SNADF efficient biological denitrification device and method based on endogenous biomass fermentation

Abstract

The invention relates to the technical field of biological denitrification, in particular to an SNADF efficient biological denitrification device and method based on endogenous biomass fermentation. According to the specific technical scheme, the method comprises the following steps: (1) adding sewage and livestock and poultry wastewater into a reactor, starting a short-cut nitrification process, controlling dissolved oxygen to be 0.3-0.5 mg / L, controlling the pH to be 7.5-8.0, and controlling the total nitrogen removal rate of the reactor to be higher than 85%; (2) the C / N ratio is adjusted to 0-0.1, the temperature is adjusted to 20-25 DEG C, the HRT is adjusted to 48-60 h, and the hunger strategy time is 36-48 h; after the hunger strategy, the C / N is recovered to 1-1.5, the temperature is recovered to 30-35 DEG C, the HRT is recovered to 16-20 h, and the recovery period is 48-60 h; during the starvation strategy implementation period, the ammonia nitrogen in the effluent of the reactor is not higher than 50mg / L, the nitrite concentration is not higher than 20mg / L, and the total nitrogen removal rate of the reactor is higher than 93%. According to the method, endogenous biomass such as an extracellular polymeric substance (EPS) is taken as a fermentation substrate, an SNADF process is realized in a reactor, and high-level denitrification, sludge reduction performance and low-energy-consumption operation can be realized at the same time.

Description

Technical Field

[0001] The present invention relates to the technical field of biological denitrification, and particularly relates to a SNADF high-efficiency biological denitrification device and method based on endogenous biomass fermentation. Background Art

[0002] With the rapid development of the livestock and aquaculture industries, livestock and poultry breeding wastewater has become the main non-point source pollution of regional environmental nitrogen pollution. Since breeding wastewater always contains high concentrations of ammonia nitrogen, organic matter and antibiotics, it is crucial to develop an effective and economical advanced treatment technology for breeding wastewater to protect the environment and maintain the sustainable development of the breeding industry.

[0003] In the currently commonly used breeding wastewater treatment processes, the wastewater is usually first anaerobically treated, and the treated wastewater exhibits typical low C / N ratio characteristics. The most commonly used processes include primary sedimentation tanks, anaerobic digestion tanks, conditioning tanks, anaerobic tanks, aerobic aeration tanks, anoxic tanks, sedimentation tanks, etc. However, the traditional biological nitrification and denitrification technology for treating pig farm wastewater has the disadvantages of high equipment investment, high energy consumption, high operating costs and high land requirements.

[0004] Anaerobic ammonium oxidation (Anammox) is an autotrophic microbial process, and the wastewater treatment technology mediated by it is considered an effective, green and economical process due to its characteristics of low sludge production, low energy consumption and low operating costs. Therefore, the Anammox-mediated system is a promising option for low C / N ratio pig farm wastewater, with significant cost-effectiveness, such as the partial nitrification-anammox (PNA) process and the denitrification combined process, or the simultaneous partial nitrification, anammox and denitrification (SNAD) process.

[0005] However, the nitrate produced during the anaerobic ammonium oxidation process limits the theoretical denitrification efficiency of the partial nitrification / anammox (PNA) process to 89%. The simultaneous partial nitrification, anammox and denitrification (SNAD) process that combines PNA with heterotrophic denitrification can further reduce the nitrate concentration in the effluent. The uncertainty of organic matter addition in the SNAD process can cause inhibition of anammox activity and secondary organic pollution of public water bodies, which results in unstable denitrification effects and increased operating costs. Therefore, combining fermentation with anaerobic ammonium oxidation to form the short-term nitrification, anaerobic ammonium oxidation, denitrification and fermentation (SNADF) process provides a new idea for low-energy high-efficiency denitrification. However, the above processes require multiple units to coordinate and cooperate to complete denitrification, increasing the operation complexity. In addition, to maintain the continuous progress of the fermentation process in the denitrification system, it is necessary to continuously supplement exogenous fermentation substrates, which undoubtedly increases the operation difficulty and operating costs. Summary of the Invention

[0006] In view of the deficiencies of the prior art, the present invention provides a high-efficiency biological nitrogen removal device and method based on endogenous biomass fermentation, using extracellular polymeric substances (EPS) and other endogenous biomass as fermentation substrates to implement the SNADF process in a reactor, which can simultaneously achieve high-level nitrogen removal, sludge reduction performance, and low-energy consumption operation.

[0007] To achieve the above objectives, the present invention is realized through the following technical solutions:

[0008] The present invention discloses a high-efficiency biological nitrogen removal method based on endogenous biomass fermentation, comprising the following steps:

[0009] (1) Initiation of the shortcut nitrification / anaerobic ammonium oxidation process

[0010] In the reactor, sewage and livestock wastewater are added. After initiating the shortcut nitrification process, before inoculating Anammox granular sludge, the ammonia nitrogen and nitrite concentrations in the effluent are controlled at 80 - 150 mg / L, with a ratio close to 1:1, the dissolved oxygen is controlled at 0.3 - 0.5 mg / L, the pH is controlled at 7.5 - 8.0, and the total nitrogen removal rate of the reactor is higher than 85%, indicating the successful initiation of the shortcut nitrification / anaerobic ammonium oxidation process;

[0011] (2) Completion of the carbon self-sufficient SNADF process initiation by selectively enriching fermentation bacteria OLB8 and Pedosphaeraceae through the starvation strategy

[0012] The C / N ratio is adjusted to 0 - 0.1, the temperature is adjusted to 20 - 25 °C, the HRT is adjusted to 48 - 60 h, and the starvation strategy time is 36 - 48 h; after the starvation strategy, the C / N is restored to 1 - 1.5, the temperature is restored to 30 - 35 °C, the HRT is restored to 16 - 20 h, and the recovery period is 48 - 60 h; this process selectively eliminates Anaerolineaceae bacteria that use influent organic matter as a metabolic substrate by stopping the supply of carbon sources, and enriches OLB8 bacteria and Pedosphaeraceae bacteria that use endogenous organic matter (such as extracellular polymeric substances and cell lysis products) as a metabolic substrate.

[0013] Subsequently, the starvation strategy is carried out, repeated 3 - 5 times. During this period, the dissolved oxygen is controlled at 0.02 - 0.1 mg / L, the redox potential is controlled at -50 mV - -200 mV. During the implementation of the starvation strategy, the ammonia nitrogen in the reactor effluent shall not be higher than 50 mg / L, the nitrite concentration shall not be higher than 20 mg / L, and the total nitrogen removal rate of the reactor is higher than 93%, indicating the successful initiation of the carbon self-sufficient SNADF process.

