A method for simultaneously improving the denitrification efficiency of sewage and degrading new pollutants

Abstract

The present application belongs to the technical field of sewage treatment, and particularly relates to a method for simultaneously improving the denitrification efficiency of sewage and degrading new pollutants. Alcaligenes The present application adopts a new strain of Alcaligenes sp. FDN-09 which is resistant to perfluorinated compounds to carry out large-scale culture, and prepares a high-efficiency functional bacterial agent; under the condition that ammonia nitrogen and new pollutants coexist in sewage, the high-efficiency functional bacterial agent is added in a biological reactor, and the reactor is operated under anoxic and low-oxygen conditions, thereby simultaneously strengthening the removal of ammonia nitrogen and new pollutants in the sewage, and achieving the effect of improving the denitrification of the sewage treatment system while degrading new pollutants. The method of the present application has no secondary pollution to the environment, has high simultaneous degradation rates of total nitrogen and new pollutants, low treatment cost, and low carbon emission. Under the condition that ammonia nitrogen and new pollutants coexist in the sewage, the water quality of the effluent is far lower than the first-level A effluent standard in the modification single of the Discharge Standard of Pollutants for Municipal Wastewater Treatment Plant (GB 18918-2002).

Description

Technical Field

[0001] This invention belongs to the field of wastewater treatment technology, specifically, it relates to a method for simultaneously improving wastewater denitrification efficiency and degrading new pollutants. Background Technology

[0002] With rapid economic and social development, the production and use of chemicals continue to expand, leading to the emergence of new pollutants such as antibiotics and endocrine disruptors. These new pollutants pose a significant challenge to conventional biological treatment technologies in wastewater treatment plants.

[0003] In recent years, the cultivation of highly efficient bacterial strains to improve wastewater denitrification has attracted considerable attention. Chinese invention patent application CN117070415A screened a highly efficient denitrifying bacterial strain with dissimilatory reduction to ammonium function: *Aeromonas media L20*, an aerobic denitrifying bacterium with high nitrate and nitrite enzyme activity. This strain, possessing dissimilatory reduction to ammonium function, can rapidly remove nitrate nitrogen from water while effectively reducing nitrogen oxide emissions. Another Chinese invention patent application CN120624253A uses weak ultrasonic treatment to treat the denitrifying bacterial strain *Paracoccus denitrificans* to mitigate the inhibitory effect of perfluorinated compounds (PFCs) on the strain and improve its resistance. While these strains achieved good denitrification results, they lacked the ability to simultaneously degrade new pollutants in wastewater. Therefore, there is an urgent need to develop new methods to improve wastewater denitrification efficiency and simultaneously degrade new pollutants, enabling the simultaneous removal of ammonia nitrogen and new pollutants from actual wastewater. Without altering existing wastewater treatment facilities, in-situ upgrades and renovations can be carried out to reduce the stress of new pollutants on the biological denitrification system, ensuring that the effluent quality consistently meets the revised "Discharge Standard of Pollutants for Municipal Wastewater Treatment Plants" (GB18918-2002) (effective March 1, 2026). This will not only satisfy the average value of the "basic control item discharge limits" but also meet the "instantaneous value requirements for major water pollutants". Summary of the Invention

[0004] To address the issues of low efficiency in both nitrogen removal and degradation of new pollutants in existing biological treatment technologies, this invention aims to provide a method that simultaneously improves nitrogen removal efficiency and degrades new pollutants in wastewater. This method is safe, convenient, highly efficient in degrading ammonia nitrogen and new pollutants, has low energy consumption, low carbon emissions, and causes no secondary pollution to the environment. This invention involves adding highly efficient functional bacteria to a bioreactor. The dosage of the highly efficient functional bacteria and the operating procedures of the bioreactor can be automatically controlled based on the original wastewater quality and operating parameters. Under conditions where ammonia nitrogen and new pollutants coexist in the wastewater, this method can produce effluent quality far below the Class A effluent standards (ammonia nitrogen ≤ 5 mg / L; total nitrogen ≤ 15 mg / L) in the revised "Discharge Standard of Pollutants for Municipal Wastewater Treatment Plants" (GB18918-2002).

