Sludge degradation synergistic septic tank sewage treatment deep purification system and method

Abstract

The invention provides a deep purification system and a deep purification method for sewage treatment of a septic tank with synergy of sludge degradation. Comprising a graded anaerobic reaction unit for performing graded conversion treatment on organic pollutants in sewage; the sludge synergistic degradation unit is used for performing floc deconstruction treatment on the deposited sludge in the sludge activation reaction space; the micro-aerobic enhanced reaction unit is used for forming a facultative reaction environment under a controlled dissolved oxygen condition, so that microbial communities in the returned sludge execute a biological conversion reaction on nitrogen pollutants; the deep purification unit is used for performing multi-stage filtration and adsorption treatment on the sewage; and the circulating regulation and control unit is used for regulating the sludge conveying flow in the sludge backflow path, the oxygen supply intensity in the micro-aerobic enhanced reaction unit and the backflow proportion of the deep purification unit based on the operation parameters so as to execute coordinated regulation of the operation parameters of the system. The sludge degradation efficiency can be improved, the nitrogen removal capacity is enhanced, and the operation stability of the system is improved.

Description

Technical Field

[0001] This application relates to the field of wastewater treatment technology, and in particular to a deep purification system and method for septic tank wastewater treatment that promotes sludge degradation. Background Technology

[0002] With the increasing demand for decentralized rural domestic sewage treatment and small-scale sewage treatment in suburban areas, septic tanks remain one of the most widely used basic sewage treatment facilities. Traditional septic tanks mainly remove suspended solids and some organic matter from sewage through sedimentation separation and anaerobic fermentation. They are characterized by simple structure, low construction cost, and low operation and maintenance requirements, and are therefore widely used in scenarios without centralized pipe networks or in decentralized sewage treatment settings. However, with the continuous improvement of water environment governance standards, relying solely on traditional septic tanks for sewage treatment is no longer sufficient to meet the control requirements for pollutants such as nitrogen and phosphorus. Therefore, how to improve the treatment capacity of septic tanks while maintaining their simple structure and stable operation has become an important research direction in this field.

[0003] In existing technologies, constructed wetlands, biofilters, or other advanced treatment units are typically installed at the rear end of septic tanks to improve wastewater treatment efficiency. Additionally, some technologies enhance organic matter degradation and nitrogen conversion by adding microbial agents or aeration devices. However, most of these solutions are still based on traditional septic tank structures, leading to long-term sludge deposition at the bottom, gradual decrease in sludge activity, and problems such as sludge aging and reduced anaerobic reaction efficiency. Furthermore, existing systems typically lack mechanisms for sludge recycling and microbial activity regulation, making it difficult to achieve synergistic effects between sludge degradation and pollutant removal. Moreover, existing technologies lack effective synergistic control methods for the operation and regulation of anaerobic, microaerobic, and advanced purification units, limiting the overall system efficiency and stability. Therefore, how to construct a septic tank wastewater treatment advanced purification system that can achieve synergistic enhancement of sludge degradation and form a synergistic operation mechanism among multi-stage reaction units has become a pressing technical problem to be solved in this field. Summary of the Invention

[0004] In view of this, the present application provides a septic tank wastewater treatment deep purification system and method with sludge degradation synergy, in order to solve the problems of low sludge activity, insufficient nitrogen removal capacity and poor system synergy control capacity in the prior art.

[0005] The first aspect of this application provides a septic tank wastewater treatment deep purification system with sludge degradation synergy, comprising: a staged anaerobic reaction unit for receiving pretreated wastewater and constructing a stepwise anaerobic reaction path in a hydrolysis acidification zone, an acidification zone, and a methanogenesis zone set along the water flow direction to perform staged transformation treatment on organic pollutants in the wastewater; a sludge synergy degradation unit for extracting deposited sludge from the bottom of the staged anaerobic reaction unit and transporting it to a sludge activation reaction space, performing floc decomposition treatment on the deposited sludge in the sludge activation reaction space, and contacting the deposited sludge with a microbial carrier loaded with functional bacteria to generate activated sludge, and returning the activated sludge to the staged anaerobic reaction unit to participate in the anaerobic degradation process; and a microaerobic enhanced reaction unit. The system consists of three main components: a primary anaerobic digester, a secondary anaerobic digester, and a facultative reaction environment. The primary anaerobic digester receives wastewater treated by the staged anaerobic digester and creates a controlled dissolved oxygen environment to enable the microbial community in the returned sludge to perform biotransformation reactions on nitrogen pollutants. The secondary anaerobic digester receives wastewater treated by the microaerobic enhanced digester and performs multi-stage filtration and adsorption treatment on the wastewater through a sequentially arranged bio-attached filter layer, an ion exchange adsorption layer, and a carbon source release layer. The cyclic control unit collects operating parameters from the staged anaerobic digester, the microaerobic enhanced digester, and the secondary anaerobic digester, and adjusts the sludge flow rate in the sludge return path, the oxygen supply intensity in the microaerobic enhanced digester, and the return ratio in the secondary anaerobic digester based on these parameters to perform coordinated regulation of the system's operating parameters.

[0006] The second aspect of this application provides a method for deep purification of septic tank wastewater treatment based on the sludge degradation synergy of the first aspect system, comprising: receiving pretreated wastewater and introducing the wastewater into a staged anaerobic reaction unit, so that the wastewater sequentially passes through a hydrolysis acidification zone, an acid production zone and a methanogenic zone set along the water flow direction to perform stepwise anaerobic conversion treatment on the organic pollutants in the wastewater; extracting the deposited sludge from the bottom of the staged anaerobic reaction unit and transporting it to a sludge activation reaction space, performing floc destructive treatment on the deposited sludge in the sludge activation reaction space, and making the deposited sludge contact and react with a microbial carrier loaded with functional bacteria to generate activated sludge, and returning the activated sludge to the staged anaerobic reaction unit; Wastewater treated by the staged anaerobic reactor is introduced into the micro-aerobic enhanced reactor to create a facultative reaction environment under controlled dissolved oxygen conditions, enabling the microbial community in the returned sludge to perform biotransformation reactions on nitrogenous pollutants in the wastewater. Wastewater treated by the micro-aerobic enhanced reactor is then introduced into the deep purification unit, where it sequentially passes through a bio-attached filter layer, an ion exchange adsorption layer, and a carbon source release layer, undergoing multi-stage filtration and adsorption treatment. Operating parameters are collected from the staged anaerobic reactor, the micro-aerobic enhanced reactor, and the deep purification unit, and the sludge transport flow rate in the sludge return path, the oxygen supply intensity in the micro-aerobic enhanced reactor, and the return ratio in the deep purification unit are adjusted based on these parameters.

[0007] The above-described technical solutions adopted in the embodiments of this application can achieve the following beneficial effects: The system comprises a tiered anaerobic reactor unit, which receives pretreated wastewater and constructs a progressively anaerobic reaction pathway within hydrolysis-acidification, acidification, and methanogenesis zones along the water flow direction to perform tiered transformation of organic pollutants in the wastewater. A sludge co-degradation unit extracts deposited sludge from the bottom of the tiered anaerobic reactor unit and transports it to a sludge activation reaction space. Within this space, the deposited sludge undergoes flocculent decomposition treatment and comes into contact with a microbial carrier loaded with functional bacteria to generate activated sludge. This activated sludge is then returned to the tiered anaerobic reactor unit to participate in the anaerobic degradation process. A microaerobic enhancement unit receives wastewater treated by the tiered anaerobic reactor unit. Wastewater is treated under controlled dissolved oxygen conditions to create a facultative reactive environment, enabling the microbial community in the returned sludge to perform biotransformation reactions on nitrogen pollutants. A deep purification unit receives the wastewater treated by the microaerobic-enhanced reaction unit and performs multi-stage filtration and adsorption treatment through a sequentially arranged bio-attached filter layer, ion exchange adsorption layer, and carbon source release layer. A circulation control unit collects operating parameters from the staged anaerobic reaction unit, microaerobic-enhanced reaction unit, and deep purification unit, and adjusts the sludge flow rate in the sludge return path, the oxygen supply intensity in the microaerobic-enhanced reaction unit, and the return ratio of the deep purification unit based on these parameters to achieve coordinated regulation of system operating parameters. This application can improve sludge degradation efficiency, enhance nitrogen removal capacity, and improve system operational stability. Attached Figure Description

[0008] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0009] Figure 1 This is a schematic diagram of the architecture of a septic tank wastewater treatment deep purification system in a real-world scenario provided in the embodiments of this application; Figure 2 This is a schematic diagram of the structural composition of the sludge degradation synergistic deep purification system for septic tank wastewater treatment provided in the embodiments of this application; Figure 3 This is a schematic flowchart of the septic tank wastewater treatment deep purification method with sludge degradation synergy provided in the embodiments of this application. Detailed Implementation

[0010] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of this application. However, those skilled in the art will understand that this application may also be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods have been omitted so as not to obscure the description of this application with unnecessary detail.

[0011] In existing technologies, septic tanks typically rely on sedimentation and anaerobic fermentation to reduce suspended solids and some organic matter in wastewater. When necessary, advanced treatment units such as constructed wetlands and biological filters are connected in series at the downstream end to improve effluent quality. Some solutions also enhance the septic tank treatment process by adding microbial agents or installing aeration devices. Overall, these solutions still rely on traditional septic tanks as the core, and the treatment chain is mostly a combination of "anaerobic sedimentation + end-of-pipe reinforcement."

[0012] In the aforementioned existing technologies, the sedimented sludge remains at the bottom of the tank for a long time, and the sludge activity decreases over time and is prone to sludge aging. The anaerobic staged transformation is unstable, resulting in insufficient continuous reduction capacity of dissolved organic matter. At the same time, the removal of nitrogen pollutants such as ammonia nitrogen and total nitrogen depends on external units or empirical operation, and lacks a biological transformation pathway coupled with the state of sludge inside the septic tank. In addition, there is a lack of linkage and control mechanism between multi-level units for key operating parameters, and it is difficult to coordinate and match sludge return, oxygen supply intensity and deep purification return ratio, which limits the long-term stable operation and comprehensive purification capacity of the system.

