A treatment system and treatment method for low-carbon high-ammonia-nitrogen wastewater

Abstract

The application provides a treatment system and method for low-carbon high-ammonia-nitrogen wastewater, which comprises a hydrolysis acidification tank, a nitritation / anaerobic ammonia oxidation / denitrification chamber and an aerobic MBR tank connected in sequence; the hydrolysis acidification tank is provided with a wastewater inlet, and is connected with the bottom of the nitritation reaction zone; the aerobic MBR tank is provided with a water outlet connected with the outside; the nitritation / anaerobic ammonia oxidation / denitrification chamber comprises two parts separated by a partition, the inside is the nitritation reaction zone, and the outside is the anaerobic ammonia oxidation and denitrification reaction zone, and the water flow can pass through the top of the partition. The application controls the aeration amount of the MBR aeration tank and the reflux ratio, controls the dissolved oxygen of the nitritation / anaerobic ammonia oxidation / denitrification chamber in the required range, stably creates the environment required for nitritation and anaerobic ammonia oxidation, simultaneously performs the nitritation, anaerobic ammonia oxidation and denitrification reaction in the integrated anaerobic ammonia oxidation tank, removes total nitrogen and part of organic matters, can not only efficiently remove total nitrogen and organic matters, but also save the aeration amount and energy.

Description

Technical Field

[0001] The present invention relates to the technical field of low-carbon high-ammonia nitrogen wastewater treatment, and in particular to a low-carbon high-ammonia nitrogen wastewater treatment system and treatment method. Background Art

[0002] With the improvement of living standards and the rapid development of the petrochemical, pharmaceutical, and food industries, nitrogen concentrations in wastewater have gradually increased. Traditional biological denitrification processes have high requirements for organic matter and are unable to meet the denitrification requirements of wastewater with a low carbon-to-nitrogen ratio. Anaerobic ammonium-oxidizing bacteria, on the other hand, use carbon dioxide or carbonates as a carbon source, ammonia nitrogen as an electron donor, and nitrite nitrogen as an electron acceptor to react and produce nitrogen gas and a small amount of nitrate nitrogen. Compared with traditional denitrification processes, anaerobic ammonium-oxidizing processes do not require an external carbon source, which can reduce operating costs. Furthermore, anaerobic ammonium-oxidizing bacteria grow slowly, resulting in low sludge production and reduced sludge disposal costs.

[0003] Although the anaerobic ammonium oxidation process has many advantages over the traditional denitrification process, the anaerobic ammonium oxidation process has problems with the retention of anaerobic ammonium oxidizing bacteria and the requirement for short-range nitrification stability, which limits the large-scale promotion and application of the anaerobic ammonium oxidation process in engineering.

[0004] The primary biological denitrification pathway for wastewater is traditional nitrification and denitrification, but its engineering application still results in high energy consumption and difficulty achieving low carbonization. Anaerobic ammonium oxidation (ANAMMOX) uses ammonia as an electron donor and nitrite as an electron acceptor under anaerobic conditions, achieving simultaneous removal of ammonia and nitrite while generating nitrogen gas. Compared to traditional nitrification and denitrification processes, new ANAMMOX-based processes can effectively reduce aeration costs, sludge production, and organic carbon source requirements, making them a key development direction for future biological denitrification of wastewater.

[0005] Compared with traditional denitrification processes, the anaerobic ammonium oxidation process does not require an external carbon source, which can save operating costs. The anaerobic ammonium oxidation process can also save aeration costs. In addition, the anaerobic ammonium oxidizing bacteria grow slowly and the sludge production is low, which saves sludge disposal costs.

[0006] While possessing these advantages, the ANAMMOX process also faces challenges with ANAMMOX bacteria retention and the stability of short-cut nitrification. Furthermore, in actual production using the ANAMMOX process, short-cut nitrification and ANAMMOX reactions are typically set up in two reactors, increasing the number of processing steps and occupying a larger area. Summary of the Invention

[0007] The present invention provides a treatment system and method for low-carbon, high-ammonia nitrogen wastewater. The system treats high-ammonia nitrogen, low-carbon-nitrogen ratio wastewater through a combination of a hydrolysis and acidification tank, a nitritation / anaerobic ammonium oxidation / denitrification chamber, and an aerobic MBR tank. The combined process provided by the present invention can not only efficiently remove total nitrogen and organic matter, but also save aeration volume and energy.

[0008] The specific technical solutions are as follows:

[0009] The present invention first provides a treatment system for low-carbon high-ammonia nitrogen wastewater, the treatment system comprising a hydrolysis acidification tank, a nitritation / anaerobic ammonium oxidation / denitrification chamber and an aerobic MBR tank connected in sequence;

[0010] The hydrolysis and acidification tank is provided with a wastewater inlet, the hydrolysis and acidification tank is connected to the bottom of the nitrification reaction zone, and the aerobic MBR tank is provided with a water outlet connected to the outside world;

[0011] The nitritation / anaerobic ammonium oxidation / denitrification chamber includes an inner and outer part separated by a partition, the inner part is a nitritation reaction zone, and the outer part is an anaerobic ammonium oxidation and denitrification reaction zone, and water can flow through the top of the partition;

[0012] A gas collecting hood for collecting the gas generated by the nitritation reaction is provided on the top of the nitritation reaction zone, and an exhaust pipe is provided in communication with the gas collecting hood to discharge the gas generated by the reaction in the nitritation / anaerobic ammonium oxidation / denitrification chamber.

[0013] Furthermore, the partition is cylindrical or cylindrical with a polygonal cross section, and is composed of multiple multi-layer wire mesh corrugated sheets.

[0014] Furthermore, bottle brush-shaped three-dimensional elastic fillers are suspended on the pores on both sides of the surface of the wire mesh corrugated sheet, ammonia oxidizing bacteria are enriched on the three-dimensional elastic fillers suspended on one side of the nitrite reaction zone, and anaerobic ammonia oxidizing bacteria and denitrifying bacteria are enriched on the three-dimensional elastic fillers suspended on one side of the anaerobic ammonia oxidation and denitrification reaction zone.

