Control method and system based on in-situ expansion without water stop of sewage plant

Abstract

This invention belongs to the technical field of wastewater treatment, and relates to a control method and system for in-situ expansion of wastewater treatment plants without interrupting water supply. The method includes: acquiring measured operating parameters of the original biological system, generating a system baseline route containing trigger thresholds and initial dosing gradients, and establishing a control closed loop; driving the dosing device to inject composite powder carriers at a gradient to generate a dual-sludge micro-ecological framework, and controlling the device to output a continuous bubble flow to obtain an enriched biological system; calculating the decay slope of the dissolved oxygen time series curve, comparing it with the threshold to generate a trigger command, and releasing high-pressure pulsed nanobubble clusters to the framework to perform regeneration operations; adjusting the sludge return ratio according to suspended solids concentration and settling indices, and adjusting the carrier dosage after system stabilization to obtain a steady-state expanded biological system. This invention solves the problem in existing technologies where excessive biofilm growth of biological carriers leads to limited mass transfer and a lack of effective in-situ regeneration mechanisms, making it difficult to maintain the long-term stability of system treatment efficiency.

Description

Technical Field

[0001] This invention belongs to the technical field of wastewater treatment, and relates to a control method and system for in-situ expansion of wastewater treatment plants without interrupting water supply. Background Technology

[0002] With increasingly stringent environmental protection requirements, municipal wastewater treatment plants are facing the dual pressures of increased treatment volume and higher effluent standards. Traditional expansion and renovation solutions, such as constructing new reaction tanks or adding secondary sedimentation tanks, typically involve significant civil engineering work, substantial investment, and lengthy construction periods. Furthermore, the renovation process often necessitates the shutdown of treatment units or the entire plant, impacting wastewater collection and treatment in the region. Therefore, in-situ upgrading and expansion of existing facilities without interrupting service has become a crucial requirement in the water treatment sector.

[0003] To address these needs, existing technologies have proposed in-situ enhancement techniques, primarily including moving bed biofilm reactor technology and powdered activated carbon addition technology. Moving bed biofilm reactor technology adds suspended packing material to the reaction unit, providing a surface for microorganisms to attach and grow, thereby increasing the total biomass within the original tank volume and enhancing pollutant removal efficiency. Powdered activated carbon addition technology utilizes the large specific surface area and adsorption capacity of powdered activated carbon to adsorb recalcitrant organic matter in water. Its particles, acting as flocculation nuclei, also improve the settling performance of activated sludge, thus enhancing effluent quality.

[0004] The aforementioned in-situ enhancement technologies have certain limitations in long-term, high-load operation scenarios. For moving bed biofilm reactor technology, the biofilm on the suspended packing material thickens over time. Once it exceeds a certain range, the mass transfer efficiency between oxygen and substrate into the biofilm decreases, leading to the formation of an anaerobic layer inside the packing material and affecting the bioavailability per unit of packing material. Furthermore, online stripping and regeneration of old biofilm is currently difficult. For powdered activated carbon dosing technology, the adsorption sites easily lose their effectiveness after saturation, typically requiring continuous replenishment of new powdered activated carbon, increasing operating costs. Moreover, the discharge of ineffective activated carbon with excess sludge increases the sludge disposal load. These technologies still require improvement in the online maintenance and recycling of the activity of biological carriers or adsorbents. Summary of the Invention

[0005] In a first aspect, the present invention provides a control method for in-situ expansion of a wastewater treatment plant without interrupting water supply, comprising the following steps: S1. Obtain the measured operating parameters of the native system and generate a system operating baseline route that includes a preset trigger threshold and an initial gradient. S2. Call the system's baseline route and establish a feedback control closed loop consisting of the online monitoring and control system, material feeding equipment, and bubble generating equipment; S3. Drive the material feeding equipment through feedback control closed loop, inject the composite powder carrier into the original system according to the initial feeding gradient, and generate a dual mud micro-ecological skeleton. S4. Control the bubble generating equipment to output a continuous bubble flow to the dual mud micro-ecological framework to obtain an enriched biochemical system; S5. Obtain the real-time dissolved oxygen time series of the enrichment biochemical system, calculate its curve decay slope, compare the curve decay slope with the preset trigger threshold, and generate a forced pulse cavitation trigger command. S6. Responding to the forced pulse cavitation trigger command, control the bubble generating device to release high-pressure pulse nanobubble clusters to the dual mud micro-ecological framework to perform regeneration operation; S7. Obtain online suspended solids concentration data and real-time sludge settling index values ​​during regeneration operation and system response, dynamically adjust the sludge return operation ratio, and adjust the dosage of composite powder carrier after confirming that the regeneration operation has been completed and the system has returned to stability, to obtain a steady-state expanded biochemical system.

[0006] A further aspect of the present invention, step S1, includes the following steps: Acquire measured sludge concentration data, dynamic dissolved oxygen data, influent flow rate data, influent water quality characterization parameters, and effluent water quality characterization parameters of the original treatment system; Based on measured sludge concentration data and effluent quality characterization parameters, a preset trigger threshold including a critical slope parameter is set. The effective influent load is calculated based on influent flow rate data and influent water quality characterization parameters. The initial dosing gradient is set by comparing the effective influent load with dynamic dissolved oxygen data. By integrating the preset trigger threshold with the initial gradient, a baseline route for system operation is generated.

[0007] A further aspect of the present invention, step S2, includes the following steps: Bubble generators are installed at the bottom of the aerobic and anoxic zones of the original system, and material feeding devices are installed at the inlet and outlet. An online monitoring and control system integrating multi-source data sensing probes is deployed within a native system; An online monitoring and control system is established and electrically communicated with both the bubble generating equipment and the material feeding equipment to generate a feedback control closed loop.

[0008] A further aspect of the present invention, step S3, includes the following steps: A composite powder carrier with a spatially rigid porous channel structure was prepared by obtaining diatomaceous earth dry powder and powdered activated carbon and blending them. By controlling the feedback loop to output the initial start command, the material feeding equipment is driven to continuously inject the composite powder carrier into the bottom mixture of the original chemical system according to the initial feeding gradient. The suspended activated sludge in the induced native system aggregates into the confined space of the composite powder carrier, generating a dual-sludge micro-ecological framework.

[0009] A further aspect of the present invention, step S4, includes the following steps: A low-power continuous start-up electrical signal is sent to the bubble generating equipment through an online monitoring and control system; The bubble generator continuously releases a stream of bubbles into the water of the primary treatment system. The continuous flow of air bubbles is guided to penetrate into the internal rigid microchannels of the dual-mud microecological framework, promoting the proliferation of internal functional bacteria and the secretion of adhesive extracellular polymers, thus obtaining an enriched biochemical system.

[0010] A further aspect of the present invention, step S5, includes the following steps: The air supply to the bubble generator is periodically cut off to form a non-aeration measurement window. Real-time dissolved oxygen electrical signals of the aerobic zone water body within the non-aeration measurement window are collected, aligned and converted according to a unified timestamp, and a real-time dissolved oxygen time series is generated. Within the set analysis sliding time window, calculate the decay slope of the real-time dissolved oxygen time series curve; After converting the curve decay slope to a time unit, it is compared with the critical slope parameter in the preset trigger threshold. When the curve decay slope is greater than or equal to the critical slope parameter, it is determined that the surface of the dual mud micro-ecological skeleton is covered with dense aged extracellular polymers, and a forced pulse cavitation trigger command is generated.

[0011] A further aspect of this invention involves calculating the decay slope of a real-time dissolved oxygen time series curve, including the following steps: Obtain the total number of data points within the analysis sliding time window, the timestamp corresponding to each data point, and the measured dissolved oxygen concentration value; Calculate the sum of the products of timestamps and dissolved oxygen concentration values, and multiply by the total number of data points to obtain the first product term; The second product term is obtained by multiplying the sum of the timestamps by the sum of the dissolved oxygen concentration values. Calculate the sum of the squares of the timestamps and multiply it by the total number of data points to obtain the third product term; Calculate the square of the sum of timestamps to obtain the fourth product term; Dividing the difference between the first and second product terms by the difference between the third and fourth product terms yields the slope of the curve's decay.

[0012] A further aspect of the present invention, step S6, includes the following steps: Receives a forced pulse cavitation trigger command, cutting off the continuous gas supply from the bubble generator; The bubble generator instantaneously releases a high-pressure pulse of nanobubble clusters. High-pressure pulsed nanobubble clusters are guided to squeeze into the confined channels of the dual-mud micro-ecological framework, triggering cavitation collapse. By utilizing the fluid microjet generated by cavitation collapse, the dense, aged extracellular polymers on the surface of the dual-sludge micro-ecological framework are separated from the aged and deactivated sludge, thus completing the regeneration operation.

