A device and method for expanding the population of functional bacteria in a clear water biological method

Abstract

The present application belongs to the field of sewage treatment and microbial culture technology, and discloses a kind of clear water biological method functional bacteria pool in-batch propagation device and method, device includes aerobic tank, anoxic tank, tubular aerator, air blower, bacteria liquid dosing metering pump and reaction liquid backflow pump;Method includes: the high concentration functional bacteria bacteria liquid of pool outside expansion culture is added to pool, and during propagation, based on the strain type of the functional bacteria bacteria liquid to be propagated, set up different culture conditions, and monitor the nutrient consumption amount every day and replenish to standard amount during propagation process, after propagation ends, combine "scene-color-evaluation-verification" to determine whether propagation is successful.The present application realizes the rapid propagation of functional bacteria in the pool through high-concentration targeted start, differential metabolic regulation and molecular-level quantitative evaluation based on functional gene quantification and 16S.

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment and microbial culture technology, specifically to a device and method for propagating functional bacteria in a clear water biological method. Background Technology

[0002] Urban wastewater treatment plants currently widely use the activated sludge process, whose core logic is to degrade pollutants by maintaining a high concentration of mixed microbial communities (sludge concentration is generally 3000 to 5000 mg / L). However, activated sludge itself is a complex system containing hundreds of microorganisms, of which the key bacteria that actually perform nitrification and denitrification functions account for a small proportion. The remaining large number of ineffective bacteria continuously consume carbon sources and dissolved oxygen, resulting in high sludge production, high energy consumption, and poor effluent stability.

[0003] The core logic of the clear water biological process is to replace traditional activated sludge with targeted functional bacteria (mainly including autotrophic nitrifying bacteria and heterotrophic simultaneous nitrification and denitrification bacteria) to achieve efficient nitrogen removal at low sludge concentrations. In-tank propagation technology is a key step in achieving this goal, requiring high-density in-situ proliferation of functional bacteria within the wastewater treatment biological tank without relying on repeated external additions. However, existing in-tank propagation technologies largely borrow from the acclimation model of traditional activated sludge, which has the following drawbacks:

[0004] First, there is a lack of initiation strategies for high-concentration targeted functional bacteria, relying instead on long-term domestication of a small number of functional bacteria in the system, resulting in a long initiation cycle. Second, there is a lack of precise quantitative detection methods for functional bacteria, detecting the "soil" rather than the "functional bacteria". Third, there is a lack of the ability to maintain refined culture conditions that target the metabolic characteristics of functional bacteria, and there is no differentiation and regulation for the different needs of autotrophic and heterotrophic bacteria. Summary of the Invention

[0005] This invention aims to provide a device and method for the propagation of functional bacteria in a clean water biological pond. Through high-concentration targeted initiation, differentiated metabolic regulation, and molecular-level quantitative evaluation based on functional genes and 16S molecules, it achieves rapid propagation of functional bacteria within the pond. This solves the problems in the prior art.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] A biomass propagation device for functional bacteria in a clear water biological method includes an aerobic tank and an anoxic tank. The bottom of the aerobic tank is uniformly equipped with tubular aerators connected to blowers. The top of the aerobic tank has a nutrient inlet and a sampling port. A metering pump for quantitatively adding bacterial solution is located on one side of the aerobic tank. A reaction solution reflux pump for water recirculation is located between the aerobic tank and the anoxic tank. The anoxic tank has an inlet valve and a reflux valve between it and the aerobic tank. The aerobic tank has an outlet valve. Both the aerobic and anoxic tanks contain a carrier.

[0008] Furthermore, the aerobic tank and the anoxic tank are either an integral or separate structure, and the two are connected by the reaction liquid return pump and pipeline to achieve water circulation.

[0009] A method for propagating functional bacteria in a water-based biological process, utilizing the aforementioned device for propagating functional bacteria in a water-based biological process, includes the following steps:

[0010] The wastewater to be treated is first filtered to remove impurities before being injected into the aerobic tank and the anoxic tank. The outlet valve of the aerobic tank and the inlet valve of the anoxic tank are then closed to form a closed culture system during the propagation process.

[0011] Prepare a functional bacterial solution for propagation in the aerobic tank. The functional bacterial solution is composed of autotrophic and heterotrophic bacteria. The functional bacterial solution is injected into the aerobic tank in batches using a metering pump. The total amount of functional bacterial solution is 0.5% to 2.0% of the total water volume in the propagation device.

[0012] Differentiated culture conditions were set based on the strains of the functional bacteria to be propagated. First, autotrophic bacteria were propagated by adding inorganic carbon source and ammonia nitrogen from the nutrient feeding port and controlling the reflux in the aerobic tank. Then, heterotrophic bacteria were propagated by adding organic carbon source, ammonia nitrogen, and nitrate nitrogen and controlling the reflux between the aerobic and anoxic tanks.

