 parts, citric acid 15-25 parts, sodium citrate 2-8 parts, surfactant 2-28 parts, and adhesive 1-5 parts; by selecting potassium hydrogen persulfate composite salt, citric acid and sodium citrate instead of conventional sulfamic acid, sodium chloride and phosphate, and combining with environment-friendly adhesive (hydroxypropyl methyl cellulose, etc.), the secondary pollution of water body caused by disinfectant accessories is effectively avoided while the disinfection effect is ensured. The products of citric acid and sodium citrate after decomposition are carbon dioxide and water, which do not pollute water body; hydroxypropyl methyl cellulose is a biodegradable material and is environment-friendly.

Description

Technical Field

[0001] This invention relates to the field of disinfectant technology, specifically to disinfectants and preparation methods for treating wastewater from marine aquaculture and livestock farming. Background Technology

[0002] Potassium persulfate compound salt (potassium persulfate compound salt) is a stable, highly efficient, and safe acidic oxidant with broad-spectrum bactericidal activity against pathogenic microorganisms such as bacteria, viruses, and fungi. Potassium persulfate disinfectant was recognized as a highly effective disinfectant by the US EPA in 1989 and is widely used in aquaculture, livestock farming, wastewater treatment, and medical and health fields.

[0003] Currently, potassium persulfate disinfectants on the market are mainly in powder form, which has the following main shortcomings: First, powder products have a large specific surface area, making them extremely susceptible to moisture absorption. Potassium persulfate compound salts are highly sensitive to humidity; during storage, the powder easily absorbs moisture, clumps, and swells, leading to rapid decomposition and loss of the active ingredients. While existing technologies include adding anti-caking agents to prevent clumping (such as CN108184828A), this additional addition increases the complexity of the formulation, and some anti-caking agents are not environmentally friendly substances.

[0004] Secondly, powder products are prone to generating dust during use. When powder disinfectants are added in open environments such as livestock and poultry farms and aquaculture ponds, the powder is easily blown away by the wind, which not only causes the loss and waste of effective ingredients, but also irritates and harms the respiratory system of operators.

[0005] Third, powder products have poor sinking properties in aquaculture applications. Potassium persulfate compound salt powder has a low density, and after being added to water, it floats on the surface or remains suspended in the water, making it difficult to quickly sink to the bottom and effectively disinfect pathogenic microorganisms. Since the main pathogenic microorganisms in aquaculture often accumulate in the pond sediment, the poor sinking property of powder directly affects the disinfection effect.

[0006] Fourth, existing granulation methods suffer from environmental unfriendliness or complex processes. For example, the potassium persulfate granules disclosed in CN108041072A contain polyaluminum sulfate and dibromohydantoin; the compound disinfectant disclosed in CN119302314A contains dichlorohydantoin microspheres, sodium chloride-coated granules, and sodium hexametaphosphate; CN105360162A uses a polymer slow-release carrier to coat sodium chloride to prevent moisture absorption. These methods either add chlorine or phosphorus-containing components, which could cause secondary pollution in aquaculture and livestock wastewater treatment, or the coating process is complex and costly. Therefore, we propose a disinfectant and its preparation method for marine aquaculture and livestock wastewater treatment. Summary of the Invention

[0007] The purpose of this invention is to address the shortcomings of existing potassium bisulfate disinfectant powder, such as easy moisture absorption, easy dispersion, and poor settling properties, as well as the environmental unfriendliness and complex processes of existing granulation methods, and to provide a disinfectant for the treatment of marine aquaculture and livestock and poultry aquaculture wastewater and its preparation method.

[0008] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: In a first aspect, the present invention provides a disinfectant for treating wastewater from marine aquaculture and livestock farming, the disinfectant being in granular form and composed of the following components in parts by weight: Potassium persulfate compound salt 55-65 parts, citric acid 15-25 parts, sodium citrate 2-8 parts, surfactant 2-28 parts, binder 1-5 parts; The particle size of the disinfectant is 0.5~3.0mm.

[0009] Preferably, the product is composed of the following components in the indicated weight ratios: 65 parts potassium persulfate compound salt, 20 parts citric acid, 5 parts sodium citrate, 10 parts surfactant, and 2.5 parts binder.

[0010] Preferably, the surfactant is sodium dodecylbenzenesulfonate.

[0011] Preferably, the adhesive is one or more of hydroxypropyl methylcellulose, polyvinylpyrrolidone, or pregelatinized starch; more preferably, it is hydroxypropyl methylcellulose.

[0012] Preferably, the particle size of the disinfectant is 1.0~2.0 mm.

[0013] Preferably, the bulk density of the disinfectant is 0.6~1.2 g / cm³. 3 .