[0013] A further aspect of the present invention, step S7, includes the following steps: Acquire online suspended solids concentration data and real-time sludge settling index values ​​during regeneration operations and system response; Based on online suspended solids concentration data and real-time sludge settling index values, the valve opening of the sludge return pump unit is dynamically adjusted to maintain the sludge return operation ratio within the preset safe and stable range. The dense, aged extracellular polymers that are stripped off are guided into the anoxic aquatic environment along with the returned sludge, where they are transformed into an endogenous supplementary carbon source to support the denitrification reaction.

[0014] Secondly, the present invention provides a control system for in-situ expansion of a wastewater treatment plant without interrupting water supply, comprising the following modules: The baseline route generation module is used to obtain the measured operating parameters of the native system and generate a system operating baseline route that includes a preset trigger threshold and an initial gradient. The closed-loop system construction module is used to call the system's operating baseline route and establish a feedback control closed loop consisting of an online monitoring and control system, material feeding equipment, and bubble generating equipment. The micro-ecological framework construction module is used to drive the material feeding equipment through feedback control closed loop, inject the composite powder carrier into the original system according to the initial feeding gradient, and generate the dual mud micro-ecological framework. The bioaccumulation drive module is used to control the bubble generating device to output a continuous bubble flow to the dual-mud micro-ecological framework to obtain an enriched biochemical system. The mass transfer lag identification module is used to acquire the real-time dissolved oxygen time series of the enrichment biochemical system, calculate its curve decay slope, compare the curve decay slope with the preset trigger threshold, and generate a forced pulse cavitation trigger command. The in-situ physical regeneration module is used to respond to the forced pulse cavitation trigger command, control the bubble generating device to release high-pressure pulse nanobubble clusters to the dual mud micro-ecological framework, and perform regeneration operation; The steady-state compensation control module is used to acquire online suspended solids concentration data and real-time sludge settling index values ​​during regeneration operations and system response, dynamically adjust the sludge return operation ratio, and adjust the dosage of composite powder carrier after confirming that the regeneration operation has been completed and the system has returned to stability, thereby obtaining a steady-state expanded biochemical system.

[0015] In summary, the present invention has the following beneficial technical effects: 1. By adding a composite powder carrier consisting of diatomaceous earth dry powder and powdered activated carbon to the biological treatment system, and coordinating with continuous bubble flow for oxygen supply, a dual-sludge micro-ecological framework is induced. In this structure, the rigid porous structure of diatomaceous earth provides a stable attachment substrate for microorganisms, while the powdered activated carbon utilizes its adsorption properties to enrich the substrate in microscopic regions to guide bacterial attachment. In macroscopic applications, this invention can achieve in-situ expansion under continuous water supply conditions. Specifically, this method can more than double the sludge concentration in the system and increase the treated water volume by 30%-100%, improving the treatment efficiency and economy of the biological treatment system without the need for additional physical structures.

[0016] Meanwhile, the continuous bubble flow, with its longer residence time in water and larger gas-liquid contact area, can permeate oxygen into the internal pores of the micro-ecological framework, improving the mass transfer limitation problem caused by hypoxia inside traditional biofilms. The combination of these characteristics allows suspended activated sludge and attached biofilm to coexist synergistically, which is beneficial for increasing the effective biomass of the system without increasing the existing tank volume, thereby enhancing the overall treatment load and resistance to water quality fluctuations of the system.

[0017] 2. By monitoring the decay slope of the dissolved oxygen time series curve online, the mass transfer retardation state of the carrier biofilm is identified, and a forced pulse cavitation operation is triggered accordingly. This scheme uses the dissolved oxygen decay slope, a macroscopic monitoring data point, as a trigger indicator to characterize the mass transfer efficiency of the microscopic biofilm. It can dynamically reflect the aging and clogging degree of the carrier surface, providing accurate timing for in-situ regeneration. Upon response to the trigger command, a high-pressure pulse nanobubble cluster is instantaneously released, causing cavitation collapse within the confined pores of the carrier. The resulting fluid microjets physically remove the aging biofilm and deactivated sludge. This physical regeneration mechanism reduces secondary pollution and interference with existing biological systems caused by conventional chemical cleaning, helping to maintain the long-term stable operation of the system and the periodic recovery of the biocarrier's activity.

[0018] 3. While performing microscopic in-situ regeneration, the proportion of sludge return operation is dynamically adjusted to guide the stripped dense, aged extracellular polymers to the anoxic zone of the biological system along with the returned sludge. Since the stripped material is mainly composed of organic matter such as polysaccharides and proteins, it can be hydrolyzed and utilized in the anoxic environment, converting it into an endogenous carbon source to support the denitrification process. This operation step achieves the resource recycling of waste biomass within the system. While meeting the carbon source requirements for denitrification, it can reduce the dependence on exogenous carbon sources such as methanol or sodium acetate in conventional processes to a certain extent, which is beneficial for optimizing the denitrification process and controlling the daily operating costs after upgrading and expansion. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. The drawings are used to provide a further understanding of the present invention.

[0020] Figure 1 A flowchart illustrating an embodiment of this application is disclosed.

[0021] Figure 2 A schematic diagram of the mass ratio of the composite powder carrier in the embodiments of this application is disclosed.

[0022] Figure 3 The present application discloses a graph showing the increasing trend of effective sludge concentration during the bioaccumulation process.

[0023] Figure 4 The dissolved oxygen retardation decay curve within the sliding time window in the embodiments of this application is disclosed.

[0024] Figure 5 The in-situ regeneration and the dynamic control response diagram of the reflux operation ratio during the system response period in the embodiments of this application are disclosed.

[0025] Figure 6 A comparison chart of the degradation load standards of underlying pollutants after baseline primordialization and steady-state expansion in the embodiments of this application is disclosed.

[0026] Figure 7 Structural schematic diagrams of embodiments of this application are disclosed. Detailed Implementation

[0027] The following is in conjunction with the appendix Figures 1-7 A preferred description of the present invention is provided below.

[0028] See attached document Figure 1 This invention proposes a control method based on in-situ expansion of a wastewater treatment plant without interrupting water supply, comprising the following steps: S1. Obtain the measured operating parameters of the native system and generate a system operating baseline route that includes a preset trigger threshold and an initial gradient. S2. Call the system's baseline route and establish a feedback control closed loop consisting of the online monitoring and control system, material feeding equipment, and bubble generating equipment; S3. Drive the material feeding equipment through feedback control closed loop, inject the composite powder carrier into the original system according to the initial feeding gradient, and generate a dual mud micro-ecological skeleton. S4. Control the bubble generating equipment to output a continuous bubble flow to the dual mud micro-ecological framework to obtain an enriched biochemical system; S5. Obtain the real-time dissolved oxygen time series of the enrichment biochemical system, calculate its curve decay slope, compare the curve decay slope with the preset trigger threshold, and generate a forced pulse cavitation trigger command. S6. Responding to the forced pulse cavitation trigger command, control the bubble generating device to release high-pressure pulse nanobubble clusters to the dual mud micro-ecological framework to perform regeneration operation; S7. Obtain online suspended solids concentration data and real-time sludge settling index values ​​during regeneration operation and system response, dynamically adjust the sludge return operation ratio, and adjust the dosage of composite powder carrier after confirming that the regeneration operation has been completed and the system has returned to stability, to obtain a steady-state expanded biochemical system.

[0029] In one embodiment of the present invention, step S1 includes the following steps: Acquire measured sludge concentration data, dynamic dissolved oxygen data, influent flow rate data, influent water quality characterization parameters, and effluent water quality characterization parameters of the original treatment system; Based on measured sludge concentration data and effluent quality characterization parameters, a preset trigger threshold including a critical slope parameter is set. The effective influent load is calculated based on influent flow rate data and influent water quality characterization parameters. The initial dosing gradient is set by comparing the effective influent load with dynamic dissolved oxygen data. By integrating the preset trigger threshold with the initial gradient, a baseline route for system operation is generated.

[0030] Specifically, in a primary biochemical system that maintains continuous influent and biological operation, an online monitoring and control system deployed within the biochemical reactor synchronously and at high frequency collects and records multiple key operational data points over a monitoring period sufficient to cover the entire operational fluctuation cycle. The primary biochemical system refers to an existing activated sludge wastewater treatment facility undergoing expansion or renovation, comprising complete units such as a biochemical reactor and a secondary sedimentation tank.

[0031] The online monitoring and control system uses an optical sludge concentration sensor to collect and generate measured sludge concentration data, a fluorescence dissolved oxygen probe to collect and generate dynamic dissolved oxygen data, and online chemical analyzers, such as chemical oxygen demand analyzers and ammonia nitrogen analyzers, to collect and generate influent water quality characterization parameters and effluent water quality characterization parameters, respectively. All data are aligned with a unified timestamp to form a high-dimensional system state time series.

