A method for constructing a short-cut denitrifying anammox filter

Abstract

The present invention provides a method for constructing a shortcut denitrification anaerobic ammonium oxidation filter. This method connects two biological filters in series and inoculates the activated sludge from a sewage treatment plant into both filters; controls the influent C / NO3 ‑ -N to be 3-6, enabling a shortcut denitrification reaction to occur in the first-stage biological filter to produce the substrate nitrite nitrogen, and the second-stage biological filter utilizes the effluent from the first-stage biological filter to enrich anaerobic ammonium oxidation bacteria. During the operation stage, based on the influent and effluent data in the second-stage biological filter, the influent ammonia nitrogen concentration is regulated, and the carbon source dosage is regulated to ensure that the first-stage biological filter produces sufficient nitrite nitrogen for supply to the second-stage biological filter. Throughout the process, anaerobic ammonium oxidation bacteria and shortcut denitrification bacteria are not inoculated. While meeting the effluent reaching the first-class A standard, anaerobic ammonium oxidation bacteria are gradually enriched in the second-stage biological filter, improving the total nitrogen removal efficiency and saving the carbon source, and based on the second-stage biological filter where anaerobic ammonium oxidation bacteria have been successfully enriched, shortcut denitrification bacteria are enriched, ultimately constructing a shortcut denitrification anaerobic ammonium oxidation filter.

Description

Technical Field

[0001] The present invention relates to a method for constructing a short-cut denitrification anaerobic ammonium oxidation filter, belonging to the field of sewage treatment. Background Art

[0002] The secondary effluent of sewage treatment plants generally has a high nitrate nitrogen content and is difficult to meet the Class-A standard. In order to remove the excessive nitrate nitrogen, a post-denitrification filter is usually installed. The denitrifying bacteria use organic matter as the carbon source to reduce nitrate to nitrogen gas, achieving deep nitrogen removal and meeting the Class-A standard. However, the biodegradable organic matter in the effluent of the secondary sedimentation tank is limited, and it is necessary to add an additional carbon source to the denitrification filter, which becomes a high cost for sewage treatment plants.

[0003] Anaerobic ammonium oxidation is a new low-carbon and energy-saving nitrogen removal technology. Anaerobic ammonium oxidation bacteria use ammonia nitrogen as the electron acceptor and nitrite as the electron donor to achieve autotrophic nitrogen removal without the participation of organic carbon sources. If the anaerobic ammonium oxidation technology can be applied to the denitrification filter, it can save the amount of carbon source added artificially and improve the total nitrogen removal efficiency.

[0004] The invention patent with the application number CN201810955099.9 discloses a denitrification filter nitrogen removal method for short-cut denitrification-anaerobic ammonium oxidation. This method directly inoculates anaerobic ammonium oxidation sludge and denitrifying sludge in the start-up stage of the denitrification filter, and adds a carbon source to the denitrification filter. The short-cut denitrification reaction and anaerobic ammonium oxidation reaction occur in the filter, and finally the deep nitrogen removal of the system is achieved. However, in practical applications, if you want to successfully construct a short-cut denitrification anaerobic ammonium oxidation filter, you will face three major problems: 1) If you directly inoculate anaerobic ammonium oxidation bacteria according to the above method, you need to purchase a large amount of mature anaerobic ammonium oxidation sludge, which is a huge investment; 2) If you directly enrich short-cut denitrifying bacteria and anaerobic ammonium oxidation bacteria in the denitrification biological filter at the same time, the anaerobic ammonium oxidation bacteria will not be able to compete with heterotrophic bacteria, resulting in limited abundance of anaerobic ammonium oxidation bacteria during the enrichment process, thus limiting the further improvement of the nitrogen removal effect; 3) If you enrich anaerobic ammonium oxidation bacteria by directly adding ammonia nitrogen and nitrite nitrogen, the added nitrite is also a significant expense. Summary of the Invention

[0005] Based on the above problems, the present invention in-situ enriches anaerobic ammonium oxidation bacteria without inoculating anaerobic ammonium oxidation seed sludge and short-cut denitrification seed sludge, and proposes a series of two-stage secondary biological filters, which only inoculate traditional activated sludge. By regulating the influent water quality, anaerobic ammonium oxidation bacteria are first self-enriched in the secondary biological filter, and then short-cut denitrifying bacteria are enriched, and finally a strategy for constructing an independent filter with short-cut denitrification anaerobic ammonium oxidation function is achieved.

