A nitrogen removal system based on the anammox technology

Abstract

The present invention provides a denitrification system based on the anaerobic ammonium oxidation technology, which includes an anaerobic ammonium oxidation zone, a nitrification and denitrification zone, an alternating current power supply, and two groups of electrode plates. A zwitterionic exchange membrane is arranged between the anaerobic ammonium oxidation zone and the nitrification and denitrification zone; the two groups of electrode plates are respectively arranged in the anaerobic ammonium oxidation zone and the nitrification and denitrification zone and are connected to the alternating current power supply to form an alternating current electric field; nitrification reaction occurs in the nitrification and denitrification zone to generate nitrite nitrogen, and ammonium ions and nitrite ions in the nitrification and denitrification zone enter the anaerobic ammonium oxidation zone through the zwitterionic exchange membrane to carry out anaerobic ammonium oxidation reaction. The nitrate ions generated by anaerobic ammonium oxidation enter the nitrification and denitrification zone through the zwitterionic exchange membrane to carry out denitrification reaction and are reduced to nitrite nitrogen and nitrogen gas, and the denitrification effect is realized through such circulation. Compared with the traditional denitrification process, the present invention has the characteristics of energy saving, carbon saving, and sludge reduction, and has a reasonable design, a simple structure, can achieve efficient denitrification of sewage, and has strong practicability.

Description

Technical Field:

[0001] The present invention belongs to the technical field of nitrogen pollutant treatment, and particularly relates to a denitrification system based on the anaerobic ammonium oxidation technology. Background Art:

[0002] The anaerobic ammonium oxidation process is a biological denitrification technology that uses anaerobic ammonium oxidizing bacteria to directly convert ammonia nitrogen and nitrite nitrogen into nitrogen gas. Compared with the traditional denitrification process, it has the advantages of energy conservation, carbon conservation, and sludge reduction. At present, there are mainly two wastewater treatment processes that apply the anaerobic ammonium oxidation process for denitrification: the partial nitrification-anaerobic ammonium oxidation coupling process (PN / A) and the partial denitrification-anaerobic ammonium oxidation coupling process (DN / A). According to the reactor settings, these two processes can be further divided into one-stage and two-stage processes. The partial nitrification-anaerobic ammonium oxidation coupling process produces nitrite through partial nitrification, which serves as an electron acceptor for the anaerobic ammonium oxidation reaction, and reacts with the ammonia nitrogen in the raw sewage through the anaerobic ammonium oxidation reaction to achieve denitrification. The partial denitrification-anaerobic ammonium oxidation coupling process produces nitrite through partial denitrification, which serves as an electron acceptor for the anaerobic ammonium oxidation reaction, and reacts with the ammonia nitrogen in the raw sewage through the anaerobic ammonium oxidation reaction to achieve denitrification.

[0003] As a strictly anaerobic autotrophic bacterium, the activity and proliferation of anaerobic ammonium oxidizing bacteria are affected by various factors. In the one-stage partial nitrification-anaerobic ammonium oxidation coupling process, due to the presence of dissolved oxygen in the water, the activity of anaerobic ammonium oxidizing bacteria will be inhibited, resulting in the inability to consume nitrite in a timely manner, thereby causing the accumulation of nitrate. At the same time, the organic matter in the water will promote the proliferation of heterotrophic bacteria, competing with anaerobic ammonium oxidizing bacteria and causing a sludge age conflict. In the two-stage partial nitrification-anaerobic ammonium oxidation coupling process, how to control the nitrification process to stop at the partial nitrification stage and stably supply nitrite is an important challenge faced by this process. In addition, due to the organic matter in the water also causing the proliferation of heterotrophic bacteria, there will also be a sludge age problem. In the one-stage partial denitrification-anaerobic ammonium oxidation coupling process, there are mainly three technical problems: (1) It is necessary to first completely nitrate the ammonia nitrogen in part of the sewage into nitrate, and then mix it with the raw sewage and enter the partial denitrification-anaerobic ammonium oxidation reactor for denitrification, which requires precise control of the nitrification influent ratio and increases the process complexity; (2) It is necessary to control the denitrification process to stop at the partial denitrification stage and stably supply nitrite for anaerobic ammonium oxidation denitrification; (3) The one-stage reaction will also have a sludge age problem.

