Aerobic granular sludge as well as culture method and application thereof

Abstract

The invention discloses aerobic granular sludge as well as a culture method and application thereof. The aerobic granular sludge is composed of basic sludge, nano silicon, nano magnet oxide, a modified polymer, chitosan, carbon quantum dots, graphene and polylactic acid, and all the components are ensured to be uniformly distributed and have excellent granular stability through an accurate proportioning and stirring process. According to the culture method, the stability, dispersity and water treatment efficiency of the aerobic granular sludge are remarkably improved, and the problems of poor stability, poor dispersity and limited treatment effect in a traditional sewage treatment process are solved. Besides, the invention further provides application of the aerobic granular sludge in water treatment, the application comprises the steps of granular sludge feeding, aeration operation and water quality monitoring, and high efficiency and stability of the water treatment process are ensured. Through the application of the invention, the sewage treatment effect can be effectively improved, and sustainable utilization of resources is realized.

Description

Technical Field

[0001] The present invention relates to the technical field of environmental engineering, and particularly to an aerobic granular sludge, a cultivation method thereof, and an application thereof. Background Art

[0002] With the increasingly serious water pollution problem, traditional sewage treatment methods have certain limitations in terms of treatment efficiency, stability, and cost. Especially when treating sewage with high concentrations of organic matter, the existing sewage treatment processes are not satisfactory in terms of sludge stability, sedimentation performance, and water quality improvement effect. These technologies often fail to provide long-term and stable water treatment effects, and the sludge treatment efficiency is low under high load or complex water quality conditions.

[0003] In addition, existing aerobic sludge technologies, especially granular sludge technologies, still have great room for improvement in terms of the stability, dispersibility, and biodegradability of granular sludge. Traditional aerobic granular sludge often has poor sedimentation performance, poor dispersibility, and aggregation between particles, resulting in limited practical application effects in the water treatment process. Especially in the removal of high-concentration organic pollutants and the stability of long-term operation, the existing technologies still face certain challenges.

[0004] Therefore, there is an urgent need for a new type of aerobic granular sludge with higher stability, good dispersibility, and stronger biodegradation ability, which can effectively improve sewage treatment efficiency, reduce sludge treatment costs, and enhance the long-term stability of sludge. Such aerobic granular sludge can not only improve the water treatment effect but also realize the sustainable utilization of sewage treatment resources. Summary of the Invention

[0005] The purpose of the present invention is to provide an aerobic granular sludge with high stability, good dispersibility, and enhanced functions, a cultivation method thereof, and an application thereof. During the water treatment process, the aerobic granular sludge can significantly improve sewage treatment efficiency and solve the problems existing in the traditional sludge treatment process in terms of stability, dispersibility, and treatment efficiency in the prior art.

[0006] To achieve the above purpose, the present invention provides the following technical solution: An aerobic granular sludge, characterized in that: the aerobic granular sludge is composed of the following components:

[0007] Basic sludge component group: aerobic granular sludge, nano-silicon, nano-magnetite oxide;

[0008] Functional strengthening component group: modified polymer, chitosan, carbon quantum dots;

[0009] Stability improvement component group: graphene, polylactic acid.

[0010] Preferably, the mixing ratio range of each component is as follows:

[0011] Basic sludge component group: Aerobic granular sludge: 40 - 60%, nano-silicon: 1 - 10%, nano-magnetite oxide: 0.5 - 7%;

[0012] Functional enhancement component group: Modified polymer: 1 - 8%, chitosan: 1 - 6%, carbon quantum dots: 0.1 - 5%;

[0013] Stability improvement component group: Graphene: 0.5 - 3%, polylactic acid: 1 - 5%.

[0014] Preferably, the mixing ratio range of the components is as follows:

[0015] Basic sludge component group: Aerobic granular sludge: 50 - 55%, nano-silicon: 3 - 7%, nano-magnetite oxide: 2 - 4%;

[0016] Functional enhancement component group: Modified polymer: 3 - 6%, chitosan: 3 - 5%, carbon quantum dots: 1 - 3%;

[0017] Stability improvement component group: Graphene: 1 - 2%, polylactic acid: 2 - 4%.

