Wastewater treatment process based on anaerobic ammonia oxidation
By combining pretreatment, hydrolysis acidification, and dissimilar iron reduction with a short-cut nitrification-anaerobic ammonia oxidation process, the problems of slow bacterial proliferation and water quality fluctuations in the treatment of high ammonia nitrogen wastewater were solved, achieving efficient and low-cost wastewater treatment.
Patent Information
- Application Number
- CN202511036063.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-26
- Publication Date
- 2025-12-12
AI Technical Summary
Existing wastewater treatment methods based on anaerobic ammonia oxidation suffer from problems such as slow bacterial proliferation, difficulty in reactor start-up, large fluctuations in water quality, and decreased sludge activity when treating high ammonia nitrogen wastewater, resulting in low treatment efficiency and high cost.
A combined process of pretreatment, hydrolysis acidification, dissimilar iron reduction, short-cut nitrification, and anaerobic ammonia oxidation is adopted. By coupling dissimilar iron reducing bacteria with short-cut nitrification-anaerobic ammonia oxidation, high-ammonia nitrogen wastewater can be treated efficiently. The dissimilar iron reducing bacteria degrade humic acid and provide a carbon source, promoting the rapid start-up of nitrite and anaerobic ammonia oxidation.
It achieves efficient and low-cost wastewater treatment, with ammonia nitrogen removal rate of over 90%, total nitrogen removal rate of 85%, reduced sludge production, good operational stability, and short start-up time.
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to an industrial wastewater treatment process, in particular to an industrial wastewater treatment process based on dissimilatory iron reduction and anaerobic ammonia oxidation, and belongs to the technical field of wastewater treatment. BACKGROUND
[0002] High ammonia-nitrogen wastewater represented by late landfill leachate, livestock and poultry wastewater after anaerobic treatment and pharmaceutical wastewater is difficult to achieve standard discharge of effluent ammonia-nitrogen and total nitrogen through conventional biochemical treatment due to imbalance of C / N ratio, and thus usually needs to add carbon source to adjust water quality to improve the effect of biochemical treatment, which greatly increases the treatment cost. In view of the above problems, the anaerobic ammonia oxidation process can effectively improve the effluent water quality of wastewater without adding carbon source to achieve standard discharge, and therefore, using the anaerobic ammonia oxidation process to treat high ammonia-nitrogen wastewater has become a research hotspot in the field.
[0003] However, the existing wastewater treatment method based on anaerobic ammonia oxidation still has the following defects: due to the complex composition of high ammonia-nitrogen wastewater, the water quality changes greatly, and the content of humic acid and SS and other components is very high, which is not conducive to the rapid growth of anaerobic ammonia oxidation bacteria, resulting in slow proliferation of the bacteria, and it is difficult to quickly start the reactor, and at the same time, if the water quality changes greatly, it is also easy to cause the activity of anaerobic ammonia oxidation sludge to decrease, thereby reducing the treatment efficiency of the wastewater.
[0004] Therefore, how to effectively reduce the adverse effects of influent water quality on anaerobic ammonia oxidation active sludge is the key to efficiently treating ammonia-nitrogen wastewater by using the anaerobic ammonia oxidation process. SUMMARY
[0005] The present application provides a wastewater treatment process based on anaerobic ammonia oxidation to solve the problems of the existing wastewater treatment method based on anaerobic ammonia oxidation, which is convenient to operate, has short start-up time, low treatment cost, high treatment efficiency, wide water quality application range and good running stability.
