A sludge fermentation driven biological denitrification process strengthening method based on anammox bacteria super-high-speed in-situ enrichment

Abstract

The present application relates to the sewage treatment technical field, particularly to a kind of sludge fermentation driven biological denitrification process intensification method based on anammox bacteria ultra-high speed in-situ enrichment.The present application is aimed at sludge fermentation driven biological denitrification (SFBNR) process, through the operation strategy of " short-term HRT promotion + biological carrier dosing", in the in-situ fermentation-denitrification continuous stirred reactor (SIFD-CSTR) in the process, a kind of hydrogen-producing functional strain JABWBG01sp013360575 is cultivated directionally, high-energy H2 produced by the strain is used to expand the nitrogen metabolism electron pool of anaerobic ammonia oxidation bacteria (AnAOB), to accelerate carbon sequestration and its driven cell component synthesis, realize AnAOB ultra-high speed in-situ enrichment, to promote the effluent NH4 + Efficient removal, thereby optimizing the overall denitrification effect of SFBNR process.

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment technology, and in particular to an enhanced method for sludge fermentation-driven biological denitrification process based on the ultra-high-speed in-situ enrichment of anammox bacteria. Background Technology

[0002] Excessive nitrogen emissions severely harm water bodies and human health. Most wastewater treatment plants rely on traditional nitrification-denitrification processes for nitrogen removal. However, this process presents significant sustainability challenges due to the large external carbon sources required for denitrification and the high cost and carbon footprint of waste sludge (WAS) treatment. Since organic carbon sources can be generated during WAS fermentation, sludge fermentation-driven biological nitrogen removal (SFBNR) offers a sustainable alternative for nitrogen removal. However, NH4 derived from fermentation... + The frequent exceedance of emission standards hinders the widespread adoption of this technology. Anammox (anaerobic ammonia oxidation) is an emerging, cost-effective, and efficient technology that can reduce NH4+ emissions. + and denitrification intermediate NO2 - The nitrogen is converted to nitrogen (N2). In the laboratory-scale SFBNR process, external anaerobic ammonia-oxidizing bacteria (AnAOB) are inoculated to remove NH4 from the fermentation wastewater. + The feasibility of this approach has been verified. However, the availability and adaptability of these external AnAOBs are limited. Therefore, developing an in-situ ultra-high-speed enrichment strategy for AnAOBs is crucial for the sustainable application of the SFBNR process. Summary of the Invention

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

[0004] To achieve the above objectives, the present invention provides the following solution:

[0005] This invention provides a method for enhancing a sludge fermentation-driven biological denitrification process based on ultra-high-speed in-situ enrichment of anammox bacteria. In a sludge fermentation coupled with biological denitrification (SFBNR) process within a continuous stirred reactor (SIFD-CSTR) for in-situ fermentation-denitrification, a hydrogen-producing functional bacterial strain, JABWBG01 sp013360575, is directionally cultivated through the following steps. (The high-energy H2 produced by this strain can significantly amplify the nitrogen metabolism electron pool of anammox bacteria (AnAOB), thereby accelerating carbon fixation and its driven cellular component synthesis, fundamentally achieving ultra-high-speed in-situ enrichment of AnAOB to significantly improve the denitrification efficiency of the SFBNR process.)

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

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

[0008] (3) HRT reduction stage: Reduce the hydraulic retention time to 12-14 hours, and 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 of 80% to 85% marks the completion of the ultra-high-speed in-situ enrichment of AnAOB and the achievement of deep denitrification.

[0009] The sludge fermentation-driven biological denitrification process includes a sequencing batch reactor (SBR), an in-situ fermentation-denitrification continuous stirred reactor, a sedimentation tank, and a sludge tank.

[0010] In this invention, suspended sludge refers to the sludge throughout the entire SIFD-CSTR reactor. The sludge in the SIFD-CSTR reactor is in a suspended state. After the subsequent addition of a biological carrier, the sludge in the SIFD-CSTR reactor will exist in both suspended and biofilm forms. Therefore, during the initial operation phase, suspended sludge is used to refer to the sludge in the reactor. This suspended sludge includes the inoculum sludge of the reactor and the added WAS from the sludge tank. Both the inoculum sludge and the added WAS come from the secondary sedimentation tank of the wastewater treatment plant, and the sludge particle size is 245–288 μm; the MLSS and MLVSS of the sludge in the sequencing batch reactor (SBR) and the in-situ fermentation-denitrification continuous stirred reactor are 6.5–15.6 g / L and 2.9–7.8 g / L, respectively.

[0011] In this invention, the in-situ fermentation-denitrification continuous stirred reactor continuously receives the effluent from the sequencing batch nitrification reactor and the residual sludge from the sludge tank, thereby achieving simultaneous denitrification and sludge fermentation.