[0014] (3) Achieving the stable operation of the denitrification and fermentation processes based on the dissolved oxygen feedback regulation mechanism

[0015] When the dissolved oxygen concentration is between 0.01 and 0.05 mg / L, continuous aeration is adopted; when the dissolved oxygen concentration is between 0.05 and 0.1 mg / L, intermittent aeration is adopted, that is, 5 minutes of aeration + 5 minutes of static settlement; when the dissolved oxygen is higher than 0.1 mg / L, aeration is stopped to achieve the directional enrichment of different functional microorganisms in different types of sludge. During the operation, Candidatus Kuenenia is maintained in the granular sludge with a relative abundance of not less than 20%; OLB8 is enriched in the flocculent sludge with a relative abundance of not less than 5%; SJA-28 is enriched in the biofilm with a relative abundance of not less than 10%.

[0016] Preferably, in step (1), the free ammonia is maintained at 20 - 30 mg / L, the dissolved oxygen is maintained at 1 - 2 mg / L, and the pH is controlled at 6.8 - 8.5, that is, the shortcut nitrification process is successfully started.

[0017] Preferably, the shortcut nitrification process is started by inoculating the return sludge from the secondary sedimentation tank in the reactor, and the initial sludge concentration is 4 - 5 g MLSS / L; during the start-up stage of the shortcut nitrification process, the influent ammonia nitrogen is controlled at 150 - 250 mg / L; after the shortcut nitrification process is successfully started, the sewage influent ratio is reduced by 10% every 5 - 10 days until it reaches zero, and the influent ammonia nitrogen concentration is 800 - 900 mg / L.

[0018] Preferably, in step (1), the concentration of inoculated Anammox granular sludge is 3 - 4 g MLSS / L; after the shortcut nitrification / anaerobic ammonium oxidation process is started, the sewage influent ratio is reduced by 10% every 5 - 15 days until it reaches zero; during the period of reducing the sewage influent ratio, the effluent maintains an ammonia nitrogen concentration of 20 - 50 mg / L and a nitrite concentration of 10 - 30 mg / L; after the reactor treats 100% of the livestock and poultry wastewater, the effluent is controlled to maintain an ammonia nitrogen concentration of 10 - 20 mg / L and a nitrite concentration of 0 - 10 mg / L; during the operation of the shortcut nitrification / anaerobic ammonium oxidation process, the dissolved oxygen is maintained at 0.1 - 0.3 mg / L.

[0019] Preferably, in step (2), during the operation of the carbon self-supplied SNADF process, the C / N is adjusted to 0.1 - 0.3, the temperature is maintained at 32 - 35 °C, the HRT is maintained at 12 - 18 h, the dissolved oxygen is maintained at 0.02 - 0.08 mg / L, and the redox potential is controlled at -0 mV to -200 mV; the effluent maintains an ammonia nitrogen concentration of 0 - 15 mg / L and a nitrite concentration of 0 - 5 mg / L.

[0020] Correspondingly, a device used in the SNADF high-efficiency biological nitrogen removal method based on endogenous biomass fermentation includes a reactor. The reactor is fed with water through a sewage water pump and a livestock and poultry wastewater pump, and the effluent is discharged through a water pump connected to a membrane module. A screw blower equipped with a first air flow meter is connected to a disk aerator, and a biofilm carrier, a liquid level sensor, and a heater are arranged in the reactor.

[0021] Preferably, a gas collection hood is arranged at the top of the reactor, and a membrane scouring module is arranged at the bottom of the membrane module. The membrane scouring module is connected to a circulating blower equipped with a second air flow meter.

[0022] Preferably, a spray defoaming mechanism is arranged above the membrane module in the reactor, and the spray defoaming mechanism is connected to the circulating blower through a third air flow meter.

[0023] Preferably, the biofilm carrier is a hollow carrier ball, and 8-10 polyurethane sponge carriers are installed in the hollow carrier ball.

[0024] The present invention has the following beneficial effects:

[0025] 1. A method for forming and directionally cultivating fermentation bacteria OLB8 and Pedosphaeraceae based on the starvation strategy of carbon source limitation. The present invention can complete the startup of the carbon self-sufficient SNADF denitrification system in 8-14 days. The ability of fermentation microorganisms to degrade complex organic matter is enhanced under starvation conditions. When the easily degradable organic matter in the reactor is exhausted, the hardly degradable organic matter can be utilized as a carbon source by the corresponding degrading bacteria. Therefore, by regulating the carbon source supply, in the starvation environment after stopping the carbon source supply, Anaerolineaceae bacteria that use influent organic matter as a metabolic substrate can be selectively eliminated, reducing the competitive effect of non-target bacteria, and finally enriching OLB8 bacteria and Pedosphaeraceae bacteria that use endogenous organic matter (such as extracellular polymeric substances and cell lysis products) as a metabolic substrate. In addition, since acid-producing bacteria and methanogenic bacteria have great differences in growth, substrate utilization rate, and sensitivity to environmental changes. Compared with acid-producing bacteria, methanogenic bacteria need to experience a longer lag phase after starvation. The imbalance between the production and consumption rates of acidification products usually leads to the accumulation of acid and the loss of methanogenic activity. Therefore, the starvation operation can control the fermentation process in the acid-producing stage, convert endogenous biomass into available carbon sources to support denitrification, and avoid carbon source loss caused by methanogenesis.

[0026] 2. Compared with the traditional nitrification-denitrification process, the carbon self-sufficient SNADF process can reduce the aeration energy consumption by 60%, the carbon source addition by 100%, and the excess sludge treatment cost by 98%, with extremely low operating costs. The operating costs of the traditional nitrification-denitrification process mainly include aeration, external organic matter addition, and excess sludge treatment. Considering that the PN process can save 25% of the oxygen demand, the SNADF process can save 60% of the aeration energy consumption. In the carbon self-sufficient SNADF process, the fermentation process promotes the conversion and utilization of endogenous biomass, thus eliminating the need for external organic matter by 100%. In addition, the carbon self-sufficient SNADF process can reduce the excess sludge production by 90% through fermentation treatment. Considering that the sludge production of the PNA process is only about 15% of that of the traditional biological nitrogen removal process. Therefore, the sludge production of the carbon self-sufficient SNADF process is about 1.5% of that of the traditional process, achieving near-zero discharge of excess sludge. The traditional process removes 1 mg / L NH 4 + -N, consuming 0.890 mg / L COD and 1.12 mg / L O 2 , producing 0.596 mg VSS sludge. The carbon self-sufficient SNADF process removes 1 mg / L NH 4 + -N, only requiring 0.448 mg / L O 2 , producing 0.008 mg VSS sludge.