[0018] A method for culturing aerobic granular sludge, comprising the following steps:

[0019] S1. Raw material preparation:

[0020] S1.1. Weigh the raw materials of aerobic granular sludge, nano-silicon, nano-magnetite oxide, modified polymer, chitosan, carbon quantum dots, graphene, and polylactic acid, and control the mass tolerance of each raw material within ±0.1 g;

[0021] S1.2. Conduct particle size detection on the aerobic granular sludge. The specification requires that the particle size is between 15 - 30 microns, and the uniformity of the particle size distribution is controlled within ±2 microns;

[0022] S1.3. Detect the particle size and surface activity of nano-silicon and nano-magnetite oxide by a dynamic light scattering instrument, and control their particle size within 30 - 100 nm and the surface activity ≥80%;

[0023] S1.4. Store all the raw materials in an environment with a temperature of 25 ± 2°C and a humidity of 50 - 60%;

[0024] S2. Mixing treatment:

[0025] S2.1. Add the aerobic granular sludge, nano-silicon, and nano-magnetite oxide into the mixing equipment according to a predetermined ratio of 50:5:3, with a stirring speed of 200 - 300 revolutions per minute, and continuously stir for 15 - 20 minutes;

[0026] S2.2. Gradually add the modified polymer, chitosan, and carbon quantum dots, and continue stirring at a speed of 300 - 500 revolutions per minute for 10 - 15 minutes;

[0027] S2.3. Take a sample of the mixture and use a particle size analyzer to measure that the average particle size of the particles remains between 10 - 30 microns;

[0028] S3. Addition of functional strengthening components:

[0029] S3.1. Add graphene with a mass ratio of 1% - 3% and polylactic acid with a mass ratio of 2% - 4% to the mixture, and continue stirring at a speed of 300 - 500 revolutions per minute for 10 - 15 minutes;

[0030] S3.2. Observe regularly through an electron microscope until the dispersibility of graphene reaches more than 95% and there is no obvious aggregation phenomenon;

[0031] S3.3. Check the uniformity of the finished product mixture, requiring that the components are evenly distributed in the particles without stratification or sedimentation;

[0032] S4. Drying treatment:

[0033] S4.1. Transfer the mixture to a drying oven, set the temperature to 45 ± 2°C, control the humidity at ≤10%, conduct constant temperature drying for 2.5 hours to make the moisture content ≤4%;

[0034] S4.2. During the drying process, monitor the humidity in real time through an on - line humidity control system;

[0035] S5. Molding treatment:

[0036] S5.1. Mold the dried mixture through a molding press, with the molding pressure between 1.5 - 2.0 MPa and the size of the molded particles being 3 - 5 mm;

[0037] S5.2. After molding, conduct temperature control treatment, controlling the temperature between 35°C - 45°C;

[0038] S6. Screening and grading:

[0039] S6.1. Screen the molded particles through a sieve with a pore size of 3 mm to remove unqualified particles;

[0040] S6.2. Classify the particles through a particle classifier to make the particle size of each level uniform, with the error controlled within ±0.5 mm;

[0041] S7. Packaging and storage:

[0042] S7.1. Dispense the qualified particles through an automatic dispensing device at a weight of 50 grams ± 0.2 grams per bag, with the error controlled within ±0.2 grams.

[0043] S7.2. Use an aluminum foil bag for vacuum packaging.

[0044] S7.3. After packaging, store the product in an environment with a temperature of 25°C ± 2°C and a humidity not exceeding 50%.

[0045] Preferably, the S1 raw material preparation step further includes the following steps:

[0046] S1a. Store the aerobic granular sludge at 20 - 25°C and control the water content to be less than 5%.

[0047] S1b. Screen the particle sizes of nano-silicon, nano-magnetite oxide, and modified polymer respectively to ensure that their particle sizes are 50 - 100 nanometers, 30 - 50 nanometers, and 5 - 15 micrometers respectively, and the particle size distribution is uniform.

[0048] S1c. Conduct solubility tests on chitosan and carbon quantum dots, requiring their water solubility to be above 98%.

[0049] Preferably, the S2 mixing treatment step further includes the following steps:

[0050] S2a. Conduct low-speed premixing on the aerobic granular sludge, nano-silicon, and nano-magnetite oxide. The premixing time is 3 minutes and the speed is 150 revolutions per minute.

[0051] S2b. Gradually add the modified polymer, chitosan, and carbon quantum dots during the stirring process, increase the stirring speed to 350 - 500 revolutions per minute, and control the stirring time within 11 - 15 minutes.

[0052] Preferably, the S5 shaping treatment step further includes the following steps:

[0053] S5a. Press and shape through a hydraulic molding machine, and set the molding pressure to 1.6 - 1.9 MPa.

[0054] S5b. Immediately conduct temperature-controlled cooling after shaping, and control the temperature at 35°C - 40°C.

[0055] An application of aerobic granular sludge includes the following steps:

[0056] a) Put the aerobic granular sludge particles, and the putting standard is an addition amount of 20 - 30 grams per square meter of the reaction tank.

