Wastewater biological agents and their applications

Abstract

The present invention provides a sewage biological preparation and its application for treating high-ammonia-nitrogen, low-carbon-to-nitrogen ratio sewage. The preparation comprises, by weight, 10-20 parts of a direct ammonia-oxidizing bacteria mixture, 25-50 parts of zeolite, and 40-50 parts of a slow-release carbon source. The application of the sewage biological preparation in the present invention optimizes the microbial living environment and enhances microbial activity in the activated sludge, allowing the activated sludge to evolve into a functionally complex nitrifying-direct ammonia-oxidizing activated sludge. The sludge exhibits a dense morphology, excellent settling properties, and excellent stability and shock resistance, effectively addressing the technical issue of the impact of high ammonia-nitrogen environments on sludge performance in conventional technologies.

Description

Technical Field

[0001] The present invention relates to the field of sewage treatment, and in particular to a sewage biological preparation and application thereof. Background Art

[0002] Due to the complexity of sewage characteristics and the limitations of treatment technology, the treatment of wastewater with high ammonia nitrogen and low carbon ratio has always been a major difficulty in the field of sewage treatment.

[0003] The concentration of ammonia nitrogen in high-ammonia-nitrogen-low-carbon ratio wastewater is higher, and high concentrations of ammonia nitrogen are toxic to microorganisms in activated sludge, destroying the integrity of microbial cell membranes and causing leakage of internal cell substances, thereby affecting the normal metabolism and function of the cells and significantly reducing the activity of microorganisms. In contrast, filamentous bacteria have a certain tolerance to high ammonia nitrogen environments and can maintain their growth advantage in such environments. This growth trend tends to stimulate the proliferation and growth of filamentous bacteria in the sludge system. However, excessive growth of filamentous bacteria will change the structure of the sludge, making it loose and reducing its density, thereby affecting the sludge's settling performance. Excessive ammonia nitrogen loads can also lead to sludge disintegration, that is, the microorganisms and organic matter in the sludge are no longer tightly bound together, but are dispersed in the water. This disintegration phenomenon will further aggravate the swelling and thinning of the sludge.

[0004] To avoid the above problems, traditional biochemical treatment methods such as nitrification-denitrification process usually require a higher carbon-nitrogen ratio and a large amount of aeration to maintain microbial activity. Under low COD conditions, sludge cultivation is difficult, and excessive aeration can easily lead to sludge self-oxidation and dissolution, thereby affecting the sludge sedimentation performance. In addition, high ammonia nitrogen influent has an impact on the sludge system, which requires a long period of acclimation to adapt.

[0005] Based on the above, it is urgent to study a treatment method for high ammonia nitrogen and low carbon ratio wastewater to solve the above problems. Summary of the Invention

[0006] The main purpose of the present invention is to provide a sewage treatment method and bioreactor for direct ammonia oxidation coupled with autotrophic denitrification, so as to solve the technical problem of the impact of high ammonia nitrogen environment on sludge performance in the above-mentioned common technologies.

[0007] To achieve the above objectives, the present invention provides a sewage biological preparation for use in the treatment of high-ammonia-nitrogen and low-carbon-nitrogen ratio sewage. The biological preparation comprises, by mass, 10 to 20 parts of a direct ammonia-oxidizing bacteria mixture, 25 to 50 parts of zeolite, and 40 to 50 parts of a slow-release carbon source.

[0008] Furthermore, the composition of the direct ammonia oxidizing bacteria mixture includes direct ammonia oxidizing bacteria, extracellular polymers, inert inorganic matter and a small amount of miscellaneous bacteria.

[0009] Furthermore, the high-ammonia-nitrogen and low-carbon-nitrogen ratio sewage includes fertilizer production wastewater, MSG manufacturing wastewater, coking industry wastewater, landfill leachate, coal gas production wastewater and livestock and poultry breeding wastewater. The ammonia nitrogen content in the high-ammonia-nitrogen and low-carbon-nitrogen ratio sewage is 300-2000 mg / L, and the carbon-nitrogen ratio is less than 2.86.

