Sludge fermentation driven biological denitrification process strengthening method based on anammox bacterium ultra-high-speed in-situ enrichment

Abstract

The invention relates to the technical field of sewage treatment, in particular to a sludge fermentation driven biological denitrification process strengthening method based on anammox bacterium ultrahigh-speed in-situ enrichment. Aiming at a sludge fermentation driven biological nitrogen removal (SFBNR) process, a hydrogen production functional strain, namely JABWBG01sp013360575, is directionally cultivated in an in-situ fermentation-denitrification continuous stirred reactor (SIFT-CSTR) in the process through an operation strategy of short-term HRT lifting and biological carrier adding, and a nitrogen metabolism electron pool of anaerobic ammonium oxidation bacteria (AnAOB) is amplified by utilizing high-energy H2 generated by the strain, so that the anaerobic ammonium oxidation bacteria (AnAOB) can be degraded, and the anaerobic ammonium oxidation bacteria (AnAOB) can be degraded. And thus, carbon sequestration and cell component synthesis driven by the carbon sequestration are accelerated, ultrahigh-speed in-situ enrichment of AnAOB is realized, high-efficiency removal of NH4 < + > from fermentation effluent is promoted, and the overall denitrification effect of an SFBNR process is optimized.

Description

Technical Field

[0001] The invention relates to the technical field of sewage treatment, and in particular to a method for enhancing a sludge fermentation-driven biological denitrification process based on ultra-high-speed in-situ enrichment of anammox bacteria. Background Art

[0002] Excessive nitrogen discharge seriously harms water bodies and human health. Most wastewater treatment plants rely on traditional nitrification-denitrification processes for nitrogen removal. However, due to the large amount of external carbon source required for denitrification, as well as the high cost and carbon footprint of waste sludge (WAS) treatment, this process has huge sustainability issues. Since organic carbon sources can be produced in WAS fermentation, sludge fermentation-driven biological denitrification (SFBNR) processes provide a sustainable option for nitrogen removal. However, NH4 + Anammox (anaerobic ammonium oxidation) is an emerging economical and efficient technology that can convert NH4 + and denitrification intermediate NO2 - In the laboratory-scale SFBNR process, inoculation of external anaerobic ammonium oxidizing bacteria (AnAOB) to remove NH4 from fermentation wastewater + The feasibility of the SFBNR process has been verified. However, the availability of these external AnAOBs is limited and their adaptability is poor. Therefore, the development of an in-situ ultra-high-speed enrichment strategy for AnAOB is the key to the sustainable application of the SFBNR process. Summary of the invention

[0003] Based on the above content, the present invention provides a sludge fermentation-driven biological denitrification process intensification method based on ultra-high-speed in-situ enrichment of anammox bacteria.

[0004] To achieve the above object, the present invention provides the following solutions:

[0005] The present invention provides a sludge fermentation-driven biological denitrification process intensification method based on ultra-high-speed in-situ enrichment of anammox bacteria. In an in-situ fermentation-denitrification continuous stirred reactor (SIFD-CSTR) of a sludge fermentation coupled biological denitrification (SFBNR) process, a hydrogen-producing functional strain, namely JABWBG01 sp013360575, is directedly cultivated through the following steps (the high-energy H2 produced by the strain can significantly amplify the nitrogen metabolism electron pool of anammox bacteria (AnAOB), thereby accelerating carbon fixation and the synthesis of cell components driven by it, fundamentally realizing ultra-high-speed in-situ enrichment of AnAOB, so as to significantly improve the denitrification efficiency of the SFBNR process):

[0006] (1) Initial operation stage: The hydraulic retention time (HRT) was maintained at 14-18 h, and the reactor was operated until the denitrification efficiency (DNE) reached 80%-85%, and the sludge reduction rate (SRE) reached 35%-45%; the relative abundances of JABWBG01sp013360575 and AnAOB in the suspended sludge were 2-5% and 0%, respectively, and the absolute abundance of AnAOB in the suspended sludge was 0 copies / gVSS; NH4 + The removal rate is 1% to 10%;

[0007] (2) Carrier addition and HRT enhancement stage: biological carriers were added to the reactor to increase the hydraulic retention time to 30-34 h, so that the denitrification efficiency reached 85%-90% and the sludge reduction rate reached 45%-55%. The relative abundances of JABWBG01sp013360575 and AnAOB on the biofilm increased from 0% to 25%-30% and 7%-9%, respectively. The absolute abundance of AnAOB on the biofilm was 1.58*10 9 ~1.72*10 9 copies / gVSS; NH4 + The removal rate is 10% to 30%;

[0008] (3) HRT reduction stage: reduce the hydraulic retention time to 12-14 h, operate until the denitrification efficiency reaches 90%-95%, and the sludge reduction rate reaches 65%-75%; the relative abundance of JABWBG01 sp013360575 and AnAOB on the biofilm increases to 60%-70% and 20%-24%, respectively, and the absolute abundance of AnAOB on the biofilm is 5.29*10 12 ~7.23*10 12 copies / gVSS; NH4 + The removal rate is 80% to 85%, indicating that the ultra-high-speed in-situ enrichment of AnAOB is completed and deep denitrification is achieved.

[0009] The sludge fermentation-driven biological denitrification process comprises a sequencing batch nitrification reactor, an in-situ fermentation-denitrification continuous stirring reactor, a sedimentation tank and a sludge tank.