[0057] b) Start the aeration operation and adjust the aeration intensity to 0.5 - 1.5m 3 / min / 1000m 3, the aeration time is 24 hours, and the dissolved oxygen value in the pool is maintained within the range of 2 - 4 mg / L;

[0058] c) Regularly monitor the dissolved oxygen value of the reaction pool daily, and adjust the aeration intensity to make the DO value between 2.5 - 3.5 mg / L;

[0059] d) Conduct a check on the sedimentation performance of granular sludge monthly. Use a sedimentation tube and sedimentation experiment to evaluate that the sedimentation rate of granular sludge in water is not less than 10 cm / h;

[0060] e) Conduct water quality tests monthly, analyze the COD, BOD, nitrogen, and phosphorus indicators in the water, and verify whether the water quality meets the discharge standards: COD ≤ 50 mg / L, BOD ≤ 10 mg / L, nitrogen ≤ 5 mg / L, phosphorus ≤ 0.5 mg / L;

[0061] f) The treatment cycle is 3 months. Supplement aerobic granular sludge monthly as needed to maintain the stable operation of the system.

[0062] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0063] 1. By adding modified polymers and carbon quantum dot functional strengthening components, the dispersibility and stability of aerobic granular sludge are improved, avoiding the aggregation phenomenon of granular sludge, thereby effectively improving the water treatment efficiency.

[0064] 2. By combining graphene and polylactic acid stability improvement components, the biodegradation ability of granular sludge and its performance of resisting environmental changes are enhanced, improving the long-term stability and adaptability in the sewage treatment process.

[0065] 3. By optimizing the cultivation process, good performance of granular sludge in different water quality environments is achieved. Especially in the treatment of high-concentration organic sewage, the treatment effect is significantly improved compared with the traditional technology.

[0066] 4. By refining the particle size distribution and strict quality control, the best performance of granular sludge under different reaction conditions is achieved, ensuring its excellent sedimentation performance and stability in the water treatment process BRIEF DESCRIPTION OF THE DRAWINGS

[0067] Figure 1 is a schematic diagram of the components of the present invention;

[0068] Figure 2 is a schematic diagram of the component ratio range of the present invention;

[0069] Figure 3 is a flow chart of the cultivation method of the present invention;

[0070] Figure 4 is a schematic diagram of the application method of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0071] Next, in combination with the accompanying drawings in the embodiments of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present invention.

[0072] Please refer to Figures 1 to 4 , the present invention provides a technical solution: a novel aerobic granular sludge, comprising the following components: I. Composition of aerobic granular sludge

[0073] Basic sludge component group: aerobic granular sludge, nano-silicon, nano-magnetite oxide

[0074] Aerobic granular sludge: Aerobic granular sludge refers to sludge that has been treated by microorganisms and formed into granular form in an aerobic environment, usually composed of microorganisms and their decomposition products. It has a large specific surface area and can effectively adsorb and degrade organic pollutants in water. In the present invention, aerobic granular sludge is one of the basic components and is the main component during the cultivation process.

[0075] Nano-silicon: Nano-silicon is a nano-material with good chemical stability and a relatively high specific surface area. It can enhance the structural stability of aerobic granular sludge and improve the adsorption capacity of the sludge. The addition of nano-silicon can enhance the surface activity of sludge particles, which is beneficial to the contact and reaction between sludge particles and pollutants. It effectively guarantees its physical properties and ensures its dispersion in sludge particles.

[0076] Nano-magnetite oxide: Nano-magnetite oxide has strong magnetism, a small particle size, and a high surface energy. It can help the dispersion of granular sludge in water and its physicochemical stability. Through its magnetism, it can effectively enhance the flocculation and sedimentation ability of the sludge and accelerate the adsorption and degradation of organic pollutants in water.

[0077] Functional strengthening component group: modified polymer, chitosan, carbon quantum dots;

[0078] Modified polymer: A modified polymer is a polymer with good adhesion and enhanced mechanical properties, which can improve the toughness and stability of granular sludge. Through physical or chemical modification, it can form an effective cross-linked structure between sludge particles, improving the durability and functionality of the particles. The addition of a modified polymer can effectively optimize the rheological properties of sludge particles and improve their performance in water.

[0079] Chitosan: Chitosan is a natural polysaccharide with good biodegradability and excellent adsorption properties. It can adsorb organic substances and heavy metal ions in water. Chitosan can not only enhance the biodegradability of granular sludge but also improve its reactivity with harmful substances in sewage, thereby enhancing the water treatment efficiency. By adjusting its ratio, the adsorption and degradation properties of the granules can be adjusted according to different water quality conditions.

[0080] Carbon quantum dots: Carbon quantum dots are a new type of nanomaterial with unique optical and electrical properties. Carbon quantum dots can provide additional electron transfer channels in granular sludge and enhance its catalytic performance in water. They can promote the degradation of organic substances in sewage, especially some refractory organic pollutants. The addition of carbon quantum dots improves the reactivity of sludge particles and the water treatment rate.

