Method for improving total nitrogen removal rate of effluent of ozone advanced oxidation wastewater treatment process by coupling autotrophic denitrification microbial reactor

Abstract

The invention relates to a method for improving the total nitrogen removal rate of effluent of an ozone advanced oxidation wastewater treatment process by coupling an autotrophic denitrification microbial reactor. The method specifically comprises the following steps: adjusting the pH value of the wastewater containing the aromatic organic pollutants to 6.0-7.0, and continuously introducing ozone; adding a hydrogen peroxide solution, controlling the reaction temperature, detecting the concentration of the aromatic organic pollutants in the wastewater, detecting the turbidity value of effluent after the total concentration of the aromatic organic pollutants in the wastewater is reduced to 6mg / L, and adding a flocculating agent; and introducing the effluent into an EGSB anaerobic bioreactor, introducing wastewater containing ammonia nitrogen, treating the wastewater by the EGSB anaerobic bioreactor, and discharging after the wastewater reaches the standard. According to the method disclosed by the invention, by optimizing treatment parameters of an ozone advanced oxidation technology, effluent containing a large amount of nitrogen and a small amount of organic matters and other external wastewater containing a large amount of ammonia nitrogen are jointly introduced into the autotrophic denitrification microbial reactor, so that the effect of economically and efficiently treating the chemical wastewater in a standard reaching manner is realized.

Description

Technical Field

[0001] The present invention relates to the technical field of sewage and wastewater purification treatment, and in particular to a method for coupling autotrophic denitrifying microorganisms in a reactor to improve the total nitrogen removal rate of the effluent of an ozonation advanced oxidation wastewater treatment process. Background Art

[0002] With the rapid development of the economic society, the wastewater discharge of the chemical industry continues to increase. The organic pollutants in chemical wastewater will cause great harm to the water ecological environment. Chemical wastewater usually has the following characteristics: large output, complex composition, high salinity, strong toxicity, poor biodegradability, etc.

[0003] The most common volatile and slightly water-soluble organic pollutants in chemical wastewater, such as benzene, toluene, aniline, etc., are likely to enter natural water bodies in different forms, and these organic pollutants are difficult to be degraded by the self-purification of the environment itself. Eventually, they will accumulate in the environment, continuously causing harm to the ecosystem, and even causing teratogenic and carcinogenic injuries to animals, plants and humans.

[0004] Currently widely used wastewater treatment technologies, such as the activated sludge method, the biofilm method, etc., are difficult to treat substances containing benzene rings in chemical wastewater. The advanced oxidation method has been proven to be able to effectively remove refractory organic matter in wastewater. The ozonation advanced oxidation technology is one of the greenest and most efficient technologies for degrading organic pollutants in the current water treatment research field. Through the hydroxyl radicals generated by ozone and hydrogen peroxide, it can non-selectively oxidize and degrade the organic pollutants in the wastewater, and has good application prospects.

[0005] However, if the ozonation advanced oxidation technology is used to completely degrade benzene, toluene, aniline and other pollutants in chemical wastewater, it is necessary to continuously introduce ozone and add an excessive amount of hydrogen peroxide to generate hydroxyl radicals, resulting in high operating costs, and the inorganic nitrogen contained in the wastewater itself or generated by the degradation of organic matter will cause the total nitrogen in the effluent to not meet the standard. Therefore, it is necessary to develop a combined chemical wastewater treatment process that can economically and effectively degrade benzene, toluene, aniline and other pollutants in water and reduce the total nitrogen concentration in the effluent, in order to solve the technical problems in the above wastewater purification treatment process. Summary of the Invention

[0006] To solve the problems that the cost of completely degrading benzene, toluene, and aniline pollutants in chemical industrial wastewater by the existing ozone advanced oxidation technology is too high, and the total nitrogen concentration in the effluent cannot meet the discharge standard, the present invention provides a method for coupling an autotrophic denitrifying microbial reactor to improve the total nitrogen removal rate of the effluent of the ozone advanced oxidation wastewater treatment process. In the method of the present invention, by optimizing the treatment parameters of the ozone advanced oxidation technology, the effluent containing a large amount of nitrogen and a small amount of organic matter, together with other wastewater containing a large amount of ammonia nitrogen from the outside, is jointly introduced into the autotrophic denitrifying microbial reactor, achieving the effect of economically, efficiently, and up-to-standard treating chemical industrial wastewater.

