Sewage treatment process based on aerobic granular sludge
By employing an intelligent cycle adjustment method based on a granular sludge lifecycle model, the system instability problem of aerobic granular sludge process under influent load shock and mass transfer limitation was solved. This method enabled accurate identification and dynamic control of granular sludge, improving the system's adaptability and stability.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- NANJING BEIDE ENVIRONMENTAL PROTECTION EQUIP MFG
- Filing Date
- 2025-12-31
- Publication Date
- 2026-05-05
AI Technical Summary
Existing aerobic granular sludge processes lack refined management and are susceptible to influent load shocks, dissolved oxygen changes, and internal mass transfer limitations, leading to abnormally large particle sizes, decreased settling performance, or loose sludge structure, resulting in system instability or even particle disintegration.
An intelligent cycle adjustment method based on the granular sludge life cycle model is adopted. By collecting parameters such as particle size, settling ratio, density and redox potential of granular sludge, the life cycle index (LCI) is calculated. The aeration time, settling time and sludge discharge ratio are dynamically adjusted according to different life cycle stages. Combined with a multi-index cross-judgment mechanism, the precise identification and dynamic control of granular sludge can be achieved.
It improves the adaptability and stability of system operation, avoids large-scale particle disintegration, maintains compact particle structure and high microbial activity, and is suitable for industrial wastewater treatment scenarios with large fluctuations in water quality load.
Smart Images
Figure CN121974483A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the technical field of wastewater treatment, and more particularly to a wastewater treatment process based on aerobic granular sludge. Background Technology
[0002] Aerobic granular sludge technology, as a rapidly developing new biological wastewater treatment process in recent years, has advantages such as excellent settling performance, high microbial concentration, strong shock resistance, and small footprint. Currently, most common aerobic granular sludge processes are based on sequencing batch reactors (SBRs), which use a cyclical operation mode of "influent-aeration-sedimentation-effluent" to form a dense granular structure of sludge under high selective pressure.
[0003] Existing granular sludge operation control relies heavily on experience-based adjustments, such as manual intervention based on sludge concentration, effluent quality, or cyclical operation results. This lack of refined management of the growth, maturation, expansion, aging, and disintegration patterns of granular sludge is problematic. Especially in practical engineering, granular sludge is susceptible to factors such as influent load fluctuations, dissolved oxygen changes, and internal mass transfer limitations, leading to abnormally large particle sizes, decreased settling performance, or loose sludge structure, thereby causing system instability or even complete particle disintegration. Summary of the Invention
[0004] The purpose of this section is to outline some aspects of embodiments of the present invention and to briefly describe some preferred embodiments. Simplifications or omissions may be made in this section, as well as in the abstract and title of this application, to avoid obscuring the purpose of these documents; however, such simplifications or omissions should not be construed as limiting the scope of the invention.
[0005] To solve the above-mentioned technical problems, the present invention provides the following technical solution: In a first aspect, the present invention provides a wastewater treatment process based on aerobic granular sludge, comprising: S1. Introduce the wastewater to be treated into the reaction tank so that the wastewater comes into contact with the aerobic granular sludge in the reaction tank. S2. Aeration is carried out in the reaction tank to form an aerobic zone on the outer layer of the granular sludge and an anoxic zone on the inner layer, so as to achieve the degradation of organic matter and the removal of nitrogen and phosphorus. S3. Stop aeration to allow granular sludge with good settling properties to settle quickly and separate from flocculent sludge. S4. Discharge the supernatant from the reaction tank and retain the granular sludge; S5. Discharge aged sludge and replenish newly generated activated sludge according to the system operating load and adjust the influent volume. S6. Intelligent cycle adjustment based on granular sludge life cycle model, the specific steps are as follows: S6.1. Collect relevant operating parameters; S6.2 Calculate the life cycle index (LCI) of granular sludge; S6.3. Dynamically adjust the aeration time, sedimentation time, and sludge discharge ratio of the SBR according to the life cycle stage.