[0012] In this invention, the sludge fermentation-driven biological denitrification process further includes a secondary sedimentation tank, in which the sludge 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 this invention, the biological carrier is a hydrophilic polyurethane foam carrier; the biological carrier has a dense porous structure with a porosity ≥98% and a specific surface area ≥6000 m². 2 / m 3 .

[0014] In this invention, the biocarrier is filled with 12.5% ​​of the volume in the in-situ fermentation-denitrification continuous stirred reactor. The biocarrier is used for the in-situ enrichment of AnAOB.

[0015] In this invention, the influent to the sequencing batch reactor (SBR) is domestic sewage; the NH4 in the domestic sewage... + Concentration of 40-80 mg / L, NO2 - The concentration is 1 mg / L, NO3 - The concentration is 1 mg / L.

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

[0017] In this invention, in the sludge fermentation-driven biological denitrification process, the NH4 in the sequencing batch reactor... +With a conversion rate of 95%, it can provide sufficient NO3 for SIFD-CSTR. - .

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

[0019] This invention focuses on SIFD-CSTR in the SFBNR process. By temporarily increasing and then decreasing the HRT (Heat Retention Time) while simultaneously adding a biological carrier (single-module moving bed biofilm module), it is possible to achieve highly efficient enrichment of the hydrogen-producing functional bacteria, JABWBG01sp013360575, in the reactor. Furthermore, the high-energy H2 produced by this bacteria can amplify the electron pool of AnAOB nitrogen metabolism, thereby accelerating carbon fixation and its driven cellular component synthesis, fundamentally achieving ultra-high-speed in-situ enrichment of AnAOB, thus promoting the production of effluent NH4 derived from fermentation. + This reduction makes sustainable nitrogen removal possible for the SFBNR process. Experiments have demonstrated that this method is effective for a biological nitrogen removal system driven by sludge fermentation and enhanced by ultra-high-speed in-situ enrichment of anammox bacteria.

[0020] NH4 is produced during sludge fermentation and combined denitrification. + CO2, H2, NO2 - Based on this, increasing and decreasing HRT can be used to cultivate a hydrogen-producing functional bacterial strain, JABWBG01 sp013360575, in the reactor. The high-energy H2 produced by this strain can be used to amplify the electron pool of AnAOB nitrogen metabolism, thereby promoting the ultra-high-speed in-situ enrichment of AnAOB.

[0021] The ultra-high-speed in-situ enrichment of AnAOB avoids the inoculation of exogenous AnAOB sludge and is used for NO2. - The addition of a dedicated reactor required for production, and the fact that in-situ enriched AnAOB is more adaptable to the existing process environment, contribute to the stable operation of SIFD-CSTR.

[0022] In-situ enrichment of AnAOB can remove NH4, an intermediate product of sludge fermentation and denitrification. + NO2 - This promotes sludge reduction and denitrification from the perspective of substrate removal. In addition, since denitrification is driven by sludge fermentation, the improvement in sludge reduction will further promote denitrification, thereby optimizing the overall nitrogen removal effect of SIFD-CSTR. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 A schematic diagram of a sludge fermentation coupled with biological denitrification process: 1. Inlet tank; 2. NF-SBR; 3. SIFD-CSTR; 4. Biological carrier; 5. Agitator; 6. Secondary sedimentation tank; 7. Air pump; 8. Aeration disc; 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 The TPM of hydrogen-producing enzymes, key carbon fixation enzymes, and cell component synthesis-related enzymes in the SIFD-CSTR reactor in Example 1, as well as the changing trends of the TPM of each cell component synthesis-related enzyme. Detailed Implementation

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

[0029] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Any stated value or intermediate value within a stated range, as well as each smaller range between any other stated value or intermediate value within said range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0030] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0031] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be apparent to those skilled in the art. This specification and embodiments are merely exemplary.

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

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

[0034] Electron-generating 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 the remaining sludge into CO2 and NH4. + H2 and reducing equivalents, and the latter can promote NO2 in denitrification. -The SFBNR process possesses the ability to provide the basic substrate environment required for AnAOB growth. Simultaneously, niche management strategies, such as integrating biocarriers into flocs, can enhance AnAOB retention and toxicity while minimizing direct competition with heterotrophic organisms, thus ensuring in-situ enrichment of AnAOB on the biofilm. Therefore, numerous studies have focused on achieving in-situ enrichment of AnAOB in the SFBNR process through the addition of biocarriers. However, the enrichment rate under this method remains very slow, as illustrated by the full-scale A2O process (1.4 × 10⁻⁶) published in *Water Research*, titled "Quantify the contribution of anammox for enhanced nitrogen removal through metagenomic analysis and mass balance in ananoxic moving bed biofilm reactor." 5 m 3 For example, after 600 days of operation, the relative abundance and absolute abundance of AnAOB in the biofilm were only 14.45% and 4 × 10⁻⁶, respectively. 8 copies / g VSS.

