A method of sewage treatment

Abstract

The present application relates to sewage treatment technical field, especially to a kind of sewage treatment method, the system along the direction of water flow successively includes EGSB anaerobic reactor and OAO pure membrane biological pool;The OAO pure membrane biological pool along the direction of water flow successively includes first aerobic zone, anoxic zone and second aerobic zone;The first aerobic zone is provided with MABR component;The anoxic zone is provided with A type MBBR filler;The second aerobic zone is provided with B type MBBR filler;Treatment method includes: A) sewage is treated anaerobically in EGSB anaerobic reactor;B) transported to first aerobic zone and carried out simultaneous nitrification and anaerobic ammonia oxidation reaction;C) transported to anoxic zone and carried out anaerobic ammonia oxidation reaction;D) transported to second aerobic zone and carried out nitrification, obtain treated water body.The present application can realize the efficient autotrophic denitrification of sewage, significantly reduce the energy consumption of sewage treatment process.

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment technology, and in particular to a wastewater treatment method. Background Technology

[0002] Municipal wastewater treatment plants widely employ biological processes, relying on microorganisms to remove organic matter, nitrogen, and phosphorus from wastewater. However, traditional nitrification / denitrification processes suffer from high aeration energy consumption, large external carbon source dosages, and significant sludge production. Reducing energy consumption in wastewater treatment, promoting energy self-sufficiency, and achieving energy and resource recovery from wastewater represent new directions for wastewater treatment plant development. Summary of the Invention

[0003] In view of this, the technical problem to be solved by the present invention is to provide a wastewater treatment method that can achieve efficient autotrophic denitrification of wastewater and significantly reduce the energy consumption of the wastewater treatment process.

[0004] This invention provides a wastewater treatment method, wherein the system comprises, in sequence along the direction of water flow, an EGSB anaerobic reactor and an OAO pure membrane biological tank;

[0005] The OAO pure membrane biological tank includes, along the direction of water flow, a first aerobic zone, an anoxic zone, and a second aerobic zone; the second aerobic zone is equipped with an outlet.

[0006] The first aerobic zone is equipped with a MABR component;

[0007] The anoxic zone is equipped with type A MBBR packing.

[0008] The second aerobic zone is equipped with type B MBBR packing material;

[0009] The processing method includes the following steps:

[0010] A) Anaerobic treatment of wastewater in an EGSB anaerobic reactor;

[0011] B) The anaerobic wastewater is transported to the first aerobic zone for simultaneous nitrification and anaerobic ammonium oxidation reactions;

[0012] C) The wastewater after the reaction is transported to an anoxic zone for anaerobic ammonia oxidation reaction;

[0013] D) The wastewater after the reaction in step C) is transported to the second aerobic zone for nitrification to obtain treated water.

[0014] Preferably, the EGSB anaerobic reactor is equipped with anaerobic granular sludge, and the methanogenic activity of the anaerobic granular sludge in the EGSB anaerobic reactor is greater than 0.31 kg COD / kg VSS·d;

[0015] The EGSB anaerobic reactor has an organic loading of 2–6 kg COD / (m³) at room temperature. 3 ·d).

[0016] Preferably, an inlet is provided at the bottom of the EGSB anaerobic reactor;

[0017] A biogas outlet is provided at the top of the EGSB anaerobic reactor.

[0018] Preferably, in the first aerobic zone, the volume percentage of the MABR component is 45% to 55%;

[0019] A first submersible mixer is installed at the bottom of the first aerobic zone.

[0020] Preferably, in the anoxic zone, type A MBBR packing is suspended, the filling ratio of type A MBBR packing is 30% to 50%, the diameter of type A MBBR packing is 18 to 22 mm, the thickness is 4 to 6 mm, and the middle is porous;

[0021] A second submersible mixer is installed at the bottom of the oxygen-deficient zone.

[0022] Preferably, in the second aerobic zone, the B-type MBBR packing is suspended, the packing ratio of the B-type MBBR packing is 30% to 50%, the diameter of the B-type MBBR packing is 8 to 12 mm, the thickness is 4 to 6 mm, and the middle is porous;

[0023] A third submersible mixer is installed at the bottom of the second aerobic zone.

[0024] Preferably, the concentration of anaerobic granular sludge in the anaerobic EGSB reactor is 10-25 g / L, and the hydraulic retention time is controlled at 3-15 h.