[0005] The technical solution of the present invention is described in detail below.

[0006] This invention provides a method for simultaneously improving wastewater denitrification efficiency and degrading new pollutants, which employs a novel strain of alkali-producing bacteria resistant to perfluorinated compounds (Alcaligenes spp.). Alcaligenes A highly efficient functional bacterial agent obtained by expanding the culture of FDN-09 (gene sequence number Genbank PV230506) was added to a bioreactor to treat wastewater under anoxic and hypoxic conditions (DO 0.2–1.0 mg / L), while simultaneously enhancing the removal of ammonia nitrogen and new pollutants from the wastewater; wherein: the alkali-producing strain ( Alcaligenes The accession number for sp.) FDN-09 is CGMCC No.37405.

[0007] In this invention, the new pollutants in the wastewater are selected from one or more of diclofenac, perfluorooctanoic acid, or tetrabromobisphenol A; the initial concentration of ammonia nitrogen in the wastewater is between 20 and 50 mg / L, and the concentration of a single new pollutant is between 10 ng / L and 500 μg / L.

[0008] In this invention, activated sludge acclimated with perfluorinated compounds is added to the bioreactor as inoculum sludge, and the C / N ratio is controlled between 2.0 and 6.0; the wastewater is treated with anoxic, hypoxic, and then anoxic processes.

[0009] In this invention, during wastewater treatment, the wastewater is first subjected to anoxic treatment for 2 to 4 hours, followed by low-oxygen treatment for 2 to 4 hours, and then anoxic treatment for 0.5 to 1.5 hours.

[0010] In this invention, during the low-oxygen treatment, the dissolved oxygen (DO) concentration is 0.2–1.0 mg / L.

[0011] In this invention, the inoculum quantity of the highly efficient functional bacterial agent is 1-5 vol.

[0012] The preparation method of the highly efficient functional bacterial agent in this invention is as follows: (1) Activated sludge was added to the sequencing batch biofilm reactor (SBBR) and subjected to anoxic stirring and low-oxygen aeration. Nutrient solution was provided to the microorganisms in the SBBR, with sodium succinate as the carbon source and ammonium chloride as the nitrogen source. The microorganisms were acclimated with a new pollutant, perfluorinated compound, at a temperature of 20–22°C for 80–90 days, and a biofilm was formed on the packing material. Then, the highly efficient functional bacteria enriched on the biofilm were isolated and screened to obtain alkali-producing strains ( Alcaligenes sp.)FDN-09; (2) A new strain of alkali-producing bacteria resistant to perfluorinated compounds ( Alcaligenes FDN-09 (sp.) was added to LB liquid medium and cultured in a shaker for 45–55 h to obtain a highly efficient functional bacterial agent.

[0013] In this invention, the bioreactor is a sequencing batch reactor (SBR), a sequencing batch bioreactor (SBR), or a continuous flow bioreactor. A submersible mixer and a tubular aerator are installed in the SBR; a submersible mixer, braided packing material, and a tubular aerator are installed in the SBR; and a submersible mixer is installed in the anoxic zone and a tubular aerator is installed in the hypoxic zone of the continuous flow bioreactor.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) The method in this invention can achieve the effect of denitrification of wastewater and degradation of new pollutants (dehalogenation to reduce the toxicity of new pollutants) under the condition that ammonia nitrogen and new pollutants coexist in wastewater.

[0015] (2) Alkali-producing strains ( Alcaligenes FDN-09 (sp.) is a strain cultured and screened in the laboratory. It has the characteristics of simultaneously and efficiently degrading ammonia nitrogen and new pollutants. It can remove ammonia nitrogen and new pollutants from wastewater at the same time and significantly reduce costs.

[0016] (3) New strains of Alcaligenes ( Alcaligenes FDN-09 (sp.) has the ability to directly convert ammonia nitrogen into nitrogen gas without producing the greenhouse gas nitrous oxide, thus reducing carbon emissions.

[0017] (4) The operation program of the bioreactor can be intelligently controlled, and the dosage of high-efficiency functional bacteria can be automatically controlled according to the original sewage quality and operating parameters, making it convenient and safe to operate.