[0032] The measured sludge concentration data, i.e., the mixed liquor suspended solids concentration, is measured using an optical or ultrasonic sludge concentration meter, reflecting the total amount of active microorganisms in the biological reactor. Dynamic dissolved oxygen data refers to the time-varying sequence of dissolved oxygen concentration in the aerobic zone of the biological reactor, measured by an electrochemical or fluorescence dissolved oxygen probe; it is a core indicator characterizing the system's oxygen supply and consumption balance. Effluent water quality characterization parameters are a set of water quality indicators used to evaluate the system's treatment efficiency, typically including chemical oxygen demand (COD), ammonia nitrogen, total nitrogen (TNI), and total phosphorus (TP), all in mg / L. The central processing unit of the online monitoring and control system analyzes the measured sludge concentration data and effluent water quality characterization parameters to determine if the system is currently operating in a stable state. Based on this stable state, a set of preset trigger thresholds for subsequent process control is set. These thresholds are stored in the system memory, and a key parameter is the critical slope parameter for dissolved oxygen inhibition attenuation.

[0033] The preset trigger threshold is a set of preset values. When the real-time monitoring data reaches these values, a specific control action will be triggered; the critical slope parameter for dissolved oxygen inhibition and decay. This is a key parameter in the preset trigger threshold. When the oxygen mass transfer is hindered due to the dense encapsulation of extracellular polymers on the surface of the composite powder carrier and the effective oxygen consumption rate of the internal microorganisms decreases significantly, the dissolved oxygen concentration can reach a gradual critical upper limit of decay rate over time, i.e., approaching zero. This parameter is set based on a large amount of laboratory data and empirical models for similar biofilm carriers. The typical value is in the range of -0.02 (mg / L) / min to -0.06 (mg / L) / min, to ensure that it can be identified in time when the mass transfer efficiency deteriorates significantly.

[0034] Specifically, in one embodiment of the present invention, the expert knowledge base built into the online monitoring and control system stores preset benchmark slope parameters and a multivariate linear compensation mapping model. The processor extracts real-time operating data and dynamically maps and calculates the exact critical slope parameter according to the following formula. : ; In the formula, The preset benchmark critical slope for the expert database is -0.04 (mg / L) / min; and These are the measured sludge concentration data and the set standard sludge concentration, such as 3500 mg / L; and These are the measured COD values ​​of the effluent and the discharge standard limits, such as 50 mg / L; and These are the sludge concentration compensation coefficient and the water quality compensation coefficient, respectively. The value is -0.015. The value is -0.01. This logic allows the computer to automatically calculate a slope threshold with a smaller absolute value when the system is under high sludge load or the effluent quality is close to the red line, thereby triggering forced pulse cavitation in advance.

[0035] Furthermore, the central processing unit calculates the historical average effective influent load of the primary aeration system based on the influent flow data collected by the influent flow meter and the influent water quality characterization parameters, and compares and analyzes it with dynamic dissolved oxygen data to evaluate the oxygen supply capacity and redundancy space of the existing aeration system.

[0036] It should be noted that the effective influent load refers to the mass of the main pollutants entering the biological system per unit time, for example, in kg COD / d.

[0037] Based on the assessment results, an initial dosing gradient for the composite powder carrier used in the start-up phase was established. This gradient defines the initial dosage and subsequent incremental rules, aiming to smoothly guide the system's ecological succession without causing dissolved oxygen collapse. The initial dosing gradient of the composite powder carrier is a time-dependent dosing strategy, with the initial dosage set at 50-100 mg / (L⋅d) based on common experience in the field for starting up high-load systems, to ensure the initiation of microbial attachment and growth without disrupting the system's existing dissolved oxygen balance.

[0038] Ultimately, the central processing unit integrates the preset trigger threshold, which includes the critical slope parameter, with the initial dosing gradient, and encapsulates them into a digital system operation baseline route that includes underlying hardware control instructions and material dosing specifications. This baseline route serves as the basis for all subsequent automated operations. The system operation baseline route is a structured data file that stores all preset control parameters and strategies, acting as an execution blueprint for subsequent steps.

[0039] In one example of the present invention, the daily processing capacity is 20,000 m³. 3 The system was operated on the primary biofilm system of a municipal wastewater treatment plant. First, the online monitoring and control system continuously monitored the system for 72 hours, obtaining the average measured sludge concentration under stable operating conditions as 3800 mg / L, the average dynamic dissolved oxygen in the aerobic zone as 2.5 mg / L, and the effluent chemical oxygen demand (COD) as stable at 45 mg / L. The system's central processing unit (CPU) determined that the system was operating stably. Based on this, the CPU retrieved and set the critical slope parameter for dissolved oxygen inhibition attenuation from its built-in expert knowledge base, specifically for the high-density biofilm system to be constructed. The rate is -0.05 (mg / L) / min. Meanwhile, based on influent water quality monitoring data, the average influent chemical oxygen demand (COD) is 400 mg / L. The effective influent load of the prototyping system is calculated to be... Analysis shows that the current dynamic dissolved oxygen level of 2.5 mg / L can only meet the oxygen demand of a sludge concentration of 3800 mg / L, indicating low oxygen supply redundancy. Therefore, to avoid the risk of hypoxia caused by a rapid increase in sludge concentration due to the addition of the composite powder carrier during the initial startup phase, a conservative initial dosing gradient for the system is set, with an initial dosage of 25 mg / (L⋅d). Finally, the system integrates these parameters into a baseline operating route, which can be represented as a set of parameter pairs, for example: And store it for later use in subsequent steps.

[0040] In one embodiment of the present invention, step S2 includes the following steps: Bubble generators are installed at the bottom of the aerobic and anoxic zones of the original system, and material feeding devices are installed at the inlet and outlet. An online monitoring and control system integrating multi-source data sensing probes is deployed within a native system; An online monitoring and control system is established and electrically communicated with both the bubble generating equipment and the material feeding equipment to generate a feedback control closed loop.

[0041] Specifically, the system's baseline operating route is invoked first, and while maintaining the original hydraulic flow cycle of the system—that is, without interrupting the inflow, outflow, and internal circulation—the external hardware control system and underlying sensing components are assembled. This process begins with engineers operating from the poolside or using a floating platform to lower multiple sets of bubble generators (in the preferred embodiment of this application, a movable nanobubble generator is used as an example) to the bottom of the aerobic and anoxic zones, ensuring uniform bubble coverage according to the pool's geometry. Subsequently, the waterproof power cables and signal control cables from each generator are connected to the newly installed external frequency conversion control system in the onshore control room.

[0042] The portable nanobubble generator is a specialized device capable of generating nanoscale bubbles. It typically employs jet cavitation or electrolysis principles. Its gas-liquid injection end integrates a high-speed electromagnetic pulse valve for extremely rapid response. The selection and deployment density are determined based on the pool area and water depth, generally following the principle of deploying one set for every 50 to 100 square meters of water surface area to ensure uniform aeration. The external frequency conversion control system is an electrical control cabinet that integrates a frequency converter and a programmable logic controller unit. It is used to receive commands from the upper level and adjust the output power and operating frequency of each set of nanobubble generators.

[0043] Meanwhile, another group of technicians installed a variable frequency material feeder at the end of the inlet channel of the original treatment system and at the outlet of the activated sludge return pipeline. They also completed the laying and dredging of the complete material conveying pipeline from the pre-set dry powder silo to the bottom mixing and dissolving tank via a screw conveyor, and then to the variable frequency material feeder via a wear-resistant slurry pump.

[0044] It should be noted that variable frequency material feeders are typically screw-type or vibratory feeders, with their motors driven by frequency converters, enabling milligram-level powder feeding based on control signals. The pre-positioned dry powder silo is a large-capacity container used to store the subsequent required composite powder carrier; its volume must meet at least one week's feeding needs. The function of the bottom-level mixing and dissolving tank is to pre-mix the dry powder with process water to prepare a uniform slurry, thus avoiding dust generation and uneven dissolution problems caused by direct addition of dry powder.

[0045] The multi-source data sensor probes of the online monitoring and control system, which were used to collect data in the previous step, are suspended and deployed at a representative water position in the lower part of the biological treatment tank using a liftable mechanical structure. Crucially, the output port of the central processor of the online monitoring and control system is connected via industrial Ethernet or fieldbus protocols to establish stable electrical communication connections with the external frequency conversion control system and the communication modules of the two frequency conversion material feeders.