[0014] Secondly, the present invention provides a method for preparing the above-mentioned disinfectant, comprising the following steps: S1. Raw material pretreatment: Potassium persulfate compound salt, citric acid, sodium citrate, and sodium dodecylbenzene sulfonate are pulverized separately and passed through an 80-120 mesh sieve for later use. S2. Preparation of adhesive solution: Add the adhesive to purified water and stir until completely dissolved in a water bath at 40~60℃ to prepare an adhesive solution with a mass fraction of 2%~8%. S3. Mixing to form a soft material: Weigh each raw material after S1 treatment according to the ratio, put them into a mixer, and mix at a speed of 100~300 rpm for 10~30 minutes; During the mixing process, spray in the adhesive solution prepared in S2, the amount of which is 10%~30% of the total weight of the raw materials, and continue mixing until a soft material is formed. S4. Extrusion granulation: The soft material obtained in S3 is fed into an extrusion granulator and extruded at a speed of 20~100 rpm. The extrusion head diameter is 0.6~3.5 mm, the extrusion pressure is 0.2~1.0 MPa, and the extrusion temperature is room temperature~40℃ to obtain wet granules. S5. Rounding and shaping: The wet granules obtained in S4 are put into a rounding machine and rolled at a speed of 200~800 rpm for 5~20 minutes to make the granules spherical or near-spherical. S6. Drying: Place the spherical particles obtained in S5 into a drying device and dry them at a temperature of 40~60℃ until the moisture content is ≤3%; S7. Sieving: The dried particles from S6 are sieved to collect particles with a diameter range of 0.5~3.0mm to obtain the finished product of potassium persulfate disinfectant granules. S8. Packaging: The disinfectant granules obtained in S7 are sealed and packaged in an environment with a relative humidity of ≤30%.

[0015] Preferably, the adhesive solution in step S3 is an aqueous solution of hydroxypropyl methylcellulose with a mass fraction of 3% to 5%.

[0016] Preferably, the extruder head diameter in step S4 is 1.0~2.5mm and the extrusion pressure is 0.3~0.6MPa.

[0017] Preferably, the drying temperature in step S6 is 45~55℃ and the drying time is 30~120 minutes.

[0018] Preferably, in step S7, particles with a diameter range of 1.0 to 2.0 mm are collected.

[0019] Compared with the prior art, the beneficial effects of the present invention are: 1. This invention uses potassium persulfate compound salt, citric acid, and sodium citrate instead of conventional aminosulfonic acid, sodium chloride, and phosphates, combined with environmentally friendly adhesives (such as hydroxypropyl methylcellulose), to effectively avoid secondary pollution of water bodies caused by disinfectant excipients while ensuring disinfection efficacy. The decomposition products of citric acid and sodium citrate are carbon dioxide and water, which do not pollute water bodies; hydroxypropyl methylcellulose is a biodegradable material and is environmentally friendly.

[0020] 2. This invention uses an extrusion and sphericalization process to form disinfectant into spherical or near-spherical granules. The specific surface area of ​​these granules is much smaller than that of powders, significantly reducing the probability of moisture absorption and greatly improving storage stability. Furthermore, the granular product does not clump or bulge during storage, exhibits good flowability, and is easy to package, transport, and automatically dispense.

[0021] 3. The granular product of this invention produces no dust during use, avoiding the loss of effective ingredients and potential health hazards to operators caused by powder addition. The bulk density of the granules is 0.6~1.2 g / cm³. 3 It can sink quickly after being put into the water and effectively disinfect pathogenic microorganisms in the bottom sediment, making it especially suitable for bottom sediment improvement in aquaculture ponds and wastewater treatment in livestock and poultry farming. Detailed Implementation

[0022] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Unless otherwise specified, the embodiments and features in the embodiments of this application can be combined with each other. 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.

[0023] The sources of the raw materials used in the various embodiments of this invention are as follows: Potassium peroxymonosulfate compound salt (potassium peroxymonosulfate compound salt, active oxygen content ≥4.5%): purchased from Shandong Jinglan Environmental Protection Technology Co., Ltd. or Aotu (Shandong) Biotechnology Co., Ltd., industrial grade; Citric acid (citric acid monohydrate, food grade, standard GB 1886.235-2016): purchased from Shandong Yingxuan Industrial Co., Ltd., food grade; Sodium citrate (food grade, standard GB 1886.25-2016): purchased from Shandong Yingxuan Industrial Co., Ltd., food grade; Sodium dodecylbenzenesulfonate (industrial grade, purity ≥90%): purchased from Zanyu Technology Group Co., Ltd., industrial grade; Hydroxypropyl methylcellulose (HPMC, pharmaceutical grade, model 2208, methoxy content 19%~24%, hydroxypropoxy content 4%~12%): purchased from Shandong Heda Group Co., Ltd., pharmaceutical grade; Polyvinylpyrrolidone (PVP) K30 (pharmaceutical grade): purchased from BASF in Germany or repackaged domestically, pharmaceutical grade; pregelatinized starch (pharmaceutical grade): purchased from Weifang Shengtai Pharmaceutical Co., Ltd., pharmaceutical grade; purified water: prepared in the laboratory, conforming to the purified water standards of the Pharmacopoeia of the People's Republic of China (2020 edition).

[0024] The present invention will describe the above technical solution in detail through the following embodiments: Example 1

[0025] Disinfectant for treating wastewater from marine aquaculture and livestock farming, composed of the following components in parts by weight: Potassium persulfate compound salt 65 parts, citric acid 20 parts, sodium citrate 5 parts, sodium dodecylbenzene sulfonate 10 parts, hydroxypropyl methylcellulose 2.5 parts.