[0025] The effluent C / N ratio of the anaerobic EGSB reactor is 1 to 2.

[0026] Preferably, the hydraulic retention time of the first aerobic zone is controlled at 2 to 5 hours, and the dissolved oxygen in the water is controlled at below 0.5 mg / L.

[0027] Preferably, the hydraulic retention time in the anoxic zone is controlled to be 1 to 2 hours.

[0028] Preferably, the hydraulic retention time in the second aerobic zone is controlled at 1 to 2 hours, and the dissolved oxygen in the water is controlled at 3 mg / L or higher.

[0029] This invention provides a wastewater treatment method. The system comprises, along the direction of water flow, an EGSB anaerobic reactor and an OAO pure membrane biological tank. The OAO pure membrane biological tank comprises, along the direction of water flow, a first aerobic zone, an anoxic zone, and a second aerobic zone. The second aerobic zone is provided with an outlet. The first aerobic zone is provided with an MABR module. The anoxic zone is provided with type A MBBR packing. The second aerobic zone is provided with type B MBBR packing. The treatment method includes the following steps: A) anaerobic treatment of wastewater in the EGSB anaerobic reactor; B) conveying the anaerobic treated wastewater to the first aerobic zone for simultaneous nitrification and anaerobic ammonia oxidation reactions; C) conveying the reacted wastewater to the anoxic zone for anaerobic ammonia oxidation reaction; D) conveying the wastewater from step C) to the second aerobic zone for nitrification reaction, thereby obtaining treated water. This invention utilizes an EGSB anaerobic reactor to recover energy resources. By combining two biofilms, MABR and MBBR, it fully leverages the advantages of MABR's efficient oxygen supply and precise oxygen control, forming the basis for the system's stable autotrophic denitrification under pure membrane conditions. Furthermore, by combining the simple operation of MBBR suspended packing material, and enriching anaerobic ammonia-oxidizing bacteria and nitrifying bacteria in stages, it significantly improves the system's denitrification rate and stability. Simultaneously, the energy consumption during wastewater treatment is low. Attached Figure Description

[0030] Figure 1 A wastewater treatment system diagram provided for one embodiment of the present invention. Detailed Implementation

[0031] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0032] This invention provides a wastewater treatment method, wherein the system comprises, in sequence along the direction of water flow, an EGSB anaerobic reactor and an OAO pure membrane biological tank;

[0033] The OAO pure membrane biological tank includes, along the direction of water flow, a first aerobic zone, an anoxic zone, and a second aerobic zone; the second aerobic zone is equipped with an outlet.

[0034] The first aerobic zone is equipped with a MABR component;

[0035] The anoxic zone is equipped with type A MBBR packing.

[0036] The second aerobic zone is equipped with type B MBBR packing material;

[0037] The processing method includes the following steps:

[0038] A) Anaerobic treatment of wastewater in an EGSB anaerobic reactor;

[0039] B) The anaerobic wastewater is transported to the first aerobic zone for simultaneous nitrification and anaerobic ammonium oxidation reactions;

[0040] C) The wastewater after the reaction is transported to an anoxic zone for anaerobic ammonia oxidation reaction;

[0041] D) The wastewater after the reaction in step C) is transported to the second aerobic zone for nitrification to obtain treated water.

[0042] Figure 1 This is a wastewater treatment system diagram provided according to an embodiment of the present invention. In the diagram, 1 is an EGSB anaerobic reactor, 2 is an OAO pure membrane biological tank, 3 is the first aerobic zone, 4 is the anoxic zone, 5 is the second aerobic zone, 6 is a MABR module, 7 is a type A MBBR packing material, 8 is a type B MBBR packing material, 9 is the first submersible mixer, 10 is the inlet, 11 is the return pipe of the EGSB anaerobic reactor, 12 is the biogas outlet, 13 is anaerobic granular sludge, 14 is the outlet, 15 is the second submersible mixer, and 16 is the third submersible mixer.

[0043] In some embodiments of the present invention, anaerobic granular sludge 13 is provided in the EGSB anaerobic reactor 1, and the methanogenic activity of the anaerobic granular sludge 13 in the EGSB anaerobic reactor is greater than 0.31 kg COD / kg VSS·d, for example 0.35-0.50 kg COD / kg VSS·d or 0.30-0.50 kg COD / kg VSS·d; it can be commercially available.