[0010] In the present invention, suspended sludge refers to the sludge in the entire SIFD-CSTR reactor. The sludge in the SIFD-CSTR reactor is in a suspended state. After the subsequent addition of biological carriers, the sludge in the SIFD-CSTR reactor will exist in the form of suspension and biofilm. Therefore, in the initial operation stage, suspended sludge refers to the sludge in the reactor. The suspended sludge includes the inoculum sludge of the reactor and the added WAS from the sludge tank. The inoculum sludge and the added WAS both come from the secondary sedimentation tank of the sewage treatment plant, and the sludge particle size is 245-288um; the sludge MLSS and MLVSS in the sequencing batch nitrification reactor and the in situ fermentation-denitrification continuous stirred reactor are 6.5-15.6g / L and 2.9-7.8g / L, respectively.

[0011] In the present invention, the in-situ fermentation-denitrification continuous stirring reactor continuously receives the effluent from the sequencing batch nitrification reactor and the residual sludge in the sludge tank to achieve synchronous denitrification and sludge fermentation.

[0012] In the present invention, the sludge fermentation-driven biological denitrification process further comprises a secondary sedimentation tank, and the sludge in the secondary sedimentation tank is returned to the in-situ fermentation-denitrification continuous stirred reactor; the temperature in the in-situ fermentation-denitrification continuous stirred reactor is maintained at 33-35°C.

[0013] In the present invention, the biological carrier is a hydrophilic polyurethane foam carrier; the biological carrier has a dense porous structure, a porosity of ≥98%, and a specific surface area of ​​≥6000m 2 / m 3 .

[0014] In the present invention, the filling volume percentage of the biological carrier in the in-situ fermentation-denitrification continuous stirring reactor is 12.5%. The biological carrier is used for in-situ enrichment of AnAOB.

[0015] In the present invention, the influent of the sequencing batch nitrification reactor is domestic sewage; the NH4 + The concentration is 40-80mg / L, NO2 - The concentration is 1mg / L, NO3 - The concentration is 1mg / L.

[0016] In the present invention, each cycle of the sequencing batch nitrification reactor is 6 to 8 hours, including 5 stages: water inlet 30 to 50 minutes, aeration 1 to 3 hours, sedimentation 30 to 50 minutes, drainage 30 to 50 minutes, and the remaining time is an idle stage; at the beginning of each cycle, water with an exchange ratio of 50vt% is pumped into the sequencing batch nitrification reactor.

[0017] In the present invention, in the biological denitrification process driven by sludge fermentation, the NH4 +The conversion rate reaches 95%, which can provide sufficient NO3 for SIFD-CSTR - .

[0018] The present invention discloses the following technical effects:

[0019] The present invention focuses on the SIFD-CSTR in the SFBNR process. By reducing the HRT after a short-term boost and adding a biological carrier (single-module moving bed biofilm assembly) simultaneously, the efficient enrichment of the hydrogen-producing functional bacteria, namely JABWBG01sp013360575, in the reactor can be achieved. The high-energy H2 produced by the bacteria can expand the AnAOB nitrogen metabolism electron pool, thereby accelerating carbon fixation and the synthesis of cell components driven by it, fundamentally achieving ultra-high-speed in-situ enrichment of AnAOB, thereby promoting the production of effluent NH4 from fermentation. + The reduction makes it possible for the SFBNR process to achieve sustainable denitrification. Experiments have shown that this method is effective for the efficiency of the biological denitrification system driven by sludge fermentation based on ultra-high-speed in-situ enrichment of anammox bacteria.

[0020] Combined denitrification with sludge fermentation to produce NH4 + , CO2, H2, NO2 - On this basis, the increase and decrease of HRT can direct the cultivation of a hydrogen-producing functional bacteria species, namely JABWBG01 sp013360575, in the reactor. The high-energy H2 produced by this bacteria species can be used to expand the AnAOB nitrogen metabolic electron pool, which can promote the ultra-high-speed in situ enrichment of AnAOB.

[0021] Ultra-high-speed in-situ enrichment of AnAOB avoids inoculation of exogenous AnAOB sludge and is used for NO2 - The addition of special reactors required for production and the in-situ enriched AnAOB are more adaptable to the existing process environment, which is conducive to the stable operation of SIFD-CSTR.

[0022] In situ enrichment of AnAOB can remove the intermediate NH4 produced by sludge fermentation and denitrification + 、NO2 - , thereby promoting sludge reduction and denitrification from the perspective of substrate removal. In addition, since denitrification is driven by the sludge fermentation process, the increase in sludge reduction will further promote denitrification, thereby optimizing the overall denitrification effect of SIFD-CSTR. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0024] Figure 1 Schematic diagram of the sludge fermentation coupled biological denitrification process: 1. Water inlet barrel; 2. NF-SBR; 3. SIFD-CSTR; 4. Biological carrier; 5. Agitator; 6. Secondary sedimentation tank; 7. Air pump; 8. Aeration plate; 9. Sludge tank.

[0025] Figure 2 This is a graph showing the absolute and relative abundance changes of AnAOB in the SIFD-CSTR reactor in Example 1.

[0026] Figure 3 It is the AnAOB strain identified in the SIFD-CSTR reactor in Example 1.

[0027] Figure 4 It is the TPM of hydrogen-producing enzyme, key enzyme for carbon fixation, enzyme related to cell component synthesis in the SIFD-CSTR reactor in Example 1, as well as the changing trend of TPM of enzyme related to synthesis of each cell component. DETAILED DESCRIPTION

[0028] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as limiting the present invention, but should be understood as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0029] It should be understood that the terms described in the present invention are only for describing a particular embodiment and are not intended to limit the present invention. In addition, for the numerical range in the present invention, it should be understood that each intermediate value between the upper and lower limits of the scope is also specifically disclosed. The intermediate value in any stated value or stated range, and each smaller range between any other stated value or intermediate value in the described range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the scope.

[0030] Unless otherwise indicated, all technical and scientific terms used herein have the same meanings as those generally understood by those skilled in the art. Although the present invention describes only preferred methods and materials, any methods and materials similar or equivalent to those described herein may also be used in the implementation or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials associated with the documents. In the event of a conflict with any incorporated document, the content of this specification shall prevail.