[0006] The technical solution of the present invention is as follows:

[0007] A method for constructing a short-cut denitrifying anaerobic ammonium oxidation filter, comprising the following steps:

[0008] S1: Set up two biological filter reactors, namely a primary biological filter and a secondary biological filter, connect the two biological filters in series. Both the primary biological filter and the secondary biological filter use ceramsite filter media as fillers. The effluent of the primary biological filter serves as the influent of the secondary biological filter to construct a two-stage filter system;

[0009] S2: Membrane formation on the filler. Inoculate the traditional activated sludge from a sewage treatment plant into the primary biological filter and the secondary biological filter. Conduct the first-stage influent into the two-stage filter system, and control the concentrations of influent carbon source, nitrate nitrogen, and ammonia nitrogen so that the primary biological filter realizes the short-cut denitrification function.

[0010] A further technical solution is that in step S2, the ammonia nitrogen added in the first-stage influent is 2 - 5 mg / L, the nitrate nitrogen is 19 - 27 mg / L, and C / NO3 - is 3 - 6.

[0011] A further technical solution is that it further includes step S3: Conduct the second-stage influent into the two-stage filter system, control the concentrations of influent carbon source, nitrate nitrogen, and ammonia nitrogen, and increase the ammonia nitrogen concentration on the basis of step S2 to enable the natural enrichment of anaerobic ammonium oxidation bacteria.

[0012] A further technical solution is that in step S3, the ammonia nitrogen added in the second-stage influent is 3 - 7 mg / L, the nitrate nitrogen is 19 - 27 mg / L, and C / NO3 - is 3 - 6.

[0013] A further technical solution is that it further includes step S4: Conduct the third-stage influent into the two-stage filter system, control the concentrations of influent carbon source, nitrate nitrogen, and ammonia nitrogen, and increase the ammonia nitrogen concentration on the basis of step S3 to strengthen the natural enrichment of anaerobic ammonium oxidation bacteria, and the secondary biological filter realizes the anaerobic ammonium oxidation function.

[0014] A further technical solution is that in step S4, the ammonia nitrogen added in the third-stage influent is 9 - 12 mg / L, the nitrate nitrogen is 19 - 27 mg / L, and C / NO3 - is 3 - 6.

[0015] A further technical solution is that it further includes step S5: Conduct the fourth-stage influent into the two-stage filter system, control the concentrations of influent carbon source, nitrate nitrogen, and ammonia nitrogen, and reduce the ammonia nitrogen concentration on the basis of step S4 to continue the enrichment of anaerobic ammonium oxidation bacteria.

[0016] A further technical solution is that in step S5, the ammonia nitrogen added in the fourth-stage influent is 6 - 8 mg / L, the nitrate nitrogen is 19 - 27 mg / L, and C / NO3 - is 3 - 6.

[0017] A further technical solution is that it further includes step S6: conducting fifth-stage water inlet into the two-stage filter tank system described in S5, controlling the concentrations of influent carbon source, nitrate nitrogen, and ammonia nitrogen, increasing the influent nitrogen concentration on the basis of step S5, and secondarily strengthening the enrichment of anaerobic ammonium oxidation bacteria.

[0018] A further technical solution is that in step S6, the ammonia nitrogen added during the fifth-stage water inlet is 9 - 12 mg / L, the nitrate nitrogen is 19 - 27 mg / L, and C / NO3 - is 3 - 6.

[0019] A further technical solution is that it further includes step S7: separating the secondary biological filter tank as the only filter tank, conducting sixth-stage water inlet into the secondary biological filter tank in which anaerobic ammonium oxidation bacteria have been successfully enriched, and controlling the concentrations of influent carbon source, nitrate nitrogen, and ammonia nitrogen, so as to simultaneously achieve the functions of shortcut denitrification and anaerobic ammonium oxidation in the secondary biological filter tank.