[0006] As a preferred embodiment of the wastewater treatment process based on aerobic granular sludge described in this invention, the calculation of the Life Cycle Index (LCI) is as follows: ; in: , , These are the weighting coefficients; , , These are the real-time particle size, settling ratio, and density of granular sludge; , , These are the reference values for particle size, sedimentation ratio, and density at the particle maturity stage, respectively.
[0007] As a preferred embodiment of the wastewater treatment process based on aerobic granular sludge described in this invention, the life cycle model is set with different life cycle stages based on LCI, including: Growth stage: LCI < first threshold T1; Maturity stage: T1≤LCI≤Second thresholdT2; During the aging stage, LCI ≥ T2.
[0008] In a preferred embodiment of the wastewater treatment process based on aerobic granular sludge described in this invention, the determination of the life cycle stage is further combined with one or more of the following cross-determinations: When particle size Larger than the set maximum particle size Furthermore, when the particle density decreases by more than a preset percentage, it is strongly determined to be in the aging stage; When the sedimentation ratio Below the settling ratio performance threshold Shi Qiang is judged to be in the mature stage; When the particle volume ratio The growth rate exceeded the set value At that time, it is determined to be in the growth stage.
[0009] As a preferred embodiment of the wastewater treatment process based on aerobic granular sludge described in this invention, when the life cycle stage is in the growth stage, the following cycle adjustment strategy is implemented: Increase aeration time by 10%-25% to enhance shear force; Settling time is shortened by 10%-20% to enhance selective pressure; Increase the drainage volume appropriately to improve particle enrichment efficiency.
[0010] As a preferred embodiment of the wastewater treatment process based on aerobic granular sludge described in this invention, when the life cycle stage is in the mature stage, the following cycle adjustment strategy is implemented: Maintain the aeration time at the set optimal value. ; Settling is performed according to the set set set time to maintain the particle structure; Maintain normal carbon source input levels without adding additional selection pressure.
[0011] As a preferred embodiment of the wastewater treatment process based on aerobic granular sludge described in this invention, when the life cycle stage is in the aging stage, the following periodic adjustment strategy is implemented: Reduce aeration time by 10%–20% to prevent further particle breakage; Increasing the settling time by 5%–15% enhances the identification of sedimentation of aged particles; Increase the sludge discharge ratio to remove aged particulate sludge; Appropriately increase the carbon source concentration in the influent to promote the formation of new particles.
[0012] As a preferred embodiment of the wastewater treatment process based on aerobic granular sludge described in this invention, wherein: based on the difference between the current life cycle index and the life cycle index of the previous cycle... The strategy is adjusted as follows: when Less than the preset threshold Maintain the current strategy; when Less than Enhance growth stage adjustment strategies; when Greater than Strengthen aging stage adjustment strategies.
[0013] As a preferred embodiment of the wastewater treatment process based on aerobic granular sludge described in this invention, the process further includes the activation of an abnormal recovery cycle, the specific triggering conditions for the activation of the abnormal recovery cycle being as follows: Particle size Exceeding the maximum allowable particle size ; Settlement ratio A significant increase leads to a worse settlement ratio; The abnormal fluctuations in the redox potential (ORP) were detected, indicating cavitation inside the particles. During the abnormal recovery cycle, the system reduces aeration time, increases sludge discharge ratio, extends sedimentation time, and reduces influent load.
[0014] Secondly, the present invention also provides an intelligent wastewater treatment control system, comprising: Granular sludge parameter acquisition module, used to acquire... , Particle parameters such as ρ, VR, and ORP; The life cycle model calculation module is used to calculate LCI and determine the stage of the particle life cycle; The cycle adjustment module is used to automatically adjust the aeration time, sedimentation time, sludge discharge ratio and carbon source addition according to the life cycle stage. An abnormal state handling module is used to execute recovery strategies when the particle state is abnormal; The control and execution unit is used to send execution commands to the aeration system, sludge removal system, and dosing system. The beneficial effects of this invention are: 1. This invention introduces an aerobic granular sludge lifecycle model and combines it with multiple indicators such as particle size, settling performance, and redox potential to construct an intelligent cycle adjustment algorithm, achieving precise identification and dynamic control of the operating status of aerobic granular sludge. Compared with existing experience-based traditional control methods, this invention can automatically adjust the operating cycle parameters according to the different lifecycle stages of the particles, thereby improving the adaptability and stability of the system operation.