[0006] The technical solution of the present application to solve the above technical problems is as follows:
[0007] A wastewater treatment process based on anaerobic ammonia oxidation, comprising the following steps:
[0008] (1) Pretreatment: the wastewater to be treated is self-flowed into a flocculation tank after passing through a grating inclined screen, and after flocculation and sedimentation, solid-liquid separation is performed;
[0009] (2) Hydrolysis acidification: the effluent from the flocculation tank is introduced into a hydrolysis acidification tank, and the organic matter in the wastewater is decomposed and part of the COD is removed through anaerobic hydrolysis acidification;
[0010] (3) dissimilatory iron reduction: introducing the effluent of the hydrolysis acidification tank into an anaerobic dissimilatory iron reduction tank, maintaining the concentration of Fe 3+ 10-40 mmol / L in the dissimilatory iron reduction tank, and providing carriers or fillers loaded with dissimilatory iron reduction bacteria, the dissimilatory iron reduction bacteria comprising Pseudochrobactrum asaccharolyticum and Clostridium butyricum, the Pseudochrobactrum asaccharolyticum being preserved in the China General Microbiological Culture Collection Center with a preservation number of CGMCC No. 28059, the concentration of sludge in the dissimilatory iron reduction process being 1-2 g / L, the pH value of the system in the dissimilatory iron reduction process being controlled to be 7-9, the oxidation-reduction potential being controlled to be -0.7 to -0.2 V, and the residence time being 4-7 days;
[0011] (4) primary sedimentation: introducing the effluent of the dissimilatory iron reduction tank into a primary sedimentation tank for sedimentation, and returning the solid material after the sedimentation to the dissimilatory iron reduction tank;
[0012] (5) short-cut nitrification-anammox: introducing the effluent of the primary sedimentation tank into a short-cut nitrification reactor for nitritation treatment until the mass ratio of ammonia nitrogen to nitrite nitrogen is 1:(1.1-1.5), and then introducing the effluent of the short-cut nitrification reactor into an anammox reactor, so that the ammonia nitrogen and the nitrite nitrogen undergo anammox reaction under the action of red bacteria to generate nitrogen gas;
[0013] (6) secondary sedimentation: introducing the effluent of the anammox reactor into a secondary sedimentation tank, returning the solid material after the sedimentation to the anammox reactor, and discharging the supernatant.
[0014] Further, the residence time of the hydrolysis acidification in step (2) is 8-20 hours.
[0015] Further, the carrier in step (3) is one or more of carbon fibers, sand or activated carbon.
[0016] Further, the Clostridium butyricum in step (3) can be purchased from any manufacturer on the market.
[0017] Further, the concentration of nitritation sludge in the nitritation process in step (5) is 6-8 g / L, the pH value of the system is controlled to be 7-9, and the concentration of dissolved oxygen is 0.1-0.5 mg / L.
[0018] Further, the concentration of anammox sludge in the anammox reactor in step (5) is 3-5 g / L, the pH value of the system is controlled to be 7-9, and the concentration of dissolved oxygen is ≤0.05 mg / L.
[0019] Further, the residence time of the short-cut nitrification reaction in step (5) is 1-3 days, and the residence time of the anaerobic ammonia oxidation reaction is 1-5 days.
[0020] The wastewater treatment process provided by the present application has the following beneficial effects:
[0021] (1) After the high-ammonia-nitrogen wastewater is treated by the dissimilatory iron reduction procedure, the biochemical degradation of humic acid substances in the wastewater can be realized by using dissimilatory iron-reducing bacteria, and the Fe 3+ in the wastewater can be reduced, which can meet the water quality requirements of the subsequent short-cut nitrification reaction, reduce the impact of water quality fluctuation on the subsequent nitrosation and anaerobic ammonia oxidation sludge, and thus facilitate the promotion of the nitrosation reaction and the rapid start of the anaerobic ammonia oxidation treatment.
[0022] (2) The hydrolysis acidification procedure hydrolyzes the macromolecular organic substances (such as proteins, fats, sugars, etc.) in the wastewater into small-molecule nutrients (small-molecule alcohols and acids), and the hydrolysis products can be used as carbon sources for the subsequent dissimilatory iron reduction and short-cut nitrification reaction, thereby realizing the resource utilization of the carbon sources in the wastewater.
[0023] (3) The process of coupling the short-cut nitrification with the anaerobic ammonia oxidation is used to treat the wastewater, and the denitrification efficiency is high. In actual engineering applications, the ammonia-nitrogen removal rate is more than 90%, the total nitrogen removal rate is more than 85%, no additional carbon source is needed to adjust the water quality, the sludge yield is only 10% of that of the traditional denitrification process under the same load, and the operation cost is greatly reduced. DETAILED DESCRIPTION
[0024] The principles and characteristics of the present application are described below in conjunction with examples, which are only used to explain the present application and not to limit the scope of the present application.
[0025] Before the present process is formally applied, the short-cut nitrification reactor and the anaerobic ammonia oxidation reactor need to be started by debugging, and the debugging and starting process is as follows:
[0026] (1) Pretreatment: Take the old landfill leachate from a landfill in Jiangsu, and the water quality indexes of the leachate are as follows: COD 2400-2500 mg / L, ammonia nitrogen 1500-1600 mg / L, nitrite nitrogen <5 mg / L, nitrate nitrogen <3 mg / L, and B / C 0.17-0.20. The wastewater to be treated is introduced into the flocculation tank by gravity after passing through a grating inclined screen, and a flocculant is added to the flocculation tank to perform flocculation and sedimentation, thereby removing the oil and SS in the wastewater.