[0044] In some embodiments of the present invention, the EGSB anaerobic reactor has an organic load of 2–6 kg COD / (m³) at room temperature. 3 ·d), for example, 3-5 kg ​​COD / (m 3 •d) It can rapidly convert organic matter in wastewater into methane to achieve energy recovery.

[0045] In some embodiments of the present invention, an inlet 10 is provided at the bottom of the EGSB anaerobic reactor; and a biogas outlet 12 is provided at the top of the EGSB anaerobic reactor.

[0046] In some embodiments of the present invention, a reflux outlet is provided on the side wall above the anaerobic granular sludge in the EGSB anaerobic reactor, and a reflux inlet is provided on the side wall below the anaerobic granular sludge in the EGSB anaerobic reactor. The pipe between the reflux outlet and the reflux inlet is the reflux pipe 11 of the EGSB anaerobic reactor. By controlling the reflux flow rate, the upward flow velocity in the EGSB reactor can be better controlled, ensuring the fluidization effect of the granular sludge, and thus ensuring the mass transfer efficiency between wastewater and granular sludge.

[0047] The EGSB anaerobic reactor can be commercially available or homemade.

[0048] In this invention, the OAO pure membrane biological tank 2 includes a first aerobic zone 3, an anoxic zone 4, and a second aerobic zone 5 in sequence along the direction of water flow; the second aerobic zone is provided with an outlet 14.

[0049] The first aerobic zone 3 is equipped with an MABR component 6. In some embodiments of the present invention, the volume percentage of the MABR component in the first aerobic zone is 45% to 55%, specifically 50%. The present invention does not impose any special restrictions on the source of the MABR component, and it can be commercially available.

[0050] In some embodiments of the present invention, a first submersible agitator 9 is provided at the bottom of the first aerobic zone. This can be a commercially available submersible agitator.

[0051] In the first aerobic zone, relying on the unique membrane aeration characteristics of MABR, the dissolved oxygen is precisely controlled. Various denitrifying bacteria, including nitrifying bacteria, anaerobic ammonia oxidizing bacteria and denitrifying bacteria, are enriched in layers on the surface of its membrane fibers, realizing simultaneous short-range nitrification, anaerobic ammonia oxidation and autotrophic denitrification.

[0052] The anoxic zone 4 is equipped with type A MBBR packing material 7. In some embodiments of the present invention, the type A MBBR packing material is made of high-density polyethylene, and its surface is enriched with anaerobic ammonia-oxidizing bacteria, which are responsible for converting the nitrite and residual ammonia nitrogen accumulated in the aerobic zone of the MABR into nitrogen gas through anaerobic ammonia oxidation. The present invention does not have any special restrictions on the source of the type A MBBR packing material, and it can be commercially available.

[0053] In some embodiments of the present invention, in the anoxic zone, type A MBBR packing is suspended, and the filling ratio of type A MBBR packing is 30% to 50%, for example, 50%; the diameter of type A MBBR packing is 18 to 22 mm, the thickness is 4 to 6 mm, and the middle is porous.

[0054] In some embodiments of the present invention, a second submersible agitator 15 is provided at the bottom of the hypoxic zone. This can be a commercially available submersible agitator.

[0055] The second aerobic zone 5 is equipped with type B MBBR packing material 8. In some embodiments of the present invention, the type B MBBR packing material is made of high-density polyethylene. Compared with type A MBBR packing material, the type B MBBR packing material has a larger specific surface area and is enriched with nitrifying bacteria, which are responsible for converting all the remaining ammonia nitrogen in the wastewater into nitrate, ensuring the ammonia nitrogen removal rate. The present invention does not have any special restrictions on the source of the type B MBBR packing material and it can be commercially available.

[0056] In some embodiments of the present invention, in the second aerobic zone, type B MBBR packing is suspended, and the packing ratio of type B MBBR packing is 30% to 50%, for example, 40%; the diameter of type B MBBR packing is 8 to 12 mm, the thickness is 4 to 6 mm, and the middle is porous.

[0057] In some embodiments of the present invention, a third submersible mixer 16 is provided at the bottom of the second aerobic zone. This can be a commercially available submersible mixer.

[0058] In some embodiments of the present invention, an outlet 14 is provided at the upper part of the second aerobic zone.

[0059] In step A):

[0060] Wastewater is anaerobicly treated in an EGSB anaerobic reactor.

