Method for purifying fishery breeding tail water based on mobile bed biofilm and electric oxygen cooperation

Abstract

This invention relates to the field of aquaculture wastewater purification, and discloses a method for purifying aquaculture wastewater based on a moving bed biofilm and electro-oxygen synergy. The method includes the following steps: pre-treating and homogenizing the aquaculture wastewater, then introducing it into a moving bed biofilm reactor to activate the suspended packing material; subsequently, in-situ oxygen production and enhanced electrochemical reaction through electro-oxygen synergy, combined with a stratified aerobic and anoxic structure to enhance nitrogen and phosphorus removal, and setting up a circulating reflux system for deep purification; finally, end-of-pipe solid-liquid separation and resource recovery. This invention overcomes the shortcomings of traditional wastewater treatment processes, such as low oxygen utilization, insufficient treatment load, and unstable nitrogen and phosphorus removal. Through the synergistic effect of the moving bed biofilm and the electro-oxygen system, it achieves efficient, low-consumption, and stable purification of aquaculture wastewater.

Description

Technical Field

[0001] This invention relates to the field of aquaculture wastewater purification, and in particular to a method for purifying aquaculture wastewater based on a moving bed biofilm and electro-oxygen synergy. Background Technology

[0002] With the large-scale and intensive development of aquaculture, the discharge of aquaculture wastewater has continued to rise. This wastewater is rich in ammonia nitrogen, nitrite, total phosphorus, and organic pollutants. Direct discharge can lead to eutrophication, disrupt the ecological balance of aquatic bodies, waste water resources, and hinder the green and sustainable development of aquaculture. Currently, the purification of aquaculture wastewater mainly adopts traditional biological treatment technologies, such as activated sludge and fixed-bed biofilm processes. However, the activated sludge process suffers from problems such as easy sludge loss, low treatment load, and poor adaptability to low temperatures and water quality fluctuations. It also requires frequent sludge removal, which can easily cause secondary pollution. While the fixed-bed biofilm process can stably form a biofilm, the packing material is prone to clogging, has low mass transfer efficiency, and a long biofilm renewal cycle, making it difficult to consistently meet treatment standards for high-concentration aquaculture wastewater. In addition, traditional aeration methods are energy-intensive and have low oxygen utilization rates, failing to provide sufficient dissolved oxygen for biofilm degradation of pollutants, further limiting purification efficiency and treatment stability.

[0003] To address these issues, some technologies have attempted to optimize biofilm carriers or improve aeration methods, but significant shortcomings remain. While moving bed biofilm technology achieves efficient biofilm renewal through suspended packing, increasing treatment load, it still relies on mechanical aeration, resulting in insufficient oxygen transfer efficiency. Furthermore, when treating aquaculture wastewater containing high ammonia nitrogen and organic matter, it is prone to problems such as insufficient nitrifying bacteria activity and unstable nitrogen and phosphorus removal effects. While single electrochemical purification technology can generate oxygen through electrolysis and degrade pollutants through oxidation, it suffers from high energy consumption, poor biocompatibility, and difficulty in simultaneously achieving efficient nitrogen and phosphorus removal and organic pollutant degradation. Moreover, when used alone, its efficiency in removing nutrients from wastewater is limited, failing to meet the stringent requirements for compliant discharge of aquaculture wastewater.

[0004] The aquaculture wastewater purification method proposed in this patent, based on moving bed biofilm and electro-oxygen synergy, can specifically address the core pain points of existing technologies. Summary of the Invention

[0005] This invention overcomes the shortcomings of the prior art and provides a method for purifying aquaculture wastewater based on moving bed biofilm and electro-oxygen synergy.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: The first aspect of this invention provides a method for purifying aquaculture wastewater based on a moving bed biofilm and electro-oxygen synergy, comprising the following steps: The wastewater from aquaculture is pretreated and homogenized. A moving bed biofilm reactor was introduced, and pretreated aquaculture wastewater was introduced. Simultaneously, activated suspended packing material was used to treat the wastewater, resulting in pretreated biofilm wastewater. For biofilm pretreatment effluent, electro-oxygen coordinated in-situ oxygen generation treatment and electrochemical enhanced reaction treatment are carried out to obtain electro-oxygen enhanced biochemical effluent. The biochemical wastewater enhanced by oxygenation is subjected to stratified microbial community enhancement for nitrogen and phosphorus removal and targeted degradation, and then subjected to cyclic reflux for enhanced efficiency, resulting in deeply purified and reusable wastewater. The wastewater undergoes end-of-pipe solid-liquid separation and resource recovery for deep purification and reuse, thus completing the wastewater purification process.

[0007] Furthermore, in a preferred embodiment of the present invention, the pretreatment of aquaculture wastewater and the homogenization and conditioning of the wastewater specifically involve: Identify the storage pond for aquaculture wastewater, mark it as the aquaculture wastewater storage pond, and obtain the aquaculture wastewater regulating pond. Connect the aquaculture wastewater storage pond and the aquaculture wastewater regulating pond with pipelines. Impurities are intercepted in the aquaculture wastewater in the pipeline. The targets of impurity interception are large suspended solids and floating debris carried in the aquaculture wastewater. The impurity interception method is mechanical interception, and the impurities are regularly collected and cleaned during the impurity interception process. An online monitoring sensor group is deployed in the aquaculture wastewater regulation tank to monitor the temperature, pH value, ammonia nitrogen concentration, chemical oxygen demand and dissolved oxygen concentration of the aquaculture wastewater after impurity interception in real time, and to obtain the wastewater control system and store the monitoring data of the online monitoring sensor group in real time. By introducing a historical data network, the tailwater quality adjustment methods under the monitoring data of different online monitoring sensor groups are retrieved and output in real time to ensure that the monitoring data of the online monitoring sensor groups are in a state of homogeneous and stable water quality in real time. Fishery aquaculture wastewater in a homogeneous and stable state is designated as pretreated fishery aquaculture wastewater.