[0040] Studies have found that the nitrogen metabolism electron pool is established solely by reactions 3-4, and provides only a portion of the electron donors for reactions 1-2, leading to a shortage of electron donors required for efficient carbon fixation. Therefore, supplying a large amount of exogenous electron donors to expand the capacity of the nitrogen metabolism electron pool is key to accelerating the in-situ enrichment of AnAOB. ​​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 capabilities will exhibit 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) during fermentation can respectively promote the enrichment of hydrogen-producing bacteria such as JABWBG01 sp013360575 and wash away methanogenic bacteria, thereby enhancing H2 production and reducing H2 methanogenesis. Therefore, in the SFBNR process, HRT regulation will be beneficial for the targeted cultivation of JABWBG01 sp013360575, based on the high concentration of H2 produced by this strain to accelerate the in-situ enrichment of AnAOB.

[0041] Based on this, this study focuses on the SFBNR process, which consists of a sequencing batch reactor (NF-SBR), an in-situ fermentation-denitrification continuous stirred reactor (SIFD-CSTR), a sedimentation tank, and a sludge tank. Addressing the removal problem of fermentation-derived NH4+ in the SIFD-CSTR, a sludge fermentation-driven biological denitrification process enhancement method based on ultra-high-speed in-situ enrichment by anammox bacteria, namely "HRT regulation + biological carrier addition," is developed. This is crucial for enhancing process denitrification and achieving sustainable application.

[0042] This invention provides a method for enhancing a sludge fermentation-driven biological nitrogen removal process based on ultra-high-speed in-situ enrichment of anammox bacteria. This method targets the sludge fermentation-driven biological nitrogen removal (SFBNR) process. Through a "short-term HRT enhancement + biological carrier addition" operation strategy, a hydrogen-producing functional bacterium, JABWBG01 sp013360575, is directionally cultivated in the in-situ fermentation-denitrification continuous stirred reactor (SIFD-CSTR) of this process. The high-energy H2 produced by this bacterium amplifies the nitrogen metabolism electron pool of anaerobic ammonia-oxidizing bacteria (AnAOB), thereby accelerating carbon fixation and its driven cellular component synthesis, achieving ultra-high-speed in-situ enrichment of AnAOB, and promoting the production of effluent NH4 derived from fermentation. + Highly efficient removal, thereby optimizing the overall denitrification effect of the SFBNR process.

[0043] This invention is based on a constructed sludge fermentation coupled with biological nitrogen removal (SFBNR) process. In the in-situ fermentation-denitrification continuous stirred reactor (SIFD-CSTR) of this process, a hydrogen-producing functional bacterial strain, JABWBG01 sp013360575, is directionally cultivated through the following steps. The high-energy H2 produced by this strain can significantly amplify the nitrogen metabolism electron pool of anammox bacteria (AnAOB), thereby accelerating carbon fixation and its driven cellular component synthesis, fundamentally achieving ultra-high-speed in-situ enrichment of AnAOB, thus significantly improving the nitrogen removal efficiency of the SFBNR process. The specific steps are as follows:

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

[0045] (2) Carrier addition and HRT enhancement stage: Biological carriers were added to the reactor to enhance the HRT to 30–34 h, resulting in DNE reaching approximately 85%–90% and SRE reaching 45%–55%. The relative abundances of JABWBG01 sp013360575 and AnAOB on the biofilm increased from 0% to 25%–30% and 7%–9%, ​​respectively. Furthermore, the TPM of Hyd, FDH, CODH, and cell component synthesis-related enzymes 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 × 10⁻⁶. 9 ~1.72*10 9 copies / gVSS. NH4 + The removal rate is 10% to 30%.

[0046] (3) HRT reduction phase: HRT was reduced to 12-14 h, and DNE reached 90%-95%, 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, CODH, and cell component synthesis-related enzymes 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 of 80% to 85% marks the completion of the ultra-high-speed in-situ enrichment of AnAOB and the achievement of deep denitrification.

[0047] The hydrogen-producing enzyme (Hyd) is used to produce H2; the key carbon-fixing enzymes 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 terms used in this invention have the following meanings:

[0049] MLSS: Liquid-suspended solids concentration

[0050] MLVSS: Volatile Suspended Solids Concentration in Mixture

[0051] Unless otherwise specified, the technical solutions described in this invention are all conventional solutions in the field, and the reagents or raw materials used are all purchased from commercial channels or are publicly available unless otherwise specified.