[0018] (5) The addition of highly efficient functional bacterial agents greatly improves the degradation rate of ammonia nitrogen and new pollutants in wastewater. Using the method of this invention, under the condition that ammonia nitrogen and new pollutants coexist in wastewater, the effluent quality is far lower than the Class A effluent standard (ammonia nitrogen ≤ 5 mg / L; total nitrogen ≤ 15 mg / L) in the revised "Discharge Standard of Pollutants for Municipal Wastewater Treatment Plants" (GB18918-2002), and stably reaches the instantaneous Class A effluent standard (ammonia nitrogen ≤ 10 mg / L; total nitrogen ≤ 20 mg / L) in the revised standard. Attached Figure Description

[0019] Figure 1 This is a microscopic image of the individual morphological characteristics of the FDN-09 strain of the present invention. Detailed Implementation

[0020] The technical solution of the present invention will be described in detail below with reference to the accompanying drawings and embodiments.

[0021] In the examples, alkali-producing strains ( Alcaligenes The method for obtaining FDN-09 (sp.) is as follows: Returned activated sludge from the secondary sedimentation tank of a wastewater treatment plant was added to the SBBR, followed by anoxic stirring and low-oxygen (DO 0.2–1.0 mg / L) aeration. Nutrient solution was provided to the microorganisms in the SBBR, with sodium succinate as the carbon source and ammonium chloride as the nitrogen source. The microorganisms were acclimated to new pollutants (perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS)) at 20–22°C for 80–90 days, resulting in the formation of a biofilm on the packing material. The highly efficient functional bacteria enriched on the biofilm were then isolated and screened to obtain the alkali-producing strain (…). Alcaligenes sp.)FDN-09.

[0022] The highly efficient functional bacterial agent of this invention is composed of alkali-producing bacterial strains ( Alcaligenes FDN-09 (sp.) is a newly discovered strain. It was deposited on January 15, 2026, at the China General Microbiological Culture Collection Center (CGMCC), located at the Institute of Microbiology, Chinese Academy of Sciences, Datun Road, Chaoyang District, Beijing, with accession number CGMCC No. 37405.

[0023] Figure 1 (a) and Figure 1Image (b) shows the morphological characteristics of the FDN-09 strain of this invention. Its colonies are round, milky white, and opaque. The bacteria are rod-shaped, with a single cell length of approximately 1.8 μm, a relatively short width, and uniform morphology. FDN-09 is a newly discovered strain capable of simultaneously removing ammonia nitrogen and new contaminants; it is *Alcaligenes faecalis*, Genbank Sequence_ID PV230506.

[0024] This invention utilizes a self-designed bioreactor for experiments on removing ammonia nitrogen and new pollutants. The specific device structure is described below: the casing is a cuboid or cylinder, made of quartz glass. A submersible mixer and tubular aerator are installed in the sequencing batch reactor (SBR); a submersible mixer, braided packing, and tubular aerator are installed in the sequencing batch biofilm reactor (SBR); and a submersible mixer is installed in the anoxic zone and a tubular aerator in the hypoxic zone of the continuous flow bioreactor. The bioreactor is equipped with an inlet, outlet, and sludge discharge port. The device is fully automated, making operation convenient and safe.

[0025] Example 1

[0026] In this embodiment, an alkali-producing strain resistant to perfluorinated compounds (20 μg / L) was used. Alcaligenes FDN-09 (sp.) was inoculated into LB liquid medium and cultured in a shaker for 45–55 h to obtain a highly efficient functional bacterial agent. Simulated wastewater containing ammonia nitrogen and a new pollutant (initial concentration of ammonia nitrogen: 40 mg / L; initial concentration of diclofenac: 200 μg / L) was added. 500 mL of activated sludge acclimated with perfluorinated compounds and 500 mL of simulated wastewater (C / N ratio: 5.0) were added to a sequencing batch reactor (SBR). 20 mL (2 vol% inoculation rate) of the highly efficient functional bacterial agent was added to the SBR. The treatment was followed by anoxic treatment for 3 h, then hypoxic treatment (DO: 0.2–1.0 mg / L) for 3 h, then anoxic treatment for 1 h, followed by sedimentation for 1 h. The wastewater treatment time was 8 h. Small-scale test results showed that the degradation rate of ammonia nitrogen and the new pollutant in the simulated wastewater was 100%, and the total nitrogen removal rate reached over 85%. Under conditions where ammonia nitrogen and new pollutants coexist in the wastewater, the effluent quality is far below the Class A effluent standard (ammonia nitrogen ≤ 5 mg / L; total nitrogen ≤ 15 mg / L) in the revised "Discharge Standard of Pollutants for Municipal Wastewater Treatment Plants" (GB18918-2002).