[0015] Existing anaerobic ammonium oxidation (ANAMMOX) systems are prone to sludge bulking, which can lead to sludge loss and denitrification system collapse. The combination of wire mesh corrugated sheets and filler in this invention effectively enriches ANAMMOX bacteria, effectively preventing sludge loss in the MBR effluent. The integrated nitritation / ANAMMOX / denitrification system exhibits a step-by-step DO variation trend, increasing the diversity and activity of microorganisms within the system. The integrated reactor simplifies the process flow and saves floor space.

[0016] Furthermore, a water pipe is provided between the nitritation / anaerobic ammonium oxidation / denitrification chamber and the aerobic MBR tank, and the connection point between the water pipe and the anaerobic ammonium oxidation and denitrification reaction zone is set below the top of the partition.

[0017] Furthermore, a guide plate is provided on the gas collecting hood, and the guide plate is used to guide the water flowing out from the top of the partition in the nitrite reaction zone to the bottom of the anaerobic ammonium oxidation and denitrification reaction zone.

[0018] Furthermore, a heater and a dissolved oxygen meter are provided in the nitrite reaction zone; and a pH monitor and a dissolved oxygen meter are provided in the anaerobic ammonia oxidation and denitrification reaction zone.

[0019] The present invention further provides a wastewater treatment method using the low-carbon high-ammonia nitrogen wastewater treatment system, comprising the following steps:

[0020] (1) Pumping the initial wastewater into a hydrolysis and acidification tank for hydrolysis and acidification treatment to obtain wastewater I;

[0021] (2) Wastewater I enters the nitrification reaction zone from the bottom of the nitrification / anaerobic ammonium oxidation / denitrification chamber, and after treatment, wastewater II is obtained. Wastewater II enters the anaerobic ammonium oxidation and denitrification reaction zone, and after treatment, wastewater II I is obtained.

[0022] (3) Wastewater II flows into the aerobic MBR tank by gravity and is treated to obtain wastewater IV;

[0023] (4) Wastewater IV is mixed with wastewater I and then enters the nitrification / anaerobic ammonium oxidation / denitrification chamber for treatment to obtain wastewater V;

[0024] (5) Steps (3) to (4) are repeated until the wastewater index meets the design requirements, and the treated water is discharged from the outlet to the clean water tank.

[0025] Furthermore, in step (1), the initial influent pH value is 7.5-8, and the C / N ratio is 1-3.

[0026] Furthermore, in step (2), the hydraulic retention time in the nitritation / anaerobic ammonium oxidation / denitrification chamber is 24 h to 36 h.

[0027] Furthermore, in step (2), the temperature of the nitritation reaction zone is 32-34° C.; the dissolved oxygen in the nitritation reaction zone is 0.5-1.0 mg / L, and the dissolved oxygen in the anaerobic ammonium oxidation and denitrification reaction zone is 0-0.3 mg / L.

[0028] Furthermore, in step (3), the dissolved oxygen in the aerobic MBR tank is 1-2 mg / L; and the reflux ratio of the wastewater in the aerobic MBR tank is 50-150%.

[0029] In the present invention, the nitritation reaction zone, the anaerobic ammonium oxidation and denitrification reaction zone are designed in an integrated manner. The reactions carried out in the two treatment areas are aerobic and anaerobic reactions, respectively. The reactions carried out by the anaerobic ammonium oxidizing bacteria and denitrifying bacteria in the anaerobic ammonium oxidation and denitrification reaction zones are affected by the dissolved oxygen in the water. The dissolved oxygen source of the wastewater in the nitritation / anaerobic ammonium oxidation / denitrification chamber is mainly the return wastewater from the aerobic MBR pool, and the ammonia oxidizing bacteria in the nitritation reaction zone consumes the dissolved oxygen in the nitritation / anaerobic ammonium oxidation / denitrification chamber. Therefore, the dissolved oxygen level of the wastewater in the anaerobic ammonium oxidation and denitrification reaction zone is determined by the oxygen consumption level of the return wastewater from the aerobic MBR pool and the reactions in the nitritation reaction zone. It can be seen that the hydraulic retention time in the nitritation / anaerobic ammonium oxidation / denitrification chamber, the dissolved oxygen level in the aerobic MBR pool and the return ratio of the aerobic MBR pool wastewater mainly determine the dissolved oxygen level of the wastewater in the anaerobic ammonium oxidation and denitrification reaction zone.

[0030] The applicant of the present invention has obtained the conditions most suitable for the device used in the present invention through continuous exploration of the hydraulic retention time of the nitritation / anaerobic ammonium oxidation / denitrification chamber, the dissolved oxygen level in the aerobic MBR tank, and the reflux ratio. The hydraulic retention time is designed to be 24h~48h, so that the ammonia oxidizing bacteria in the nitrite reaction zone can fully consume the dissolved oxygen in the wastewater to prevent the reactions in the anaerobic ammonium oxidation and denitrification reaction zones from being inhibited; the dissolved oxygen in the aerobic MBR tank is set to 1~2mg / L, so that after the dissolved oxygen in the wastewater in the aerobic MBR tank is consumed by aerobic respiration in the aerobic MBR tank, the dissolved oxygen in the wastewater returned to the nitrite reaction zone can still support the reaction of ammonia oxidizing bacteria, and the dissolved oxygen in the nitrite / anaerobic ammonium oxidation / denitrification chamber after consumption by ammonia oxidizing bacteria is at a level suitable for the reaction of anaerobic ammonium oxidizing bacteria and denitrifying bacteria; the reflow ratio of the wastewater in the aerobic MBR tank is set to 50~150%, which can not only ensure the denitrification efficiency of the nitrite / anaerobic ammonium oxidation / denitrification chamber, but also avoid excessive dissolved oxygen in the anaerobic ammonium oxidation and denitrification reaction zones due to a relatively high reflow ratio.