[0027] (2) Hydrolysis acidification: The effluent from the flocculation tank is introduced into the hydrolysis acidification tank, which is filled with activated sludge, and the wastewater is kept in the hydrolysis acidification tank for 12-14 hours, so that the macromolecular organic substances in the wastewater are decomposed into small-molecule alcohols and acids by anaerobic hydrolysis acidification, and part of the COD is removed.
[0028] (3) dissimilatory iron reduction: the effluent of the hydrolysis acidification tank is introduced into a dissimilatory iron reduction tank, the concentration of Fe 3+ in the tank is maintained at 10-20 mmol / L, fillers are arranged in the tank, and a dissimilatory iron reduction bacterial agent 200-500 ppm is added to the tank, the dissimilatory iron reduction bacterial agent is compounded by Pseudogulbenkiania nigrificans and Clostridium butyricum in a ratio of 1:1 in terms of viable bacterial amount, the dissimilatory iron reduction bacterial agent is supplemented every other week, the residence time is 4-5 days, the pH value of the system is controlled at 7-9, and the oxidation-reduction potential is controlled at -0.7 to -0.2 V;
[0029] (4) primary sedimentation: the effluent of the dissimilatory iron reduction tank is introduced into a primary sedimentation tank for sedimentation, sodium hydroxide is added to the primary sedimentation tank to precipitate Fe 3+ and Fe 2+ in the wastewater, and the precipitated solid materials are returned to the dissimilatory iron reduction tank for reuse;
[0030] (5) short-cut nitrification-anammox: the effluent of the primary sedimentation tank is introduced into a short-cut nitrification reactor, the wastewater is subjected to nitritation treatment, the pH value of the system is controlled at 7-9, and the dissolved oxygen concentration is controlled at 0.1-0.5 mg / L, the wastewater is subjected to nitritation treatment until the mass ratio of ammonia nitrogen to nitrite nitrogen is 1:1.2, then the effluent of the short-cut nitrification reactor is introduced into an anammox reactor, the pH value of the system is controlled at 7-9, and the dissolved oxygen concentration is controlled at ≤0.05 mg / L, and the ammonia nitrogen and the nitrite nitrogen undergo anammox reaction to generate nitrogen gas under the action of red bacteria;
[0031] (6) secondary sedimentation: the effluent of the anammox reactor is introduced into a secondary sedimentation tank, the precipitated solid materials are returned to the anammox reactor, and the upper clear liquid can be discharged.
[0032] After the above process is continuously operated for 40-45 days, the anammox sludge concentration is increased to 6-8 g / L, the denitrification load of the anammox reactor exceeds 0.6 kgN / m 3 *d, and the effluent indicators are stable and meet the standards.
[0033] Example 1:
[0034] A wastewater treatment process based on anammox includes the following steps:
[0035] (1) Pretreatment: take the old landfill leachate from a landfill in Jiangsu, the water quality index of the leachate is: COD 2400-2500 mg / L, ammonia nitrogen 1500-1600 mg / L, nitrite nitrogen <5 mg / L, nitrate nitrogen <3 mg / L, B / C 0.17-0.20, the wastewater to be treated is introduced into the flocculation tank by gravity after being screened by the grid inclined screen, and a flocculant is added to the flocculation tank for flocculation and sedimentation to remove oil and SS in the wastewater;
[0036] (2) Hydrolysis acidification: the effluent from the flocculation tank is introduced into the hydrolysis acidification tank, and stays in the hydrolysis acidification tank for 12-14 hours, so that the macromolecular organic matter in the wastewater is decomposed into small molecular alcohol and acid by anaerobic hydrolysis acidification, and part of the COD is removed;