[0061] In some embodiments of the present invention, the wastewater contains NH3-N at a concentration of 22.0–56.8 mg / L; TN at a concentration of 30.5–68.7 mg / L; BOD at a concentration of 110.0–142 mg / L; COD at a concentration of 152.0–436.0 mg / L; and TP at a concentration of 3.02–7.36 mg / L.

[0062] In some embodiments of the present invention, the temperature of the wastewater is 20-25°C.

[0063] In some embodiments of the present invention, the concentration of anaerobic granular sludge in the anaerobic EGSB reactor is 10-25 g / L, such as 20 g / L or 10 g / L; the hydraulic retention time is controlled at 3-15 h, such as 6 h or 4 h, depending on the concentration of organic matter in the influent and the temperature; and the C / N ratio of the effluent from the anaerobic EGSB reactor is 1-2, such as 1.3-1.8, 1.5-1.8, or 1.5-2.0.

[0064] In step B):

[0065] The anaerobic wastewater is transported to the first aerobic zone for simultaneous nitrification and anaerobic ammonia oxidation reactions.

[0066] In some embodiments of the present invention, the hydraulic retention time of the first aerobic zone is controlled to be 2–5 hours, such as 4 hours or 2 hours, depending on the changes in water temperature and influent ammonia nitrogen concentration. The MABR uses membrane aeration to supply oxygen, and the dissolved oxygen in the water is controlled to be below 0.5 mg / L, such as 0.3–0.5 mg / L or 0.4–0.5 mg / L. Some ammonia nitrogen is removed from the biofilm on the MABR surface through short-cut nitrification / anaerobic ammonia oxidation, while some ammonia nitrogen is converted into nitrite, which enters the anoxic zone along with the remaining ammonia nitrogen.

[0067] In step C):

[0068] The wastewater after the reaction is transported to an anoxic zone for anaerobic ammonia oxidation.

[0069] In some embodiments of the present invention, the hydraulic retention time of the anoxic zone is controlled to be 1-2 hours, for example, 2 hours, depending on the changes in water temperature and substrate concentration. The zone is equipped with type A MBBR packing and a second submersible mixer. The type A MBBR packing has a filling ratio of 30%-50%, a diameter of 20 mm, a thickness of 5 mm, and is porous. Anaerobic ammonia-oxidizing bacteria accumulate on the surface and in the pores of the type A MBBR packing, simultaneously converting nitrite and ammonia nitrogen in the water into nitrogen gas through anaerobic ammonia oxidation, further reducing the total nitrogen in the water.

[0070] In step D):

[0071] The wastewater after the reaction in step C) is transported to the second aerobic zone for nitrification to obtain treated water.

[0072] In some embodiments of the present invention, the hydraulic retention time of the second aerobic zone is controlled at 1-2 hours, for example, 1.5 hours, depending on changes in water temperature and substrate concentration; the dissolved oxygen in the water is controlled at above 3 mg / L. It is equipped with type B MBBR packing and a third submersible agitator, with a packing ratio of 30%-50%. The type B MBBR packing has a diameter of 10 mm and a thickness of 5 mm, and is porous in the middle. Compared with type A MBBR packing, type B MBBR packing has a larger specific surface area, and relies on nitrifying bacteria enriched on its surface to convert all remaining ammonia nitrogen in the wastewater into nitrate, ensuring that the effluent meets standards.

[0073] In this invention, the MABR membrane module is the key to achieving efficient pure membrane autotrophic denitrification. It is the precise control of dissolved oxygen and the anisotropic mass transfer characteristics of the MABR that enable in-situ short-cut nitrification / anaerobic ammonia oxidation. Meanwhile, the remaining nitrite is further removed in the anoxic zone through anaerobic ammonia oxidation. Finally, the nitrification biofilm in the second aerobic zone ensures that the ammonia nitrogen in the effluent meets the standards.

[0074] This invention utilizes an EGSB anaerobic reactor to recover energy materials. By combining two biofilms, MABR and MBBR, it can fully leverage the advantages of MABR in efficient oxygen supply and precise oxygen control, which is the basis for the system to stably achieve autotrophic denitrification under pure membrane conditions. Furthermore, by combining the simple operation characteristics of MBBR suspended packing, it can enrich anaerobic ammonia oxidizing bacteria and nitrifying bacteria in stages, which can significantly improve the system's denitrification rate and system stability.

