Integrated gas-lift reactor and method based on high-activity granular sludge separation targets
By monitoring and controlling the liquid flow rate and sludge distribution within the airlift reactor, particle size and activity stratification of highly active granular sludge were achieved, solving the problem of microbial loss in traditional reactors and improving biological treatment efficiency.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- UNIV OF ELECTRONICS SCI & TECH OF CHINA ZHONGSHAN INST
- Filing Date
- 2026-03-19
- Publication Date
- 2026-05-29
Smart Images
Figure CN122102373A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of sludge separation technology, and more specifically, to an integrated airlift reactor and method based on the objective of separating highly active particulate sludge. Background Technology
[0002] Sludge separation is a crucial step in wastewater treatment processes. It involves separating solid particles suspended in the liquid phase from the mixed liquor using physical or physicochemical methods to achieve sludge-water separation. These methods include gravity settling, flotation, and membrane filtration. By utilizing the density difference, particle size difference, or surface characteristics between particles and liquid, sludge is enriched and returned to the reaction zone to maintain system biomass and ensure treatment efficiency.
[0003] Traditional airlift reactors suffer from uneven gas-liquid mixing during operation, making precise control based on particle size differences and activity levels of granular sludge impossible. This results in highly active, large-diameter granular sludge and less active, small-diameter flocculent sludge being simultaneously suspended under upward flow, hindering effective stratification. This leads to the significant loss of dominant microorganisms with vital biological functions in the effluent, reducing biomass within the reactor, shortening sludge age, and significantly decreasing biological treatment efficiency. Furthermore, current technologies lack real-time quantitative monitoring methods for the sludge bed expansion-sedimentation dynamic process, making it impossible to establish a correlation control mechanism between aeration intensity and sludge retention effectiveness. This hinders the targeted enrichment of highly active granular sludge, restricting the long-term stable and efficient operation of the reactor. Therefore, achieving balanced separation and retention of highly active granular sludge to improve the biological treatment efficiency of airlift reactors has become a challenging problem for the industry. Summary of the Invention
[0004] This application provides an integrated airlift reactor and method based on the separation target of highly active granular sludge, which can achieve balanced separation and retention of highly active granular sludge, thereby improving the biological treatment efficiency of the airlift reactor.
[0005] In a first aspect, this application provides an integrated airlift reaction method based on the separation target of highly active granular sludge, comprising: Monitor the liquid upflow velocity and the distribution density of activated granular sludge at different heights within the airlift reactor; Based on the fluctuation characteristics of all liquid upflow velocities, the reaction cycle of the airlift reactor is divided into a sludge expansion and suspension stage and a sludge settling and recirculation stage. By measuring the settling rate of granular sludge and the apparent gas velocity in the liquid phase within each sludge expansion and suspension stage and the sludge settling and recirculation stage, the difference in the expansion rate of the sludge bed in the reactor between adjacent stages is determined. Based on all the differences in expansion rate and the distribution density in different height areas, the particle size classification and activity stratification characteristics of granular sludge in the reactor are determined. Then, based on the particle size classification and activity stratification characteristics, the sludge loss at the effluent outlet is predicted to obtain the evaluation value of the interception and enrichment effect of granular sludge. When the retention and enrichment effect evaluation value is lower than the preset evaluation threshold, the gas lift aeration rate at the bottom of the reactor and the liquid phase circulation rate in the guide tube are balanced in stages.
[0006] In some embodiments, the reaction cycle of the airlift reactor is divided into a sludge expansion and suspension stage and a sludge settling and recirculation stage based on the fluctuation characteristics of all liquid upflow velocities. Specifically, this includes: By plotting the flow velocity fluctuation curves using all the upward flow velocities of the liquid, the peak and trough regions in the flow velocity fluctuation curves are identified as fluctuation characteristics. The period during which the flow velocity in the peak region of the wave characteristic continuously rises to the peak value is marked as the sludge bulking and suspension stage. The period during which the flow velocity in the trough region of the fluctuation characteristic continuously decreases to the trough value is marked as the sludge settling and recirculation stage.
[0007] In some embodiments, determining the difference in expansion rate of the sludge bed in the reactor between adjacent stages by using the settling rate of granular sludge and the apparent gas velocity in the liquid phase during each sludge expansion and suspension stage and sludge settling and recirculation stage specifically includes: Obtain the limiting suspension rate of granular sludge in the upflow during the current expansion and suspension stage and the limiting settling rate of granular sludge in the quiescent flow during the current settling and recirculation stage. Calculate the first ratio of the limiting suspension rate to the current liquid phase apparent gas velocity, and simultaneously calculate the second ratio of the limiting settling rate to the adjacent liquid phase apparent gas velocity. The difference in expansion rate between adjacent stages when the sludge bed transitions from expansion to settling is determined by the first ratio and the second ratio.
[0008] In some embodiments, determining the particle size classification and activity stratification characteristics of the granular sludge within the reactor based on all expansion rate differences and distribution densities at different heights specifically includes: Obtain the sludge distribution density in three height regions: bottom, middle, and top of the reactor. Mark the regions where the distribution density decreases with height as sedimentation enrichment zones. Extract the expansion rate difference value corresponding to the sedimentation enrichment zone, and divide the granular sludge into large-diameter particle groups and small-diameter particle groups according to the size of the expansion rate difference value to obtain the particle size classification of the granular sludge in the reactor. The specific oxygen consumption rate of microorganisms in the area where large-diameter particle groups are located was measured, and the area with a rate value higher than the preset activity threshold was marked as a high-activity stratification, thus obtaining the activity stratification characteristics of granular sludge in the reactor.