[0031] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments of the present invention description without departing from the scope or spirit of the present invention. Other embodiments derived from the present invention description will be apparent to the skilled artisan. The present invention description and examples are exemplary only.

[0032] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0033] AnAOB fixes CO2 into acetyl-CoA via the Wood–Ljungdahl pathway (WLP). Acetyl-CoA then serves as a key precursor for the synthesis of cellular components and is used to support cell growth. Therefore, carbon fixation is the core metabolism that drives AnAOB growth. The efficient carbon fixation of AnAOB depends on high concentrations of reactants and electron donors: (1) CO2: reactant of WLP; (2) NH4 + and NO2 - :They synergistically drive the electron-producing reactions (3)-(4) and electron-consuming reactions (1)-(2) in nitrogen metabolism. Reactions (3)-(4) establish the electron pool for nitrogen metabolism and provide electron donors for reactions (1)-(2) and carbon fixation. The supply of these substances will help ensure the basic enrichment of AnAOB.

[0034] The electron-producing and electron-consuming reactions are shown below:

[0035] NO2 - +2H + +e - →NO+H2O(1)

[0036] NO+NH4 + +2H + +3e - →N2H4+H2O(2)

[0037] N2H4→N2+4H + +4e - (3)

[0038] NO2-→NO3 - +2H + +2e - (4)

[0039] Because fermentation bacteria can degrade excess sludge into CO2 and NH4 + , H2 and reducing equivalents, and the latter can promote NO2 in denitrification -The SFBNR process has the ability to provide the basic substrate environment required for the growth of AnAOB; at the same time, niche management strategies, such as integrating bio-carriers into flocs, can enhance the retention capacity and toxicity of AnAOB and minimize direct competition with heterotrophic organisms, thereby ensuring the in-situ enrichment of AnAOB on the biofilm. To this end, many studies have focused on achieving in-situ enrichment of AnAOB in the SFBNR process by adding bio-carriers. However, the enrichment rate in this way is still very slow. For example, the full-scale A2O process (1.4×10 5 m 3 ) as an example, after 600 days of operation, the relative abundance and absolute abundance of AnAOB in the biofilm were only 14.45% and 4×10 8 copies / g VSS.

[0040] The study found that the nitrogen metabolism electron pool is established only by reactions 3-4, and provides part of the electron donors for reactions 1-2, resulting in a shortage of electron donors required for efficient carbon fixation. Therefore, the key to accelerating the in situ enrichment of AnAOB is to supply a large amount of exogenous electron donors to expand the capacity of the nitrogen metabolism electron pool. H2, as a specific metabolite in the WAS fermentation process, has strong reducing power and high energy density, and can be preferentially used by AnAOB to drive electron-consuming reactions 1-2. AnAOB individuals with different H2 utilization abilities will show strong / weak electron-consuming reactions 1-2, thereby expanding the capacity of the nitrogen metabolism electron pool by introducing high-energy H2 or reducing electron-consuming reactions 1-2. In addition, appropriately increasing or decreasing the hydraulic retention time (HRT) in fermentation can promote the enrichment of hydrogen-producing bacteria such as JABWBG01 sp013360575 and elute methanogens, thereby strengthening H2 production and reducing H2 methane production, respectively. Therefore, in the SFBNR process, HRT regulation will be beneficial to the targeted cultivation of JABWBG01 sp013360575, and accelerate the in situ enrichment of AnAOB based on the high concentration of H2 produced by this strain.

[0041] Based on this, this study focused on the SFBNR process consisting of a sequencing batch nitrification reactor (NF-SBR), a continuously stirred in situ fermentation-denitrification reactor (SIFD-CSTR), a sedimentation tank, and a sludge tank. Aiming at the removal problem of fermentation-derived NH4+ in the SIFD-CSTR, a sludge fermentation-driven biological denitrification process intensification method based on ultra-high-speed in situ enrichment of anammox bacteria was developed, namely "HRT regulation + bio-carrier addition", which is crucial for intensifying process denitrification and achieving sustainable application.

[0042] The present invention provides a method for strengthening a sludge fermentation-driven biological denitrification process based on ultra-high-speed in-situ enrichment of anammox bacteria. The method is aimed at the sludge fermentation-driven biological denitrification (SFBNR) process. Through the operation strategy of "short-term HRT enhancement + biological carrier addition", a hydrogen-producing functional strain, namely JABWBG01 sp013360575, is cultivated in the in-situ fermentation-denitrification continuous stirred reactor (SIFD-CSTR) in the process. The high-energy H2 produced by the strain is used to amplify the nitrogen metabolism electron pool of anaerobic ammonia-oxidizing bacteria (AnAOB), thereby accelerating carbon fixation and the synthesis of cell components driven by it, and realizing ultra-high-speed in-situ enrichment of AnAOB to promote the effluent NH4 from fermentation. + Efficient removal, thereby optimizing the overall denitrification effect of the SFBNR process.

[0043] The embodiment of the present invention is based on the constructed sludge fermentation coupled biological denitrification (SFBNR) process. In the in situ fermentation-denitrification continuous stirred reactor (SIFD-CSTR) of the process, a hydrogen-producing functional strain, namely JABWBG01 sp013360575, is cultivated in a directional manner through the following steps. The high-energy H2 produced by the strain can significantly expand the nitrogen metabolism electron pool of anammox bacteria (AnAOB), thereby accelerating carbon fixation and the synthesis of cell components driven by it, fundamentally realizing the ultra-high-speed in situ enrichment of AnAOB, so as to significantly improve the denitrification efficiency of the SFBNR process. The specific steps are as follows:

[0044] (1) Initial operation stage: maintain the hydraulic retention time (HRT) at 14-18h, and operate until the denitrification efficiency (DNE) of the reactor reaches about 80%-85%, and the sludge reduction rate (SRE) reaches 35%-45%. The relative abundances of JABWBG01sp013360575 and AnAOB in suspended sludge are 2-5% and 0%, respectively. The relative abundances of the genes encoding the hydrogen production enzyme (Hyd) in JABWBG01 sp013360575, the key enzymes for carbon fixation (formate dehydrogenase (FDH) and CO dehydrogenase (CODH)) in AnAOB, and the enzymes related to cell component synthesis, i.e., TPM, are all 0. The absolute abundance of AnAOB in suspended sludge ranges from 0 copies / gVSS. NH4+ The removal rate is 1% to 10%.