[0015] 2. This invention utilizes a multi-indicator cross-judgment mechanism to identify structural instability signs such as particle swelling, deterioration of settling properties, and abnormal mass transfer within particles in advance. It initiates a targeted recovery cycle before these anomalies occur, effectively preventing large-scale particle disintegration and improving the long-term stability of the particle population. Simultaneously, this invention maintains a compact particle structure and highly efficient microbial activity through precise control, resulting in stable effluent quality and strong shock resistance, making it particularly suitable for industrial wastewater treatment scenarios with significant fluctuations in water quality load. Attached Figure Description
[0016] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Wherein: Figure 1 This is a process flow diagram of a wastewater treatment process based on aerobic granular sludge proposed in this invention. Figure 2This is a flow chart of S6 in a wastewater treatment process based on aerobic granular sludge proposed in this invention. Figure 3 This is a system architecture diagram of the intelligent wastewater treatment and control system proposed in this invention. Detailed Implementation
[0017] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.
[0018] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.
[0019] Reference Figure 1-3 This invention provides a wastewater treatment process based on aerobic granular sludge, comprising: S1. Introduce the wastewater to be treated into the reaction tank so that the wastewater comes into contact with the aerobic granular sludge in the reaction tank. S2. Aeration is carried out in the reaction tank to form an aerobic zone on the outer layer of the granular sludge and an anoxic zone on the inner layer, so as to achieve the degradation of organic matter and the removal of nitrogen and phosphorus. S3. Stop aeration to allow granular sludge with good settling properties to settle quickly and separate from flocculent sludge. S4. Discharge the supernatant from the reaction tank and retain the granular sludge; S5. Discharge aged sludge and replenish newly generated activated sludge according to the system operating load and adjust the influent volume. S6. Intelligent cycle adjustment based on granular sludge life cycle model, the specific steps are as follows: S6.1 Collect relevant operating parameters, including granular sludge particle size D and settling ratio SVI. 30 Particle density ρ, particle volume ratio VR, redox potential ORP, etc. S6.2 Calculate the life cycle index (LCI) of granular sludge; The Life Cycle Index (LCI) is calculated as follows: ; in: , , These are the weighting coefficients; , , These are the real-time particle size, settling ratio, and density of granular sludge; , , These are the reference values for particle size, sedimentation ratio, and density at the particle maturity stage. Determining the particle life cycle requires a comprehensive assessment of the particle state from three dimensions: particle size (reflecting particle robustness and determining maturity or decay), sedimentation ratio (reflecting particle compactness and dispersion, closely related to sedimentation stage duration and stability), and density (reflecting the uniformity and maturity of the particle's internal structure, determining its shear resistance and activity distribution). These three characterization indicators are normalized and combined to form a quantifiable "particle health" index. Used to determine whether the structure has reached the mature particle size; as particles mature, the particle size... It will approach the reference value of mature particles. ,like This indicates that the stage is still in the growth phase, and the cycle should be extended to promote maturity. This indicates that the particle structure may have entered an oversized or hollowed-out stage, requiring adjustment of the operating load. This ratio is used to describe the maturity of the particle structure. Used to reflect whether settling performance is optimal, during the particle maturation stage. Significant decrease (rapid settling), when Close to reference value This indicates that the shape is firm and stable, when A gradual increase indicates problems such as disintegration and proliferation of filamentous bacteria. This ratio is used to reflect whether the particles have entered the decline phase. Used to reflect the health of the internal structure, an increase in density indicates that the particles are maturing and EPS is increasing, while a decrease in density indicates that the particles are becoming hollow, the internal gaps are increasing, and they are entering the decline stage. This ratio can directly reflect the internal vitality of the particles. By summing the standardized values in a linear weighted manner, it can reflect in real time whether the particles are in the optimal life cycle stage. Using the life cycle index as the input for cycle control can achieve fully automatic cycle adaptive adjustment. S6.3. Dynamically adjust the aeration time, sedimentation time and sludge discharge ratio of the SBR according to the life cycle stage; The lifecycle model is based on LCI and sets different lifecycle stages, including: Growth stage: LCI < first threshold T1; Maturity stage: T1≤LCI≤Second thresholdT2; During the aging stage, LCI ≥ T2; By dividing the sludge into stages using LCI (Liquidity Index), a management mechanism similar to a "health index" is formed, changing the state of sludge from "fuzzy judgment" to "visual judgment." Different adjustment strategies are corresponding to different stages. This staged control method gives the periodic adjustment a clear logical basis and avoids particle damage caused by disordered adjustment. At the same time, by identifying the stages, protective measures can be taken in advance during the aging stage to prevent the particles from being further damaged under high shear force, reduce SVI mutation phenomenon, and extend particle life. The determination of the lifecycle stage also involves a cross-determination of one or more of the following: When particle size Larger than the set maximum particle size Furthermore, when the particle density decreases by more than a preset ratio, it is strongly judged to be in the aging stage; there are two typical characteristics of granular sludge aging: excessively large particle size and gradual hollowing, and a decrease in internal density; when these two indicators appear at the same time, even if the LCI has not completely decreased, it should be judged to be aging immediately. When the sedimentation ratio Below the settling ratio performance threshold The settling strength (SVI) indicates the maturity stage. Mature particles exhibit significant characteristics: high density, compact structure, and excellent settling performance. SVI is the most sensitive and direct criterion for maturity; therefore, when SVI is below the threshold (indicating very good settling), it should be quickly determined to be in the maturity stage, even if the particle size has not yet reached the required level. The density also varies slightly; When the particle volume ratio The growth rate exceeded the set value When the growth stage is reached, the early stage of particle formation is characterized by rapid EPS synthesis, rapid volume increase, and primary agglomeration into granular state. At this time, the volume change (VR) is much more sensitive than the particle size change. Therefore, the volume growth rate is an excellent "early maturity signal". Although LCI can comprehensively reflect the particle state, some indicators lag in actual engineering (such as density changes often lag behind particle size changes, SVI is greatly affected by operational disturbances and may sometimes be abnormal temporarily, and the value of the life cycle index may not be sensitive enough when the particle size increases significantly). Therefore, using LCI alone may lead to occasional misjudgments or insufficient timely response to certain "dangerous states". When the life cycle is in the growth phase, the following cycle adjustment strategy is implemented: Aeration time is increased by 10%–25% to enhance shear force. During the growth period, the particle structure is loose, requiring higher shear force to promote: the shedding of loose flocs, the re-aggregation of microorganisms, increased EPS (extracellular polymeric substances) synthesis, and a denser particle surface. The turbulence and microscale shear force brought about by increased aeration are conducive to the formation of more uniform particles, denser particles, and a more stable surface structure. However, excessive shear force may lead to biomass loss. Therefore, limiting it to the 10%–25% range is the optimal compromise within the controllable range of engineering. The settling time is shortened by 10%-20% to enhance selective pressure. Shortening the settling time will bring two "natural selection" effects: slow-settling, flocculent, and lightweight sludge will be washed away, while fast-settling, high-density particles will be retained. This is one of the core mechanisms for the formation of granular sludge. Too much reduction in settling time will lead to a large loss of biomass. Therefore, 10%-20% is selected as the optimal range for the project. Appropriately increasing the drainage volume can improve particle enrichment efficiency. During the growth period, the system aims to increase the relative content of particles in the system as quickly as possible, allowing well-settled particles to become the "mainstream biological community." After appropriately increasing the drainage volume, the renewal cycle is accelerated, selective pressure is enhanced, and flocculent sludge is discharged more quickly. Excessive drainage volume may cause particle loss, so this strategy is usually automatically fine-tuned by the system based on real-time LCI, rather than a fixed value. The growth stage of aerobic granular sludge typically has the following characteristics: the granules are still in the aggregation and initial granulation stage, containing more filamentous bacteria and flocculent sludge, with a loose structure, low density, and unstable settling performance; therefore, the system needs to apply appropriate selective pressure and shear force to: promote the shedding of flocculent sludge, retain granules with better settling performance, and accelerate the granulation process. When the lifecycle stage is in the mature stage, the following