[0007] The purpose of the present invention is to provide a method for coupling an autotrophic denitrifying microbial reactor to improve the total nitrogen removal rate of the effluent of the ozone advanced oxidation wastewater treatment process, including the following steps:

[0008] S1. Adjust the pH value of the wastewater containing aromatic organic pollutants to 6.0 - 7.0, introduce it into the reactor, and continuously introduce ozone using an ozone generator.

[0009] S2. Add a hydrogen peroxide solution at regular intervals, continuously stir and control the reaction temperature, detect the concentration of aromatic organic pollutants in the wastewater. When the total concentration of aromatic organic pollutants in the wastewater is reduced to 6 mg / L, detect the turbidity value of the effluent, add a flocculant, and let it stand.

[0010] S3. Introduce the effluent obtained in step S2 into an EGSB anaerobic biological reactor, and at the same time introduce the wastewater containing ammonia nitrogen into the EGSB anaerobic biological reactor. The EGSB anaerobic biological reactor contains a short-cut denitrifying bacterial community and an anaerobic ammonium oxidation bacterial community. After the wastewater is treated up to standard in the EGSB anaerobic biological reactor, it is discharged.

[0011] In some embodiments of the present invention, in step S1, the aromatic organic pollutants include one or more of benzene, toluene, and aniline.

[0012] In some embodiments of the present invention, in step S1, the pH value regulator is a dilute hydrochloric acid solution or a sodium hydroxide solution; the rate of introducing ozone is 30 - 60 mL / min. -1 The concentration of the dilute hydrochloric acid solution is not higher than 10 mol / L.

[0013] Further, the rate of ozone, by way of example, can be 30 mL / min, 35 mL / min, 40 mL / min, 45 mL / min, 50 mL / min, 55 mL / min, 60 mL / min, etc., or any value within any interval between any two values.

[0014] Further, the pH value is adjusted to 6.5 - 7.0. Exemplarily, it can be 6.5, 6.6, 6.7, 6.8, 6.9, 7, etc., or any interval value between any two numerical values.

[0015] In some embodiments of the present invention, in step S2, the concentration of hydrogen peroxide is 10 - 40 mg / L. Exemplarily, it can be 10 mg / L, 15 mg / L, 20 mg / L, 25 mg / L, 30 mg / L, 35 mg / L, 40 mg / L, etc., or any interval value between any two numerical values.

[0016] In some embodiments of the present invention, in step S2, the flocculant is polyferric chloride and / or polyferric sulfate.

[0017] In some embodiments of the present invention, in step S2, the fixed time interval is 15 - 22 min.

[0018] In some embodiments of the present invention, in step S2, the detection interval time is 15 - 22 min.

[0019] In some embodiments of the present invention, in step S2, when the turbidity value of the effluent is greater than 20 NTU, 2 - 10 g of flocculant is added to every 8 liters of wastewater; when the turbidity value is less than 20 NTU, 0.2 - 2 g of flocculant is added to every 8 liters of wastewater.

[0020] Further, in step S2, when the turbidity value is greater than 20 NTU, 3 - 6 g of flocculant is added to every 8 liters of wastewater; when the turbidity value is less than 20 NTU, 1 - 2 g of flocculant is added to every 8 liters of wastewater.

[0021] In some embodiments of the present invention, in step S3, the ammonia nitrogen concentration is 10 - 200 mg / L. Exemplarily, it can be 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200 mg / L, etc., or any interval value between any two numerical values.

[0022] In some embodiments of the present invention, in step S3, for the short - cut denitrifying bacteria group and anaerobic ammonia - oxidizing bacteria group: the concentrations of their mixed liquor suspended solids (MLSS) and mixed liquor volatile suspended solids (MLVSS) are 8.0 - 10.0 g / L and 5.5 - 7.5 g / L respectively.

[0023] In some embodiments of the present invention, in step S3, the total influent flow rate of the EGSB anaerobic bioreactor is 1 - 2 L / h, the reflux ratio is 2 - 6, the hydraulic retention time is 4 - 12 h, and the reaction temperature is 28 - 35 °C.