[0027] Example 2

[0028] In this embodiment, an alkali-producing strain resistant to perfluorinated compounds (20 μg / L) was used. AlcaligenesFDN-09 (sp.) was inoculated into LB liquid medium and cultured in a shaker for 45–55 h to obtain a highly efficient functional bacterial agent. Simulated wastewater containing ammonia nitrogen and new pollutants was used, with initial concentrations of ammonia nitrogen (40 mg / L), diclofenac (200 μg / L), and perfluorooctanoic acid (PFOA) (200 ng / L). 500 mL of activated sludge acclimated with perfluorinated compounds and 500 mL of simulated wastewater (C / N ratio 5.0) were added to a sequencing batch reactor (SBR). 20 mL (2 vol% inoculation) of the highly efficient functional bacterial agent was added to the SBR. The treatment was followed by anoxic treatment for 3 h, hypoxic treatment (DO 0.2–1.0 mg / L) for 3 h, then anoxic treatment for 1 h, followed by sedimentation for 1 h, for a total wastewater treatment time of 8 h. Small-scale test results showed that the degradation rate of ammonia nitrogen and new pollutants in the simulated wastewater was 100%, and the total nitrogen removal rate reached over 85%. Under conditions where ammonia nitrogen and new pollutants coexist in the wastewater, the effluent quality is far below the Class A effluent standard (ammonia nitrogen ≤ 5 mg / L; total nitrogen ≤ 15 mg / L) in the revised "Discharge Standard of Pollutants for Municipal Wastewater Treatment Plants" (GB18918-2002).

[0029] Example 3

[0030] In this embodiment, an alkali-producing strain resistant to perfluorinated compounds (20 μg / L) was used. Alcaligenes FDN-09 (sp.) was inoculated into LB liquid medium and cultured in a shaker for 45–55 h to obtain a highly efficient functional bacterial agent. Simulated wastewater containing ammonia nitrogen and new pollutants was used, with initial concentrations of ammonia nitrogen (40 mg / L), diclofenac (200 μg / L), perfluorooctanoic acid (200 ng / L), and tetrabromobisphenol A (20 μg / L). 500 mL of activated sludge acclimated with perfluorinated compounds and 500 mL of simulated wastewater (C / N ratio 5.0) were added to a sequencing batch reactor (SBR). 20 mL (2 vol% inoculum) of the highly efficient functional bacterial agent was added to the SBR. The treatment was followed by anoxic treatment for 3 h, hypoxic treatment (DO 0.2–1.0 mg / L) for 3 h, then anoxic treatment for 1 h, followed by sedimentation for 1 h, for a total wastewater treatment time of 8 h. Small-scale test results showed that the degradation rate of ammonia nitrogen and new pollutants in the simulated wastewater was 100%, and the total nitrogen removal rate reached over 85%. Under conditions where ammonia nitrogen and new pollutants coexist in the wastewater, the effluent quality is far below the Class A effluent standard (ammonia nitrogen ≤ 5 mg / L; total nitrogen ≤ 15 mg / L) in the revised "Discharge Standard of Pollutants for Municipal Wastewater Treatment Plants" (GB18918-2002).