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] The present invention treats high-ammonia-nitrogen and low-carbon-nitrogen ratio wastewater through the combination of a hydrolysis acidification tank, a nitritation / anaerobic ammonium oxidation / denitrification chamber, and an aerobic MBR tank. By controlling the aeration volume and reflux ratio of the aerobic MBR tank, the dissolved oxygen in the internal area of ​​the nitritation / anaerobic ammonium oxidation / denitrification chamber is controlled within a required range, stably creating the environment required for nitritation and anaerobic ammonium oxidation. Nitritation, anaerobic ammonium oxidation, and denitrification reactions are simultaneously carried out in the nitritation / anaerobic ammonium oxidation / denitrification chamber to remove total nitrogen and some organic matter. The combined process provided by the present invention can not only efficiently remove total nitrogen and organic matter, but also save aeration volume and energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 Schematic diagram of the connection structure of the hydrolysis acidification tank, nitritation / anaerobic ammonium oxidation / denitrification chamber and aerobic MBR tank in Example 1.

[0034] Figure 2 This is a schematic diagram of a treatment system for low-carbon, high-ammonia nitrogen wastewater in Example 2.

[0035] Figure 3 This is a top view of a half-section of the nitritation / anaerobic ammonium oxidation / denitrification chamber in Example 2.

[0036] In the figure, 1 is a hydrolysis acidification tank, 2 is a nitrification / anaerobic ammonium oxidation / denitrification chamber, 3 is an aerobic MBR tank, 4 is an MBR membrane assembly, 5 is a water inlet pipe, 6 is a water inlet pump, 7 is an elastic filler, 8 is a connecting pipe between a hydrolysis acidification tank and a nitrification / anaerobic ammonium oxidation / denitrification chamber, 9 is a pH meter, 10 is a dissolved oxygen meter, 11 is a partition, 12 is a three-dimensional elastic filler, 13 is a heater, 14 is a reflux pipe, 15 is a reflux pump, 16 is a reflux pump, 17 is a reflux pump, 18 is a reflux pump, 19 is a reflux pump, 20 is a reflux pump, 21 is a reflux pump, 22 is a reflux pump, 23 is a reflux pump, 24 is a reflux pump, 25 is a reflux pump, 26 is a reflux pump, 27 is a reflux pump, 28 is a reflux pump, 29 is a reflux pump, 30 is a reflux pump, 31 is a reflux pump, 32 is a reflux pump, 33 is a reflux pump, 34 is a reflux pump, 35 is a reflux pump, 36 is a reflux pump, 37 is a reflux pump, 38 is a reflux pump, 39 is a reflux pump, 40 is a reflux pump, 41 is a reflux pump, 42 is a reflux pipe, 43 is a reflux pump, 44 is a reflux pipe, 45 is a reflux pump, 46 is a reflux pump, 47 is a reflux pipe, 48 is a reflux pump, 4 6 is an aeration pump, 17 is an aeration pipe, 18 is a gas flow meter, 19 is a water outlet pump, 20 is a water outlet, 21 is a connecting pipe between nitritation / anaerobic ammonium oxidation / denitrification chamber and aerobic MBR pool, 22 is an exhaust pipe, 23 is a clear water pool, 24 is a gas collecting hood, 25 is a guide plate, 26 is a wire mesh corrugated sheet, 27 is a nitritation reaction zone, 28 is an anaerobic ammonium oxidation and denitrification reaction zone, 29 is a steel frame, and 30 is an installation slot. DETAILED DESCRIPTION

[0037] In order to make those skilled in the art better understand the present invention, the technical solution of the present invention is clearly and completely described below in conjunction with specific embodiments. It should be noted that the following detailed description is exemplary and is only a part of the embodiments of the present invention, rather than all embodiments.

[0038] Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative work should fall within the scope of protection of the present invention.

[0039] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

[0040] Example 1

[0041] like Figure 1 As shown, a low-carbon high-ammonia nitrogen wastewater treatment system includes a hydrolysis acidification tank 1, a nitritation / anaerobic ammonium oxidation / denitrification chamber 2 and an aerobic MBR tank 3 connected in sequence.

[0042] Hydrolysis and acidification tank 1 is equipped with an inlet pipe 5. A water pump 6 injects wastewater into the tank through the bottom of the side wall. Inside the tank, elastic packing 7 is installed. This packing is a three-dimensional elastic packing composed of polyolefin or polyamide threads interlaced and fixed to a corrosion-resistant, high-strength central rope. The threads are arranged in a three-dimensional, uniform, radial pattern. The elastic packing 7 is suspended in the tank 1. Facultative anaerobic microorganisms accumulate on the elastic packing 7, with a packing ratio of 70%. The facultative anaerobic microorganisms in the tank remove some organic matter from the wastewater and convert large organic molecules into small organic molecules. The treated wastewater then enters the nitrite / anaerobic ammonium oxidation / denitrification chamber 2 through a connecting pipe 8.

[0043] In this embodiment, the nitritation / anaerobic ammonium oxidation / denitrification chamber 2 is divided into two parts, the inner part and the outer part, by a partition 11. The inner part is a nitritation reaction zone 27, and the outer part is an anaerobic ammonium oxidation and denitrification reaction zone 28. The wastewater treated in the hydrolysis acidification tank 1 enters the nitritation / anaerobic ammonium oxidation / denitrification chamber 2 from the bottom of the nitritation reaction zone 27 through the connecting pipe 8. The wastewater flowing out of the nitritation reaction zone 27 can enter the anaerobic ammonium oxidation and denitrification reaction zone 28 through the top of the partition 11.

[0044] In this embodiment, ammonia oxidizing bacteria are enriched in the nitrification reaction zone 27. Part of the ammonia nitrogen in the effluent of the hydrolysis acidification tank 1 is oxidized to nitrite nitrogen by the ammonia oxidizing bacteria. As the water inflow increases, the wastewater after the reaction in the nitrification reaction zone 27 flows through the top of the partition 11 into the anaerobic ammonium oxidation and denitrification reaction zone 28. The anaerobic ammonium oxidation and denitrification reaction zone 28 is enriched with anaerobic ammonium oxidizing bacteria and denitrifying bacteria. The anaerobic ammonium oxidizing bacteria utilize ammonia nitrogen and nitrite nitrogen to carry out anaerobic ammonium oxidation reaction to generate nitrogen gas, and the denitrifying bacteria utilize nitrate nitrogen to carry out denitrification reaction to generate nitrogen gas. A gas collecting hood 24 is provided on the top of the nitritation / anaerobic ammonium oxidation / denitrification chamber 2, which can discharge the gases generated by each reaction through the exhaust pipe 22. At the same time, the oxygen released from the effluent of the nitritation reaction zone 27 is also discharged through the exhaust pipe 22 to prevent oxygen from entering the water being treated in the anaerobic ammonium oxidation and denitrification reaction zone 28, thereby ensuring the smooth progress of the anaerobic reaction. The gas discharged through the exhaust pipe 22 is discharged into the clear water tank 23 to prevent pollution to the environment.