[0010] Furthermore, the preparation of the direct ammonia oxidizing bacteria mixture comprises the steps of:

[0011] Inoculating activated sludge containing direct ammonia oxidizing bacteria into a reaction tank, introducing the high-ammonia-nitrogen, low-carbon-nitrogen ratio sewage into the reaction tank and adjusting the mass fraction of hydroxylamine therein to 0.005% to 1%, controlling the dissolved oxygen in the reaction tank to 2 to 5 mg / L, and setting the hydraulic retention time of the high-ammonia-nitrogen, low-carbon-nitrogen ratio sewage to 12 to 48 hours;

[0012] When the total nitrogen removal rate of the effluent is higher than 80%, the effluent mixture is centrifuged at a rotation speed of 6000-8000 r / min to obtain a solid product, which is the direct ammonia oxidizing bacteria mixture.

[0013] Furthermore, the direct ammonia oxidizing bacteria include one or more of Alcaligenes, Bacillus, Acinetobacter, Klebsiella, Pseudomonas and Rhodococcus.

[0014] Furthermore, the particle size of the zeolite is 50-100 μm, the slow-release carbon source includes one or more of peat, rice husk, straw, and degradable plastic, and the particle size of the slow-release carbon source is no more than 200 μm.

[0015] Furthermore, the sewage biological preparation also includes a binder, which includes one or more of gelatin, polyvinyl alcohol and / or sodium alginate, and the amount of the binder added is 2 to 5% of the total mass of the direct ammonia oxidizing bacteria mixture, the zeolite and the slow-release carbon source.

[0016] Furthermore, the preparation of the sewage biological preparation comprises the steps of:

[0017] The direct ammonia oxidizing bacteria mixture, the slow-release carbon source, the zeolite and the binder are mixed in proportion, extruded into granules and then subjected to low-temperature drying to obtain the sewage biological preparation, wherein the particle size of the sewage biological preparation is 0.5 to 3 mm.

[0018] The present invention provides an application of a sewage biological preparation as described in any one of the above items in a continuous flow reactor, comprising the steps of: adding the sewage biological preparation into an aerobic section for treating high-ammonia-nitrogen and low-carbon-nitrogen ratio sewage, controlling the dissolved oxygen content in the high-ammonia-nitrogen and low-carbon-nitrogen ratio sewage to 1-3 mg / L, and obtaining treated sewage after hydraulic retention for 18-36 hours.

[0019] Furthermore, the dosage of the sewage biological agent is 5 to 50% of the pool volume.

[0020] The beneficial effects of the present invention are as follows:

[0021] The present invention provides a sewage biological preparation, which is composed of a direct ammonia oxidizing bacteria mixture, zeolite, and a slow-release carbon source. The direct ammonia oxidizing bacteria mixture can convert ammonia nitrogen (NH4 + ) is directly converted into nitrogen (N2), and it has a high tolerance to ammonia nitrogen and can quickly adapt to high ammonia nitrogen environments. The addition of a slow-release carbon source effectively enhances the activity of direct ammonia oxidizing bacteria in low-carbon wastewater with a high ammonia nitrogen ratio. Direct ammonia oxidizing bacteria are in a dominant position in the competition with nitrifying bacteria, and the released carbon source can be directly utilized by direct ammonia oxidizing bacteria for denitrification. Zeolite has selective adsorption for ammonia nitrogen in wastewater, which can greatly accelerate the enrichment of ammonia nitrogen on the surface of microbial preparations, increase the contact between ammonia nitrogen and direct ammonia oxidizing bacteria, and greatly improve treatment efficiency.

[0022] Based on their overwhelming survival advantage, direct ammonia oxidizing bacteria proliferate rapidly and continuously desorb from sewage biological preparations into activated sludge; and with the metabolic degradation of ammonia nitrogen in sewage by direct ammonia oxidizing bacteria and the targeted adsorption of ammonia nitrogen by zeolite, the ammonia nitrogen concentration in the water body decreases, the living environment of microorganisms in activated sludge is optimized, and the activity is enhanced. Activated sludge evolves into functionally complex nitrification-direct ammonia oxidation activated sludge with dense morphology, good sedimentation performance, excellent stability and impact resistance, which effectively solves the technical problem of the impact of high ammonia nitrogen environment on sludge performance in commonly used technologies. 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 following briefly introduces the drawings required for use in the embodiments or the description of the prior art. 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 the structures shown in these drawings without paying any creative work.