[0009] In some embodiments, the effect of predicting the sludge loss at the effluent outlet based on the particle size classification and the activity stratification characteristics, and obtaining the evaluation value of the interception and enrichment effect of granular sludge, specifically includes: The migration trajectory of small-diameter particle groups in the particle size classification at the top of the reactor is tracked to simulate the escape path of small-diameter particles as they are lost with the effluent. The spatial proportion of large-diameter particle groups in the highly active stratification of the active stratification characteristics is statistically analyzed, and the spatial proportion is correlated with the total sludge concentration of the reactor to obtain the retention coefficient of the reactor's sludge retention capacity. The length of the escape path is weighted and fused with the retention coefficient to obtain the evaluation value of the retention and enrichment effect of granular sludge.
[0010] In some embodiments, when the retention and enrichment effect evaluation value is lower than a preset evaluation threshold, the phased balancing of the air rise aeration rate at the bottom of the reactor and the liquid phase circulation rate in the guide tube specifically includes: When the retention enrichment effect evaluation value is lower than the preset threshold, a phase balancing instruction is triggered; During the sludge bulking and suspension stage, the air volume at the bottom is reduced according to the preset first adjustment step to suppress excessive floating of small-diameter sludge particles. During the sludge settling and recirculation stage, the liquid phase circulation rate in the guide tube is increased according to the preset second adjustment step to force the highly active, large-particle sludge to recirculate to the bottom of the reactor.
[0011] In some embodiments, the airlift reactor is a bioreactor based on an internal and external dual circulation structure.
[0012] Secondly, this application provides an integrated airlift reactor based on the objective of separating highly active granular sludge, comprising: The monitoring module is used to monitor the liquid rise velocity and the distribution density of activated granular sludge at different heights within the airlift reactor. The processing module is used to divide the reaction cycle of the airlift reactor into a sludge expansion and suspension stage and a sludge settling and recirculation stage based on the fluctuation characteristics of all liquid upflow velocities. By measuring the settling rate of granular sludge and the apparent gas velocity in the liquid phase within each sludge expansion and suspension stage and the sludge settling and recirculation stage, the difference in the expansion rate of the sludge bed in the reactor between adjacent stages is determined. The processing module is also used to determine the particle size classification and activity stratification characteristics of the granular sludge in the reactor based on all the expansion rate differences and the distribution density of different height areas, and then to predict the sludge loss at the effluent outlet based on the particle size classification and the activity stratification characteristics, so as to obtain the interception and enrichment effect evaluation value of the granular sludge. The execution module is used to perform phased balancing of the air rise aeration rate at the bottom of the reactor and the liquid phase circulation rate in the guide tube when the retention and enrichment effect evaluation value is lower than the preset evaluation threshold.
[0013] Thirdly, this application provides a computer device, the computer device including a memory and a processor, the memory for storing a computer program, and the processor for calling and running the computer program from the memory, so that the computer device executes the above-described integrated airlift reaction method based on the target of highly active granular sludge separation.
[0014] Fourthly, this application provides a computer-readable storage medium storing instructions or code that, when executed on a computer, cause the computer to implement the aforementioned integrated airlift reaction method based on the goal of separating highly active granular sludge.
[0015] The technical solutions provided by the embodiments disclosed in this application have the following beneficial effects: This application provides an integrated airlift reactor and method based on the separation target of highly active granular sludge. The method involves monitoring the liquid upflow velocity and the distribution density of activated granular sludge at different heights within the airlift reactor. Based on the fluctuation characteristics of all liquid upflow velocities, the reaction cycle of the airlift reactor is divided into a sludge expansion and suspension stage and a sludge settling and recirculation stage. The difference in expansion rate of the sludge bed within the reactor between adjacent stages is determined by the settling rate of the granular sludge and the apparent gas velocity in the liquid phase within each sludge expansion and suspension stage and the sludge settling and recirculation stage. Based on all the expansion rate differences and the distribution density at different heights, the particle size distribution and activity stratification characteristics of the granular sludge within the reactor are determined. Then, based on the particle size distribution and activity stratification characteristics, the sludge loss at the effluent outlet is predicted to obtain an evaluation value for the retention and enrichment effect of the granular sludge. When the evaluation value for the retention and enrichment effect is lower than a preset evaluation threshold, the airlift aeration rate at the bottom of the reactor and the liquid phase circulation rate in the guide tube are balanced in stages.
[0016] Therefore, in this application, when the retention and enrichment effect evaluation value is lower than the preset evaluation threshold, the air rise aeration rate at the bottom of the reactor and the liquid phase circulation rate in the guide tube are balanced in stages. First, by determining the expansion rate difference value, the dynamic response quantitative index of the sludge bed during the expansion and settling process can be obtained. This difference value directly reflects the real-time influence of the aeration intensity change at different stages on the sludge settling performance, enabling the control system to accurately identify the balance point between the expansion limit of granular sludge under the action of upflow and the settling potential under the action of gravity. This transforms the originally ambiguous sludge-water separation process into a quantifiable control benchmark, laying the parameter basis for the subsequent selective retention of highly active granular sludge and avoiding sludge loss due to excessive expansion or insufficient mass transfer due to excessively fast settling. Then, by determining the retention and enrichment effect evaluation value, the comprehensive evaluation index of the reactor's ability to retain highly active granular sludge can be obtained. This evaluation value, by integrating the escape risk of small-diameter particles and the enrichment degree of highly active large-diameter particles, constructs a characteristic expression reflecting the dynamic balance between sludge loss and retention. When this value is lower than a preset threshold, the adjustment mechanism is triggered, enabling the reactor to adaptively adjust hydraulic conditions at different operating stages, prioritizing the retention of highly biologically active particulate components. This achieves a shift from passively responding to sludge loss to actively regulating the directional enrichment of particulate sludge, significantly improving the reactor's retention efficiency for functional microorganisms. In summary, based on the above scheme, the balanced separation and retention of highly active particulate sludge can be achieved, thereby improving the biological treatment efficiency of the airlift reactor. Attached Figure Description
[0017] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0018] Figure 1 This is an exemplary flowchart of an integrated airlift reaction method based on a highly active granular sludge separation target, according to some embodiments of this application. Figure 2 This is a flowchart illustrating the process of determining the retention enrichment effect evaluation value according to some embodiments of this application; Figure 3 This is a schematic diagram of the structure of an integrated airlift reactor based on a highly active granular sludge separation target, as shown in some embodiments of this application. Figure 4 This is a schematic diagram of the structure of a computer device for implementing an integrated airlift reaction method based on the objective of separating highly active particulate sludge, according to some embodiments of this application. Detailed Implementation
[0019] To better understand the technical solution of this application, the technical solution of this application will be described in detail below with reference to the accompanying drawings and specific embodiments.