[0020] A further technical solution is that in step S7, the ammonia nitrogen added during the sixth-stage water inlet is 6 - 8 mg / L, the nitrate nitrogen is 10 - 12 mg / L, and C / NO3 - is 3 - 6.

[0021] The present invention provides a device for constructing a shortcut denitrification anaerobic ammonium oxidation filter tank, which includes two biological filter tank reactors, namely a primary biological filter tank and a secondary biological filter tank. Both the primary biological filter tank and the secondary biological filter tank use ceramsite filter media as fillers. The water outlet end of the primary biological filter tank is connected to the water inlet end of the secondary biological filter tank. The primary biological filter tank and the secondary biological filter tank are used for inoculating the activated sludge of a sewage treatment plant and introducing simulated wastewater containing a carbon source, nitrate nitrogen, and ammonia nitrogen. The ceramsite filler is a ceramsite filler with a porosity of 55 - 70%, a particle size range of 3 - 5 mm, a bulk density of 0.75 - 0.85 g / cm 3 and a specific gravity of 1.52 g / cm 3 of the ceramsite filler.

[0022] The working principle of the present invention is: The present invention controls the low C / NO3 of the influent by setting the mode of connecting the secondary biological filter tank in series. --N, the first stage: In the first-stage biological filter, most of the biodegradable organic matter is consumed and short-cut denitrification occurs, producing sufficient nitrite nitrogen to supply the second-stage biological filter. At the same time, it is ensured that there is almost no biodegradable organic matter in the second-stage biological filter for heterotrophic bacteria to utilize. Through the above operations, conditions favorable for the enrichment of anaerobic ammonium oxidation bacteria are created in the second-stage biological filter: 1. There are sufficient substrates, ammonia nitrogen and nitrite nitrogen, required for the growth of anaerobic ammonium oxidation bacteria; 2. The biofilm with the filter as the carrier can ensure the effective retention of anaerobic ammonium oxidation bacteria during the enrichment process; 3. The presence conditions of biodegradable organic matter are restricted in the second-stage biological filter, which can inhibit the growth of heterotrophic bacteria with a faster growth rate, reduce the substrate competition and survival site competition between heterotrophic bacteria and anaerobic ammonium oxidation bacteria, thus creating more favorable growth conditions for anaerobic ammonium oxidation bacteria. The second stage: On the basis of successfully enriching anaerobic ammonium oxidation bacteria in the first stage, the second-stage biological filter is operated independently to enrich short-cut denitrifying bacteria, and finally a short-cut denitrification anaerobic ammonium oxidation filter with anaerobic ammonium oxidation bacteria in the inner layer of the biofilm and short-cut denitrifying bacteria in the outer layer of the biofilm is constructed.

[0023] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0024] (1) The present invention aims at the secondary effluent of a sewage treatment plant containing nitrate and conducts in-depth denitrification treatment on the sewage, overcoming the competition problem between anaerobic ammonium oxidation bacteria and heterotrophic bacteria in an environment rich in organic matter, and providing a new process for in-situ enrichment of anaerobic ammonium oxidation bacteria in a sewage treatment system.

[0025] (2) During the process of enriching anaerobic ammonium oxidation bacteria, the present invention does not artificially add nitrite, reducing the cost consumed by adding chemicals;

[0026] (3) On the premise of not inoculating anaerobic ammonium oxidation bacteria, the present invention can achieve the enrichment of anaerobic ammonium oxidation bacteria from scratch in the subsequent second-stage biological filter;

[0027] (4) The entire enrichment process can ensure that the effluent meets the standards, meaning that the occurrence of the entire enrichment process will not affect the normal operation of the sewage treatment plant in practical applications;

[0028] (5) Anaerobic ammonium oxidation bacteria are successfully enriched in the second-stage biological filter, increasing the proportion of autotrophic total nitrogen removal in the second-stage biological filter, reducing the carbon source consumed for removing unit total nitrogen, saving the artificially added carbon source, and improving the total nitrogen removal efficiency;