[0024] Figure 1 It is a schematic diagram of the microscopic morphology of the sludge flocs formed in Example 2 of the present invention.

[0025] Figure 2 It is a schematic diagram of the microscopic morphology of the sludge flocs formed in Comparative Example 2 of the present invention.

[0026] Figure 3 Schematic diagram of the diversity of microbial analysis in Analysis Examples 1 to 3 of the present invention.

[0027] The realization of the objectives, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0028] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0029] It should be noted that all directional indications (such as up, down, etc.) in the embodiments of the present invention are only used to explain the relative position relationship, movement status, etc. between the various components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0030] In addition, the terms "first," "second," and so on, used in this disclosure are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, features specified as "first" or "second" may explicitly or implicitly include at least one of these features.

[0031] Moreover, the technical solutions between the various embodiments of the present invention may be combined with each other, but this must be based on the fact that ordinary technicians in this field can implement them. When the combination of technical solutions is mutually contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0032] The present invention provides a sewage biological preparation, which is applied to the treatment of high-ammonia-nitrogen and low-carbon-nitrogen ratio sewage. The biological preparation comprises, by weight, 10 to 20 parts of a direct ammonia-oxidizing bacteria mixture, 25 to 50 parts of zeolite, and 40 to 50 parts of a slow-release carbon source.

[0033] In some embodiments, high-ammonia-nitrogen, low-carbon-nitrogen ratio wastewater originates from a wide range of industrial processes, including fertilizer production, monosodium glutamate manufacturing, coking industry, landfill leachate, coal gas production, and livestock and poultry farming. These high-ammonia-nitrogen, low-carbon-nitrogen ratio wastewaters typically have high ammonia-nitrogen concentrations and relatively low organic matter content, with ammonia-nitrogen content of 300-2000 mg / L and a carbon-nitrogen ratio of less than 2.86.

[0034] The composition of the direct ammonia oxidizing bacteria mixture includes direct ammonia oxidizing bacteria, extracellular polymers, inert inorganic matter and a small amount of miscellaneous bacteria.

[0035] The preparation of the direct ammonia oxidizing bacteria mixture comprises the steps of:

[0036] S1. Inoculate activated sludge containing direct ammonia oxidizing bacteria into a reaction tank, introduce the high-ammonia-nitrogen, low-carbon-nitrogen ratio sewage containing 0.005% to 1% by mass of hydroxylamine into the reaction tank, control the dissolved oxygen in the reaction tank to 2 to 5 mg / L, and the hydraulic retention time of the high-ammonia-nitrogen, low-carbon-nitrogen ratio sewage is 12 to 48 hours.

[0037] In some embodiments, the mass fraction of hydroxylamine in the sewage may be 0.05% to 0.5%.

[0038] In some embodiments, the COD / ammonia nitrogen ratio can be adjusted to 10-20 by adding a carbon source before the wastewater enters the reaction tank.

[0039] Among them, direct ammonia oxidizing bacteria can include one or more of Alcaligenes, Bacillus, Acinetobacter, Klebsiella, Pseudomonas and Rhodococcus

[0040] The activated sludge sources of direct ammonia oxidizing bacteria are fertilizer production, MSG manufacturing, coking industry, landfill leachate, coal gas production and livestock and poultry breeding wastewater biochemical treatment systems.

[0041] S2. When the total nitrogen removal rate of the effluent is higher than 80%, the effluent mixture is centrifuged at a rotation speed of 6000 to 8000 r / min to obtain a solid product, which is the direct ammonia oxidizing bacteria mixture.

[0042] The present invention adopts an in-situ enrichment method to prepare a direct ammonia oxygen bacteria mixture with strong stability.

[0043] Zeolite selectively adsorbs ammonia nitrogen in wastewater. This, on the one hand, accelerates its accumulation on the surface of direct ammonia-oxidizing bacteria, increasing their contact with the bacteria and significantly improving treatment efficiency. Furthermore, the addition of zeolite adsorbs ammonia nitrogen from wastewater, thereby optimizing the habitat for microorganisms like nitrifying bacteria and reducing the inhibitory effect of high ammonia nitrogen on traditional nitrifying bacteria, achieving coordinated removal. For example, the zeolite particle size can be 50 to 100 μm.