[0075] This invention employs anaerobic, aerobic, and anoxic treatment in stages, enriching functional bacteria with different physiological characteristics in different devices or areas. This facilitates flexible control of each treatment unit, providing optimal control conditions for each unit and significantly improving the system's treatment efficiency and stability. Compared to traditional nitrification / denitrification wastewater denitrification processes, the OAO pure biofilm system described in this invention does not require internal or external recirculation, is simple in form, and is less affected by low temperatures and more resistant to water quality fluctuations than typical activated sludge systems, resulting in more stable system operation.

[0076] To further illustrate the present invention, the following detailed description of a wastewater treatment method provided by the present invention is provided in conjunction with embodiments, but it should not be construed as limiting the scope of protection of the present invention.

[0077] Example 1

[0078] Adopting such Figure 1 The wastewater treatment system shown is specifically:

[0079] The system includes, in sequence along the direction of water flow, an EGSB anaerobic reactor 1 and an OAO pure membrane biological tank 2;

[0080] The OAO pure membrane biological tank 2 includes, along the direction of water flow, a first aerobic zone 3, an anoxic zone 4, and a second aerobic zone 5.

[0081] Anaerobic granular sludge 13 is provided in the EGSB anaerobic reactor 1. The methanogenic activity of the anaerobic granular sludge 13 in the EGSB anaerobic reactor is 0.35-0.50 kg COD / kg VSS·d. The organic matter loading of the EGSB anaerobic reactor at room temperature is 3-5 kg ​​COD / (m³). 3 ·d);

[0082] An inlet 10 is provided at the bottom of the EGSB anaerobic reactor; a biogas outlet 12 is provided at the top of the EGSB anaerobic reactor.

[0083] A reflux outlet is provided on the side wall above the anaerobic granular sludge in the EGSB anaerobic reactor, and a reflux inlet is provided on the side wall below the anaerobic granular sludge in the EGSB anaerobic reactor. The pipe between the reflux outlet and the reflux inlet is the reflux pipe 11 of the EGSB anaerobic reactor;

[0084] The first aerobic zone 3 is equipped with a MABR component 6; in the first aerobic zone, the volume ratio of the MABR component is 50%;

[0085] A first submersible mixer 9 is installed at the bottom of the first aerobic zone;

[0086] The anoxic zone 4 is equipped with type A MBBR packing material 7; the type A MBBR packing material is made of high-density polyethylene, and its surface is enriched with anaerobic ammonia-oxidizing bacteria, which are responsible for converting the nitrite and residual ammonia nitrogen accumulated in the aerobic zone of the MABR into nitrogen gas through anaerobic ammonia oxidation; in the anoxic zone, the type A MBBR packing material is suspended, and the filling ratio of the type A MBBR packing material is 50%; the diameter of the type A MBBR packing material is 20 mm, the thickness is 5 mm, and the middle is porous; a second submersible agitator 15 is installed at the bottom of the anoxic zone;

[0087] The second aerobic zone 5 is equipped with type B MBBR packing material 8; the type B MBBR packing material is made of high-density polyethylene, and the type B MBBR packing material has a larger specific surface area than the type A MBBR packing material. It is enriched with nitrifying bacteria and is responsible for converting all the remaining ammonia nitrogen in the wastewater into nitrate, ensuring the ammonia nitrogen removal rate; in the second aerobic zone, the type B MBBR packing material is suspended, the packing ratio of the type B MBBR packing material is 40%, the diameter of the type B MBBR packing material is 10 mm, the thickness is 5 mm, and the middle is porous; a third submersible mixer 16 is installed at the bottom of the second aerobic zone;

[0088] The upper part of the second aerobic zone is provided with an outlet 14.

[0089] The method of wastewater treatment using the above-mentioned wastewater treatment system:

[0090] The wastewater being treated is the effluent from the fine screen of a wastewater treatment plant, and its main water quality indicators are as follows: NH3-N 22.0~56.8mg / L; TN 30.5~68.7mg / L; BOD 110.0~142mg / L; COD 152.0~436.0mg / L; TP 3.02~7.36mg / L.

[0091] Under the condition of water temperature of 20-25℃, the hydraulic retention time of EGSB is controlled at 6h, the sludge concentration is 20g / L, and the effluent C / N ratio of the anaerobic EGSB reactor is 1.3-1.8;

[0092] The hydraulic retention time in the first aerobic zone is controlled at 4 hours. The MABR uses membrane aeration to supply oxygen, and the dissolved oxygen in the water is controlled at 0.3-0.5 mg / L.

[0093] The hydraulic retention time in the anoxic zone was controlled to be 2 hours.