[0024] In the present invention, hydroxyl radicals generated by ozone and hydrogen peroxide in water can oxidize and degrade organic pollutants such as benzene, toluene, and aniline, and at the same time, partially oxidize nitrite present in the wastewater to NO 3- . By adjusting the parameters of the advanced oxidation process, the amount of added hydrogen peroxide can be saved, making the wastewater treatment process more economical; at the same time, a flocculant is added to improve the biodegradability of the effluent. The effluent after the advanced oxidation process contains a small amount of organic matter and a large amount of nitrogen. After the effluent is introduced into the EGSB anaerobic bioreactor, the short-range denitrifying bacteria use the small amount of organic matter in the wastewater to reduce nitrate nitrogen to nitrite nitrogen, while the anaerobic ammonium oxidation bacteria use the ammonia nitrogen introduced from the outside as an electron donor and nitrite nitrogen as an electron acceptor for nitrogen removal.

[0025] The above technical solutions of the present invention have the following advantages compared with the prior art:

[0026] 1. The present invention can use advanced oxidation technology to degrade organic wastewater containing benzene ring pollutants. The biodegradability of the treated wastewater is greatly enhanced. At the same time, by adjusting the process parameters and coupling with an anaerobic ammonium oxidation reactor, it overcomes the problems that the cost of completely degrading benzene ring pollutants in chemical industrial wastewater by ozone advanced oxidation technology is too high and the total nitrogen concentration of the effluent cannot meet the discharge standards.

[0027] 2. The present invention can not only greatly reduce the cost of completely degrading benzene ring pollutants in chemical industrial wastewater by ozone advanced oxidation technology, but also the effluent is treated with a short-range denitrification coupled with an anaerobic ammonium oxidation EGSB bioreactor, reducing the carbon source required in the denitrification process of the traditional denitrification and nitrogen removal process, achieving the effect of economically, efficiently and meeting the standards in treating chemical industrial wastewater. Description of the Drawings

[0028] In order to make the content of the present invention easier to be clearly understood, the following further details the present invention according to specific embodiments of the present invention and in combination with the drawings, wherein,

[0029] Figure 1 is the structural diagram of the SBR reactor coupled with the EGSB anaerobic bioreactor used in the embodiment of the present invention. Among them, S1 is the first water inlet tank, S2 is the first water inlet pump, S3 is the oxygen cylinder, S4 is the ozone generator, S5 is the stirring paddle, S6, S7, S8, S9 are the first drain valves, S10 is the drain pump, E1 and E2 are the second water inlet tanks, E3 and E4 are the second water inlet pumps, E5 is the anaerobic bioreactor, E6 is the water bath temperature control device, E7 is the water outlet tank, E51 is the raw water mixing chamber, E52 is the reaction chamber, E53 is the internal water reflux pump, E54 is the second drain valve, E55 is the three-phase separator, and E56 is the DO and pH monitoring port.

[0030] Figure 2It is the benzene removal effect diagram in Example 1.

[0031] Figure 3 It is the toluene removal effect diagram in Example 1.

[0032] Figure 4 It is the phenol removal effect diagram in Example 1.

[0033] Figure 5 It is the nitrogen removal effect diagram in Example 1. Detailed implementation manners

[0034] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments, so that those skilled in the art can better understand the present invention and be able to implement it, but the exemplified embodiments are not used as a limitation to the present invention.

[0035] The present invention can use a conventional plexiglass reactor in the art.

[0036] Specifically, the structure of the SBR reactor coupled with the EGSB anaerobic bioreactor used in the following examples is as Figure 1 shown. The device on the left includes a first water inlet tank S1, a first water inlet pump S2, an oxygen cylinder S3, an ozone generator S4, a stirring paddle S5, a first drain valve S6, S7, S8, S9, and a drain pump S10.