[0044] Slow-release carbon sources include one or more of peat, rice husks, straw, and biodegradable plastics, which can be ball-milled and air-sorted to produce a powder with a particle size distribution below 200 μm. The addition of a slow-release carbon source effectively enhances the activity of direct ammonia-oxidizing bacteria in wastewater with a low carbon-to-nitrogen ratio. The released carbon source can be directly utilized by the bacteria for denitrification. The use of waste biodegradable plastic powder can also realize the resource utilization of solid waste.

[0045] In some embodiments, the sewage biological preparation further includes a binder, which includes one or more of gelatin, polyvinyl alcohol, and / or sodium alginate. The addition of the binder can consolidate the direct ammonia oxidizing bacteria mixture, zeolite, and slow-release carbon source, thereby achieving a tight bond between the three.

[0046] In other embodiments, the preparation of the sewage biological preparation comprises the steps of:

[0047] The direct ammonia oxidizing bacteria mixture, the slow-release carbon source, the zeolite and the binder are mixed in proportion, extruded into granules and then subjected to low-temperature drying to obtain the sewage biological preparation, wherein the particle size of the sewage biological preparation is 0.5 to 3 mm.

[0048] The present invention also provides an application of the sewage biological preparation as described in any one of the above items in sewage treatment, comprising the steps of: adding the sewage biological preparation into the aerobic section for treating high-ammonia-nitrogen and low-carbon-nitrogen ratio sewage, controlling the dissolved oxygen content in the high-ammonia-nitrogen and low-carbon-nitrogen ratio sewage to 1-3 mg / L, and obtaining treated sewage after hydraulic retention for 18-36 hours.

[0049] In some embodiments, when sewage biological agents are added to the aerobic section of high ammonia nitrogen and low carbon nitrogen ratio sewage treatment, the activated sludge concentration in the aerobic section can be 3000-5000 mg / L.

[0050] For example, the activated sludge in the aerobic section can be inoculated from the activated sludge in the similar high ammonia nitrogen and low carbon nitrogen ratio sewage biochemical system, or the sewage biological agent can be directly added to the aerobic section containing the activated sludge.

[0051] The settling properties of sludge are closely related to the activity of its microorganisms, primarily nitrifying bacteria. Activated sludge is amorphous flocs with a particle size of 200 to 1000 microns, similar to alum flowers, and exhibits excellent coagulation and settling properties. Active microorganisms typically exist in the form of flocs, which are viscous masses coated with polysaccharides secreted by bacteria. This provides the bacteria with resistance to adverse external factors and facilitates the settling and separation of the activated sludge.

[0052] High concentrations of ammonia nitrogen have an inhibitory effect on the activity of nitrifying bacteria, while direct ammonia oxidizing bacteria have a high tolerance to ammonia. Combined with the use of slow-release carbon sources, the competitiveness of direct ammonia oxidizing bacteria in the aerobic section is guaranteed, and direct ammonia oxidizing bacteria can achieve exclusive growth in high-ammonia nitrogen wastewater. Among commonly used technologies, the combination of anaerobic ammonium oxidation and aerobic / anaerobic digestion is considered to be an effective method for simultaneously removing organic matter and ammonia from high-ammonia nitrogen wastewater and recovering resources. However, excessive C / N ratios entering the anaerobic ammonium oxidation system will cause excessive growth of denitrifying bacteria, resulting in the inhibition of the anaerobic ammonium oxidation process and the failure of denitrification. Direct ammonia oxidation technology provides an alternative to the complex coupling process in the treatment of high-ammonia nitrogen wastewater, replacing it with a one-step aerobic process.