[0094] The hydraulic retention time in the second aerobic zone is controlled at 1.5 hours, and the dissolved oxygen is controlled at above 3 mg / L to ensure that all the remaining ammonia nitrogen in the water is converted into nitrate.

[0095] After the system operates under the above control conditions, the effluent quality is as follows: COD: 15~30mg / L, NH4-N<1mg / L, TN<10mg / L.

[0096] Example 2

[0097] Adopting such Figure 1 The wastewater treatment system shown is specifically:

[0098] The system includes, in sequence along the direction of water flow, an EGSB anaerobic reactor 1 and an OAO pure membrane biological tank 2;

[0099] The OAO pure membrane biological tank 2 includes, along the direction of water flow, a first aerobic zone 3, an anoxic zone 4, and a second aerobic zone 5.

[0100] Anaerobic granular sludge 13 is provided in the EGSB anaerobic reactor 1. The methanogenic activity of the anaerobic granular sludge 13 in the EGSB anaerobic reactor is 0.30-0.50 kg COD / kg VSS·d. The organic matter loading of the EGSB anaerobic reactor at room temperature is 3-5 kg ​​COD / (m³). 3 ·d);

[0101] An inlet 10 is provided at the bottom of the EGSB anaerobic reactor; a biogas outlet 12 is provided at the top of the EGSB anaerobic reactor.

[0102] A reflux outlet is provided on the side wall above the anaerobic granular sludge in the EGSB anaerobic reactor, and a reflux inlet is provided on the side wall below the anaerobic granular sludge in the EGSB anaerobic reactor. The pipe between the reflux outlet and the reflux inlet is the reflux pipe 11 of the EGSB anaerobic reactor;

[0103] The first aerobic zone 3 is equipped with a MABR component 6; in the first aerobic zone, the volume ratio of the MABR component is 50%;

[0104] A first submersible mixer 9 is installed at the bottom of the first aerobic zone;

[0105] The anoxic zone 4 is equipped with type A MBBR packing material 7; the type A MBBR packing material is made of high-density polyethylene, and its surface is enriched with anaerobic ammonia-oxidizing bacteria, which are responsible for converting the nitrite and residual ammonia nitrogen accumulated in the aerobic zone of the MABR into nitrogen gas through anaerobic ammonia oxidation; in the anoxic zone, the type A MBBR packing material is suspended, and the filling ratio of the type A MBBR packing material is 50%; the diameter of the type A MBBR packing material is 20 mm, the thickness is 5 mm, and the middle is porous; a second submersible agitator 15 is installed at the bottom of the anoxic zone;

[0106] The second aerobic zone 5 is equipped with type B MBBR packing material 8; the type B MBBR packing material is made of high-density polyethylene, and the type B MBBR packing material has a larger specific surface area than the type A MBBR packing material. It is enriched with nitrifying bacteria and is responsible for converting all the remaining ammonia nitrogen in the wastewater into nitrate, ensuring the ammonia nitrogen removal rate; in the second aerobic zone, the type B MBBR packing material is suspended, the packing ratio of the type B MBBR packing material is 40%, the diameter of the type B MBBR packing material is 10 mm, the thickness is 5 mm, and the middle is porous; a third submersible mixer 16 is installed at the bottom of the second aerobic zone;

[0107] The upper part of the second aerobic zone is provided with an outlet 14.

[0108] The method of wastewater treatment using the above-mentioned wastewater treatment system:

[0109] The wastewater being treated is the effluent from the fine screen of a wastewater treatment plant, and its main water quality indicators are as follows: NH3-N 22.0~56.8mg / L; TN 30.5~68.7mg / L; BOD 110.0~142mg / L; COD 152.0~436.0mg / L; TP 3.02~7.36mg / L.

[0110] Under the condition of water temperature of 20-25℃, the hydraulic retention time of EGSB is controlled at 4h, the sludge concentration is 20g / L, and the effluent C / N ratio of the anaerobic EGSB reactor is 1.5-1.8.

[0111] The hydraulic retention time in the first aerobic zone is controlled at 2 hours. The MABR uses membrane aeration to supply oxygen, and the dissolved oxygen in the water is controlled at 0.4-0.5 mg / L.

[0112] The hydraulic retention time in the anoxic zone was controlled to be 2 hours.