[0037] The device on the right includes second water inlet tanks E1 and E2, second water inlet pumps E3 and E4, an EGSB anaerobic bioreactor E5, a constant temperature water bath E6, and an outlet water tank E7; a water bath heat preservation layer is provided on the outer layer of the anaerobic bioreactor, a water bath temperature control device E6, and an outlet water tank E7; a water bath heat preservation structure is provided on the outer layer of the anaerobic bioreactor, and the water outlet of the water bath temperature control device E6 is sent to the water bath heat preservation structure through a circulation pump E61, heated and refluxed to the water bath temperature control device E6; a raw water mixing chamber E51, a reaction chamber E52, an internal water reflux pump E53, a drain valve E54, a three-phase separator E55, a DO and pH monitoring port E56 are provided inside the anaerobic bioreactor.

[0038] This device includes an SBR reactor and an EGSB anaerobic bioreactor coupled with the SBR generator.

[0039] Specifically, a first water inlet is provided on one side of the SBR reactor. The first water inlet is connected to the first water inlet tank S1. The first water inlet tank S1 pumps the wastewater into the SBR reactor through the first water inlet pump S2. A plurality of first drain valves are provided on the other side of the SBR reactor. For example, there can be four first drain valves, namely S6, S7, S8, and S9, which are distributed along the height direction of the SBR reactor. The top of the SBR reactor is connected to an air inlet pipe. One end of the air inlet pipe extends into the bottom of the SBR reactor, and the other end of the air inlet pipe is connected to an ozone generator S4. The ozone generator S4 is connected to an oxygen cylinder S3. The oxygen in the oxygen cylinder S3 forms ozone through the ozone generator S4 and then enters the SBR reactor through the air inlet pipe. Preferably, a stirring paddle S5 is also connected to the top of the SBR reactor. After being treated by the SBR reactor, the wastewater passes through any one of the first drain valves S6, S7, S8, and S9 and then enters the second water inlet tank through a drain pump S10. For example, the second water inlet tank can be set as two, namely the second water inlet tanks E1 and E2. The second water inlet tanks E1 and E2 are respectively connected to second water inlet pumps E3 and E4. The wastewater treated by the SBR reactor is stored in the second water inlet tanks E1 and E2, and then the second water inlet pumps E3 and E4 pump the wastewater into the EGSB anaerobic biological reactor.

[0040] The EGSB anaerobic biological reactor includes a reactor body and a water bath heat preservation structure provided on the outer periphery of the reactor body. The water bath heat preservation structure is connected to a water bath temperature control device E6. An outlet is provided at the top of the water bath heat preservation structure, and a second water inlet is provided at the bottom. The cold water in the water bath heat preservation structure enters the water bath temperature control device E6 through the outlet. The water bath temperature control device E6 heats the cold water to form hot water, and the hot water enters the water bath heat preservation structure through a circulation pump E61 and the second water inlet at the bottom in sequence, so as to realize the heat preservation of the EGSB anaerobic biological reactor. The reactor body is respectively provided with a raw water mixing chamber E51, a reaction chamber E52, and a three-phase separator E55 from bottom to top. The bottom of the raw water mixing chamber E51 is connected to the second water inlet tanks E1 and E2. The reaction chamber E52 is filled with denitrifying granular sludge coupled with anaerobic ammonium oxidation granular sludge. DO and pH monitoring ports E56 are provided at the top of the three-phase separator E55. One side of the three-phase separator E55 is also connected to a water outlet tank E7. A return water outlet is also provided on one side of the reactor body close to the three-phase separator E55. The water is pumped into the bottom of the raw water mixing chamber E51 again through the return water outlet and an internal water return pump E53. Preferably, at least one second drain valve E54 is also provided on the reactor body.

[0041] Example 1

[0042] This example provides a method for improving the total nitrogen removal rate of the effluent of an ozone advanced oxidation wastewater treatment process by a coupled autotrophic denitrifying microbial reactor, including the following steps:

[0043] S1. Take the wastewater containing 30 mg / L benzene, 30 mg / L toluene and 30 mg / L aniline simultaneously. Introduce 8 L of the wastewater into an SBR reactor with a total reaction volume of 8.5 L. Add 1 mol / L hydrochloric acid to adjust the pH to 6.8 - 7.0. Open the oxygen cylinder and ozone generator, continuously introduce ozone into the water at a rate of 50 mL / min. Add 30 mL of 50% hydrogen peroxide solution every 20 minutes, continuously stir and control the reaction temperature. Take samples from the reactor every 20 minutes and measure the concentrations of benzene, toluene and aniline in the wastewater respectively.