[0053] Based on their overwhelming survival advantage, direct ammonia oxidizing bacteria proliferate rapidly and continuously desorb from sewage biological preparations into activated sludge; and with the metabolic degradation of ammonia nitrogen in sewage by direct ammonia oxidizing bacteria and the targeted adsorption of ammonia nitrogen by zeolite, the ammonia nitrogen concentration in the water body decreases, the living environment of microorganisms in activated sludge is optimized, and the activity is enhanced. Activated sludge evolves into functionally complex nitrification-direct ammonia oxidation activated sludge with dense morphology, good sedimentation performance, excellent stability and impact resistance, which effectively solves the technical problem of the impact of high ammonia nitrogen environment on sludge performance in commonly used technologies.

[0054] And with the modification and evolution of activated sludge, this stable sludge system can maintain high treatment efficiency and stability in the treatment of high ammonia nitrogen and low carbon nitrogen ratio wastewater in the continuous flow reactor, reducing operational fluctuations; and this complex microbial community structure has strong impact resistance to water quality changes (such as pH value, toxic substances, etc.), and can maintain stable treatment effects to a certain extent.

[0055] In comparison, the direct ammonia oxidizing bacteria used in conventional technologies are heterotrophic. Current research focuses primarily on laboratory-scale treatment of high-carbon-nitrogen ratio wastewater. There are no reports on the enrichment and application of Dirammox microorganisms in continuous flow reactors. Inoculating direct ammonia oxidizing bacteria in high-carbon-nitrogen ratio wastewater inevitably faces problems such as poor retention and low abundance. However, the present invention, through the preparation of an immobilized bacterial agent, combines a slow-release carbon source, zeolite, and direct ammonia oxidizing bacteria into a direct ammonia oxidizing agent, achieving high abundance, long-term retention, and sludge modification of direct ammonia oxidizing bacteria in continuous flow wastewater.

[0056] The present invention simplifies the multi-stage treatment process in common technology into a single-process process, and the effluent water quality meets the standards and the effect is stable, successfully achieving simplified operation and management and improved flexibility.

[0057] In some embodiments, the dosage of the sewage biological agent is 5-50% of the tank capacity.

[0058] For easier understanding, the following examples are given:

[0059] Example 1 Preparation of direct ammonia oxidizing bacteria agent

[0060] Inoculating activated sludge from a biochemical treatment section of coal chemical wastewater containing direct ammonia oxidizing bacteria into a reaction tank, introducing coal gasification wastewater into the reaction tank and adjusting the mass fraction of hydroxylamine therein to 0.5%, adjusting the COD / ammonia nitrogen ratio of the wastewater to greater than 10 by adding a carbon source before entering the reaction tank, controlling the dissolved oxygen in the reaction tank to 2-5 mg / L, and setting the hydraulic retention time of the high-ammonia-nitrogen and low-carbon-nitrogen ratio wastewater to 24 hours;

[0061] When the total nitrogen removal rate of the effluent is higher than 80%, the effluent mixture is centrifuged at a rotation speed of 6000-8000 r / min, and the solid product is obtained, which is the direct ammonia oxidizing bacteria mixture.

[0062] A direct ammonia oxidizing bacteria mixture, zeolite and peat are mixed, with the mass proportions of the three being 25%, 35% and 40% respectively, mixed with a binder such as gelatin and sodium alginate, extruded into granules of 2 to 3 mm, and dried at low temperature to obtain a direct ammonia oxidizing bacteria agent.

[0063] Example 2 Continuous Flow Test

[0064] The influent of this embodiment is taken from the gasification effluent of a coal chemical industry. The influent ammonia nitrogen concentration is 390.4-559 mg / L, the influent COD is 400-941.9 mg / L, and the COD / ammonia nitrogen ratio is 1.87, which is a typical high ammonia nitrogen and low carbon nitrogen ratio influent.

[0065] The inoculum sludge was obtained from the aerobic terminal section of the biochemical reactor at the Tongmei Chemical Plant. The SBR reactor was started with an inoculum sludge concentration of 4000 mg / L. The SBR reactor achieves biochemical treatment of wastewater by completing the basic processes of water intake, aeration, sedimentation, drainage, and standby in a single reactor in a chronological order. The SBR process cycle includes water intake, aeration, sedimentation, drainage, and standby time. Based on the denitrification characteristics of direct ammonia-oxidizing bacteria, the multi-stage treatment process was simplified to a single-stage process, retaining only the aerobic section. The DO in this section was controlled at 2-3 mg / L. Specific operating parameters are shown in Table 1.