[0113] The hydraulic retention time in the second aerobic zone is controlled at 1.5 hours, and the dissolved oxygen is controlled at above 3 mg / L to ensure that all the remaining ammonia nitrogen in the water is converted into nitrate.

[0114] After operating the system under the above control conditions, the effluent quality is as follows: COD: 15~30mg / L, NH4-N<5mg / L, TN<15mg / L.

[0115] Example 3

[0116] Adopting such Figure 1 The wastewater treatment system shown is specifically:

[0117] The system includes, in sequence along the direction of water flow, an EGSB anaerobic reactor 1 and an OAO pure membrane biological tank 2;

[0118] The OAO pure membrane biological tank 2 includes, along the direction of water flow, a first aerobic zone 3, an anoxic zone 4, and a second aerobic zone 5.

[0119] Anaerobic granular sludge 13 is provided in the EGSB anaerobic reactor 1. The methanogenic activity of the anaerobic granular sludge 13 in the EGSB anaerobic reactor is 0.35-0.50 kg COD / kg VSS·d. The organic matter loading of the EGSB anaerobic reactor at room temperature is 3-5 kg ​​COD / (m³). 3 ·d);

[0120] An inlet 10 is provided at the bottom of the EGSB anaerobic reactor; a biogas outlet 12 is provided at the top of the EGSB anaerobic reactor.

[0121] A reflux outlet is provided on the side wall above the anaerobic granular sludge in the EGSB anaerobic reactor, and a reflux inlet is provided on the side wall below the anaerobic granular sludge in the EGSB anaerobic reactor. The pipe between the reflux outlet and the reflux inlet is the reflux pipe 11 of the EGSB anaerobic reactor;

[0122] The first aerobic zone 3 is equipped with a MABR component 6; in the first aerobic zone, the volume ratio of the MABR component is 50%;

[0123] A first submersible mixer 9 is installed at the bottom of the first aerobic zone;

[0124] The anoxic zone 4 is equipped with type A MBBR packing material 7; the type A MBBR packing material is made of high-density polyethylene, and its surface is enriched with anaerobic ammonia-oxidizing bacteria, which are responsible for converting the nitrite and residual ammonia nitrogen accumulated in the aerobic zone of the MABR into nitrogen gas through anaerobic ammonia oxidation; in the anoxic zone, the type A MBBR packing material is suspended, and the filling ratio of the type A MBBR packing material is 50%; the diameter of the type A MBBR packing material is 20 mm, the thickness is 5 mm, and the middle is porous; a second submersible agitator 15 is installed at the bottom of the anoxic zone;

[0125] The second aerobic zone 5 is equipped with type B MBBR packing material 8; the type B MBBR packing material is made of high-density polyethylene, and the type B MBBR packing material has a larger specific surface area than the type A MBBR packing material. It is enriched with nitrifying bacteria and is responsible for converting all the remaining ammonia nitrogen in the wastewater into nitrate, ensuring the ammonia nitrogen removal rate; in the second aerobic zone, the type B MBBR packing material is suspended, the packing ratio of the type B MBBR packing material is 40%, the diameter of the type B MBBR packing material is 10 mm, the thickness is 5 mm, and the middle is porous; a third submersible mixer 16 is installed at the bottom of the second aerobic zone;

[0126] The upper part of the second aerobic zone is provided with an outlet 14.

[0127] The method of wastewater treatment using the above-mentioned wastewater treatment system:

[0128] The wastewater being treated is the effluent from the fine screen of a wastewater treatment plant, and its main water quality indicators are as follows: NH3-N 22.0~56.8mg / L; TN 30.5~68.7mg / L; BOD 110.0~142mg / L; COD 152.0~436.0mg / L; TP 3.02~7.36mg / L.

[0129] Under the condition of water temperature of 20-25℃, the hydraulic retention time of EGSB is controlled at 4h, the sludge concentration is 10g / L, and the effluent C / N ratio of the anaerobic EGSB reactor is 1.5-2.0;

[0130] The hydraulic retention time in the first aerobic zone is controlled at 4 hours. The MABR uses membrane aeration to supply oxygen, and the dissolved oxygen in the water is controlled at 0.4-0.50 mg / L.

[0131] The hydraulic retention time in the anoxic zone was controlled to be 2 hours.

[0132] The hydraulic retention time in the second aerobic zone is controlled at 1.5 hours, and the dissolved oxygen is controlled at above 3 mg / L to ensure that all the remaining ammonia nitrogen in the water is converted into nitrate.