[0052] In this embodiment of the invention, sludge samples were collected from SIFD-CSTR and then centrifuged at 5000 rpm for 15 minutes at 4°C using a high-speed centrifuge. After centrifugation, the supernatant was discarded. The resulting sludge samples were then exposed to liquid nitrogen for 10 minutes. The frozen samples were transported to a biotesting company using dry ice for molecular biology (high-throughput qPCR chip detection, metagenomic detection + metagenomic binning analysis) sequencing analysis. High-throughput qPCR chip detection was used to determine the absolute abundance of AnAOB in the samples, while metagenomic detection + metagenomic binning analysis was used to determine the relative abundance of JABWBG01 sp013360575 and AnAOB, as well as the relative abundance of genes encoding hydrogenase (Hyd), key carbon fixation enzymes, and cell component synthesis-related enzymes, i.e., TPM. Molecular biology detection showed enrichment of JABWBG01 sp013360575 bacteria.

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

[0054] Example 1

[0055] This embodiment provides an enhanced method for sludge fermentation-driven biological denitrification process based on the ultra-high-speed in-situ enrichment of Anammox bacteria, using methods such as... Figure 1 The SFBNR process shown includes NF-SBR2 (8L), SIFD-CSTR3 (8L), secondary sedimentation tank 6, and sludge tank 9 (with effective volumes of 8L, 8L, 4L, and 1L respectively). Figure 1 ); Among them, the wastewater in inlet tank 1 is domestic sewage, the main component of which is: NH4 + 40 mg / L, NO2 - 1 mg / L, NO3 -The concentration of wastewater in the NF-SBR was 1 mg / L, and it was intermittently introduced into the NF-SBR. The inoculum sludge and exogenous WAS in sludge tank 9 for both the NF-SBR and SIFD-CSTR were taken from the secondary sedimentation tank of an actual wastewater treatment plant, and the sludge particle size was 245–288 μm. Furthermore, the MLSS and MLVSS of the sludge in the NF-SBR and SIFD-CSTR were 8.9 g / L and 4.1 g / L, respectively. Each cycle of the NF-SBR was 8 hours, including 5 stages: 40 min of influent, 1–3 h of aeration, 40 min of sedimentation, 40 min of effluent discharge, and the remaining time was a resting stage. At the beginning of each cycle, 3 L of wastewater from influent tank 1 (i.e., a 50% exchange ratio) was pumped into the reactor. In addition, during the aeration stage, air was introduced into the NF-SBR through air pump 7 and aeration disc 8. The reactor temperature of the SIFD-CSTR was 35°C, the initial HRT was 16 h, and cement mixing was continuously carried out using agitator 5. In addition, the effluent from SIFD-CSTR3 continuously enters the secondary sedimentation tank 6, the sludge from the secondary sedimentation tank 6 is continuously returned to SIFD-CSTR3, and SIFD-CSTR3 continuously receives sludge from the sludge tank 9.

[0056] This embodiment is based on an enhanced biological denitrification process driven by sludge fermentation through ultra-high-speed in-situ enrichment of anammox bacteria, and includes the following steps:

[0057] (1) Start the SFBNR process for 30 days, and the NH4 of NF-SBR + Conversion rate reaches 95%, effluent NH4 + NO2 - NO3 - The NH4+ levels in the effluent from the SIFD-CSTR reached 2 mg / L, 1 mg / L, and 38 mg / L, respectively. + NO2 - NO3 - DNE, SRE, NH4 + The removal rates reached 20.9 mg / L, 1 mg / L, 5.7 mg / L, 85%, 40%, and 5%, respectively. Molecular biological tests revealed that the relative abundances of JABWBG01 sp013360575 and AnAOB in the suspended sludge on day 30 were 3% and 0%, respectively. Furthermore, the relative abundance (TPM) of the encoding genes for hydrogen-producing enzymes (Hyd) in JABWBG01 sp013360575, key carbon-fixing enzymes (formate dehydrogenase (FDH) and CO dehydrogenase (CODH)) in AnAOB, and enzymes related to cell component synthesis were all 0. The absolute abundance of AnAOB in the 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 m². 2 / m 3 Furthermore, the HRT was increased to 32 hours.

[0058] (2) On day 90, NH4 of NF-SBR + Conversion rate reaches 95%, effluent NH4 + NO2 - NO3 - The NH4+ levels in the effluent from the SIFD-CSTR reached 2 mg / L, 1 mg / L, and 38 mg / L, respectively. + NO2 - NO3 - DNE, SRE, NH4 + The removal rates reached 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 AnAOB belongs to the genus Candidatus Brocadia. Figure 3 The total phosphorus concentrations (TPMs) of Hyd, key carbon fixation enzymes, and cellular component synthesis-related enzymes increased to 0.01, 0.0033, and 0.1001, respectively. Figure 4 The absolute abundance of AnAOB on the biofilm was 1.58 × 10⁻⁶. 9 copies / gVSS. Reduce HRT to 12h.