[0066] Table 1 Reactor initial operating parameters

[0067]

[0068] Comparative Example 1: Other parameters are consistent with Example 2, and the difference is that the zeolite in the direct ammonia oxidizer is replaced by sepiolite.

[0069] Comparative Example 2: Other parameters were consistent with Example 2, with the difference being that no direct ammonia oxidizing bacteria agent was added.

[0070] After stable operation, continuous sampling and tracking of ammonia nitrogen and total nitrogen in the inlet and outlet water were carried out, and sludge samples of Example 2 and Comparative Example 2 were simultaneously obtained for microscopic morphology detection. The results are shown in Table 1. Figure 1 and Figure 2 shown.

[0071] Table 2 Ammonia nitrogen and total nitrogen removal rate results of Example 2 and Comparative Examples 1-2

[0072] Ammonia nitrogen removal rate (%) Total nitrogen removal rate (%) Example 2 97.13％ 80.15％ Comparative Example 1 86.35％ 71.42％ Comparative Example 2 60.23％ 2.35％

[0073] As can be seen from Table 1, the direct ammonia oxidizing bacteria agent prepared by in-situ enriching the direct ammonia oxidizing bacteria mixture in the activated sludge of the biochemical pool in the plant area and combining it with a slow-release carbon source and zeolite can directly oxidize ammonia into dinitro gas or nitrogen in the aerobic section. The selective adsorption of ammonia nitrogen by zeolite makes its ammonia nitrogen removal efficiency better than the direct ammonia oxidizing bacteria agent prepared by sepiolite, and increases the collision probability between the substrate ammonia nitrogen and the direct ammonia oxidizing bacteria. In Comparative Example 2, no direct ammonia oxidizing bacteria agent was added, and direct ammonia oxidizing bacteria could not be enriched in the conventional activated sludge system. Nitrate nitrogen was converted from ammonia nitrogen only through the action of nitrifying bacteria, and nitrogen removal from the system was not achieved. Figure 1 and Figure 2 It can be seen that the sludge flocs in Comparative Example 2 are loose, and a large number of filamentous bacteria are exposed outside the flocs, while the sludge flocs in Example 2 are compact, with better flocculation and sedimentation properties, and can achieve efficient treatment of high ammonia nitrogen and low carbon nitrogen ratio sewage.

[0074] Analysis Example 1: Dosage of Hydroxylamine Compounds

[0075] In this example, inoculum sludge was taken from the aerobic terminal of a biochemical reactor at a sewage treatment plant. The SBR reactor was started with an inoculum sludge concentration of 500 mg / L and an MLVSS / MLSS ratio of 0.49. The SBR reactor achieves biochemical treatment of wastewater by completing the basic processes of water intake, aeration, sedimentation, drainage, and standby in a single reaction tank in a chronological order. The SBR process cycle includes water intake, aeration, sedimentation, drainage, and standby time.

[0076] To systematically evaluate the enrichment effect of hydroxylamine compounds on direct ammonia oxidizing bacteria, four SBR reactors were set up to simulate enrichment tanks for testing. A0 served as the blank group, with no hydroxylamine added; control group A1 was dosed with 0.002% hydroxylamine; experimental group A2 was dosed with 0.1% hydroxylamine; and control group A3 was dosed with 5% hydroxylamine. The influent for this experiment was simulated wastewater. Water quality indicators ranged from approximately: NH4 + -N: 50~70mg / L, COD: 400~600mg / L.

[0077] The initial operating parameter settings of the reactor are shown in Table 3. In the water inlet stage, a peristaltic pump is used for water inlet, and the water inlet time is 10 minutes. In the aerobic stage, a stirrer is used to drive the stirring paddle for stirring, and the stirring speed is 120rpm. The dissolved oxygen in the process is controlled at 2-5mg / L. In the sedimentation stage, this stage is a static stage, and the stirrer and aeration pump are not working during the process. In the decanting stage, a peristaltic pump is used to discharge water, and the decanter is lowered to the set height of the reactor to pump the clear liquid out of the reactor through the pump tube to complete the water discharge. After 7 cycles of stable operation, the sample was sent for detection of NH4 + -Microbial diversity in N, TN and mixed solutions.