[0013] In view of the problems existing in the prior art, this application proposes a sludge degradation synergistic deep purification system for septic tank wastewater treatment: A hydrolysis acidification zone, an acid production zone, and a methanogenesis zone are set up along the water flow direction within a staged anaerobic reaction unit to construct a step-by-step anaerobic reaction path; a sludge synergistic degradation unit is set up to extract deposited sludge from the bottom of the staged anaerobic reaction unit and transport it to a sludge activation reaction space, where the deposited sludge undergoes floc decomposition treatment and is brought into contact with a microbial carrier loaded with functional bacteria to generate activated sludge, which is then returned to the staged anaerobic reaction unit to participate in the anaerobic degradation process; a micro-aerobic enhancement reaction unit is set up to create a facultative reaction environment under controlled dissolved oxygen conditions, enabling the microbial community in the returned sludge to perform biotransformation of nitrogen pollutants; a deep purification unit is set up to allow the treated water to undergo multi-stage filtration and adsorption by sequentially passing through a bio-attached filter media layer, an ion exchange adsorption layer, and a carbon source release layer; and a circulation control unit is set up to collect operating parameters and, based on these parameters, adjust the sludge transport flow rate, oxygen supply intensity, and return ratio to form a synergistic operation path.

[0014] Based on the above technical solution, this application can improve sludge degradation efficiency, enhance nitrogen removal capacity, and improve system operation stability.

[0015] Before providing a detailed description of the embodiments of this application, the system architecture and working process of the septic tank sewage treatment deep purification system of this application in a real-world scenario will first be described in conjunction with the accompanying drawings and embodiments. Figure 1 This is a schematic diagram of the architecture of a septic tank wastewater treatment deep purification system in a real-world scenario provided in the embodiments of this application, such as... Figure 1 As shown, the system may specifically include the following components: a staged anaerobic reaction unit, a sludge co-degradation unit, a micro-aerobic enhanced reaction unit, a deep purification unit, and a circulation control unit.

[0016] The staged anaerobic reactor unit is used to perform staged anaerobic treatment on the domestic sewage entering the system. Inside this unit, a hydrolysis-acidification zone, an acid-producing zone, and a methanogenic zone are sequentially arranged along the water flow direction. Through multi-stage anaerobic reaction spaces, a progressive anaerobic reaction pathway is constructed, allowing the sewage entering the system to gradually complete the decomposition and transformation of organic matter in different anaerobic environments. In the hydrolysis-acidification zone, large organic molecules are converted into intermediate products such as volatile fatty acids under the action of hydrolytic bacteria. The sewage then enters the acid-producing zone, where it is further converted into small organic acids under the action of acid-producing bacteria. Finally, it enters the methanogenic zone, where anaerobic metabolic reactions are completed under the action of methanogenic bacteria. Simultaneously, sludge is formed at the bottom of the staged anaerobic reactor unit, and some of this sludge is extracted and transported to the sludge co-degradation unit.

[0017] The sludge co-degradation unit is used to activate deposited sludge and establish a sludge recycling pathway. This unit contains a sludge activation reaction space where flocculent decomposition and activation treatment is performed on the deposited sludge from the bottom of the staged anaerobic reactor. This reactivates the microbial community in the deposited sludge, allowing it to react with a microbial carrier loaded with functional bacteria, thereby generating activated sludge. A portion of the generated activated sludge is returned to the staged anaerobic reactor to participate in the anaerobic degradation process, while the remainder can be transported to subsequent reaction units, thus forming a sludge recycling and sludge co-degradation mechanism within the system.

[0018] The microaerobic-enhanced reaction unit is used to perform microaerobic-enhanced treatment on wastewater after it has been treated by the staged anaerobic reaction unit. This unit is equipped with a micro-aeration structure, which generates a microbubble mixture flow by supplying a controllable volume of air and maintaining a controlled dissolved oxygen environment in the reaction space, thus placing the reaction zone under facultative reaction conditions. In this facultative reaction environment, the microbial community in the returned sludge can perform biotransformation reactions on nitrogenous pollutants in the wastewater, thereby achieving further transformation and treatment of nitrogenous pollutants. The wastewater treated by the microaerobic-enhanced reaction unit is then transported to the advanced purification unit.

[0019] The advanced purification unit is used for further filtration and adsorption treatment of wastewater. Internally, this unit sequentially comprises a bio-attached filter media layer, an ion exchange adsorption layer, and a carbon source release layer. Wastewater first passes through the bio-attached filter media layer, where a bio-attachment interface forms on the porous biological carrier surface, allowing dissolved pollutants to contact and react with the attached microbial community. It then enters the ion exchange adsorption layer, where functionalized ion exchange materials adsorb ammonia nitrogen and dissolved ions from the wastewater. Finally, it enters the carbon source release layer, where slow-release solid carbon source materials continuously release carbon into the water, providing substrates for the biological reactions within the system, thereby further enhancing pollutant removal capacity. Wastewater treated by the advanced purification unit ultimately meets discharge standards.

[0020] The circulation control unit is used to regulate the system's operating status. This unit establishes signal connections with the sludge co-degradation unit, the micro-aerobic enhancement reaction unit, and the deep purification unit. By collecting operating parameters from the system, it adjusts the sludge return flow rate in the sludge return path, and simultaneously regulates the oxygen supply intensity in the micro-aerobic enhancement reaction unit and the return ratio in the deep purification unit, thereby achieving coordinated operation among the various treatment units within the system. Through the above structural design and operating mode, the septic tank wastewater treatment deep purification system of this application can achieve sludge circulation activation, anaerobic degradation enhancement, and deep purification treatment within the same system structure, thus forming a stable multi-stage coordinated treatment process.

[0021] The specific components and functions of the sludge degradation synergistic septic tank wastewater treatment deep purification system provided in this application will be described in detail below with reference to the accompanying drawings and specific embodiments. Figure 2 This is a schematic diagram of the structural composition of the sludge degradation synergistic septic tank wastewater treatment deep purification system provided in the embodiments of this application, as shown below. Figure 2 As shown, the system may specifically include the following components: The graded anaerobic reaction unit 201 is used to receive pretreated wastewater and construct a graded anaerobic reaction path in the hydrolysis acidification zone, acid production zone and methanogenic zone set along the water flow direction to perform graded conversion treatment on organic pollutants in wastewater. The sludge co-degradation unit 202 is used to extract the deposited sludge from the bottom of the graded anaerobic reaction unit and transport it to the sludge activation reaction space. In the sludge activation reaction space, the deposited sludge is subjected to floc destructive treatment, and the deposited sludge is brought into contact with the microbial carrier loaded with functional bacteria to generate activated sludge. The activated sludge is then returned to the graded anaerobic reaction unit to participate in the anaerobic degradation process. The micro-aerobic enhanced reaction unit 203 is used to receive wastewater treated by the staged anaerobic reaction unit and to form a facultative reaction environment under controlled dissolved oxygen conditions, so that the microbial community in the returned sludge can carry out biotransformation reactions on nitrogen pollutants. The deep purification unit 204 is used to receive wastewater after it has been treated by the micro-oxygen enhanced reaction unit, and to perform multi-stage filtration and adsorption treatment on the wastewater through a biological attachment filter media layer, an ion exchange adsorption layer and a carbon source release layer arranged in sequence. The circulation control unit 205 is used to collect the operating parameters of the staged anaerobic reaction unit, the micro-aerobic enhanced reaction unit and the deep purification unit, and adjust the sludge transport flow rate in the sludge return path, the oxygen supply intensity in the micro-aerobic enhanced reaction unit and the return ratio of the deep purification unit based on the operating parameters, so as to perform coordinated adjustment of the system operating parameters.

[0022] In some embodiments, the staged anaerobic reaction unit is specifically used for: By setting up flow guide baffles and bottom connecting channels, the staged anaerobic reaction unit is divided into a hydrolysis acidification zone, an acid production zone, and a methanogenic zone that are connected in sequence, so as to construct a staged anaerobic reaction space that is connected in sequence along the water flow direction. The incoming wastewater is subjected to hydrolysis and conversion treatment in the hydrolysis and acidification zone to convert macromolecular organic matter into volatile fatty acid intermediates. Wastewater treated in the hydrolysis and acidification zone is introduced into the acid-producing zone, where volatile fatty acid intermediates are subjected to acidification and conversion treatment to generate small molecule organic acid products. Wastewater treated in the acid-producing zone is introduced into the methanogenic zone, where methanogenic bacteria perform anaerobic metabolic reactions on small-molecule organic acid products to complete the stepwise anaerobic transformation of organic pollutants.

[0023] Specifically, in this embodiment, the staged anaerobic reaction unit is used to construct a multi-stage anaerobic reaction space that is sequentially connected along the water flow direction within the same reaction vessel, thereby enabling wastewater entering the system to sequentially complete the hydrolysis, acidification, and methanogenesis processes in different functional zones. By setting flow guide baffles and bottom connecting channels inside the reaction unit, the reaction unit is divided into a hydrolysis-acidification zone, an acidification zone, and a methanogenesis zone, allowing wastewater to flow step by step along a preset flow direction to form a staged anaerobic reaction structure.

[0024] In this embodiment, the flow guide baffle is arranged longitudinally along the reaction unit, forming a bottom connecting channel between the baffle and the bottom of the reaction unit, allowing hydraulic communication between adjacent functional areas. The height of the flow guide baffle is higher than the operating wastewater level by a certain proportion, thus requiring wastewater to change its flow path through the bottom connecting channel before entering the next reaction zone. This structural arrangement effectively extends the hydraulic residence path of wastewater within the reaction unit, while reducing the probability of short-circuiting.

[0025] A suspended sludge layer and a functional microbial carrier structure are set up in the hydrolysis acidification zone. Wastewater entering the hydrolysis acidification zone first comes into contact with the suspended sludge layer. Under the action of the hydrolytic bacteria, macromolecular organic matter is gradually decomposed into soluble organic matter, and further converted into volatile fatty acid intermediates. To improve the hydrolysis conversion efficiency, in this embodiment, a porous packing carrier can be arranged in the hydrolysis acidification zone, allowing the hydrolytic bacteria to attach and grow on the surface of the packing, thereby forming a stable microbial attachment interface. For example, in a certain application scenario, the domestic wastewater entering the system contains proteinaceous organic matter and polysaccharide organic matter. After being acted upon by the hydrolytic bacteria in the hydrolysis acidification zone, the above-mentioned macromolecular substances are gradually converted into volatile fatty acid intermediates such as acetic acid and propionic acid, and then flow into the downstream reaction zone with the water flow.