[0026] The preparation method is as follows: S1. Raw material pretreatment: Potassium persulfate compound salt, citric acid, sodium citrate, and sodium dodecylbenzene sulfonate are pulverized separately and passed through a 100-mesh sieve for later use. S2. Preparation of adhesive solution: Add 2.5 parts of hydroxypropyl methylcellulose to purified water and stir until completely dissolved in a 50°C water bath to prepare an adhesive solution with a mass fraction of 4%. S3. Mixing to form a soft material: Weigh each raw material after S1 treatment according to the ratio, put them into the mixer, and mix at a speed of 200 rpm for 20 minutes; during the mixing process, slowly spray in the adhesive solution prepared in S2, the amount of which is 20% of the total weight of the raw materials, and continue mixing until a soft material that can be formed "by hand into a ball and easily dispersed by light pressure" is formed. S4. Extrusion granulation: The soft material obtained in S3 is fed into an extrusion granulator and extruded at a speed of 50 rpm. The extruder head diameter is 1.5 mm, the extrusion pressure is 0.5 MPa, and the extrusion temperature is 30℃ to obtain cylindrical wet granules. S5. Rounding: The wet granules obtained in S4 are put into a rounding machine and rolled at a speed of 500 rpm for 10 minutes to make the granules spherical. S6. Drying: Place the spherical particles obtained in S5 into a fluidized bed dryer and dry them at 50℃ until the moisture content is ≤3%; S7. Sieving: The dried particles from S6 are sieved to collect particles with a diameter range of 1.0~2.0mm to obtain the finished product of potassium persulfate disinfectant granules. S8. Packaging: The disinfectant granules obtained in S7 are sealed and packaged in an environment with a relative humidity of ≤30%.

[0027] Example 2

[0028] Disinfectant for treating wastewater from marine aquaculture and livestock farming, composed of the following components in parts by weight: 55 parts potassium persulfate compound salt, 25 parts citric acid, 8 parts sodium citrate, 7 parts sodium dodecylbenzenesulfonate, and 5 parts polyvinylpyrrolidone.

[0029] The preparation method is as follows: S1. Raw material pretreatment: Potassium persulfate compound salt, citric acid, sodium citrate, and sodium dodecylbenzene sulfonate are pulverized separately and passed through an 80-mesh sieve for later use. S2. Preparation of adhesive solution: Add 5 parts of polyvinylpyrrolidone to purified water and stir until completely dissolved in a 60°C water bath to prepare an adhesive solution with a mass fraction of 8%. S3. Mixing to form a soft material: Weigh each raw material treated in S1 according to the ratio, put them into the mixer, and mix at a speed of 100 rpm for 30 minutes; during the mixing process, spray in the adhesive solution prepared in S2, the amount of which is 30% of the total weight of the raw materials, and continue mixing until a soft material is formed. S4. Extrusion granulation: The soft material obtained in S3 is fed into an extrusion granulator and extruded at a speed of 20 rpm. The extruder head diameter is 3.5 mm, the extrusion pressure is 0.2 MPa, and the extrusion temperature is room temperature to obtain wet granules. S5. Rounding: The wet granules obtained in S4 are put into a rounding machine and rolled at a speed of 200 rpm for 20 minutes to make the granules into a spherical shape. S6. Drying: Place the spherical particles obtained in S5 in an oven and dry them at 40℃ until the moisture content is ≤3%; S7. Sieving: The dried particles from S6 are sieved to collect particles with a diameter range of 0.5~3.0mm. S8. Packaging: The disinfectant granules obtained in S7 are sealed and packaged in an environment with a relative humidity of ≤30%.

[0030] Example 3

[0031] Disinfectant for treating wastewater from marine aquaculture and livestock farming, composed of the following components in parts by weight: 60 parts potassium persulfate compound salt, 18 parts citric acid, 3 parts sodium citrate, 16 parts sodium dodecylbenzene sulfonate, and 3 parts pregelatinized starch.

[0032] The preparation method is as follows: S1. Raw material pretreatment: Potassium persulfate compound salt, citric acid, sodium citrate, and sodium dodecylbenzene sulfonate are pulverized separately and passed through a 120-mesh sieve for later use. S2. Preparation of adhesive solution: Add 3 parts of pregelatinized starch to purified water and stir until completely dissolved in a 40°C water bath to prepare an adhesive solution with a mass fraction of 2%. S3. Mixing to form a soft material: Weigh each raw material after S1 treatment according to the ratio, put them into the mixer, and mix at a speed of 300 rpm for 10 minutes; during the mixing process, spray in the adhesive solution prepared in S2, the amount of which is 10% of the total weight of the raw materials, and continue mixing until a soft material is formed. S4. Extrusion granulation: The soft material obtained in S3 is fed into an extrusion granulator and extruded at a speed of 100 rpm. The extruder head diameter is 0.6 mm, the extrusion pressure is 1.0 MPa, and the extrusion temperature is 40℃ to obtain wet granules. S5. Rounding and shaping: The wet granules obtained in S4 are put into a rounding machine and rolled at a speed of 800 rpm for 5 minutes to make the granules spherical. S6. Drying: Place the spherical particles obtained in S5 into a fluidized bed dryer and dry them at 60℃ until the moisture content is ≤3%; S7. Sieving: The dried particles from S6 are sieved to collect particles with a diameter range of 0.5~2.0mm. S8. Packaging: The disinfectant granules obtained in S7 are sealed and packaged in an environment with a relative humidity of ≤30%.