[0045] (2) Carrier addition and HRT increase stage: biological carriers were added to the reactor to increase HRT to 30-34h, so that DNE reached about 85%-90% and SRE reached 45%-55%. The relative abundance of JABWBG01 sp013360575 and AnAOB on the biofilm increased from 0% to 25%-30% and 7%-9%, respectively, and the TPM of Hyd, FDH and CODH, and enzymes related to cell component synthesis increased to 0.01-0.0146, 0.0033-0.0055, and 0.1001-0.2001, respectively. The absolute abundance of AnAOB on the biofilm increased from 1.58*10 9 ~1.72*10 9 copies / gVSS. NH4 + The removal rate is 10% to 30%.

[0046] (3) HRT reduction stage: HRT was reduced to 12-14 h, and the DNE reached 90%-95%, and the SRE reached 65%-75%. The relative abundance of JABWBG01 sp013360575 and AnAOB on the biofilm increased to 60%-70% and 20%-24%, respectively, and the TPM of Hyd, FDH and CODH, and enzymes related to cell component synthesis increased to 0.1014-0.1265, 0.0275-0.0345, and 0.9264-1.2911, respectively. The absolute abundance of AnAOB on the biofilm increased from 5.29*10 12 ~7.23*10 12 copies / gVSS. NH4 + The removal rate is 80% to 85%, indicating that the ultra-high-speed in-situ enrichment of AnAOB is completed and deep denitrification is achieved.

[0047] The hydrogen-producing enzyme (Hyd) is used to produce H2; the key enzymes for carbon fixation are formate dehydrogenase (FDH) and CO dehydrogenase (CODH), which are used to synthesize acetyl-CoA; the cell component synthesis-related enzymes are all enzymes involved in the process of converting acetyl-CoA into carbohydrates, lipids and proteins.

[0048] The English meanings involved in the present invention are as follows:

[0049] MLSS: Mixed Liquor Suspended Solids Concentration

[0050] MLVSS: mixed liquor volatile suspended solids concentration

[0051] The technical solutions described in the present invention, unless otherwise specified, are all conventional solutions in the art, and the reagents or raw materials used, unless otherwise specified, are purchased from commercial channels or have been disclosed.

[0052] In an embodiment of the present invention, sludge samples were collected from SIFD-CSTR, and then these collected sludge samples were centrifuged at 5000 rpm for 15 minutes using a high-speed centrifuge at a temperature of 4 ° C. After centrifugation, the supernatant was poured off. The resulting mud sample was then exposed to liquid nitrogen for 10 minutes. The frozen samples were transported to a biological testing company with dry ice for molecular biology (high-throughput qPCR chip detection, macrogene detection + macrogene binning analysis) sequencing analysis. Among them, high-throughput qPCR chip detection is used to determine the absolute abundance of AnAOB in the sample, and macrogene detection + macrogene binning analysis is used to determine the relative abundance of JABWBG01 sp013360575 and AnAOB in the sample, as well as the relative abundance of genes encoding hydrogenase (Hyd), key enzymes for carbon fixation, and enzymes related to cell component synthesis, namely TPM. Molecular biological detection showed that JABWBG01sp013360575 bacteria were enriched.

[0053] The technical solutions provided by the present invention are described in detail below in conjunction with the embodiments, but they should not be construed as limiting the protection scope of the present invention.

[0054] Example 1

[0055] This embodiment provides a method for enhancing the biological denitrification process driven by sludge fermentation based on ultra-high-speed in-situ enrichment of anammox bacteria, using Figure 1 The SFBNR process shown in the figure comprises a NF-SBR 2 with effective volumes of 8 L, 8 L, 4 L, and 1 L, a SIFD-CSTR 3, a secondary sedimentation tank 6, and a sludge tank 9 (such as Figure 1 ); Among them, the wastewater in the water inlet bucket 1 is domestic sewage, and its main components are: NH4 + 40mg / L, NO2 - 1mg / L, NO3 -1mg / L, and intermittently introduced into NF-SBR; the inoculated sludge of NF-SBR and SIFD-CSTR, the exogenous WAS of sludge tank 9 are taken from the actual secondary sedimentation tank of the sewage plant, and the sludge particle size is 245-288um. In addition, the MLSS and MLVSS of the sludge in NF-SBR and SIFD-CSTR are 8.9g / L and 4.1g / L respectively; each cycle of NF-SBR is 8h, including 5 stages: 40min of water inlet, 1-3h of aeration, 40min of sedimentation, 40min of drainage, and the rest of the time is idle stage, and at the beginning of each cycle, 3L of wastewater from the water inlet bucket 1 is pumped into the reactor (i.e., 50% exchange ratio). In addition, during the aeration stage, air is introduced into the NF-SBR through the air pump 7 and the aeration plate 8; the reactor temperature of SIFD-CSTR is 35℃, the initial HRT is 16h, and cement mixing is continuously carried out through the agitator 5. In addition, the effluent of SIFD-CSTR3 continuously enters the secondary sedimentation tank 6 , the sludge in the secondary sedimentation tank 6 continuously flows back to SIFD-CSTR3 , and SIFD-CSTR3 continuously receives the sludge in the sludge tank 9 .