[0046] The feedback control closed loop is defined at the information level as follows: real-time data is collected by the online monitoring and control system, and after being judged by the internal algorithm, a control command is generated. This command is connected by electrical communication to drive the external hardware control system and the variable frequency material feeder to perform corresponding actions. After the actions are executed, water quality parameters change, and these changes are captured by the online monitoring and control system, forming a continuous cycle and self-regulating control loop.

[0047] In one example of the present invention, for a daily processing capacity of 20,000 m³ 3 The scene depicts a municipal wastewater treatment plant, where the total surface area of ​​the aerobic and anoxic biological treatment tanks is 1600 m². 2 The system invokes the generated system runtime baseline route and initiates the hardware assembly process. This is based on a 100-meter interval... 2 Following the principle of deploying in groups, engineers used a mechanical crane to sequentially hoist and lower sixteen sets of portable nanobubble generators, each with a rated power of 18kW, to the bottom of the tank without interrupting water flow, distributing them evenly. The waterproof cables of all generators were collected and connected to a newly installed external frequency converter control system with sixteen independent output channels. Simultaneously, a frequency converter material feeder with a feeding range of 2-50 kg / h was installed above the channel where the primary sedimentation tank effluent enters the biological treatment tank, and another frequency converter material feeder of the same specifications was installed on the outlet pipe of the secondary sedimentation tank return sludge pump. Construction workers laid pipelines, extending the 20 m section located in the equipment room...3 Pre-installed dry powder silo and a 2 m 3 The bottom-level mixing and dissolving tank was connected. Finally, the field instrumentation engineer established communication between the main controller of the online monitoring and control system and the controllers of the external frequency converter control system and the two frequency converter material feeders via the Profinet fieldbus. To verify the closed loop, the engineer manually sent a test command from the main control system interface, for example: turn on the No. 5 nanobubble generator, set the power to 50%. When the field confirmed that the No. 5 generator had started as instructed and the external frequency converter control system reported a normal status, it signified that the feedback control closed loop, where physical and signal interactions converged, had been successfully established.

[0048] In one embodiment of the present invention, step S3 includes the following steps: A composite powder carrier with a spatially rigid porous channel structure was prepared by obtaining diatomaceous earth dry powder and powdered activated carbon and blending them. By controlling the feedback loop to output the initial start command, the material feeding equipment is driven to continuously inject the composite powder carrier into the bottom mixture of the original chemical system according to the initial feeding gradient. The suspended activated sludge in the induced native system aggregates into the confined space of the composite powder carrier, generating a dual-sludge micro-ecological framework.

[0049] Specifically, to construct a dual-mud micro-ecological framework with confined pores, a composite powder carrier is first prepared in a pre-placed dry powder silo. This preparation process is performed by a high-shear mixer, which mixes diatomaceous earth dry powder with a predetermined particle size range of 300 to 500 mesh with powdered activated carbon at a mass ratio of 8:1 to 12:1 until a macroscopically uniform powder mixture is formed. This mixture is the composite powder carrier, and its interior naturally forms a spatially rigid porous channel structure due to the stacking of raw material particles.

[0050] The composite powder carrier is a designed microbial immobilization medium. Its particle size of 300 to 500 mesh is chosen to achieve suspension properties similar to activated sludge flocs under hydraulic agitation, preventing rapid settling or loss with water. For example... Figure 2 As shown, a specific mass ratio, namely diatomaceous earth to powdered activated carbon of 8:1 to 12:1, is the key to achieving synergy between structure and function. Taking conventional municipal sewage treatment as an example, the preferred ratio is 10:1. This ratio ensures that the carrier has sufficient mechanical strength and density to facilitate subsequent sedimentation, as well as sufficient biocompatibility and induction ability.

[0051] The feedback control closed loop officially starts the preset program, issuing an initial start command based on the system's operating baseline. This command is transmitted to the control unit of the variable frequency material feeder. The control unit parses the command, converts it into a specific target dosage, and drives the feeder to continuously inject the composite powder carrier into the bottom stirring and dissolving tank at an accurate mass flow rate. After preparing a uniform slurry, it is pumped into the bottom mixing liquid of the original chemical system.

[0052] It should be noted that the initial start command is a digital signal containing specific dosage parameters, and its core is to execute the initial dosing gradient set in the system's operating baseline route; while the target dosing dose is the mass of carrier to be added per unit time calculated based on the system's operating baseline route, and its unit is kg / h.

[0053] After being injected into the water body, the rigid mechanical microskeleton provided by the diatomaceous earth component in the composite powder carrier serves as the structural support for the attachment and growth of microorganisms. At the same time, the microenvironmental directional baiting characteristics of the powdered activated carbon component, namely its strong adsorption capacity, form a local high-concentration organic micro-region around the particles. Through chemotaxis, the activated sludge in the mixed liquor in a suspended state is strongly induced to actively gather, attach, and proliferate into the confined space of the composite powder carrier. Finally, a dense biofilm is generated on the surface of the carrier and in the pores, forming a brand-new dual-sludge micro-ecological framework composed of an inorganic carrier core and an organic biofilm shell with confined pores.

[0054] The dual-sludge micro-ecological framework is an engineered representation of a hybrid ecosystem. The dual sludge refers to the coexistence of two forms of sludge: native suspended activated sludge and newly formed attached biofilm. The confined pores refer to the micron-level channels formed by the accumulation of diatomaceous earth particles, which provide microorganisms with a sanctuary free from hydraulic shear and predation.

[0055] In one example of the present invention, firstly, workers use an industrial weighing system to weigh 4000 kg of diatomaceous earth powder with a particle size of 400 mesh and 400 kg of powdered activated carbon with the same particle size, and then feed them in batches into a 2m³ capacity machine. 3 In a high-shear mixer, the mixture was stirred for 30 minutes to ensure uniform mixing. Then, a total of 4400 kg of the prepared composite powder carrier was transferred to a pre-placed dry powder silo. The central processing unit with feedback control closed loop read the system's operating baseline route and determined that the initial dosing gradient corresponding to the target dosage was 50 mg / (L⋅d). The effective volume of the biochemical tank based on the native system is 14000 m³. 3 The system automatically calculates the total mass of carriers that need to be added daily. This value is converted into an hourly dosage, i.e. Accordingly, the online monitoring and control system simultaneously issued initial start commands to the two variable frequency material feeders installed at the inlet and return ends, setting their respective feed rates to 14.585 kg / h. The feeders injected the powder carrier into the bottom mixing and dissolving tank, preparing a slurry with a concentration of 5%, which was then continuously pumped into the mixed liquid in the biological treatment tank. After several days of continuous feeding and operation, microscopic observation of samples taken from the biological treatment tank clearly showed that the previously dispersed, irregularly shaped activated sludge flocs had largely accumulated on the surface and in the pores of the composite powder carrier particles, forming larger, denser spherical or ellipsoidal particles. This indicates that the dual-sludge micro-ecological framework with confined pores has been initially successfully constructed.

[0056] In one embodiment of the present invention, step S4 includes the following steps: A low-power continuous start-up electrical signal is sent to the bubble generating equipment through an online monitoring and control system; The bubble generator continuously releases a stream of bubbles into the water of the primary treatment system. The continuous flow of air bubbles is guided to penetrate into the internal rigid microchannels of the dual-mud microecological framework, promoting the proliferation of internal functional bacteria and the secretion of adhesive extracellular polymers, thus obtaining an enriched biochemical system.

[0057] In some specific implementations, continuous bubble flow can be selected based on the actual application scenario and cost control requirements, including but not limited to the following two implementations: Implementation Method 1: Continuous bubble flow refers to the conventional bubble flow generated by traditional aeration. In water treatment scenarios with conventional sludge concentrations, conventional aeration can meet the induction and oxygen supply requirements of the dual-sludge micro-ecological framework. This method can effectively utilize existing equipment and significantly reduce the system's operating energy consumption and modification costs.

[0058] Implementation Method Two: The continuous bubble flow is a nanobubble flow, or a mixed bubble flow combining traditional aeration and nanobubbles. Specifically, this application prefers to use nanobubble flow in specific scenarios dealing with high sludge concentrations, such as when the sludge concentration is above 5000 mg / L. Because nanobubbles have a large specific surface area, long residence time, and high mass transfer efficiency, they can effectively overcome the mass transfer resistance in high-concentration sludge systems, ensuring high oxygen demand and thus maintaining stable enrichment of the system.

[0059] Taking the continuous nanobubble flow in Embodiment 2 above as an example, specifically, to drive the exponential bioaccumulation of the underlying functional microbial community, the online monitoring and control system activates the bubble generating device, such as a mobile nanobubble generator in a conventional continuous airflow mode, after determining that the dual-sludge microecological framework has initially formed. This process begins with the online monitoring and control system actively sending a low-power continuous start-up electrical signal to the external frequency conversion control system.