[0013] During the process of propagating functional bacteria in the pool, the daily consumption of nutrients and the accumulation of intermediate nitrogen metabolism products in the pool are monitored. When the nutrient consumption is lower than the preset standard amount, it is replenished to the standard amount.

[0014] If there is a need to adjust the propagation indicators or if there are unstable compliance scenarios under continuous influent and effluent operation, continue to inject functional bacterial solution into the tank and repeat the above steps until the effluent reaches the predetermined compliance standard and there is no sludge in the mixed liquor in the tank. At the same time, correct and improve the control indicators.

[0015] Furthermore, the functional bacterial solution is produced by a dedicated external expansion culture device and is a high-concentration functional bacterial solution;

[0016] For autotrophic bacteria: the required concentration is 1×10⁻⁶. 6 ~1×10 7 cells / g (MLSS); Performance requirements: Daily ammonia nitrogen degradation reaches 30~40 mg / L;

[0017] For heterotrophic bacteria: Concentration requirement: 1×10⁻⁶ 8 ~1×10 9 cells / g (MLSS); Performance requirements: Daily COD degradation of 4000~6000 mg / L, and degradation of ammonia nitrogen and total nitrogen of 90~110 mg / L each.

[0018] Furthermore, during the propagation of functional bacteria in the inoculum, a blower is used for aeration, and a tubular aerator provides dissolved oxygen to 2-4 mg / L; the pH is the actual pH of the wastewater, and the temperature is room temperature (15-30℃).

[0019] Furthermore, when propagating autotrophic bacteria, the water in the aerobic tank is self-circulated by turning on the reaction solution return pump; when propagating heterotrophic bacteria, the water in the aerobic tank and the anoxic tank are alternately circulated by turning on the reaction solution return pump and the return valve.

[0020] Furthermore, during the propagation of autotrophic bacteria, ammonia nitrogen is supplemented to 90-110 mg / L and phosphate to 5-10 mg / L through the nutrient feeding port, and NaCl, CaCO3, MgSO4 and trace elements are added; when the ammonia nitrogen concentration is lower than 10 mg / L, it is supplemented to 90-110 mg / L and culture is continued, with ammonia nitrogen supplemented 2-3 times; the inorganic carbon source supplemented daily is NaHCO3, maintaining the total alkalinity of the reaction solution at 200-300 mg / L.

[0021] Furthermore, during the propagation of heterotrophic bacteria, organic carbon sources are added through the nutrient feeding port to achieve a COD of 4000-6000 mg / L, an initial ammonia nitrogen concentration of 30-60 mg / L, an initial nitrate nitrogen concentration of 120-160 mg / L, and an initial phosphate concentration of 10-20 mg / L. NaCl, CaCO3, MgSO4, and trace elements are also added. When the remaining amounts of COD, ammonia nitrogen, and nitrate nitrogen are less than 30% of the standard amount, they are replenished to the standard amount.

[0022] Furthermore, the concentration of functional bacteria in the pool was detected using functional gene quantification and 16S technology, with the characteristic gene sequences of the functional bacteria as targets; wherein, the detection targets for the autotrophic bacteria were the amoA, nxrA, and nxrB functional genes, and the detection targets for the heterotrophic bacteria were the nirS and nirK functional genes.

[0023] Furthermore, after propagation, the method for determining whether the functional bacteria have successfully propagated in the pool includes the following steps:

[0024] S1. Color Observation

[0025] The color of the bacterial solution is used to make a preliminary judgment on whether the functional bacteria have been successfully propagated. Specifically, the color of the qualified bacterial solution after propagation of autotrophic bacteria is transparent off-white to light yellow, while the color of the qualified bacterial solution after propagation of heterotrophic bacteria is translucent off-white to light yellow.

[0026] S2, Pool Concentration and Performance Evaluation

[0027] Based on the activity standards of functional bacteria and the absence of sludge in the mixed liquor within the tank, the success of functional bacteria propagation was determined. The activity standards for autotrophic bacteria were: daily ammonia nitrogen degradation of 35-50 mg / L; and for heterotrophic bacteria, daily COD degradation of 3000-5000 mg / L, and ammonia nitrogen and total nitrogen degradation of 90-150 mg / L. Under continuous influent and effluent operation meeting the standards, the total concentration of functional bacteria was measured under a microscope, and the total concentration of functional bacteria was >10. 7 The cell / g (MLSS) indicates successful propagation of the functional bacteria in the culture tank;

[0028] S3, Verification

[0029] Under the condition of continuous influent and effluent operation meeting the standards, the absolute concentration and community abundance of functional bacteria in the suspended and attached states of the propagation liquid in the pool were detected by functional gene quantification and 16S technology, which verified the successful propagation of functional bacteria.