[0027] 3. The carbon self-sufficient SNADF process has high and stable nitrogen removal efficiency, extremely low excess sludge discharge, and simple operation. Although the PNA process can achieve a relatively high nitrogen removal load at high activity and high MLVSS, the TNRE is limited to 89% due to the problem of nitrate in the effluent. Especially in the treatment of high-nitrogen-concentration wastewater (such as aquaculture wastewater, landfill leachate, etc.), the poor effluent quality caused by nitrate residue is still an obstacle to the engineering application of the anaerobic ammonium oxidation process. The carbon self-sufficient SNADF process uses in-situ fermentation products as a carbon source to support nitrate removal, which can not only improve the TNRE but also reduce the excess sludge production of the nitrogen removal system. Under similar influent loads and ΔCOD / TN conditions, the nitrate in the effluent of the SNADF process is 40 - 50 mg / L lower than that of the PNA process, and the corresponding TNRE is increased by 9.5%. The excess sludge production of the carbon self-sufficient SNADF process is only one-tenth of that of the PNA process. In addition, in the actual operation of the conventional SNAD process, it is necessary to maintain the organic matter concentration within a suitable range in real-time to achieve the balance between AnAOB and denitrifying bacteria. The carbon self-sufficient SNADF process omits the carbon source addition process and avoids the risk of system instability caused by the interspecies competition of functional microorganisms.

[0028] 4. Based on the dissolved oxygen feedback regulation mechanism, the collaborative relationship among functional microorganisms in different forms of sludge (flocs, granules, biofilms) in the carbon self-supplying SNADF process ensures the stable operation of the SNADF process. Different forms of sludge provide different physical and chemical environments for the collaboration between anaerobic ammonium-oxidizing bacteria and other functional microorganisms. Under the forms of flocs, granules and biofilms, the microbial community can carry out effective cooperation and metabolic coupling with the support of spatial and nutritional conditions, promote various reactions in the nitrogen cycle, and improve the removal efficiency of organic matter and nitrogen in the sludge. Implement the automatic dissolved oxygen control strategy, provide dissolved oxygen while amplifying the oxygen transfer differences in different types of sludge, and achieve the directional enrichment of different functional microorganisms in different types of sludge. Ammonia-oxidizing bacteria, anaerobic ammonium-oxidizing bacteria and denitrifying bacteria are enriched in floc sludge, granular sludge and biofilm sludge respectively. Candidatus_Kuenenia (anaerobic ammonium-oxidizing bacteria) colonizes in granular sludge, and its abundance increases from 37.3% to 43.5%. Its abundance in granular sludge is 67.6 times and 4.5 times that in floc sludge and biofilm sludge respectively. Nitrosomonas (ammonia-oxidizing bacteria) shows a high abundance advantage in floc sludge, and its abundance increases from 7.5% to 13.2%. Its abundance in floc sludge is 1.9 times and 6.1 times that in biofilm sludge and granular sludge respectively. The denitrification representative bacterium SJA-28 is enriched in biofilm sludge, and its abundance increases from 2.3% to 16.5%. Its abundance in biofilm sludge is 1.8 times and 3.7 times that in floc sludge and granular sludge respectively. In addition, fermentative bacteria are enriched in floc sludge. The abundance of the representative bacterium OLB8 increases from 0.8% to 5.6%. Its abundance in biofilm sludge is 3.3 and 13.3 times that in floc sludge and granular sludge respectively. The distribution and enrichment of functional microorganisms in different forms of sludge in the SNADF system are beneficial to enhancing the collaborative relationship of various denitrifying functional bacteria, and thus improving the overall effect of the sewage treatment system.

[0029] 5. The carbon self-supplying SNADF process solves the problem of insufficient carbon source in the denitrification of high ammonia-nitrogen and low C / N wastewater and realizes nearly zero discharge of excess sludge, and has wide market applications. High ammonia-nitrogen and low C / N wastewater represented by anaerobic digestion liquid of breeding wastewater, landfill leachate, chemical fertilizer wastewater, and monosodium glutamate wastewater face problems such as insufficient carbon source and low total nitrogen removal rate in the biological treatment process, and urgently need efficient new biological treatment methods. The carbon self-supplying SNADF process converts endogenous biomass into available carbon sources, solves the problem of insufficient carbon source in the denitrification of high ammonia-nitrogen and low C / N wastewater and realizes nearly zero discharge of excess sludge, which has the significance of sustainable development and is a new breakthrough in the research of biological denitrification technology. The present invention completes the start-up and operation of the carbon self-supplying SNADF in a 2000L-scale device, and the daily wastewater treatment capacity can reach 3000L, which has important engineering demonstration significance and provides strong evidence for the feasibility of its practical application. Description of the Drawings

[0030] Figure 1 Schematic diagram of an SNADF high - efficiency biological nitrogen removal device based on endogenous biomass fermentation;

[0031] Figure 2 Operating performance of a carbon - self - supplying SNADF nitrogen removal system;

[0032] Figure 3 Variation of sludge concentration of flocculent sludge during the operation of a carbon - self - supplying SNADF system;

[0033] Figure 4 Variation of sludge production after the establishment of a carbon - self - supplying SNADF system;

[0034] Figure 5 Antibiotic removal performance of a carbon - self - supplying SNADF system;

[0035] In the figure: sewage water pump 1, livestock and poultry wastewater pump 2, membrane module 3, water outlet pump 4, liquid level sensor 5, first air flowmeter 6, screw blower 7, disc aerator 8, heater 9, biofilm carrier 10, polyurethane sponge carrier 11, gas collection hood 12, circulation fan 13, membrane flushing module 14, second air flowmeter 15, spray defoaming mechanism 16, spray nozzle 17, third air flowmeter 18. Specific implementation mode

[0036] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present invention.

[0037] If not specifically specified, the technical means used in the implementation examples are conventional means well - known to those skilled in the art.

[0038] The present invention discloses an SNADF high - efficiency biological nitrogen removal method based on endogenous biomass fermentation, including the following steps: (1) Initiation and operation of the partial nitrification (PN) process; (2) Initiation and operation of the partial nitrification / anaerobic ammonium oxidation (PNA) process; (3) Initiation and stable operation of the carbon - self - supplying SNADF process based on a continuous starvation strategy and a dissolved oxygen feedback regulation mechanism.

[0039] The specific process is as follows:

[0040] (1) During the start-up process of PN, by controlling the strategies of free ammonia (FA) and dissolved oxygen, the free ammonia is maintained at 20 - 30 mg / L, the dissolved oxygen is maintained at 1 - 2 mg / L, the pH is controlled at 6.8 - 8.5, and the ratio of the effluent ammonia nitrogen and nitrite concentration is close to 1:1, that is, the short-cut nitrification (PN) process is successfully started, and the abundance of Nitrosomonas is higher than 1%.