[0081] Stability improvement component group: Graphene, polylactic acid;

[0082] Graphene: Graphene is a two-dimensional nanomaterial with excellent mechanical properties and high electrical conductivity. Its addition to sludge particles can significantly improve the stability and mechanical strength of the particles. The high specific surface area of graphene can provide more adsorption sites, further enhancing the adsorption of sludge particles. At the same time, graphene can also effectively enhance the dispersion of particles in water, avoiding particle aggregation and sedimentation.

[0083] Polylactic acid: Polylactic acid is a biodegradable polymer material with good film-forming properties and flexibility. In the present invention, the main role of polylactic acid is to increase the overall stability of granular sludge, avoiding uneven dispersion of particles in water. It can also provide appropriate biocompatibility, ensuring the stability of granular sludge during long-term use and enhancing its degradation effect on pollutants.

[0084] II. Ratio range of each component

[0085] Basic sludge component group: Aerobic granular sludge: 40 - 60%, nano-silicon: 1 - 10%, nano-magnetite oxide: 0.5 - 7%

[0086] Functional strengthening component group: Modified polymer: 1 - 8%, chitosan: 1 - 6%, carbon quantum dots: 0.1 - 5%

[0087] Stability improvement component group: Graphene: 0.5 - 3%, polylactic acid: 1 - 5%;

[0088] These ratios are the results of experimental optimization, which can ensure the stability, dispersion and degradability of sludge particles while improving the water treatment efficiency. Different ratios can adapt to different water treatment environments and pollutant types, providing flexible application solutions.

[0089] The aerobic granular sludge of the present invention fully exerts its advantages in the water treatment process through the combination of the above ratios and components. Specifically:

[0090] Particle formation and dispersion: Through the use of nano-silicon and nano-magnetite oxides during the cultivation process, more stable sites can be provided in water, ensuring the dispersion of granular sludge in water and improving its surface activity.

[0091] Adsorption and degradation: Chitosan and carbon quantum dots can form an effective adsorption layer on the surface of sludge particles, capture organic pollutants in water, and accelerate the degradation of pollutants through their catalytic action. Especially in sewage containing high concentrations of organic pollutants, the modified polymer and graphene further improve the durability and adsorption capacity of sludge particles.

[0092] Water quality improvement: During the application process, these granular sludges can remove pollutants such as COD, BOD, nitrogen, and phosphorus in water through oxidation reactions and adsorption, achieving the purpose of improving water quality.

[0093] The aerobic granular sludge provided by the present invention has multiple advantages: It not only improves the stability and dispersion of sludge particles, but also improves the efficiency of sewage treatment through the combination of various functional strengthening components, solves the limitations of traditional treatment methods in the treatment of high-concentration pollutants, and provides a new high-efficiency treatment material for the sewage treatment field.

[0094] The cultivation method of the aerobic granular sludge of the present invention ensures the stability, dispersion, and water treatment effect of the final product by precisely controlling the proportions of each component and the treatment steps. The following details each step of the cultivation process, including raw material preparation, mixing, addition of functional strengthening components, drying, shaping, screening, grading, packaging, and storage, etc.

[0095] S1. Raw material preparation

[0096] S1.1. Raw material weighing

[0097] In this step, first accurately weigh the raw materials of aerobic granular sludge, nano-silicon, nano-magnetite oxide, modified polymer, chitosan, carbon quantum dots, graphene, and polylactic acid, and control the mass tolerance of each raw material within ±0.1 grams. This is to ensure that the proportion of each component is accurately controlled during the cultivation process and to avoid affecting the performance of the final particles due to inaccurate raw material ratios.

[0098] S1.2. Particle size detection (aerobic granular sludge)

[0099] To ensure a uniform particle size distribution of aerobic granular sludge, its particle size is detected. The particle size is required to be controlled between 15 - 30 microns, and the uniformity of the particle size distribution needs to be controlled within ±2 microns. This is because the particle size has a direct impact on the dispersibility and adsorption performance of granular sludge, so the consistency of the particle size needs to be ensured.

[0100] S1.3, Particle Size and Surface Activity Detection of Nano - Silicon and Nano - Magnet Oxide

[0101] Nano - silicon and nano - magnet oxide have strong surface activity and good dispersibility. In this step, a dynamic light scattering instrument (DLS) is used to detect the particle size of these two materials. The particle size of nano - silicon is required to be controlled between 30 - 100 nanometers, and the particle size of nano - magnet oxide should also be maintained between 30 - 100 nanometers, and the surface activity of both is required to be ≥80%. This can ensure that the nanomaterials maintain good dispersibility during the mixing process and avoid aggregation.

[0102] S1.4, Raw Material Storage

[0103] All raw materials need to be stored in an environment with a temperature of 25 ± 2°C and a humidity of 50 - 60%. Maintaining appropriate temperature and humidity conditions can prevent the raw materials from absorbing moisture or deforming due to heat, ensuring that the performance of the raw materials is not affected.