[0030] The beneficial effects of the technical solution are:

[0031] 1. This invention provides a device and method for propagating functional bacteria in a clear water biological culture pond. It establishes a "separate bacterial species, independent adjustment" propagation system (first propagating autotrophic bacteria, then heterotrophic bacteria, allowing autotrophic bacteria with longer generation cycles to establish dominance and occupy ecological sites; autotrophic bacteria propagation utilizes the self-circulation of water within the aerobic pond, while heterotrophic bacteria propagation utilizes alternating water circulation between the aerobic and anoxic ponds). This solves the problem of mismatched metabolic characteristics among different bacterial species in traditional mixed culture ponds, improving the self-sustaining amplification efficiency of functional bacteria within the pond.

[0032] 2. This invention provides a device and method for the propagation of functional bacteria in a biological purification pond. It constructs a comprehensive quantitative evaluation system encompassing four stages: "scene—color—evaluation—verification." The "scene" is designed based on the characteristics of the influent and effluent; "color" refers to the on-site identification of water color characteristics; "evaluation" involves on-site measurement of the total number of functional bacteria; and "verification" involves sending samples to test the copy number of functional genes and the abundance of microorganisms. This comprehensive quantitative control determines whether the propagation of functional bacteria in the pond is successful. Furthermore, based on functional gene quantification and 16S technology, the absolute copy number of functional genes and the abundance of functional bacteria within the total bacterial community under effluent quality standards are used as quantitative control indicators to verify the successful propagation of functional bacteria in the pond. Targeting specific functional genes of denitrifying bacteria (autotrophic bacteria primarily verify nitrification function: amoA, nxrA, and nxrB; heterotrophic bacteria primarily verify denitrification function: nirS and nirK), this method abandons the traditional crude judgment method of detecting "mud" rather than "functional bacteria." This ensures that the functional bacteria establish an absolute ecological advantage in the pool and that the mixed liquor in the pool is free of sludge, laying the foundation for the long-term operation of the "clear water biological method".

[0033] 3. The present invention provides a device and method for propagating functional bacteria in a clear water biological method pond. By using a high-concentration targeted start-up in the pond (adding external culture liquid at a standard of 0.5%~2.0%), highly active functional bacteria are directly introduced, replacing the traditional inefficient acclimatization mode. This breaks the dependence on the mixed bacterial community of activated sludge, which can significantly shorten the propagation cycle and enable the system to quickly achieve stable biochemical treatment capacity.

[0034] 4. The present invention provides a device and method for propagating functional bacteria in a clean water biological treatment tank. The process is highly adaptable, can be implemented by modifying existing aerobic and anoxic tanks in wastewater treatment plants, and has a simple structure. The parameters of the entire propagation process are clearly defined, making it suitable for urban wastewater treatment plants of different treatment scales and water qualities. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of the structure of a biological functional bacteria propagation device in a clear water pond according to the present invention.

[0036] Figure 2 The above are renderings of a propagation device for a functional bacterial culture pond constructed using a clear water biological method, as shown in embodiments 3 and 4 of this invention.

[0037] Figure 3 This is a diagram illustrating the effect of the complete propagation of autotrophic bacteria in the pool in Embodiment 3 of the present invention.

[0038] Figure 4 This is a diagram showing the effect of the mixed liquor suspended solids (MLSS) concentration in the pool under the condition that the ammonia nitrogen in the effluent meets the standard in Example 3 of the present invention.

[0039] Figure 5This is a diagram illustrating the effect of heterotrophic bacteria propagation in the pool in Embodiment 4 of the present invention.

[0040] Figure 6 This is a diagram showing the effect of MLSS in the pool under the condition that the effluent COD, total nitrogen, and ammonia nitrogen meet the standards in Example 4 of the present invention.

[0041] The names of the corresponding labels in the attached diagram are:

[0042] 1. Aerobic tank body; 2. Anoxic tank body; 3. Anoxic tank inlet valve; 4. Aerobic tank outlet valve; 5. Bacterial liquid dosing metering pump; 6. Blower; 7. Tubular aerator; 8. Sampling port; 9. Reaction liquid return pump; 10. Anoxic tank internal return valve; 11. Nutrient feeding port; 12. Carrier. Detailed Implementation

[0043] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments:

[0044] Example 1: As Figure 1 As shown, a biological functional bacterial propagation device for clear water includes an aerobic tank 1 and an anoxic tank 2. The bottom of the aerobic tank 1 is evenly equipped with tubular aerators 7, which are connected to blowers 6. The top of the aerobic tank 1 has a nutrient inlet 11 and a sampling port 8. A bacterial liquid metering pump 5 for quantitatively adding bacterial liquid is located on one side of the aerobic tank 1. A reaction liquid reflux pump 9 for achieving water reflux is located between the aerobic tank 1 and the anoxic tank 2. The anoxic tank 2 has an anoxic tank inlet valve 3 and a reflux valve 10 between the aerobic tank 1 and the aerobic tank 1. The aerobic tank 1 has an aerobic tank outlet valve 4. A carrier 12 is located inside both the aerobic tank 1 and the anoxic tank.