[0026] Further, after the hydrolysis and conversion treatment is completed, the wastewater enters the acid-producing zone through a bottom connecting channel. An anaerobic reaction environment suitable for the growth of acid-producing bacteria is established in the acid-producing zone, and by maintaining a suitable reaction temperature and sludge concentration, the volatile fatty acid intermediates undergo further acidification and conversion reactions. Under the metabolic action of the acid-producing bacteria, the volatile fatty acids generated in the hydrolysis and acidification stage are further decomposed and converted into small-molecule organic acid products, such as acetic acid and butyric acid. Simultaneously, a sedimentary sludge layer gradually forms at the bottom of the acid-producing zone, which is enriched with acid-producing bacteria, thus forming a stable acidification reaction zone.

[0027] For example, in a specific application example, the concentration of volatile fatty acids in the wastewater from the hydrolysis acidification zone is about 350 mg / L. After entering the acid-producing zone, by maintaining the temperature of the reaction zone at about 30°C and maintaining a suitable anaerobic environment, the intermediate products of volatile fatty acids are further converted into small molecule organic acid products, mainly acetic acid, under the action of acid-producing bacteria. This makes the available substrate form more stable and provides a reaction basis for the subsequent methanogenesis reaction.

[0028] Furthermore, the wastewater treated in the acid-producing zone continues to enter the methanogenic zone through the bottom connecting channel. Within the methanogenic zone, an anaerobic environment rich in methanogenic bacteria is formed. Through the metabolic activity of these bacteria, small-molecule organic acid products undergo further anaerobic metabolic reactions, generating methane gas and carbon dioxide, thus completing the stepwise anaerobic transformation process of organic pollutants.

[0029] In this embodiment, a granular sludge bed structure is formed at the bottom of the methanogenic zone, where methanogenic bacteria are enriched, thereby improving the organic load-bearing capacity of the reaction zone. To maintain the stable operation of the methanogenic zone, a gas release channel can be set at the top of the reaction zone to allow the methane gas generated during the reaction to be discharged in a timely manner, thus avoiding gas accumulation that could affect the reaction process.

[0030] For example, in a practical application, the acetic acid concentration in the wastewater after treatment in the acid-producing zone was approximately 220 mg / L. When the wastewater entered the methanogenic zone, under the action of methanogenic bacteria, small-molecule organic acids such as acetic acid were gradually converted into methane gas, and the concentration of organic pollutants in the reaction zone decreased significantly. As the reaction process continued, a stable anaerobic metabolic environment was formed in the methanogenic zone, thereby achieving further transformation of organic pollutants in the wastewater.

[0031] Through the aforementioned staged anaerobic reaction structure design, wastewater entering the system can sequentially complete hydrolysis, acidification, and methanogenesis processes in the hydrolysis-acidification zone, acid-producing zone, and methanogenesis zone. This constructs a step-by-step anaerobic transformation pathway, enabling large organic molecules to be gradually decomposed into small organic acids and further converted into gaseous products, achieving a continuous anaerobic transformation treatment process for organic pollutants. The staged reaction space and the hydraulic path constructed by the baffles and bottom connecting channels effectively extend the residence time of wastewater in the reaction unit and maintain a suitable microbial community environment in different functional zones, thereby improving the stability and treatment capacity of the anaerobic reaction process.

[0032] In some embodiments, the sludge co-degradation unit is specifically used for: The sludge is extracted and transported to the sludge activation reaction space by a sludge extraction structure set at the bottom of the staged anaerobic reaction unit to form a sludge circulation path. Shear disturbance treatment is performed on the deposited sludge in the sludge activation reaction space to break up the sludge floc structure and re-expose the microbial community and organic substrate in the deposited sludge. While performing floc destructive treatment, the deposited sludge is brought into contact with a microbial carrier loaded with hydrolytic and denitrifying bacteria to form a bio-attached structure and generate activated sludge. The generated activated sludge is recycled to the staged anaerobic reactor unit so that the activated sludge can participate in the anaerobic degradation process in the staged anaerobic reactor unit.

[0033] Specifically, in this embodiment, the sludge co-degradation unit is used to activate the deposited sludge formed during the operation of the staged anaerobic reactor and to construct a stable sludge circulation path within the system, allowing the microbial community in the deposited sludge to participate again in the degradation process of organic pollutants. By setting a sludge extraction structure at the bottom of the staged anaerobic reactor, the deposited sludge is extracted and transported to the sludge activation reaction space, thereby forming a sludge recycling process.

[0034] In some examples, the sludge extraction structure is located in the sedimentation zone at the bottom of the staged anaerobic reactor. This structure may include a sludge suction pipeline and a sludge transfer pump. The sludge inlet of the suction pipeline is located within the sedimentation zone at the bottom of the staged anaerobic reactor. The sludge transfer pump extracts the deposited sludge and transports it to the sludge activation reaction space. To ensure the stability of the sludge extraction process, the sludge transfer pump can operate according to a preset cycle, such as performing a sludge extraction operation at regular intervals, ensuring a continuous flow of bottom-sedied sludge into the sludge activation reaction space, thereby creating a stable sludge circulation path within the system.

[0035] Within the sludge activation reaction space, the transported sediment undergoes shear disturbance treatment. This shear disturbance is achieved through mechanical agitation devices or circulating mixing devices, creating a continuous shear flow field within the reaction space. This shear disturbance deconstructs the sludge floc structure, gradually breaking down and dispersing the flocs, thereby re-exposing the microbial community and organic substrate previously encased within the flocs.

[0036] In a specific application example, after the sludge deposited at the bottom of the staged anaerobic reactor enters the sludge activation reaction space, a local shear flow field is formed by a circulating stirring device, causing the sludge flocs to gradually break down into smaller particles. As the floc structure is broken down, the hydrolytic and denitrifying bacteria originally attached to the inside of the flocs are gradually released and re-participate in the reaction, thereby increasing the activity of the microbial community in the sludge.

[0037] During the floc decomposition treatment, the deposited sludge is brought into contact with a microbial carrier for reaction. This microbial carrier can be a porous biological packing material or a granular carrier material, with its surface pre-loaded with hydrolytic and denitrifying bacteria. Within the sludge activation reaction space, stirring and agitation ensure full contact between the deposited sludge and the microbial carrier, gradually forming a stable biological attachment structure on the carrier surface. As the reaction continues, the microbial community in the deposited sludge gradually adheres to the carrier surface, forming a composite microbial community with the existing hydrolytic and denitrifying bacteria, thus generating activated sludge.

[0038] For example, in a practical application scenario, a porous carrier with a particle size of 5mm to 10mm can be selected as the microbial carrier material, and hydrolytic and denitrifying bacteria can be pre-inoculated on the carrier surface. When the deposited sludge enters the sludge activation reaction space, the sludge particles and the carrier material are in continuous contact under the action of stirring, allowing microorganisms to gradually attach to the carrier surface and form a biofilm structure with high biological activity. As the reaction time increases, the activated sludge gradually forms a stable structure, enriching the carrier surface with a variety of functional bacteria.

[0039] Furthermore, after the activated sludge is generated, it is re-transported to the staged anaerobic reactor unit via a return conveying structure, allowing the activated sludge to participate in the staged anaerobic reaction process again. The return conveying structure may include a sludge return pipeline and a return pump. One end of the return pipeline is connected to the sludge activation reaction space, and the other end is connected to the inlet area or hydrolysis acidification zone of the staged anaerobic reactor unit. The return pump drives the activated sludge along the return pipeline, allowing it to re-enter the staged anaerobic reactor unit.

[0040] For example, in one application, activated sludge is returned to the hydrolysis and acidification zone, where the enriched hydrolytic bacteria can directly participate in the hydrolysis and transformation of macromolecular organic matter in the wastewater. Simultaneously, denitrifying bacteria in the activated sludge can also participate in the transformation of nitrogenous pollutants in a localized anaerobic environment. As the system continues to operate, a stable sludge circulation path gradually forms between the sludge activation reaction space and the staged anaerobic reaction units, ensuring that the deposited sludge is continuously activated and returned to the reaction system to participate in pollutant degradation.

[0041] Through the aforementioned structural design and operation mode, the sludge co-degradation unit can activate the sludge deposited in the staged anaerobic reactor, deconstructing the sludge floc structure and releasing the internal microbial community. Simultaneously, a stable bio-attachment structure is constructed through microbial carriers, thereby generating highly active activated sludge. The generated activated sludge re-enters the staged anaerobic reactor via a return path, allowing it to continuously participate in the anaerobic degradation process. This establishes a stable sludge recycling mechanism within the system, improving the utilization efficiency of the microbial community and enhancing the degradation and treatment capacity of organic pollutants.

[0042] In some embodiments, the micro-oxygen enhancement reaction unit is specifically used for: Wastewater treated by the staged anaerobic reaction unit is introduced into the micro-aerobic enhanced reaction unit, and gas is supplied to the reaction space through the set micro-aeration structure to form a micro-bubble mixed flow. The control commands output by the circulation control unit are used to adjust the air supply of the micro-gas aeration structure, so that the reaction space is maintained in a controlled dissolved oxygen state, thereby constructing a facultative reaction environment. In a facultative reaction environment, the microbial community in the returned sludge performs biological oxidation and reduction transformation processes on nitrogenous pollutants in wastewater. Wastewater that has undergone biological conversion treatment is transported to the deep purification unit.

[0043] Specifically, in this embodiment, the micro-aerobic enhanced reaction unit is used to perform further biological transformation treatment on the wastewater after it has been treated by the staged anaerobic reaction unit. By constructing a controlled dissolved oxygen environment within the reaction space, nitrogen pollutants in the wastewater can complete the biological oxidation and reduction transformation processes under facultative reaction conditions. The micro-aerobic enhanced reaction unit further promotes the transformation of nitrogen pollutants after anaerobic treatment and provides a stable influent water quality for subsequent deep purification units.

[0044] In some examples, wastewater treated by the staged anaerobic reactor first enters the reaction space of the microaerobic enhanced reactor through connecting pipes. A micro-aeration structure, which may include microporous aeration pipes or microporous aeration discs, is installed at the bottom of the reaction space. By continuously supplying gas to the micro-aeration structure, the gas is released in the form of microbubbles within the reaction space, forming a microbubble mixture in the water. Because microbubbles have a large specific surface area, they can form a long residence path in the water, allowing the gas to fully contact the wastewater and gradually dissolve it.