[0008] Furthermore, in a preferred embodiment of the present invention, the introduction of the moving bed biofilm reactor and the introduction of pretreated aquaculture wastewater, along with the simultaneous activation of suspended packing material to obtain pretreated biofilm wastewater, specifically involves: A moving bed biofilm reactor is introduced, and pretreated aquaculture wastewater is introduced into it. At the same time, the inflow rate of the pretreated aquaculture wastewater is controlled to maintain a predetermined value until the pretreated aquaculture wastewater reaches the preset water level in the moving bed biofilm reactor. In the moving bed biofilm reactor, polyethylene modified porous suspended packing is added, and after addition, a low-speed fluidized aeration device is activated in the moving bed biofilm reactor to fluidize the polyethylene modified porous suspended packing until the fluidization time reaches the preset time and then the fluidization is stopped. During the fluidized bed treatment process, the pretreated aquaculture wastewater is sampled in real time to obtain wastewater samples. Colony microbial enrichment analysis is performed on the wastewater samples in real time. The colony microbial enrichment analysis involves detecting the content of surface nitrifying bacteria, denitrifying bacteria and polyphosphate-accumulating bacteria in the wastewater samples. If the surface content of nitrifying bacteria, denitrifying bacteria and polyphosphate-accumulating bacteria on the wastewater sample reaches the standard value, it is determined that a stable biofilm has formed in the pretreated aquaculture wastewater. Simultaneously, an online monitoring sensor array is deployed within the moving bed biofilm reactor and connected to the effluent control system; The system retrieves monitoring data from the online monitoring sensor group through the effluent control system, imports the corresponding data into the historical data network, retrieves the fluidization stirring intensity corresponding to different real-time concentrations of ammonia nitrogen and chemical oxygen demand, and outputs it into the moving bed biofilm reactor to obtain biofilm pretreated effluent.

[0009] Furthermore, in a preferred embodiment of the present invention, the process of subjecting the biofilm pretreatment effluent to electro-oxygen coordinated in-situ oxygen generation treatment and electrochemically enhanced reaction treatment to obtain electro-oxygen enhanced biochemical effluent specifically involves: In the moving bed biofilm reactor, a pair of low-voltage DC electrolysis electrodes is deployed, and the low-voltage DC electrolysis electrodes are electrically connected to the effluent control system. Based on the online monitoring sensor group, the concentrations of dissolved oxygen, ammonia nitrogen and chemical oxygen demand in the moving bed biofilm reactor are monitored in real time. The effluent control system automatically matches low-voltage DC power according to the concentrations of dissolved oxygen, ammonia nitrogen and chemical oxygen demand. The tailwater control system is connected to a historical data network, and based on the historical data network, it retrieves the output voltage of low-voltage DC power corresponding to different concentrations of dissolved oxygen, ammonia nitrogen, and chemical oxygen demand. When the tailwater control system automatically matches the low-voltage DC power, the low-voltage DC electrolysis electrode pairs perform water electrolysis reaction in the biofilm pretreatment tailwater to generate dissolved oxygen and active oxides. The dissolved oxygen generated after the water electrolysis reaction is then used to re-fluidize the polyethylene modified porous suspended packing material for oxygen supply to stabilize the biofilm. The oxidation-reduction potential of the biofilm pretreatment effluent is monitored in real time by the effluent control system when low-voltage DC power is output. The output voltage is adjusted in real time according to the concentrations of dissolved oxygen, ammonia nitrogen and chemical oxygen demand to obtain electro-oxygen-enhanced biochemical effluent.

[0010] Furthermore, in a preferred embodiment of the present invention, the step of performing microbial stratification-enhanced denitrification and phosphorus removal targeted degradation on the electro-oxygen-enhanced biochemical effluent, followed by cyclic reflux for enhanced efficiency, to obtain deeply purified and reusable effluent, specifically involves: Within the moving bed biofilm reactor, an outer aerobic zone and an inner anoxic zone are defined. The method of division is to divide the moving bed biofilm reactor into grids and sample each grid for testing. The concentrations of ammonia nitrogen, nitrate nitrogen, total phosphorus and dissolved oxygen obtained from the sampling monitoring are used to divide the outer aerobic zone and the inner anoxic zone. The online monitoring sensor group is activated to monitor the concentrations of ammonia nitrogen, nitrate nitrogen, total phosphorus and dissolved oxygen in the electro-oxygen-enhanced biological wastewater in real time and transmit the data to the wastewater control system. In the historical data network, the sulfidation disturbance intensity and electrolytic oxygen supply intensity corresponding to different concentrations of ammonia nitrogen, nitrate nitrogen, total phosphorus and dissolved oxygen are retrieved and matched to determine the reaction conditions of the outer aerobic region and the inner anoxic region. The reaction conditions in the outer aerobic zone are used for nitrification degradation of the electro-oxygen-enhanced biological wastewater, while the reaction conditions in the inner anoxic zone are used for the removal of reactants from the electro-oxygen-enhanced biological wastewater after nitrification degradation, thus completing simultaneous denitrification. After simultaneous denitrification, targeted phosphorus removal is carried out in the moving bed biofilm reactor. The electro-oxygen-enhanced biological wastewater after simultaneous denitrification and targeted phosphorus removal is mixed with the electro-oxygen-enhanced biological wastewater before simultaneous denitrification and targeted phosphorus removal, and then subjected to electrochemical enhanced reaction treatment again to achieve circulation and reflux, resulting in circulated enhanced purified wastewater. For the wastewater from the enhanced purification process, a recirculation and reflux treatment is carried out to obtain deeply purified and reused wastewater.