[0045] In this embodiment, the aerobic tank 1 and the anoxic tank 2 are an integral structure, and the two are connected by a reaction liquid return pump 9 and a pipeline to achieve water circulation; the return valve 10 is set on the return pipeline between the aerobic tank 1 and the anoxic tank 2 to realize the alternating circulation of water between the aerobic tank 1 and the anoxic tank 2.

[0046] Example 2: A method for in-pond propagation of functional bacteria using a clear water biological method, comprising the following steps: The method utilizes the in-pond propagation device for functional bacteria using a clear water biological method as described in Example 1.

[0047] The wastewater to be treated is first filtered to remove impurities and then injected into the aerobic tank 1 and the anoxic tank 2. The outlet valve 4 of the aerobic tank and the inlet valve 3 of the anoxic tank are closed so that the propagation device forms a closed culture system during the propagation period.

[0048] Prepare the functional bacterial solution for propagation in the tank. The functional bacterial solution consists of autotrophic and heterotrophic bacteria. The bacterial solution is injected into the aerobic tank 1 in batches using metering pump 5. The total amount of functional bacterial solution is 0.5% to 2.0% of the total water volume in the propagation device.

[0049] The functional bacteria solution is produced by a dedicated external expansion culture device and is a high-concentration functional bacteria solution; for autotrophic bacteria: the concentration requirement is 1×10⁻⁶. 6 ~1×10 7 cells / g (MLSS); Performance requirements: Daily ammonia nitrogen degradation reaches 30~40 mg / L; For heterotrophic bacteria: Concentration requirement: 1×10⁻⁶ ... 8 ~1×10 9 cells / g (MLSS); Performance requirements: Daily COD degradation of 4000~6000 mg / L, and degradation of ammonia nitrogen and total nitrogen of 90~110 mg / L each;

[0050] During the propagation of functional bacteria in the inoculum, the environmental parameters and controls are as follows: pH is the actual pH of the wastewater, aeration is carried out using blower 6, dissolved oxygen is provided to 2~4 mg / L by tubular aerator 7, and the temperature is normal temperature 15~30 ℃.

[0051] Differentiated culture conditions were set based on the strains of the functional bacteria to be propagated in the culture tank. During the propagation of the functional bacteria in the tank, the consumption of nutrients and the accumulation of intermediate nitrogen metabolism products were monitored daily. When the nutrient consumption was lower than the preset standard amount, it was replenished to the standard amount. Specifically:

[0052] First, propagate autotrophic bacteria by supplementing ammonia nitrogen to 90-110 mg / L and phosphate to 5-10 mg / L through nutrient feeding port 11, and add NaCl, CaCO3, MgSO4 and trace elements; when the ammonia nitrogen concentration is lower than 10 mg / L, supplement to 90-110 mg / L and continue cultivation, supplementing ammonia nitrogen 2-3 times; the inorganic carbon source supplemented daily is NaHCO3, maintaining the total alkalinity of the reaction solution at 200-300 mg / L; and the water in the aerobic tank 1 is self-circulated by turning on the reaction solution return pump 9;

[0053] After the heterotrophic bacteria are propagated, organic carbon source is added through nutrient feeding port 11 to make the COD in the tank reach 4000~6000 mg / L, ammonia nitrogen concentration 30~50 mg / L, initial nitrate nitrogen concentration about 140~160 mg / L, initial phosphate concentration 10~20 mg / L, and add NaCl, CaCO3, MgSO4 and trace elements; when the remaining amount of COD, ammonia nitrogen and nitrate nitrogen is less than 30%, it is replenished to the standard amount; and by opening the reaction liquid return pump 9 and the return valve 10 in the anoxic tank, the water body alternately circulates between the aerobic tank 1 and the anoxic tank 2.

[0054] If there is a need to adjust the propagation indicators or if there are unstable compliance scenarios under continuous influent and effluent operation, continue to inject functional bacterial solution into the tank and repeat the above steps until the effluent reaches the predetermined compliance standard and there is no sludge in the mixed liquor in the tank. At the same time, correct and improve the control indicators.

[0055] The method employed functional gene quantification and 16S technology to detect the number of functional bacteria in the pool, using the characteristic gene sequences of functional bacteria as targets. The detection targets for autotrophic bacteria were the amoA, nxrA, and nxrB functional genes, while the detection targets for heterotrophic bacteria were the nirS and nirK functional genes.

[0056] The method for determining whether functional bacteria have successfully proliferated in the pool includes the following steps:

[0057] S1. Color Observation

[0058] The color of the bacterial solution is used to make a preliminary judgment on whether the functional bacteria have been successfully propagated. Specifically, the color of the qualified bacterial solution after propagation of autotrophic bacteria is transparent off-white to light yellow, while the color of the qualified bacterial solution after propagation of heterotrophic bacteria is translucent off-white to light yellow.