[0056] The present embodiment is based on the sludge fermentation driven biological denitrification process enhancement method of anammox bacteria ultra-high-speed in-situ enrichment, comprising the following steps:

[0057] (1) Start the SFBNR process for 30 days, NH4 + The conversion rate reaches 95%, and the effluent NH4 + 、NO2 - 、NO3 - 2mg / L, 1mg / L, and 38mg / L respectively. SIFD-CSTR effluent NH4 + 、NO2 - 、NO3 - 、DNE、SRE、NH4 + The removal rates were 20.9 mg / L, 1 mg / L, 5.7 mg / L, 85%, 40%, and 5%, respectively. Molecular biological tests found that the relative abundances of JABWBG01 sp013360575 and AnAOB in the suspended sludge on the 30th day were 3% and 0%, respectively, and the relative abundances of the genes encoding the hydrogen production enzyme (Hyd) in JABWBG01 sp013360575, the key carbon fixation enzymes (formate dehydrogenase (FDH) and CO dehydrogenase (CODH)) in AnAOB, and the enzymes related to cell component synthesis, i.e., TPM, were all 0, and the absolute abundance of AnAOB in the suspended sludge was 0 copies / gVSS. 1L of hydrophilic polyurethane foam carrier was added as biological carrier 4, with a porosity of 98% and a specific surface area of ​​6000m 2 / m 3 , and increase HRT to 32h.

[0058] (2) On the 90th day, NH4 + The conversion rate reaches 95%, and the effluent NH4 + 、NO2 - 、NO3 - 2mg / L, 1mg / L, and 38mg / L respectively. SIFD-CSTR effluent NH4 + 、NO2 - 、NO3 - 、DNE、SRE、NH4 + The removal rates were 17.6 mg / L, 1 mg / L, 3.8 mg / L, 90%, 50%, and 20%, respectively. The relative abundances of JABWBG01 sp013360575 and AnAOB on the biofilm increased to 25% and 7%, respectively. Figure 2 ), and AnAOB belongs to the genus Candidatus Brocadia ( Figure 3 The TPM of Hyd, key enzymes for carbon fixation, and enzymes related to cell component synthesis increased to 0.01, 0.0033, and 0.1001, respectively ( Figure 4 ), the absolute abundance of AnAOB in the biofilm is 1.58*10 9 copies / gVSS. Reduce HRT to 12h.

[0059] (3) On the 150th day, NH4 + The conversion rate reaches 95%, and the effluent NH4 + 、NO2 - 、NO3 - 2mg / L, 1mg / L, and 38mg / L respectively. SIFD-CSTR effluent NH4 + 、NO2 - 、NO3 - 、DNE、SRE、NH4 + The removal rates were 3.3 mg / L, 1 mg / L, 1.9 mg / L, 95%, 70%, and 85%, respectively. The relative abundances of JABWBG01 sp013360575 and AnAOB on the biofilm increased to 60% and 20%, respectively, and the TPMs of Hyd, key enzymes for carbon fixation, and enzymes related to cell component synthesis increased to 0.1014, 0.0275, and 0.9264, respectively. The absolute abundance of AnAOB on the biofilm was 5.29*10 12 The relative abundance and absolute abundance of AnAOB on the biofilm increased at a rate that was higher than that of the full-scale A2O process (1.4×10 5 m 3) increased by 4.54 times and 52900 times, respectively, indicating that AnAOB achieved ultra-high-speed in-situ enrichment, thus promoting NH4 + Efficient removal optimizes the overall denitrification effect of the process.

[0060] Example 2

[0061] This embodiment provides a method for enhancing the biological denitrification process driven by sludge fermentation based on ultra-high-speed in-situ enrichment of anammox bacteria, using Figure 1 The SFBNR process shown in the figure comprises a NF-SBR 2 with effective volumes of 8 L, 8 L, 4 L, and 1 L, a SIFD-CSTR 3, a secondary sedimentation tank 6, and a sludge tank 9 (such as Figure 1 ); Among them, the wastewater in the water inlet bucket 1 is domestic sewage, and its main components are: NH4 + 80mg / L, NO2 - 1mg / L, NO3 - 1mg / L, and intermittently introduced into NF-SBR; the inoculated sludge of NF-SBR and SIFD-CSTR, the exogenous WAS of sludge tank 9 are taken from the actual secondary sedimentation tank of the sewage treatment plant, and the sludge particle size is 245-288um. In addition, the MLSS and MLVSS of the sludge in NF-SBR and SIFD-CSTR are 8.9g / L and 4.1g / L respectively; each cycle of NF-SBR is 8h, including 5 stages: 40min of water inlet, 1-3h of aeration, 40min of sedimentation, 40min of drainage, and at the beginning of each cycle, 3L of wastewater from inlet bucket 1 is pumped into the reactor (i.e., 50% exchange ratio). In addition, during the aeration stage, air is introduced into NF-SBR through air pump 7 and aeration plate 8; the reactor temperature of SIFD-CSTR is 35℃, the initial HRT is 16h, and cement mixing is continuously carried out through agitator 5. In addition, the effluent of SIFD-CSTR3 continuously enters the secondary sedimentation tank 6 , the sludge in the secondary sedimentation tank 6 continuously flows back to SIFD-CSTR3 , and SIFD-CSTR3 continuously receives the sludge in the sludge tank 9 .