[0011] Furthermore, in a preferred embodiment of the present invention, the step of performing a recirculation enhancement treatment on the effluent from the enhanced purification process to obtain deeply purified and reused effluent specifically involves: During the recirculation process, the recirculation ratio under different combinations of ammonia nitrogen, nitrate nitrogen, total phosphorus and dissolved oxygen concentrations is retrieved through the tailwater control system combined with historical data network. The recirculation ratio is the ratio of the electro-oxygen-enhanced biological tailwater before and after the simultaneous denitrification and targeted phosphorus removal treatment. The recirculation ratio is adjusted in real time, and during the adjustment process, the circulating enhanced purification effluent is subjected to deep oxidation and decomposition through a low-voltage DC electrolysis electrode pair. The online monitoring sensor group of the tailwater control system monitors the concentrations of ammonia nitrogen, nitrate nitrogen, total phosphorus and dissolved oxygen in the circulating enhanced purification tailwater in real time. When the preset purification standard is reached, the circulating enhanced purification tailwater is marked as deep purification and reuse tailwater.

[0012] Furthermore, in a preferred embodiment of the present invention, the step of performing end-of-pipe solid-liquid separation and resource recovery on the deep-purified and reused effluent to complete the effluent purification specifically involves: A fine separation zone is set up within the moving bed biofilm reactor; Through the fine separation zone, the deep-purified reuse effluent undergoes end-of-pipe solid-liquid separation treatment. The end-of-pipe solid-liquid separation treatment involves using microporous filter media to create a biofilm and intercept solids in the deep-purified reuse effluent, resulting in solid-liquid separated effluent and solid-liquid separated residue. The solid-liquid separation residue is treated to render it harmless, and the solid-liquid separation tailwater is discharged externally to complete the tailwater purification treatment.

[0013] This invention addresses the technical deficiencies in the prior art and offers the following beneficial effects: It pre-treats and homogenizes aquaculture wastewater before introducing it into a moving bed biofilm reactor to activate suspended packing material; subsequently, it enhances in-situ oxygen production and electrochemical reactions through electro-oxygen synergy, strengthens nitrogen and phosphorus removal through a stratified aerobic and anoxic structure, and incorporates a circulating reflux system for deep purification; finally, it performs end-of-pipe solid-liquid separation and resource recovery. This invention overcomes the shortcomings of traditional wastewater treatment processes, such as low oxygen utilization, insufficient treatment load, and unstable nitrogen and phosphorus removal. Through the synergistic effect of the moving bed biofilm and the electro-oxygen system, it achieves efficient, low-consumption, and stable purification of aquaculture wastewater. Attached Figure Description

[0014] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other embodiments can be obtained from these drawings without creative effort.

[0015] Figure 1 A flowchart of a method for purifying aquaculture wastewater based on moving bed biofilm and electro-oxygen synergy is shown. Figure 2 A flowchart illustrating a method for obtaining deeply purified and reused wastewater is shown. Detailed Implementation

[0016] To better understand the above-mentioned objectives, features, and advantages of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0017] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and therefore the scope of protection of the invention is not limited to the specific embodiments disclosed below.

[0018] Figure 1 A flowchart illustrating a method for purifying aquaculture wastewater based on a moving bed biofilm and electro-oxygen synergy is shown, including the following steps: The first aspect of this invention provides a method for purifying aquaculture wastewater based on a moving bed biofilm and electro-oxygen synergy, comprising the following steps: S102: Pre-treat the wastewater from aquaculture and homogenize and adjust the wastewater quality. S104: Introduce a moving bed biofilm reactor and introduce pretreated aquaculture wastewater, while simultaneously activating the suspended packing material to obtain pretreated biofilm wastewater. S106: For biofilm pretreatment effluent, electro-oxygen coordinated in-situ oxygen generation treatment and electrochemical enhanced reaction treatment are carried out to obtain electro-oxygen enhanced biochemical effluent. S108: The electro-oxygen-enhanced biochemical effluent undergoes stratified microbial denitrification and phosphorus removal with targeted degradation, followed by cyclic reflux for enhanced efficiency, resulting in deeply purified and reusable effluent. S110: Performs end-of-pipe solid-liquid separation and resource reuse on the deep-purified and reused effluent to complete the effluent purification.