[0059] S2, Pool Concentration and Performance Evaluation

[0060] Based on the activity standards of functional bacteria and the absence of sludge in the mixed liquor within the tank, the success of functional bacteria propagation was determined. The activity standards for autotrophic bacteria were: daily ammonia nitrogen degradation of 35-50 mg / L; and for heterotrophic bacteria, daily COD degradation of 3000-5000 mg / L, and ammonia nitrogen and total nitrogen degradation of 90-150 mg / L. Under continuous influent and effluent operation meeting the standards, the total concentration of functional bacteria was measured under a microscope, and the total concentration of functional bacteria was >10. 7 The cell / g (MLSS) indicates that the functional bacteria have been successfully propagated in the pool.

[0061] S3, Verification

[0062] Under the condition of continuous influent and effluent operation meeting the standards, the absolute concentration and community abundance of functional bacteria in the suspended and attached states of the propagation liquid in the pool were detected by functional gene quantification and 16S technology, which verified the successful propagation of functional bacteria.

[0063] Example 3: Propagation of autotrophic bacteria in a pond

[0064] like Figure 2 As shown, a 75 m³ / d process device with a "filtration-anaerobic-anoxic-aerobic" structure was constructed. The hydraulic retention times of the anoxic tank (tank 2) and the aerobic tank (tank 1) were 6 h and 8 h, respectively. The aerobic tank (tank 1) served as the propagation container, with an effective volume of 27 m³, and contained a root membrane carrier. The actual wastewater to be treated was first filtered to remove impurities before being injected into the tank. The aerobic tank outlet valve 4 and the anoxic tank inlet valve 3 were then closed, creating a closed cultivation system during propagation. Approximately 220 L of autotrophic bacterial solution (approximately 0.8% of the total 27 m³ volume of the aerobic tank) was added to the aerobic tank (tank 1) using a metering pump 5. The bacterial solution was produced by a dedicated external propagation device based on autotrophic seed culture and was a high-concentration functional bacterial solution; the concentration requirement was 1×10⁻⁶. 6 ~1×10 7 cells / g (MLSS); Performance requirements: Daily ammonia nitrogen degradation reaches 30~40 mg / L.

[0065] Initial nutrient supplementation: Add an appropriate amount of (NH4)2SO4 to supplement ammonia nitrogen to approximately 100 mg / L, add KH2PO4 to supplement phosphate to 5-10 mg / L, and appropriate amounts of NaCl, CaCO3, MgSO4, and trace elements; add NaHCO3 daily as an inorganic carbon source and supplement total alkalinity to 200-300 mg / L. Turn on the reaction liquid reflux pump 9 to achieve water circulation in the aerobic tank 1. The pH is the actual wastewater pH, dissolved oxygen is 2-4 mg / L, and the temperature is ambient (15-30℃).

[0066] Testing showed that by day 10, the ammonia nitrogen removal rate reached 39.05 mg / (L·d), and by day 11, the ammonia nitrogen level was 0 mg / L. On-site observation in the pool revealed that the autotrophic bacteria culture solution was a transparent, off-white color. Figure 3 As shown.

[0067] After the autotrophic bacteria in the pool of this embodiment have multiplied and the heterotrophic bacteria in the pool of Example 4 have multiplied, the continuous influent and effluent mode is started. After 1 to 2 weeks of debugging, the effluent water quality can stably meet the Class A (daily average) of the "Discharge Standard of Pollutants for Municipal Wastewater Treatment Plants" (GB 18918-2002) with ammonia nitrogen ≤5 mg / L. When the effluent water quality is better, under the condition that the influent ammonia nitrogen concentration is 30 to 40 mg / L, the effluent ammonia nitrogen concentration can be reduced to 1.0 to 1.5 mg / L in a few days, meeting the Class IV water quality standard of the "Surface Water Environmental Quality Standard" (GB 3838-2002) with ammonia nitrogen concentration ≤1.5 mg / L.

[0068] Under conditions where the effluent meets standards, after the sludge volume in the tank is reduced by more than 90%, the total concentration of functional bacteria is >10 when measured under a microscope. 7 The sample was sent for functional gene quantification and 16S assay, with a cell / g count. The copy number of functional genes amoA, nxrA, and nxrB in the mixed suspension was >10. 5 The abundance of nitrifying bacteria is >15%; the copy number of the functional genes amoA, nxrA, and nxrB attached to the biofilm on the aerobic tank carrier is >10 copies / g. 6 The abundance of nitrifying bacteria is >30% (copies / g). Furthermore, under compliant conditions, the mixed liquor suspended solids (MLSS) concentration in the tank is 82±19 mg / L. Figure 4 As shown, the mixed liquor sludge concentration (MLSS) of the activated sludge process is generally between 3000 and 5000 mg / L. The successful propagation of autotrophic bacteria in the tank was comprehensively determined and verified.