[0060] The low-power continuous start-up electrical signal is a control command designed to achieve a smooth system transition. Its low power is typically set to 20% to 40% of the generator's rated power. The purpose is to provide basic oxygen while avoiding excessive aeration shear force that could damage the initially formed and unstable biofilm structure. After startup, the generator continuously releases a stream of nanobubbles with a characteristic particle size between 50 and 200 nanometers into the water at the bottom of the biological treatment tank.

[0061] The low-power continuous start-up electrical signal is a control command designed to achieve a smooth transition of the system. Its low power is usually set to 20% to 40% of the rated power of the portable nanobubble generator. The purpose is to provide basic oxygen while avoiding excessive aeration shear force that could damage the initially formed and unstable biofilm structure.

[0062] Upon receiving the signal, the external frequency converter control system immediately analyzes and converts it into a specific frequency converter output frequency. This frequency drives the movable nanobubble generator to start with a low initial power and opens its internal air supply pressure regulating valve. After starting, the movable nanobubble generator continuously releases a stream of nanobubbles with a characteristic particle size between fifty and two hundred nanometers into the water at the bottom of the biological tank.

[0063] Characteristic particle size is a key parameter that determines the behavior of nanobubbles. The range of fifty to two hundred nanometers is an optimized result that ensures that the bubbles can effectively penetrate micropores while having sufficient loading capacity and stability in water. Continuous nanobubble flow is a special gas-liquid dispersion system that is different from traditional aeration macrobubbles. It has a long residence time in water and a very large specific surface area, thus ensuring extremely high oxygen mass transfer efficiency.

[0064] The continuous flow of nanobubbles, together with the macrobubbles generated by the existing microporous aeration system in the biological treatment system, forms a synergistic oxygen supply flow. Through an online monitoring and control system, the output ratio of nanobubbles to microporous aeration is dynamically adjusted, maintaining the dissolved oxygen concentration in the anoxic zone of the biological treatment system within the range of 0.2-0.5 mg / L to ensure denitrification, while simultaneously ensuring the dissolved oxygen concentration in the aerobic zone is stably controlled within the range of 2.0-3.0 mg / L. Because nanobubbles within this size range have extremely low buoyancy and significant Brownian motion characteristics, they do not rapidly rise and escape. Instead, they are carried away by the macroscopic and microscopic hydraulic turbulence within the biological treatment tank, thus having the opportunity to penetrate into the internal rigid microchannels of the already formed dual-sludge micro-ecological framework.

[0065] It should be noted that the internal rigid microchannels are rigid porous structures formed by the accumulation of diatomaceous earth particles in the composite powder carrier, which provide shelter for microorganisms. This permeation behavior constitutes a mesoscopic oxygen supply flow to the interior of the framework, directly transporting gaseous oxygen to the core region of the framework, which was previously in a state of mass transfer limitation, thereby increasing the internal oxygen partial pressure.

[0066] Mesoscopic oxygen supply flow is an oxygen supply mode that differs from macroscopic convection and microscopic molecular diffusion. It specifically refers to the process in which oxygen is transported into the interior of porous media ranging from micrometers to millimeters through permeation, using nanobubbles as carriers.

[0067] A sufficient oxygen supply removes the metabolic restrictions on functional bacteria, prompting aerobic functional bacteria such as nitrifying bacteria inside the skeleton to enter an exponential proliferation stage. At the same time, they secrete a large amount of extracellular polymers with strong adhesion. These polymers act as biological adhesives to firmly fix and encapsulate microbial cells on the carrier surface, ultimately leading to a significant increase in the overall effective sludge concentration of the system.

[0068] Adhesive extracellular polymers are mainly gel-like matrices composed of polysaccharides, proteins and other high-molecular-weight substances secreted by microorganisms, and are key components for the formation of stable biofilms; the overall effective sludge concentration of the system refers to the total amount of biologically active microorganisms in the biochemical system, and its increase is a direct reflection of the enhanced treatment capacity of the system.

[0069] In one example of the invention, see Figure 3The sludge concentration increase trend graph shows that after the initial formation of the dual-sludge micro-ecological framework, the online monitoring system measured the mixed liquor suspended solids concentration to rise from the baseline of 3800 mg / L to 4500 mg / L, at which point the system determined that the conditions for starting nano-aeration had been met. The online monitoring and control system immediately sent a low-power continuous start electrical signal to the external frequency converter control system, instructing it to set the operating power of the sixteen sets of portable nanobubble generators, each with a rated power of 18kW, to 30% of their rated power. The external frequency converter control system then adjusted the output of each frequency converter to the corresponding frequency, so that each generator operated at a power of 5.4 kW. The generator array installed at the bottom of the tank began to continuously release a continuous stream of nanobubbles with an average characteristic particle size of 120 nm into the water. Due to the synergistic operation of the nano-aeration system and the existing microporous aeration system, the dissolved oxygen concentration in the aerobic zone of the biological treatment tank rapidly rebounded from a slight decrease of 2.1 mg / L due to the increased sludge concentration, and remained stable within the set process target range of 2.5-3.5 mg / L. Simultaneously, the generator in the anoxic zone operated at extremely low power, controlling the dissolved oxygen in the anoxic zone at approximately 0.3 mg / L. During the subsequent 72 hours of continuous operation, these nanobubbles continuously penetrated into the interior of the dual-sludge micro-ecological framework, providing ample oxygen. Sampling analysis revealed that the average particle size of the framework particles increased and the color deepened due to the thickening of the externally attached extracellular polymers. The overall effective sludge concentration of the system further increased from 4500 mg / L to 6500 mg / L, indicating that the underlying functional microbial community had achieved exponential bioaccumulation.

[0070] In one embodiment of the present invention, step S5 includes the following steps: The air supply to the bubble generator is periodically cut off to form a non-aeration measurement window. Real-time dissolved oxygen electrical signals of the aerobic zone water body within the non-aeration measurement window are collected, aligned and converted according to a unified timestamp, and a real-time dissolved oxygen time series is generated. Within the set analysis sliding time window, calculate the decay slope of the real-time dissolved oxygen time series curve; After converting the curve decay slope to a time unit, it is compared with the critical slope parameter in the preset trigger threshold. When the curve decay slope is greater than or equal to the critical slope parameter, it is determined that the surface of the dual mud micro-ecological skeleton is covered with dense aged extracellular polymers, and a forced pulse cavitation trigger command is generated. The calculation of the decay slope of the real-time dissolved oxygen time series curve includes the following steps: Obtain the total number of data points within the analysis sliding time window, the timestamp corresponding to each data point, and the measured dissolved oxygen concentration value; Calculate the sum of the products of timestamps and dissolved oxygen concentration values, and multiply by the total number of data points to obtain the first product term; The second product term is obtained by multiplying the sum of the timestamps by the sum of the dissolved oxygen concentration values. Calculate the sum of the squares of the timestamps and multiply it by the total number of data points to obtain the third product term; Calculate the square of the sum of timestamps to obtain the fourth product term; Dividing the difference between the first and second product terms by the difference between the third and fourth product terms yields the slope of the curve's decay.

[0071] Specifically, in order to dynamically identify the microscopic mass transfer hindrance caused by the thickening of extracellular polymers and generate a forced pulse cavitation trigger command, the online monitoring and control system periodically issues a command to briefly cut off the air supply at a set high acquisition frequency, such as once per second, to form a non-aeration measurement window. During this window period, oxygen supply interference is eliminated, thereby continuously acquiring real-time dissolved oxygen electrical signals that can truly reflect the net oxygen consumption rate of microorganisms through its dissolved oxygen sensor probes deployed in the aerobic zone of the biological treatment tank.

[0072] The system's internal signal processing unit filters, amplifies, and converts these raw electrical signals to digital, then aligns them according to a unified system timestamp to generate a data stream consisting of a series of timestamps and corresponding dissolved oxygen concentration values—the real-time dissolved oxygen time series. The real-time dissolved oxygen time series is a continuously updated data queue, where each element is a tuple containing a timestamp and a dissolved oxygen concentration value.

[0073] The online monitoring and control system performs online calculations on the latest real-time dissolved oxygen time series data within a pre-set analysis sliding time window. The analysis sliding time window is a data processing interval set to achieve real-time trend analysis; its duration is typically set between 120 and 300 seconds. In this embodiment, based on a scenario requiring rapid response to mass transfer changes, it is set to 180 seconds. This window slides forward over time to ensure that the analysis is always based on the latest system state.

[0074] Specifically, the system uses the least squares linear regression algorithm to calculate the decay slope of the curve represented by the data segment, i.e., the curve decay slope. The curve decay slope is a quantitative indicator that measures the rate of change of dissolved oxygen concentration within a set analysis sliding time window. A negative value indicates that dissolved oxygen is being consumed, and the larger the absolute value, the faster the consumption rate or the lower the mass transfer supply efficiency.