[0029] (6) Operating the second-stage biological filter enriched with anaerobic ammonium oxidation bacteria independently can achieve the synchronous removal of ammonia nitrogen and nitrate nitrogen in a single-stage filter, providing a new strategy for promoting the application of short-cut denitrification anaerobic ammonium oxidation technology in a sewage treatment system. Specific embodiments

[0030] The technical solution of the present invention will be described below in conjunction with embodiments. It should be understood that the described embodiments are only a part of the present invention, rather than all embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application should fall within the scope of protection of the present application.

[0031] In an actual sewage treatment plant, the source of the substrate nitrite nitrogen required for enriching anaerobic ammonium oxidation bacteria is that the short-cut denitrification technology can stably provide nitrite nitrogen for anaerobic ammonium oxidation bacteria.

[0032] Based on the above, the present invention proposes a method for inoculating only traditional activated sludge and avoiding in-situ enrichment of anaerobic ammonium oxidation bacteria by connecting two-stage biological filters in series.

[0033] A method for constructing a short-cut denitrification anaerobic ammonium oxidation filter includes the following steps:

[0034] S1: Construct a two-stage filter system, which includes two biological filter reactors. Using ceramsite filter material as the filler, connect two biological filters (primary biological filter and secondary biological filter) in series, and the effluent of the primary biological filter is used as the influent of the secondary biological filter;

[0035] S2: Filler film formation. Inoculate the traditional activated sludge from a sewage treatment plant into the primary biological filter and the secondary biological filter. Conduct the first-stage influent into the two-stage filter system, control the concentrations of influent carbon source, nitrate nitrogen, and ammonia nitrogen, and enable the primary biological filter to achieve the function of short-cut denitrification;

[0036] Further, in the first-stage influent of step S2, the ammonia nitrogen is added at 2-5 mg / L, the nitrate nitrogen is 19-27 mg / L, and C / NO3 - is 3-6.

[0037] S3: Conduct the second-stage influent into the two-stage filter system, control the concentrations of influent carbon source, nitrate nitrogen, and ammonia nitrogen, increase the ammonia nitrogen concentration, and achieve the natural enrichment of anaerobic ammonium oxidation bacteria;

[0038] Further, in the second-stage influent of step S3, the ammonia nitrogen is added at 3-7 mg / L, the nitrate nitrogen is 19-27 mg / L, and C / NO3 - is 3-6.

[0039] S4: Conduct the third-stage influent into the two-stage filter system, control the concentrations of influent carbon source, nitrate nitrogen, and ammonia nitrogen, further increase the ammonia nitrogen concentration, strengthen the natural enrichment of anaerobic ammonium oxidation bacteria, and enable the secondary biological filter to achieve good anaerobic ammonium oxidation function;

[0040] Further, in the third-stage influent of step S4, the ammonia nitrogen is added at 9-12 mg / L, the nitrate nitrogen is 19-27 mg / L, and C / NO3 - is 3-6.

[0041] S5: Conduct the fourth-stage water inlet into the two-stage filter tank system, control the concentrations of influent carbon source, nitrate nitrogen, and ammonia nitrogen, reduce the ammonia nitrogen concentration on the basis of step S4, and continue to enrich anaerobic ammonium oxidation bacteria.

[0042] Further, in the fourth-stage water inlet of step S5, the added ammonia nitrogen is 6 - 8 mg / L, the nitrate nitrogen is 19 - 27 mg / L, and C / NO3 - is 3 - 6.

[0043] S6: Conduct the fifth-stage water inlet into the two-stage filter tank system described in S5, control the concentrations of influent carbon source, nitrate nitrogen, and ammonia nitrogen, further increase the influent nitrogen concentration, and secondarily strengthen the enrichment of anaerobic ammonium oxidation bacteria.

[0044] Further, in the fifth-stage water inlet of step S6, the added ammonia nitrogen is 9 - 12 mg / L, the nitrate nitrogen is 19 - 27 mg / L, and C / NO3 - is 3 - 6.