[0069] Example 4: Propagation of heterotrophic bacteria in a pond

[0070] like Figure 2 As shown, a device with a design capacity of 75 m³ / d and a process of "filtration-anaerobic-anoxic-aerobic" was constructed. The hydraulic retention times of the anoxic tank 2 and the aerobic tank 1 were 6 h and 8 h, respectively. The aerobic tank 1 with an effective volume of 27 m³ and the anoxic tank 2 with an effective volume of 20 m³ were used as in-tank propagation containers, with root membrane carriers installed inside. Based on the successful propagation of autotrophic bacteria in Example 3, approximately 220 L of externally propagated heterotrophic bacterial solution (approximately 0.5% of the total water volume) was added to the aerobic tank 1 by metering pump 5. The bacterial solution was produced by a dedicated external propagation device based on heterotrophic bacterial seed liquid and was a high-concentration functional bacterial solution; the concentration requirement was 1×10⁻⁶. 8 ~1×10 9 cells / g (MLSS); Performance requirements: Daily COD degradation of 4000~6000 mg / L, and degradation of ammonia nitrogen and total nitrogen of 90~110 mg / L each;

[0071] Initial nutrient supplementation: Add glucose to achieve a COD of 4000-6000 mg / L, add (NH4)2SO4 to supplement ammonia nitrogen (approximately 50 mg / L), add KNO3 to supplement nitrate nitrogen (approximately 150 mg / L), add KH2PO4 to supplement phosphate (10-20 mg / L), and add appropriate amounts of NaCl, CaCO3, MgSO4, and trace elements. Turn on the reaction liquid reflux pump 9 and the reflux valve 10 in the anoxic tank to achieve water circulation between the aerobic tank 1 and the anoxic tank 2. The pH is the actual wastewater pH, dissolved oxygen is 2-4 mg / L, and the temperature is ambient (15-30℃).

[0072] Daily testing of COD, ammonia nitrogen, nitrite nitrogen, and nitrate nitrogen levels is conducted. When nutrient levels fall below 30%, the corresponding substrate is added to bring the levels back to the standard.

[0073] Testing showed that by day 5 of propagation, the ammonia nitrogen removal rate reached 31 mg / (L·d), the nitrate nitrogen removal rate reached 67 mg / (L·d), and the COD removal rate reached 3200 mg / (L·d). The remaining ammonia nitrogen concentration was 13.88 mg / L, the nitrate nitrogen concentration was 0 mg / L, and the COD concentration was 0 mg / L. On-site observation of the heterotrophic bacteria propagating in the tank revealed a translucent, off-white color. Figure 5 As shown.

[0074] After the heterotrophic bacteria in the pool in this embodiment have propagated, the continuous influent / effluent mode is started. After 1-2 weeks of debugging, under the condition that the influent COD concentration is mainly 150-250 mg / L, the effluent COD concentration is stabilized at 15-30 mg / L, which can stably meet the COD concentration ≤30 mg / L of Class IV water quality standard of the "Surface Water Environmental Quality Standard" (GB 3838-2002). Under the condition that the influent total nitrogen concentration is 30-40 mg / L, the effluent total nitrogen concentration is stabilized at 13-20 mg / L, which can stably meet the total nitrogen ≤20 mg / L of Class A (instantaneous value) of the "Discharge Standard of Pollutants for Municipal Wastewater Treatment Plants" (GB 18918-2002) Amendment; the effluent ammonia nitrogen concentration is stabilized at 1.0-5.0 mg / L, which can stably meet the ammonia nitrogen ≤5 mg / L of Class A (daily average value) of the "Discharge Standard of Pollutants for Municipal Wastewater Treatment Plants" (GB18918-2002).

[0075] Under effluent quality standards, the total concentration of functional bacteria detected by microscopy is >10. 7 The sample was sent for functional gene quantification and 16S detection, and the copy number of functional genes nirS and nirK in the reaction solution suspension was >10. 7The abundance of bacterial communities with simultaneous nitrification and denitrification functions is >40%; the copy number of attached functional genes nirS and nirK on the biofilm of the anoxic pond carrier is >10 copies / g. 8 The abundance of bacteria with simultaneous nitrification and denitrification functions is >60%, and the abundance of bacteria with simultaneous nitrification and denitrification functions attached to the biofilm on the aerobic tank carrier is >40%. Furthermore, under compliant conditions, the MLSS in the tank is 59±13 mg / L. Figure 6 As shown, the MLSS in the activated sludge process is generally between 3000 and 5000 mg / L. The successful propagation of heterotrophic bacteria in the tank was comprehensively determined and verified.

[0076] In summary, this invention relies on an in-tank propagation mode, introducing highly active functional bacteria solution at a standard ratio of approximately 1%. This allows for rapid propagation of the in-tank bacterial community, quickly making the functional bacteria the dominant group. It activates and proliferates the functional bacteria within the tank, increasing the initial concentration. This effectively solves the problem of functional bacteria obtained from off-site cultivation becoming dominant bacteria in a new wastewater treatment system through in-tank propagation, eliminating dependence on the original mixed sludge bacteria community within the tank. It enables the functional bacteria to operate sustainably in the biological treatment tank for a long period, successfully establishing a complete chain for the clear water biological treatment process: "addition of functional bacteria solution based on off-site cultivation of targeted source bacteria, in-tank propagation of functional bacteria, and operation meeting standards." This provides core operational assurance for wastewater treatment plants to replace traditional activated sludge with functional bacteria in the long term.