[0037] (3) Dissimilatory iron reduction: the effluent from the hydrolysis acidification tank is introduced into the dissimilatory iron reduction tank, the concentration of Fe 3+ in the tank is maintained at 10-20 mmol / L, the tank is provided with a filler loaded with dissimilatory iron reduction bacteria biofilm, the sludge concentration is 1-2 g / L, the pH value of the system is controlled at 7-9, and the oxidation-reduction potential is-0.7 to-0.2 V, the dissimilatory iron reduction bacteria are compounded by Pseudogulbenkiania nana and Clostridium butyricum according to the live bacteria amount 1:1, the residence time is 4-5 days, and the water quality of the wastewater treated by dissimilatory iron reduction is: COD 700-800 mg / L, ammonia nitrogen 1350-1400 mg / L, nitrite nitrogen <3 mg / L, nitrate nitrogen <3 mg / L, B / C 0.14-0.19;
[0038] (4) Primary sedimentation: the effluent from the dissimilatory iron reduction tank is introduced into the primary sedimentation tank for sedimentation, sodium hydroxide is added to the primary sedimentation tank to precipitate Fe 3+ and Fe 2+ in the wastewater, and the precipitated solid material is recycled to the dissimilatory iron reduction tank for reuse;
[0039] (5) Short-cut nitrification-anaerobic ammonia oxidation: the effluent from the primary sedimentation tank is introduced into the short-cut nitrification reactor, and the wastewater is subjected to nitritation treatment, the concentration of nitritation sludge during the nitritation treatment is 6-8 g / L, the pH value of the system is controlled at 7-9, and the dissolved oxygen concentration is 0.1-0.5 mg / L, the wastewater is subjected to nitritation treatment until the mass ratio of ammonia nitrogen to nitrite nitrogen is 1:(1.2-1.3), then the effluent from the short-cut nitrification reactor is introduced into the anaerobic ammonia oxidation reactor, the concentration of anaerobic ammonia oxidation sludge is controlled at 3-5 g / L, the pH value of the system is 7-9, and the dissolved oxygen concentration is ≤0.05 mg / L, ammonia nitrogen and nitrite nitrogen undergo anaerobic ammonia oxidation reaction to generate nitrogen gas under the action of red bacteria; the water quality of the wastewater treated by anaerobic ammonia oxidation is: COD 50-100 mg / L, ammonia nitrogen 100-120 mg / L, and total nitrogen 200-240 mg / L;
[0040] (6) Secondary sedimentation: The effluent from the anaerobic ammonia oxidation reactor is introduced into the secondary sedimentation tank. The precipitated solid matter is returned to the anaerobic ammonia oxidation reactor. The supernatant is then discharged as effluent. The effluent quality is COD 30-70 mg / L, ammonia nitrogen 80-100 mg / L, and total nitrogen 180-200 mg / L.
[0041] Example 2:
[0042] A wastewater treatment process based on anaerobic ammonia oxidation includes the following steps:
[0043] (1) Pretreatment: Take the pharmaceutical wastewater from a pharmaceutical company in Shandong Province. The water quality indicators of the pharmaceutical wastewater are: COD 3000-3100mg / L, ammonia nitrogen 1200-1300mg / L, nitrite nitrogen 40-50mg / L, nitrate nitrogen 200-300mg / L, B / C 0.23-0.25. After passing through the inclined screen, the wastewater to be treated flows into the flocculation tank by gravity. Flocculant is added to the tank for flocculation and sedimentation to remove oil and SS from the wastewater.
[0044] (2) Hydrolysis acidification: The effluent from the flocculation tank is introduced into the hydrolysis acidification tank and left in the hydrolysis acidification tank for 18-20 hours. The large molecular organic matter in the wastewater is decomposed into small molecular alcohols and acids through anaerobic hydrolysis acidification, and some COD is removed.
[0045] (3) Dissimilar iron reduction: The effluent from the hydrolysis acidification tank is introduced into the dissimilar iron reduction tank to maintain the Fe content in the tank. 3+ The concentration of the sludge was 30-40 mmol / L. The tank was filled with packing material loaded with biofilm of dissimilar iron reducing bacteria. The sludge concentration was 1-2 g / L. The pH of the system was controlled at 7-9 and the oxidation-reduction potential was -0.7 to -0.2 V. The dissimilar iron reducing bacteria were composed of *Pseudomonas aeruginosa* and *Clostridium butyricum* in a 1:1 ratio of live bacteria. The retention time was 6-7 days. The wastewater quality after dissimilar iron reduction treatment was as follows: COD 850-1000 mg / L, ammonia nitrogen 1000-1100 mg / L, nitrite nitrogen 20-30 mg / L, nitrate nitrogen 150-200 mg / L, and B / C 0.22-0.24.