[0062] The present embodiment is based on the sludge fermentation driven biological denitrification process enhancement method of anammox bacteria ultra-high-speed in-situ enrichment, comprising the following steps:

[0063] (1) Start the SFBNR process for 30 days, NH4 + The conversion rate reaches 95%, and the effluent NH4 + 、NO2 - 、NO3 - 4mg / L, 1mg / L, and 76mg / L respectively. NH4 in the effluent of SIFD-CSTR + 、NO2 - 、NO3 -、DNE、SRE、NH4 + The removal rates were 22.8 mg / L, 1 mg / L, 15.2 mg / L, 80%, 40%, and 5%, respectively. The relative abundances of JABWBG01sp013360575 and AnAOB in suspended sludge were 3% and 0%, respectively, and the TPM of Hyd, key enzymes for carbon fixation, and enzymes related to cell component synthesis were all 0. The absolute abundance of AnAOB in suspended sludge was 0 copies / gVSS. 1 L of hydrophilic polyurethane foam carrier was added as biological carrier 4, with a porosity of 98% and a specific surface area of ​​6000 m 2 / m 3 , and increase HRT to 32h.

[0064] (2) On the 90th day, NH4 + The conversion rate reaches 95%, and the effluent NH4 + 、NO2 - 、NO3 - 4mg / L, 1mg / L, and 76mg / L respectively. NH4 in the effluent of SIFD-CSTR + 、NO2 - 、NO3 - 、DNE、SRE、NH4 + The removal rates were 19.2 mg / L, 1 mg / L, 11.4 mg / L, 85%, 50%, and 20%, respectively. The relative abundances of JABWBG01 sp013360575 and AnAOB on the biofilm increased to 30% and 9%, respectively, and the TPMs of Hyd, key enzymes for carbon fixation, and enzymes related to cell component synthesis increased to 0.0146, 0.0055, and 0.2001, respectively. The absolute abundance of AnAOB on the biofilm was 1.72*10 9 copies / gVSS. Reduce HRT to 12h.

[0065] (3) On the 150th day, NH4 + The conversion rate reaches 95%, and the effluent NH4 + 、NO2 - 、NO3 - 4mg / L, 1mg / L, and 76mg / L respectively. NH4 in the effluent of SIFD-CSTR + 、NO2 - 、NO3 - 、DNE、SRE、NH4 +The removal rates were 4.8 mg / L, 1 mg / L, 7.6 mg / L, 90%, 70%, and 80%, respectively. The relative abundances of JABWBG01 sp013360575 and AnAOB on the biofilm increased to 70% and 24%, respectively, and the TPMs of Hyd, key enzymes for carbon fixation, and enzymes related to cell component synthesis increased to 0.1265, 0.0345, and 1.2911, respectively. The absolute abundance of AnAOB on the biofilm was 7.23*10 12 The relative abundance and absolute abundance of AnAOB on the biofilm increased at a rate that was higher than that of the full-scale A2O process (1.4×10 5 m 3 ) increased by 5.64 times and 72300 times, respectively, indicating that AnAOB achieved ultra-high-speed in-situ enrichment, thus promoting NH4 + Efficient removal optimizes the overall denitrification effect of the process.

[0066] Comparative Example 1

[0067] This comparative example provides a method for enhancing the biological denitrification process driven by sludge fermentation based on ultra-high-speed in-situ enrichment of anammox bacteria. The only difference from Example 1 is that no HRT adjustment is performed. The specific method is as follows: Figure 1 The SFBNR process shown in the figure comprises a NF-SBR 2 with effective volumes of 8 L, 8 L, 4 L, and 1 L, a SIFD-CSTR 3, a secondary sedimentation tank 6, and a sludge tank 9 (such as Figure 1 ); Among them, the wastewater in the water inlet bucket 1 is domestic sewage, and its main components are: NH4 + 40mg / L, NO2 - 1mg / L, NO3 - 1mg / L, and intermittently introduced into NF-SBR; the inoculated sludge of NF-SBR and SIFD-CSTR, the exogenous WAS of sludge tank 9 are taken from the actual secondary sedimentation tank of the sewage treatment plant, and the sludge particle size is 245-288um. In addition, the MLSS and MLVSS of the sludge in NF-SBR and SIFD-CSTR are 8.9g / L and 4.1g / L respectively; each cycle of NF-SBR is 8h, including 5 stages: 40min of water inlet, 1-3h of aeration, 40min of sedimentation, 40min of drainage, and at the beginning of each cycle, 3L of wastewater from inlet bucket 1 is pumped into the reactor (i.e., 50% exchange ratio). In addition, during the aeration stage, air is introduced into NF-SBR through air pump 7 and aeration plate 8; the reactor temperature of SIFD-CSTR is 35℃, the initial HRT is 16h, and cement mixing is continuously carried out through agitator 5. In addition, the effluent of SIFD-CSTR3 continuously enters the secondary sedimentation tank 6 , the sludge in the secondary sedimentation tank 6 continuously flows back to SIFD-CSTR3 , and SIFD-CSTR3 continuously receives the sludge in the sludge tank 9 .

[0068] The in-situ enrichment method of anammox bacteria in this comparative example comprises the following steps:

[0069] (1) Start the SFBNR process for 30 days, NH4 + The conversion rate reaches 95%, and the effluent NH4 + 、NO2 - 、NO3 - 2mg / L, 1mg / L, and 38mg / L respectively. SIFD-CSTR effluent NH4 + 、NO2 - 、NO3 - 、DNE、SRE、NH4 + The removal rates were 20.9 mg / L, 1 mg / L, 5.7 mg / L, 85%, 40%, and 5%, respectively. The relative abundances of JABWBG01sp013360575 and AnAOB in suspended sludge were 3% and 0%, respectively, and the relative abundances of the coding genes of Hyd, key enzymes for carbon fixation, and enzymes related to cell component synthesis, i.e., TPM, were all 0. The absolute abundance of AnAOB in suspended sludge was 0 copies / gVSS. 1 L of hydrophilic polyurethane foam carrier was added as biological carrier 4, with a porosity of 98% and a specific surface area of ​​6000 m 2 / m 3 .