[0019] Furthermore, in a preferred embodiment of the present invention, the pretreatment of aquaculture wastewater and the homogenization and conditioning of the wastewater specifically involve: Identify the storage pond for aquaculture wastewater, mark it as the aquaculture wastewater storage pond, and obtain the aquaculture wastewater regulating pond. Connect the aquaculture wastewater storage pond and the aquaculture wastewater regulating pond with pipelines. Impurities are intercepted in the aquaculture wastewater in the pipeline. The targets of impurity interception are large suspended solids and floating debris carried in the aquaculture wastewater. The impurity interception method is mechanical interception, and the impurities are regularly collected and cleaned during the impurity interception process. An online monitoring sensor group is deployed in the aquaculture wastewater regulation tank to monitor the temperature, pH value, ammonia nitrogen concentration, chemical oxygen demand and dissolved oxygen concentration of the aquaculture wastewater after impurity interception in real time, and to obtain the wastewater control system and store the monitoring data of the online monitoring sensor group in real time. By introducing a historical data network, the tailwater quality adjustment methods under the monitoring data of different online monitoring sensor groups are retrieved and output in real time to ensure that the monitoring data of the online monitoring sensor groups are in a state of homogeneous and stable water quality in real time. Fishery aquaculture wastewater in a homogeneous and stable state is designated as pretreated fishery aquaculture wastewater.

[0020] It should be noted that, firstly, the aquaculture wastewater storage tank and the equalization tank need to be connected through a dedicated pipeline to achieve centralized and orderly transportation of wastewater, ensuring a closed and controllable process and reducing the risk of external pollution and water leakage. Large particles and floating debris such as uneaten feed, feces, and algae are mechanically intercepted in the pipeline, and these are regularly cleaned. Multi-parameter sensors are deployed to monitor wastewater temperature, pH, ammonia nitrogen concentration, chemical oxygen demand (COD), and dissolved oxygen concentration in real time, enabling digital management of aquaculture wastewater quality. Finally, a historical database exists in the historical data network. Linking this database with real-time control enables intelligent and homogeneous water distribution, which is more efficient and stable than traditional experience-based or manual adjustments.

[0021] Furthermore, in a preferred embodiment of the present invention, the introduction of the moving bed biofilm reactor and the introduction of pretreated aquaculture wastewater, along with the simultaneous activation of suspended packing material to obtain pretreated biofilm wastewater, specifically involves: A moving bed biofilm reactor is introduced, and pretreated aquaculture wastewater is introduced into it. At the same time, the inflow rate of the pretreated aquaculture wastewater is controlled to maintain a predetermined value until the pretreated aquaculture wastewater reaches the preset water level in the moving bed biofilm reactor. In the moving bed biofilm reactor, polyethylene modified porous suspended packing is added, and after addition, a low-speed fluidized aeration device is activated in the moving bed biofilm reactor to fluidize the polyethylene modified porous suspended packing until the fluidization time reaches the preset time and then the fluidization is stopped. During the fluidized bed treatment process, the pretreated aquaculture wastewater is sampled in real time to obtain wastewater samples. Colony microbial enrichment analysis is performed on the wastewater samples in real time. The colony microbial enrichment analysis involves detecting the content of surface nitrifying bacteria, denitrifying bacteria and polyphosphate-accumulating bacteria in the wastewater samples. If the surface content of nitrifying bacteria, denitrifying bacteria and polyphosphate-accumulating bacteria on the wastewater sample reaches the standard value, it is determined that a stable biofilm has formed in the pretreated aquaculture wastewater. Simultaneously, an online monitoring sensor array is deployed within the moving bed biofilm reactor and connected to the effluent control system; The system retrieves monitoring data from the online monitoring sensor group through the effluent control system, imports the corresponding data into the historical data network, retrieves the fluidization stirring intensity corresponding to different real-time concentrations of ammonia nitrogen and chemical oxygen demand, and outputs it into the moving bed biofilm reactor to obtain biofilm pretreated effluent.

[0022] It should be noted that the introduction of a dedicated moving bed biofilm reactor allows for the treatment of effluent. Strict control of the influent velocity is crucial to prevent excessively rapid flow from dispersing the subsequently added packing material and to prevent overflow due to excessively high water levels or exposure of the packing material due to excessively low water levels, ensuring process continuity. Polyethylene-modified porous suspended packing material is added to the reactor, and a low-speed fluidized bed aeration system is activated to fluidize the packing material until the preset fluidization time is reached. The polyethylene-modified porous suspended packing material serves as the biofilm carrier. Fluidization ensures the packing material is evenly dispersed in the effluent, preventing packing material accumulation and caking, and ensuring sufficient contact between the packing material and the effluent. Furthermore, the polyethylene-modified packing material has a high specific surface area and strong biocompatibility, facilitating microbial adhesion. Low-speed fluidization ensures the packing material remains suspended throughout the reactor while preventing excessively high flow rates from damaging the subsequently formed biofilm. Simultaneously, aeration provides initial dissolved oxygen, laying the groundwork for microbial activation. Preset time control ensures effective fluidization, avoiding excessive fluidization leading to energy waste or insufficient fluidization causing packing material sedimentation.