[0004] Based on the above content, the present invention provides a denitrification system based on the anaerobic ammonium oxidation technology, which can effectively solve the problems of too low sludge age and dissolved oxygen inhibiting the activity of anaerobic ammonium oxidizing bacteria in the one-stage partial nitrification-anaerobic ammonium oxidation coupling process, as well as the problems of unstable nitrite supply and organic matter competing for nitrite in the two-stage partial nitrification-anaerobic ammonium oxidation coupling process, and can efficiently treat nitrogen-containing wastewater. SUMMARY OF THE INVENTION:

[0005] The object of the present invention is to provide a denitrification system based on the anaerobic ammonium oxidation technology in view of the deficiencies of the prior art.

[0006] In order to achieve the above technical object, the present invention adopts the following technical solutions:

[0007] The present invention provides a denitrification system based on the anaerobic ammonium oxidation technology, which includes an anaerobic ammonium oxidation zone, a nitrification and denitrification zone, an alternating current power supply and two groups of electrode plates; anaerobic ammonium oxidation sludge is arranged inside the anaerobic ammonium oxidation zone, and nitrification sludge is arranged inside the nitrification and denitrification zone; an amphoteric ion exchange membrane is arranged between the anaerobic ammonium oxidation zone and the nitrification and denitrification zone; the two groups of electrode plates are respectively arranged in the anaerobic ammonium oxidation zone and the nitrification and denitrification zone and are connected to the alternating current power supply to form an alternating current electric field; nitrification reaction occurs in the nitrification and denitrification zone to generate nitrite nitrogen, and ammonium ions and nitrite ions in the nitrification and denitrification zone enter the anaerobic ammonium oxidation zone through the amphoteric ion exchange membrane to carry out anaerobic ammonium oxidation reaction. The nitrate generated by anaerobic ammonium oxidation enters the nitrification and denitrification zone through the amphoteric ion exchange membrane to carry out denitrification reaction and is reduced to nitrite nitrogen and nitrogen gas, so as to realize the denitrification function through such a cycle.

[0008] Further, one group or more than one group of stirrers are arranged in the anaerobic ammonium oxidation zone, and the stirrers are evenly installed inside the anaerobic ammonium oxidation zone.

[0009] Further, an aeration device is arranged inside the nitrification and denitrification zone. The aeration device includes an aeration main pipe and aeration branch pipes. The aeration main pipe is communicated with the outside, and the aeration branch pipes are perpendicular to the aeration main pipe.

[0010] Further, a partition board is arranged between the anaerobic ammonium oxidation zone and the nitrification and denitrification zone. Through holes for installing the amphoteric ion exchange membrane are opened on the partition board, and the amphoteric ion exchange membrane is fixed in the through holes of the partition board.

[0011] Further, the two groups of electrode plates are arranged in parallel and symmetrically distributed on both sides of the amphoteric ion exchange membrane.

[0012] Further, the two groups of electrode plates are respectively fixedly installed in the anaerobic ammonium oxidation zone and the nitrification and denitrification zone through electrode support frames; the electrode support frames are fixedly installed on the partition board, and the electrode plates are fixedly connected to the electrode support frames.

[0013] Further, a steel cover plate is arranged above the anaerobic ammonium oxidation zone.

[0014] Further, the denitrification system is provided with a water outlet pipe and a water outlet area, and both the water outlet pipe and the water outlet area are arranged in the nitrification and denitrification zone; a water outlet weir is further arranged on the side of the nitrification and denitrification zone where water flows out.

[0015] Furthermore, the denitrification system is provided with a water inlet pipe, a nitrification-denitrification water inlet area, and an anammox water inlet area; a first water passing hole is arranged between the nitrification-denitrification water inlet area and the nitrification-denitrification area, and a second water passing hole is arranged between the anammox water inlet area and the anammox area; and a water distribution area is arranged between the nitrification-denitrification water inlet area and the anammox water inlet area, and the water inlet pipe is connected to the water distribution area; a first water inlet weir is arranged between the nitrification-denitrification water inlet area and the water distribution area, and a second water inlet weir is arranged between the anammox water inlet area and the water distribution area.