[0078] Table 3 Reactor initial operating parameters

[0079]

[0080] From Table 4, we can see that the experimental group A2 has a strong effect on NH4 + The removal rates of -N were 99.45%, exceeding the 96.08%, 13.08%, and 95.82% of the control groups A1 and A3, respectively, and the blank group A0. The TN removal rate of experimental group A2 was 92.83%, while that of control group A1 was 10.67%. Control group A3 and the blank group A0 showed virtually no TN removal. TN is typically removed through denitrification under anoxic conditions, but A2 achieved efficient TN removal under aerobic conditions, indirectly indicating that microbial communities capable of direct ammonia oxidation were enriched within the system. However, due to the low hydroxylamine concentration in A1, other microbial species were not inhibited. The high hydroxylamine concentration in A3 resulted in the death of microorganisms within the system.

[0081] The microbial diversity analysis was performed on samples from each group. Figure 3 The circled mark is the abundance value of direct ammonia nitrogen bacteria Alcaligenes. Figure 3 It can be seen that the abundance of direct ammonia oxidizing bacteria Alcaligenes in the experimental group A2 increased from 0.023% of the blank group A0 to 60.307%, which was much higher than 0.191% of the control group A1 and 0.076% of A3.

[0082] Table 4 NH4 in water at different dosages of hydroxylamine compounds + -N and TN

[0083] A0 A1 A2 A3 <![CDATA[Effluent NH4 + N (mg / L)]]> 2.51 2.35 0.45 39.68 Outlet TN (mg / L) 58.8 53.6 4.6 59.13

[0084] Analysis Example 2: Hydroxylamine Compound Types

[0085] To systematically evaluate the enrichment effect of hydroxylamine compound types on direct ammonia-oxidizing bacteria, two SBR reactors were set up to simulate enrichment tanks. Hydroxylamine sulfate was added to reactor B1, and diethylhydroxylamine was added to reactor B2. The operating parameters in this example remained consistent with those of experimental group A2 in Example 1, except for the type of hydroxylamine compound.

[0086] The microbial diversity analysis was performed on samples from each group. Figure 3 .Depend on Figure 3 It can be seen that the abundance of direct ammonia oxidizing bacteria Alcaligenes in the B1 and B2 reactors increased from 0.023% of the blank group A0 to 53.819% and 78.963%, respectively, both achieving efficient enrichment of direct ammonia oxidizing bacteria.

[0087] Analysis Example 3: Influent COD / NH4+ -N

[0088] Evaluate influent COD / NH4 for the system + -N enrichment effect on direct ammonia oxidizing bacteria, two sets of SBR reactors were set up to simulate the enrichment tank for testing, and different ratios of COD / NH4 were configured by adjusting the COD content in the simulated wastewater. + -N influent, COD / NH4 of C1 influent + -N is 5; COD / NH4 of C2 influent + -N is 20. In this embodiment, the operating parameters are COD / NH4 + -N is inconsistent, and the other operating parameters are consistent with those of test group A2 in Example 1.

[0089] The microbial diversity analysis was performed on samples from each group. Figure 3 .Depend on Figure 3 It can be seen that the abundance of direct ammonia oxidizing bacteria Alcaligenes in the C1 reactor increased from 0.023% in the blank group A0 to 9.75%, which is much lower than 83.493% in C2. + -N can quickly increase the enrichment of direct ammonia oxidizing bacteria in the enrichment tank, thereby achieving stable supplementation of mainstream bacteria and stable aerobic ammonia oxidation denitrification of the mainstream system.