[0046] (4) Primary sedimentation: The effluent from the dissimilar iron reduction tank is introduced into the primary sedimentation tank for sedimentation. Sodium hydroxide is added to the primary sedimentation tank to remove Fe from the wastewater. 3+ and Fe 2+ The precipitated solid material is then returned to the iron reduction tank for reuse.
[0047] (5) Short-cut nitrification-anaerobic ammonium oxidation: The effluent from the primary sedimentation tank is introduced into the short-cut nitrification reactor for nitrification treatment. During the nitrification process, the concentration of nitrified sludge is 6-8 g / L, the pH of the system is controlled at 7-9, and the dissolved oxygen concentration is 0.1-0.5 mg / L. The wastewater is nitrified until the mass ratio of ammonia nitrogen to nitrite nitrogen is 1:(1.2-1.3). Then, the effluent from the short-cut nitrification reactor is introduced into the anaerobic ammonium oxidation reactor. The concentration of anaerobic ammonium oxidation sludge is controlled at 3-5 g / L, the pH of the system is controlled at 7-9, and the dissolved oxygen concentration is ≤0.05 mg / L. Ammonia nitrogen and nitrite nitrogen undergo anaerobic ammonium oxidation under the action of red bacteria to generate nitrogen gas. After anaerobic ammonium oxidation treatment, the wastewater quality is: COD 100-200 mg / L, ammonia nitrogen 100-120 mg / L, and total nitrogen 130-150 mg / L.
[0048] (6) Secondary sedimentation: The effluent from the anaerobic ammonia oxidation reactor is introduced into the secondary sedimentation tank. The precipitated solid matter is returned to the anaerobic ammonia oxidation reactor. The supernatant is then discharged as effluent. The effluent quality is COD 80-100 mg / L, ammonia nitrogen 80-100 mg / L, and total nitrogen 120-130 mg / L.
[0049] Example 3:
[0050] A wastewater treatment process based on anaerobic ammonia oxidation includes the following steps:
[0051] (1) Pretreatment: Take the livestock and poultry wastewater from a large livestock and poultry farm in Shandong Province after anaerobic treatment. The water quality indicators of the wastewater are: COD 2600-2800mg / L, ammonia nitrogen 1800-1900mg / L, nitrite nitrogen 30-40mg / L, nitrate nitrogen 100-200mg / L, B / C 0.25-0.30. After passing through the inclined screen, the wastewater to be treated flows into the flocculation tank by gravity. Flocculant is added to the tank for flocculation and sedimentation to remove oil and SS from the wastewater.
[0052] (2) Hydrolysis acidification: The effluent from the flocculation tank is introduced into the hydrolysis acidification tank and left in the hydrolysis acidification tank for 8-12 hours. The large molecular organic matter in the wastewater is decomposed into small molecular alcohols and acids through anaerobic hydrolysis acidification, and some COD is removed.
[0053] (3) Dissimilar iron reduction: The effluent from the hydrolysis acidification tank is introduced into the dissimilar iron reduction tank to maintain the Fe content in the tank. 3+The concentration of the agent is 10-20 mmol / L. The tank is filled with packing material loaded with biofilm of dissimilar iron reducing agent. The sludge concentration is 1-2 g / L. The pH of the system is controlled at 7-9 and the oxidation-reduction potential is -0.7 to -0.2 V. The dissimilar iron reducing agent is composed of *Pseudomonas aeruginosa* and *Clostridium butyricum* in a 1:1 ratio of live bacteria. The retention time is 4-5 days. The wastewater quality after dissimilar iron reduction treatment is as follows: COD 600-750 mg / L, ammonia nitrogen 1300-1400 mg / L, nitrite nitrogen 30-40 mg / L, nitrate nitrogen 100-150 mg / L, B / C 0.25-0.30.
[0054] (4) Primary sedimentation: The effluent from the dissimilar iron reduction tank is introduced into the primary sedimentation tank for sedimentation. Sodium hydroxide is added to the primary sedimentation tank to remove Fe from the wastewater. 3+ and Fe 2+ The precipitated solid material is then returned to the iron reduction tank for reuse.