[0033] Example 4

[0034] Disinfectant for treating wastewater from marine aquaculture and livestock farming, composed of the following components in parts by weight: Potassium persulfate compound salt 62 parts, citric acid 22 parts, sodium citrate 4 parts, sodium dodecylbenzene sulfonate 9 parts, hydroxypropyl methylcellulose 3 parts.

[0035] The preparation method is as follows: S1. Raw material pretreatment: Potassium persulfate compound salt, citric acid, sodium citrate, and sodium dodecylbenzene sulfonate are pulverized separately and passed through a 100-mesh sieve for later use. S2. Preparation of adhesive solution: Add 3 parts of hydroxypropyl methylcellulose to purified water and stir until completely dissolved in a 55°C water bath to prepare an adhesive solution with a mass fraction of 5%. S3. Mixing to form a soft material: Weigh each raw material treated in S1 according to the ratio, put them into the mixer, and mix at a speed of 250 rpm for 15 minutes; during the mixing process, slowly spray in the adhesive solution prepared in S2, the amount of which is 25% of the total weight of the raw materials, and continue mixing until a soft material that can be formed "by hand into a ball and easily dispersed by light pressure" is formed. S4. Extrusion granulation: The soft material obtained in S3 is fed into an extrusion granulator and extruded at a speed of 60 rpm. The extruder head diameter is 2.0 mm, the extrusion pressure is 0.4 MPa, and the extrusion temperature is 35℃ to obtain cylindrical wet granules. S5. Rounding and shaping: The wet granules obtained in S4 are put into a rounding machine and rolled at a speed of 600 rpm for 8 minutes to make the granules spherical. S6. Drying: Place the spherical particles obtained in S5 into a fluidized bed dryer and dry them at 55℃ until the moisture content is ≤3%; S7. Sieving: The dried particles from S6 are sieved to collect particles with a diameter range of 1.0~2.0mm. S8. Packaging: The disinfectant granules obtained in S7 are sealed and packaged in an environment with a relative humidity of ≤30%.

[0036] Comparative Example 1 This comparative example provides a potassium persulfate disinfectant in powder form (i.e., the same formulation powder without granulation), composed of the following components in parts by weight: 65 parts potassium persulfate compound salt, 20 parts citric acid, 5 parts sodium citrate, and 10 parts sodium dodecylbenzene sulfonate.

[0037] The preparation method is as follows: potassium persulfate compound salt, citric acid, sodium citrate, and sodium dodecylbenzene sulfonate are pulverized separately, passed through a 100-mesh sieve, weighed according to the ratio, and put into a mixer. The mixture is mixed at a speed of 200 rpm for 20 minutes. After being mixed evenly, it is directly packaged to obtain potassium persulfate disinfectant powder.

[0038] The difference between this comparative example and Example 1 is that no binder is added, no granulation process is performed, and the product is in powder form.

[0039] Comparative Example 2 This comparative example provides potassium persulfate disinfectant granules with added traditional excipients, composed of the following components in parts by weight: 55 parts potassium persulfate compound salt, 10 parts aminosulfonic acid, 3 parts sodium chloride, 15 parts sodium hexametaphosphate, 10 parts sodium dodecylbenzenesulfonate, and 2.5 parts hydroxypropyl methylcellulose.

[0040] The preparation method is the same as in Example 1.

[0041] The difference between this comparative example and Example 1 is that it uses traditional aminosulfonic acid, sodium chloride, and sodium hexametaphosphate as the chain reaction system and pH buffer system, instead of the environmentally friendly citric acid / sodium citrate system used in this invention.

[0042] Comparative Example 3 This comparative example provides potassium persulfate disinfectant granules that are not spheroidized (i.e., directly dried after extrusion without spheroidization), composed of the following components in parts by weight: Potassium persulfate compound salt 65 parts, citric acid 20 parts, sodium citrate 5 parts, sodium dodecylbenzene sulfonate 10 parts, hydroxypropyl methylcellulose 2.5 parts.

[0043] The preparation method is as follows: S1~S4 are the same as in Example 1; step S5 is omitted, and the cylindrical wet particles obtained in S4 are directly dried (S6) and sieved (S7); S8 is the same as in Example 1.

[0044] The difference between this comparative example and Example 1 is that the rounding step is omitted, and the product is cylindrical particles instead of spherical particles.

[0045] Comparative Example 4 This comparative example provides potassium persulfate disinfectant granules with added chlorine-containing excipients, composed of the following components in parts by weight: 40 parts potassium persulfate compound salt, 15 parts dichlorohydantoin microspheres, 8 parts sodium chloride-coated particles, 12 parts sodium hexametaphosphate, 10 parts sodium dodecylbenzenesulfonate, and 2.5 parts hydroxypropyl methylcellulose.

[0046] The preparation method is the same as in Example 1.

[0047] The difference between this comparative example and Example 1 is that chlorine-containing components such as dichlorohydantoin microspheres and sodium chloride-encapsulated particles were added, making it a chlorine-containing disinfectant system.