[0020] refer to Figure 1 The figure is an exemplary flow chart of an integrated airlift reaction method based on the separation target of highly active granular sludge, according to some embodiments of this application. The integrated airlift reaction method based on the separation target of highly active granular sludge mainly includes the following steps: In step 101, the liquid upflow velocity and the distribution density of activated granular sludge in different height zones within the airlift reactor are monitored.
[0021] It should be noted that, in this application, the airlift reactor is a bioreactor based on an internal and external dual circulation structure; the liquid upward flow velocity is a hydraulic parameter characterizing the intensity of liquid phase flow within the reactor; and the distribution density of activated granular sludge is a concentration index characterizing the degree of sludge enrichment in different height regions.
[0022] In practice, multiple online flow velocity sensors and sludge concentration meters are installed inside the guide tube and on the side wall of the settling zone of the airlift reactor, at three positions according to the low, medium, and high effective height of the reactor. The flow velocity sensors collect the upward flow velocity of the liquid in the reactor in real time, and the sludge concentration meters collect the distribution density of activated granular sludge in different height areas in real time. Thus, the upward flow velocity of the liquid and the distribution density of activated granular sludge in different height areas of the airlift reactor can be obtained.
[0023] In step 102, the reaction cycle of the airlift reactor is divided into a sludge expansion and suspension stage and a sludge settling and recirculation stage based on the fluctuation characteristics of all liquid upflow velocities. The difference in expansion rate of the sludge bed in the reactor between adjacent stages is determined by the settling rate of granular sludge and the apparent gas velocity in the liquid phase within each sludge expansion and suspension stage and sludge settling and recirculation stage.
[0024] In some embodiments, dividing the reaction cycle of an airlift reactor into a sludge expansion and suspension stage and a sludge settling and recirculation stage based on the fluctuation characteristics of all liquid upflow velocities can be achieved using the following steps: By plotting the flow velocity fluctuation curves using all the upward flow velocities of the liquid, the peak and trough regions in the flow velocity fluctuation curves are identified as fluctuation characteristics. The period during which the flow velocity in the peak region of the wave characteristic continuously rises to the peak value is marked as the sludge bulking and suspension stage. The period during which the flow velocity in the trough region of the fluctuation characteristic continuously decreases to the trough value is marked as the sludge settling and recirculation stage.
[0025] It should be noted that, in this application, the velocity fluctuation curve is a graphical record reflecting the continuous change trend of the liquid upward velocity over time; the peak region is a key segment indicating the location where the liquid upward velocity reaches a local maximum value in the time series; the trough region is a key segment indicating the location where the liquid upward velocity reaches a local minimum value in the time series; the fluctuation characteristics are used as the basis for classifying different hydraulic states within the reaction cycle; the sludge expansion and suspension stage is used to characterize the process stage in which the sludge bed in the reactor is pushed by the upward flow and exhibits an expansion and suspension state; the sludge settling and reflux stage is used to characterize the process stage in which the sludge particles in the reactor are subjected to gravity and exhibit a settling and reflux flow state.
[0026] In specific implementation, firstly, a flow velocity fluctuation curve is plotted using all the upward flow velocities of the liquid. Then, the peak and trough regions in the flow velocity fluctuation curve are identified as fluctuation features. This can be achieved by: using time as the abscissa and the value of the upward flow velocity as the ordinate, fitting and connecting continuous flow velocity data points to plot a complete flow velocity fluctuation curve. The undulation shape of this flow velocity fluctuation curve is observed. The area around the highest point of the curve, where the flow velocity value is significantly higher than that of the adjacent segment, is identified as the peak region. The area around the lowest point of the curve, where the flow velocity value is significantly lower than that of the adjacent segment, is identified as the trough region. The identified peak and trough regions are used together as fluctuation features to divide the reaction stages. Then, the period when the flow velocity in the peak region of the fluctuation feature continuously rises to its peak value is marked as the sludge bulking and suspension stage. This can be achieved by: retrieving all peak region data from the already identified fluctuation features. For each peak region... The process involves tracing the trajectory of the rising liquid velocity within a given region, identifying the complete time interval from which the velocity increases continuously from a lower point adjacent to the left, eventually reaching the highest point within the peak region. This time interval is defined as the period of continuous velocity increase to the peak value, and all periods within the reaction cycle that meet this characteristic are uniformly marked as the sludge bulking and suspension stage. Finally, the period of continuous velocity decrease to the trough value in the trough region of the fluctuation characteristics can be marked as the sludge settling and recirculation stage. This can be achieved by retrieving all trough region data from the identified fluctuation characteristics. For each trough region, the trajectory of the rising liquid velocity within that region is traced, identifying the complete time interval from which the velocity decreases continuously from a higher point adjacent to the left, eventually reaching the lowest point within the trough region. This time interval is defined as the period of continuous velocity decrease to the trough value, and all periods within the reaction cycle that meet this characteristic are uniformly marked as the sludge settling and recirculation stage.