[0104] S2, Mixing Treatment

[0105] S2.1, Mixing of Basic Components

[0106] In this stage, aerobic granular sludge, nano - silicon and nano - magnet oxide are added to the mixing equipment according to a predetermined ratio (50:5:3). The stirring speed is set at 200 - 300 revolutions per minute and stirred continuously for 15 - 20 minutes. The purpose of this mixing process is to make the three fully blend, ensuring that nano - silicon and nano - magnet oxide are evenly dispersed in aerobic granular sludge, thereby improving the stability of the particles and the water treatment performance.

[0107] S2.2, Adding Functional Strengthening Components

[0108] After that, modified polymer, chitosan and carbon quantum dots are gradually added and stirring continues. At this time, the stirring speed needs to be increased to 300 - 500 revolutions per minute, and the stirring time is controlled within 10 - 15 minutes. By increasing the stirring speed, it can better promote the uniform distribution of these functional materials in aerobic granular sludge and enhance the biodegradability and catalytic performance of the particles.

[0109] S2.3, Particle Size Detection

[0110] After mixing is completed, the mixture is sampled using a particle size analyzer to measure the average particle size. The goal is to ensure that the average particle size after mixing remains between 10 - 30 microns, which can optimize the particle dispersion and adsorption performance and improve the sewage treatment efficiency.

[0111] S3. Addition of functional strengthening components

[0112] S3.1. Addition of graphene and polylactic acid

[0113] In this step, graphene with a mass ratio of 1% - 3% and polylactic acid with a mass ratio of 2% - 4% are added to the mixture. Stirring continues at a speed of 300 - 500 revolutions per minute for 10 - 15 minutes. The addition of these two materials will further enhance the mechanical strength and water treatment performance of the particles.

[0114] S3.2. Inspection of graphene dispersion

[0115] The dispersion of the mixture is observed through an electron microscope to check the dispersion of graphene, ensuring that its dispersion reaches over 95% with no obvious aggregation. The good dispersion of graphene is crucial for maintaining the stability of the particles.

[0116] S3.3. Inspection of component uniformity

[0117] The uniformity of the final mixture is inspected to ensure that the components are evenly distributed in the particles without layering or sedimentation. An even distribution can ensure that the various properties of the particles are evenly exerted, improving its water treatment effect.

[0118] S4. Drying treatment

[0119] S4.1. Constant-temperature drying

[0120] The mixture is transferred to a drying oven for drying. The set temperature is 45 ± 2°C, and the humidity is controlled at ≤10%. The drying time is 2.5 hours until the moisture content drops to ≤4%. During this process, the humidity control system will monitor the humidity change in real time to ensure that the moisture content during drying is controlled within the ideal range, preventing over-drying or moisture residue.

[0121] S5. Molding treatment

[0122] S5.1. Compression molding

[0123] The dried mixture is pressed through a hydraulic molding machine. The molding pressure is set at 1.5 - 2.0 MPa, and the size of the molded particles is controlled between 3 - 5 mm. Appropriate molding pressure can ensure the compactness and stability of the particles.

[0124] S5.2. Temperature-controlled cooling

[0125] After forming, temperature control cooling is immediately carried out, and the temperature is controlled between 35°C and 45°C. This step helps to fix the structure of the particles and ensure that the particles do not deform or break during the cooling process.

[0126] S6. Screening and grading

[0127] S6.1 Screening

[0128] The formed particles are screened through a sieve with a pore size of 3 mm, and unqualified particles are removed to ensure that the size of the particles meets the requirements.

[0129] S6.2 Grading

[0130] The particles are graded by a particle grader to make the size of each grade of particles uniform, with the error controlled within ±0.5 mm. Grading helps to optimize the performance of the particles in practical applications and ensure that the particle size meets different sewage treatment requirements.

[0131] S7. Packaging and storage

[0132] S7.1 Sub-packaging

[0133] The qualified particles are sub-packed by an automatic sub-packaging device according to a weight of 50 g ± 0.2 g per bag, with the error controlled within ±0.2 g. Precise sub-packaging can ensure that the amount of particles in each package is consistent, facilitating subsequent transportation and use.

[0134] S7.2 Vacuum packaging

[0135] The particles are vacuum-packed using an aluminum foil bag to ensure that the particles are not affected by moisture and contamination during storage.

[0136] S7.3 Storage

[0137] After packaging, the product is stored in an environment with a temperature of 25°C ± 2°C and a humidity not exceeding 50%. Appropriate storage conditions can ensure the long-term stability of the particles and avoid affecting their performance due to environmental factors.

[0138] The aerobic granular sludge of the present invention can be widely applied to water treatment systems, especially in the fields of sewage treatment, wastewater treatment and environmental governance. By reasonably putting and managing the aerobic granular sludge, the water treatment efficiency can be significantly improved, the water quality can be improved, and the discharge standards can be met. The following details how to apply the aerobic granular sludge cultured by the present invention to the water treatment system.