[0048] Experimental Example In the following experimental examples, the experimental methods used were all performed in accordance with relevant national and industry standards: (1) pH value determination of disinfectant: Refer to the pH value determination method in the "Disinfection Technical Specifications" (2002 edition); (2) Determination of reactive oxygen species content: Refer to the method for determination of reactive oxygen species content (iodometric method) in T / FDSA 028-2021 "General Technical Standard for Potassium Persulfate Disinfectant"; (3) Moisture content determination: Refer to the moisture determination method (drying method) in the Pharmacopoeia of the People's Republic of China (2020 edition); (4) Quantitative bacterial kill test: Refer to the quantitative bacterial kill test method in the "Disinfection Technical Specifications" (2002 edition); (5) Neutralizing agent identification test: Refer to the neutralizing agent identification test method in the "Disinfection Technical Specifications" (2002 edition).

[0049] Experimental Example 1: Basic Performance Indicators of Disinfectant Granules in Each Example Disinfectant granules were prepared according to the formulations and preparation methods of Examples 1-4, and their basic performance indicators were determined according to the testing methods in T / FDSA 028-2021 "General Technical Standard for Potassium Persulfate Disinfectant". Comparative Example 1 (with the same formulation powder) was used as a control. The results are shown in Table 1.

[0050] Table 1. Basic performance indicators of disinfectant granules in each embodiment and powder in Comparative Example 1

[0051] Table 1 shows that the disinfectant granules prepared in Examples 1-4 all had a moisture content ≤2.5%, a pH value of 1% aqueous solution within the suitable range of 2.35-2.65, and an active oxygen content ≥4.5%, meeting the requirements of T / FDSA 028-2021 standard. Compared with the powder of Comparative Example 1, the bulk density of the granule products (0.78~0.92 g / cm³) was significantly higher. 3 The concentration was significantly higher than that of the powder (0.55 g / cm³). 3 This is beneficial for the sedimentation of particles in water.

[0052] Experimental Example 2: Comparison of hygroscopicity between granular and powder products The disinfectant granules prepared in Example 1 and Comparative Example 1 (with the same formula powder) were placed in the open under the same conditions (temperature 25°C, relative humidity 75%), and samples were taken periodically to determine the moisture content and active oxygen content. The results are shown in Table 2.

[0053] Table 2 Comparison of hygroscopicity and reactive oxygen species stability between the granules of Example 1 and the powder of Comparative Example 1

[0054] As shown in Table 2, under the same temperature and humidity conditions, the moisture content of the granules in Example 1 increased significantly slower than that of the powder in Comparative Example 1. After 30 days, the moisture content of the granules was 6.2%, while that of the powder reached 31.5%. Correspondingly, the active oxygen retention rate of the granules (80.1%) was significantly higher than that of the powder (32.4%). This indicates that granulation treatment effectively reduced the moisture absorption rate of the product and significantly improved its storage stability.

[0055] Experimental Example 3: Sinking Test of Granular Products Take 10g each of the disinfectant granules prepared in Examples 1-4 and the powder in Comparative Example 1, and evenly sprinkle them into a transparent glass tank containing 1L of tap water (water depth 25cm) from a height of 30cm above the water surface. Record the time it takes for the granules / powder to completely sink to the bottom and observe the sinking situation. The results are shown in Table 3.

[0056] Table 3 Comparison of sedimentation properties of particles from each embodiment and powder from Comparative Example 1

[0057] As shown in Table 3, the sinking performance of the granular products in Examples 1-4 is far superior to that of the powder in Comparative Example 1. The granules sink completely within 8-20 seconds after being added to water, while most of the powder floats or remains suspended, with an extremely low sinking rate. This indicates that granulation significantly improves the sinking performance of the disinfectant in aquaculture applications, which is beneficial for the effective elimination of pathogenic microorganisms in the substrate.

[0058] Experiment Example 4: Comparison of the flowability of granular products The flowability of the disinfectant granules prepared in Examples 1-4 and the powder of Comparative Example 1 was determined using the angle of repose method. The samples were evenly poured from a fixed height (5 cm) onto a horizontal plate to form a conical accumulation. The height of the cone and the radius of its base were measured, and the angle of repose (tanθ = h / r) was calculated. A smaller angle of repose indicates better flowability. The results are shown in Table 4.

[0059] Table 4 Comparison of flowability of granules from each example and powder from Comparative Example 1

[0060] As shown in Table 4, the angle of repose of the granules in Examples 1-4 is ≤33°, indicating excellent flowability; while the angle of repose of the powder in Comparative Example 1 reaches 45.8°, indicating poor flowability and a tendency to clump during storage and use. Granulation significantly improves the flowability of the product.

[0061] Experimental Example 5: Neutralizing Agent Identification Test Referring to the neutralizing agent identification test method in the "Disinfection Technical Specifications" (2002 edition), 0.5% sodium thiosulfate was used as the neutralizing agent, and Escherichia coli (ATCC 8099) was used as the test strain. A 1:200 diluted aqueous solution of disinfectant granules from Example 1 was used. After mixing the disinfectant and bacterial suspension and allowing it to react for 0.5 min, the neutralizing agent was added and reacted for 10 min. The experiment was divided into 4 groups and repeated 3 times. The results are shown in Table 5.

[0062] Table 5 Results of Neutralizer Identification Tests

[0063] Groups 1, 2, and 3 all showed similar bacterial growth, ranging from 15 to 300 CFU / plate; Group 4 showed no bacterial growth. The inter-group colony error rate was 2.58%, less than 15%, meeting the requirements of the "Disinfection Technical Specifications". The results indicate that 0.5% sodium thiosulfate can effectively neutralize the bactericidal effect of a 1:200 concentration of disinfectant granules in aqueous solution on Escherichia coli, and the neutralizing agent and its products have no bactericidal effect on the bacterial suspension and no adverse effect on the culture medium.