[0055] (5) Short-cut nitrification-anaerobic ammonium oxidation: The effluent from the primary sedimentation tank is introduced into the short-cut nitrification reactor for nitrification treatment. During the nitrification process, the concentration of nitrified sludge is 6-8 g / L, the pH of the system is controlled at 7-9, and the dissolved oxygen concentration is 0.1-0.5 mg / L. The wastewater is nitrified until the mass ratio of ammonia nitrogen to nitrite nitrogen is 1:(1.2-1.3). Then, the effluent from the short-cut nitrification reactor is introduced into the anaerobic ammonium oxidation reactor. The concentration of anaerobic ammonium oxidation sludge is controlled at 3-5 g / L, the pH of the system is controlled at 7-9, and the dissolved oxygen concentration is ≤0.05 mg / L. Ammonia nitrogen and nitrite nitrogen undergo anaerobic ammonium oxidation under the action of red bacteria to generate nitrogen gas. After anaerobic ammonium oxidation treatment, the wastewater quality is: COD 50-100 mg / L, ammonia nitrogen 120-140 mg / L, and total nitrogen 180-200 mg / L.
[0056] (6) Secondary sedimentation: The effluent from the anaerobic ammonia oxidation reactor is introduced into the secondary sedimentation tank. The settled solid matter is returned to the anaerobic ammonia oxidation reactor. The supernatant is then discharged as effluent. The effluent quality is COD 50-80 mg / L, ammonia nitrogen 100-120 mg / L, and total nitrogen 130-150 mg / L.
[0057] Comparative Example 1:
[0058] A wastewater treatment process based on anaerobic ammonia oxidation includes the following steps:
[0059] (1) Pretreatment: Take the leachate from an old landfill in Jiangsu Province. The water quality indicators of the leachate are: COD 2400-2500mg / L, ammonia nitrogen 1500-1600mg / L, nitrite nitrogen <5mg / L, nitrate nitrogen <3mg / L, B / C 0.17-0.20. After passing through the inclined screen, the wastewater to be treated flows into the flocculation tank by gravity. Flocculant is added to the tank for flocculation and sedimentation to remove oil and SS from the wastewater.
[0060] (2) Hydrolysis acidification: The effluent from the flocculation tank is introduced into the hydrolysis acidification tank and left in the hydrolysis acidification tank for 12-14 hours. The large molecular organic matter in the wastewater is decomposed into small molecular alcohols and acids through anaerobic hydrolysis acidification, and some COD is removed.
[0061] (3) Primary sedimentation: The effluent from the hydrolysis acidification tank is introduced into the primary sedimentation tank for sedimentation. The solid matter after sedimentation is returned to the hydrolysis acidification tank for reuse. The wastewater quality after primary sedimentation is: COD 2000-2100mg / L, ammonia nitrogen 1300-1400mg / L, nitrite nitrogen <3mg / L, nitrate nitrogen <3mg / L, B / C 0.30-0.0.35.
[0062] (4) Short-cut nitrification-anaerobic ammonium oxidation: The effluent from the primary sedimentation tank is introduced into the short-cut nitrification reactor for nitrification treatment. During the nitrification process, the concentration of nitrified sludge is 6-8 g / L, the pH of the system is controlled at 7-9, and the dissolved oxygen concentration is 0.1-0.5 mg / L. The wastewater is nitrified until the mass ratio of ammonia nitrogen to nitrite nitrogen is 1:(1.2-1.3). Then, the effluent from the short-cut nitrification reactor is introduced into the anaerobic ammonium oxidation reactor, and the concentration of anaerobic ammonium oxidation sludge is controlled at 3-5 g / L, the pH of the system is controlled at 7-9, and the dissolved oxygen concentration is ≤0.05 mg / L. Ammonia nitrogen and nitrite nitrogen undergo anaerobic ammonium oxidation under the action of red bacteria to generate nitrogen gas. The wastewater quality after anaerobic ammonium oxidation treatment is: COD 1800-1900 mg / L, ammonia nitrogen 1000-1100 mg / L, total nitrogen 1200-1300 mg / L;
[0063] (5) Secondary sedimentation: The effluent from the anaerobic ammonia oxidation reactor is introduced into the secondary sedimentation tank. The settled solid matter is returned to the anaerobic ammonia oxidation reactor. The effluent quality of the supernatant is COD 1600-1700mg / L, ammonia nitrogen 1000-1100mg / L, and total nitrogen 1100-1200mg / L.