[0139] a) Putting aerobic granular sludge

[0140] In the water treatment system, aerobic granular sludge particles are put into the reaction tank. The standard of the dosage depends on the volume of the reaction tank and the treatment requirements. Usually, the dosage per square meter of the reaction tank is 20 - 30 grams. Putting an appropriate amount of aerobic granular sludge can ensure the full effect of the granular sludge in water and give play to its good degradation and purification functions.

[0141] b) Start the aeration operation

[0142] After putting the aerobic granular sludge, start the aeration operation. Adjusting the aeration intensity is crucial for ensuring that the dissolved oxygen (DO) in water remains within an appropriate range. In specific operations, the aeration intensity needs to be adjusted to 0.5 - 1.5m 3 / min / 1000m 3 , and the aeration time is maintained for 24 hours. The key objective during the aeration process is to maintain the dissolved oxygen value in the tank between 2 - 4mg / L. This range of dissolved oxygen concentration helps the biodegradation of aerobic granular sludge and promotes the decomposition of organic matter in water.

[0143] c) Monitoring and adjustment of the dissolved oxygen value

[0144] To ensure the high efficiency of the water treatment process, the dissolved oxygen value in the reaction tank must be regularly monitored. Monitor the DO value of the reaction tank at least once a day, and adjust the aeration intensity according to the test results to ensure that the dissolved oxygen value always remains between 2.5 - 3.5mg / L. An appropriate dissolved oxygen concentration helps the microbial activity in the granular sludge and further improves the sewage treatment effect.

[0145] d) Inspection of the sedimentation property of granular sludge

[0146] Regularly inspecting the sedimentation property of aerobic granular sludge is a necessary measure to ensure the efficient operation of the system. Conduct a sedimentation property test of the granular sludge once a month, and use a sedimentation tube and sedimentation experiment to evaluate the sedimentation rate of the granular sludge in water. It is required that the sedimentation rate of the granular sludge is not less than 10cm / h. Granular sludge with good sedimentation property can quickly aggregate and settle to the bottom of the reaction tank, reducing the suspended solid content in the sewage and improving the clarity of the water.

[0147] e) Water quality detection

[0148] Monitoring the water quality is an important indicator for evaluating the sewage treatment effect. Conduct a water quality test once a month, mainly analyzing the chemical oxygen demand (COD), biochemical oxygen demand (BOD), nitrogen (N), and phosphorus (P) contents in the water. Judge whether the water quality meets the discharge standards through these indicators. The specific standards are: COD ≤ 50mg / L, BOD ≤ 10mg / L, nitrogen ≤ 5mg / L, phosphorus ≤ 0.5mg / L. When these indicators reach the standards, it proves that the purification effect of aerobic granular sludge on the water quality has been effectively exerted.

[0149] f) Regular supplementation of aerobic granular sludge

[0150] The treatment cycle is usually 3 months. To maintain the long-term stability and efficient operation of the water treatment system, aerobic granular sludge is supplemented monthly according to actual needs to ensure that the concentration and function of the granules in the reaction tank do not decrease due to consumption or sedimentation. Regular supplementation can ensure the activity of the granular sludge and maintain its excellent water treatment performance.

[0151] To better illustrate the specific applications and implementation effects of the present invention, the technical solutions of the present invention will be described in detail below through examples. The examples are only used to illustrate the technical ideas and implementation methods of the present invention and do not limit the protection scope of the present invention. Through the following examples, the advantages, operation steps, and effects of the aerobic granular sludge provided by the present invention in sewage treatment can be clearly understood.

[0152] Example 1: Application of aerobic granular sludge in a medium-sized sewage treatment plant

[0153] A medium-sized sewage treatment plant was selected for this experiment. The water sources to be treated were mainly industrial wastewater and domestic sewage, which contained a relatively high concentration of organic matter (COD value of 200 - 300 mg / L), as well as certain amounts of pollutants such as nitrogen and phosphorus. According to the water quality characteristics of this plant, the aerobic granular sludge provided by the present invention was used for the water treatment experiment, and a comparison was made with the traditional activated sludge method to evaluate its application effect under actual operating conditions.

[0154] Implementation method

[0155] According to the application scheme of the present invention, the specific implementation steps are as follows:

[0156] a) Feeding aerobic granular sludge: Feed aerobic granular sludge according to the area and volume of the reaction tank.

[0157] b) Starting aeration operation: Adjust the aeration intensity to 0.8 m 3 / min / 1000 m 3 , and set the aeration time to 24 hours to ensure that the dissolved oxygen value in the tank is stable at 3.0 mg / L.