[0059] (3) On day 150, NH4 of NF-SBR + Conversion rate reaches 95%, effluent NH4 + NO2 - NO3 - The NH4+ levels in the effluent from the SIFD-CSTR reached 2 mg / L, 1 mg / L, and 38 mg / L, respectively. + NO2 - NO3 - DNE, SRE, NH4 + The removal rates reached 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 TPM of Hyd, key carbon fixation enzymes, and cellular component synthesis-related enzymes increased to 0.1014, 0.0275, and 0.9264, respectively. The absolute abundance of AnAOB on the biofilm was 5.29 × 10⁻⁶. 12 copies / gVSS. Furthermore, the relative and absolute abundance of AnAOB on the biofilm increased at a rate higher than that of the aforementioned full-scale A2O process (1.4 × 10⁻⁶ copies / gVSS). 5 m 3The concentrations increased by 4.54 times and 52,900 times respectively, indicating that AnAOB achieved ultra-high-speed in-situ enrichment, thereby promoting NH4+. + It achieves efficient removal and optimizes the overall denitrification effect of the process.

[0060] Example 2

[0061] This embodiment provides an enhanced method for sludge fermentation-driven biological denitrification process based on the ultra-high-speed in-situ enrichment of Anammox bacteria, using methods such as... Figure 1 The SFBNR process shown includes NF-SBR2 (8L), SIFD-CSTR3 (8L), secondary sedimentation tank 6, and sludge tank 9 (with effective volumes of 8L, 8L, 4L, and 1L respectively). Figure 1 ); Among them, the wastewater in inlet tank 1 is domestic sewage, the main component of which is: NH4 + 80 mg / L, NO2 - 1 mg / L, NO3 - The concentration of wastewater in the NF-SBR was 1 mg / L, and it was intermittently introduced into the NF-SBR. The inoculum sludge and exogenous WAS in sludge tank 9 for both the NF-SBR and SIFD-CSTR were taken from the secondary sedimentation tank of an actual wastewater treatment plant, and the sludge particle size was 245–288 μm. Furthermore, the MLSS and MLVSS of the sludge in the NF-SBR and SIFD-CSTR were 8.9 g / L and 4.1 g / L, respectively. Each cycle of the NF-SBR was 8 hours, comprising 5 stages: 40 min of influent, 1–3 h of aeration, 40 min of sedimentation, and 40 min of effluent discharge. At the beginning of each cycle, 3 L of wastewater from influent tank 1 (i.e., a 50% exchange ratio) was pumped into the reactor. During the aeration stage, air was introduced into the NF-SBR through air pump 7 and aeration disc 8. The reactor temperature of the SIFD-CSTR was 35°C, the initial HRT was 16 h, and cement mixing was continuously carried out using agitator 5. In addition, the effluent from SIFD-CSTR3 continuously enters the secondary sedimentation tank 6, the sludge from the secondary sedimentation tank 6 is continuously returned to SIFD-CSTR3, and SIFD-CSTR3 continuously receives sludge from the sludge tank 9.

[0062] This embodiment is based on an enhanced biological denitrification process driven by sludge fermentation through ultra-high-speed in-situ enrichment of anammox bacteria, and includes the following steps:

[0063] (1) Start the SFBNR process for 30 days, and the NH4 of NF-SBR + Conversion rate reaches 95%, effluent NH4 + NO2 - NO3 - The NH4+ levels in the effluent from the SIFD-CSTR reached 4 mg / L, 1 mg / L, and 76 mg / L, respectively. + NO2 - NO3 -DNE, SRE, NH4 + The removal rates reached 22.8 mg / L, 1 mg / L, 15.2 mg / L, 80%, 40%, and 5%, respectively. The relative abundances of JABWBG01sp013360575 and AnAOB in the suspended sludge were 3% and 0%, respectively, and the total phosphorus concentrations (TPMs) of Hyd, key carbon fixation enzymes, and cell component synthesis-related enzymes were all 0. The absolute abundance of AnAOB in the 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 m². 2 / m 3 Furthermore, the HRT was increased to 32 hours.

[0064] (2) On day 90, NH4 of NF-SBR + Conversion rate reaches 95%, effluent NH4 + NO2 - NO3 - The NH4+ levels in the effluent from the SIFD-CSTR reached 4 mg / L, 1 mg / L, and 76 mg / L, respectively. + NO2 - NO3 - DNE, SRE, NH4 + The removal rates reached 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 TPM of Hyd, key carbon fixation enzymes, and cellular component synthesis-related enzymes increased to 0.0146, 0.0055, and 0.2001, respectively. The absolute abundance of AnAOB on the biofilm was 1.72 × 10⁻⁶. 9 copies / gVSS. Reduce HRT to 12h.