[0023] Real-time sampling of effluent samples allows for microbial enrichment analysis. Three types of microorganisms are key to the biofilm's degradation of nitrogen, phosphorus, and organic matter in the effluent. Real-time monitoring of their content accurately determines the biofilm's enrichment status, avoiding blindly waiting for biofilm formation. If the levels of nitrifying bacteria, denitrifying bacteria, and polyphosphate-accumulating bacteria on the effluent sample surface reach preset standard values, it is determined that a stable biofilm has formed on the packing material surface, preventing the biofilm from entering the next process before it is stable. Finally, an online monitoring sensor group is added to the reaction tank to synchronize monitoring data to the control system, achieving data closed-loop. By intelligently controlling the fluidized bed stirring intensity, the mass transfer efficiency between the packing material and the effluent is enhanced, ensuring the initial degradation of ammonia nitrogen and organic matter in the effluent by the biofilm. This provides stable biofilm pretreated effluent for subsequent electro-oxygen synergistic enhanced reactions.

[0024] Furthermore, in a preferred embodiment of the present invention, the process of subjecting the biofilm pretreatment effluent to electro-oxygen coordinated in-situ oxygen generation treatment and electrochemically enhanced reaction treatment to obtain electro-oxygen enhanced biochemical effluent specifically involves: In the moving bed biofilm reactor, a pair of low-voltage DC electrolysis electrodes is deployed, and the low-voltage DC electrolysis electrodes are electrically connected to the effluent control system. Based on the online monitoring sensor group, the concentrations of dissolved oxygen, ammonia nitrogen and chemical oxygen demand in the moving bed biofilm reactor are monitored in real time. The effluent control system automatically matches low-voltage DC power according to the concentrations of dissolved oxygen, ammonia nitrogen and chemical oxygen demand. The tailwater control system is connected to a historical data network, and based on the historical data network, it retrieves the output voltage of low-voltage DC power corresponding to different concentrations of dissolved oxygen, ammonia nitrogen, and chemical oxygen demand. When the tailwater control system automatically matches the low-voltage DC power, the low-voltage DC electrolysis electrode pairs perform water electrolysis reaction in the biofilm pretreatment tailwater to generate dissolved oxygen and active oxides. The dissolved oxygen generated after the water electrolysis reaction is then used to re-fluidize the polyethylene modified porous suspended packing material for oxygen supply to stabilize the biofilm. The oxidation-reduction potential of the biofilm pretreatment effluent is monitored in real time by the effluent control system when low-voltage DC power is output. The output voltage is adjusted in real time according to the concentrations of dissolved oxygen, ammonia nitrogen and chemical oxygen demand to obtain electro-oxygen-enhanced biochemical effluent.

[0025] It should be noted that low-voltage DC electrolysis electrodes offer high equipment integration, small footprint, and low investment. Low-voltage DC electrodes also boast high safety and low energy consumption, providing a hardware foundation for biochemical degradation and electrochemical enhancement, enabling in-situ oxygen production and oxidative degradation. Since the low-voltage DC electrolysis electrodes require adjustable power supply modes, dissolved oxygen, ammonia nitrogen, and chemical oxygen demand (COD) concentrations are collected in real time. The effluent control system automatically matches the appropriate low-voltage DC power supply mode based on this real-time data. Advantages include fast response, precise adjustment, and no need for manual monitoring; dynamic power supply based on pollution load significantly reduces energy consumption. After obtaining the optimal electrolysis voltage, the electrodes electrolyze water in the biofilm pretreatment effluent, generating high-purity dissolved oxygen and active oxides such as hydroxyl radicals. Simultaneously, the electrolysis-generated gas agitates the water body, again fluidizing the polyethylene-modified porous suspended packing and efficiently supplying oxygen to the biofilm. The advantages are: oxygen utilization rate is far higher than traditional aeration, with almost no oxygen waste; electrolysis-generated gas assists fluidization, reducing aeration energy consumption; and active oxygen can pretreat recalcitrant substances, improving subsequent biochemical efficiency. Finally, the output voltage is adjusted in real time based on the concentrations of dissolved oxygen, ammonia nitrogen, and chemical oxygen demand to obtain electro-oxygen-enhanced biochemical effluent.

[0026] Furthermore, in a preferred embodiment of the present invention, the step of performing end-of-pipe solid-liquid separation and resource recovery on the deep-purified and reused effluent to complete the effluent purification specifically involves: A fine separation zone is set up within the moving bed biofilm reactor; Through the fine separation zone, the deep-purified reuse effluent undergoes end-of-pipe solid-liquid separation treatment. The end-of-pipe solid-liquid separation treatment involves using microporous filter media to create a biofilm and intercept solids in the deep-purified reuse effluent, resulting in solid-liquid separated effluent and solid-liquid separated residue. The solid-liquid separation residue is treated to render it harmless, and the solid-liquid separation tailwater is discharged externally to complete the tailwater purification treatment.

[0027] It should be noted that the fine separation zone is used for end-of-pipe separation, providing a dedicated solid-liquid separation space for deeply purified and reused effluent. This thoroughly separates aging and detached biofilm and trace suspended solids from the clean water, ensuring the final effluent is clear and transparent. There is no need to construct separate sedimentation tanks or filtration tanks; existing tanks are fully utilized, resulting in a small footprint, low project investment, and simple piping connections. Subsequently, the microporous filter media achieves high interception precision, producing clear effluent; it can directly trap aging biofilm, preventing it from flowing out with the effluent and causing secondary pollution; it has low operating resistance, is not prone to clogging, and is easy to maintain, ultimately yielding solid-liquid separated effluent.