[0158] c) Dissolved oxygen monitoring and adjustment: Regularly monitor the dissolved oxygen value of the reaction tank every day, and adjust the aeration intensity according to the data to ensure that the dissolved oxygen is maintained between 2.5 - 3.5 mg / L.

[0159] d) Sedimentation inspection: Conduct a granular sludge sedimentation experiment every month to ensure that the sedimentation rate is not lower than 10 cm / h.

[0160] e) Water quality detection: Regularly detect indicators such as COD, BOD, nitrogen, and phosphorus in the water every month to ensure that the water quality meets the environmental protection discharge standards.

[0161] f) Regularly supplement aerobic granular sludge: The treatment cycle is 3 months, and a certain amount of aerobic granular sludge is supplemented every month to ensure the stable operation of the system.

[0162] Experimental results

[0163]

[0164]

[0165] Comparative experimental results

[0166] COD and BOD removal effects: During the treatment process of the aerobic granular sludge of the present invention, the removal efficiencies of COD and BOD are significantly higher than those of the traditional activated sludge process. The traditional activated sludge process has low efficiency in treating high-concentration organic wastewater, while the aerobic granular sludge of the present invention can degrade the organic matter in water in a shorter time, especially in the case of higher concentrations, showing stronger degradation ability.

[0167] Nitrogen and phosphorus removal effects: In terms of nitrogen and phosphorus removal, the aerobic granular sludge of the present invention is also superior to the traditional method. Through precise dosing of granular sludge and aeration operation, it can more effectively promote the removal of nitrogen and phosphorus in water, meeting the environmental protection discharge standards.

[0168] Sedimentation property of granular sludge: The aerobic granular sludge of the present invention has excellent sedimentation property, and the sedimentation rate is above 10 cm / h, while the sedimentation rate of the traditional activated sludge is slower and it is prone to poor flocculation.

[0169] Dissolved oxygen control: The present invention can precisely regulate the dissolved oxygen (DO) value in the reaction tank to maintain it within the optimal range, thereby improving the degradation efficiency of microorganisms and ensuring the high efficiency of sewage treatment.

[0170] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principle and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An aerobic granular sludge, characterized in that: The aerobic granular sludge is composed of the following components: Basic sludge component group: aerobic granular sludge, nano-silicon, nano-magnetite oxide; Functional strengthening component group: modified polymer, chitosan, carbon quantum dots; Stability improvement component group: graphene, polylactic acid.

2. The aerobic granular sludge according to claim 1, wherein: The mixing ratio ranges of the above components are as follows: Basic sludge component group: aerobic granular sludge: 40 - 60%, nano-silicon: 1 - 10%, nano-magnetite oxide: 0.5 - 7%; Functional strengthening component group: modified polymer: 1 - 8%, chitosan: 1 - 6%, carbon quantum dots: 0.1 - 5%; Stability improvement component group: graphene: 0.5 - 3%, polylactic acid: 1 - 5%.

3. An aerobic granular sludge according to claim 2, characterized in that: The mixing ratio ranges of the components are as follows: Basic sludge component group: aerobic granular sludge: 50 - 55%, nano-silicon: 3 - 7%, nano-magnetite oxide: 2 - 4%; Functional strengthening component group: modified polymer: 3 - 6%, chitosan: 3 - 5%, carbon quantum dots: 1 - 3%; Stability improvement component group: graphene: 1 - 2%, polylactic acid: 2 - 4%.

4. A method for culturing aerobic granular sludge, applied to the aerobic granular sludge according to any one of claims 1-3, characterized in that: It includes the following steps: S1. Raw material preparation: S1.

1. Weigh the raw materials of aerobic granular sludge, nano-silicon, nano-magnetite oxide, modified polymer, chitosan, carbon quantum dots, graphene, and polylactic acid, and control the mass tolerance of each raw material within ±0.1 g; S1.

2. Conduct particle size detection on the aerobic granular sludge. The specification requires that the particle size is between 15 - 30 μm, and the uniformity of the particle size distribution is controlled within ±2 μm; S1.

3. Detect the particle size and surface activity of nano-silicon and nano-magnetite oxide by a dynamic light scattering instrument, and control their particle size within 30 - 100 nm and surface activity ≥80%; S1.

4. Store all the raw materials in an environment with a temperature of 25 ± 2°C and a humidity of 50 - 60%; S2. Mixing treatment: S2.

1. Add aerobic granular sludge, nano-silicon, and nano-magnetite oxide into the mixing equipment according to the predetermined ratio of 50:5:3, with a stirring speed of 200 - 300 revolutions per minute, and continuously stir for 15 - 20 minutes; S2.

2. Gradually add the modified polymer, chitosan, and carbon quantum dots, and continue stirring. The stirring speed is 300 - 500 revolutions per minute, and the stirring time is 10 - 15 minutes; S2.