[0045] S7: Separate the secondary biological filter tank as the only filter tank, conduct the sixth-stage water inlet into the secondary biological filter tank in which anaerobic ammonium oxidation bacteria have been successfully enriched, control the concentrations of influent carbon source, nitrate nitrogen, and ammonia nitrogen, and simultaneously achieve the functions of shortcut denitrification and anaerobic ammonium oxidation in the secondary biological filter tank;

[0046] Further, in the sixth-stage water inlet of step S7, the added ammonia nitrogen is 6 - 8 mg / L, the nitrate nitrogen is 10 - 12 mg / L, and C / NO3 - is 3 - 6.

[0047] Example 1

[0048] Construct a device for a shortcut denitrification anaerobic ammonium oxidation filter tank. There are two biological filter tank reactors, namely a primary biological filter tank and a secondary biological filter tank. The primary biological filter tank and the secondary biological filter tank are in series. The outlet end of the primary biological filter tank is connected to the inlet end of the secondary biological filter tank, that is, the water outlet of the primary biological filter tank serves as the water inlet of the secondary biological filter tank.

[0049] Both the primary biological filter tank and the secondary biological filter tank use ceramsite filler as the filter material, and 700 mL of ceramsite filler is respectively added as the effective working volume; the activated sludge inoculated in the two filter tanks comes from the external return sludge of the Baishamen Sewage Treatment Plant in Haikou, and the MLSS (mixed liquor suspended solids) is 2270 mg / L, and is respectively inoculated into the primary biological filter tank and the secondary biological filter tank so that they are both covered with filter material. The filter material added to the biological filter tank reactor is ceramsite filler, and the porosity of the filler is 55 - 70%; the particle size range is 3 - 5 mm; the bulk density is 0.75 - 0.85 g / cm 3 ; the specific gravity is 1.52 g / cm 3 。

[0050] The first stage: biofilm formation on the packing, and the first-stage biological filter realizes the function of shortcut denitrification. This stage lasts for 25 days.

[0051] The influent water quality is as follows: ammonia nitrogen: 3.1 ± 0.66 mg / L (provided by NH4Cl), nitrate nitrogen: 23.52 ± 2.30 mg / L (provided by NaNO3), COD: 88.74 ± 5.97 mg / L (provided by CH3COONa), C / NO3 - : 3.97 ± 0.43.

[0052] The ammonia nitrogen in the influent of the second-stage biological filter is: 1.19 ± 0.70 mg / L, nitrite nitrogen is: 4.76 ± 1.93 mg / L, nitrate nitrogen is: 2.69 ± 1.24 mg / L, and total nitrogen is: 9.08 ± 3.31 mg / L;

[0053] The ammonia nitrogen in the effluent of the second-stage biological filter is: 1.33 ± 0.57 mg / L, nitrite nitrogen is 3.50 ± 2.50 mg / L, nitrate nitrogen is: 4.58 ± 2.46 mg / L, and total nitrogen is: 7.95 ± 3.30 mg / L.

[0054] Experimental results: Under the condition of controlling C / NO3 - : 3.97 ± 0.43, shortcut denitrification occurred in the first-stage biological filter inoculated with traditional activated sludge, ensuring that there was 4.76 ± 1.93 mg / L of nitrite nitrogen in the influent of the second-stage biological filter, and the biofilm formation was successful.

[0055] The second stage: the enrichment stage of anaerobic ammonium oxidation bacteria. The influent ammonia nitrogen increased, and a weak anaerobic ammonium oxidation reaction occurred in the second-stage biological filter. This stage lasted for 27 days.

[0056] The influent water quality is as follows: ammonia nitrogen: 5.03 ± 1.49 mg / L (provided by NH4Cl), nitrate nitrogen: 24.91 ± 1.71 mg / L (provided by NaNO3), COD: 95.19 ± 8.62 mg / L (provided by CH3COONa), C / NO3-: 3.84 ± 0.57.