[0070] (2) On the 150th day, NH4 + The conversion rate reaches 95%, and the effluent NH4 + 、NO2 - 、NO3 - 2mg / L, 1mg / L, and 38mg / L respectively. SIFD-CSTR effluent NH4 + 、NO2 - 、NO3 - 、DNE、SRE、NH4 + The removal rates were 18.7 mg / L, 1 mg / L, 5.7 mg / L, 85%, 45%, and 15%, respectively. During the operation of the reactor, from day 0 to day 150, the relative abundances of JABWBG01sp013360575 and AnAOB on the biofilm increased to 6% and 4%, respectively, and the TPMs of Hyd, key enzymes for carbon fixation, and enzymes related to cell component synthesis increased to 0.0052, 0.0024, and 0.0892, respectively. The absolute abundance of AnAOB on the biofilm reached 3.04*10 10 The absolute abundance and relative abundance of AnAOB on the biofilm were only 1 / 5 and 1% of those in Example 1, respectively, indicating that the in situ enrichment of AnAOB was slow, resulting in NH4+ The removal effect is poor, which is not conducive to optimizing the overall denitrification effect of the process.

[0071] Comparative Example 2

[0072] This comparative example provides a method for enhancing the biological denitrification process driven by sludge fermentation based on ultra-high-speed in-situ enrichment of anammox bacteria. The only difference from Example 1 is that no biological carrier is added. The specific operation steps are as follows: Select Figure 1 The SFBNR process shown in the figure comprises a NF-SBR 2 with effective volumes of 8 L, 8 L, 4 L, and 1 L, a SIFD-CSTR 3, a secondary sedimentation tank 6, and a sludge tank 9 (such as Figure 1 ); Among them, the wastewater in the water tank 1 is domestic sewage, and its main components are: NH4 + 40mg / L, NO2 - 1mg / L, NO3 - 1mg / L, and intermittently introduced into NF-SBR; the inoculated sludge of NF-SBR and SIFD-CSTR, the exogenous WAS of sludge tank 9 are taken from the actual secondary sedimentation tank of the sewage treatment plant, and the sludge particle size is 245-288um. In addition, the MLSS and MLVSS of the sludge in NF-SBR and SIFD-CSTR are 8.9g / L and 4.1g / L respectively; each cycle of NF-SBR is 8h, including 5 stages: 40min of water inlet, 1-3h of aeration, 40min of sedimentation, 40min of drainage, and at the beginning of each cycle, 3L of wastewater from inlet bucket 1 is pumped into the reactor (i.e., 50% exchange ratio). In addition, during the aeration stage, air is introduced into NF-SBR through air pump 7 and aeration plate 8; the reactor temperature of SIFD-CSTR is 35℃, the initial HRT is 16h, and cement mixing is continuously carried out through agitator 5. In addition, the effluent of SIFD-CSTR3 continuously enters the secondary sedimentation tank 6 , the sludge in the secondary sedimentation tank 6 continuously flows back to SIFD-CSTR3 , and SIFD-CSTR3 continuously receives the sludge in the sludge tank 9 .

[0073] The ultra-high-speed in-situ enrichment method of anammox bacteria in this comparative example comprises the following steps:

[0074] (1) Start the SFBNR process for 30 days, NH4 + The conversion rate reaches 95%, and the effluent NH4 + 、NO2 - 、NO3 - 2mg / L, 1mg / L, and 38mg / L respectively. SIFD-CSTR effluent NH4 + 、NO2 - 、NO3 - 、DNE、SRE、NH4 +The removal rates were 20.9 mg / L, 1 mg / L, 5.7 mg / L, 85%, 40%, and 5%, respectively. The relative abundances of JABWBG01sp013360575 and AnAOB in suspended sludge were 3% and 0%, respectively, and the TPMs of Hyd, key enzymes for carbon fixation, and enzymes related to cell component synthesis were all 0. The absolute abundance of AnAOB in suspended sludge was 0 copies / gVSS. The HRT was increased to 32h.

[0075] (2) On the 90th day, NH4 + The conversion rate reaches 95%, and the effluent NH4 + 、NO2 - 、NO3 - 2mg / L, 1mg / L, and 38mg / L respectively. SIFD-CSTR effluent NH4 + 、NO2 - 、NO3 - 、DNE、SRE、NH4 + The removal rates were 17.6 mg / L, 1 mg / L, 4.56 mg / L, 88%, 55%, and 20%, respectively. The relative abundances of JABWBG01 sp013360575 and AnAOB in suspended sludge increased to 6% and 1%, respectively, and the TPMs of Hyd, key enzymes for carbon fixation, and enzymes related to cell component synthesis increased to 0.0041, 0.0019, and 0.0751, respectively. The absolute abundance of AnAOB in suspended sludge was 1.57*10 9 copies / gVSS. Reduce HRT to 12h.

[0076] (3) On the 150th day, NH4 + The conversion rate reaches 95%, and the effluent NH4 + 、NO2 - 、NO3 - 2mg / L, 1mg / L, and 38mg / L respectively. SIFD-CSTR effluent NH4 + 、NO2 - 、NO3 - 、DNE、SRE、NH4 + The removal rates were 16.5 mg / L, 1 mg / L, 4.56 mg / L, 88%, 60%, and 25%, respectively. The relative abundances of JABWBG01 sp013360575 and AnAOB in suspended sludge increased to 17% and 2%, respectively, and the TPMs of Hyd, key enzymes for carbon fixation, and enzymes related to cell component synthesis increased to 0.0095, 0.0037, and 0.0976, respectively. The absolute abundance of AnAOB in suspended sludge increased from 1.04*10 10The absolute abundance and relative abundance of AnAOB in suspended sludge were only 1 / 10 and 1% of those in Example 1, respectively, indicating that the in-situ enrichment of AnAOB was slow, resulting in NH4 + The removal effect is poor, which is not conducive to optimizing the overall denitrification effect of the process.