[0064] Experiment Example 6: Quantitative Bacterial Killing Test Referring to the quantitative bacterial killing test method in the "Disinfection Technical Specifications" (2002 edition), Staphylococcus aureus (ATCC 6538) and Escherichia coli (ATCC 8099) were used as test strains. The disinfectant granules from Example 1 were prepared into disinfectant aqueous solutions of 1:200, 1:400, 1:600, and 1:800 using sterile hard water. 4.5 mL of each concentration of disinfectant solution was placed in a test tube, and 0.5 mL of bacterial suspension (containing approximately 1 × 10⁻⁶ bacteria) was added. 8 (The solution contained 50% bovine serum as an organic interfering agent). After shaking well, 0.5 mL of the mixture was added to 4.5 mL of 0.5% sodium thiosulfate neutralizing agent at 5 min, 10 min, and 30 min respectively. After neutralization for 10 min, viable bacteria were counted and cultured. The diluted solution was used as a positive control. The results are shown in Tables 6 and 7.

[0065] Table 6. Killing effect of disinfectant granules in Example 1 on Staphylococcus aureus

[0066] Table 7. Killing effect of disinfectant granules in Example 1 on Escherichia coli.

[0067] Tables 6 and 7 show that the 1:200 diluted disinfectant granules achieved a 100.0% bactericidal rate against Staphylococcus aureus and Escherichia coli after 5 minutes of contact; the 1:400 diluted solution achieved 98.5% and 99.2% bactericidal rates against the two bacteria after 30 minutes of contact; the 1:600 ​​and 1:800 dilutions showed relatively weaker bactericidal effects. The reason why higher dilution ratios result in lower bactericidal effects is twofold: firstly, the disinfectant concentration decreases; secondly, as the dilution ratio increases, the pH of the disinfectant solution rises, leading to an increase in HSO5. - Rapid decomposition leads to a decrease in the content of effective ingredients.

[0068] Experiment Example 7: Comparison of the stability and bactericidal effect of different disinfectant formulations The disinfectants prepared in Example 1 and Comparative Examples 1-4 were left exposed for 30 days under the same conditions (temperature 25°C, relative humidity 75%). The moisture content, active oxygen retention rate, and bactericidal rate against Staphylococcus aureus after a 1:200 dilution for 5 minutes were then measured. The results are shown in Table 8.

[0069] Table 8. Comparison of stability and bactericidal effect between Example 1 and Comparative Examples 1-4

[0070] As shown in Table 8: (1) Compared with Comparative Example 1 (same formulation powder), the moisture content of the particles in Example 1 (6.2%) was much lower than that of the powder (31.5%), and the active oxygen retention rate (80.1%) was much higher than that of the powder (32.4%), indicating that granulation treatment significantly improved storage stability. However, under the condition of 1:200 dilution for 5 min, the sterilization rate of both reached 100.0%, indicating that granulation treatment did not have an adverse effect on the disinfection effect.

[0071] (2) Compared with Comparative Example 2 (containing sulfamic acid / sodium chloride / phosphate particles), Example 1 has slightly better moisture content (6.2% vs 7.8%) and active oxygen retention rate (80.1% vs 75.3%). In addition, Example 1 does not contain sulfamic acid, sodium chloride, phosphate and other environmentally unfriendly components, thus avoiding secondary pollution of water bodies by chlorine-containing disinfectants and eutrophication of water bodies caused by phosphorus-containing components.

[0072] (3) Compared with Comparative Example 3 (unrounded particles), Example 1 has better moisture content (6.2% vs 8.5%) and active oxygen retention rate (80.1% vs 72.6%), indicating that rounding treatment makes the particles denser and the surface smoother, further reducing the specific surface area and moisture absorption probability.

[0073] (4) Compared with Comparative Example 4 (chlorine-containing auxiliary particles), Example 1 has significantly better moisture content (6.2% vs 9.2%) and active oxygen retention rate (80.1% vs 68.4%). Moreover, Example 1 does not contain chlorine-containing components such as dichlorohydantoin, thus avoiding the potential harm of chlorine-based disinfectants to aquatic animals and the environment.

[0074] (5) The sterilization rate of each comparative example reached 100.0% under the condition of 1:200 dilution and 5 min, indicating that each formula has a good sterilization effect when freshly prepared. However, after 30 days of storage, the active oxygen retention rate of Example 1 was the highest, indicating that its long-term storage stability was the best.

[0075] Experiment Example 8: Comparison of the effects of different formulations on environmental water bodies The disinfectants prepared in Example 1, Comparative Examples 2 and 4 were diluted with aquaculture pond water at a ratio of 1:200. The total phosphorus content and residual chlorine content in the water before and after dilution were measured (referring to GB 11893-1989 "Determination of Total Phosphorus in Water - Ammonium Molybdate Spectrophotometric Method" and GB / T 5750.11-2023 "Standard Examination Methods for Drinking Water - Disinfectant Indicators"). The results are shown in Table 9.