[0045] A heater 13 is installed on the baffle 11 in the nitritation reaction zone 27 to control the temperature of the wastewater in the entire nitritation / anaerobic ammonium oxidation / denitrification chamber 2 at 32-34°C. A dissolved oxygen meter 10 is installed in the nitritation reaction zone 27 to ensure that the dissolved oxygen in the nitritation reaction zone 27 is controlled at 0.5-1.0 mg / L. The anaerobic ammonium oxidation and denitrification reaction zone 28 is equipped with a dissolved oxygen meter 10 and a pH meter 9 to ensure that the dissolved oxygen in the anaerobic ammonium oxidation and denitrification reaction zone 28 is 0-0.3 mg / L.

[0046] The wastewater treated by the nitritation / anaerobic ammonium oxidation / denitrification chamber 2 enters the aerobic MBR pool 3 through the connecting pipe 21. To ensure that the wastewater can flow out smoothly, the connection between the nitritation / anaerobic ammonium oxidation / denitrification chamber 2 and the connecting pipe 21 is lower than the top of the partition 11. In order to prevent part of the wastewater after the reaction in the nitritation reaction zone 27 from flowing directly out of the connecting pipe 21 after passing through the top of the partition 11, a guide plate 25 is fixedly connected to the gas collecting hood 24 to block the wastewater passing through the top of the partition 11 and divert the wastewater to the bottom of the anaerobic ammonium oxidation and denitrification reaction zone 28.

[0047] In the aerobic MBR tank 3, the remaining unremoved organic matter and ammonia nitrogen in the wastewater are converted into inorganic matter and ammonia nitrogen into nitrate nitrogen under the aerobic respiration of aerobic microorganisms such as rotifers, bellworms, and nitrifying bacteria in the aerobic MBR tank 3. The treated wastewater is returned to the nitrite / anaerobic ammonium oxidation / denitrification chamber 2 by the reflux pump 15 through the reflux pipe 14 for ammonia nitrogen removal treatment.

[0048] In order to ensure that aerobic respiration of organisms in the aerobic MBR tank 3 proceeds smoothly, an aeration pipe 17 is provided at the bottom of the aerobic MBR tank 3. The aeration pipe 17 is connected to a gas flow meter 18 and an aeration pump 16 to control the dissolved oxygen in the aerobic MBR tank 3 at 1-2 mg / L. Part of the dissolved oxygen is consumed by the aerobic respiration of the organisms, and part of the dissolved oxygen enters the nitrite reaction zone 27 with the reflux of wastewater to participate in the reaction.

[0049] In the aerobic MBR tank 3, an MBR membrane assembly 4 is installed at the water outlet 20. The MBR membrane assembly 4 removes suspended solids from the water and completely traps microorganisms within the aerobic MBR tank 3. The wastewater refluxes through the nitritation / anaerobic ammonium oxidation / denitrification chamber 2 and the aerobic MBR tank 3 until the organic matter and ammonia nitrogen content in the wastewater reaches the design requirements. The wastewater is then filtered through the aerobic tank MBR membrane assembly 4 and discharged from the water outlet 20, completing the wastewater treatment.

[0050] Example 2

[0051] like Figure 1 As shown, a low-carbon high-ammonia nitrogen wastewater treatment system includes a hydrolysis acidification tank 1, a nitritation / anaerobic ammonium oxidation / denitrification chamber 2 and an aerobic MBR tank 3 connected in sequence.

[0052] Hydrolysis and acidification tank 1 is equipped with an inlet pipe 5. A water pump 6 injects wastewater into the tank through the bottom of the side wall. Inside the tank, elastic packing 7 is installed. This packing is a three-dimensional elastic packing composed of polyolefin or polyamide threads interlaced and fixed to a corrosion-resistant, high-strength central rope. The threads are arranged in a three-dimensional, uniform, radial pattern. The elastic packing 7 is suspended in the tank 1. Facultative anaerobic microorganisms accumulate on the elastic packing 7, with a packing ratio of 70%. The facultative anaerobic microorganisms in the tank remove some organic matter from the wastewater and convert large organic molecules into small organic molecules. The treated wastewater then enters the nitrite / anaerobic ammonium oxidation / denitrification chamber 2 through a connecting pipe 8.

[0053] The nitrification / anaerobic ammonium oxidation / denitrification chamber 2 is divided into two parts, the inner part is the nitrification reaction zone 27, and the outer part is the anaerobic ammonium oxidation and denitrification reaction zone 28. The wastewater treated in the hydrolysis acidification tank 1 enters the nitrification / anaerobic ammonium oxidation / denitrification chamber 2 from the bottom of the nitrification reaction zone 27 through the connecting pipe 8.

[0054] In this embodiment, if Figure 3 As shown, four partitions 11 are provided. Each partition 11 includes a steel frame 29 and a multi-layer wire mesh corrugated sheet 26 installed inside the steel frame 29. The multi-layer wire mesh corrugated sheet 26 is fixed by steel wire bundling and installed in the steel frame 29.

[0055] In this embodiment, the steel frame 29 is detachably mounted in the mounting groove 30 at the bottom of the nitritation / anaerobic ammonium oxidation / denitrification chamber 2 to prevent the wastewater in the nitritation reaction zone 27 from entering the anaerobic ammonium oxidation and denitrification reaction zone 28 from the bottom of the steel frame 29 without nitritation treatment.

[0056] In this embodiment, the steel mesh on the top of the steel frame 29 is set to be detachable, and it can be fully opened to put the wire mesh corrugated sheet 26 in. When the steel mesh on the top of the steel frame 29 is reinstalled, the wire mesh corrugated sheet 26 tightly fills the interior of the steel frame 29. When the wire mesh corrugated sheet 26 needs to be replaced, the steel mesh on the top of the steel frame 29 is removed and the wire mesh corrugated sheet 26 can be replaced.