[0041] Among them, the short-cut nitrification (PN) process is started by inoculating the return sludge from the secondary sedimentation tank into the reactor, and the initial sludge concentration is 4 - 5 g MLSS / L; during the start-up stage of the short-cut nitrification process, the influent ammonia nitrogen is controlled at 150 - 250 mg / L by diluting the livestock and poultry wastewater with urban sewage; after the short-cut nitrification process is successfully started, the proportion of urban sewage influent is reduced by 10% every 5 - 10 days until it is zero, and the influent ammonia nitrogen concentration is 800 - 900 mg / L, meeting the load requirements for the nitritation of high ammonia nitrogen livestock and poultry wastewater. Before inoculating Anammox granular sludge, by reducing the influent ammonia nitrogen concentration and controlling the dissolved oxygen, the ammonia nitrogen and nitrite concentrations in the effluent of the PN process are both controlled at about 80 - 150 mg / L, and the ratio of the effluent ammonia nitrogen and nitrite concentration is close to 1:1.

[0042] (2) During the start-up process of PNA, Anammox granular sludge is inoculated, and the dominant strain in the granular sludge is Candidatus_Kuenenia, with a relative abundance higher than 10%. After inoculating the granular sludge, a biofilm carrier is placed. During the operation stage of PNA, the dissolved oxygen is controlled at 0.3 - 0.5 mg / L, the pH is controlled at 7.5 - 8.0, and the total nitrogen removal rate of the reactor is higher than 85%, that is, the short-cut nitrification / anaerobic ammonium oxidation (PNA) process is successfully started.

[0043] Among them, the concentration of inoculated Anammox granular sludge is 3 - 4 g MLSS / L. After the start-up of the PNA process, the proportion of urban sewage is reduced, and the proportion of urban sewage influent is reduced by 10% every 5 - 15 days until it is zero. During the period of reducing the proportion of urban sewage influent, the effluent maintains an ammonia nitrogen concentration of 20 - 50 mg / L and a nitrous acid concentration of 10 - 30 mg / L. After the reactor treats 100% of the livestock and poultry wastewater, the effluent is controlled to maintain an ammonia nitrogen concentration of 10 - 20 mg / L and a nitrous acid concentration of 0 - 10 mg / L. During the operation of the PNA process, the dissolved oxygen is maintained at 0.1 - 0.3 mg / L.

[0044] (3) A method for forming and directionally enriching fermentation strains OLB8 and Pedosphaeraceae based on a starvation strategy with carbon source limitation to complete the rapid start-up of SNADF.

[0045] Method for directional enrichment of fermentation strains: By regulating the carbon source supply, in the starvation environment after stopping the carbon source supply, Anaerolineaceae bacteria that use influent organic matter as a metabolic substrate can be selectively eliminated, reducing the competitive effect of non-target strains. Eventually, OLB8 bacteria and Pedosphaeraceae bacteria that use endogenous organic matter (such as extracellular polymeric substances and cell lysis products) as a metabolic substrate are successfully enriched. This process promotes the growth advantage of OLB8 bacteria and Pedosphaeraceae bacteria, and then the available carbon source generated by decomposing endogenous organic matter supports the growth of denitrifying bacteria (such as SJA-28, Denitratisoma, Kapabacteriales), eliminating the nitrate by-products generated in the Anammox process and completing the startup of the SNADF process.

[0046] The starvation strategy is operated as follows: The C / N ratio is adjusted from 1 - 1.5 to 0 - 0.1, the temperature is adjusted from 30 - 35°C to 20 - 25°C within 1 - 2 hours, the HRT is adjusted from 16 - 20 hours to 48 - 60 hours, and the starvation strategy time is 36 - 48 hours. After the starvation strategy, the C / N is restored to 1 - 1.5, the temperature is restored to 30 - 35°C within 1 - 2 hours, and the HRT is restored to 16 - 20 hours. The recovery period is 48 - 60 hours, and then the starvation strategy is carried out, repeated 3 - 5 times. During this period, the dissolved oxygen is controlled at 0.02 - 0.1 mg / L, and the oxidation-reduction potential is controlled between -50 mV and -200 mV. During the implementation of the starvation strategy, the ammonia nitrogen in the reactor effluent shall not be higher than 50 mg / L, and the nitrite concentration shall not be higher than 20 mg / L. The total nitrogen removal rate of the reactor is higher than 93%, indicating that the startup of the carbon self-supplied denitrification and fermentation (SNADF) process is successful.

[0047] Among them, during the operation of the denitrification and fermentation (SNADF) process, the C / N is adjusted to 0.1 - 0.3, the temperature is maintained at 32 - 35°C, the HRT is maintained at 12 - 18 hours, the dissolved oxygen is maintained at 0.02 - 0.08 mg / L, and the oxidation-reduction potential is controlled at -0 mV to -200 mV; the effluent maintains an ammonia nitrogen concentration of 0 - 15 mg / L and a nitrite concentration of 0 - 5 mg / L.

[0048] (4) Based on the dissolved oxygen feedback regulation mechanism, strengthen the ecological niche advantages of functional microorganisms in different forms of sludge (flocs, granules, biofilms) to maintain the efficient and stable operation of the SNADF process.

[0049] During the operation of the carbon self-supplying SNADF process, a parameter feedback regulation mechanism is set. When the dissolved oxygen concentration is between 0.01 and 0.05 mg / L, continuous aeration is adopted. When the dissolved oxygen concentration is between 0.05 and 0.1 mg / L, intermittent aeration (5 minutes of aeration + 5 minutes of static settlement) is adopted. When the dissolved oxygen is higher than 0.1 mg / L, aeration is stopped. While providing dissolved oxygen, the oxygen transfer difference in different types of sludge is amplified to achieve the directional enrichment of different functional microorganisms in different types of sludge. During the operation, Candidatus Kuenenia is maintained to be enriched in the granular sludge with a relative abundance of not less than 20%; OLB8 is enriched in the flocculent sludge with a relative abundance of not less than 5%; SJA-28 is enriched in the biofilm with a relative abundance of not less than 10%.

[0050] The present invention also discloses a device used for the SNADF high-efficiency biological nitrogen removal method based on endogenous biomass fermentation, as Figure 1 shown, including a reactor, specifically an MBR reactor. The reactor pumps urban sewage and high-ammonia-nitrogen livestock wastewater into the reactor in proportion through a sewage water pump 1 and a livestock wastewater pump 2 to adjust the influent ammonia-nitrogen concentration. The effluent is discharged through an effluent pump 4 connected to a membrane module 3. A liquid level sensor 5 is arranged in the reactor to control the start and stop of the effluent and maintain the liquid level at 2.00 ± 0.02 m. A screw blower 7 equipped with a first air flow meter 6 is connected to a disc aerator 8. The disc aerator 8 is located at the bottom of the reactor to provide the dissolved oxygen required for operation and complete the full mixing of the sludge and the wastewater. A heater 9 is arranged in the reactor to maintain the temperature at about 30 °C during the operation of the equipment. As one of the implementation manners, the reactor is of a box structure with length, width and height of 1 m × 1 m × 2.2 m respectively, and the effective volume is 2 m 3 , and the pH value in the reactor is adjusted by adding KHCO 3 .