[0016] Advantages of the present invention:

[0017] The present invention effectively solves the problems of too low sludge age and dissolved oxygen inhibiting the activity of anammox bacteria in the one-stage short-cut nitrification-anammox coupling process, and the problems of unstable nitrite supply and organic matter competing for nitrite in the two-stage short-cut nitrification-anammox coupling process; at the same time, the present invention also overcomes the problems of unstable nitrite supply and too low sludge age in the short-cut denitrification-anammox coupling process. Compared with the traditional denitrification process, the present invention has the characteristics of energy saving, carbon saving, and sludge reduction. The present invention is reasonably designed, has a simple structure, can achieve efficient denitrification of sewage, and has strong practicability. Description of the drawings:

[0018] Figure 1 is a schematic plan structure diagram of the denitrification system according to an embodiment of the present invention;

[0019] Figures 2 to 4 is a sectional view of the denitrification system according to an embodiment of the present invention;

[0020] Figure 5 is a schematic principle diagram of the denitrification system according to an embodiment of the present invention;

[0021] The marks in the drawings are:

[0022] 1. Anammox area; 2. Nitrification-denitrification area; 3. Zwitterionic exchange membrane; 4. AC power supply; 5. Electrode plate; 6. Agitator; 7. Steel cover plate; 8. Main aeration pipe; 9. Aeration branch pipe; 10. Water distribution area; 11. Nitrification-denitrification water inlet area; 12. Anammox water inlet area; 13. First water passing hole; 14. First water inlet weir; 15. Water outlet weir; 16. Electrode support frame; 17. Water outlet pipe; 18. Water outlet area; 19. Second water inlet weir; 20. Second water passing hole; 21. Water inlet pipe. Specific embodiments:

[0023] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of the present invention.

[0024] Embodiment 1

[0025] Referring to Figures 1 to 5 , an embodiment of the present invention provides a nitrogen removal system based on the anaerobic ammonium oxidation technology, which includes an anaerobic ammonium oxidation zone 1, a nitrification and denitrification zone 2, an alternating current power supply 4, and two groups of electrode plates 5; a steel cover plate 7 is arranged above the anaerobic ammonium oxidation zone 1, and anaerobic ammonium oxidation sludge is arranged inside the anaerobic ammonium oxidation zone 1, and nitrification sludge is arranged inside the nitrification and denitrification zone 2; an amphoteric ion exchange membrane 3 is arranged between the anaerobic ammonium oxidation zone 1 and the nitrification and denitrification zone 2; the two groups of electrode plates 5 are respectively arranged in the anaerobic ammonium oxidation zone 1 and the nitrification and denitrification zone 2 and are connected to the alternating current power supply 4 to form an alternating current electric field, so as to realize the transmembrane exchange of ammonia nitrogen and nitrite in the sewage on both sides of the amphoteric ion exchange membrane 3, meet the substrate requirements of the anaerobic ammonium oxidation reaction, and realize efficient nitrogen removal.

[0026] In this embodiment, an aeration device is arranged inside the nitrification and denitrification zone 2, and the aeration device includes an aeration main pipe 8 and several groups of aeration branch pipes 9. The aeration main pipe 8 is communicated with the outside, and the aeration branch pipes 9 are perpendicular to the aeration main pipe 8.

[0027] During application, the nitrogen-containing sewage enters the nitrification and denitrification zone 2, and under microaerobic conditions, a nitrification reaction is carried out to oxidize part of the ammonia nitrogen into nitrite; then, under the action of the alternating current electric field, ammonium ions and nitrite nitrogen are transferred to the anaerobic ammonium oxidation zone 1 through the amphoteric ion exchange membrane 3, and an anaerobic ammonium oxidation reaction occurs to be converted into nitrogen gas; at the same time, part of the nitrate produced during the anaerobic ammonium oxidation process is transferred to the nitrification and denitrification zone 2 through the amphoteric ion exchange membrane 3 and is reduced to nitrite and nitrogen gas by denitrifying bacteria under microaerobic conditions, and the nitrogen removal effect is realized in such a cycle. Theoretically, the system can achieve a 100% nitrogen removal efficiency. In addition, the organic matter in the influent can also be removed through two ways of denitrification and aerobic heterotrophy, realizing the carbon and nitrogen removal treatment of sewage.

[0028] Embodiment 2

[0029] An embodiment of the present invention provides a nitrogen removal system based on the anaerobic ammonium oxidation technology, and its main structure is the same as that of Embodiment 1, except that: the internal structure of the nitrogen removal system is specifically defined in this application.

[0030] Specifically, referring toFigures 1 to 4 In this embodiment, two agitators 6 are arranged in the anaerobic ammonium oxidation zone 1. The agitators 6 are installed inside the anaerobic ammonium oxidation zone 1 to play a role in agitation. A partition plate is arranged between the anaerobic ammonium oxidation zone 1 and the nitrification and denitrification zone 2. A rectangular through-hole for installing the zwitterionic exchange membrane 3 is formed on the partition plate, and the zwitterionic exchange membrane 3 is fixed in the rectangular through-hole of the partition plate.