[0028] Figure 2 A flowchart illustrating a method for obtaining deeply purified and reused effluent is shown, including the following steps: S202: The electro-oxygen-enhanced biochemical effluent undergoes stratified microbial denitrification, phosphorus removal, and targeted degradation, followed by cyclic reflux for enhanced efficiency, resulting in deeply purified and reusable effluent. S204: For the effluent from the enhanced purification process, a recirculation and reflux treatment is carried out to obtain deeply purified and reused effluent.

[0029] Furthermore, in a preferred embodiment of the present invention, the step of performing microbial stratification-enhanced denitrification and phosphorus removal targeted degradation on the electro-oxygen-enhanced biochemical effluent, followed by cyclic reflux for enhanced efficiency, to obtain deeply purified and reusable effluent, specifically involves: Within the moving bed biofilm reactor, an outer aerobic zone and an inner anoxic zone are defined. The method of division is to divide the moving bed biofilm reactor into grids and sample each grid for testing. The concentrations of ammonia nitrogen, nitrate nitrogen, total phosphorus and dissolved oxygen obtained from the sampling monitoring are used to divide the outer aerobic zone and the inner anoxic zone. The online monitoring sensor group is activated to monitor the concentrations of ammonia nitrogen, nitrate nitrogen, total phosphorus and dissolved oxygen in the electro-oxygen-enhanced biological wastewater in real time and transmit the data to the wastewater control system. In the historical data network, the sulfidation disturbance intensity and electrolytic oxygen supply intensity corresponding to different concentrations of ammonia nitrogen, nitrate nitrogen, total phosphorus and dissolved oxygen are retrieved and matched to determine the reaction conditions of the outer aerobic region and the inner anoxic region. The reaction conditions in the outer aerobic zone are used for nitrification degradation of the electro-oxygen-enhanced biological wastewater, while the reaction conditions in the inner anoxic zone are used for the removal of reactants from the electro-oxygen-enhanced biological wastewater after nitrification degradation, thus completing simultaneous denitrification. After simultaneous denitrification, targeted phosphorus removal is carried out in the moving bed biofilm reactor. The electro-oxygen-enhanced biological wastewater after simultaneous denitrification and targeted phosphorus removal is mixed with the electro-oxygen-enhanced biological wastewater before simultaneous denitrification and targeted phosphorus removal, and then subjected to electrochemical enhanced reaction treatment again to achieve circulation and reflux, resulting in circulated enhanced purified wastewater. For the wastewater from the enhanced purification process, a recirculation and reflux treatment is carried out to obtain deeply purified and reused wastewater.

[0030] It should be noted that within the same moving bed biofilm reactor, an external high-oxygen aerobic zone and an internal low-oxygen anoxic zone are artificially divided based on dissolved oxygen distribution and packing material location. The aim is to simultaneously construct the environments required for nitrification and denitrification within a single reactor, achieving synchronous nitrogen removal. The zone is precisely and quantitatively categorized based on concentration thresholds to determine whether it belongs to the aerobic or anoxic zone. Reaction conditions ensure sufficient oxygen supply to the aerobic zone to enhance nitrification, while maintaining a low-oxygen environment in the anoxic zone to guarantee denitrification, achieving a precise match between the environment and bacterial community function. Specifically, in the outer aerobic zone, dissolved oxygen generated in situ by electrolysis enhances the metabolism of nitrifying bacteria on the biofilm surface, gradually oxidizing ammonia nitrogen and nitrite nitrogen in the electro-oxygenated biochemical effluent to nitrate nitrogen, completing nitrification degradation. In the inner anoxic zone, organic pollutants in the effluent serve as a carbon source, driving the denitrifying bacteria within the biofilm to reduce nitrate nitrogen to nitrogen gas and remove it from the water, completing synchronous denitrification. Subsequently, the trace metal ions generated by electrolysis, combined with the synergistic enrichment effect of polyphosphate-accumulating bacteria, convert dissolved phosphorus in the water into solid phosphates and fix them on the surface of the biofilm and packing material, achieving targeted phosphorus removal. The water that has undergone nitrogen and phosphorus removal treatment is then returned to the front end of the moving bed biofilm reactor according to a preset return ratio, mixed with the effluent to be treated, and subjected to fluidized reaction and electro-oxygen-enhanced purification again to obtain circulated enhanced purified effluent.

[0031] Furthermore, in a preferred embodiment of the present invention, the step of performing a recirculation enhancement treatment on the effluent from the enhanced purification process to obtain deeply purified and reused effluent specifically involves: During the recirculation process, the recirculation ratio under different combinations of ammonia nitrogen, nitrate nitrogen, total phosphorus and dissolved oxygen concentrations is retrieved through the tailwater control system combined with historical data network. The recirculation ratio is the ratio of the electro-oxygen-enhanced biological tailwater before and after the simultaneous denitrification and targeted phosphorus removal treatment. The recirculation ratio is adjusted in real time, and during the adjustment process, the circulating enhanced purification effluent is subjected to deep oxidation and decomposition through a low-voltage DC electrolysis electrode pair. The online monitoring sensor group of the tailwater control system monitors the concentrations of ammonia nitrogen, nitrate nitrogen, total phosphorus and dissolved oxygen in the circulating enhanced purification tailwater in real time. When the preset purification standard is reached, the circulating enhanced purification tailwater is marked as deep purification and reuse tailwater.