[0075] The system continuously compares the real-time calculated curve decay slope with the critical slope parameter for dissolved oxygen inhibition decay, which is pre-stored in the system's operating baseline. When the curve decay slope value first exceeds (i.e., is greater than or equal to) the critical slope parameter, and the absolute negative value of the slope decreases, approaching zero, indicating a significant slowdown in the effective oxygen consumption decay rate of the microorganisms, the system determines that the surface of the dual-sludge micro-ecological framework is coated with dense, aged extracellular polymers that cause a significant decrease in oxygen mass transfer efficiency. Based on this determination, the online monitoring and control system immediately generates a digital forced pulse cavitation trigger command containing a specific operation code and instantly sends this command to the external frequency conversion control system through the established feedback control closed loop.

[0076] It should be understood that the forced pulse cavitation trigger command is a predefined digital signal whose content uniquely points to one action, namely, requiring the receiver to immediately switch the working mode of the movable nanobubble generator.

[0077] The formula for calculating the slope of the curve attenuation involved is as follows: ; in, The slope of the curve represents the decay rate, expressed in mg / (L⋅s). This represents the total number of data points collected within the set analysis sliding time window; its value is determined by the window duration and the collection frequency. For the first The timestamps corresponding to each data point are in seconds. For timestamp The dissolved oxygen concentration is measured over time, and the unit is mg / L. This formula essentially calculates the slope of the best linearly fitted line for the change in dissolved oxygen concentration over time.

[0078] In one example of the present invention, such as Figure 4 As shown, after several days of continuous operation, the extracellular polymers on the surface of the dual-mud micro-ecological framework gradually thickened. The online monitoring and control system is currently... Dissolved oxygen data is continuously collected at a frequency of 180 seconds, maintaining a set sliding analysis time window. To accurately capture the net oxygen consumption decay rate, the system periodically performs brief gas supply cut-offs, forming a measurement window. Within a certain no-aeration measurement window, the system analysis window covers the period from [a certain point in time]. arrive One hundred and eighty data points were used. Within these one hundred and eighty seconds, the measured dissolved oxygen concentration showed a slow decreasing trend due to inhibited microbial oxygen uptake, for example, decreasing only from an initial 2.50 mg / L to an ending 2.38 mg / L. The online monitoring and control system substituted these one hundred and eighty data points into the above formula to calculate the curve's decay slope. The value is -0.00067 mg / (L⋅s). The system then performs unit conversion to obtain the slope in minutes. The system then compares this calculation result with the critical slope parameter read from the system's baseline route. A comparison is performed. Since -0.040 is greater than -0.05, the preset judgment condition is triggered. The system immediately locks the judgment result, that is, the mass transfer stagnation phenomenon has occurred, and immediately generates a forced pulse cavitation trigger command with the content "EXEC_PULSE_CAVITATION", which is sent to the external frequency converter control system via the Profinet bus to prepare for the next regeneration operation.

[0079] In one embodiment of the present invention, step S6 includes the following steps: Receives a forced pulse cavitation trigger command, cutting off the continuous gas supply from the bubble generator; The bubble generator instantaneously releases a high-pressure pulse of nanobubble clusters. High-pressure pulsed nanobubble clusters are guided to squeeze into the confined channels of the dual-mud micro-ecological framework, triggering cavitation collapse. By utilizing the fluid microjet generated by cavitation collapse, the dense, aged extracellular polymers on the surface of the dual-sludge micro-ecological framework are separated from the aged and deactivated sludge, thus completing the regeneration operation.

[0080] Specifically, in response to the forced pulse cavitation trigger command and to perform micro in-situ regeneration operation, the external frequency converter control system immediately executes the preset mode switching program after receiving the command.

[0081] First, the system forcibly cuts off the normal continuous air supply. Specifically, it uses a signal control cable to instantly close the high-speed electromagnetic pulse valve integrated into the gas-liquid injection end of the movable nanobubble generator, cutting off the release of bubbles and causing internal pressure to accumulate in the equipment.

[0082] Next, after an extremely short pressure storage delay, such as 500 milliseconds, the external frequency conversion control system outputs a trigger electrical pulse, instantly and fully opening the high-speed electromagnetic pulse valve. Utilizing the peak pressure released instantaneously inside, a highly concentrated high-pressure pulse nanobubble cluster is released in a very short time, such as 200 milliseconds.

[0083] High-pressure pulsed nanobubble clusters are special bubble collections generated by the generator under the condition of instantaneous opening and closing of the high-speed electromagnetic pulse valve and pressure storage. The high pressure refers to the internal pressure of the bubble, which is much higher than the standard atmospheric pressure, formed by the sudden change of the pressure field at the moment of release. This is the energy basis for its subsequent strong cavitation effect. The hydrodynamic energy at the moment of release is equivalent to several times that of the conventional continuous gas supply state.

[0084] This swarm of bubbles possesses an internal pressure far exceeding that of conventional bubbles upon generation. However, it is still constrained by the hydrodynamic limitations of the surrounding water's static pressure and flow inertia. Its overall movement is forcibly guided and squeezed into the rigid, confined channels of diatomaceous earth within the dual-mud micro-ecological framework of the reactor. When the high-pressure pulsed nanobubble swarm penetrates deep into the channels and reaches the periphery of the powdered activated carbon particles, due to the drastic changes in the local pressure field and the presence of the solid-liquid interface, these high-pressure bubbles undergo violent, asymmetric cavitation collapse.

[0085] Cavitation collapse refers to the process by which bubbles in a liquid rapidly collapse under external pressure and release enormous energy at the end of the collapse. Asymmetric collapse that occurs near the solid-liquid interface is the key to generating directional microjets.

[0086] The energy of this cavitation process is confined within micron-sized channels formed by a diatomaceous earth framework, and the released energy is mainly converted into one or more high-speed fluid microjets. These fluid microjets are tiny liquid jets generated by cavitation collapse, with speeds reaching hundreds of meters per second. Their diameter is related to the bubble size, and they are the direct force that achieves the ablation.

[0087] These fluid microjets impact the dense, aged extracellular polymers and aged, deactivated sludge attached to the surface of powdered activated carbon with extremely high kinetic energy. Through shearing and peeling, they instantly peel them off from the carrier surface, thereby completing the reset and exposure of the underlying active adsorption sites and realizing the online, in-situ regeneration of the carrier.

[0088] It should be understood that dense, aged extracellular polymers and aged, deactivated sludge are the root causes of the decline in mass transfer efficiency and biological activity of the dual-sludge micro-ecological framework. Their composition is complex and they have high adhesion. On the other hand, the active adsorption sites are the microporous structures and chemical functional groups with adsorption capacity inside and on the surface of powdered activated carbon materials. They are the basis for their purification function. When they are covered by the stripped material, they are deactivated, and when they are re-exposed, they are regenerated.

[0089] In one example of this invention, upon receiving a forced pulse cavitation trigger command containing the content "EXEC_PULSE_CAVITATION", the external frequency conversion control system immediately sends a cutoff command to sixteen movable nanobubble generators via control cables, closing the high-speed electromagnetic pulse valves at their front ends. The continuous 5.4kW conventional air supply is cut off within 50 ms, and internal pressure accumulation begins. Subsequently, after a 500 ms pressure accumulation delay, the control system executes a pulse release procedure, sending a fully open electrical signal to the pulse valve. The accumulated high-pressure potential energy is used to instantly overcome water resistance, maintaining the valve fully open for 200 ms. During this period, the sixteen generators simultaneously spray high-pressure pulse nanobubble clusters into the water. One of the dual-mud micro-ecological framework particles contains a confined channel with a diameter of 2 μm, into which a high-pressure pulse nanobubble cluster is squeezed. The bubbles collapse upon contact with the powdered activated carbon particles on the inner wall of the channel, generating a fluid microjet pointing towards the carbon surface with a velocity as high as 150 m / s. The impact force of this jet acts on an area of ​​approximately 1 μm... 2 The dense, aged, yellowish-brown extracellular polymeric material covering the surface of activated carbon is instantly washed away and stripped from the black carbon substrate. This process occurs simultaneously within the hundreds of millions of micro-ecological skeletons throughout the reactor. After the 200 ms pulse ends, the external frequency conversion control system automatically returns to the normal continuous gas supply mode, re-driving the generator at 5.4 kW to produce nanobubble flow to maintain dissolved oxygen. The entire process, from receiving the command to completing regeneration and resuming normal operation, takes less than one second, thus completing the in-situ regeneration of the entire biochemical system carrier.