[0031] Example 4

[0032] In this embodiment, an alkali-producing strain resistant to perfluorinated compounds (20 μg / L) was used. Alcaligenes FDN-09 (sp.) was inoculated into LB liquid medium and cultured in a shaker for 45–55 h to obtain a highly efficient functional bacterial agent. Simulated wastewater containing ammonia nitrogen and a new pollutant (initial concentration of ammonia nitrogen 50 mg / L and diclofenac 10 μg / L) was added to a sequencing batch reactor (SBR). 500 mL of activated sludge acclimated with perfluorinated compounds and 500 mL of simulated wastewater (C / N ratio 4.0) were added to the SBR. 50 mL (5 vol% inoculum) of the highly efficient functional bacterial agent was added to the SBR. The treatment process included anoxic treatment for 3 h, followed by hypoxic treatment (DO 0.2–1.0 mg / L) for 2 h, then anoxic treatment for 1 h, sedimentation for 1 h, and resting for 1 h, for a total wastewater treatment time of 8 h. Small-scale test results showed that the degradation rate of ammonia nitrogen and the new pollutant in the simulated wastewater was 100%, and the total nitrogen removal rate reached over 90%. Under conditions where ammonia nitrogen and new pollutants coexist in the wastewater, the effluent quality is far below the Class A effluent standard (ammonia nitrogen ≤ 5 mg / L; total nitrogen ≤ 15 mg / L) in the revised "Discharge Standard of Pollutants for Municipal Wastewater Treatment Plants" (GB18918-2002).

[0033] Example 5

[0034] In this embodiment, an alkali-producing strain resistant to perfluorinated compounds (20 μg / L) was used. Alcaligenes FDN-09 (sp.) was inoculated into LB liquid medium and cultured in a shaker for 45–55 h to obtain a highly efficient functional bacterial agent. Simulated wastewater containing ammonia nitrogen and new pollutants was used, with initial concentrations of ammonia nitrogen (50 mg / L), diclofenac (10 μg / L), and perfluorooctanoic acid (PFOA) (100 ng / L). 500 mL of activated sludge acclimated with perfluorinated compounds and 500 mL of simulated wastewater (C / N ratio 4.0) were added to a sequencing batch reactor (SBR). 50 mL (5 vol% inoculum) of the highly efficient functional bacterial agent was added to the SBR. The treatment process included anoxic treatment for 3 h, followed by hypoxic treatment (DO 0.2–1.0 mg / L) for 2 h, then anoxic treatment for 1 h, sedimentation for 1 h, and resting for 1 h, for a total wastewater treatment time of 8 h. Small-scale test results showed that the degradation rate of ammonia nitrogen and new pollutants in the simulated wastewater was 100%, and the total nitrogen removal rate reached over 90%. Under conditions where ammonia nitrogen and new pollutants coexist in the wastewater, the effluent quality is far below the Class A effluent standard (ammonia nitrogen ≤ 5 mg / L; total nitrogen ≤ 15 mg / L) in the revised "Discharge Standard of Pollutants for Municipal Wastewater Treatment Plants" (GB18918-2002).

[0035] Example 6

[0036] In this embodiment, an alkali-producing strain resistant to perfluorinated compounds (20 μg / L) was used. Alcaligenes FDN-09 (sp.) was inoculated into LB liquid medium and cultured in a shaker for 45–55 h to obtain a highly efficient functional bacterial agent. Simulated wastewater containing ammonia nitrogen and new pollutants was used, with initial concentrations of ammonia nitrogen (50 mg / L), diclofenac (10 μg / L), perfluorooctanoic acid (100 ng / L), and tetrabromobisphenol A (10 μg / L). 500 mL of activated sludge acclimated with perfluorinated compounds and 500 mL of simulated wastewater (C / N ratio 4.0) were added to an SBBR (Sequencing Batch Biofilm Reactor). 50 mL (5 vol% inoculum) of the highly efficient functional bacterial agent was added to the reactor. The treatment process included anoxic treatment for 3 h, followed by hypoxic treatment (DO 0.2–1.0 mg / L) for 2 h, then anoxic treatment for 1 h, sedimentation for 1 h, and resting for 1 h, for a total wastewater treatment time of 8 h. The results of the small-scale test showed that the degradation rate of ammonia nitrogen and new pollutants in the simulated wastewater was 100%, and the total nitrogen removal rate reached over 90%. Under the condition of coexistence of ammonia nitrogen and new pollutants in the wastewater, the effluent quality was far lower than the Class A effluent standard (ammonia nitrogen ≤ 5 mg / L; total nitrogen ≤ 15 mg / L) in the revised "Discharge Standard of Pollutants for Municipal Wastewater Treatment Plants" (GB18918-2002).