[0057] In this embodiment, the wire mesh corrugated sheet 26 is made of metal mesh and consists of vertically arranged corrugated wire mesh strips. The corrugations of two adjacent strips are in opposite directions, and water can pass through the wire mesh corrugated sheet 26.

[0058] The three-dimensional elastic filler 12 is evenly tied to the steel mesh on the inner and outer surfaces of the steel frame 29. Ammonia oxidizing bacteria are enriched on the three-dimensional elastic filler 12 in the nitrite reaction zone 27, and anaerobic ammonia oxidizing bacteria and denitrifying bacteria are enriched on the three-dimensional elastic filler 12 in the anaerobic ammonia oxidation and denitrification reaction zone 28. When the three-dimensional elastic filler 12 needs to be replaced, the three-dimensional elastic filler 12 can be replaced by disassembling the steel frame 29.

[0059] In this embodiment, wastewater treated in the hydrolysis and acidification tank 1 enters the nitrification reaction zone 27 from the bottom of the nitrification reaction zone 27 via the connecting pipe 21. A portion of the ammonia nitrogen in the effluent from the hydrolysis and acidification tank 1 is oxidized to nitrite nitrogen by ammonia-oxidizing bacteria enriched on the three-dimensional elastic filler 12. The wastewater passing through the nitrification reaction zone 27 passes through the partition 11 and enters the anaerobic ammonium oxidation and denitrification reaction zone 28. It is then treated by the anaerobic ammonium oxidizing bacteria and denitrifying bacteria enriched on the three-dimensional elastic filler 12 on this side. The anaerobic ammonium oxidizing bacteria utilize ammonia nitrogen and nitrite nitrogen to undergo anaerobic ammonium oxidation, generating nitrogen gas, while the denitrifying bacteria utilize nitrate nitrogen to undergo denitrification, generating nitrogen gas. A gas collecting hood 24 is provided on the top of the nitritation / anaerobic ammonium oxidation / denitrification chamber 2, which can discharge the gases generated by each reaction through the exhaust pipe 22. At the same time, the oxygen released from the effluent of the nitritation reaction zone 27 is also discharged through the exhaust pipe 22 to prevent oxygen from entering the water being treated in the anaerobic ammonium oxidation and denitrification reaction zone 28, thereby ensuring the smooth progress of the anaerobic reaction. The gas discharged through the exhaust pipe 22 is discharged into the clear water tank 23 to prevent pollution to the environment.

[0060] When the wastewater intake is large, a portion of the wastewater passing through the nitritation reaction zone 27 will flow into the anaerobic ammonium oxidation and denitrification reaction zone 28 through the top of the partition 11. To ensure that the wastewater can flow out smoothly, the connection between the nitritation / anaerobic ammonium oxidation / denitrification chamber 2 and the connecting pipe 21 is lower than the top of the partition 11. In order to prevent the wastewater from entering the aerobic MBR pool 3 through the connecting pipe 21 without undergoing anaerobic ammonium oxidation and denitrification treatment, after the wastewater flows through the top of the partition 11, the wastewater will be restricted by the guide plate 25 provided on the gas collecting hood 24 and flow toward the bottom of the anaerobic ammonium oxidation and denitrification reaction zone 28. The wastewater entering the anaerobic ammonium oxidation and denitrification reaction zone 28 from the top of the partition 11 is mixed with the wastewater that passes through the partition 11 and is reacted and treated by the anaerobic ammonium oxidation bacteria and denitrifying bacteria enriched on the three-dimensional elastic filler 12 on this side.

[0061] A heater 13 is installed on the baffle 11 in the nitritation reaction zone 27 to control the temperature of the wastewater in the entire nitritation / anaerobic ammonium oxidation / denitrification chamber 2 at 32-34°C. A dissolved oxygen meter 10 is installed at the bottom of the nitritation reaction zone 27 to ensure that the dissolved oxygen in the nitritation reaction zone 27 is controlled at 0.5-1.0 mg / L. The anaerobic ammonium oxidation and denitrification reaction zone 28 is equipped with a dissolved oxygen meter 10 and a pH meter 9 to ensure that the dissolved oxygen in the anaerobic ammonium oxidation and denitrification reaction zone 28 is 0-0.3 mg / L.

[0062] The wastewater treated in the nitrite / anaerobic ammonium oxidation / denitrification chamber 2 enters the aerobic MBR tank 3 through the connecting pipe 21. In the aerobic MBR tank 3, the remaining organic matter and ammonia nitrogen in the wastewater are converted into inorganic matter and ammonia nitrogen into nitrate nitrogen under the aerobic respiration of aerobic microorganisms such as rotifers, bellworms, and nitrifying bacteria in the aerobic MBR tank 3. The treated wastewater is returned to the nitrite / anaerobic ammonium oxidation / denitrification chamber 2 by the reflux pump 15 through the reflux pipe 14 for ammonia nitrogen removal treatment.

[0063] To ensure that aerobic respiration of organisms in the aerobic MBR tank 3 proceeds smoothly, an aeration pipe 17 is provided at the bottom of the aerobic MBR tank 3. The aeration pipe 17 is connected to a gas flow meter 18 and an aeration pump 16 to control the dissolved oxygen in the aerobic MBR tank 3 at 1-2 mg / L. Part of the dissolved oxygen is consumed by the aerobic respiration of the organisms, and part enters the nitrite reaction zone 27 with the reflux of wastewater to participate in the reaction.

[0064] In the aerobic MBR tank 3, an MBR membrane assembly 4 is installed at the outlet 20. The MBR membrane assembly 4 can remove suspended matter from the water and completely intercept microorganisms within the aerobic MBR tank 3. After the wastewater refluxes between the nitritation / anaerobic ammonium oxidation / denitrification chamber 2 and the aerobic MBR tank 3 until the organic matter and ammonia nitrogen content in the wastewater reaches the design requirements, the wastewater is filtered through the aerobic tank MBR membrane assembly 4 and discharged from the outlet 20, completing the wastewater treatment.