[0027] In some embodiments, the difference in expansion rate of the sludge bed in the reactor between adjacent stages can be determined by the settling rate of granular sludge and the apparent gas velocity in the liquid phase during each sludge expansion and suspension stage and sludge settling and recirculation stage using the following steps: Obtain the limiting suspension rate of granular sludge in the upflow during the current expansion and suspension stage and the limiting settling rate of granular sludge in the quiescent flow during the current settling and recirculation stage. Calculate the first ratio of the limiting suspension rate to the current liquid phase apparent gas velocity, and simultaneously calculate the second ratio of the limiting settling rate to the adjacent liquid phase apparent gas velocity. The difference in expansion rate between adjacent stages when the sludge bed transitions from expansion to settling is determined by the first ratio and the second ratio.
[0028] It should be noted that, in this application, the limiting suspension rate is the critical flow velocity value used to maintain the granular sludge in a suspended state in the upflow without being washed away; the limiting settling rate is the maximum settling velocity that the granular sludge can achieve by its own weight in a static fluid; the first ratio is a dimensionless number reflecting the degree of matching between the granular sludge suspension requirement and the current actual aeration intensity; the second ratio is a dimensionless number reflecting the comparison between the granular sludge settling potential and the aeration intensity of the adjacent stage; and the expansion rate difference value is a process parameter used to quantify the volume change of the sludge bed when it transitions from an expanded state to a settling state.
[0029] In practice, the following method can be used to obtain the limiting suspension rate of granular sludge in the upflow during the current expansion and suspension stage and the limiting settling rate of granular sludge in the quiescent flow during the current settling and recirculation stage: During reactor operation, when the process enters the marked sludge expansion and suspension stage, the motion trajectory of a single representative granular sludge is tracked by an image recognition system installed in the reactor. The instantaneous water flow velocity when the particle is lifted by the water flow in the upflow and no longer continues to rise, but only maintains a rolling or shaking state in place, is observed and recorded as the limiting suspension rate of granular sludge in the upflow. When the process enters the marked sludge settling and recirculation stage, the aeration device of the reactor is temporarily shut down to create a near-static liquid environment. The terminal velocity of the granular sludge as it settles uniformly in the static liquid is observed through settling column tests or online imaging technology, and this velocity is recorded as the ultimate settling rate of the granular sludge in the static flow. Then, the first ratio of the ultimate suspension rate to the apparent gas velocity of the liquid phase in the current stage is calculated. At the same time, the second ratio of the ultimate settling rate to the apparent gas velocity of the liquid phase in the adjacent stage can be calculated as follows: the total gas flow rate of the aeration device in the current expansion suspension stage is read from the reactor's online flow meter, and the total gas flow rate is divided by the cross-sectional area of the empty tower of the reactor to calculate the apparent gas velocity of the liquid phase in the current stage. Divide the limiting suspension velocity by the apparent gas velocity of the liquid phase in the current stage calculated above, and record the result of the division as the first ratio. Simultaneously, read the total gas flow rate of the aeration device in the next stage immediately adjacent to the current stage from the reactor's online flow meter, and divide this total gas flow rate by the empty tower cross-sectional area of the reactor to calculate the apparent gas velocity of the liquid phase in the adjacent stage. Divide the limiting settling velocity by the apparent gas velocity of the liquid phase in the adjacent stage, and record the result of the division as the second ratio. Finally, determine the sludge bed between adjacent stages using the first ratio and the second ratio. The difference in expansion rate when the sludge bed transitions from expansion to settling can be achieved by subtracting the first ratio from the second ratio. Specifically, the second ratio is subtracted from the first ratio, and the resulting difference is the difference in expansion rate between adjacent stages when the sludge bed transitions from expansion to settling. For example, when the first ratio is larger and the second ratio is smaller, it means that the aeration is relatively weaker in the expansion stage and relatively stronger in the settling stage. In this case, the difference in expansion rate will reflect the extent of volume shrinkage of the sludge bed during the transition period.
[0030] In step 103, the particle size classification and activity stratification characteristics of the granular sludge in the reactor are determined based on all the expansion rate differences and the distribution density of different height regions. Then, the sludge loss at the effluent outlet is predicted based on the particle size classification and the activity stratification characteristics to obtain the evaluation value of the interception and enrichment effect of the granular sludge.
[0031] In some embodiments, determining the particle size distribution and activity stratification characteristics of the granular sludge within the reactor based on all expansion rate differences and distribution densities at different heights can be achieved using the following steps: Obtain the sludge distribution density in three height regions: bottom, middle, and top of the reactor. Mark the regions where the distribution density decreases with height as sedimentation enrichment zones. Extract the expansion rate difference value corresponding to the sedimentation enrichment zone, and divide the granular sludge into large-diameter particle groups and small-diameter particle groups according to the size of the expansion rate difference value to obtain the particle size classification of the granular sludge in the reactor. The specific oxygen consumption rate of microorganisms in the area where large-diameter particle groups are located was measured, and the area with a rate value higher than the preset activity threshold was marked as a high-activity stratification, thus obtaining the activity stratification characteristics of granular sludge in the reactor.