[0077] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A method for intensifying a sludge fermentation-driven biological denitrification process based on ultra-high-speed in-situ enrichment of anammox bacteria, characterized in that: In the in-situ fermentation-denitrification continuous stirred reactor of the sludge fermentation coupled biological denitrification process, a hydrogen-producing functional strain, namely JABWBG01 sp013360575, was cultivated in a directed manner through the following steps: (1) Initial operation stage: The hydraulic retention time was maintained at 14-18 h, and the reactor was operated until the denitrification efficiency reached 80%-85%, and the sludge reduction rate reached 35%-45%; the relative abundances of JABWBG01 sp013360575 and AnAOB in the suspended sludge were 2-5% and 0%, respectively, and the absolute abundance of AnAOB in the suspended sludge was 0 copies / gVSS; NH4 + The removal rate is 1% to 10%; (2) Carrier addition and HRT enhancement stage: biological carriers were added to the reactor to increase the hydraulic retention time to 30-34 h, so that the denitrification efficiency reached 85%-90% and the sludge reduction rate reached 45%-55%. The relative abundances of JABWBG01sp013360575 and AnAOB on the biofilm increased from 0% to 25%-30% and 7%-9%, respectively. The absolute abundance of AnAOB on the biofilm was 1.58*10 9 ~1.72*10 9 copies / gVSS; NH4 + The removal rate is 10% to 30%; (3) HRT reduction stage: reduce the hydraulic retention time to 12-14 h, operate until the denitrification efficiency reaches 90%-95%, and the sludge reduction rate reaches 65%-75%; the relative abundance of JABWBG01 sp013360575 and AnAOB on the biofilm increases to 60%-70% and 20%-24%, respectively, and the absolute abundance of AnAOB on the biofilm is 5.29*10 12 ~7.23*10 12 copies / gVSS; NH4 + The removal rate is 80% to 85%, indicating that the ultra-high-speed in-situ enrichment of AnAOB is completed and deep denitrification is achieved; The sludge fermentation-driven biological denitrification process includes a sequencing batch nitrification reactor, an in-situ fermentation-denitrification continuous stirring reactor, a sedimentation tank and a sludge tank; The AnAOB are anammox bacteria.

2. The method for intensifying the sludge fermentation-driven biological denitrification process based on ultra-high-speed in-situ enrichment of anammox bacteria according to claim 1, characterized in that: The inoculum sludge in the sequencing batch nitrification reactor and the in situ fermentation-denitrification continuous stirred reactor came from the secondary sedimentation tank of the sewage treatment plant, and the sludge particle size was 245-288um; the MLSS and MLVSS of the sludge in the sequencing batch nitrification reactor and the in situ fermentation-denitrification continuous stirred reactor were 6.5-15.6g / L and 2.9-7.8g / L, respectively.

3. The method for intensifying the sludge fermentation-driven biological denitrification process based on ultra-high-speed in-situ enrichment of anammox bacteria according to claim 1, characterized in that: The in-situ fermentation-denitrification continuous stirred reactor continuously receives the effluent from the sequencing batch nitrification reactor and the residual sludge in the sludge tank to achieve simultaneous denitrification and sludge fermentation.

4. The method for intensifying the sludge fermentation-driven biological denitrification process based on ultra-high-speed in-situ enrichment of anammox bacteria according to claim 1, characterized in that: The sludge fermentation-driven biological denitrification process also includes a secondary sedimentation tank, and the sludge in the secondary sedimentation tank is returned to the in-situ fermentation-denitrification continuous stirring reactor; the temperature in the in-situ fermentation-denitrification continuous stirring reactor is maintained at 33-35°C.

5. The method for intensifying the sludge fermentation-driven biological denitrification process based on ultra-high-speed in-situ enrichment of anammox bacteria according to claim 1, characterized in that: The bio-carrier is a hydrophilic polyurethane foam carrier; the porosity of the bio-carrier is ≥98%, and the specific surface area is ≥6000m 2 / m 3 .

6. The method for intensifying the sludge fermentation-driven biological denitrification process based on ultra-high-speed in-situ enrichment of anammox bacteria according to claim 1, characterized in that: The filling volume percentage of the biological carrier in the in-situ fermentation-denitrification continuous stirring reactor is 10%-20%.

7. The method for intensifying the sludge fermentation-driven biological denitrification process based on ultra-high-speed in-situ enrichment of anammox bacteria according to claim 1, characterized in that: The influent of the sequencing batch nitrification reactor comes from domestic sewage; the NH4 + The concentration is 40-80mg / L, NO2 - The concentration is 0.5-1.5mg / L, NO3 - The concentration is 0.5-1.5mg / L.

8. The method for intensifying the sludge fermentation-driven biological denitrification process based on ultra-high-speed in-situ enrichment of anammox bacteria according to claim 1, characterized in that: Each cycle of the sequencing batch nitrification reactor is 6 to 8 hours, including 5 stages: water inlet for 30 to 50 minutes, aeration for 1 to 3 hours, sedimentation for 30 to 50 minutes, drainage for 30 to 50 minutes, and the rest of the time is an idle stage; at the beginning of each cycle, water with an exchange ratio of 50vt% is pumped into the sequencing batch nitrification reactor.

9. The method for intensifying the sludge fermentation-driven biological denitrification process based on ultra-high-speed in-situ enrichment of anammox bacteria according to claim 1, characterized in that: In the biological denitrification process driven by sludge fermentation, the NH4 + The conversion rate reached 95%.

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