[0065] Example 3

[0066] The processing method used in this embodiment is:

[0067] (1) Pumping the initial wastewater into the hydrolysis and acidification tank 1 for hydrolysis and acidification treatment to obtain treated wastewater I;

[0068] (2) Wastewater I enters the nitrification reaction zone 27 from the bottom of the nitrification / anaerobic ammonium oxidation / denitrification chamber 2, and is treated to obtain wastewater II. Wastewater II enters the anaerobic ammonium oxidation and denitrification reaction zone 28, and is treated to obtain wastewater III.

[0069] (3) Wastewater III is pumped into aerobic MBR tank 3 and treated to obtain return wastewater IV;

[0070] (4) Wastewater IV is mixed with wastewater I and then enters nitritation / anaerobic ammonium oxidation / denitrification chamber 2 for treatment to obtain wastewater V;

[0071] (5) The wastewater V enters the aerobic MBR tank 3 and circulates steps (3) to (4) until the wastewater index meets the design requirements. The water is filtered through the aerobic tank MBR membrane module 4 and flows into the clear water tank 23.

[0072] This example uses the low-carbon, high-ammonia nitrogen wastewater treatment system of Example 1 to treat high-ammonia nitrogen, low carbon-nitrogen ratio wastewater with an average COD concentration of about 1200 mg / L, an average ammonia nitrogen concentration of about 800 mg / L, and an average total nitrogen concentration of 860 mg / L. The treated water was tested, and the results were:

[0073] In the water discharged from the system, the COD concentration is 120-150 mg / L, the ammonia nitrogen concentration is 50-60 mg / L, the total nitrogen concentration is 100-120 mg / L, and the dissolved oxygen concentration in the anaerobic ammonium oxidation and denitrification reaction zone 28 is 0.3 mg / L.

[0074] Example 4

[0075] The processing method used in this embodiment is:

[0076] (1) Pumping the initial wastewater into the hydrolysis and acidification tank 1 for hydrolysis and acidification treatment to obtain treated wastewater I;

[0077] (2) Wastewater I enters the nitrification reaction zone 27 from the bottom of the nitrification / anaerobic ammonium oxidation / denitrification chamber 2, and is treated to obtain wastewater II. Wastewater II enters the anaerobic ammonium oxidation and denitrification reaction zone 28, and is treated to obtain wastewater III.

[0078] (3) Wastewater III is pumped into aerobic MBR tank 3 and treated to obtain return wastewater IV;

[0079] (4) Wastewater IV is mixed with wastewater I and then enters nitritation / anaerobic ammonium oxidation / denitrification chamber 2 for treatment to obtain wastewater V;

[0080] (5) The wastewater V enters the aerobic MBR tank 3 and circulates steps (3) to (4) until the wastewater index meets the design requirements. The water is filtered through the aerobic tank MBR membrane module 4 and flows into the clear water tank 23.

[0081] The processing system adopted in this embodiment is that the partition 11 in the processing system of Example 1 is set as a wire mesh corrugated sheet 26, and the rest of the structure remains unchanged.

[0082] The treated water was tested and the results were:

[0083] In the water discharged from the system, the COD concentration is 90-100 mg / L, the ammonia nitrogen concentration is 30-40 mg / L, the total nitrogen concentration is 70-90 mg / L, and the dissolved oxygen concentration in the anaerobic ammonium oxidation and denitrification reaction zone 28 is 0.3 mg / L.

[0084] Example 5

[0085] This embodiment adopts the low-carbon, high-ammonia nitrogen wastewater treatment system in Example 2 to treat high-ammonia nitrogen, low carbon-nitrogen ratio wastewater with an average COD concentration of about 1200 mg / L, an average ammonia nitrogen concentration of about 800 mg / L, and an average total nitrogen concentration of 860 mg / L.

[0086] The processing method is:

[0087] (1) Pumping the initial wastewater into the hydrolysis and acidification tank 1 for hydrolysis and acidification treatment to obtain treated wastewater I;

[0088] The average COD concentration of the effluent from hydrolysis and acidification tank 1 is 720 mg / L, the ammonia nitrogen concentration is 760 mg / L, and the total nitrogen concentration is 850 mg / L; the filler filling degree of hydrolysis and acidification tank 1 is 70%, the initial wastewater pH value is 7.6, and the hydraulic retention time is 6 hours;

[0089] (2) Wastewater I enters the nitrification reaction zone 27 from the bottom of the nitrification / anaerobic ammonium oxidation / denitrification chamber 2, and is treated to obtain wastewater II. Wastewater II enters the anaerobic ammonium oxidation and denitrification reaction zone 28, and is treated to obtain wastewater III.

[0090] After treatment, the COD concentration in the nitrite reaction zone 27 was 480 mg / L, the ammonia nitrogen concentration was 190 mg / L, the nitrite nitrogen concentration was 240 mg / L, and the nitrate nitrogen concentration was 16 mg / L. The COD concentration in the anaerobic ammonium oxidation and denitrification reaction zone 28 was 310 mg / L, the ammonia nitrogen concentration was 14 mg / L, the nitrite nitrogen concentration was 20 mg / L, and the nitrate nitrogen concentration was 6 mg / L. The dissolved oxygen concentration in the nitrite reaction zone 27 was 0.7 mg / L, the temperature was 32°C, the dissolved oxygen concentration in the anaerobic ammonium oxidation and denitrification reaction zone 28 was 0.1 mg / L, the pH value was 7.8, and the wire mesh corrugated The filling degree of the three-dimensional elastic fillers 12 on both sides of the sheet 26 is 60%, and the material of the three-dimensional elastic fillers 12 is polypropylene; the coverage rate of the three-dimensional fillers is 70%; the height of the wire mesh corrugated sheet 26 is 80% of the height of the outer side of the anaerobic ammonium oxidation tank; the wire mesh corrugated sheet 26 is made of stainless steel; the hydraulic retention time of the nitritation / anaerobic ammonium oxidation / denitrification chamber 2 is 24 hours; a guide plate 25 is provided on the gas collection hood 24 to guide the water from the nitritation reaction zone 27 into the bottom of the anaerobic ammonium oxidation and denitrification reaction zone 28; the length of the guide plate 25 is set to 1 / 2 of the height of the cylindrical partition 11.