cycle adjustment strategy is implemented: Maintain the aeration time at the set optimal value. ; Settling is performed according to the set set set time to maintain the particle structure; Maintain normal carbon source input levels without increasing selection pressure; At this stage, granular sludge has entered the equilibrium zone of "structural stability - optimal performance". Any over-adjustment may disrupt this equilibrium. Therefore, it is proposed to adopt a stability maintenance strategy in the mature stage to ensure that granular sludge maintains the optimal structure in the long term. When the lifecycle stage is in the aging stage, the following periodic adjustment strategy is implemented: Reduce aeration time by 10%–20% to prevent further particle breakage. Reducing aeration will: directly reduce water shear force, slow down the internal structural damage caused by excessive DO infiltration, prevent the outer layer of particles from being excessively impacted and falling off, ensure that aged particles can maintain an "identifiable" particle state, and provide conditions for subsequent sludge discharge. Increasing the settling time by 5%–15% enhances the identification of aging particles during settling. Aging particles have a lower density and a looser internal structure, and their settling speed is significantly lower than that of mature particles. Therefore, it is necessary to appropriately increase the settling time. Extending the settling time can form more obvious stratification, which facilitates precise sludge discharge and improves solid-liquid separation efficiency. Increasing the sludge discharge ratio removes aged granular sludge; it can systematically remove low-density, loosely structured aged particles, making room for the formation of new particles, adjusting the particle size distribution, restoring the system to a state where "healthy particles dominate", preventing excessive accumulation of aged particles from causing the system to "flocculate", ensuring stable particle size distribution, maintaining the desired settling performance, and maintaining the overall treatment capacity of granular sludge for a long time. Appropriately increase the carbon source concentration in the influent to promote the formation of new particles; shorten the time for new particles to replace aging particles, maintain the stability of the system's treatment capacity, and prevent the system from "deactivating" due to excessive aging particles. Granular sludge enters the "aging stage" in the later stages of its life cycle. At this time, granular sludge typically exhibits the following characteristics: loose internal structure of particles, EPS degradation, decreased microbial activity, low carbon source utilization, decreased particle density leading to floating and breakage, formation of internal cavities, easy splitting under aeration impact, and easy destruction by shear force, resulting in loss of settling ability. If not adjusted in time, aged particles will quickly break into small particles or flocculent sludge, which will seriously affect: effluent water quality stability, overall particle size distribution of granular sludge, and overall reactor stability. Therefore, this invention proposes the above four combined strategies for the aging stage to inhibit aging, promote renewal, and maintain system stability. Based on the difference between the current life cycle index and the life cycle index of the previous period (in This is the current life cycle index. The strategy will be adjusted based on the life cycle index of the previous cycle. The specific strategy adjustments are as follows: when Less than the preset threshold Maintain the current strategy; when Less than Enhance growth stage adjustment strategies; when Greater than Enhanced aging stage adjustment strategies; The ΔLCI represents the trend of granular sludge change in this cycle compared to the previous cycle: ΔLCI>0 → deterioration trend (aging progress), ΔLCI<0 → development towards health (growth or recovery), ΔLCI close to 0 → system stability and small changes. This is a threshold used to filter small fluctuations (noise) in granular sludge, preventing the system from frequently adjusting its operating strategy due to minor fluctuations; when the fluctuation is below the threshold... This indicates that the changes in the state of granular sludge are within the normal fluctuation range and do not represent a trend change; a significantly negative ΔLCI value means that: the particle size growth rate is increased, settling properties are improved, EPS generation is increased, and microbial activity is enhanced. Strengthening the growth stage adjustment strategy can further enhance the granulation process, accelerate the transformation of small particles into mature particles, and allow the system to enter the stable maturity zone more quickly during the healthy development stage; when Greater than This indicates EPS degradation, decreased settling velocity, disordered DO gradient, uneven particle size, or the onset of cavitation; it also indicates that granular sludge is clearly entering an aging trend; strengthening the adjustment strategy during the aging stage can curb the further deepening of aging, maintain the overall particle size distribution stability, and