[0076] Table 9. Effects of different disinfectant formulations on aquaculture pond water.

[0077] As shown in Table 9, no total phosphorus or residual chlorine was detected in the diluted water of Example 1, indicating that the formulation of this invention does not cause secondary pollution to the water body. However, Comparative Example 2 contains sodium hexametaphosphate, which increased the total phosphorus in the diluted water by 2.35 mg / L, potentially leading to eutrophication. Comparative Example 4 contains chlorine-containing components such as dichlorohydantoin and sodium chloride, which produced residual chlorine of 1.56 mg / L in the diluted water, potentially causing stress and harm to aquatic animals.

[0078] Experimental Example 9: Accelerated stability test of disinfectant granules in each embodiment Referring to the stability test method in the "Disinfection Technical Specifications" (2002 edition), the disinfection granules prepared in Examples 1-4 were placed under accelerated test conditions (temperature 40℃, relative humidity 75%) for 6 months. The active oxygen content was measured periodically, and the active oxygen retention rate was calculated. The results are shown in Table 10.

[0079] Table 10. Accelerated stability test results of disinfectant granules in each example (reactive oxygen retention rate, %)

[0080] As shown in Table 10, the active oxygen retention rate of the disinfectant granules prepared in Examples 1 to 4 was ≥89.5% after 6 months under accelerated test conditions, with Example 1 showing the highest active oxygen retention rate (91.2%), indicating that the disinfectant granules prepared in this invention have good storage stability.

[0081] Experiment Example 10: Simulation Test of Actual Use Scenarios for Granular Products The following experiments were conducted to simulate real-world applications of wastewater treatment in marine aquaculture and livestock farming: (1) Simulation of aquaculture spraying: Take 10g of disinfectant granules from Example 1 and spread them evenly over a 1m area. 2 In a simulated aquaculture pond with a surface water depth of 50 cm, the settling of the particles was observed, and the concentration of reactive oxygen species (ROS) in the bottom water (5 cm below the bottom sediment) was measured. The results showed that the particles completely sank to the bottom within 15 seconds, and the ROS concentration in the bottom water reached 2.8 μg / mL after 30 minutes. It remained above 1.5 μg / mL after 2 hours, demonstrating its ability to continuously eliminate pathogenic microorganisms in the bottom sediment.

[0082] (2) Simulation of livestock and poultry breeding wastewater treatment: Livestock and poultry breeding wastewater (COD approximately 800 mg / L, ammonia nitrogen approximately 120 mg / L) was taken and disinfectant granules from Example 1 were added at a ratio of 1:400. After stirring and mixing, the mixture was allowed to stand for 30 minutes, and the changes in COD and ammonia nitrogen before and after treatment were measured. The results showed that the COD removal rate reached 62.5%, and the ammonia nitrogen removal rate reached 45.3%, indicating that the disinfectant granules of the present invention have a certain purification effect on livestock and poultry breeding wastewater.

[0083] (3) Solubility at different water temperatures: The complete dissolution time of the disinfectant granules of Example 1 at a dilution of 1:200 was measured at water temperatures of 15℃, 25℃, and 35℃. The results showed that the complete dissolution times at the three water temperatures were 4.5 min, 3.2 min, and 2.8 min, respectively, indicating that the disinfectant granules of the present invention can dissolve rapidly at different water temperatures, meeting the needs of aquaculture in different seasons and regions.

[0084] The above simulation test results show that the disinfectant granules of the present invention have good settling properties, sewage treatment effect and dissolution performance in actual use scenarios, and can meet the disinfection needs of marine aquaculture and livestock and poultry farming sewage treatment.

[0085] Based on the test results of Experiments 1-10 above: (1) The disinfectant granules prepared in Examples 1 to 4 have good basic performance indicators. The pH value of 1% aqueous solution is between 2.35 and 2.65, and the active oxygen content is ≥4.5%, which meets the requirements of T / FDSA 028-2021 standard.

[0086] (2) The hygroscopicity comparison test (Experimental Example 2) showed that after being placed at 25℃ / 75%RH for 30 days, the moisture content of the particles in Example 1 (6.2%) was much lower than that of the powder in Comparative Example 1 (31.5%), and the active oxygen retention rate (80.1%) was much higher than that of the powder (32.4%). Granulation treatment significantly improved storage stability.

[0087] (3) The sinking test (Experiment 3) showed that the granules of Examples 1 to 4 could sink completely within 8 to 20 seconds after being put into the water, while most of the powder of Comparative Example 1 floated or was suspended. Granulation treatment significantly improved the sinking performance in aquaculture applications.

[0088] (4) The flowability test (Experimental Example 4) showed that the angle of repose of the particles in Examples 1 to 4 was ≤33°, indicating excellent flowability; while the angle of repose of the powder in Comparative Example 1 reached 45.8°, indicating poor flowability.

[0089] (5) Neutralizing agent identification test (Experimental Example 5) shows that 0.5% sodium thiosulfate can effectively neutralize the bactericidal effect of disinfectant granule aqueous solution.

[0090] (6) The quantitative bacterial killing test (Experiment 6) showed that the 1:200 diluted disinfectant granule aqueous solution had a killing rate of 100.0% on Staphylococcus aureus and Escherichia coli after 5 min.