[0045] In some examples, the micro-aeration structure establishes a control connection with the circulation control unit. The circulation control unit collects dissolved oxygen parameters within the reaction space and outputs control commands according to a preset control strategy to adjust the air supply of the micro-aeration structure. When the circulation control unit detects that the dissolved oxygen concentration in the reaction space is lower than a preset range, it increases the air supply; when the dissolved oxygen concentration approaches the upper limit, it decreases the air supply, thereby maintaining the reaction space in a controlled dissolved oxygen state. For example, in a certain application scenario, the dissolved oxygen concentration in the reaction space can be maintained between 0.2 mg / L and 0.8 mg / L, keeping the reaction environment in a micro-oxygen state.

[0046] Through the aforementioned gas supply regulation mechanism, a facultative reaction environment can be constructed within the reaction space. In this environment, some microorganisms can utilize limited dissolved oxygen to carry out biological oxidation reactions, while others can carry out reduction reactions under localized hypoxic conditions, thus forming a synergistic transformation process within the same reaction space.

[0047] In some examples, returned sludge from the sludge co-degradation unit simultaneously enters the microaerobic enhanced reaction unit, creating a mixed system of wastewater and returned sludge within the reaction space. The returned sludge is enriched with various functional microbial communities, including nitrifying and denitrifying bacteria. Under microaerobic conditions, nitrifying bacteria utilize limited dissolved oxygen to perform biological oxidation of ammonia nitrogen in the wastewater, gradually converting it into nitrite or nitrate nitrogen. Simultaneously, in the locally anoxic areas of the reaction space, denitrifying bacteria utilize organic carbon sources in the wastewater as electron donors to perform a reduction conversion reaction on the generated nitrate nitrogen, further converting it into nitrogen gas and releasing it into the gas phase.

[0048] For example, in a practical application, the ammonia nitrogen concentration in wastewater treated by a staged anaerobic reactor was approximately 35 mg / L. When the wastewater entered the microaerobic enhanced reactor, under the action of microbubbles generated by the microaeration structure, nitrifying bacteria in the returned sludge gradually converted some of the ammonia nitrogen into nitrite and nitrate nitrogen. Simultaneously, in the localized anoxic zones within the reaction space, denitrifying bacteria utilized residual organic carbon sources in the wastewater to reduce nitrate nitrogen, converting some nitrogen into nitrogen gas which escaped from the water. As the reaction continued, nitrogenous pollutants in the wastewater were gradually transformed and treated.

[0049] Within the microaerobic enhanced reaction unit, as microbubble mixing flow continues to form, the water in the reaction space maintains a slow circulation state, creating a sufficient contact interface between wastewater and returned sludge, thereby improving the conversion efficiency of nitrogen pollutants by the microbial community. Simultaneously, the circulation control unit continuously adjusts the air supply to maintain a stable microaerobic environment in the reaction space, thus preserving the stable activity of the facultative microbial community.

[0050] In some examples, wastewater treated by the micro-aerobic enhanced reaction unit is transported to the advanced purification unit via an effluent pipeline. During this process, some nitrogenous pollutants in the wastewater are treated through biological transformation, further stabilizing the wastewater quality entering the advanced purification unit.

[0051] Through the aforementioned structure and operation of the micro-aerobic enhanced reaction unit, wastewater treated by the staged anaerobic reaction unit can fully contact the microbial community in the returned sludge in a micro-aerobic environment, thereby completing the biological oxidation and reduction transformation of nitrogen pollutants under facultative reaction conditions. The microbubble mixing flow formed by the micro-aeration structure and the regulation of air supply by the circulation control unit maintain a stable and controlled dissolved oxygen state in the reaction space, enabling nitrifying and denitrifying bacteria to synergistically participate in the nitrogen transformation reaction. This enhances the biological treatment process of nitrogen pollutants in wastewater and provides stable influent conditions for subsequent deep purification treatment.

[0052] In some embodiments, the deep purification unit is specifically used for: Wastewater treated by the micro-oxygen enhanced reaction unit is introduced into the deep purification unit, and the wastewater flows sequentially through the biological attached filter layer, the ion exchange adsorption layer and the carbon source release layer along a preset flow path. In the bio-attached filter media layer, a porous biological carrier is used to construct a bio-attachment interface, so that dissolved pollutants in wastewater can come into contact with and react with the attached microbial community to form a biotransformation process. Wastewater treated by the bio-attached filter layer is introduced into the ion exchange adsorption layer, where functionalized ion exchange materials are used to selectively exchange and adsorb ammonia nitrogen and dissolved ions in the wastewater. Wastewater treated by the ion exchange adsorption layer is introduced into the carbon source release layer. In the carbon source release layer, biodegradable carbon source is continuously released into the reaction water through slow-release solid carbon source material, so as to form an enhanced denitrification reaction environment in the deep purification unit.

[0053] Specifically, in this embodiment, the deep purification unit is used to further purify the wastewater after it has been treated by the micro-aerobic enhanced reaction unit. By constructing a multi-stage purification path within the same reaction structure, the wastewater passes sequentially through the biologically attached filter layer, the ion exchange adsorption layer, and the carbon source release layer along a preset flow path, thereby forming a synergistic treatment process of biological transformation, ion exchange adsorption, and enhanced denitrification reaction in the deep purification unit.

[0054] In some examples, wastewater treated by the micro-aerobic enhanced reaction unit first enters the inlet area of ​​the deep purification unit through connecting pipes, and then enters the bio-attachment filter layer under the guidance of the hydraulic flow guiding structure. The bio-attachment filter layer is filled with porous biological carrier material, which can be porous ceramic particles, biological filter media, or other porous fillers with a high specific surface area. Due to the numerous micropores on the surface of the porous carrier material, microbial communities can attach and grow on its surface, thereby forming a stable bio-attachment interface.

[0055] In some examples, when wastewater passes through the bio-attached filter media layer, the dissolved pollutants in the wastewater come into full contact with the microbial community attached to and growing on the porous carrier surface, and a biotransformation reaction occurs at this interface. For instance, in a specific application example, the wastewater treated by the microaerobic enhanced reaction unit still contains a certain concentration of dissolved organic matter and a small amount of ammonia nitrogen. When the wastewater passes through the bio-attached filter media layer, the microbial community attached to and growing on the porous carrier surface utilizes the organic substrate in the water for metabolic reactions, thereby further reducing the concentration of dissolved pollutants in the wastewater. At the same time, some residual ammonia nitrogen can also participate in the biotransformation reaction at this interface, further reducing the pollutant concentration.

[0056] In some examples, wastewater treated by the bio-attached filter layer then enters the ion exchange adsorption layer. In this embodiment, the ion exchange adsorption layer is filled with a functionalized ion exchange material, which can be a modified zeolite material or a resin-based ion exchange material, and its surface has active groups that can exchange with dissolved ions. When wastewater enters the ion exchange adsorption layer, ammonia nitrogen and some dissolved ions in the water undergo selective exchange reactions with the active groups on the surface of the ion exchange material, thereby being adsorbed and fixed on the material surface.

[0057] For example, in one application, the ammonia nitrogen concentration in the wastewater entering the ion exchange adsorption layer is approximately 12 mg / L. When the wastewater passes through the ion exchange adsorption layer filled with modified zeolite particles, ammonia nitrogen ions undergo an exchange reaction with the exchange sites on the surface of the zeolite material, causing the ammonia nitrogen to be gradually adsorbed and fixed within the material structure. Simultaneously, some dissolved cations in the water can also undergo ion exchange during this process, thereby reducing the concentration of soluble ions in the wastewater.

[0058] Furthermore, after the ion exchange adsorption treatment is completed, the wastewater continues to enter the carbon source release layer under the action of the hydraulic guiding structure. In this embodiment, the carbon source release layer is filled with a slow-release solid carbon source material, which can be a biodegradable organic carbon material, such as solid carbon source particles or composite carbon source carriers. When the wastewater flows through the carbon source release layer, the solid carbon source material gradually releases biodegradable carbon sources into the water, creating a stable organic carbon supply environment in the water.

[0059] Through the carbon source release process, an enhanced denitrification reaction environment can be formed inside the deep purification unit. Since some nitrogen pollutants have been converted into nitrate nitrogen in the micro-oxygen enhanced reaction unit, when the wastewater enters the carbon source release layer, the denitrifying bacteria in the water can use the biodegradable carbon source provided by the carbon source release layer as an electron donor to carry out a reduction conversion reaction on nitrate nitrogen, which is gradually converted into nitrogen gas and released into the gas phase space.

[0060] For example, in a specific application scenario, wastewater treated by the ion exchange adsorption layer still contains approximately 6 mg / L of nitrate nitrogen. When the wastewater enters the carbon source release layer, the slow-release solid carbon source material gradually releases biodegradable carbon source into the water, enabling denitrifying bacteria to continuously utilize this carbon source to perform a reduction and conversion reaction on nitrate nitrogen. As the reaction continues, nitrate nitrogen is gradually converted into nitrogen gas, thereby further reducing the concentration of nitrogen pollutants in the wastewater.

[0061] In some examples, during the operation of the deep purification unit, wastewater flows sequentially along the bio-attached filter media layer, the ion exchange adsorption layer, and the carbon source release layer, allowing the treatment mechanisms in different treatment layers to work synergistically. Specifically, the bio-attached filter media layer primarily performs biotransformation treatment, the ion exchange adsorption layer performs ion exchange adsorption treatment, and the carbon source release layer creates the environment for denitrification. Through this multi-stage treatment pathway, residual pollutants in the wastewater can be treated step by step.

[0062] Through the above structural design and operation mode, the deep purification unit can construct a multi-stage purification path within the same treatment structure, including biological attachment reaction, ion exchange adsorption, and enhanced denitrification reaction. This allows the wastewater treated by the micro-aerobic enhanced reaction unit to continue the pollutant transformation and removal process after entering the deep purification unit, thereby further reducing the concentration of pollutants such as dissolved organic matter, ammonia nitrogen, and nitrate nitrogen in the wastewater, improving the overall purification capacity of the system, and making the treated effluent quality more stable.

[0063] In some embodiments, the cyclic control unit is specifically used for: Dissolved oxygen, oxidation-reduction potential, ammonia nitrogen concentration, and sludge concentration parameters were collected from the tiered anaerobic reaction unit, microaerobic enhanced reaction unit, and deep purification unit, and a system operation status feature vector was constructed based on the operating parameters. The system's operating state feature vector is input into the adaptive operation and control model, where state determination and parameter optimization are performed to generate corresponding coordinated control instructions. The sludge transport flow rate in the sludge return path is adjusted based on the coordinated control command, and the oxygen supply intensity in the micro-aerobic enhanced reaction unit is adjusted simultaneously. The return ratio of the effluent from the deep purification unit is adjusted according to the coordinated control instructions to achieve coordinated adjustment of operating parameters between the sludge return path, the micro-aerobic enhancement reaction unit, and the deep purification unit.