avoid a large number of particles suddenly breaking down, which would lead to effluent deterioration. The process also includes enabling an anomaly recovery cycle, and the specific triggering conditions for enabling the anomaly recovery cycle are as follows: Particle size Exceeding the maximum allowable particle size Excessively large particles (e.g., diameter > 1.5–2.0 mm) are prone to internal problems such as expansion of anoxic and anaerobic zones, restricted nutrient diffusion, internal cavitation or shedding, and loose particle structure and disintegration. Therefore, a quantifiable maximum allowable particle size needs to be set. ; Settlement ratio A significant increase leads to a worsening of the settling ratio; particle disintegration causing an increase in SVI is usually the earliest signal before instability, therefore The 30-minute sludge volume index directly reflects the settling properties of granular sludge, with a specific index showing a significant increase being set as follows: For three consecutive monitoring periods (e.g., every 4 hours), the value is more than 25% higher than the baseline value or If the concentration is >80 mL / g, the sedimentation is considered to have deteriorated, and a recovery cycle needs to be initiated. The monitoring of continuous abnormal fluctuations in oxidation-reduction potential (ORP) indicates cavitation inside the granules. The oxidation-reduction state inside healthy granular sludge is stable, and the ORP generally fluctuates little during the aeration stage. When there is hypoxia in the center of the granules, internal disintegration, or changes in granule density, continuous abnormal fluctuations in ORP will occur. The definition of continuous abnormal fluctuations is that the 5-minute sliding standard deviation of ORP meets the following condition: Std(ORP5min)>45 mV and the duration exceeds 30 minutes. During the abnormal recovery period, the system reduces aeration time (to alleviate the internal oxidation pressure of the particles and prevent further cavitation and disintegration), increases the sludge discharge ratio (to remove low-quality particles and retain highly active particle groups), extends the settling time (to encourage the preferential retention of high-density particles and remove loose particles), and reduces the influent load (to avoid particle breakage caused by high load and reduce nutrient pressure).
[0020] This embodiment also provides an intelligent wastewater treatment control system, including: Granular sludge parameter acquisition module, used to acquire... , Particle parameters such as ρ, VR, and ORP; The life cycle model calculation module is used to calculate LCI and determine the stage of the particle life cycle; The cycle adjustment module is used to automatically adjust the aeration time, sedimentation time, sludge discharge ratio and carbon source addition according to the life cycle stage. An abnormal state handling module is used to execute recovery strategies when the particle state is abnormal; The control and execution unit is used to send execution commands to the aeration system, sludge discharge system, and dosing system.
[0021] In summary, this invention introduces an aerobic granular sludge lifecycle model and constructs an intelligent cycle adjustment algorithm based on multiple indicators such as particle size, settling performance, and redox potential, achieving precise identification and dynamic control of the operational status of aerobic granular sludge. Simultaneously, through a multi-indicator cross-judgment mechanism, this invention can identify structural instability signs such as particle expansion, deterioration of settling properties, and abnormal mass transfer within particles in advance, and initiate targeted recovery cycles before these anomalies occur, effectively preventing large-scale particle disintegration and improving the long-term stability of the particle population. Furthermore, this invention maintains a compact particle structure and high microbial activity through refined control, resulting in stable effluent quality and strong shock resistance, making it particularly suitable for industrial wastewater treatment scenarios with large fluctuations in water quality load.
[0022] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.
Claims
1. A wastewater treatment process based on aerobic granular sludge, characterized in that: include: S1. Introduce the wastewater to be treated into the reaction tank so that the wastewater comes into contact with the aerobic granular sludge in the reaction tank. S2. Aeration is carried out in the reaction tank to form an aerobic zone on the outer layer of the granular sludge and an anoxic zone on the inner layer, so as to achieve the degradation of organic matter and the removal of nitrogen and phosphorus. S3. Stop aeration to allow granular sludge with good settling properties to settle quickly and separate from flocculent sludge. S4. Discharge the supernatant from the reaction tank and retain the granular sludge; S5. Discharge aged sludge and replenish newly generated activated sludge according to the system operating load and adjust the influent volume. S6. Intelligent cycle adjustment based on granular sludge life cycle model, the specific steps are as follows: S6.