[0032] It should be noted that dynamically determining the internal circulation intensity based on real-time pollution load, and avoiding insufficient purification or energy waste caused by a fixed recirculation ratio, is key to the recirculation ratio retrieval. An adaptive adjustment of the recirculation ratio with water quality results in a higher degree of matching with the treatment load, avoiding short-circuiting, dead zones, or over-circulation, and improving hydraulic utilization efficiency. The control system adjusts the recirculation ratio in real time based on the retrieval results, and, combined with a low-voltage DC electrolysis electrode pair, continuously and deeply oxidizes the circulating water, decomposing residual organic matter, trace amounts of nitrite, and other recalcitrant pollutants, thus compensating for the slow degradation rate of low-concentration pollutants by biofilm reactions.

[0033] The above are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for purifying aquaculture wastewater based on moving bed biofilm and electro-oxygen synergy, characterized in that, Includes the following steps: The wastewater from aquaculture is pretreated and homogenized. A moving bed biofilm reactor was introduced, and pretreated aquaculture wastewater was introduced. Simultaneously, activated suspended packing material was used to treat the wastewater, resulting in pretreated biofilm wastewater. For biofilm pretreatment effluent, electro-oxygen coordinated in-situ oxygen generation treatment and electrochemical enhanced reaction treatment are carried out to obtain electro-oxygen enhanced biochemical effluent. The biochemical wastewater enhanced by oxygenation is subjected to stratified microbial community enhancement for nitrogen and phosphorus removal and targeted degradation, and then subjected to cyclic reflux for enhanced efficiency, resulting in deeply purified and reusable wastewater. The wastewater undergoes end-of-pipe solid-liquid separation and resource recovery for deep purification and reuse, thus completing the wastewater purification process.

2. The method for purifying aquaculture wastewater based on moving bed biofilm and electro-oxygen synergy as described in claim 1, characterized in that, The aforementioned pretreatment of aquaculture wastewater and homogenization of the wastewater specifically involves: Identify the storage pond for aquaculture wastewater, mark it as the aquaculture wastewater storage pond, and obtain the aquaculture wastewater regulating pond. Connect the aquaculture wastewater storage pond and the aquaculture wastewater regulating pond with pipelines. Impurities are intercepted in the aquaculture wastewater in the pipeline. The targets of impurity interception are large suspended solids and floating debris carried in the aquaculture wastewater. The impurity interception method is mechanical interception, and the impurities are regularly collected and cleaned during the impurity interception process. An online monitoring sensor group is deployed in the aquaculture wastewater regulation tank to monitor the temperature, pH value, ammonia nitrogen concentration, chemical oxygen demand and dissolved oxygen concentration of the aquaculture wastewater after impurity interception in real time, and to obtain the wastewater control system and store the monitoring data of the online monitoring sensor group in real time. By introducing a historical data network, the tailwater quality adjustment methods under the monitoring data of different online monitoring sensor groups are retrieved and output in real time to ensure that the monitoring data of the online monitoring sensor groups are in a state of homogeneous and stable water quality in real time. Fishery aquaculture wastewater in a homogeneous and stable state is designated as pretreated fishery aquaculture wastewater.

3. The method for purifying aquaculture wastewater based on moving bed biofilm and electro-oxygen synergy as described in claim 1, characterized in that, The process involves introducing a moving bed biofilm reactor and introducing pretreated aquaculture wastewater, while simultaneously activating the suspended packing material to obtain pretreated biofilm wastewater. Specifically: A moving bed biofilm reactor is introduced, and pretreated aquaculture wastewater is introduced into it. At the same time, the inflow rate of the pretreated aquaculture wastewater is controlled to maintain a predetermined value until the pretreated aquaculture wastewater reaches the preset water level in the moving bed biofilm reactor. In the moving bed biofilm reactor, polyethylene modified porous suspended packing is added, and after addition, a low-speed fluidized aeration device is activated in the moving bed biofilm reactor to fluidize the polyethylene modified porous suspended packing until the fluidization time reaches the preset time and then the fluidization is stopped. During the fluidized bed treatment process, the pretreated aquaculture wastewater is sampled in real time to obtain wastewater samples. Colony microbial enrichment analysis is performed on the wastewater samples in real time. The colony microbial enrichment analysis involves detecting the content of surface nitrifying bacteria, denitrifying bacteria and polyphosphate-accumulating bacteria in the wastewater samples. If the surface content of nitrifying bacteria, denitrifying bacteria and polyphosphate-accumulating bacteria on the wastewater sample reaches the standard value, it is determined that a stable biofilm has formed in the pretreated aquaculture wastewater. Simultaneously, an online monitoring sensor array is deployed within the moving bed biofilm reactor and connected to the effluent control system; The system retrieves monitoring data from the online monitoring sensor group through the effluent control system, imports the corresponding data into the historical data network, retrieves the fluidization stirring intensity corresponding to different real-time concentrations of ammonia nitrogen and chemical oxygen demand, and outputs it into the moving bed biofilm reactor to obtain biofilm pretreated effluent.