3. Take a sample of the mixture and use a particle size analyzer to measure that the average particle size of the particles remains between 10 - 30 μm; S3. Addition of functional strengthening components: S3.

1. Add graphene with a mass ratio of 1% - 3% and polylactic acid with a mass ratio of 2% - 4% into the mixture, and continue to stir at a speed of 300 - 500 revolutions per minute for 10 - 15 minutes; S3.

2. Observe regularly through an electron microscope until the dispersibility of graphene reaches more than 95% and there is no obvious aggregation phenomenon; S3.

3. Check the uniformity of the finished product mixture, and require that the components are evenly distributed in the particles without stratification or sedimentation; S4. Drying treatment: S4.

1. Transfer the mixture to a drying oven, set the temperature to 45 ± 2°C, control the humidity ≤10%, conduct constant temperature drying, and the drying time is 2.5 hours to make the moisture content ≤4%; S4.

2. During the drying process, the humidity is monitored in real time by an on-line humidity control system; S5. Molding process: S5.

1. The dried mixture is molded by a pressing machine, with the molding pressure between 1.5 - 2.0 MPa and the size of the molded particles being 3 - 5 mm; S5.

2. After molding, temperature control treatment is carried out, with the temperature controlled between 35°C - 45°C; S6. Screening and grading: S6.

1. The molded particles are screened through a sieve with a pore size of 3 mm to remove unqualified particles; S6.

2. The particles are graded by a particle grader to make the size of each grade of particles uniform, with the error controlled within ±0.5 mm; S7. Packaging and storage: S7.

1. The qualified particles are packaged automatically by a packaging device at a weight of 50 g ± 0.2 g per bag, with the error controlled within ±0.2 g; S7.

2. Vacuum packaging is carried out using an aluminum foil bag; S7.

3. After packaging is completed, the product is stored in an environment with a temperature of 25°C ± 2°C and a humidity not exceeding 50%.

5. The culturing method of aerobic granular sludge according to claim 4, characterized in that: The raw material preparation step of S1 also includes the following steps: S1a. The aerobic granular sludge is stored at 20 - 25°C, and the water content is controlled below 5%; S1b. The particle sizes of nano-silicon, nano-magnetite oxide, and modified polymer are screened respectively to ensure that their particle sizes are 50 - 100 nm, 30 - 50 nm, and 5 - 15 μm respectively, and the particle size distribution is uniform; S1c. The solubility of chitosan and carbon quantum dots is detected, and their water solubility is required to be above 98%.

6. The culturing method of aerobic granular sludge according to claim 4, characterized in that: The mixing treatment step of S2 also includes the following steps: S2a. The aerobic granular sludge, nano-silicon, and nano-magnetite oxide are pre-mixed at a low speed for 3 minutes at a speed of 150 revolutions per minute; S2b. During the stirring process, the modified polymer, chitosan, and carbon quantum dots are gradually added, and the stirring speed is increased to 350 - 500 revolutions per minute, with the stirring time controlled within 11 - 15 minutes.

7. The cultivation method of aerobic granular sludge according to claim 4, characterized in that: The molding treatment step of S5 also includes the following steps: S5a. Pressing and molding are carried out by a hydraulic molding machine, with the molding pressure set at 1.6 - 1.9 MPa; S5b. Temperature control cooling is carried out immediately after molding, with the temperature controlled between 35°C - 40°C.

8. Application of aerobic granular sludge, characterized in that: The aerobic granular sludge particles obtained by using the cultivation method of aerobic granular sludge according to any one of claims 4 - 7 are applied to a water treatment system, including the following steps: a) The aerobic granular sludge particles are put in, and the putting standard is that the addition amount per square meter of the reaction tank is 20 - 30 g; b) Start the aeration operation and adjust the aeration intensity to 0.5 - 1.5 m 3 / min / 1000 m 3 , with an aeration time of 24 hours and maintaining the dissolved oxygen value in the pool within the range of 2 - 4 mg / L; c) The dissolved oxygen value of the reaction tank is monitored regularly every day, and the aeration intensity is adjusted to make the DO value between 2.5 - 3.5 mg / L; d) The sedimentation property of the granular sludge is checked monthly, and a sedimentation tube and sedimentation experiment are used to evaluate that the sedimentation speed of the granular sludge in water is not less than 10 cm / h; e) Water quality detection is carried out monthly, and the COD, BOD, nitrogen, and phosphorus indexes in the water are analyzed to verify whether the water quality meets the discharge standards: COD ≤ 50 mg / L, BOD ≤ 10 mg / L, nitrogen ≤ 5 mg / L, phosphorus ≤ 0.5 mg / L; f) The treatment cycle is 3 months. Aerobic granular sludge is supplemented monthly as needed to maintain the stable operation of the system.

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