[0057] The ammonia nitrogen in the influent of the second-stage biological filter is: 2.35 ± 1.89 mg / L, nitrite nitrogen is: 6.53 ± 3.08 mg / L, nitrate nitrogen is: 6.74 ± 1.60 mg / L, and total nitrogen is: 15.73 ± 4.32 mg / L;

[0058] The ammonia nitrogen in the effluent of the second-stage biological filter is: 1.39 ± 1.37 mg / L, nitrite nitrogen is: 4.23 ± 3.16 mg / L, nitrate nitrogen is: 9.06 ± 2.09 mg / L, and total nitrogen is: 13.03 ± 3.94 mg / L.

[0059] Experimental results: In the secondary biological filter, ammonia nitrogen and nitrite were removed simultaneously, and nitrate nitrogen increased, showing a weak anaerobic ammonium oxidation effect.

[0060] Example 2

[0061] In order to further enrich anaerobic ammonium-oxidizing bacteria, this example further includes, on the basis of the operation in Example 1:

[0062] The third stage: Strengthen the enrichment of anaerobic ammonium-oxidizing bacteria. In this stage, the influent ammonia nitrogen concentration is increased, and this stage lasts for 27 days.

[0063] The influent water quality is as follows: ammonia nitrogen: 10.70 ± 0.41 mg / L (provided by NH4Cl), nitrate nitrogen: 21.27 ± 1.20 mg / L (provided by NaNO3), total nitrogen: 33.31 ± 1.16 mg / L, COD: 109.37 ± 7.20 mg / L (provided by CH3COONa), C / NO3 - : 5.08 ± 0.45.

[0064] The influent ammonia nitrogen in the secondary biological filter is: 4.57 ± 2.16 mg / L, nitrite nitrogen is: 4.69 ± 2.55 mg / L, nitrate nitrogen is: 3.74 ± 1.91 mg / L, and total nitrogen is: 12.72 ± 2.37 mg / L;

[0065] The effluent ammonia nitrogen from the secondary biological filter is: 2.78 ± 1.79 mg / L, nitrite nitrogen is 2.17 ± 1.73 mg / L, nitrate nitrogen is: 6.61 ± 3.61 mg / L, and total nitrogen is: 11.49 ± 2.96 mg / L.

[0066] Experimental results: In the secondary biological filter, ammonia nitrogen and nitrite were still removed simultaneously, and the phenomenon of increased nitrate nitrogen occurred, but the change was not significant, and there was no tendency for the anaerobic ammonium oxidation effect to be enhanced in this stage.

[0067] Example 3

[0068] The fourth stage: Since the strengthening effect in the third stage was not obvious and the effluent total nitrogen was relatively high, the influent ammonia nitrogen concentration was reduced, and the stage of continuing to enrich anaerobic ammonium-oxidizing bacteria lasted for 25 days.

[0069] The influent water quality is as follows: ammonia nitrogen: 7.13 ± 0.84 mg / L (provided by NH4Cl), nitrate nitrogen: 21.79 ± 1.87 mg / L (provided by NaNO3), total nitrogen: 30.55 ± 2.09 mg / L, COD: 92.34 ± 5.01 mg / L (provided by CH3COONa), C / NO3 - : 4.28 ± 0.47.

[0070] The influent ammonia nitrogen of the secondary biological filter is: 4.45 ± 1.03 mg / L, nitrite nitrogen is: 7.29 ± 2.72 mg / L, nitrate nitrogen is: 1.99 ± 0.64 mg / L, and total nitrogen is: 13.54 ± 3.38 mg / L;

[0071] The effluent ammonia nitrogen of the secondary biological filter is: 1.65 ± 1.32 mg / L, nitrite nitrogen is 2.99 ± 2.43 mg / L, nitrate nitrogen is: 2.18 ± 0.77 mg / L, and total nitrogen is: 6.85 ± 2.00 mg / L.

[0072] Experimental results: Although the influent C / NO3 of the secondary biological filter - decreases, the removal amounts of ammonia nitrogen and total nitrogen increase during this stage, indicating that the anaerobic ammonium oxidation effect is obvious.