[0064] Specifically, in this embodiment, the circulation control unit is used to perform unified monitoring and coordinated control of the operating status among the staged anaerobic reaction unit, the micro-aerobic enhanced reaction unit, and the deep purification unit, so that each treatment unit forms a linkage control relationship during operation. By collecting and analyzing key operating parameters and generating coordinated control instructions in combination with an adaptive operation control model, dynamic and coordinated adjustment of the sludge return path, the oxygen supply intensity of the micro-aerobic enhanced reaction unit, and the return ratio of the deep purification unit can be achieved.

[0065] In some examples, the circulation control unit first acquires system operating parameters through sensors deployed in each treatment unit. Specifically, the staged anaerobic reaction unit is equipped with dissolved oxygen and oxidation-reduction potential sensors to acquire dissolved oxygen and oxidation-reduction potential parameters in the reaction space; the microaerobic enhanced reaction unit is equipped with dissolved oxygen sensors, online ammonia nitrogen detectors, and sludge concentration detectors to acquire dissolved oxygen, ammonia nitrogen, and sludge concentration parameters; and the deep purification unit is equipped with oxidation-reduction potential sensors and ammonia nitrogen detectors to acquire oxidation-reduction potential and ammonia nitrogen concentration parameters in the reaction water.

[0066] In some examples, the cyclic control unit periodically reads the aforementioned operating parameters through a data acquisition interface and performs time alignment and data normalization on the acquired data, ensuring that parameter data from different processing units have a unified time stamp. After data normalization, dissolved oxygen, oxidation-reduction potential, ammonia nitrogen concentration, and sludge concentration parameters are combined according to a preset data structure to construct a system operating state feature vector. This system operating state feature vector is used to characterize the overall operating state of the current treatment system.

[0067] In some examples, the constructed system operating state feature vector is input into an adaptive operation control model. This adaptive operation control model can be deployed on a control server or industrial control computing unit and trained based on historical operating data, enabling the model to predict and analyze system operating parameters according to the current operating state. Internally, the model first performs a state determination operation to determine the current operating state of the system. For example, when dissolved oxygen is at a low level and ammonia nitrogen concentration is rising, the model can determine that the system is in a state of increasing ammonia nitrogen load; when the redox potential parameter shows a significant decrease and sludge concentration increases, the model can determine that the system is in a state of changing sludge load.

[0068] Furthermore, after determining the operational status, the adaptive operation and control model performs parameter optimization calculations. By analyzing the current operational status, the model calculates suitable combinations of operational parameters based on preset optimization objectives and outputs corresponding coordinated control commands. These coordinated control commands may include sludge transport flow rate adjustment parameters, oxygen supply intensity adjustment parameters, and effluent recirculation ratio parameters.

[0069] In some examples, the circulation control unit first adjusts the sludge transport flow rate in the sludge return path according to the coordinated control command. For example, when the model determines that the ammonia nitrogen concentration in the system is rising and the microbial activity is insufficient, the circulation control unit can increase the operating frequency of the sludge return pump, thereby increasing the transport flow rate of the returned sludge into the microaerobic enhanced reaction unit, allowing more microbial communities to participate in the reaction process.

[0070] Simultaneously, the circulation control unit synchronously adjusts the oxygen supply intensity in the micro-aerobic enhanced reaction unit according to the coordinated control command. Specifically, it adjusts the oxygen supply in the reaction space by controlling the opening of the air supply valve of the micro-aeration structure or the operating frequency of the aeration equipment. For example, in a certain operating example, when the dissolved oxygen concentration in the micro-aerobic enhanced reaction unit is detected to drop to 0.15 mg / L, the adaptive operation control model outputs a control command to increase the oxygen supply intensity. The circulation control unit then increases the air supply of the aeration equipment accordingly, so that the dissolved oxygen concentration in the reaction space gradually recovers to the preset range.

[0071] Furthermore, after adjusting the sludge return flow rate and oxygen supply intensity, the circulation control unit further adjusts the return ratio of the effluent from the deep purification unit according to the coordinated control command. In this embodiment, the effluent from the deep purification unit forms a return path with the system's front-end treatment unit through the return pipeline. When the system detects a high nitrate nitrogen concentration in the deep purification unit, the adaptive operation control model can generate a control command to increase the effluent return ratio. The circulation control unit adjusts the opening of the return valve accordingly, allowing some of the effluent to re-enter the front-end reaction unit, thereby increasing the water circulation volume during the denitrification process.

[0072] For example, in a specific application scenario, when the ammonia nitrogen concentration in the micro-aerobic enhancement reaction unit rises from 8 mg / L to 14 mg / L during system operation, the circulation control unit, based on the collaborative control instructions output by the adaptive operation control model, increases the sludge return pump frequency to 1.2 times the original operating frequency, simultaneously increases the air supply of the micro-aeration structure by approximately 15%, and increases the effluent return ratio of the deep purification unit from 10% to 20%. With the implementation of these adjustment measures, the activity of the microbial community in the system gradually recovers, and the ammonia nitrogen concentration gradually decreases and returns to a stable range.

[0073] By using the above-mentioned cyclic control unit operation mode, key operating parameters of each treatment unit can be continuously collected during system operation. Based on the adaptive operation control model, the system operation status can be judged and parameters optimized, so that a linkage adjustment relationship is formed between the sludge return path, the oxygen supply intensity of the micro-aerobic enhanced reaction unit and the return ratio of the deep purification unit. This enables each treatment unit to maintain a coordinated operation state under different operating conditions, improves the overall operation stability of the system, and enhances the adaptability of the sewage treatment system to load fluctuations.

[0074] In some embodiments, the system operating state feature vector is input into the adaptive operation control model, and state determination and parameter optimization operations are performed in the adaptive operation control model to generate corresponding coordinated control instructions, including: The feature vector of the system operation status is normalized, and the status evaluation results corresponding to the hierarchical anaerobic reaction unit, micro-aerobic enhanced reaction unit and deep purification unit are generated based on the preset operation status evaluation rules. The state evaluation results are input into a multi-objective parameter optimization model. In the multi-objective parameter optimization model, the sludge return flow rate, oxygen supply intensity and deep purification unit return ratio are used as parameters to be adjusted to construct a parameter optimization space. Perform iterative optimization operations within the parameter optimization space to determine the target combination of operating parameters that matches the current system operating state; Based on the target combination of operating parameters, a coordinated control command is generated and output to the cyclic control unit to perform system operating parameter adjustment.

[0075] Specifically, in this embodiment, the adaptive operation control model is used to perform comprehensive analysis and optimization calculations on key operating parameters based on the real-time operating status of the wastewater treatment system, thereby generating coordinated control commands to adjust the sludge return flow rate, oxygen supply intensity, and return ratio of the deep purification unit in a coordinated manner. Through the setting of this model, the system can dynamically match suitable combinations of operating parameters under different operating conditions, thereby maintaining the coordinated operation of each treatment unit.

[0076] In some examples, the circulating control unit first constructs a system operating state feature vector based on dissolved oxygen, redox potential, ammonia nitrogen concentration, and sludge concentration parameters collected from each treatment unit. To ensure that different types of operating parameters have uniform dimensions during model calculations, feature normalization processing needs to be performed on the feature vector before inputting it into the adaptive operation control model.

[0077] In some examples, the adaptive operation control model first reads the parameter values ​​from the system's operating state feature vector and then normalizes these parameters according to a preset parameter range. For instance, the maximum and minimum values ​​of each parameter can be determined based on its historical operating range, and the currently collected parameter values ​​can be mapped to a unified numerical range using a normalization formula, thereby generating a normalized operating state feature vector. Through this process, dissolved oxygen, oxidation-reduction potential, ammonia nitrogen concentration, and sludge concentration parameters can have a consistent numerical scale during model calculations.

[0078] Furthermore, after feature normalization, the adaptive operation control model evaluates the system's operating status according to preset operating status evaluation rules. In this embodiment, the preset operating status evaluation rules are used to determine whether the current processing unit is in a stable operating state based on the operating parameters of different processing units. Specifically, corresponding status evaluation results can be generated for the graded anaerobic reaction unit, the microaerobic enhanced reaction unit, and the deep purification unit.

[0079] For example, in a specific operational example, when the redox potential parameter in the staged anaerobic reactor remains within a preset range and the sludge concentration is stable, the staged anaerobic reactor can be determined to be in a stable operating state. When the dissolved oxygen parameter in the microaerobic enhancement reactor deviates from the preset microaerobic range and the ammonia nitrogen concentration shows an upward trend, the microaerobic enhancement reactor can be determined to be in a load change state. When the redox potential parameter in the deep purification unit is lower than a preset threshold, the degree of denitrification in the deep purification unit can be determined to be insufficient. Through the above operational status evaluation process, status evaluation results corresponding to each treatment unit can be generated.

[0080] After obtaining the state evaluation results, the adaptive operation and control model inputs these results into the multi-objective parameter optimization model. In this embodiment, the multi-objective parameter optimization model is used to find suitable parameter combinations among multiple operating parameters to stabilize the system's operating state. In the model, sludge return flow rate, oxygen supply intensity, and the return ratio of the deep purification unit are used as parameters to be adjusted, thereby constructing a parameter optimization space.

[0081] Within this parameter optimization space, each parameter combination corresponds to a set of possible system operating parameters. For example, in a certain application scenario, the sludge return flow rate can vary within a set range, the oxygen supply intensity can be adjusted by regulating the operating frequency of the aeration equipment, and the return ratio of the deep purification unit can be adjusted by controlling the opening of the return valve. The multi-objective parameter optimization model combines different parameter values ​​within the aforementioned parameter range to form multiple candidate operating parameter combinations.

[0082] In some examples, the multi-objective parameter optimization model performs iterative optimization operations within the parameter optimization space. In each iteration, the model evaluates each candidate parameter combination based on the current system operating state and gradually selects a more suitable parameter combination based on the evaluation results. For example, when the system detects a high ammonia nitrogen concentration in the microaerobic enhancement reaction unit, the model will prioritize parameter combinations that can increase oxygen supply intensity and moderately increase sludge return flow rate during the iteration process; when the nitrate nitrogen concentration in the deep purification unit is high, it will prioritize parameter combinations that increase the effluent return ratio.