[0051] Furthermore, a biofilm carrier 10 is arranged in the reactor. As one of the implementation manners, the biofilm carrier is a hollow carrier ball with a plastic material on the outside. The diameter of the hollow carrier ball is 15 cm, and the pore diameter on the hollow carrier ball is 1 - 1.5 cm. Inside the hollow carrier ball, 8 - 10 polyurethane sponge carriers 11 are installed. The polyurethane sponge carrier has a size of 3 × 3 × 3 cm; the specific surface area is 15000 m 2 / m 3 , and the specific gravity is 0.91 g / cm 3 .

[0052] Further, a gas collecting hood 12 is provided at the top of the reactor, and a membrane scouring module 14 is provided at the bottom of the membrane module 3. The membrane scouring module 14 is connected to a circulation fan 13 equipped with a second air flow meter 15. The air entering the reactor through the disk aerator 8 forms oxygen-deficient air after the sludge consumes oxygen, and the circulation fan 13 provides the oxygen-deficient air for the membrane scouring module 14 and passes through the second air flow meter 15 to relieve the MBR membrane pollution. The scouring air volume and the water output are controlled at 15-20:1.

[0053] Further, to prevent the accumulation of bubbles on the liquid surface of the reactor pool from interfering with the liquid level recognition of the liquid level sensor 5, a spray defoaming mechanism 16 is provided above the membrane module 3 in the reactor. The spray defoaming mechanism 16 is connected to the circulation fan 13 through a third air flow meter 18. The pipeline diameter of the air-lift spray defoaming mechanism 16 is 4-8 cm, and the gas source is the oxygen-deficient air provided by the circulation fan 13. The gas-liquid mixture is sprayed out from the spray nozzle 17 on the pipeline, and the spray flow rate is controlled by the third air flow meter 18, and the air flow rate is controlled at 1-2 m 3 / h.

[0054] The present invention will be further described below in conjunction with specific embodiments.

[0055] Embodiment 1

[0056] 1. An SNADF high-efficiency biological nitrogen removal device based on endogenous biomass fermentation, the device structure of which is as Figure 1 shown, and the specific structure is as disclosed above.

[0057] Among them, the liquid level sensor 5 in the reactor maintains the liquid level at 2.00 ± 0.02 m. During the operation of the equipment, the heater 9 is used to maintain the temperature at about 30°C. The MBR reactor is a box structure with a length, width and height of 1 m × 1 m × 2.2 m respectively, and the effective volume is 2 m 3 , and the pH value in the reactor is adjusted by adding KHCO 3 .

[0058] Among them, the biological membrane carrier 10 is a hollow carrier ball with a plastic material on the outside. The diameter of the hollow carrier ball is 15 cm, and the pore diameter on the hollow carrier ball is 1.5 cm. There are 10 polyurethane sponge carriers 11 inside the hollow carrier ball. The urethane sponge carrier has a size of 3 × 3 × 3 cm; the specific surface area is 15000 m 2 / m 3 , and the specific gravity is 0.91 g / cm 3 .

[0059] The air entering the reactor through the disk aerator 8 forms oxygen-deficient air after the sludge consumes oxygen, and the oxygen-deficient air is provided to the membrane scouring module 14 by the circulation fan 13 to alleviate the MBR membrane pollution. The scouring gas volume and the water output are controlled at 20:1.

[0060] The pipeline diameter of the air-lift spray defoaming mechanism 16 is 5 cm. The gas source is the oxygen-deficient air provided by the circulation fan 13. The gas-liquid mixture is sprayed out from the spray nozzle 17, and the spray flow rate is controlled by the third air flowmeter 18. The air flow rate is controlled at 1.5 m 3 / h.

[0061] 2. An SNADF high-efficiency biological nitrogen removal method based on endogenous biomass fermentation, which includes the following steps: (1) Start-up and operation of the partial nitrification (PN) process; (2) Start-up and operation of the partial nitrification / anaerobic ammonium oxidation (PNA) process; (3) Rapid start-up and operation of the carbon self-supplying SNADF process under a continuous starvation strategy.

[0062] Specifically: (1) During the PN start-up process, by controlling the strategies of free ammonia (FA) and dissolved oxygen, FA is maintained at 25 mg / L, the dissolved oxygen is maintained at about 1.5 mg / L, the pH is controlled at 7.2 - 8.2. When the ratio of the ammonia nitrogen and nitrite concentration in the effluent is close to 1:1, it is regarded as the successful start-up of the PN process, and the abundance of Nitrosomonas is higher than 1%.

[0063] Among them, the reactor inoculates the return sludge from the secondary sedimentation tank to start the PN process. The initial sludge concentration is 4.5 g MLSS / L. During the start-up stage of the PN process, the urban sewage is used to dilute the livestock and poultry wastewater to control the influent ammonia nitrogen at 150 mg / L. After the successful start-up of the PN process, the proportion of urban sewage influent is reduced by 10% every 5 days until it is zero, and the influent ammonia nitrogen concentration is 850 mg / L, meeting the load requirements for the nitritation treatment of high-ammonia-nitrogen livestock and poultry wastewater.

[0064] Before inoculating Anammox granular sludge, by reducing the influent ammonia nitrogen concentration and controlling the dissolved oxygen, both the ammonia nitrogen and nitrite concentration in the effluent of the PN process are controlled at about 120 mg / L, and the ratio of the ammonia nitrogen and nitrite concentration in the effluent is close to 1:1.

[0065] (2) During the PNA start-up process, Anammox granular sludge is inoculated. The dominant strain in the granular sludge is Candidatus_Kuenenia, and the relative abundance is higher than 10%. After inoculating the granular sludge, a biofilm carrier is placed. During the PNA operation stage, the dissolved oxygen is controlled at about 0.3 mg / L, the pH is controlled at 7.5 - 8.0. When the total nitrogen removal rate of the reactor is higher than 85%, it is regarded as the successful start-up of the PNA process.

[0066] Among them, the concentration of inoculated Anammox granular sludge is 3 g MLSS / L. After the start-up of the PNA process, the proportion of municipal sewage is reduced, and the proportion of municipal sewage inflow is reduced by 10% every 7 days until it reaches zero. During the period of reducing the proportion of municipal sewage inflow, the ammonia nitrogen concentration in the effluent is maintained at about 20 mg / L, and the nitrite concentration is maintained at about 10 mg / L. After the reactor treats 100% of the livestock and poultry wastewater, the ammonia nitrogen concentration in the effluent is controlled to be about 15 mg / L, and the nitrite concentration is about 5 mg / L. During the operation of the PNA process, the dissolved oxygen is maintained at about 0.2 mg / L.