[0077] This invention constructs a full-process quantitative evaluation system consisting of four stages: "scene-color-evaluation-verification". The "scene" is designed based on the characteristics of influent and effluent; "color" is used to identify water color characteristics on-site; "evaluation" is used to measure the number of microorganisms on-site; and "verification" is used to test the copy number of functional genes and the abundance of microorganisms in samples. Through full-process quantitative control, the success of functional bacterial proliferation in the pool is determined. Using functional gene quantification and 16S detection technology, characteristic functional genes such as amoA, nxrA, nxrB, nirS, and nirK are targeted for detection. The absolute number and community proportion of functional bacteria under the standard state are accurately verified, upgrading the bacterial community evaluation from the traditional "overall appearance estimation" to precise detection at the molecular level.

[0078] The functional bacterial flora propagated using this invention exhibits high activity and can efficiently remove pollutants such as COD, ammonia nitrogen, and total nitrogen from water bodies. Simultaneously, it reduces carbon emissions from the source, particularly in areas like bacterial metabolism and sludge transfer and disposal, achieving energy conservation and emission reduction throughout the process. This aligns with the national "dual-carbon" development strategy and ecological environmental protection requirements, demonstrating significant social and environmental benefits. Furthermore, this invention can be implemented by modifying existing aerobic and anoxic tanks in wastewater treatment plants. The supporting equipment has a simple structure and low modification difficulty, making it adaptable to urban wastewater treatment plants of varying treatment scales and influent water qualities. The entire propagation process parameters are clearly defined, and once the functional bacteria establish dominance, it can operate sustainably for a long period. This results in low maintenance difficulty and strong system stability, making it suitable for both new wastewater treatment projects and upgrading traditional activated sludge wastewater treatment plants. The technology is highly versatile and easily implemented in engineering projects.

[0079] The above descriptions are merely embodiments of the present invention, and common knowledge regarding specific technical solutions or characteristics is not elaborated upon here. It should be noted that those skilled in the art can make various modifications and improvements without departing from the technical solutions of the present invention, and these should also be considered within the scope of protection of the present invention. These modifications and improvements will not affect the effectiveness of the implementation of the present invention or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A device for propagating functional bacteria in a clear water biological method functional bacteria pond, characterized in that, The system includes an aerobic tank and an anoxic tank. The bottom of the aerobic tank is evenly equipped with tubular aerators connected to blowers. The top of the aerobic tank has a nutrient inlet and a sampling port. A metering pump for quantitatively adding bacterial solution is located on one side of the aerobic tank. A reaction solution reflux pump for water recirculation is located between the aerobic tank and the anoxic tank. The anoxic tank has an inlet valve and a reflux valve between it and the aerobic tank. The aerobic tank has an outlet valve. Both the aerobic and anoxic tanks contain a carrier.

2. The device for propagating functional bacteria in a clear water biological method in a pond according to claim 1, characterized in that, The aerobic tank and the anoxic tank are either an integral or separate structure, and the two are connected by the reaction liquid return pump and pipeline to achieve water circulation.

3. A method for propagating functional bacteria in a water-based biological process in a pond, comprising using a water-based biological process functional bacteria propagation device as described in any one of claims 1-2 to propagate functional bacteria in the pond, characterized in that, Includes the following steps: The wastewater to be treated is first filtered to remove impurities before being injected into the aerobic tank and the anoxic tank. The outlet valve of the aerobic tank and the inlet valve of the anoxic tank are then closed to form a closed culture system during the propagation process. Prepare a functional bacterial solution for propagation in the aerobic tank. The functional bacterial solution is composed of autotrophic and heterotrophic bacteria. The functional bacterial solution is injected into the aerobic tank in batches using a metering pump. The total amount of functional bacterial solution is 0.5% to 2.0% of the total water volume in the propagation device. Differentiated culture conditions were set based on the strains of the functional bacteria to be propagated. First, autotrophic bacteria were propagated by adding inorganic carbon source and ammonia nitrogen from the nutrient feeding port and controlling the reflux in the aerobic tank. Then, heterotrophic bacteria were propagated by adding organic carbon source, ammonia nitrogen, and nitrate nitrogen and controlling the reflux between the aerobic and anoxic tanks. During the process of propagating functional bacteria in the pool, the daily consumption of nutrients and the accumulation of intermediate nitrogen metabolism products in the pool are monitored. When the nutrient consumption is lower than the preset standard amount, it is replenished to the standard amount. If there is a need to adjust the propagation indicators or if there are unstable compliance scenarios under continuous influent and effluent operation, continue to inject functional bacterial solution into the tank and repeat the above steps until the effluent reaches the predetermined compliance standard and there is no sludge in the mixed liquor in the tank.