[0090] In one embodiment of the present invention, step S7 includes the following steps: Acquire online suspended solids concentration data and real-time sludge settling index values ​​during regeneration operations and system response; Based on online suspended solids concentration data and real-time sludge settling index values, the valve opening of the sludge return pump unit is dynamically adjusted to maintain the sludge return operation ratio within the preset safe and stable range. The dense, aged extracellular polymers that are stripped off are guided into the anoxic aquatic environment along with the returned sludge, where they are transformed into an endogenous supplementary carbon source to support the denitrification reaction. After confirming that the regeneration operation has been completed and that the online suspended solids concentration data and real-time sludge settling index values ​​have returned to stability, switch the addition mode of the composite powder carrier. The dosage of the composite powder carrier was adjusted from the initial dosage gradient to a steady-state wear compensation dosage mode; By maintaining the effective sludge concentration in the system through steady-state addition, a steady-state expansion biochemical system is output that meets the predetermined hydraulic expansion index and the bottom pollutant degradation load standard.

[0091] Specifically, in order to complete the closed-loop monitoring and steady-state control of the micro-in-situ regeneration operation, the online monitoring and control system immediately switches its monitoring focus after the forced pulse cavitation trigger command is issued, and begins to collect online suspended solids concentration data of the water at the inlet of the secondary sedimentation tank at high frequency, and performs joint feedforward analysis in combination with the real-time sludge settling index value of the mixed liquor in the biological treatment tank.

[0092] Among them, the real-time sludge settling index value usually refers to the sludge volume index, which is a comprehensive indicator for measuring the settling and thickening performance of activated sludge. It is automatically measured by an online sludge settling meter, and the unit is mL / g.

[0093] At the same time, the system triggers two serialized boot and control tasks.

[0094] The first task is to guide the endogenous transformation reaction of the detached material. Specifically, the online monitoring and control system dynamically adjusts the valve opening and pump speed of the sludge return pump unit based on the high-frequency online suspended solids concentration data and the periodically updated real-time sludge settling index values, combined with the sludge level gauge data of the secondary settling tank. This adjusts the sludge return operation ratio, with the core objective of maintaining this ratio within a preset safe and stable range to ensure the hydraulic stability of the system and prevent sludge runoff from the secondary settling tank caused by the instantaneous change in the properties of the mixed liquor after pulse stripping.

[0095] Specifically, the online monitoring and control system has a built-in dynamic proportional control law model based on SVI deviation to calculate the target sludge return ratio for the next cycle. : ; In the formula, This represents the current sludge recirculation operation ratio; This refers to real-time sludge settling index values; The upper limit threshold of the preset safe and stable range, such as 120 mL / g; This is the proportional control gain coefficient, typically ranging from 0.5% to 1.5% per (mL / g). When within the safe range, the control system maintains the original return ratio; when regeneration stripping causes the sludge to temporarily loosen, When the upper limit threshold is exceeded, the computer calculates the result based on the above equation. The positive increment is converted into an analog signal to drive the frequency converter to increase the speed of the return pump.

[0096] The sludge return operation ratio refers to the ratio of the return sludge flow rate to the influent flow rate, which is one of the key parameters for the operation and control of the activated sludge process. The safe and stable range is an empirical range used to ensure that the sludge can settle effectively in the secondary sedimentation tank without being lost. For this system, this range is usually set at a sludge settling index of 80-120 mL / g.

[0097] During this process, the dense, aged extracellular polymers stripped off by the fluid microjet will dissolve and enter the anoxic zone of the biological system along with the regulated return sludge. The organic components contained therein will be utilized by the denitrifying bacteria in the area, thereby transforming them into an endogenous supplementary carbon source necessary to support the denitrification reaction step.

[0098] Endogenous carbon sources refer to organic carbon derived from the metabolic products of microorganisms or the lysates of dead cells within the system. Unlike exogenous carbon sources such as methanol and sodium acetate, which require additional addition, using endogenous carbon sources can significantly reduce operating costs.

[0099] The second task is to perform steady-state compensation control of the carrier dosage. After confirming that the microscopic in-situ regeneration operation has been completed and the system has returned to stability, the online monitoring and control system automatically switches the addition mode of the composite powder carrier, adjusting it from the initial addition gradient in the start-up phase to the steady-state wear compensation addition mode.

[0100] The dosage in steady-state wear compensation dosing mode is a dosage value that is much lower than the starting dosage and is used to maintain the total balance of the carrier in the system. It is set based on compensating for the slight wear and loss of the carrier caused by pump shearing, particle collision and other effects. According to a large number of engineering practice statistics, this dosage is usually set in the range of 2-15 mg / (L⋅d).

[0101] Ultimately, through the aforementioned synergistic regulation, the entire biochemical system reaches a new, high-concentration steady state, outputting a steady-state expanded-capacity biochemical system that meets the predetermined hydraulic expansion targets and bottom pollutant degradation load standards. In summary, a steady-state expanded-capacity biochemical system refers to the highly efficient state exhibited by the wastewater treatment plant after completing all the process steps of this invention, characterized by stronger treatment capacity and more stable operation.

[0102] In one example of the present invention, combined with Figure 5 The dynamic control process of the reflux ratio shown illustrates that after the micro-in-situ regeneration operation is completed, the online monitoring and control system immediately initiates joint monitoring of the online suspended solids concentration and real-time sludge settling index values ​​of the mixed liquor at the aerobic tank outlet. Due to the shedding of a large amount of dense, aged extracellular polymers, the sludge flocs temporarily become loose. The online suspended solids concentration sensor quickly detects abnormal fluctuations in localized detached material, and the subsequently updated real-time sludge settling index value slightly increases from 115 mL / g before regeneration to 125 mL / g, exceeding the safe and stable range of 80-120 mL / g. The system determines there is a potential risk of sludge runoff and immediately executes the control program, invoking the dynamic proportional control law model. The current reflux ratio is known. The system selects a proportional gain coefficient of 60%. The value is 1.0%. Substituting this into the excess limit indicator, the target reflux ratio is calculated as follows: The system then output control commands to increase the valve opening of the return pump, raising the sludge return operation ratio to 65% to accelerate the return of sludge from the secondary settling tank to the biological treatment tank, reduce the sludge level in the secondary settling tank, and prevent sludge loss. The stripped dense, aged extracellular polymers entered the anoxic zone along with the increased return sludge. The online nitrate analyzer in this zone showed that the nitrate concentration decreased by 15% over the next two hours, indicating that these stripped materials were effectively utilized as an endogenous carbon source, improving denitrification efficiency. After a period of cyclical adjustment, the online suspended solids concentration stabilized, and the real-time sludge settling index value dropped and stabilized at 95 mL / g. At this point, the system determined that it had stabilized and immediately executed the second task, switching the composite powder carrier addition mode to steady-state mode. The original initial addition gradient, i.e., a total addition of 29.17 kg / h, was replaced by new commands. The new compensation dose was set to 12 mg / (L⋅d), and the system calculated the corresponding total addition amount as follows: The system issued new instructions to both feeders, adjusting their feed rate to 3.5 kg / h. At this point, the system entered a long-term stable operation phase. Figure 6 The comparison results show that its total effective sludge concentration remained stable at 7500 mg / L, and it can stably treat up to 34000 m³. 3 With an influent flow rate of / d, the treatment capacity has been increased by 70% compared to the original design capacity, and a steady-state expansion biochemical system has been successfully constructed.

[0103] See appendix Figure 7 The present invention also proposes a control system based on in-situ expansion of a wastewater treatment plant without interrupting water supply, comprising the following modules: The baseline route generation module is used to obtain the measured operating parameters of the native system and generate a system operating baseline route that includes a preset trigger threshold and an initial gradient. The closed-loop system construction module is used to call the system's operating baseline route and establish a feedback control closed loop consisting of an online monitoring and control system, material feeding equipment, and bubble generating equipment. The micro-ecological framework construction module is used to drive the material feeding equipment through feedback control closed loop, inject the composite powder carrier into the original system according to the initial feeding gradient, and generate the dual mud micro-ecological framework. The bioaccumulation drive module is used to control the bubble generating device to output a continuous bubble flow to the dual-mud micro-ecological framework to obtain an enriched biochemical system. The mass transfer lag identification module is used to acquire the real-time dissolved oxygen time series of the enrichment biochemical system, calculate its curve decay slope, compare the curve decay slope with the preset trigger threshold, and generate a forced pulse cavitation trigger command. The in-situ physical regeneration module is used to respond to the forced pulse cavitation trigger command, control the bubble generating device to release high-pressure pulse nanobubble clusters to the dual mud micro-ecological framework, and perform regeneration operation; The steady-state compensation control module is used to acquire online suspended solids concentration data and real-time sludge settling index values ​​during regeneration operations and system response, dynamically adjust the sludge return operation ratio, and adjust the dosage of composite powder carrier after confirming that the regeneration operation has been completed and the system has returned to stability, thereby obtaining a steady-state expanded biochemical system.