[0044] S2. When the total concentration of benzene, toluene and aniline in the sampled wastewater is reduced to 6 mg / L and the measured turbidity value is 23 NTU, add 6 g of the flocculant polyferric chloride, stir and then precipitate for 20 min. The effluent is stored in the influent tank E1 of the EGSB anaerobic bioreactor.

[0045] S3. Open the inlet pumps E3 and E4, and continuously feed the advanced oxidation process-treated effluent stored in the influent tank E1 of the EGSB anaerobic bioreactor and the wastewater containing 50 mg / L ammonia nitrogen in the influent tank E2 at a 1:1 inlet flow rate and a total inlet flow rate of 2 L / h. Set the reflux ratio to 6 and the hydraulic retention time to 12 hours. Open the water bath temperature control device E6 and the circulation pump E61 to control the reaction temperature of the reactor at 32 °C.

[0046] The wastewater is treated by an EGSB anaerobic bioreactor containing short-cut denitrifying bacteria and anaerobic ammonia-oxidizing bacteria (the concentrations of its mixed liquor suspended solids (MLSS) and mixed liquor volatile suspended solids (MLVSS) are 9.3 g / L and 6.5 g / L respectively). After monitoring and meeting the standards, it is discharged.

[0047] Example 2

[0048] This example is basically the same as Example 1, except that in this example, the rate of adding ozone in step S1 is 30 mL / min.

[0049] Example 3

[0050] This example is basically the same as Example 1, except that in this example, the rate of adding ozone in step S1 is 40 mL / min.

[0051] Example 4

[0052] This example is basically the same as Example 1, except that in this example, the flocculant used in step S2 is polyferric sulfate.

[0053] Example 5

[0054] This embodiment is basically the same as Embodiment 1, except that in this embodiment, when the measured turbidity value in step S2 is 23 NTU, 2 g of the flocculant polyferric chloride is added.

[0055] Embodiment 6

[0056] This embodiment is basically the same as Embodiment 1, except that in this embodiment, when the measured turbidity value in step S2 is 23 NTU, 4 g of the flocculant polyferric chloride is added.

[0057] Embodiment 7

[0058] This embodiment is basically the same as Embodiment 1, except that in this embodiment, when the measured turbidity value in step S2 is 23 NTU, 8 g of the flocculant polyferric chloride is added.

[0059] Embodiment 8

[0060] This embodiment is basically the same as Embodiment 1, except that in this embodiment, in step S3, the concentration of ammonia-nitrogen-containing wastewater in the inlet water tank of the EGSB anaerobic bioreactor E2 is 40 mg / L.

[0061] Embodiment 9

[0062] This embodiment is basically the same as Embodiment 1, except that in this embodiment, in step S3, the concentration of ammonia-nitrogen-containing wastewater in the inlet water tank of the EGSB anaerobic bioreactor E2 is 45 mg / L.

[0063] Embodiment 10

[0064] This embodiment is basically the same as Embodiment 1, except that in this embodiment, in step S3, the concentration of ammonia-nitrogen-containing wastewater in the inlet water tank of the EGSB anaerobic bioreactor E2 is 55 mg / L.

[0065] Embodiment 11

[0066] This embodiment is basically the same as Embodiment 1, except that in this embodiment, in step S3, the concentration of ammonia-nitrogen-containing wastewater in the inlet water tank of the EGSB anaerobic bioreactor E2 is 60 mg / L.

[0067] Comparative Example 1

[0068] This comparative example provides a method for improving the total nitrogen removal rate of the effluent of an ozone advanced oxidation wastewater treatment process by coupling an autotrophic denitrifying microbial reactor, including the following steps:

[0069] S1. Take wastewater containing 30 mg / L of benzene, 30 mg / L of toluene, and 30 mg / L of aniline at the same time, and store it in the inlet water tank E1 of the EGSB anaerobic bioreactor.

[0070] S2. Turn on the inlet pumps E3 and E4, and continuously feed the wastewater stored in the inlet water tank E1 of the EGSB anaerobic bioreactor and the wastewater containing 50 mg / L ammonia nitrogen in the inlet water tank E2 at a 1:1 inlet water flow rate with a total inlet water flow rate of 2 L / h. Set the reflux ratio to 6 and the hydraulic retention time to 12 hours; turn on the water bath temperature control device E6 and the circulation pump E61 to control the reaction temperature of the reactor at 32°C.