[0091] (7) Comparative tests of different formulations (Experiments 7-8) show that Example 1 of the present invention is superior to Comparative Examples 1-4 in terms of storage stability, active oxygen retention rate and environmental friendliness, and avoids secondary pollution of water bodies by chlorine-containing and phosphorus-containing components.

[0092] (8) Accelerated stability test (Experimental Example 9) shows that the active oxygen retention rate of Examples 1 to 4 is ≥89.5% after 6 months at 40℃ / 75%RH.

[0093] (9) The simulation test of actual use scenario (Experiment 10) shows that the disinfection granules of the present invention perform well in terms of splashing and settling, sewage treatment and dissolution at different water temperatures, and can meet the actual application needs.

[0094] In summary, the disinfectant and its preparation method for treating marine aquaculture and livestock and poultry aquaculture wastewater provided by this invention combine an environmentally friendly formulation with an extrusion spheronization granulation process. The resulting disinfectant granules have good storage stability, ease of use, settling properties, and disinfection effect, while avoiding secondary pollution of water bodies by traditional chlorine- and phosphorus-containing disinfectants. It has broad prospects for industrial application.

[0095] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.

Claims

1. A disinfectant for treating wastewater from marine aquaculture and livestock farming, characterized in that: The disinfectant is in granular form and consists of the following components in parts by weight: Potassium persulfate compound salt 55-65 parts, citric acid 15-25 parts, sodium citrate 2-8 parts, surfactant 2-28 parts, binder 1-5 parts; The particle size of the disinfectant is 0.5~3.0mm.

2. The disinfectant for treating marine aquaculture and livestock aquaculture wastewater as described in claim 1, characterized in that: It consists of the following components in the indicated weight proportions: 65 parts potassium persulfate compound salt, 20 parts citric acid, 5 parts sodium citrate, 10 parts surfactant, and 2.5 parts binder.

3. The disinfectant for treating marine aquaculture and livestock aquaculture wastewater as described in claim 1, characterized in that: The surfactant is sodium dodecylbenzenesulfonate.

4. The disinfectant for treating marine aquaculture and livestock aquaculture wastewater as described in claim 1, characterized in that: The adhesive is one or more of hydroxypropyl methylcellulose, polyvinylpyrrolidone, or pregelatinized starch.

5. The disinfectant for treating marine aquaculture and livestock aquaculture wastewater as described in claim 4, characterized in that: The adhesive is hydroxypropyl methylcellulose.

6. The disinfectant for treating marine aquaculture and livestock aquaculture wastewater as described in claim 1, characterized in that: The particle size of the disinfectant is 1.0~2.0mm.

7. The disinfectant for treating marine aquaculture and livestock aquaculture wastewater as described in claim 1, characterized in that: The bulk density of the disinfectant is 0.6~1.2 g / cm³. 3 .

8. A method for preparing a disinfectant for treating marine aquaculture and livestock aquaculture wastewater as described in any one of claims 1 to 7, characterized in that, Includes the following steps: S1. Raw material pretreatment: Potassium persulfate compound salt, citric acid, sodium citrate, and sodium dodecylbenzene sulfonate are pulverized separately and passed through an 80-120 mesh sieve for later use. S2. Preparation of adhesive solution: Add the adhesive to purified water and stir until completely dissolved in a water bath at 40~60℃ to prepare an adhesive solution with a mass fraction of 2%~8%. S3. Mixing to form a soft material: Weigh each raw material after S1 treatment according to the ratio, put them into a mixer, and mix at a speed of 100~300 rpm for 10~30 minutes; During the mixing process, spray in the adhesive solution prepared in S2, the amount of which is 10%~30% of the total weight of the raw materials, and continue mixing until a soft material is formed. S4. Extrusion granulation: The soft material obtained in S3 is fed into an extrusion granulator and extruded at a speed of 20~100 rpm. The extrusion head diameter is 0.6~3.5 mm, the extrusion pressure is 0.2~1.0 MPa, and the extrusion temperature is room temperature~40℃ to obtain wet granules. S5. Rounding and shaping: The wet granules obtained in S4 are put into a rounding machine and rolled at a speed of 200~800 rpm for 5~20 minutes to make the granules spherical or near-spherical. S6. Drying: Place the spherical particles obtained in S5 into a drying device and dry them at a temperature of 40~60℃ until the moisture content is ≤3%; S7. Sieving: The dried particles from S6 are sieved to collect particles with a diameter range of 0.5~3.0mm to obtain the finished product of potassium persulfate disinfectant granules. S8. Packaging: The disinfectant granules obtained in S7 are sealed and packaged in an environment with a relative humidity of ≤30%.

9. The method for preparing the disinfectant for treating marine aquaculture and livestock aquaculture wastewater as described in claim 8, characterized in that: The adhesive solution in step S3 is an aqueous solution of hydroxypropyl methylcellulose with a mass fraction of 3% to 5%; the extruder orifice diameter in step S4 is 1.0 to 2.5 mm, and the extrusion pressure is 0.3 to 0.6 MPa; the drying temperature in step S6 is 45 to 55 °C, and the drying time is 30 to 120 minutes.

10. The method for preparing the disinfectant for treating marine aquaculture and livestock aquaculture wastewater as described in claim 8, characterized in that: In step S7, particles with a diameter range of 1.0~2.0 mm are collected.

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