[0065] (3) On day 150, NH4 of NF-SBR + Conversion rate reaches 95%, effluent NH4 + NO2 - NO3 - The NH4+ levels in the effluent from the SIFD-CSTR reached 4 mg / L, 1 mg / L, and 76 mg / L, respectively. + NO2 - NO3 - DNE, SRE, NH4 +The removal rates reached 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 TPM of Hyd, key carbon fixation enzymes, and cellular component synthesis-related enzymes increased to 0.1265, 0.0345, and 1.2911, respectively. The absolute abundance of AnAOB on the biofilm was 7.23 × 10⁻⁶. 12 copies / gVSS. Furthermore, the relative and absolute abundance of AnAOB on the biofilm increased at a rate higher than that of the aforementioned full-scale A2O process (1.4 × 10⁻⁶ copies / gVSS). 5 m 3 The concentrations increased by 5.64 times and 72,300 times respectively, indicating that AnAOB achieved ultra-high-speed in-situ enrichment, thereby promoting NH4+. + It achieves efficient removal and optimizes the overall denitrification effect of the process.

[0066] Comparative Example 1

[0067] This comparative example provides an enhanced method for sludge fermentation-driven biological denitrification based on the ultra-high-speed in-situ enrichment of anammox bacteria. The only difference from Example 1 is that HRT adjustment is not performed. Specifically, the following method is used: Figure 1 The SFBNR process shown includes NF-SBR2 (8L), SIFD-CSTR3 (8L), secondary sedimentation tank 6, and sludge tank 9 (with effective volumes of 8L, 8L, 4L, and 1L respectively). Figure 1 ); Among them, the wastewater in inlet tank 1 is domestic sewage, the main component of which is: NH4 + 40 mg / L, NO2 - 1 mg / L, NO3 - The concentration of wastewater in the NF-SBR was 1 mg / L, and it was intermittently introduced into the NF-SBR. The inoculum sludge and exogenous WAS in sludge tank 9 for both the NF-SBR and SIFD-CSTR were taken from the secondary sedimentation tank of an actual wastewater treatment plant, and the sludge particle size was 245–288 μm. Furthermore, the MLSS and MLVSS of the sludge in the NF-SBR and SIFD-CSTR were 8.9 g / L and 4.1 g / L, respectively. Each cycle of the NF-SBR was 8 hours, comprising 5 stages: 40 min of influent, 1–3 h of aeration, 40 min of sedimentation, and 40 min of effluent discharge. At the beginning of each cycle, 3 L of wastewater from influent tank 1 (i.e., a 50% exchange ratio) was pumped into the reactor. During the aeration stage, air was introduced into the NF-SBR through air pump 7 and aeration disc 8. The reactor temperature of the SIFD-CSTR was 35°C, the initial HRT was 16 h, and cement mixing was continuously carried out using agitator 5. In addition, the effluent from SIFD-CSTR3 continuously enters the secondary sedimentation tank 6, the sludge from the secondary sedimentation tank 6 is continuously returned to SIFD-CSTR3, and SIFD-CSTR3 continuously receives sludge from the sludge tank 9.

[0068] This comparative method for in situ enrichment of anammox bacteria includes the following steps:

[0069] (1) Start the SFBNR process for 30 days, and the NH4 of NF-SBR + Conversion rate reaches 95%, effluent NH4 + NO2 - NO3 - The NH4+ levels in the effluent from the SIFD-CSTR reached 2 mg / L, 1 mg / L, and 38 mg / L, respectively. + NO2 - NO3 - DNE, SRE, NH4 + The removal rates reached 20.9 mg / L, 1 mg / L, 5.7 mg / L, 85%, 40%, and 5%, respectively. The relative abundances of JABWBG01sp013360575 and AnAOB in the suspended sludge were 3% and 0%, respectively, and the relative abundances of the encoding genes for Hyd, key carbon fixation enzymes, and cell component synthesis-related enzymes (TPM) were all 0. The absolute abundance of AnAOB in the 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 m². 2 / m 3 .

[0070] (2) On day 150, NH4 of NF-SBR + Conversion rate reaches 95%, effluent NH4 + NO2 - NO3 - The NH4+ levels in the effluent from the SIFD-CSTR reached 2 mg / L, 1 mg / L, and 38 mg / L, respectively. + NO2 - NO3 - DNE, SRE, NH4 + The removal rates reached 18.7 mg / L, 1 mg / L, 5.7 mg / L, 85%, 45%, and 15%, respectively. During reactor operation, from day 0 to day 150, the relative abundances of JABWBG01sp013360575 and AnAOB on the biofilm increased to 6% and 4%, respectively, and the TPM of Hyd, key carbon fixation enzymes, and cell component synthesis-related enzymes increased to 0.0052, 0.0024, and 0.0892, respectively. The absolute abundance of AnAOB on the biofilm reached 3.04 × 10⁻⁴. 10 The absolute 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 rate of AnAOB was slow, leading to the limited accumulation of NH4+.+ The removal effect is not good, which is not conducive to optimizing the overall denitrification effect of the process.