1. Collect relevant operating parameters; S6.2 Calculate the life cycle index (LCI) of granular sludge; S6.
3. Dynamically adjust the aeration time, sedimentation time, and sludge discharge ratio of the SBR according to the life cycle stage.
2. The wastewater treatment process based on aerobic granular sludge according to claim 1, characterized in that: The Life Cycle Index (LCI) is calculated as follows: ； in: , , These are the weighting coefficients; , , These are the real-time particle size, settling ratio, and density of granular sludge; , , These are the reference values for particle size, sedimentation ratio, and density at the particle maturity stage, respectively.
3. The wastewater treatment process based on aerobic granular sludge according to claim 2, characterized in that: The lifecycle model is based on LCI and sets different lifecycle stages, including: Growth stage: LCI < first threshold T1; Maturity stage: T1≤LCI≤Second thresholdT2; During the aging stage, LCI ≥ T2.
4. The wastewater treatment process based on aerobic granular sludge according to claim 3, characterized in that: The determination of the lifecycle stage is also based on a combination of one or more of the following: When particle size Larger than the set maximum particle size Furthermore, when the particle density decreases by more than a preset percentage, it is strongly determined to be in the aging stage; When the sedimentation ratio Below the settling ratio performance threshold Shi Qiang is judged to be in the mature stage; When the particle volume ratio The growth rate exceeded the set value At that time, it is determined to be in the growth stage.
5. The wastewater treatment process based on aerobic granular sludge according to claim 1, characterized in that: When the life cycle stage is in the growth stage, the following cycle adjustment strategy is executed: Increase aeration time by 10%-25% to enhance shear force; Settling time is shortened by 10%-20% to enhance selective pressure; Increase the drainage volume appropriately to improve particle enrichment efficiency.
6. The wastewater treatment process based on aerobic granular sludge according to claim 5, characterized in that: When the lifecycle stage is in the mature stage, the following cycle adjustment strategy is implemented: Maintain the aeration time at the set optimal value. ; Settling is performed according to the set set set time to maintain the particle structure; Maintain normal carbon source input levels without adding additional selection pressure.
7. The wastewater treatment process based on aerobic granular sludge according to claim 6, characterized in that: When the lifecycle stage is in the aging stage, the following cycle adjustment strategy is executed: Reduce aeration time by 10%–20% to prevent further particle breakage; Increasing the settling time by 5%–15% enhances the identification of sedimentation of aged particles; Increase the sludge discharge ratio to remove aged particulate sludge; Appropriately increase the carbon source concentration in the influent to promote the formation of new particles.
8. The wastewater treatment process based on aerobic granular sludge according to claim 7, characterized in that: Based on the difference between the current life cycle index and the life cycle index of the previous period The strategy is adjusted as follows: when Less than the preset threshold Maintain the current strategy; when Less than Enhance growth stage adjustment strategies; when Greater than Strengthen aging stage adjustment strategies.
9. A wastewater treatment process based on aerobic granular sludge according to claim 8, characterized in that: The process also includes enabling an anomaly recovery cycle, the specific triggering conditions for which the anomaly recovery cycle is enabled are as follows: Particle size Exceeding the maximum allowable particle size ; Settlement ratio A significant increase leads to a worse settlement ratio; The abnormal fluctuations in the redox potential (ORP) were detected, indicating cavitation inside the particles. During the abnormal recovery cycle, the system reduces aeration time, increases sludge discharge ratio, extends sedimentation time, and reduces influent load.
10. An intelligent wastewater treatment control system, based on the wastewater treatment process based on aerobic granular sludge as described in claims 1-9, characterized in that: include: Granular sludge parameter acquisition module, used to acquire... , Particle parameters such as ρ, VR, and ORP; The life cycle model calculation module is used to calculate LCI and determine the stage of the particle life cycle; The cycle adjustment module is used to automatically adjust the aeration time, sedimentation time, sludge discharge ratio and carbon source addition according to the life cycle stage. An abnormal state handling module is used to execute recovery strategies when the particle state is abnormal; The control and execution unit is used to send execution commands to the aeration system, sludge discharge system, and dosing system.