[0083] Furthermore, as the iteration process continues, the multi-objective parameter optimization model gradually narrows the parameter search range and finally determines the target operating parameter combination that matches the current system operating state. This target operating parameter combination includes the target value of sludge return flow rate, the target value of oxygen supply intensity of the micro-aerobic enhanced reaction unit, and the target value of return ratio of the deep purification unit.

[0084] Furthermore, after obtaining the target combination of operating parameters, the adaptive operation and control model generates coordinated control instructions based on the target combination of operating parameters. The coordinated control instructions include control parameters for adjusting the operating frequency of the sludge return pump, control parameters for adjusting the air supply of the micro-aeration structure, and control parameters for adjusting the opening of the return valve of the deep purification unit.

[0085] Furthermore, the generated coordinated control instructions are then sent to the circulation control unit. The circulation control unit performs actual adjustments to the system operating parameters based on the received coordinated control instructions. For example, the sludge return flow rate is changed by adjusting the operating frequency of the sludge return pump, the oxygen supply intensity in the micro-aerobic enhanced reaction unit is changed by adjusting the opening of the air supply valve of the aeration equipment, and the effluent return ratio of the deep purification unit is changed by adjusting the opening of the return valve.

[0086] For example, in a specific application scenario, when the system detects that the ammonia nitrogen concentration in the micro-aerobic enhancement reaction unit has risen to 15 mg / L and the nitrate nitrogen concentration in the deep purification unit has risen to 8 mg / L, the adaptive operation control model performs parameter optimization calculations based on the operation status evaluation results and determines the target combination of operating parameters as follows: sludge return flow rate is increased to 1.3 times the original operating value, oxygen supply intensity is increased by approximately 20%, and the return ratio of the deep purification unit is increased from 10% to 25%. Upon receiving the coordinated control command, the circulation control unit executes corresponding parameter adjustments to gradually restore the system to a stable operating state.

[0087] By employing the aforementioned adaptive operation and control model, key operating parameters can be dynamically optimized based on the real-time operating status of the wastewater treatment system, generating corresponding coordinated control commands. This establishes a linked adjustment relationship between sludge return flow rate, oxygen supply intensity, and the return ratio of the deep purification unit. Through this mechanism, the system can automatically adjust the combination of operating parameters according to different operating conditions, thereby improving the operational stability of the wastewater treatment system under load variations and enhancing the coordinated treatment capabilities among the various treatment units.

[0088] In some embodiments, a gas-liquid disturbance component is provided in the sludge activation reaction space. The gas-liquid disturbance component is used to release microbubble airflow into the sludge activation reaction space and form a gas-liquid mixed disturbance flow, so that the deposited sludge entering the sludge activation reaction space forms a dispersed sludge structure under the action of gas-liquid shearing and promotes the contact reaction between the deposited sludge and the microbial carrier.

[0089] Specifically, in this embodiment, the sludge activation reaction space is used to perform activation treatment on the deposited sludge generated during system operation. By setting up a gas-liquid disturbance component in the reaction space, the deposited sludge forms a dispersed sludge structure under the action of gas-liquid shearing, thereby promoting the contact reaction between the deposited sludge and the microbial carrier and restoring the activity of the microbial community in the deposited sludge.

[0090] In some examples, the sludge activation reaction space is connected to the front-end treatment unit via sludge transport pipelines. Sediment from the staged anaerobic reaction unit or the system settling zone is transported to the sludge activation reaction space via a sludge transport device. After the sludge enters the reaction space, the sediment first forms a sludge layer of a certain thickness at the bottom of the reaction space. Because the sediment structure is relatively dense and its internal mass transfer capacity is weak, external disturbance is required to loosen the sludge structure.

[0091] To achieve the aforementioned disturbance process, a gas-liquid disturbance component is installed inside the sludge activation reaction space. This component may include microporous aeration pipes, gas distribution pipes, and air supply pipes. The gas distribution pipes are located at the bottom of the sludge activation reaction space and are connected to an air source device via the air supply pipes. When the air source device supplies air to the gas-liquid disturbance component, the gas is released into the water within the reaction space through the microporous structure, thereby forming a large volume of microbubble airflow.

[0092] In some examples, as microbubbles rise in the water, they create gas-liquid mixing disturbances in the surrounding water. Because the microbubbles continuously change their flow paths as they rise, a complex flow structure gradually forms within the reaction space, subjecting the deposited sludge to continuous gas-liquid shearing. Under the influence of these shearing forces, the originally tightly packed sludge is gradually broken up, loosening the bonds between sludge particles and forming a dispersed sludge structure.

[0093] Furthermore, as the gas-liquid disturbance process continues, the fine particles in the deposited sludge gradually become suspended in the water, creating a larger contact interface between the sludge and the microbial carrier in the reaction space. In this embodiment, a microbial carrier structure is also provided in the sludge activation reaction space. This microbial carrier can be a porous packing material or a suspended biological carrier, with a large number of active microbial communities attached to its surface.

[0094] In some examples, when the dispersed sludge structure comes into contact with the microbial carrier, the organic matter and nitrogenous substances in the sludge particles can be utilized by the microbial community attached to the surface of the microbial carrier, thereby undergoing a biotransformation reaction. Simultaneously, under the continuous action of the gas-liquid turbulent flow, the sludge particles and the microbial carrier maintain continuous contact, allowing the microbial community to gradually form new attachment structures on the surface of the sludge particles, thus promoting the re-accumulation of microorganisms in the sludge.

[0095] For example, in a specific application, after long-term system operation, some of the deposited sludge gradually accumulates in the settling area, forming a relatively thick sludge layer. The circulation control unit transports some of the deposited sludge to the sludge activation reaction space by controlling the sludge conveying device. When the gas-liquid disturbance component starts working, a large number of microbubbles are released from the bottom of the reaction space, forming an upward airflow in the water, which gradually disperses the deposited sludge under the shearing action of gas and liquid. As the disturbance process continues, the sludge particles gradually become suspended and come into full contact with the microbial carrier, allowing the microbial community in the sludge to regain its growth space.

[0096] During this process, the microbubbles released by the gas-liquid disturbance component not only provide disturbance but also introduce dissolved oxygen into the water in the reaction space to a certain extent, enabling some aerobic or facultative microorganisms to restore their metabolic activity and thus promote the degradation of organic matter in the sludge. Once the sludge particles gradually form a stable dispersed structure, the activated sludge can be transported back to the system treatment unit through the sludge discharge pipeline to participate in the reaction process.

[0097] In some examples, the gas supply to the gas-liquid disturbance component can be adjusted according to the sludge concentration and the volume of the reaction space. For example, when the sludge concentration in the sludge activation reaction space is high, the gas supply can be appropriately increased to enhance the gas-liquid disturbance intensity; when the sludge concentration gradually decreases, the gas supply can be reduced to maintain a stable disturbance state. By adjusting the gas-liquid disturbance intensity, the deposited sludge can gradually complete the activation process.

[0098] Through the above structural setup and operation mode, microbubble airflow is released through the gas-liquid disturbance component in the sludge activation reaction space, causing the deposited sludge to form a dispersed sludge structure under the action of gas-liquid shearing. This promotes full contact between the deposited sludge and the microbial carrier, thereby gradually restoring the activity of the microbial community in the deposited sludge, improving the sludge reuse capacity, and continuously providing active sludge resources for the system treatment unit, thus improving the operational stability and treatment efficiency of the entire wastewater treatment system.

[0099] In some embodiments, the microbial carrier is a porous biological carrier structure, and the surface of the porous biological carrier is loaded with a complex functional bacterial community, including hydrolytic bacteria, acid-producing bacteria and denitrifying bacteria, so as to form a stable biofilm structure in the sludge activation reaction space and participate in the anaerobic degradation reaction when the activated sludge is returned to the staged anaerobic reaction unit.

[0100] Specifically, in this embodiment, a microbial carrier structure is set within the sludge activation reaction space to construct a stable bio-attachment interface. This allows the deposited sludge entering the sludge activation reaction space to contact and react with the attached microbial community, thereby promoting organic matter degradation and nitrogen conversion reactions during the sludge activation process. In this embodiment, the microbial carrier adopts a porous biological carrier structure, with its surface loaded with a composite functional bacterial community. By constructing a stable biofilm structure, the microbial community can maintain stable activity within the reaction space for a long period of time.

[0101] In some examples, porous biocarrier structures can be composed of porous ceramic aggregate carriers, biological filler carriers, or composite polymer porous materials. These carrier materials possess numerous interconnected micropores and a rough surface structure, resulting in a large specific surface area, thus providing ample space for microbial attachment and growth. The porous structure can also create micro-flow channels within the carrier, allowing the reaction water to flow slowly within the carrier, thereby increasing the probability of contact between pollutants and the microbial community in the water.

[0102] In some examples, a composite functional microbial community can be pre-cultured on the surface of the porous biological carrier before it is introduced into the sludge activation reaction space. This composite functional microbial community includes hydrolytic bacteria, acid-producing bacteria, and denitrifying bacteria. Through the combination and configuration of these microbial communities, the sludge activation reaction space can simultaneously possess multiple biological reaction capabilities.

[0103] Among them, the hydrolytic bacteria are mainly used to perform hydrolysis reactions on complex organic matter in sludge, decomposing large organic molecules in sludge into soluble small organic molecules; the acid-producing bacteria use the small organic molecules generated by the hydrolysis reaction to perform fermentation reactions, thereby generating intermediate products such as volatile fatty acids; and the denitrifying bacteria use organic carbon sources in the water as electron donors under anaerobic conditions to perform reduction reactions on nitrate nitrogen, thereby gradually converting nitrogen pollutants into nitrogen gas and releasing it into the gas phase space.

[0104] Furthermore, during the operation of the sludge activation reaction space, porous biological carriers are distributed within the reaction space and held in the reaction water by support structures or suspension. When the deposited sludge enters the sludge activation reaction space through the sludge conveying device, it is gradually dispersed into a dispersed sludge structure under the action of the gas-liquid mixing turbulence flow formed by the gas-liquid disturbance component. The dispersed sludge particles continuously come into contact with the porous biological carriers under the influence of the turbulence flow.