[0032] It should be noted that, in this application, the bottom of the reactor is the sludge accumulation area for containing settled granular sludge; the middle of the reactor is the main reaction area for sludge-water mixing and mass transfer; the top of the reactor is the area for sludge-water separation and clarified water overflow; the settling enrichment zone is the dominant area characterized by the large-scale deposition and aggregation of granular sludge under gravity; the large-diameter particle group is the aggregate of granular sludge with a larger diameter and better settling performance; the small-diameter particle group is the aggregate of granular sludge with a smaller diameter and easy to be washed away by water; particle size classification is the classification result used to distinguish the distribution of granular sludge of different sizes in the reactor; high-activity stratification is the dominant area characterized by strong microbial metabolic capacity and high pollutant degradation efficiency; the activity stratification characteristics describe the spatial distribution law of the differences in microbial activity of granular sludge in different height areas.
[0033] In practice, the sludge distribution density is first obtained at three height regions: the bottom, middle, and top of the reactor. Regions where the distribution density decreases with height are designated as settling and enrichment zones. This can be achieved by reading the sludge distribution density values from multiple sludge concentration meters installed at different heights within the reactor, specifically at the bottom, middle, and top sampling points. The sludge distribution densities at these three heights are then compared in order from top to bottom. If the sludge density at the bottom is greater than that in the middle, and the sludge density in the middle is greater than that at the top, showing a pattern of increasing sludge density with decreasing height, then the bottom region and the continuous spatial range extending from the bottom to the middle are marked as a sedimentation enrichment zone. For example, when the density at the top is 2 grams per liter, the density in the middle is 8 grams per liter, and the density at the bottom is 15 grams per liter, the area from the bottom to the middle is identified as a sedimentation enrichment zone. Then, the expansion rate difference value corresponding to the sedimentation enrichment zone is extracted. Based on the magnitude of the expansion rate difference value, the granular sludge is divided into large-diameter particle groups and small-diameter particle groups. The particle size classification of the granular sludge in the reactor can be achieved in the following way: retrieve the data value corresponding to the current sedimentation enrichment zone formation process in time from all expansion rate difference values. For the sludge sample in the sedimentation enrichment zone, measure the equivalent diameter of each granular sludge particle and associate it with the expansion rate difference value at the location of the particle; set a particle size classification... A threshold is established, classifying all granular sludge particles with a diameter greater than the threshold into the large-size particle group and all granular sludge particles with a diameter less than or equal to the threshold into the small-size particle group. The distribution range of the large-size particle group and the small-size particle group within the reactor is distinguished and recorded, forming the particle size classification of the granular sludge within the reactor. For example, particles with a diameter greater than 0.5 mm are classified as large-size particles, and particles with a diameter less than or equal to 0.5 mm are classified as small-size particles. Finally, the specific oxygen consumption rate of microorganisms in the area where the large-size particle group is located is measured, and areas with rate values higher than a preset activity threshold are marked as high-activity stratification. The activity stratification characteristics of the granular sludge within the reactor can be obtained by the following method: within the identified distribution area of the large-size particle group, granular sludge samples are collected in the area using an online respirator or portable detection device. The collected sludge samples are placed in a sealed respirator bottle, and the oxygen consumption per unit mass of sludge per unit time is measured. This measured value is recorded as the specific oxygen consumption rate of microorganisms. The measured specific oxygen consumption rate of microorganisms is compared with the activity threshold pre-stored in the control system. If the specific oxygen consumption rate of microorganisms in a certain area is higher than the preset activity threshold, the area is marked as a high-activity stratification. The locations and ranges of all areas marked as high-activity stratification are summarized to form the activity stratification characteristics of granular sludge in the reactor.For example, when the preset activity threshold is 20 mg of oxygen consumed per gram per hour, areas with measured values higher than 20 are marked as high-activity stratification.
[0034] In some embodiments, the sludge loss at the effluent outlet is predicted based on the particle size classification and the activity stratification characteristics to obtain an evaluation value for the retention and enrichment effect of granular sludge, for reference. Figure 2 The figure is a flowchart illustrating the process of determining the retention and enrichment effect evaluation value in some embodiments of this application. In this embodiment, the determination of the retention and enrichment effect evaluation value can be achieved by the following steps: In step 1031, the migration trajectory of the small-diameter particle group in the particle size classification at the top of the reactor is tracked, thereby simulating the escape path of the small-diameter particles as they are lost with the effluent. In step 1032, the spatial proportion of large-diameter particle groups in the highly active stratification of the active stratification characteristics is statistically analyzed, and the spatial proportion is correlated with the total sludge concentration of the reactor to obtain the sludge retention capacity retention coefficient of the reactor. In step 1033, the length of the escape path and the interception coefficient are weighted and fused to obtain the interception and enrichment effect evaluation value of the granular sludge.
[0035] It should be noted that, in this application, the escape path is a virtual route used to simulate the movement of small-diameter granular sludge from the main area of the reactor to the outlet and its eventual loss; the retention coefficient is a quantitative parameter used to comprehensively evaluate the reactor's ability to retain highly active large-diameter particles within the system; and the retention and enrichment effect evaluation value is the final indicator used to comprehensively evaluate the reactor's ability to retain and enrich highly active granular sludge.