[0031] In this embodiment, the two electrode plates 5 are arranged in parallel and symmetrically distributed on both sides of the zwitterionic exchange membrane 3. The two electrode plates 5 are respectively fixedly installed in the anaerobic ammonium oxidation zone 1 and the nitrification and denitrification zone 2 through the electrode support frames 16. The electrode support frames 16 are fixedly installed on the partition plate, and the electrode plates 5 are fixedly connected to the electrode support frames 16.

[0032] Embodiment 3

[0033] An embodiment of the present invention provides a nitrogen removal system based on the anaerobic ammonium oxidation technology. Its main structure is the same as that of Embodiment 1, except that: in this application, the influent and effluent of the nitrogen removal system are specifically defined.

[0034] Specifically, referring to Figures 1 to 4 In this embodiment, the nitrogen removal system is provided with an outlet pipe 17 and an outlet area 18. The outlet pipe 17 and the outlet area 18 are both arranged in the nitrification and denitrification zone 2. An outlet weir 15 is further arranged on the side of the nitrification and denitrification zone 2 where the water exits. The treated water enters the outlet area 18 through the outlet weir 15 and is finally discharged through the outlet pipe 17.

[0035] In this embodiment, the nitrogen removal system is provided with an influent pipe 21, a nitrification and denitrification influent area 11, and an anaerobic ammonium oxidation influent area 12. A first water passing hole 13 is arranged between the nitrification and denitrification influent area 11 and the nitrification and denitrification zone 2, and a second water passing hole 20 is arranged between the anaerobic ammonium oxidation influent area 12 and the anaerobic ammonium oxidation zone 1. And a water distribution area 10 is arranged between the nitrification and denitrification influent area 11 and the anaerobic ammonium oxidation influent area 12. The influent pipe 21 is connected to the water distribution area 10. A first inlet weir 14 is arranged between the nitrification and denitrification influent area 11 and the water distribution area 10, and a second inlet weir 19 is arranged between the anaerobic ammonium oxidation influent area 12 and the water distribution area 10.

[0036] When initially inflowing water, the nitrogen-containing sewage to be treated enters the water distribution area 10 through the influent pipe 21, enters the nitrification and denitrification influent area 11 and the anaerobic ammonium oxidation influent area 12 respectively through the first inlet weir 14 and the second inlet weir 19, and then enters the nitrification and denitrification zone 2 and the anaerobic ammonium oxidation zone 1 respectively through the first water passing hole 13 and the second water passing hole 20. After the anaerobic ammonium oxidation zone 1 is filled with water, no more water enters, and the nitrogen is only mixed through ion diffusion and ion exchange, and the nitrogen removal reaction occurs and then is removed.

[0037] The application steps of the present invention are as follows:

[0038] (1) Anaerobic ammonium oxidation sludge and nitrification sludge are inoculated in the anaerobic ammonium oxidation zone 1 and the nitrification and denitrification zone 2 respectively to establish a nitrogen removal system;

[0039] (2) For municipal sewage or industrial nitrogen-containing sewage without heavy metal ions, it is first pretreated and then enters the nitrogen removal system of the present invention;

[0040] (3) Ammonia nitrogen in the sewage undergoes short-term nitrification to generate nitrite nitrogen in the nitrification and denitrification zone 2. Subsequently, under the action of an alternating current electric field, ammonium ions and nitrite ions move to the anaerobic ammonium oxidation zone through the zwitterionic exchange membrane 3 to achieve nitrogen removal;

[0041] (4) The nitrate generated by anaerobic ammonium oxidation passes through the zwitterionic exchange membrane 3 again under the action of the alternating current electric field and returns to the nitrification and denitrification zone 2, where it is reduced to nitrite nitrogen or nitrogen gas; at the same time, the organic matter in the influent is also degraded in this area;

[0042] (5) The sewage undergoes carbon and nitrogen removal treatment and then discharges.

[0043] The above is only the preferred implementation mode of the present invention. The protection scope of the present invention is not limited to the above embodiments. All technical solutions falling within the concept of the present invention belong to the protection scope of the present invention. It should be noted that for those of ordinary skill in the art, several improvements and refinements made without departing from the principle of the present invention should be regarded as within the protection scope of the present invention.