[0067] (3) The starvation strategy operation for the rapid start-up of the carbon self-supplying SNADF process can achieve the rapid and directional enrichment of the target fermentative bacteria OLB8 and Pedosphaeraceae in the mixed flora. There is a phenomenon of multiple strains competing for substrates in the complex fermentation environment. The starvation environment after stopping the carbon source supply can selectively eliminate Anaerolineaceae that use influent organic matter as a metabolic substrate, reduce the competitive effect of non-target strains, enhance the growth advantages of OLB8 and Pedosphaeraceae that use endogenous organic matter (such as extracellular polymeric substances and cell lysis products) as a metabolic substrate, and promote the enrichment of the target bacteria. The available carbon sources generated by OLB8 and Pedosphaeraceae decomposing endogenous organic matter are used to support denitrifying bacteria (SJA-28, Denitratisoma, Kapabacteriales), eliminate the nitrate by-products generated in the Anammox process, and complete the start-up of the SNADF process.

[0068] The starvation strategy operation is as follows: The C / N ratio is adjusted from 1.2 to 0.1, the temperature is adjusted from 35 °C to 20 °C within 2 h, the HRT is adjusted from 16 h to 48 h, and the starvation strategy time is 48 h. After the starvation strategy, the C / N is restored to 1.5, the temperature is restored to 35 °C within 2 h, and the HRT is restored to 16 h. The recovery period is 48 h, and then the starvation strategy is carried out. This is repeated 3 - 5 times. During this period, the dissolved oxygen is controlled at 0.02 - 0.08 mg / L, and the oxidation-reduction potential is controlled at about -150 mV. During the implementation of the starvation strategy, the ammonia nitrogen in the reactor effluent shall not be higher than 50 mg / L, and the nitrite concentration shall not be higher than 20 mg / L. When the total nitrogen removal rate of the reactor is higher than 93%, it is considered that the start-up of the carbon self-supplying SNADF process is successful.

[0069] Among them, during the operation of the SNADF process, the C / N is adjusted to about 0.25, the temperature is maintained at 32 °C, the HRT is maintained at 16 h, the dissolved oxygen is maintained at 0.02 - 0.08 mg / L, and the oxidation-reduction potential is controlled at about -50 mV. The ammonia nitrogen concentration in the effluent is maintained at about 10 mg / L, and the nitrite concentration is about 2 mg / L.

[0070] (4) Based on the dissolved oxygen feedback regulation mechanism, strengthen the ecological niche advantages of functional microorganisms in different forms of sludge (flocs, granules, biofilms), and maintain the efficient and stable operation of the SNADF process.

[0071] During the operation of the carbon self-sufficient SNADF process, a parameter feedback regulation mechanism is set. When the dissolved oxygen concentration is between 0.01 and 0.05 mg / L, continuous aeration is adopted. When the dissolved oxygen concentration is between 0.05 and 0.1 mg / L, intermittent aeration (5 minutes of aeration + 5 minutes of static) is adopted. When the dissolved oxygen is higher than 0.1 mg / L, aeration is stopped. While providing dissolved oxygen, amplify the oxygen transfer difference in different types of sludge to achieve the directional enrichment of different functional microorganisms in different types of sludge. During the operation, maintain Candidatus Kuenenia enriched in granular sludge with a relative abundance of not less than 20%; enrich OLB8 in floc sludge with a relative abundance of not less than 5%; enrich SJA-28 in biofilm with a relative abundance of not less than 10%.

[0072] When the SNADF process in Example 1 is operating, NO in the influent and effluent of the reactor 3 - -N, NO 2 - -N, NH 4 + -N are detected daily (as Figure 2 shown), and according to different operation strategies, the operation is divided into 4 stages: Stage 1 (days 1 - 106, PN stage), Stage 2 (days 107 - 143, PNA startup stage), Stage 3 (days 144 - 178, PNA load increase stage), Stage 4 (days 184 - 260, SNADF stage).

[0073] During Stage 1, the rapid startup of the PN process is achieved within 10 days by controlling the aeration volume strategy. Subsequently, the influent NH 4 + -N concentration is increased to 800 - 1000 mg / L ( Figure 2 A) to investigate the flexibility of the PN process in treating high ammonia nitrogen wastewater. During the stable operation period (days 24 - 65), the average influent ammonia nitrogen of the PN process is 892.4 ± 50.6 mg / L, and the NO 2 - -N / NH 4 + -N average ratio is 1.1 ± 0.2 ( Figure 2 A and 2B). The results show that the PNA system can achieve effective NH 4 + -N conversion of high ammonia nitrogen wastewater and provide a reasonable substrate ratio for the Anammox process. At the end of Stage 1 (days 94 - 106), the effluent NH of the PN process is reduced by reducing the aeration volume4 + -N and NO 2 - -N was controlled at 114.8 ± 18.2 mg / L and 133.0 ± 11.2 mg / L respectively to prevent the inhibition of the activity of Anammox bacteria by high-concentration substrates.

[0074] After inoculating Anammox granular sludge in Stage 2, the PNA process was successfully started after 13 days of commissioning, and the TNRE was maintained above 80%. During the stable operation period (121 - 143 days), the average influent water of the PNA process was 366.6 ± 8.9 mg / L, and the effluent NH 4 + -N, NO 2 - -N, NO 3 - The average concentrations of -N were 11.0 ± 8.3 mg / L, 11.5 ± 9.0 mg / L and 23.9 ± 4.4 mg / L respectively. During this period, the NH 4 + -N removal rate (NRE) and total nitrogen removal rate (TNRE) were 97.0 ± 2.3% and 87.3 ± 8.33.3% respectively.

[0075] Since Stage 3, antibiotics were added and the influent NH 4 + -N concentration was gradually increased to simulate livestock and poultry wastewater. When increasing the influent NH 4 + -N concentration in the presence of antibiotics, the NRE and TNRE of the PNA process were 97.6 ± 3.3% and 88.6 ± 2.7% respectively, indicating that the three combined antibiotics of 2 + 2 + 2 mg / L did not inhibit the denitrification activity of PNA.

[0076] In Stage 4, a starvation strategy was implemented to investigate its impact on the denitrification performance of the MBR reactor. After the first starvation strategy, a large amount of ammonia nitrogen and nitrite remained in the effluent, and the TNRE decreased to 75.9%, indicating that this starvation strategy inhibited the Anammox activity. Subsequently, the influent load was reduced to maintain the denitrification performance of the reactor. Finally, the TNRE did not increase significantly and was maintained at 85.3 ± 4.9% (n = 10). To avoid the inhibition of Anammox activity, only COD was restricted in the second starvation strategy. On the 8th day after the implementation of the starvation strategy, the TNRE increased to 94.3%, indicating that this starvation strategy contributed to the rapid startup of the SNADF denitrification system. During the stable period of the SNADF system, the influent ammonia nitrogen was 828.9 ± 11.5%, and the TNRE and ΔCOD / TN were 95.9 ± 0.9% and 0.13 ± 0.01 respectively. Under similar influent load and ΔCOD / TN conditions, the TNRE of SNADF was 9.5% higher than that of PNA.