[0071] Comparative Example 2

[0072] This comparative example provides an enhanced method for sludge fermentation-driven biological denitrification 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 includes NF-SBR2 (8L), SIFD-CSTR3 (8L), secondary sedimentation tank 6, and sludge tank 9 (with effective volumes of 8L, 8L, 4L, and 1L respectively). Figure 1 ); Among them, the wastewater in inlet tank 1 is domestic sewage, the main component of which is NH4+. + 40 mg / L, NO2 - 1 mg / L, NO3 - The concentration of wastewater in the NF-SBR was 1 mg / L, and it was intermittently introduced into the NF-SBR. The inoculum sludge and exogenous WAS in sludge tank 9 for both the NF-SBR and SIFD-CSTR were taken from the secondary sedimentation tank of an actual wastewater treatment plant, and the sludge particle size was 245–288 μm. Furthermore, the MLSS and MLVSS of the sludge in the NF-SBR and SIFD-CSTR were 8.9 g / L and 4.1 g / L, respectively. Each cycle of the NF-SBR was 8 hours, comprising 5 stages: 40 min of influent, 1–3 h of aeration, 40 min of sedimentation, and 40 min of effluent discharge. At the beginning of each cycle, 3 L of wastewater from influent tank 1 (i.e., a 50% exchange ratio) was pumped into the reactor. During the aeration stage, air was introduced into the NF-SBR through air pump 7 and aeration disc 8. The reactor temperature of the SIFD-CSTR was 35°C, the initial HRT was 16 h, and cement mixing was continuously carried out using agitator 5. In addition, the effluent from SIFD-CSTR3 continuously enters the secondary sedimentation tank 6, the sludge from the secondary sedimentation tank 6 is continuously returned to SIFD-CSTR3, and SIFD-CSTR3 continuously receives sludge from the sludge tank 9.

[0073] This comparative method for ultra-high-speed in-situ enrichment of Anammox bacteria includes the following steps:

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

[0075] (2) On day 90, NH4 of NF-SBR + Conversion rate reaches 95%, effluent NH4 + NO2 - NO3 - The NH4+ levels in the effluent from the SIFD-CSTR reached 2 mg / L, 1 mg / L, and 38 mg / L, respectively. + NO2 - NO3 - DNE, SRE, NH4 + The removal rates reached 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 the suspended sludge increased to 6% and 1%, respectively, and the TPM of Hyd, key carbon fixation enzymes, and cell component synthesis-related enzymes increased to 0.0041, 0.0019, and 0.0751, respectively. The absolute abundance of AnAOB in the suspended sludge was 1.57 × 10⁻⁶. 9 copies / gVSS. Reduce HRT to 12h.

[0076] (3) On day 150, NH4 of NF-SBR + Conversion rate reaches 95%, effluent NH4 + NO2 - NO3 - The NH4+ levels in the effluent from the SIFD-CSTR reached 2 mg / L, 1 mg / L, and 38 mg / L, respectively. + NO2 - NO3 - DNE, SRE, NH4 + The removal rates reached 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 the suspended sludge increased to 17% and 2%, respectively, and the total phosphorus concentrations (TPMs) of Hyd, key carbon fixation enzymes, and cell component synthesis-related enzymes increased to 0.0095, 0.0037, and 0.0976, respectively. The absolute abundance of AnAOB in the suspended sludge increased from 1.04 × 10⁻⁶. 10The absolute and relative abundances of AnAOB in the suspended sludge were only 1 / 10 and 1 / 100 of those in Example 1, respectively, indicating that the in-situ enrichment rate of AnAOB was slow, leading to the slow accumulation of NH4+. + The removal effect is not good, which is not conducive to optimizing the overall denitrification effect of the process.