[0105] In some examples, when sludge particles come into contact with the complex functional microbial community on the surface of a porous biocarrier, the organic matter in the sludge is gradually utilized by the attached microbial community. For instance, in one specific application, the deposited sludge entering the sludge activation reaction space contains a high concentration of complex organic matter. When the sludge particles come into contact with the hydrolytic microbial community on the surface of the porous biocarrier, the complex organic matter is first hydrolyzed into smaller organic molecules. Subsequently, the acidogenic microbial community further performs fermentation reactions on these smaller organic molecules, thereby generating intermediate metabolites such as volatile fatty acids.

[0106] As the reaction continues, the denitrifying bacteria in the sludge activation reaction space can utilize the aforementioned intermediate metabolites as a carbon source to reduce nitrate nitrogen in an anaerobic environment. Through this continuous biological reaction process, the organic matter in the sludge is gradually degraded, while nitrogenous pollutants are gradually transformed.

[0107] In some examples, the microbial communities on the surface of the porous biocarrier gradually form a stable biofilm structure during long-term operation. This biofilm structure consists of multiple layers of microbial communities, with the outer layer mainly composed of hydrolytic and acid-producing bacteria, while the inner layer is enriched with denitrifying bacteria. The stable biofilm structure formed on the porous carrier surface allows the microbial community to maintain high stability within the reaction space, thus enabling it to continuously participate in the biological reaction process during sludge activation.

[0108] In some examples, after the sludge in the sludge activation reaction space has gradually completed the activation process, the activated sludge can be returned to the staged anaerobic reactor unit via a return pipeline. Upon entering the staged anaerobic reactor unit, the microbial community in the activated sludge can continue to participate in the anaerobic degradation reaction. For example, in one operational example, when the activated sludge enters the staged anaerobic reactor unit, the enriched hydrolytic bacteria can perform hydrolytic degradation reactions on the organic pollutants entering the system, while the acid-producing bacteria further promote the fermentation and decomposition of organic matter, thereby improving the organic matter degradation efficiency in the staged anaerobic reactor unit.

[0109] At the same time, the denitrifying bacteria retained in the activated sludge can still participate in the nitrogen conversion process under suitable conditions, enabling nitrogen pollutants in the staged anaerobic reaction unit to undergo gradual reduction and transformation, thereby improving the overall pollutant treatment capacity of the system.

[0110] Through the above structural configuration and operation mode, a stable biological attachment interface is constructed in the sludge activation reaction space through a porous biological carrier. A composite functional microbial community composed of hydrolytic bacteria, acid-producing bacteria and denitrifying bacteria is loaded on the surface of the carrier, so that the deposited sludge can fully contact the functional microbial community during the activation process, thereby promoting the degradation of organic matter and nitrogen conversion reaction in the sludge. After the activated sludge is returned to the staged anaerobic reaction unit, it continues to participate in the anaerobic degradation reaction, thereby improving the stability of the microbial community in the system and enhancing the overall treatment capacity of the sewage treatment system.

[0111] The above embodiments have described in detail the specific components and functions of the sludge degradation synergistic septic tank wastewater treatment deep purification system of this application. The implementation process of the sludge degradation synergistic septic tank wastewater treatment deep purification method of this application will be described in detail below with reference to specific embodiments. Figure 3 This is a schematic flowchart of the sludge degradation synergistic deep purification method for septic tank wastewater treatment provided in the embodiments of this application, as shown below. Figure 3 As shown, the method may specifically include the following steps: S301 receives pretreated wastewater and introduces it into a staged anaerobic reaction unit, so that the wastewater passes through the hydrolysis acidification zone, acid production zone and methanogenesis zone set along the water flow direction in sequence, so as to perform step-by-step anaerobic transformation treatment on the organic pollutants in the wastewater. S302, the sedimented sludge is extracted from the bottom of the staged anaerobic reaction unit and transported to the sludge activation reaction space. In the sludge activation reaction space, the sedimented sludge is subjected to floc destructive treatment and the sedimented sludge is brought into contact with the microbial carrier loaded with functional bacteria to generate activated sludge. The activated sludge is then returned to the staged anaerobic reaction unit. S303 introduces wastewater treated by the staged anaerobic reaction unit into the micro-aerobic enhanced reaction unit to create a facultative reaction environment under controlled dissolved oxygen conditions, so that the microbial community in the returned sludge can carry out biotransformation reactions on nitrogen pollutants in the wastewater. S304 introduces the wastewater treated by the micro-oxygen enhanced reaction unit into the deep purification unit, so that the wastewater passes through the biological attached filter layer, the ion exchange adsorption layer and the carbon source release layer in sequence to perform multi-stage filtration and adsorption treatment on the wastewater. S305 collects operating parameters from the graded anaerobic reaction unit, the micro-aerobic enhanced reaction unit, and the deep purification unit, and adjusts the sludge transport flow rate in the sludge return path, the oxygen supply intensity in the micro-aerobic enhanced reaction unit, and the return ratio of the deep purification unit based on the operating parameters.

[0112] Specifically, in step S301, the pretreated wastewater is first received and then introduced into a staged anaerobic reaction unit, so that the wastewater passes through the hydrolysis acidification zone, acid production zone and methanogenesis zone arranged along the water flow direction in sequence, so as to perform step-by-step anaerobic transformation treatment on the organic pollutants in the wastewater.

[0113] In practice, pretreated wastewater can originate from the sedimentation zone of a septic tank or a bar screen filter. This wastewater typically contains high concentrations of suspended and dissolved organic matter. Upon entering the staged anaerobic reactor, the wastewater first flows through the hydrolysis and acidification zone. In this zone, hydrolytic bacteria break down large organic molecules in the wastewater into smaller ones, such as proteins and polysaccharides, which are then broken down into soluble organic compounds like amino acids and monosaccharides. Subsequently, the wastewater enters the acid-producing zone, where acid-producing bacteria further ferment the smaller organic molecules to produce intermediate products such as volatile fatty acids. Finally, the wastewater enters the methanogenic zone, where methanogenic bacteria convert some of the intermediate products into methane and carbon dioxide, thus gradually degrading the organic pollutants in the wastewater.

[0114] In step S302, the deposited sludge is extracted from the bottom of the graded anaerobic reaction unit and transported to the sludge activation reaction space. In the sludge activation reaction space, the deposited sludge is subjected to floc destructive treatment, and the deposited sludge is brought into contact with the microbial carrier loaded with functional bacteria to generate activated sludge. The activated sludge is then returned to the graded anaerobic reaction unit.

[0115] In practice, during long-term operation, some sludge gradually deposits at the bottom of the anaerobic reaction unit, forming a dense sludge layer. After the deposited sludge is transported to the sludge activation reaction space via a sludge conveying device, it undergoes continuous gas-liquid shearing under the action of microbubble airflow released by the gas-liquid disturbance component. This causes the originally tightly structured sludge flocs to gradually break down and form a dispersed sludge structure. Simultaneously, a porous biological carrier structure is installed within the sludge activation reaction space. The surface of this carrier is loaded with a complex functional microbial community composed of hydrolytic bacteria, acid-producing bacteria, and denitrifying bacteria. When the dispersed sludge particles come into contact with the microbial community on the carrier surface, the organic matter in the sludge can be further degraded by the microbial community, thus forming highly active activated sludge. Subsequently, the activated sludge is transported back to the staged anaerobic reaction unit through a return pipeline, allowing the activated sludge to participate in the anaerobic degradation process again.

[0116] In step S303, the wastewater treated by the staged anaerobic reaction unit is introduced into the micro-aerobic enhanced reaction unit to construct a facultative reaction environment under controlled dissolved oxygen conditions, so that the microbial community in the returned sludge can perform biotransformation reactions on nitrogen pollutants in the wastewater.

[0117] In practice, the micro-oxygen-enhanced reaction unit supplies gas to the reaction space through a micro-aeration structure, and adjusts the gas supply under the control of the circulation regulation unit to maintain the dissolved oxygen concentration in the reaction space within the micro-oxygen range. For example, the dissolved oxygen concentration can be maintained between approximately 0.2 mg / L and 0.8 mg / L. Under these conditions, some nitrifying bacteria utilize the limited dissolved oxygen to perform biological oxidation of ammonia nitrogen in the wastewater, gradually converting ammonia nitrogen into nitrite nitrogen or nitrate nitrogen. Simultaneously, in locally anoxic areas, denitrifying bacteria utilize organic carbon sources in the water to perform a reduction conversion reaction on nitrate nitrogen, converting it into nitrogen gas and releasing it into the gas phase space, thereby reducing the concentration of nitrogen pollutants in the wastewater.

[0118] In step S304, the wastewater treated by the micro-oxygen enhanced reaction unit is introduced into the deep purification unit, so that the wastewater passes through the biologically attached filter media layer, the ion exchange adsorption layer and the carbon source release layer in sequence to perform multi-stage filtration and adsorption treatment on the wastewater.

[0119] In practice, wastewater first enters a bio-attached filter layer, which is filled with porous biological filter media on which microbial communities can attach and grow. As wastewater flows through this area, dissolved pollutants in the water come into contact with the microbial community and undergo biotransformation. Next, the wastewater enters an ion exchange adsorption layer, which is filled with functionalized ion exchange materials, such as modified zeolite or resin materials. These materials have ion exchange sites on their surfaces, enabling selective exchange adsorption of ammonia nitrogen and some dissolved ions in the wastewater. Finally, the wastewater enters a carbon source release layer, which is filled with slow-release solid carbon source materials. As wastewater flows through this area, the solid carbon source materials gradually release biodegradable carbon sources into the water, providing electron donors for denitrifying bacteria and further reducing and transforming residual nitrate nitrogen in the water.

[0120] In step S305, the operating parameters of the graded anaerobic reaction unit, the micro-aerobic enhanced reaction unit and the deep purification unit are collected, and the sludge transport flow rate in the sludge return path, the oxygen supply intensity in the micro-aerobic enhanced reaction unit and the return ratio of the deep purification unit are adjusted based on the operating parameters.

[0121] In practical implementation, the circulation control unit collects dissolved oxygen, oxidation-reduction potential, ammonia nitrogen concentration, and sludge concentration parameters through sensors, and constructs these parameters into a system operating status feature vector. Subsequently, the adaptive operation control model performs parameter optimization calculations based on the current operating status and generates corresponding coordinated control commands. For example, when an increase in ammonia nitrogen concentration is detected in the micro-aerobic enhancement reaction unit, the biological conversion capacity can be enhanced by increasing the sludge return flow rate and oxygen supply intensity; when the nitrate nitrogen concentration is high in the deep purification unit, the effluent return ratio can be increased to enhance the denitrification process.