[0073] Example 4

[0074] The fifth stage: According to the enhanced ammonia nitrogen removal effect and the increase in the total nitrogen removal amount in the fourth stage, further increase the influent ammonia nitrogen concentration to further enrich anaerobic ammonium oxidation bacteria. This stage lasts for 25 days.

[0075] The influent water quality is: ammonia nitrogen: 11.08 ± 0.40 mg / L (provided by NH4Cl), nitrate nitrogen: 22.62 ± 1.03 mg / L (provided by NaNO3), total nitrogen is: 34.88 ± 1.06 mg / L, COD: 91.54 ± 3.89 mg / L (provided by CH3COONa), C / NO3 - : 4.18 ± 0.21.

[0076] The influent ammonia nitrogen of the secondary biological filter is: 8.18 ± 0.87 mg / L, nitrite nitrogen is: 8.64 ± 1.03 mg / L, nitrate nitrogen is: 2.92 ± 1.02 mg / L, and total nitrogen is: 19.77 ± 1.55 mg / L;

[0077] The effluent ammonia nitrogen of the secondary biological filter is: 2.96 ± 0.84 mg / L, nitrite nitrogen is: 0.85 ± 0.20 mg / L, nitrate nitrogen is: 3.40 ± 0.36 mg / L, and total nitrogen is: 7.21 ± 0.79 mg / L.

[0078] Experimental results: The removal amounts of ammonia nitrogen and total nitrogen of the secondary biological filter increase significantly during this stage. The average △COD / △TN of the whole system decreases from 3.41±0.53 in the first stage to 2.29±0.33 in the fifth stage, and the amount of carbon source saved is: 32％ . The total nitrogen removal efficiency increases from 65.1％±13.4％ in the first stage to 79.38％±2.69％ in the fifth stage.

[0079] Method effectiveness verification: Anaerobic ammonium oxidation (anammox) heterotrophic biofilm activity was tested in the laboratory using the filter media from the lower part of the filter tank. 50 mL of filter media from the bottom of the secondary biological filter was added to a 200 mL conical flask, along with 5 mg / L of ammonia nitrogen and nitrite. The mixture was run for 3 hours under the condition of maintaining a dissolved oxygen level of 0 mg / L, and simultaneous removal of ammonia nitrogen and nitrite occurred. The ammonia nitrogen removal rate obtained from the anammox heterotrophic biofilm activity test was compared with that on the 64th day 0.8mgNH4 + -N / L / h , and increased to 3.40mg NH4 + -N / L / h on the 114th day, proving that the biofilm of the filter media in the secondary biological filter has anammox activity. Moreover, with the progress of the enrichment process, the anammox activity increased, indicating the successful enrichment of anammox bacteria.

[0080] Phase 6: The secondary biological filter enriched with anammox bacteria was operated independently to investigate whether it could independently complete the functions of shortcut denitrification and anammox. The influent contained ammonia nitrogen, nitrate nitrogen, and sodium acetate, and this phase lasted for 12 days.

[0081] The influent water quality was as follows: ammonia nitrogen: 7.18 ± 0.54 mg / L (provided by NH4Cl), nitrate nitrogen: 11.94 ± 1.07 mg / L (provided by NaNO3), COD: 50.57 ± 3.88 mg / L (provided by CH3COONa), C / NO3 - : 4.54 ± 0.72, and total nitrogen was: 19.15 ± 1.13 mg / L;

[0082] The effluent water quality was as follows: ammonia nitrogen: 3.59 ± 0.77 mg / L, nitrite nitrogen: 2.31 ± 0.92 mg / L, nitrate nitrogen: 0.94 ± 0.49 mg / L, COD: 25.57 ± 4.91 mg / L, and total nitrogen was: 6.72 ± 1.23 mg / L.

[0083] Experimental results: The secondary biological filter was successfully enriched with shortcut denitrifying bacteria when operated independently, achieving simultaneous removal of ammonia nitrogen and nitrate nitrogen. The total nitrogen in the effluent reached the first-class A standard. The amount of ammonia nitrogen removed was 3.39 ± 0.48 mg / L. When the influent NLR was 0.55 ± 0.04 kg N / m 3 / d, an NRR of 0.36 ± 0.05 kg N / m 3 / d was achieved, and △COD / △TN was: 2.33 ± 0.38.