[0077] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A method for enhancing a sludge fermentation-driven biological denitrification process based on the ultra-high-speed in-situ enrichment of anammox bacteria, characterized in that, In an in-situ fermentation-denitrification continuous stirred reactor of a sludge fermentation coupled with biological denitrification process, a hydrogen-producing functional bacterial strain, JABWBG01 sp013360575, was directionally cultivated through the following steps: (1) Initial operation stage: Maintain a hydraulic retention time of 14~18h, and operate until the denitrification efficiency of the reactor reaches 80%~85% and the sludge reduction rate reaches 35%~45%; JABWBG01 sp013360575 in suspended sludge 、 The relative abundances of AnAOB were 2–5% and 0%, respectively, while the absolute abundance of AnAOB in suspended sludge was 0 copies / gVSS; NH4 + The removal rate is 1%~10%; (2) Carrier addition and HRT enhancement stage: Add biological carriers to the reactor to increase the hydraulic retention time to 30-34 hours, so that the denitrification efficiency reaches 85%-90% and the sludge reduction rate reaches 45%-55%; JABWBG01 sp013360575 on the biofilm 、 The relative abundance of AnAOB increased from 0% to 25%–30% and 7%–9%, ​​respectively, while the absolute abundance of AnAOB on biofilms was 1.58 × 10⁻⁶. 9 ~1.72*10 9 copies / gVSS; NH4 + The removal rate is 10%~30%; (3) HRT reduction stage: Reduce hydraulic retention time to 12-14h, operate until denitrification efficiency reaches 90%-95% and sludge reduction rate reaches 65%-75%; JABWBG01 sp013360575 on biofilm 、 The relative abundance of AnAOB increased to 60%–70% and 20%–24%, respectively, while the absolute abundance of AnAOB on biofilms was 5.29 × 10⁻⁶. 12 ~7.23*10 12 copies / gVSS; NH4 + The removal rate of 80%~85% marks the completion of the ultra-high-speed in-situ enrichment of AnAOB and the achievement of deep denitrification; The sludge fermentation-driven biological denitrification process includes a sequencing batch reactor, an in-situ fermentation-denitrification continuous stirred reactor, a sedimentation tank, and a sludge tank. The AnAOB refers to anammox bacteria; The inoculated sludge in the sequencing batch nitrification reactor and the in-situ fermentation-denitrification continuous stirred reactor comes from the secondary sedimentation tank of the wastewater treatment plant, and the sludge particle size is 245~288um. The in-situ fermentation-denitrification continuous stirred reactor continuously receives the effluent from the sequencing batch nitrification reactor and the excess sludge from the sludge tank, achieving simultaneous denitrification and sludge fermentation. The sludge fermentation-driven biological denitrification process also includes a secondary sedimentation tank, in which sludge is returned to an in-situ fermentation-denitrification continuous stirred reactor.

2. The method for enhancing the sludge fermentation-driven biological denitrification process based on the ultra-high-speed in-situ enrichment of anammox bacteria according to claim 1, characterized in that, The MLSS and MLVSS of sludge in the sequencing batch reactor and the in-situ fermentation-denitrification continuous stirred reactor were 6.5~15.6 g / L and 2.9~7.8 g / L, respectively.

3. The method for enhancing the sludge fermentation-driven biological denitrification process based on the ultra-high-speed in-situ enrichment of anammox bacteria according to claim 1, characterized in that, The temperature in the in-situ fermentation-denitrification continuous stirred reactor was maintained at 33~35℃.

4. The method for enhancing the sludge fermentation-driven biological denitrification process based on the ultra-high-speed in-situ enrichment of anammox bacteria according to claim 1, characterized in that, The biological carrier is a hydrophilic polyurethane foam carrier; the porosity of the biological carrier is ≥98%, and the specific surface area is ≥6000 m². 2 / m 3 .

5. The method for enhancing the sludge fermentation-driven biological denitrification process based on the ultra-high-speed in-situ enrichment of anammox bacteria according to claim 1, characterized in that, The biological carrier is filled in the in-situ fermentation-denitrification continuous stirred reactor at a volume percentage of 10%-20%.

6. The method for enhancing the sludge fermentation-driven biological denitrification process based on the ultra-high-speed in-situ enrichment of anammox bacteria according to claim 1, characterized in that, The influent to the sequencing batch reactor (SBR) is domestic sewage; the domestic sewage contains NH4+. + Concentration of 40-80 mg / L, NO2 - The concentration is 0.5-1.5 mg / L, NO3 - The concentration is 0.5-1.5 mg / L.

7. The method for enhancing the sludge fermentation-driven biological denitrification process based on the 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 6-8 hours, including 5 stages: influent 30-50 minutes, aeration 1-3 hours, sedimentation 30-50 minutes, drainage 30-50 minutes, and the remaining time is an idle stage; at the beginning of each cycle, influent with an exchange ratio of 50 VT% is pumped into the sequencing batch nitrification reactor.

8. The method for enhancing the sludge fermentation-driven biological denitrification process based on the ultra-high-speed in-situ enrichment of anammox bacteria according to claim 1, characterized in that, In sludge fermentation-driven biological nitrogen removal processes, the NH4+ in the sequencing batch reactor (SBR) is... + The conversion rate reached 95%.

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