[0090] The above technical solutions of the present invention are only preferred embodiments of the present invention and do not limit the patent scope of the present invention. All equivalent structural transformations made by using the contents of the present invention's description and drawings under the technical concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. An application of a sewage biological preparation in a continuous flow reactor, characterized in that: The method comprises the following steps: adding a sewage biological agent into an aerobic section for treating high-ammonia-nitrogen and low-carbon-nitrogen ratio sewage, controlling the dissolved oxygen content in the high-ammonia-nitrogen and low-carbon-nitrogen ratio sewage to be 1-3 mg / L, and performing hydraulic retention for 18-36 hours to obtain treated sewage; wherein the activated sludge concentration in the aerobic section is 3000-5000 mg / L; The composition of the sewage biological preparation includes, by weight: 10 to 20 parts of a direct ammonia oxidizing bacteria mixture, 25 to 50 parts of zeolite, and 40 to 50 parts of a slow-release carbon source; The composition of the direct ammonia oxidizing bacteria mixture includes direct ammonia oxidizing bacteria, extracellular polymers, inert inorganic matter and a small amount of miscellaneous bacteria. The preparation of the direct ammonia oxidizing bacteria mixture includes the following steps: Inoculating activated sludge containing direct ammonia oxidizing bacteria into a reaction tank, introducing the high-ammonia-nitrogen and low-carbon-nitrogen ratio sewage into the reaction tank and adjusting the mass fraction of hydroxylamine therein to 0.005%-1%, and adjusting the COD / ammonia-nitrogen ratio of the sewage to 10-20 by adding a carbon source before entering the reaction tank; When the total nitrogen removal rate of the effluent is higher than 80%, the effluent mixture is centrifuged to obtain a solid product, which is the direct ammonia oxidizing bacteria mixture.

2. The use of the sewage biological preparation in a continuous flow reactor according to claim 1, characterized in that: The high-ammonia-nitrogen and low-carbon-nitrogen ratio sewage includes fertilizer production wastewater, MSG manufacturing wastewater, coking industry wastewater, landfill leachate, coal gas production wastewater and livestock and poultry breeding wastewater. The ammonia nitrogen content in the high-ammonia-nitrogen and low-carbon-nitrogen ratio sewage is 300~2000 mg / L, and the carbon-nitrogen ratio is less than 2.

86.

3. The use of the sewage biological preparation in a continuous flow reactor according to claim 1, characterized in that: The preparation of the direct ammonia oxidizing bacteria mixture comprises the steps of: Inoculating activated sludge containing direct ammonia oxidizing bacteria into a reaction tank, introducing the high-ammonia-nitrogen, low-carbon-nitrogen ratio sewage into the reaction tank and adjusting the mass fraction of hydroxylamine therein to 0.005% to 1%, controlling the dissolved oxygen in the reaction tank to 2 to 5 mg / L, and setting the hydraulic retention time of the high-ammonia-nitrogen, low-carbon-nitrogen ratio sewage to 12 to 48 hours; When the total nitrogen removal rate of the effluent is higher than 80%, the effluent mixture is centrifuged at a rotation speed of 6000-8000 r / min to obtain a solid product, which is the direct ammonia oxidizing bacteria mixture.

4. The use of the sewage biological preparation in a continuous flow reactor according to claim 3, characterized in that: The direct ammonia oxidizing bacteria include one or more of Alcaligenes, Bacillus, Acinetobacter, Klebsiella, Pseudomonas and Rhodococcus.

5. The use of the sewage biological preparation in a continuous flow reactor according to claim 1, characterized in that: The particle size of the zeolite is 50-100 μm, the slow-release carbon source includes one or more of peat, rice husk, straw, and degradable plastic, and the particle size of the slow-release carbon source is no more than 200 microns.

6. The use of the sewage biological preparation in a continuous flow reactor according to claim 5, characterized in that: The sewage biological preparation also includes a binder, which includes one or more of gelatin, polyvinyl alcohol and / or sodium alginate. The amount of the binder added is 2-5% of the total mass of the direct ammonia oxidizing bacteria mixture, the zeolite and the slow-release carbon source.

7. The use of the sewage biological preparation in a continuous flow reactor according to claim 6, characterized in that: The preparation of the sewage biological preparation comprises the steps of: The direct ammonia oxidizing bacteria mixture, the slow-release carbon source, the zeolite, and the binder are mixed in proportion, extruded into granules, and then subjected to low-temperature drying to obtain the sewage biological preparation, wherein the particle size of the sewage biological preparation is 0.5-3 mm.

8. The use of the sewage biological preparation in a continuous flow reactor according to claim 1, characterized in that: The dosage of the sewage biological agent is 5-50% of the pool capacity.

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