[0036] In specific implementation, firstly, the migration trajectory of small-diameter particle groups in the particle size classification at the top of the reactor is tracked. Then, the escape path of these small-diameter particles carried away by the effluent can be simulated as follows: All granular sludge belonging to the small-diameter particle group are identified from the particle size classification results. Using an online camera system installed at the top of the reactor, the movement of these identified small-diameter particle groups near the effluent outlet is continuously captured. Image tracking algorithms are used to analyze the positional changes of the same particle in consecutive frames, and the migration trajectory of the particle moving from the central area at the top of the reactor towards the effluent outlet is plotted. The trajectory is then analyzed using a flow meter installed at the effluent outlet. The meter reads the instantaneous velocity of the water flowing out of the reactor and uses this instantaneous velocity as the driving force parameter for particle movement. Combined with the previously plotted migration trajectory, a fluid dynamics simulation method is used to deduce the complete motion path of small-diameter particle groups being carried out of the reactor under the suction of the outlet. This simulated motion path is recorded as the escape path of small-diameter particles lost with the effluent. Then, the spatial proportion of large-diameter particle groups in the highly active stratification characteristic is statistically analyzed. This spatial proportion is correlated with the total sludge concentration of the reactor to obtain the sludge retention capacity retention coefficient of the reactor. This can be achieved in the following way: from the active stratification... The system retrieves all regions marked as highly active strata from the stratification features. Within each highly active stratum, it identifies the volume of granular sludge belonging to the large-diameter particle group. This volume is divided by the reactor's effective total volume to calculate the spatial proportion of large-diameter particles within the highly active stratum in the entire reactor. The system reads the current total sludge concentration from the reactor's online sludge concentration meter. The calculated spatial proportion is multiplied by the read total sludge concentration; the spatial proportion is used as the multiplier, and the total sludge concentration as the multiplicand. The resulting value is the sludge retention coefficient of the reactor. A larger coefficient value indicates a stronger ability of the reactor to retain highly active, large-diameter particles. Finally, the weighted fusion of the escape path length and the retention coefficient yields the evaluation value for the retention and enrichment effect of granular sludge. This can be achieved as follows: Extract the total length of the escape path from the simulation results; this length reflects the ease with which small-diameter particles are lost, with a longer path indicating less particle loss. Extract the retention coefficient from the calculation results; this coefficient reflects the reactor's ability to retain highly active, large-diameter particles. Assign a first weighting coefficient to the escape path length and a second weighting coefficient to the retention coefficient. Multiply the escape path length by the first weighting coefficient and multiply the retention coefficient by the second weighting coefficient. Add the results of the two multiplications; the sum is the evaluation value for the retention and enrichment effect of granular sludge. A higher evaluation value indicates a better retention and enrichment effect of the reactor for highly active granular sludge.
[0037] In step 104, when the retention and enrichment effect evaluation value is lower than the preset evaluation threshold, the gas lift aeration rate at the bottom of the reactor and the liquid phase circulation rate in the guide tube are balanced in stages.
[0038] In some embodiments, when the retention and enrichment effect evaluation value is lower than a preset evaluation threshold, the following steps can be used to achieve a phased balance between the air rise aeration rate at the bottom of the reactor and the liquid phase circulation rate in the guide tube: When the retention enrichment effect evaluation value is lower than the preset threshold, a phase balancing instruction is triggered; During the sludge bulking and suspension stage, the air volume at the bottom is reduced according to the preset first adjustment step to suppress excessive floating of small-diameter sludge particles. During the sludge settling and recirculation stage, the liquid phase circulation rate in the guide tube is increased according to the preset second adjustment step to force the highly active, large-particle sludge to recirculate to the bottom of the reactor.
[0039] In specific implementation, firstly, when the retention and enrichment effect evaluation value is lower than a preset threshold, triggering a stage balance command can be achieved in the following way: if the value of the retention and enrichment effect evaluation value is less than the preset threshold value, it indicates that the current reactor's retention capacity for highly active granular sludge is insufficient, and intervention adjustment needs to be initiated. After recognizing this comparison result, the control system automatically generates a stage balance command to initiate subsequent adjustment actions and sends the command to the actuator. Then, during the sludge expansion and suspension stage, reducing the bottom air rise aeration rate according to the preset first adjustment step size to suppress excessive floating of small-diameter sludge can be achieved in the following way: the control system identifies whether the current reactor operation period belongs to the sludge expansion and suspension stage marked in the previous step. When it is confirmed that it is in the sludge expansion and suspension stage and a stage balance command has been received, the control system reads the pre-stored first adjustment step size value and sends an adjustment signal to the aeration valve or blower at the bottom of the reactor. The current airflow rate is reduced by the magnitude of the first adjustment step. With the reduced aeration rate, the upward flow velocity within the reactor decreases accordingly, weakening the lifting force of the upward flow on the granular sludge. This prevents small-diameter sludge particles, which would normally be easily carried to the top by the water flow, from continuing to rise at a lower velocity, thus inhibiting the tendency of small-diameter sludge particles to float excessively to the top of the reactor. Finally, in the sludge settling and recirculation stage, the liquid phase circulation rate within the guide tube is increased by the preset second adjustment step to force the highly active, large-diameter sludge back to the bottom of the reactor. This can be achieved as follows: The control system identifies whether the current reactor operation belongs to the sludge settling and recirculation stage previously marked. When it is confirmed to be in the sludge settling and recirculation stage and a stage balance command has been received, the control system reads the pre-stored second adjustment step value and sends an adjustment signal to the propeller or circulation pump installed inside the guide tube, increasing the current liquid phase circulation rate by the magnitude of the second adjustment step. After the liquid phase circulation rate is increased, the downward flow of liquid in the guide tube accelerates, which enhances the driving force for transporting highly active large-particle sludge to the bottom of the reactor. This forces the large-particle sludge that is settling to be pushed to the bottom area of the reactor, preventing it from staying in the middle of the reactor or floating back up due to water flow disturbance during the settling process.