[0091] (3) Wastewater III is pumped into aerobic MBR tank 3 and treated to obtain return wastewater IV;

[0092] The remaining unremoved organic matter and ammonia nitrogen in the wastewater are converted into inorganic matter and ammonia nitrogen into nitrate nitrogen under the aerobic respiration of aerobic microorganisms such as rotifers, bellworms, and nitrifying bacteria in the aerobic MBR pool 3. The wastewater after the reaction is partially returned to the nitrite / anaerobic ammonium oxidation / denitrification chamber 2; the dissolved oxygen concentration in the aerobic MBR pool 3 is about 1.5 mg / L, the residence time is 12 hours, the sludge concentration is 4 g / L, and the reflux ratio is 100%.

[0093] (4) Wastewater IV is mixed with wastewater I and then enters nitritation / anaerobic ammonium oxidation / denitrification chamber 2 for treatment to obtain wastewater V;

[0094] (5) The wastewater V enters the aerobic MBR tank 3 and circulates steps (3) to (4) until the wastewater index meets the design requirements. The water is filtered through the aerobic tank MBR membrane module 4 and flows into the clear water tank 23.

[0095] After testing: the COD concentration in the water discharged from the system is 50-80 mg / L, the ammonia nitrogen concentration is 3-5 mg / L, and the total nitrogen concentration is 30-40 mg / L.

[0096] Comparative Example 1

[0097] The difference between the low-carbon, high-ammonia nitrogen wastewater treatment system in this comparative example and that in Example 1 is that the gas collecting hood 24 and the guide plate 25 in the system are removed, while the remaining structures remain unchanged. This system is used to treat wastewater, and the treatment method and specific parameters are the same as those in Example 5.

[0098] The treated water was tested and the results were:

[0099] In the water discharged from the system, the COD concentration is 80-100 mg / L, the ammonia nitrogen concentration is 30-40 mg / L, the total nitrogen concentration is 70-90 mg / L, and the dissolved oxygen concentration in the anaerobic ammonium oxidation and denitrification reaction zone 28 is 0.5 mg / L.

[0100] Comparative Example 2

[0101] This comparative example uses the same treatment system as Example 5 to treat the wastewater. The treatment method and specific parameters are different from those of Example 5 in that: in step (3), the reflux ratio is set to 0.

[0102] The treated water was tested and the results were: COD concentration 150-200 mg / L, ammonia nitrogen concentration 200-300 mg / L, total nitrogen concentration 700-800 mg / L, and dissolved oxygen concentration in the anaerobic ammonium oxidation and denitrification reaction zone 28 was 0.1 mg / L.

[0103] Compared with Example 5, the removal effects of COD, ammonia nitrogen and total nitrogen in this comparative example are very poor, mainly because the mixed liquor of the aerobic MBR pool 3 is not returned to the partial nitritation reaction zone 27, and the partial nitritation process cannot be achieved, resulting in the anaerobic ammonium oxidation and denitrification reactions cannot proceed smoothly.

[0104] Comparative Example 3

[0105] This comparative example uses the same treatment system as Example 5 to treat wastewater. The treatment method and specific parameters are different from those of Example 5 in that: in step (3), the reflux ratio is set to 200%.

[0106] The treated water was tested and the results were: COD concentration 50-80 mg / L, ammonia nitrogen concentration 8-10 mg / L, total nitrogen concentration 100-120 mg / L, and dissolved oxygen concentration in the anaerobic ammonium oxidation and denitrification reaction zone 28 was 0.5 mg / L.

[0107] Compared with Example 5, the effluent ammonia nitrogen and total nitrogen in this comparative example have an increasing trend. This is mainly because after the reflux ratio becomes larger, the dissolved oxygen in the nitritation reaction zone 27 increases, nitrite nitrogen is converted into nitrate nitrogen, and the anaerobic ammonium oxidation reaction cannot proceed smoothly, resulting in a decrease in the total nitrogen removal rate.

[0108] Comparative Example 4

[0109] This comparative example uses the same treatment system as Example 5 to treat the wastewater. The treatment method and specific parameters differ from those of Example 5 in that: in step (2), the hydraulic retention time of nitritation / anaerobic ammonium oxidation / denitrification chamber 2 is set to 12 h.

[0110] The treated water was tested and the results were: COD concentration 150-200 mg / L, ammonia nitrogen concentration 100-120 mg / L, total nitrogen concentration 120-150 mg / L, and dissolved oxygen concentration in the anaerobic ammonium oxidation and denitrification reaction zone 28 was 0.1 mg / L.

[0111] Compared with Example 5, the COD, ammonia nitrogen and total nitrogen in the effluent of this comparative example all tend to increase, mainly because the residence time of the nitritation / anaerobic ammonium oxidation / denitrification chamber 2 is too short and the hydraulic load is too large, so the nitritation reaction, anaerobic ammonium oxidation reaction and denitrification reaction cannot be fully carried out, resulting in a reduced pollutant removal rate.

[0112] Comparative Example 5

[0113] This comparative example uses the same treatment system as Example 5 to treat the wastewater. The treatment method and specific parameters differ from those of Example 5 in that: in step (2), the hydraulic retention time of nitritation / anaerobic ammonium oxidation / denitrification chamber 2 is set to 48 h.

[0114] The treated water was tested and the results were: COD concentration 50-80 mg / L, ammonia nitrogen concentration 15-30 mg / L, total nitrogen concentration 50-80 mg / L, and dissolved oxygen concentration in the anaerobic ammonium oxidation and denitrification reaction zone 28 was 0.2 mg / L.

[0115] Compared with Example 5, the ammonia nitrogen and total nitrogen removal rates of this comparative example decreased, mainly because the fluidity of the mixed liquid in the nitritation / anaerobic ammonium oxidation / denitrification chamber 2 decreased after the hydraulic retention time was extended, resulting in the inability to fully proceed with the reaction.

[0116] Comparative Example 6

[0117] This comparative example uses the same treatment system as Example 5 to treat wastewater. The treatment method and specific parameters differ from those of Example 5 in that: in step (3), the dissolved oxygen concentration in the aerobic MBR tank 3 is set to about 0.5 mg / L.