[0071] Comparative Example 2

[0072] This comparative example provides a method for improving the total nitrogen removal rate of the effluent of the ozone advanced oxidation wastewater treatment process by coupling an autotrophic denitrifying microorganism reactor, including the following steps:

[0073] S1. Take wastewater containing 30 mg / L benzene, 30 mg / L toluene, and 30 mg / L aniline simultaneously. Introduce 8 L of the wastewater into an SBR reactor with a total reaction volume of 8.5 L, add 1 mol / L hydrochloric acid to adjust the pH to 6.8 - 7.0, turn on the oxygen cylinder and the ozone generator, continuously introduce ozone into the water at a rate of 50 mL / min, add 30 mL of hydrogen peroxide solution every 20 minutes, continuously stir and control the reaction temperature; draw samples from the reactor every 20 minutes and measure the concentrations of benzene, toluene, and aniline in the wastewater respectively.

[0074] S2. When the total concentration of benzene, toluene, and aniline in the sampled wastewater is reduced to 6 mg / L, add 6 g of the flocculant polyferric chloride, stir and precipitate for 20 minutes, and discharge the effluent to the inlet water tank E1 of the EGSB anaerobic bioreactor.

[0075] S3. Turn on the inlet pumps E3 and E4, and feed the advanced oxidation process treated effluent stored in the inlet water tank E1 of the EGSB anaerobic bioreactor and the wastewater containing 50 mg / L ammonia nitrogen in the inlet water tank E2 into an empty EGS reactor without anaerobic denitrifying microorganisms at a 1:1 inlet water flow rate with a total inlet water flow rate of 2 L / h for continuous feeding. Set the reflux ratio to 6 and the hydraulic retention time to 12 hours; turn on the water bath temperature control device E6 and the circulation pump E61 to control the reaction temperature of the reactor at 32°C.

[0076] Comparative Example 3

[0077] This comparative example is basically the same as Example 1, except that in this example, 30 mL of hydrogen peroxide solution is added every 25 minutes in step S1.

[0078] Comparative Example 4

[0079] This comparative example is basically the same as Example 1, except that in this example, 30 mL of hydrogen peroxide solution is added every 30 minutes in step S1.

[0080] Test

[0081] According to "Methods for Monitoring Water and Wastewater" (Fourth Edition, compiled by the Editorial Committee for Methods for Monitoring Water and Wastewater of the State Environmental Protection Administration), turbidity was monitored using the portable turbidimeter method, ammonia nitrogen was monitored using the Nessler's reagent photometry method, and total nitrogen was monitored using the potassium persulfate oxidation ultraviolet spectrophotometry method; the concentrations of benzene and toluene were monitored by referring to the method in the national standard "Standard Methods for Hygienic Examination of Benzene Series in Source Water - Gas Chromatography" (GB / T 11937-1989); the concentration of aniline was monitored by referring to the method in the environmental standard "Determination of Aniline Compounds in Water Quality - Gas Chromatography-Mass Spectrometry" (HJ 822-2017). The test results are shown in Figures 2 to 5 。

[0082] Among them, Figures 2 to 4 are respectively the removal effect diagrams of benzene, toluene and aniline in Example 1. It can be seen from the figure that the concentrations of organic pollutants in the influent water are all 30 mg / L. After treatment by the advanced oxidation process, the concentrations of the three organic pollutants in the effluent water are all at a relatively low level, and the total concentration of the final effluent is less than 6 mg / L.

[0083] Figure 5 is the removal effect diagram of nitrogen in Example 1. It can be seen from the figure that after treatment by the short-cut denitrification coupled with anaerobic ammonium oxidation EGSB anaerobic bioreactor, the ammonia nitrogen concentration in the effluent water is less than 8 mg / L, and the total nitrogen concentration is less than 20 mg / L.