[0122] Through the coordinated execution of the above methods and steps, this application achieves the stepwise anaerobic degradation of organic pollutants through a graded anaerobic reaction unit, the activation and reuse of deposited sludge through a sludge activation reaction space, the biotransformation of nitrogen pollutants through a micro-aerobic enhanced reaction unit, and multi-stage adsorption and biological reaction treatment through a deep purification unit. At the same time, the system operating parameters are dynamically adjusted by a circulation control mechanism, thereby forming a stable multi-stage pollutant treatment path in the septic tank sewage treatment process, improving the overall sewage purification capacity of the system and enhancing the system's operational stability.

[0123] It should be understood that the sequence number of each step in the above method embodiments does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0124] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although the technical solutions of this application have 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 this application, and should all be included within the protection scope of this application.

Claims

1. A septic tank wastewater treatment and deep purification system with synergistic sludge degradation, characterized in that, include: The staged anaerobic reaction unit is used to receive pretreated wastewater and construct a step-by-step anaerobic reaction path in the hydrolysis acidification zone, acid production zone and methanogenesis zone set along the water flow direction to perform staged conversion treatment of organic pollutants in wastewater. The sludge co-degradation unit is used to extract the deposited sludge from the bottom of the graded anaerobic reaction unit and transport it to the sludge activation reaction space. In the sludge activation reaction space, the deposited sludge is subjected to floc destructive treatment, and the deposited sludge is brought into contact with the microbial carrier loaded with functional bacteria to generate activated sludge. The activated sludge is then returned to the graded anaerobic reaction unit to participate in the anaerobic degradation process. The micro-aerobic enhanced reaction unit is used to receive wastewater after it has been treated by the staged anaerobic reaction unit and to form a facultative reaction environment under controlled dissolved oxygen conditions, so that the microbial community in the returned sludge can carry out biotransformation reactions on nitrogen pollutants. The deep purification unit is used to receive wastewater after it has been treated by the micro-oxygen enhanced reaction unit, and to perform multi-stage filtration and adsorption treatment on the wastewater through a biological attachment filter media layer, an ion exchange adsorption layer and a carbon source release layer arranged in sequence. The circulation control unit is used to collect the operating parameters of the staged anaerobic reaction unit, the micro-aerobic enhanced reaction unit and the deep purification unit, and adjust the sludge transport flow rate in the sludge return path, the oxygen supply intensity in the micro-aerobic enhanced reaction unit and the return ratio of the deep purification unit based on the operating parameters, so as to perform coordinated adjustment of the system operating parameters.

2. The system according to claim 1, characterized in that, The hierarchical anaerobic reaction unit is specifically used for: By setting up flow guide baffles and bottom connecting channels, the staged anaerobic reaction unit is divided into a hydrolysis acidification zone, an acid production zone, and a methanogenic zone that are connected in sequence, so as to construct a staged anaerobic reaction space that is connected in sequence along the water flow direction. The incoming wastewater is subjected to hydrolysis and conversion treatment in the hydrolysis and acidification zone to convert macromolecular organic matter into volatile fatty acid intermediates. Wastewater treated in the hydrolysis and acidification zone is introduced into the acid-producing zone, where the volatile fatty acid intermediates are subjected to acidification and conversion treatment to generate small molecule organic acid products. Wastewater treated in the acid-producing zone is introduced into the methanogenic zone, where methanogenic bacteria perform anaerobic metabolic reactions on the small-molecule organic acid products to complete the stepwise anaerobic transformation of organic pollutants.

3. The system according to claim 1, characterized in that, The sludge co-degradation unit is specifically used for: The sludge is extracted and transported to the sludge activation reaction space by a sludge extraction structure set at the bottom of the staged anaerobic reaction unit to form a sludge circulation path. Shear disturbance treatment is performed on the deposited sludge in the sludge activation reaction space to break up the sludge floc structure and re-expose the microbial community and organic substrate in the deposited sludge. While performing floc destructive treatment, the deposited sludge is brought into contact with a microbial carrier loaded with hydrolytic and denitrifying bacteria to form a bio-attached structure and generate activated sludge. The generated activated sludge is recycled to the staged anaerobic reactor unit so that the activated sludge can participate in the anaerobic degradation process in the staged anaerobic reactor unit.

4. The system according to claim 1, characterized in that, The micro-oxygen enhancement reaction unit is specifically used for: Wastewater treated by the staged anaerobic reaction unit is introduced into the micro-aerobic enhanced reaction unit, and gas is supplied to the reaction space through the set micro-aeration structure to form a micro-bubble mixed flow. The control commands output by the circulation control unit are used to adjust the air supply of the micro-gas aeration structure, so that the reaction space is maintained in a controlled dissolved oxygen state, thereby constructing a facultative reaction environment. In the facultative reaction environment, the microbial community in the returned sludge performs biological oxidation and reduction transformation processes on nitrogenous pollutants in the wastewater. Wastewater that has undergone biological conversion treatment is transported to the deep purification unit.

5. The system according to claim 1, characterized in that, The deep purification unit is specifically used for: Wastewater treated by the micro-oxygen enhanced reaction unit is introduced into the deep purification unit, and the wastewater flows sequentially through the biological attached filter layer, the ion exchange adsorption layer and the carbon source release layer along a preset flow path. In the bio-attached filter media layer, a porous biological carrier is used to construct a bio-attachment interface, so that dissolved pollutants in wastewater can come into contact with and react with the attached microbial community to form a biotransformation process. Wastewater treated by the bio-attached filter layer is introduced into the ion exchange adsorption layer, where functionalized ion exchange materials are used to selectively exchange and adsorb ammonia nitrogen and dissolved ions in the wastewater. Wastewater treated by the ion exchange adsorption layer is introduced into the carbon source release layer. In the carbon source release layer, biodegradable carbon source is continuously released into the reaction water through slow-release solid carbon source material, so as to form an enhanced denitrification reaction environment in the deep purification unit.

6. The system according to claim 1, characterized in that, The cyclic control unit is specifically used for: Dissolved oxygen, oxidation-reduction potential, ammonia nitrogen concentration, and sludge concentration parameters are collected from the tiered anaerobic reaction unit, microaerobic enhanced reaction unit, and deep purification unit, and a system operation status feature vector is constructed based on the operating parameters. The system operating state feature vector is input into the adaptive operation and control model, and state determination and parameter optimization operations are performed in the adaptive operation and control model to generate corresponding coordinated control instructions. The sludge transport flow rate in the sludge return path is adjusted based on the aforementioned coordinated control command, and the oxygen supply intensity in the micro-aerobic enhanced reaction unit is adjusted simultaneously. The return ratio of the effluent from the deep purification unit is adjusted according to the coordinated control command to achieve coordinated adjustment of the operating parameters between the sludge return path, the micro-aerobic enhanced reaction unit, and the deep purification unit.

7. The system according to claim 6, characterized in that, The step of inputting the system operating state feature vector into the adaptive operation control model, and performing state determination and parameter optimization calculations in the adaptive operation control model to generate corresponding coordinated control instructions includes: The system's operating status feature vector is subjected to feature normalization processing, and a status evaluation result corresponding to the hierarchical anaerobic reaction unit, micro-aerobic enhanced reaction unit, and deep purification unit is generated based on the preset operating status evaluation rules. The state evaluation results are input into a multi-objective parameter optimization model. In the multi-objective parameter optimization model, the sludge return flow rate, oxygen supply intensity and deep purification unit return ratio are used as parameters to be adjusted to construct a parameter optimization space. Perform iterative optimization operations within the parameter optimization space to determine the target combination of operating parameters that matches the current system operating state; Based on the target combination of operating parameters, a coordinated control instruction is generated, and the coordinated control instruction is output to the cyclic control unit to perform system operating parameter adjustment.

8. The system according to claim 1, characterized in that, A gas-liquid disturbance component is installed in the sludge activation reaction space. The gas-liquid disturbance component is used to release microbubble airflow into the sludge activation reaction space and form a gas-liquid mixed disturbance flow, so that the deposited sludge entering the sludge activation reaction space forms a dispersed sludge structure under the action of gas-liquid shearing, and promotes the contact reaction between the deposited sludge and the microbial carrier.

9. The system according to claim 1, characterized in that, The microbial carrier is a porous biological carrier structure, and the surface of the porous biological carrier is loaded with a complex functional bacterial community, which includes hydrolytic bacteria, acid-producing bacteria and denitrifying bacteria, so as to form a stable biofilm structure in the sludge activation reaction space and participate in the anaerobic degradation reaction when the activated sludge is returned to the staged anaerobic reaction unit.

10. A method for deep purification of septic tank wastewater based on the synergistic sludge degradation of the system described in any one of claims 1 to 9, characterized in that, include: The wastewater is received after pretreatment and introduced into a staged anaerobic reaction unit, whereby the wastewater passes through a hydrolysis acidification zone, an acid production zone, and a methanogenic zone set along the water flow direction in sequence, so as to perform stepwise anaerobic transformation treatment on the organic pollutants in the wastewater. The sedimented sludge is extracted from the bottom of the graded anaerobic reaction unit and transported to the sludge activation reaction space. In the sludge activation reaction space, the sedimented sludge is subjected to floc destructive treatment and is brought into contact with the microbial carrier loaded with functional bacteria to generate activated sludge. The activated sludge is then returned to the graded anaerobic reaction unit. Wastewater treated by the staged anaerobic reaction unit is introduced into the micro-aerobic enhanced reaction unit to create a facultative reaction environment under controlled dissolved oxygen conditions, so that the microbial community in the returned sludge can carry out biotransformation reactions on nitrogen pollutants in the wastewater. Wastewater treated by the micro-oxygen enhanced reaction unit is introduced into the deep purification unit, where it passes through a biologically attached filter layer, an ion exchange adsorption layer, and a carbon source release layer in sequence to perform multi-stage filtration and adsorption treatment. The operating parameters of the graded anaerobic reaction unit, the micro-aerobic enhanced reaction unit, and the deep purification unit are collected, and the sludge transport flow rate in the sludge return path, the oxygen supply intensity in the micro-aerobic enhanced reaction unit, and the return ratio of the deep purification unit are adjusted based on the operating parameters.

Images