[0084] The above content is a further detailed description of the present invention in combination with specific preferred embodiments. It cannot be determined that the specific implementation of the present invention is only limited to these descriptions. For those of ordinary skill in the technical field to which the present invention belongs, without departing from the concept of the present invention, several simple deductions and substitutions can still be made, and all should be regarded as belonging to the protection scope of the present invention.

Claims

1. A method for constructing a short-cut denitrification and anammox filter, characterized in that, It includes the following steps: S1: Set up two biological filter reactors, namely a primary biological filter and a secondary biological filter. Both the primary biological filter and the secondary biological filter use ceramsite filter media as fillers. The effluent of the primary biological filter serves as the influent of the secondary biological filter to construct a two-stage filter system; S2: Film formation on the filler. Inoculate the traditional activated sludge from a sewage treatment plant into the primary biological filter and the secondary biological filter. Conduct the first-stage influent into the two-stage filter system, and control the concentrations of influent carbon source, nitrate nitrogen, and ammonia nitrogen so that the primary biological filter realizes the function of shortcut denitrification; S3: Conduct the second-stage influent into the two-stage filter system, and control the concentrations of influent carbon source, nitrate nitrogen, and ammonia nitrogen. Increase the ammonia nitrogen concentration based on step S2 to enable the natural enrichment of anaerobic ammonia-oxidizing bacteria; S4: Conduct the third-stage influent into the two-stage filter system, and control the concentrations of influent carbon source, nitrate nitrogen, and ammonia nitrogen. Increase the ammonia nitrogen concentration based on step S3 to strengthen the natural enrichment of anaerobic ammonia-oxidizing bacteria, and the secondary biological filter realizes the function of anaerobic ammonia oxidation; S5: Conduct the fourth-stage influent into the two-stage filter system, and control the concentrations of influent carbon source, nitrate nitrogen, and ammonia nitrogen. Decrease the ammonia nitrogen concentration based on step S4 and continue the enrichment of anaerobic ammonia-oxidizing bacteria; S6: Conduct the fifth-stage influent into the two-stage filter system described in S5, and control the concentrations of influent carbon source, nitrate nitrogen, and ammonia nitrogen. Increase the influent nitrogen concentration based on step S5 to secondarily strengthen the enrichment of anaerobic ammonia-oxidizing bacteria; S7: Separate the secondary biological filter as the only filter, and conduct the sixth-stage influent into the secondary biological filter in which anaerobic ammonia-oxidizing bacteria have been successfully enriched. Control the concentrations of influent carbon source, nitrate nitrogen, and ammonia nitrogen so that both shortcut denitrification and anaerobic ammonia oxidation functions are realized in the secondary biological filter; Step S2, in the first-stage water inlet, the ammonia nitrogen is added at 2-5 mg / L, the nitrate nitrogen is 19-27 mg / L, and C / NO3 - is 3-6; Step S3, in the second-stage water inlet, the ammonia nitrogen is added at 3 - 7 mg / L, the nitrate nitrogen is 19 - 27 mg / L, and C / NO3 - is 3 - 6; Step S4, in the third-stage water inlet, the ammonia nitrogen is added at 9-12 mg / L, the nitrate nitrogen is 19-27 mg / L, and C / NO3 - is 3-6; Step S5, in the fourth stage, ammonia nitrogen is added at 6 - 8 mg / L, nitrate nitrogen is added at 19 - 27 mg / L, and C / NO3 - is 3 - 6; Step S6, in the fifth stage, ammonia nitrogen is added during water inlet at 9 - 12 mg / L, nitrate nitrogen is 19 - 27 mg / L, and C / NO3 - is 3 - 6; Step S7, in the sixth stage, ammonia nitrogen is added during water inlet at 6 - 8 mg / L, nitrate nitrogen at 10 - 12 mg / L, and C / NO3 - is 3 - 6.