[0040] Furthermore, in another aspect of this application, in some embodiments, this application provides an integrated airlift reactor based on the objective of separating highly active granular sludge, referencing... Figure 3 The figure is a schematic diagram of an integrated airlift reactor based on the goal of separating highly active granular sludge, according to some embodiments of this application. The integrated airlift reactor includes a monitoring module 201, a processing module 202, and an execution module 203, which are described below: Monitoring module 201, in this application, is mainly used to monitor the liquid rising velocity and the distribution density of activated granular sludge in different height areas within the airlift reactor. Processing module 202, in this application, is used to divide the reaction cycle of the airlift reactor into a sludge expansion and suspension stage and a sludge settling and recirculation stage based on the fluctuation characteristics of all liquid upflow velocities. By the settling rate of granular sludge and the apparent gas velocity of the liquid phase in each sludge expansion and suspension stage and sludge settling and recirculation stage, the difference in expansion rate of the sludge bed in the reactor between adjacent stages is determined. It should be noted that the processing module 202 is also used to determine the particle size classification and activity stratification characteristics of the granular sludge in the reactor based on all the expansion rate difference values and the distribution density of different height areas, and then to predict the sludge loss at the outlet based on the particle size classification and the activity stratification characteristics, so as to obtain the interception and enrichment effect evaluation value of the granular sludge. The execution module 203 in this application is mainly used to perform phased balancing of the air rise aeration rate at the bottom of the reactor and the liquid phase circulation rate in the guide tube when the interception and enrichment effect evaluation value is lower than the preset evaluation threshold.
[0041] The foregoing has detailed examples of an integrated airlift reactor and method based on the target of highly active granular sludge separation provided in this application. It is understood that the corresponding apparatus includes hardware structures and / or software modules for performing each function in order to achieve the aforementioned functions. Those skilled in the art should readily recognize that this application can be implemented in hardware or a combination of hardware and computer software, based on the units and algorithm steps of the examples described in conjunction with the embodiments disclosed herein. Whether a function is executed in hardware or by computer software driving hardware depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.
[0042] In some embodiments, this application also provides a computer device, the computer device including a memory and a processor, the memory for storing a computer program, and the processor for calling and running the computer program from the memory, so that the computer device performs the above-described integrated airlift reaction method based on the target of highly active granular sludge separation.
[0043] In some embodiments, reference Figure 4The dashed lines in the figure indicate that the unit or module is optional. This figure is a schematic diagram of the structure of a computer device for implementing an integrated airlift reaction method based on the separation target of highly active granular sludge, according to an embodiment of this application. The integrated airlift reaction method based on the separation target of highly active granular sludge described in the above embodiments can be achieved through… Figure 4 The computer device shown is used to implement this, and the computer device includes at least one processor 301, a memory 302 and at least one communication unit 305. The computer device may be a terminal device, a server or a chip.
[0044] Processor 301 can be a general-purpose processor or a special-purpose processor. For example, processor 301 can be a central processing unit (CPU), which can be used to control computer devices, execute software programs, and process data from software programs. The computer device may also include a communication unit 305 for inputting (receiving) and outputting (transmitting) signals.
[0045] For example, the computer device may be a chip, and the communication unit 305 may be the input and / or output circuit of the chip, or the communication unit 305 may be the communication interface of the chip, which may be a component of a terminal device, network device or other device.
[0046] For example, the computer device may be a terminal device or a server, and the communication unit 305 may be a transceiver of the terminal device or the server, or the communication unit 305 may be a transceiver circuit of the terminal device or the server.
[0047] The computer device may include one or more memories 302 storing a program 304. The program 304 can be executed by a processor 301 to generate instructions 303, causing the processor 301 to execute the method described in the above method embodiments according to the instructions 303. Optionally, the memory 302 may also store data (such as a target audit model). Optionally, the processor 301 may also read data stored in the memory 302, which may be stored at the same storage address as the program 304, or it may be stored at a different storage address than the program 304.
[0048] The processor 301 and memory 302 can be configured separately or integrated together, for example, integrated on the system on chip (SOC) of the terminal device.
[0049] It should be understood that each step of the above method embodiment can be completed by hardware logic circuits or software instructions in the processor 301. The processor 301 can be a CPU, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, such as discrete gates, transistor logic devices, or discrete hardware components.
[0050] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.
[0051] For example, in some embodiments, this application also provides a computer-readable storage medium storing instructions or code that, when executed on a computer, cause the computer to implement the above-described integrated airlift reaction method based on the goal of separating highly active granular sludge.
[0052] Although preferred embodiments of this application have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this application.
[0053] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.
Claims
1. An integrated airlift reaction method based on the separation target of highly active granular sludge, characterized in that, Includes the following steps: Monitor the liquid upflow velocity and the distribution density of activated granular sludge at different heights within the airlift reactor; Based on the fluctuation characteristics of all liquid upflow velocities, the reaction cycle of the airlift reactor is divided into a sludge expansion and suspension stage and a sludge settling and recirculation stage. By measuring the settling rate of granular sludge and the apparent gas velocity in the liquid phase within each sludge expansion and suspension stage and the sludge settling and recirculation stage, the difference in the expansion rate of the sludge bed in the reactor between adjacent stages is determined. Based on all the differences in expansion rate and the distribution density in different height areas, the particle size classification and activity stratification characteristics of granular sludge in the reactor are determined. Then, based on the particle size classification and activity stratification characteristics, the sludge loss at the effluent outlet is predicted to obtain the evaluation value of the interception and enrichment effect of granular sludge. When the retention and enrichment effect evaluation value is lower than the preset evaluation threshold, the gas lift aeration rate at the bottom of the reactor and the liquid phase circulation rate in the guide tube are balanced in stages.