4. The method for propagating functional bacteria in a clear water biological pond according to claim 3, characterized in that, The functional bacterial solution is produced by a dedicated external expansion and cultivation device and is a high-concentration functional bacterial solution. For autotrophic bacteria: the required concentration is 1×10⁻⁶. 6 ~1×10 7 cells / g (MLSS); Performance requirements: Daily ammonia nitrogen degradation reaches 30~40 mg / L; For heterotrophic bacteria: Concentration requirement: 1×10⁻⁶ 8 ~1×10 9 cells / g (MLSS); Performance requirements: Daily COD degradation of 4000~6000 mg / L, and degradation of ammonia nitrogen and total nitrogen of 90~110 mg / L each.

5. The method for propagating functional bacteria in a clear water biological pond according to claim 3, characterized in that, During the propagation of functional bacteria in the culture, a blower is used for aeration, and a tubular aerator provides dissolved oxygen to 2-4 mg / L.

6. The method for propagating functional bacteria in a clear water biological pond according to claim 3, characterized in that, When propagating autotrophic bacteria, the water in the aerobic tank is self-circulated by turning on the reaction liquid return pump; when propagating heterotrophic bacteria, the water in the aerobic tank and the anoxic tank are alternately circulated by turning on the reaction liquid return pump and the return valve.

7. The method for propagating functional bacteria in a clear water biological pond according to claim 6, characterized in that, When propagating autotrophic bacteria, supplement ammonia nitrogen to 90-110 mg / L and phosphate to 5-10 mg / L through the nutrient feeding port, and add NaCl, CaCO3, MgSO4 and trace elements; when the ammonia nitrogen concentration is lower than 10 mg / L, supplement to 90-110 mg / L and continue culturing, supplementing ammonia nitrogen 2-3 times; the inorganic carbon source supplemented daily is NaHCO3, maintaining the total alkalinity of the reaction solution at 200-300 mg / L.

8. The method for propagating functional bacteria in a clear water biological pond according to claim 6, characterized in that, When propagating heterotrophic bacteria, add organic carbon source through the nutrient feeding port to make the COD in the tank reach 4000~6000 mg / L, the initial ammonia nitrogen concentration 30~60 mg / L, the initial nitrate nitrogen concentration 120~160 mg / L, and the initial phosphate concentration 10~20 mg / L. Add NaCl, CaCO3, MgSO4 and trace elements. When the remaining amount of COD, ammonia nitrogen and nitrate nitrogen is less than 30% of the standard amount, replenish to the standard amount.

9. The method for propagating functional bacteria in a clear water biological method functional bacteria pond according to claim 3, characterized in that, The concentration of functional bacteria in the pool was detected using functional gene quantification and 16S technology, with the characteristic gene sequences of the functional bacteria as targets; wherein, the detection targets for the autotrophic bacteria were the amoA, nxrA and nxrB functional genes, and the detection targets for the heterotrophic bacteria were the nirS and nirK functional genes.

10. The method for propagating functional bacteria in a clear water biological pond according to claim 3, characterized in that, After propagation, the method for determining whether the functional bacteria have successfully propagated in the pool includes the following steps: S1. Color Observation The color of the bacterial solution is used to make a preliminary judgment on whether the functional bacteria have been successfully propagated. Specifically, the color of the qualified bacterial solution after propagation of autotrophic bacteria is transparent off-white to light yellow, while the color of the qualified bacterial solution after propagation of heterotrophic bacteria is translucent off-white to light yellow. S2, Pool Concentration and Performance Evaluation Based on the activity standards of functional bacteria and the absence of sludge in the mixed liquor within the tank, the success of functional bacteria propagation was determined. The activity standards for autotrophic bacteria were: daily ammonia nitrogen degradation of 35-50 mg / L; and for heterotrophic bacteria, daily COD degradation of 3000-5000 mg / L, and ammonia nitrogen and total nitrogen degradation of 90-150 mg / L. Under continuous influent and effluent operation meeting the standards, the total concentration of functional bacteria was measured under a microscope, and the total concentration of functional bacteria was >10. 7 The cell / g (MLSS) indicates successful propagation of the functional bacteria in the culture tank; S3, Verification Under the condition of continuous influent and effluent operation meeting the standards, the absolute concentration and community abundance of functional bacteria in the suspended and attached states of the propagation liquid in the pool were detected by functional gene quantification and 16S technology, which verified the successful propagation of functional bacteria.

11. The method for propagating functional bacteria in a clear water biological method functional bacteria pond according to claim 10, characterized in that, After the functional bacteria in the pool are successfully propagated, the continuous inflow and outflow mode is started. The mixed liquor in the pool is free of sludge, achieving sludge-free operation with functional bacteria having an absolute ecological advantage.

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