[0077] Example 2

[0078] The SNADF high-efficiency biological nitrogen removal device based on endogenous biomass fermentation in this example is the same as that in Example 1.

[0079] To reflect the high efficiency of the starvation strategy with carbon source limitation for the rapid startup of the SNADF process, the ammonia nitrogen removal rate and total nitrogen removal rate of the reactor were tested during the starvation strategy of stopping the supply of organic matter + nitrogen source and the starvation strategy of only stopping the supply of carbon source (carbon source limitation), and the effectiveness of the two starvation strategies for the startup of SNADF was compared (Table 1).

[0080] After 6 days of the starvation strategy of stopping the supply of organic matter + nitrogen source, the normal substrate supply of the reactor was restored. The average total nitrogen removal rate in the subsequent 20 days was 84.5%, indicating that the starvation strategy of stopping the supply of organic matter + nitrogen source was ineffective for starting the SNADF process. After 5 days of the starvation strategy of stopping the supply of carbon source, the normal substrate supply of the reactor was restored. The total nitrogen removal rate increased to 94.3% on the 8th day, and the average total nitrogen removal rate in the subsequent 12 days was 93.6%. It shows that this starvation strategy is helpful for the rapid startup of the SNADF nitrogen removal system. The results show that the starvation strategy of only stopping the supply of carbon source (carbon source limitation) can complete the rapid startup of the SNADF process within 8 - 14 days.

[0081] Table 1 Denitrification performance of the reactor after adopting the starvation strategy

[0082]

[0083]

[0084] Example 3

[0085] The SNADF high-efficiency biological nitrogen removal device based on endogenous biomass fermentation in this example is the same as that in Example 1.

[0086] To reflect the carbon self-supply ability and in-situ sludge reduction performance of the SNADF system, the sludge concentration of flocculent sludge during the operation of the MBR reactor was monitored (as Figure 3 ). The average sludge concentration (MLSS) of flocculent sludge in Stage 2 was 9.6 g / L and did not show significant growth. As the substrate concentration increased continuously in Stage 3, the MLSS of flocculent sludge increased from 9.4 g / L to 10.9 g / L and reached the highest value (12.2 g / L) after the first starvation strategy. After the second starvation strategy, the MLSS of flocculent sludge stopped growing and remained at 1.20 g / L. After calculation, after the second starvation strategy, the MLSS of flocculent sludge stopped growing and remained at 12.0 g / L. After calculation, the sludge yield (Y obs) were 0.197±0.0388 kg MLSS / kgCOD and 0.017±0.012 kg MLSS / kgCOD respectively, a 11.7-fold decrease (as Figure 4 ). Under the same nutrient environment, the significant decrease of Y obs indicates that after the establishment of the SNADF system, fermentative bacteria decompose organic matters (such as EPS, BAP) in the sludge, realizing the self-supply of carbon source for the denitrification process and reducing the excess sludge production by 91.5%. According to the COD consumption values of complete denitrification and shortcut denitrification, the fermentation process can provide 133.9 - 228.4 mg COD for the SNADF system. Therefore, the COD-limited starvation strategy can complete the rapid establishment of the fermentation process of the carbon self-supply type SNADF system and effectively improve the nitrogen removal performance of the reactor.

[0087] Example 4

[0088] The SNADF high-efficiency biological nitrogen removal device based on endogenous biomass fermentation in this example is the same as that in Example 1.

[0089] The influent and effluent concentrations and removal rates of three antibiotics, SMX, CIP, and OTC, in the SNADF system during operation were studied (as Figure 5 ). As the SMX concentration increased from 0.5 mg / L to 2.0 mg / L, the removal ability of the SNAD system for SMX gradually decreased, but the removal rate still remained at 77.2±2.1%. Similar to the result of SMX, the removal abilities of the SNAD system for CIP and OTC also gradually decreased with the increase of the antibiotic concentration, and the final removal rates remained at 86.1±1.9% and 91.1±0.9% respectively.

[0090] Example 5

[0091] The SNADF high-efficiency biological nitrogen removal device based on endogenous biomass fermentation in this example is the same as that in Example 1.

[0092] To reflect the enhancement effects of the starvation strategy and the dissolved oxygen feedback regulation mechanism on fermentation bacteria and denitrifying bacteria, the abundance changes of functional microorganisms in different functional sludges in the reactor were investigated. The initial stage and the SNADF stage in Example 1 were named Stage 1 and Stage 2 (see Table 2). The abundances of Nitrosomonas (AOB) in floc sludge, biofilm sludge, and granular sludge were 4.7% - 13.2%, 4.5 - 6.9%, and 0.6 - 2.2% respectively, and all showed an upward trend. Candidatus_Kuenenia (AnAOB), after the establishment of SNADF, its abundances in floc sludge, biofilm sludge, and granular sludge changed from 0.8%, 10.1%, 37.3% to 0.6%, 9.6%, 43.5% respectively. In addition, AnAOB was more inclined to colonize in granular sludge, and the abundances of AnAOB in granular sludge were 67.6 times and 4.5 times that of floc sludge and biofilm sludge respectively in the SNADF stage.

[0093] Denitrifying bacteria (DB) proliferated to varying degrees and were mainly enriched in biofilm sludge, such as SJA-28, Denitratisoma, Kapabacteriales. Among them, the change of SJA-28 was the most significant, increasing from 2.3% in the initial stage to 16.5% in the SNADF stage. In the light-dark feast-famine algal-bacterial reactor, SJA-28 can use acetic acid for denitrification. In addition, Kapabacteriales was also considered to have the potential to utilize acetate. The proliferation of denitrifying bacteria indicates that the fermentation process in the reactor can stably generate available carbon sources using endogenous organic matter as a substrate. The stable denitrification process is one of the important reasons for the efficient nitrogen removal performance of SNADF.

[0094] Under the starvation strategy, OLB8, Actinomarinales, and Pedosphaeraceae were significantly enriched in floc sludge as potential fermentation species, and their abundances increased to 6.5 times (from 0.8% to 5.6%), 12.5 times (from 0.3% to 4.0%), and 1.9 times (from 4.6% to 8.7%) of the initial stage respectively. OLB8, as a heterotrophic bacterium, has been widely reported to have the ability to degrade polysaccharides, proteins, and other complex molecules. However, the abundance of the typical hydrolytic acidifying bacterium Anaerolineaceae decreased by 11.4 times. The results show that in the initial stage, organic matter flowed more to Anaerolineaceae, while under the starvation strategy, endogenous organic matter was more inclined to flow to the energy metabolism pathways of species such as OLB8. In addition, the enrichment of fermentative bacteria promoted the rapid degradation of organic matter in the sludge, thereby reducing the production of excess sludge in SNADF. Generally speaking, under the starvation strategy, single denitrifying functional species in different ecological niches were enriched, which is beneficial to strengthening the cooperation among functional microorganisms and weakening the substrate competition phenomenon.