Claims

1. A nitrogen removal system based on the anaerobic ammonium oxidation technology, characterized in that, it includes an anaerobic ammonium oxidation zone (1), a nitrification and denitrification zone (2), an alternating current power supply (4) and two groups of electrode plates (5); anaerobic ammonium oxidation sludge is arranged inside the anaerobic ammonium oxidation zone (1), and nitrifying sludge is arranged inside the nitrification and denitrification zone (2); an amphoteric ion exchange membrane (3) is arranged between the anaerobic ammonium oxidation zone (1) and the nitrification and denitrification zone (2); the two groups of electrode plates (5) are respectively arranged inside the anaerobic ammonium oxidation zone (1) and the nitrification and denitrification zone (2), and are connected to the alternating current power supply (4) to form an alternating current electric field; nitrification reaction occurs in the nitrification and denitrification zone (2) to generate nitrite nitrogen. Ammonium ions and nitrite ions in the nitrification and denitrification zone (2) enter the anaerobic ammonium oxidation zone (1) through the amphoteric ion exchange membrane (3) to carry out anaerobic ammonium oxidation reaction. The nitrate ions generated by anaerobic ammonium oxidation enter the nitrification and denitrification zone through the amphoteric ion exchange membrane (3) for denitrification reaction, and are reduced to nitrite nitrogen and nitrogen gas, and the nitrogen removal function is realized through such circulation.

2. The nitrogen removal system based on the anaerobic ammonium oxidation technology according to claim 1, characterized in that, one group or more than one group of stirrers (6) are arranged inside the anaerobic ammonium oxidation zone (1), and the stirrers (6) are evenly installed inside the anaerobic ammonium oxidation zone (1).

3. The nitrogen removal system based on the anaerobic ammonium oxidation technology according to claim 1, characterized in that, an aeration device is arranged inside the nitrification and denitrification zone (2), the aeration device includes an aeration main pipe (8) and aeration branch pipes (9), the aeration main pipe (8) is communicated with the outside, and the aeration branch pipes (9) are perpendicular to the aeration main pipe (8).

4. The nitrogen removal system based on the anaerobic ammonium oxidation technology according to claim 1, characterized in that, a partition board is arranged between the anaerobic ammonium oxidation zone (1) and the nitrification and denitrification zone (2), through holes for installing the amphoteric ion exchange membrane (3) are formed on the partition board, and the amphoteric ion exchange membrane (3) is fixed in the through holes of the partition board.

5. The nitrogen removal system based on the anaerobic ammonium oxidation technology according to claim 4, characterized in that, the two groups of electrode plates (5) are arranged in parallel and symmetrically distributed on both sides of the amphoteric ion exchange membrane (3).

6. The nitrogen removal system based on the anaerobic ammonium oxidation technology according to claim 5, characterized in that, the two groups of electrode plates (5) are respectively fixedly installed inside the anaerobic ammonium oxidation zone (1) and the nitrification and denitrification zone (2) through electrode support frames (16); the electrode support frames (16) are fixedly installed on the partition board, and the electrode plates (5) are fixedly connected to the electrode support frames (16).

7. The nitrogen removal system based on the anaerobic ammonium oxidation technology according to claim 1, characterized in that, a steel cover plate (7) is arranged above the anaerobic ammonium oxidation zone (1).

8. The nitrogen removal system based on the anaerobic ammonium oxidation technology according to claim 1, characterized in that, the nitrogen removal system is provided with a water outlet pipe (17) and a water outlet area (18), and both the water outlet pipe (17) and the water outlet area (18) are arranged in the nitrification and denitrification zone (2); On one side of the effluent in the nitrification-denitrification zone (2), an effluent weir (15) is also provided.

9. The nitrogen removal system based on the anaerobic ammonium oxidation technology according to claim 1, characterized in that the nitrogen removal system is provided with a water inlet pipe (21), a nitrification-denitrification water inlet zone (11) and an anaerobic ammonium oxidation water inlet zone (12); a first water passing hole (13) is arranged between the nitrification-denitrification water inlet zone (11) and the nitrification-denitrification zone (2), and a second water passing hole (20) is arranged between the anaerobic ammonium oxidation water inlet zone (12) and the anaerobic ammonium oxidation zone (1); and a water distribution zone (10) is arranged between the nitrification-denitrification water inlet zone (11) and the anaerobic ammonium oxidation water inlet zone (12), and the water inlet pipe (21) is connected to the water distribution zone (10); a first water inlet weir (14) is arranged between the nitrification-denitrification water inlet zone (11) and the water distribution zone (10), and a second water inlet weir (19) is arranged between the anaerobic ammonium oxidation water inlet zone (12) and the water distribution zone (10).

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