4. The method for purifying aquaculture wastewater based on moving bed biofilm and electro-oxygen synergy as described in claim 1, characterized in that, The pretreated effluent from the biofilm undergoes a combination of electro-oxygen coordinated in-situ oxygen generation treatment and electrochemical enhanced reaction treatment to obtain electro-oxygen enhanced biochemical effluent, specifically as follows: In the moving bed biofilm reactor, a pair of low-voltage DC electrolysis electrodes is deployed, and the low-voltage DC electrolysis electrodes are electrically connected to the effluent control system. Based on the online monitoring sensor group, the concentrations of dissolved oxygen, ammonia nitrogen and chemical oxygen demand in the moving bed biofilm reactor are monitored in real time. The effluent control system automatically matches low-voltage DC power according to the concentrations of dissolved oxygen, ammonia nitrogen and chemical oxygen demand. The tailwater control system is connected to a historical data network, and based on the historical data network, it retrieves the output voltage of low-voltage DC power corresponding to different concentrations of dissolved oxygen, ammonia nitrogen, and chemical oxygen demand. When the tailwater control system automatically matches the low-voltage DC power, the low-voltage DC electrolysis electrode pairs perform water electrolysis reaction in the biofilm pretreatment tailwater to generate dissolved oxygen and active oxides. The dissolved oxygen generated after the water electrolysis reaction is then used to re-fluidize the polyethylene modified porous suspended packing material for oxygen supply to stabilize the biofilm. The oxidation-reduction potential of the biofilm pretreatment effluent is monitored in real time by the effluent control system when low-voltage DC power is output. The output voltage is adjusted in real time according to the concentrations of dissolved oxygen, ammonia nitrogen and chemical oxygen demand to obtain electro-oxygen-enhanced biochemical effluent.

5. The method for purifying aquaculture wastewater based on moving bed biofilm and electro-oxygen synergy as described in claim 1, characterized in that, The process involves stratified microbial denitrification, phosphorus removal, and targeted degradation of the electro-oxygen-enhanced biochemical effluent, followed by cyclic reflux for enhanced efficiency, to obtain deeply purified and reusable effluent. Specifically: Within the moving bed biofilm reactor, an outer aerobic zone and an inner anoxic zone are defined. The method of division is to divide the moving bed biofilm reactor into grids and sample each grid for testing. The concentrations of ammonia nitrogen, nitrate nitrogen, total phosphorus and dissolved oxygen obtained from the sampling monitoring are used to divide the outer aerobic zone and the inner anoxic zone. The online monitoring sensor group is activated to monitor the concentrations of ammonia nitrogen, nitrate nitrogen, total phosphorus and dissolved oxygen in the electro-oxygen-enhanced biological wastewater in real time and transmit the data to the wastewater control system. In the historical data network, the sulfidation disturbance intensity and electrolytic oxygen supply intensity corresponding to different concentrations of ammonia nitrogen, nitrate nitrogen, total phosphorus and dissolved oxygen are retrieved and matched to determine the reaction conditions of the outer aerobic region and the inner anoxic region. The reaction conditions in the outer aerobic zone are used for nitrification degradation of the electro-oxygen-enhanced biological wastewater, while the reaction conditions in the inner anoxic zone are used for the removal of reactants from the electro-oxygen-enhanced biological wastewater after nitrification degradation, thus completing simultaneous denitrification. After simultaneous denitrification, targeted phosphorus removal is carried out in the moving bed biofilm reactor. The electro-oxygen-enhanced biological wastewater after simultaneous denitrification and targeted phosphorus removal is mixed with the electro-oxygen-enhanced biological wastewater before simultaneous denitrification and targeted phosphorus removal, and then subjected to electrochemical enhanced reaction treatment again to achieve circulation and reflux, resulting in circulated enhanced purified wastewater. For the wastewater from the enhanced purification process, a recirculation and reflux treatment is carried out to obtain deeply purified and reused wastewater.

6. The method for purifying aquaculture wastewater based on moving bed biofilm and electro-oxygen synergy as described in claim 5, characterized in that, The process of circulating and enhancing the purification of wastewater to obtain deeply purified and reused wastewater involves the following steps: During the recirculation process, the recirculation ratio under different combinations of ammonia nitrogen, nitrate nitrogen, total phosphorus and dissolved oxygen concentrations is retrieved through the tailwater control system combined with historical data network. The recirculation ratio is the ratio of the electro-oxygen-enhanced biological tailwater before and after the simultaneous denitrification and targeted phosphorus removal treatment. The recirculation ratio is adjusted in real time, and during the adjustment process, the circulating enhanced purification effluent is subjected to deep oxidation and decomposition through a low-voltage DC electrolysis electrode pair. The online monitoring sensor group of the tailwater control system monitors the concentrations of ammonia nitrogen, nitrate nitrogen, total phosphorus and dissolved oxygen in the circulating enhanced purification tailwater in real time. When the preset purification standard is reached, the circulating enhanced purification tailwater is marked as deep purification and reuse tailwater.

7. The method for purifying aquaculture wastewater based on moving bed biofilm and electro-oxygen synergy as described in claim 1, characterized in that, The process of performing end-of-pipe solid-liquid separation and resource recovery on the deep-purified and reused effluent to complete the effluent purification is as follows: A fine separation zone is set up within the moving bed biofilm reactor; Through the fine separation zone, the deep-purified reuse effluent undergoes end-of-pipe solid-liquid separation treatment. The end-of-pipe solid-liquid separation treatment involves using microporous filter media to create a biofilm and intercept solids in the deep-purified reuse effluent, resulting in solid-liquid separated effluent and solid-liquid separated residue. The solid-liquid separation residue is treated to render it harmless, and the solid-liquid separation tailwater is discharged externally to complete the tailwater purification treatment.

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