[0037] Example 7

[0038] In this embodiment, an alkali-producing strain resistant to perfluorinated compounds (20 μg / L) was used. Alcaligenes FDN-09 (sp.) was inoculated into LB liquid medium and cultured in a shaker for 45–55 h to obtain a highly efficient functional bacterial agent. Simulated wastewater containing ammonia nitrogen and new pollutants, with an initial ammonia nitrogen concentration of 35 mg / L and an initial concentration of diclofenac at 10 μg / L, was used. 500 mL of activated sludge acclimated with perfluorinated compounds was added to the anoxic zone before the continuous flow bioreactor. The simulated wastewater influent flow rate was 125 mL / h, the C / N ratio was 6.0, and 30 mL (3 vol% inoculum) of the highly efficient functional bacterial agent was added to the anoxic zone before the continuous flow bioreactor. The treatment was followed by anoxic treatment for 4 h, then hypoxia (DO 0.2–1.0 mg / L) for 3 h, and then anoxic treatment for 1 h. The wastewater retention time was 8 h. The sludge was returned to the anoxic zone at a sludge return ratio of 50–100%. Small-scale test results showed that the degradation rate of ammonia nitrogen and new pollutants in the simulated wastewater was 100%, and the total nitrogen removal rate reached over 90%. Under conditions where ammonia nitrogen and new pollutants coexist in the wastewater, the effluent quality is far below the Class A effluent standard (ammonia nitrogen ≤ 5 mg / L; total nitrogen ≤ 15 mg / L) in the revised "Discharge Standard of Pollutants for Municipal Wastewater Treatment Plants" (GB18918-2002).

[0039] Example 8

[0040] In this embodiment, an alkali-producing strain resistant to perfluorinated compounds (20 μg / L) was used. Alcaligenes FDN-09 (sp.) was inoculated into LB liquid medium and cultured in a shaker for 45–55 h to obtain a highly efficient functional bacterial agent. Simulated wastewater containing ammonia nitrogen and new pollutants was used, with initial concentrations of ammonia nitrogen (35 mg / L), diclofenac (10 μg / L), and perfluorooctanoic acid (PFOA) (100 ng / L). 500 mL of activated sludge acclimated with perfluorinated compounds was added to the anoxic zone before the continuous flow bioreactor. The simulated wastewater influent flow rate was 125 mL / h, with a C / N ratio of 6.0. 30 mL (3 vol% inoculum) of the highly efficient functional bacterial agent was added to the anoxic zone before the continuous flow bioreactor. The treatment consisted of anoxic treatment for 4 h, followed by hypoxia (DO 0.2–1.0 mg / L) for 3 h, and then another anoxic treatment for 1 h. The wastewater retention time was 8 h. The sludge was returned to the anoxic zone at a sludge return ratio of 50–100%. The results of the small-scale test showed that the degradation rate of ammonia nitrogen and new pollutants in the simulated wastewater was 100%, and the total nitrogen removal rate reached over 90%. Under the condition of coexistence of ammonia nitrogen and new pollutants in the wastewater, the effluent quality was far lower than the Class A effluent standard (ammonia nitrogen ≤ 5 mg / L; total nitrogen ≤ 15 mg / L) in the revised "Discharge Standard of Pollutants for Municipal Wastewater Treatment Plants" (GB18918-2002).