[0104] Each of the modules can be implemented in whole or in part through software, hardware, or a combination thereof. It supports hardware embedded in or independent of the processor in the computer device, and also supports software stored in the memory of the computer device, so that the processor can call and execute the operations corresponding to each of the above modules.

[0105] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included within the protection scope of the present invention.

Claims

1. A control method based on in-situ expansion of a wastewater treatment plant without interrupting water supply, characterized in that: Includes the following steps: S1. Obtain the measured operating parameters of the native system and generate a system operating baseline route that includes a preset trigger threshold and an initial gradient. S2. Call the system's baseline route and establish a feedback control closed loop consisting of the online monitoring and control system, material feeding equipment, and bubble generating equipment; S3. Drive the material feeding equipment through feedback control closed loop, inject the composite powder carrier into the original system according to the initial feeding gradient, and generate a dual mud micro-ecological skeleton. S4. Control the bubble generating equipment to output a continuous bubble flow to the dual mud micro-ecological framework to obtain an enriched biochemical system; S5. Obtain the real-time dissolved oxygen time series of the enrichment biochemical system, calculate its curve decay slope, compare the curve decay slope with the preset trigger threshold, and generate a forced pulse cavitation trigger command. S6. Responding to the forced pulse cavitation trigger command, control the bubble generating device to release high-pressure pulse nanobubble clusters to the dual mud micro-ecological framework to perform regeneration operation; S7. Obtain online suspended solids concentration data and real-time sludge settling index values ​​during regeneration operation and system response, dynamically adjust the sludge return operation ratio, and adjust the dosage of composite powder carrier after confirming that the regeneration operation has been completed and the system has returned to stability, to obtain a steady-state expanded biochemical system.

2. The control method based on in-situ expansion of a wastewater treatment plant without interrupting water supply, as described in claim 1, is characterized in that... Step S1 includes the following steps: Acquire measured sludge concentration data, dynamic dissolved oxygen data, influent flow rate data, influent water quality characterization parameters, and effluent water quality characterization parameters of the original treatment system; Based on measured sludge concentration data and effluent quality characterization parameters, a preset trigger threshold including a critical slope parameter is set. The effective influent load is calculated based on influent flow rate data and influent water quality characterization parameters. The initial dosing gradient is set by comparing the effective influent load with dynamic dissolved oxygen data. By integrating the preset trigger threshold with the initial gradient, a baseline route for system operation is generated.

3. The control method based on in-situ expansion of a wastewater treatment plant without interrupting water supply, as described in claim 1, is characterized in that... Step S2 includes the following steps: Bubble generators are installed at the bottom of the aerobic and anoxic zones of the original system, and material feeding devices are installed at the inlet and outlet. An online monitoring and control system integrating multi-source data sensing probes is deployed within a native system; An online monitoring and control system is established and electrically communicated with both the bubble generating equipment and the material feeding equipment to generate a feedback control closed loop.

4. The control method based on in-situ expansion of a wastewater treatment plant without interrupting water supply, as described in claim 1, is characterized in that... Step S3 includes the following steps: A composite powder carrier with a spatially rigid porous channel structure was prepared by obtaining diatomaceous earth dry powder and powdered activated carbon and blending them. By controlling the feedback loop to output the initial start command, the material feeding equipment is driven to continuously inject the composite powder carrier into the bottom mixture of the original chemical system according to the initial feeding gradient. The suspended activated sludge in the induced native system aggregates into the confined space of the composite powder carrier, generating a dual-sludge micro-ecological framework.

5. The control method based on in-situ expansion of a wastewater treatment plant without interrupting water supply, as described in claim 1, is characterized in that... Step S4 includes the following steps: A low-power continuous start-up electrical signal is sent to the bubble generating equipment through an online monitoring and control system; The bubble generator continuously releases a stream of bubbles into the water of the primary treatment system. The continuous flow of air bubbles is guided to penetrate into the internal rigid microchannels of the dual-mud microecological framework, promoting the proliferation of internal functional bacteria and the secretion of adhesive extracellular polymers, thus obtaining an enriched biochemical system.

6. The control method based on in-situ expansion of a wastewater treatment plant without interrupting water supply, as described in claim 1, is characterized in that... Step S5 includes the following steps: The air supply to the bubble generator is periodically cut off to form a non-aeration measurement window. Real-time dissolved oxygen electrical signals of the aerobic zone water body within the non-aeration measurement window are collected, aligned and converted according to a unified timestamp, and a real-time dissolved oxygen time series is generated. Within the set analysis sliding time window, calculate the decay slope of the real-time dissolved oxygen time series curve; After converting the curve decay slope to a time unit, it is compared with the critical slope parameter in the preset trigger threshold. When the curve decay slope is greater than or equal to the critical slope parameter, it is determined that the surface of the dual mud micro-ecological skeleton is covered with dense aged extracellular polymers, and a forced pulse cavitation trigger command is generated.

7. The control method based on in-situ expansion of a wastewater treatment plant without interrupting water supply, as described in claim 6, is characterized in that... Calculating the decay slope of the real-time dissolved oxygen time series curve includes the following steps: Obtain the total number of data points within the analysis sliding time window, the timestamp corresponding to each data point, and the measured dissolved oxygen concentration value; Calculate the sum of the products of timestamps and dissolved oxygen concentration values, and multiply by the total number of data points to obtain the first product term; The second product term is obtained by multiplying the sum of the timestamps by the sum of the dissolved oxygen concentration values. Calculate the sum of the squares of the timestamps and multiply it by the total number of data points to obtain the third product term; Calculate the square of the sum of timestamps to obtain the fourth product term; Dividing the difference between the first and second product terms by the difference between the third and fourth product terms yields the slope of the curve's decay.

8. The control method based on in-situ expansion of a wastewater treatment plant without interrupting water supply, as described in claim 1, is characterized in that... Step S6 includes the following steps: Receives a forced pulse cavitation trigger command, cutting off the continuous gas supply from the bubble generator; The bubble generator instantaneously releases a high-pressure pulse of nanobubble clusters. High-pressure pulsed nanobubble clusters are guided to squeeze into the confined channels of the dual-mud micro-ecological framework, triggering cavitation collapse. By utilizing the fluid microjet generated by cavitation collapse, the dense, aged extracellular polymers on the surface of the dual-sludge micro-ecological framework are separated from the aged and deactivated sludge, thus completing the regeneration operation.

9. The control method based on in-situ expansion of a wastewater treatment plant without interrupting water supply, as described in claim 1, is characterized in that... Step S7 includes the following steps: Acquire online suspended solids concentration data and real-time sludge settling index values ​​during regeneration operations and system response; Based on online suspended solids concentration data and real-time sludge settling index values, the valve opening of the sludge return pump unit is dynamically adjusted to maintain the sludge return operation ratio within the preset safe and stable range. The dense, aged extracellular polymers that are stripped off are guided into the anoxic aquatic environment along with the returned sludge, where they are transformed into an endogenous supplementary carbon source to support the denitrification reaction.

10. A control system for in-situ expansion of a wastewater treatment plant without interrupting water supply, characterized in that: Includes the following modules: The baseline route generation module is used to obtain the measured operating parameters of the native system and generate a system operating baseline route that includes a preset trigger threshold and an initial gradient. The closed-loop system construction module is used to call the system's operating baseline route and establish a feedback control closed loop consisting of an online monitoring and control system, material feeding equipment, and bubble generating equipment. The micro-ecological framework construction module is used to drive the material feeding equipment through feedback control closed loop, inject the composite powder carrier into the original system according to the initial feeding gradient, and generate the dual mud micro-ecological framework. The bioaccumulation drive module is used to control the bubble generating device to output a continuous bubble flow to the dual-mud micro-ecological framework to obtain an enriched biochemical system. The mass transfer lag identification module is used to acquire the real-time dissolved oxygen time series of the enrichment biochemical system, calculate its curve decay slope, compare the curve decay slope with the preset trigger threshold, and generate a forced pulse cavitation trigger command. The in-situ physical regeneration module is used to respond to the forced pulse cavitation trigger command, control the bubble generating device to release high-pressure pulse nanobubble clusters to the dual mud micro-ecological framework, and perform regeneration operation; The steady-state compensation control module is used to acquire online suspended solids concentration data and real-time sludge settling index values ​​during regeneration operations and system response, dynamically adjust the sludge return operation ratio, and adjust the dosage of composite powder carrier after confirming that the regeneration operation has been completed and the system has returned to stability, thereby obtaining a steady-state expanded biochemical system.

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