[0133] After operating the system under the above control conditions, the effluent quality is as follows: COD: 20-30 mg / L, NH4-N < 5 mg / L, TN < 16 mg / L.

[0134] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A wastewater treatment method, wherein the system comprises, in sequence along the direction of water flow, an EGSB anaerobic reactor and an OAO pure membrane biological tank; The OAO pure membrane biological tank includes, along the direction of water flow, a first aerobic zone, an anoxic zone, and a second aerobic zone; the second aerobic zone is equipped with an outlet. The first aerobic zone is equipped with a MABR component; The anoxic zone is equipped with type A MBBR packing; in the anoxic zone, type A MBBR packing is suspended, the filling ratio of type A MBBR packing is 30%~50%, the diameter of type A MBBR packing is 18~22 mm, the thickness is 4~6 mm, and the middle is porous. The second aerobic zone is equipped with type B MBBR packing material; in the second aerobic zone, type B MBBR packing material is suspended, the packing ratio of type B MBBR packing material is 30%~50%, the diameter of type B MBBR packing material is 8~12 mm, the thickness is 4~6 mm, and the middle is porous. The processing method includes the following steps: A) Anaerobic treatment of wastewater in an EGSB anaerobic reactor; The wastewater contained NH3-N at a concentration of 22.0–56.8 mg / L; total nitrogen (TN) at a concentration of 30.5–68.7 mg / L; total oxygen (BOD) at a concentration of 110.0–142 mg / L; total oxygen (COD) at a concentration of 152.0–436.0 mg / L; and total phosphorus (TP) at a concentration of 3.02–7.36 mg / L. B) The anaerobic wastewater is transported to the first aerobic zone for simultaneous nitrification and anaerobic ammonium oxidation reactions; C) The wastewater after the reaction is transported to an anoxic zone for anaerobic ammonia oxidation reaction; The surface of the type A MBBR packing is enriched with anaerobic ammonia-oxidizing bacteria, which are responsible for converting the nitrite and remaining ammonia nitrogen accumulated in the aerobic zone of the MABR into nitrogen gas through anaerobic ammonia oxidation. D) The wastewater after the reaction in step C) is transported to the second aerobic zone for nitrification to obtain treated water; The type B MBBR packing material is enriched with nitrifying bacteria, which are responsible for converting all the remaining ammonia nitrogen in the wastewater into nitrate. This wastewater treatment method achieves highly efficient autotrophic denitrification of wastewater; the OAO pure membrane biological tank system does not require internal or external recirculation.

2. The wastewater treatment method according to claim 1, characterized in that, The EGSB anaerobic reactor is equipped with anaerobic granular sludge, and the methanogenic activity of the anaerobic granular sludge in the EGSB anaerobic reactor is greater than 0.31 kg COD / (kgVSS·d). The EGSB anaerobic reactor has an organic loading of 2-6 kg COD / (m³) at room temperature. 3 ·d).

3. The wastewater treatment method according to claim 1, characterized in that, An inlet is provided at the bottom of the EGSB anaerobic reactor; A biogas outlet is provided at the top of the EGSB anaerobic reactor.

4. The wastewater treatment method according to claim 1, characterized in that, In the first aerobic zone, the volume ratio of the MABR component is 45%~55%; A first submersible mixer is installed at the bottom of the first aerobic zone.

5. The wastewater treatment method according to claim 1, characterized in that, A second submersible mixer is installed at the bottom of the oxygen-deficient zone.

6. The wastewater treatment method according to claim 1, characterized in that, A third submersible mixer is installed at the bottom of the second aerobic zone.

7. The wastewater treatment method according to claim 1, characterized in that, The concentration of anaerobic granular sludge in the EGSB anaerobic reactor is 10~25 g / L, and the hydraulic retention time is controlled at 3~15 h. The effluent C / N ratio of the EGSB anaerobic reactor is 1~2.

8. The wastewater treatment method according to claim 1, characterized in that, The hydraulic retention time in the first aerobic zone is controlled at 2-5 h, and the dissolved oxygen in the water is controlled at below 0.5 mg / L.

9. The wastewater treatment method according to claim 1, characterized in that, The hydraulic retention time in the anoxic zone is controlled to be 1-2 hours.

10. The wastewater treatment method according to claim 1, characterized in that, The hydraulic retention time in the second aerobic zone is controlled at 1-2 hours, and the dissolved oxygen in the water is controlled at 3 mg / L or higher.

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