[0041] Example 9

[0042] In this embodiment, an alkali-producing strain resistant to perfluorinated compounds (20 μg / L) was used. AlcaligenesFDN-09 (sp.) was inoculated into LB liquid medium and cultured in a shaker for 45–55 h to obtain a highly efficient functional bacterial agent. Simulated wastewater containing ammonia nitrogen and new pollutants was used, with initial concentrations of ammonia nitrogen (35 mg / L), diclofenac (10 μg / L), perfluorooctanoic acid (100 ng / L), and tetrabromobisphenol A (10 μg / L). 500 mL of activated sludge acclimated with perfluorinated compounds was added to the anoxic zone before the continuous flow bioreactor. The simulated wastewater influent flow rate was 125 mL / h, the C / N ratio was 6.0, and 30 mL (3 vol% inoculum) of the highly efficient functional bacterial agent was added to the anoxic zone before the continuous flow bioreactor. The treatment consisted of anoxic treatment for 4 h, followed by hypoxia (DO 0.2–1.0 mg / L) for 3 h, and then another anoxic treatment for 1 h, with a wastewater retention time of 8 h. The sludge was then returned to the anoxic zone at a sludge return ratio of 50–100%. The results of the small-scale test showed that the degradation rate of ammonia nitrogen and new pollutants in the simulated wastewater was 100%, and the total nitrogen removal rate reached over 90%. Under the condition of coexistence of ammonia nitrogen and new pollutants in the wastewater, the effluent quality was far lower than the Class A effluent standard (ammonia nitrogen ≤ 5 mg / L; total nitrogen ≤ 15 mg / L) in the revised "Discharge Standard of Pollutants for Municipal Wastewater Treatment Plants" (GB18918-2002).

Claims

1. A method for simultaneously improving wastewater denitrification efficiency and degrading new pollutants, characterized in that, Alcaligenes strains resistant to perfluorinated compounds were used. Alcaligenes The highly efficient functional bacterial agent obtained by expanding the culture of FDN-09 (sp.) was added to a bioreactor to treat wastewater under anoxic and hypoxic conditions, while simultaneously enhancing the removal of ammonia nitrogen and new pollutants from the wastewater; wherein: the alkali-producing strain ( Alcaligenes The accession number for sp.) FDN-09 is CGMCC No.37405.

2. The method according to claim 1, characterized in that, The new pollutants in the wastewater are selected from one or more of diclofenac, perfluorooctanoic acid, or tetrabromobisphenol A. Dehalogenation reduces the toxicity of the new pollutants. The initial concentration of ammonia nitrogen in the wastewater is between 20 and 50 mg / L, and the concentration of a single new pollutant is between 10 ng / L and 500 μg / L.

3. The method according to claim 1, characterized in that, In the bioreactor, activated sludge acclimated with perfluorinated compounds was added as inoculum sludge; the C / N mass ratio was controlled between 2.0 and 6.0; the wastewater was treated with anoxic, hypoxic, and then anoxic processes.

4. The method according to claim 3, characterized in that, During wastewater treatment, the wastewater is first treated with anoxic conditions for 2–4 hours, followed by low-oxygen conditions for 2–4 hours, and then with anoxic conditions for 0.5–1.5 hours.

5. The method according to claim 3, characterized in that, During low-oxygen treatment, the dissolved oxygen (DO) concentration is 0.2–1.0 mg / L.

6. The method according to claim 1, characterized in that, The inoculation rate of highly effective functional bacterial agents is 1-5 vol.

7. The method according to claim 1, characterized in that, The preparation method of highly effective functional bacterial agents is as follows: (1) Activated sludge was added to the sequencing batch biofilm reactor (SBBR) and subjected to anoxic stirring and low-oxygen aeration. Nutrient solution was provided to the microorganisms in the SBBR, with sodium succinate as the carbon source and ammonium chloride as the nitrogen source. The microorganisms were acclimated with a new pollutant, perfluorinated compound, at a temperature of 20–22°C for 80–90 days, and a biofilm was formed on the packing material. Then, the highly efficient functional bacteria enriched on the biofilm were isolated and screened to obtain alkali-producing strains ( Alcaligenes sp.)FDN-09; (2) A new strain of alkali-producing bacteria resistant to perfluorinated compounds ( Alcaligenes FDN-09 (sp.) was added to LB liquid medium and cultured in a shaker for 45–55 h to obtain a highly efficient functional bacterial agent.

8. The method according to claim 1, characterized in that, The bioreactor can be a sequencing batch reactor (SBR), a sequencing batch bioreactor (SBR), or a continuous flow bioreactor. A SBR is equipped with a submersible mixer and a tubular aerator. A SBR is equipped with a submersible mixer, a braided packing material, and a tubular aerator. In a continuous flow bioreactor, a submersible mixer is installed in the anoxic zone and a tubular aerator is installed in the hypoxic zone.

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