[0095] Table 2 Relative abundances of key functional species at the genus level in different types of sludge in the SNADF system

[0096]

[0097] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present invention.

[0098] The embodiments described above are only for describing the preferred mode of the present invention, and do not limit the scope of the present invention. Without departing from the design spirit of the present invention, various deformations and improvements made by those of ordinary skill in the art to the technical solution of the present invention shall fall within the protection scope determined by the claims of the present invention.

Claims

1. A SNADF efficient biological denitrification method based on endogenous biomass fermentation, characterized by: The following steps are involved: (1) Start-up of short-cut nitrification / anaerobic ammonium oxidation process In the reactor, sewage and livestock wastewater were added, and after the short-cut nitrification process was started, before the Anammox granular sludge was inoculated, the effluent ammonia nitrogen and nitrite concentrations were controlled at 80-150 mg / L, with a ratio close to 1:

1. During the short-cut nitrification / anaerobic ammonium oxidation operation stage, the dissolved oxygen was controlled at 0.3-0.5 mg / L, the pH was controlled at 7.5-8.0, and the total nitrogen removal rate of the reactor was higher than 85%, indicating that the short-cut nitrification / anaerobic ammonium oxidation process was successfully started. (2) Start-up of the carbon-self-sufficient SNADF process by directing the enrichment of fermentation bacteria OLB8 and Pedosphaeraceae through a starvation strategy The C / N ratio was adjusted to 0-0.1, the temperature was adjusted to 20-25℃, the HRT was adjusted to 48-60h, and the starvation strategy time was 36-48h; after the starvation strategy, the C / N ratio was restored to 1-1.5, the temperature was restored to 30-35℃, the HRT was restored to 16-20h, and the recovery period was 48-60h; by stopping the carbon source supply, the Anaerolineaceae bacteria that used the influent organic matter as a metabolic substrate were selectively eliminated, and the OLB8 bacteria and Pedosphaeraceae bacteria that used the endogenous organic matter as a metabolic substrate were enriched; Then the starvation strategy was implemented, which was repeated 3 to 5 times, during which the dissolved oxygen was controlled at 0.02 to 0.1 mg / L, the redox potential was controlled at -50 mV to -200 mV, the ammonia nitrogen in the reactor effluent was not higher than 50 mg / L, the nitrite concentration was not higher than 20 mg / L, and the total nitrogen removal rate of the reactor was higher than 93%, which means that the carbon source self-sufficient SNADF process was successfully started; (3) Stable operation of the SNADF process based on dissolved oxygen feedback regulation mechanism When the dissolved oxygen concentration is between 0.01 and 0.05 mg / L, continuous aeration is used; when the dissolved oxygen concentration is between 0.05 and 0.1 mg / L, intermittent aeration is used, and aeration is stopped when the dissolved oxygen concentration is higher than 0.1 mg / L to achieve directional enrichment of microorganisms with different functions; During the operation, Candidatus Kuenenia was enriched in the granular sludge, with a relative abundance of not less than 20%; OLB8 was enriched in the flocculent sludge, with a relative abundance of not less than 5%; and SJA-28 was enriched in the biofilm, with a relative abundance of not less than 10%.

2. The SNADF efficient biological denitrification method based on endogenous biomass fermentation according to claim 1, characterized in that: In step (1), free ammonia is maintained at 20-30 mg / L, dissolved oxygen is maintained at 1-2 mg / L, and pH is controlled at 6.8-8.5, that is, the short-range nitrification process is successfully started.

3. The SNADF efficient biological denitrification method based on endogenous biomass fermentation according to claim 2, characterized in that: The short-cut nitrification process is started by inoculating the return sludge from the secondary sedimentation tank in the reactor, and the initial sludge concentration is 4-5g MLSS / L; during the startup phase of the short-cut nitrification process, the influent ammonia nitrogen is controlled at 150-250mg / L; after the short-cut nitrification process is successfully started, the sewage influent ratio is reduced by 10% every 5-10 days until it is zero, and the influent ammonia nitrogen concentration is 800-900mg / L.

4. The SNADF efficient biological denitrification method based on endogenous biomass fermentation according to claim 1, characterized in that: In step (1), the inoculated Anammox granular sludge has a sludge concentration of 3 to 4 g MLSS / L; after the short-cut nitrification / anaerobic ammonium oxidation process is started, the sewage inflow ratio is reduced by 10% every 5 to 15 days until it is zero; during the period of reducing the sewage inflow ratio, the effluent is maintained at an ammonia nitrogen concentration of 20 to 50 mg / L and a nitrite concentration of 10 to 30 mg / L; after the reactor treats 100% of the livestock and poultry wastewater, the effluent is controlled to maintain an ammonia nitrogen concentration of 10 to 20 mg / L and a nitrite concentration of 0 to 10 mg / L; during the operation of the short-cut nitrification / anaerobic ammonium oxidation process, the dissolved oxygen is maintained at 0.1 to 0.3 mg / L.

5. The SNADF efficient biological denitrification method based on endogenous biomass fermentation according to claim 1, characterized in that: In step (2), during the operation of the carbon-based SNADF process, C / N is adjusted to 0.1-0.3, the temperature is maintained at 32-35°C, the HRT is maintained at 12-18h, the dissolved oxygen is maintained at 0.02-0.08mg / L, and the redox potential is controlled at -0mV--200mV; the effluent maintains an ammonia nitrogen concentration of 0-15mg / L and a nitrite concentration of 0-5mg / L.

6. A device used in the SNADF efficient biological denitrification method based on endogenous biomass fermentation according to any one of claims 1 to 5, characterized in that: The invention comprises a reactor, wherein water is taken in by a sewage pump (1) and a livestock and poultry wastewater pump (2), and effluent is discharged by an effluent pump (4) connected to a membrane assembly (3). A screw blower (7) equipped with a first air flow meter (6) is connected to a disc aerator (8), and a biofilm carrier (10), a liquid level sensor (5) and a heater (9) are arranged in the reactor.

7. The SNADF efficient biological denitrification device based on endogenous biomass fermentation according to claim 6, characterized in that: A gas collecting hood (12) is arranged on the top of the reactor, a membrane flushing module (14) is arranged on the bottom of the membrane assembly (3), and the membrane flushing module (14) is connected to a circulation fan (13) equipped with a second air flow meter (15).

8. The SNADF high-efficiency biological denitrification device based on endogenous biomass fermentation according to claim 6, characterized in that: A spray defoaming mechanism (16) is provided above the membrane assembly (3) in the reactor, and the spray defoaming mechanism (16) is connected to the circulation fan (13) via a third air flow meter (18).

9. The SNADF high-efficiency biological denitrification device based on endogenous biomass fermentation according to claim 6, characterized in that: The biofilm carrier (10) is a hollow carrier ball, and 8 to 10 polyurethane sponge carriers (11) are installed in the hollow carrier ball.

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