2. The method as described in claim 1, characterized in that, Based on the fluctuation characteristics of all liquid upflow velocities, the reaction cycle of the airlift reactor is divided into a sludge expansion and suspension stage and a sludge settling and recirculation stage, specifically including: By plotting the flow velocity fluctuation curves using all the upward flow velocities of the liquid, the peak and trough regions in the flow velocity fluctuation curves are identified as fluctuation characteristics. The period during which the flow velocity in the peak region of the wave characteristic continuously rises to the peak value is marked as the sludge bulking and suspension stage. The period during which the flow velocity in the trough region of the fluctuation characteristic continuously decreases to the trough value is marked as the sludge settling and recirculation stage.
3. The method as described in claim 1, characterized in that, The difference in sludge bed expansion rate between adjacent stages was determined by the settling rate of granular sludge and the apparent gas velocity in the liquid phase during each sludge expansion and suspension stage and the sludge settling and recirculation stage. Obtain the limiting suspension rate of granular sludge in the upflow during the current expansion and suspension stage and the limiting settling rate of granular sludge in the quiescent flow during the current settling and recirculation stage. Calculate the first ratio of the limiting suspension rate to the current liquid phase apparent gas velocity, and simultaneously calculate the second ratio of the limiting settling rate to the adjacent liquid phase apparent gas velocity. The difference in expansion rate between adjacent stages when the sludge bed transitions from expansion to settling is determined by the first ratio and the second ratio.
4. The method as described in claim 1, characterized in that, Based on all the differences in expansion rates and the distribution density in different height regions, the particle size classification and activity stratification characteristics of the granular sludge in the reactor were determined, specifically including: Obtain the sludge distribution density in three height regions: bottom, middle, and top of the reactor. Mark the regions where the distribution density decreases with height as sedimentation enrichment zones. Extract the expansion rate difference value corresponding to the sedimentation enrichment zone, and divide the granular sludge into large-diameter particle groups and small-diameter particle groups according to the size of the expansion rate difference value to obtain the particle size classification of the granular sludge in the reactor. The specific oxygen consumption rate of microorganisms in the area where large-diameter particle groups are located was measured, and the area with a rate value higher than the preset activity threshold was marked as a high-activity stratification, thus obtaining the activity stratification characteristics of granular sludge in the reactor.
5. The method as described in claim 1, characterized in that, Based on the particle size classification and the activity stratification characteristics, the sludge loss at the effluent outlet is predicted, and the evaluation value of the granular sludge retention and enrichment effect is obtained, specifically including: The migration trajectory of small-diameter particle groups in the particle size classification at the top of the reactor is tracked to simulate the escape path of small-diameter particles as they are lost with the effluent. The spatial proportion of large-diameter particle groups in the highly active stratification of the active stratification characteristics is statistically analyzed, and the spatial proportion is correlated with the total sludge concentration of the reactor to obtain the retention coefficient of the reactor's sludge retention capacity. The length of the escape path is weighted and fused with the retention coefficient to obtain the evaluation value of the retention and enrichment effect of granular sludge.
6. The method as described in claim 1, characterized in that, When the retention and enrichment effect evaluation value is lower than the preset evaluation threshold, the phased balancing of the air rise aeration rate at the bottom of the reactor and the liquid phase circulation rate in the guide tube specifically includes: When the retention enrichment effect evaluation value is lower than the preset threshold, a phase balancing instruction is triggered; During the sludge bulking and suspension stage, the air volume at the bottom is reduced according to the preset first adjustment step to suppress excessive floating of small-diameter sludge particles. During the sludge settling and recirculation stage, the liquid phase circulation rate in the guide tube is increased according to the preset second adjustment step to force the highly active, large-particle sludge to recirculate to the bottom of the reactor.
7. The method as described in claim 1, characterized in that, The airlift reactor is a bioreactor based on an internal and external dual circulation structure.
8. An integrated airlift reactor based on the objective of separating highly active granular sludge, characterized in that, include: The monitoring module is used to monitor the liquid rise velocity and the distribution density of activated granular sludge at different heights within the airlift reactor. The processing module is used to divide the reaction cycle of the airlift reactor into a sludge expansion and suspension stage and a sludge settling and recirculation stage based on the fluctuation characteristics of all liquid upflow velocities. By measuring the settling rate of granular sludge and the apparent gas velocity in the liquid phase within each sludge expansion and suspension stage and the sludge settling and recirculation stage, the difference in the expansion rate of the sludge bed in the reactor between adjacent stages is determined. The processing module is also used to determine the particle size classification and activity stratification characteristics of the granular sludge in the reactor based on all the expansion rate differences and the distribution density of different height areas, and then to predict the sludge loss at the effluent outlet based on the particle size classification and the activity stratification characteristics, so as to obtain the interception and enrichment effect evaluation value of the granular sludge. The execution module is used to perform phased balancing of the air rise aeration rate at the bottom of the reactor and the liquid phase circulation rate in the guide tube when the retention and enrichment effect evaluation value is lower than the preset evaluation threshold.
9. A computer device, characterized in that, The computer device includes a memory and a processor. The memory is used to store computer programs, and the processor is used to call and run the computer programs from the memory, causing the computer device to perform the integrated airlift reaction method based on the high-activity granular sludge separation target as described in any one of claims 1 to 7.
10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores instructions or code that, when executed on a computer, cause the computer to implement the integrated airlift reaction method based on the target of highly active granular sludge separation as described in any one of claims 1 to 7.