[0084] Figures 2 to 5 The results show that the wastewater treated in Example 1 can meet the discharge standards in "Discharge Standards for Pollutants from Municipal Wastewater Treatment Plants" (GB18918-2002). The concentrations of organic pollutants, ammonia nitrogen and total nitrogen in the wastewater treated in Examples 2-6 are basically the same as those in Example 1, but the fluctuation range of the effluent pollutants is relatively large. The ammonia nitrogen concentration in Examples 2 and 3 is sometimes greater than 8 mg / L; the total nitrogen concentration in Comparative Examples 3 and 4 is sometimes greater than 20 mg / L, and it cannot stably meet the first-class B discharge standards in "Discharge Standards for Pollutants from Municipal Wastewater Treatment Plants" (GB18918-2002).

[0085] In Comparative Example 1, since the advanced oxidation technology was not used to treat organic pollutants, the concentrations of organic pollutants, ammonia nitrogen and total nitrogen in the wastewater were relatively high, and the total nitrogen concentration was greater than 30 mg / L. The treated effluent could not meet the first-class B discharge standards in "Discharge Standards for Pollutants from Municipal Wastewater Treatment Plants" (GB18918-2002).

[0086] After treating organic pollutants using advanced oxidation technology in Comparative Example 2, since the effluent was not denitrified by the microorganisms in the EGSB anaerobic bioreactor, the nitrogen and total nitrogen concentrations in the treated effluent were relatively high, with the total nitrogen concentration being greater than 30 mg / L, and it was unable to meet the Class B criteria of the Discharge Standard of Pollutants for Municipal Wastewater Treatment Plants (GB 18918-2002).

[0087] Obviously, the above examples are merely illustrations given for clarity and are not limitations on the implementation manners. For those of ordinary skill in the art, other different forms of changes or alterations can be made based on the above description. It is not necessary and impossible to enumerate all implementation manners here. And the obvious changes or alterations derived therefrom still fall within the protection scope of this invention.

Claims

1. A method for improving the total nitrogen removal rate of effluent from an ozone advanced oxidation wastewater treatment process by coupling an autotrophic denitrification microbial reactor, characterized in that: The following steps are involved: S1. Adjust the pH value of the wastewater containing aromatic organic pollutants to 6.0-7.0, enter the reactor, and continuously introduce ozone using an ozone generator; S2. Add hydrogen peroxide solution at regular intervals, continue stirring and control the reaction temperature, detect the concentration of aromatic organic pollutants in the wastewater, and when the total concentration of aromatic organic pollutants in the wastewater is reduced to 6 mg / L, detect the turbidity value of the effluent, add flocculant, and let it stand; S3, introducing the water obtained in step S2 into the EGSB anaerobic bioreactor, and at the same time introducing the wastewater containing ammonia nitrogen into the EGSB anaerobic bioreactor, the EGSB anaerobic bioreactor contains short-range denitrifying bacteria and anaerobic ammonia oxidizing bacteria, and the wastewater is discharged after being treated by the EGSB anaerobic bioreactor and meeting the standards.

2. The method according to claim 1, characterized in that In step S1, the aromatic organic pollutants include one or more of benzene, toluene, and aniline.

3. The method according to claim 1, characterized in that In step S1, the pH regulator is a dilute hydrochloric acid solution or a sodium hydroxide solution; and the rate of adding ozone is 30 to 60 mL / min.

4. The method according to claim 1, characterized in that: In step S2, the concentration of hydrogen peroxide is 10 to 40 mg / L.

5. The method according to claim 1, characterized in that In step S2, the flocculant is polyferric chloride and / or polyferric sulfate.

6. The method according to claim 1, characterized in that In step S2, the certain interval time is 15 to 22 minutes.

7. The method according to claim 1, characterized in that In step S2, the reaction temperature is 25-40°C.

8. The method according to claim 1, characterized in that In step S2, when the turbidity value of the effluent is greater than 20 NTU, 2 to 10 g of flocculant is added to every 8 liters of wastewater, and when the turbidity value is less than 20 NTU, 0.2 to 2 g of flocculant is added to every 8 liters of wastewater.

9. The method according to claim 1, characterized in that: In step S3, the ammonia nitrogen concentration is 10-200 mg / L.

10. The method according to claim 1, characterized in that In step S3, the total water inflow rate of the EGSB anaerobic bioreactor is 1-2 L / h, the reflux ratio is 2-6, the hydraulic retention time is 4-12 h, and the reaction temperature is 28-35°C.

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