[0064] The comparison of the application effects of Examples 1-3 and Comparative Example 1 shows that, by adopting the coupled process of "hydrolysis acidification + dissimilar iron reduction + anaerobic ammonium oxidation" of the present invention, on the one hand, the organic matter present in the raw water is fully utilized, and the products of hydrolysis acidification are used as carbon sources for subsequent processes. On the other hand, the dissimilar iron reduction process realizes the biochemical degradation of humic acid substances in wastewater, reduces the impact of water quality fluctuations on nitrification and anaerobic ammonium oxidation sludge, shortens the start-up time of nitrification reactor and anaerobic ammonium oxidation reactor by 1 / 3 compared with the prior art, greatly improves the treatment capacity, and produces sludge particles with good morphology. In engineering applications, the ammonia nitrogen removal rate reaches more than 90%, the total nitrogen removal rate reaches more than 85%, and the sludge production is only 10% of that of the traditional denitrification process under the same load, greatly reducing the operating cost.
[0065] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.
Claims
1. A wastewater treatment process based on anaerobic ammonia oxidation, characterized in that, Includes the following steps: (1) Pretreatment: The wastewater to be treated flows into the flocculation tank by gravity after passing through the inclined screen of the grid, and then undergoes solid-liquid separation after flocculation and sedimentation. (2) Hydrolysis acidification: The effluent from the flocculation tank is introduced into the hydrolysis acidification tank, and the organic matter in the wastewater is decomposed and some COD is removed through anaerobic hydrolysis acidification. (3) Dissimilar iron reduction: The effluent from the hydrolysis acidification tank is introduced into an anaerobic dissimilar iron reduction tank, wherein Fe is maintained in the dissimilar iron reduction tank. 3+ The concentration of the sludge is 10-40 mmol / L, and a carrier or packing material loaded with a biofilm of dissimilar iron reducing agent is provided. The dissimilar iron reducing agent includes *Pseudochrobactrum asaccharolyticum* and *Clostridium butyricum*. The *Pseudochrobactrum asaccharolyticum* is deposited at the China General Microbiological Culture Collection Center (CGMCC) with accession number CGMCC No. 28059. The concentration of sludge during the dissimilar iron reduction treatment is 1-2 g / L. The pH value of the system is controlled at 7-9, the redox potential at -0.7 to -0.2 V, and the residence time at 4-7 days during the dissimilar iron reduction treatment. (4) Primary sedimentation: The effluent from the iron reduction tank is introduced into the primary sedimentation tank for sedimentation, and the solid matter after sedimentation is returned to the iron reduction tank. (5) Short-cut nitrification-anaerobic ammonia oxidation: The effluent from the primary sedimentation tank is introduced into the short-cut nitrification reactor to treat the wastewater with nitrite until the mass ratio of ammonia nitrogen to nitrite nitrogen is 1:(1.1-1.5). Then the effluent from the short-cut nitrification reactor is introduced into the anaerobic ammonia oxidation reactor, where ammonia nitrogen and nitrite nitrogen undergo anaerobic ammonia oxidation under the action of red bacteria to generate nitrogen gas. (6) Secondary sedimentation: The effluent from the anaerobic ammonia oxidation reactor is introduced into the secondary sedimentation tank. The precipitated solid matter is returned to the anaerobic ammonia oxidation reactor, and the supernatant is discharged.
2. The wastewater treatment process according to claim 1, characterized in that, In step (5), the concentration of nitrified sludge during the nitrification process is 6-8 g / L, the pH of the system is controlled at 7-9, and the dissolved oxygen concentration is 0.1-0.5 mg / L.
3. The wastewater treatment process according to claim 1, characterized in that, In step (5), the concentration of anaerobic ammonia oxidation sludge in the anaerobic ammonia oxidation reactor is 3-5 g / L, the pH of the system is controlled at 7-9, and the dissolved oxygen concentration is ≤0.05 mg / L.
4. The wastewater treatment process according to any one of claims 1-3, characterized in that, The carrier mentioned in step (3) is one or more of carbon fiber, sand or activated carbon.
5. The wastewater treatment process according to any one of claims 1-3, characterized in that, The residence time for hydrolysis and acidification in step (2) is 8-20 hours.
6. The wastewater treatment process according to any one of claims 1-3, characterized in that, The residence time for the short-range nitration reaction described in step (5) is 1-3 days.
7. The wastewater treatment process according to any one of claims 1-3, characterized in that, The residence time for the anaerobic ammonia oxidation reaction described in step (5) is 1-5 days.
8. The wastewater treatment process according to any one of claims 1-3, characterized in that, The Clostridium butyricum mentioned in step (3) can be purchased from any manufacturer's product or strain on the market.