[0118] The treated water was tested and the results were: COD concentration 300-500 mg / L, ammonia nitrogen concentration 500-600 mg / L, total nitrogen concentration 600-700 mg / L, and dissolved oxygen concentration in the anaerobic ammonium oxidation and denitrification reaction zone 28 was 0.1 mg / L.

[0119] Compared with Example 5, the COD, ammonia nitrogen and total nitrogen removal rates of this comparative example decreased, mainly because the dissolved oxygen concentration in the aerobic MBR tank 3 was too low, the dissolved oxygen in the nitrite reaction zone 27 was too low, the ammonia nitrogen could not be fully converted into nitrite nitrogen, the anaerobic ammonia oxidation reaction and denitrification could not proceed smoothly, resulting in a reduced pollutant removal rate.

[0120] Comparative Example 7

[0121] This comparative example uses the same treatment system as Example 5 to treat wastewater. The treatment method and specific parameters differ from those of Example 5 in that: in step (3), the dissolved oxygen concentration in the aerobic MBR tank 3 is set to about 3.0 mg / L.

[0122] The treated water was tested and the results were: COD concentration 50-80 mg / L, ammonia nitrogen concentration 8-10 mg / L, total nitrogen concentration 150-180 mg / L, and dissolved oxygen concentration in the anaerobic ammonium oxidation and denitrification reaction zone 28 was 0.5 mg / L.

[0123] Compared with Example 5, the effluent ammonia nitrogen and total nitrogen in this comparative example have an increasing trend. This is mainly because after the reflux ratio becomes larger, the dissolved oxygen in the nitritation reaction zone 27 increases, nitrite nitrogen is converted into nitrate nitrogen, and the anaerobic ammonium oxidation reaction cannot proceed smoothly, resulting in a decrease in the total nitrogen removal rate.

Claims

1. A treatment system for low-carbon high-ammonia nitrogen wastewater, characterized in that: The treatment system comprises a hydrolysis acidification tank (1), a nitrification / anaerobic ammonium oxidation / denitrification chamber (2) and an aerobic MBR tank (3) which are connected in sequence; The hydrolysis and acidification tank (1) is provided with a wastewater inlet, the hydrolysis and acidification tank (1) is connected to the bottom of the nitrification reaction zone (27), and the aerobic MBR tank (3) is provided with a water outlet (20) connected to the outside; The nitrification / anaerobic ammonium oxidation / denitrification chamber (2) includes an inner and outer part separated by a partition (11), the inner part being a nitrification reaction zone (27) and the outer part being an anaerobic ammonium oxidation and denitrification reaction zone (28), and water can flow through the top of the partition (11); the partition (11) is cylindrical or cylindrical with a polygonal cross section, and is composed of a plurality of multi-layer wire mesh corrugated sheets (26); bottle brush-shaped three-dimensional elastic fillers (12) are suspended on the pores on both sides of the surface of the wire mesh corrugated sheet (26), ammonia oxidizing bacteria are enriched on the three-dimensional elastic filler (12) suspended on one side of the nitrification reaction zone (27), and anaerobic ammonium oxidizing bacteria and denitrifying bacteria are enriched on the three-dimensional elastic filler (12) suspended on one side of the anaerobic ammonium oxidation and denitrification reaction zone (28); A gas collecting hood (24) for collecting the gas generated by the nitritation reaction is provided on the top of the nitritation reaction zone (27), and an exhaust pipe (22) is provided and connected to the gas collecting hood (24) to discharge the gas generated by the reaction in the nitritation / anaerobic ammonium oxidation / denitrification chamber (2).

2. The low-carbon high-ammonia nitrogen wastewater treatment system according to claim 1 is characterized in that: A connecting pipe (21) is provided between the nitritation / anaerobic ammonium oxidation / denitrification chamber (2) and the aerobic MBR tank (3), and the connection point between the connecting pipe (21) and the anaerobic ammonium oxidation and denitrification reaction zone (28) is set below the top of the partition (11).

3. The low-carbon high-ammonia nitrogen wastewater treatment system according to claim 2 is characterized in that: A guide plate (25) is provided on the gas collecting hood (24), and the guide plate (25) is used to guide water flowing out from the top of the partition (11) in the nitrite reaction zone (27) toward the bottom of the anaerobic ammonium oxidation and denitrification reaction zone (28).

4. A wastewater treatment method using the low-carbon high-ammonia nitrogen wastewater treatment system according to any one of claims 1 to 3, characterized in that: The following steps are involved: (1) Pumping the initial wastewater into the hydrolysis and acidification tank for hydrolysis and acidification treatment to obtain wastewater I; (2) Wastewater I enters the nitrification reaction zone from the bottom of the nitrification / anaerobic ammonium oxidation / denitrification chamber, and after treatment, wastewater II is obtained. Wastewater II enters the anaerobic ammonium oxidation and denitrification reaction zone, and after treatment, wastewater II I is obtained. (3) Pump wastewater II into the aerobic MBR tank and obtain wastewater IV after treatment; (4) Wastewater IV is mixed with wastewater I and then enters the nitrification / anaerobic ammonium oxidation / denitrification chamber for treatment to obtain wastewater V; (5) Repeat steps (3) to (4) until the wastewater index meets the design requirements, and the treated water is discharged from the outlet to the clean water tank.

5. The processing method according to claim 4, characterized in that In step (1), the initial influent pH value is 7.5-8, and the C / N ratio is 1-3.

6. The processing method according to claim 4, characterized in that In step (2), the hydraulic retention time in the nitritation / anaerobic ammonium oxidation / denitrification chamber is 24 h to 36 h.

7. The processing method according to claim 4, wherein In step (2), the temperature of the nitritation reaction zone is 32-34° C.; the dissolved oxygen in the nitritation reaction zone is 0.5-1.0 mg / L, and the dissolved oxygen in the anaerobic ammonium oxidation and denitrification reaction zone is 0-0.3 mg / L.

8. The processing method according to claim 4, wherein In step (3), the dissolved oxygen in the aerobic MBR tank is 1-2 mg / L; and the reflow ratio of the wastewater in the aerobic MBR tank is 50-150%.

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