High organic nitrogen low-temperature continuous flow AOA treatment method and device

Abstract

The application provides a high-organic-nitrogen low-temperature continuous-flow AOA treatment method and device, and belongs to the technical field of wastewater treatment. The application discloses a high-organic-nitrogen low-temperature continuous-flow AOA treatment method and device, and belongs to the technical field of wastewater treatment. The application discloses a high-organic-nitrogen low-temperature continuous-flow AOA treatment method and device, and belongs to the technical field of wastewater treatment. The application discloses a high-organic-nitrogen low-temperature continuous-flow AOA treatment method and device, and belongs to the technical field of wastewater treatment. The application discloses a high-organic-nitrogen low-temperature continuous-flow AOA treatment method and device, and belongs to the technical field of wastewater treatment. The application discloses a high-organic-nitrogen low-temperature continuous-flow AOA treatment method and device, and belongs to the technical field of wastewater treatment. The application discloses a high-organic-nitrogen low-temperature continuous-flow AOA treatment method and device, and belongs to the technical field of wastewater treatment. The application discloses a high-organic-nitrogen low-temperature continuous-flow AOA treatment method and device, and belongs to the technical field of wastewater treatment. The application discloses a high-organic-nitrogen low-temperature continuous-flow AOA treatment method and device, and belongs to the technical field of wastewater treatment. The application discloses a high-organic-nitrogen low-temperature continuous-flow AOA treatment method and device, and belongs to the technical field of wastewater treatment. The application discloses a high-organic-nitrogen low-temperature continuous-flow AOA treatment method and device, and belongs to the technical field of wastewater treatment. The application discloses a high-organic-nitrogen low-temperature continuous-flow AOA treatment method and device, and belongs to the technical field of wastewater treatment. The application discloses a high-organic-nitrogen low-temperature continuous-flow AOA treatment method and device, and belongs to the technical field of wastewater treatment. The application discloses a high-organic-nitrogen low-temperature continuous-flow AOA treatment method and device, and belongs to the technical field of wastewater treatment. The application discloses a high-organic-nitrogen low-temperature continuous-flow AOA treatment method and device, and belongs to the technical field of wastewater treatment. The application

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of wastewater treatment, and particularly relates to a high-organic-nitrogen low-temperature continuous-flow AOA treatment method and device. BACKGROUND

[0002] With water resource shortage and limited water environment capacity, the discharge standards for sewage treatment, especially the requirements for nitrogen and phosphorus indicators, are becoming increasingly stringent. Some municipal sewage treatment plants have industrial wastewater mixed in them, which has three notable and interrelated characteristics: high proportion of organic nitrogen, low carbon-nitrogen ratio, and low temperature in winter. The three factors together make it difficult for sewage treatment plants using traditional biological denitrification and phosphorus removal processes to operate stably, and the plants face the dilemma of low efficiency, large carbon source dosage, and large sludge production, which requires urgent process upgrading.

[0003] The A 2 O and multi-stage AO processes widely used in sewage treatment plants have some drawbacks, such as inhibition of anaerobic phosphorus release by nitrate nitrogen carried by reflux sludge, destruction of anoxic denitrification environment by high dissolved oxygen carried by reflux nitrification liquid, and high reflux energy consumption, which makes it difficult for the effluent to meet the nitrogen and phosphorus standards.

[0004] The AOA (anaerobic-aerobic-anoxic) process, as an innovative variant of the double-sludge system, provides a new idea for solving the above problems by changing the order of the reaction zones. The process places the aerobic section after the anaerobic section and before the anoxic section, which has potential advantages. First, it allows phosphorus-accumulating bacteria to fully release phosphorus in the anaerobic zone and then absorb excess phosphorus in the first aerobic zone, achieving rapid phosphorus removal. Second, the nitrate nitrogen produced in the aerobic zone can directly enter the subsequent anoxic zone for denitrification.

[0005] However, the current AOA process still faces many unsolved technical problems when directly applied to special water quality with industrial wastewater mixed in, as follows:

[0006] (1) Under the background of high proportion of organic nitrogen, how to ensure efficient coupling of the ammoniation process of organic nitrogen and the nitrification / denitrification process in terms of time and space, and avoid the denitrification bottleneck caused by delayed ammoniation.

[0007] (2) Under the condition of low carbon-nitrogen ratio, how to accurately regulate the working conditions to enrich denitrifying phosphorus-accumulating bacteria (DPAOs) and denitrifying glycogen-accumulating bacteria (DGAOs), so that they can use nitrate nitrogen as an electron acceptor to simultaneously complete denitrification and phosphorus removal, achieve "one-carbon dual-use" of internal carbon sources, and thus alleviate the carbon source competition contradiction.

[0008] (3) How to enhance the competitive advantage and metabolic activity of functional bacteria (especially DPAOs) at low temperatures, and improve the overall low-temperature resistance of the system.

[0009] Therefore, the prior art lacks an AOA process that can specifically solve the three core contradictions of wastewater having a high proportion of organic nitrogen, a low carbon-nitrogen ratio, and low temperature. SUMMARY

[0010] The embodiment of the present application provides a high-organic-nitrogen low-temperature continuous-flow AOA treatment method and device based on short-range nitrifying bacteria embedding, aiming to solve the contradictions in the treatment of wastewater with a high proportion of organic nitrogen, a low carbon-nitrogen ratio, and low temperature and doped with industrial wastewater.

[0011] The problems of denitrification bottleneck caused by delayed ammoniation of wastewater under the condition of a high proportion of organic nitrogen, the contradiction of carbon source competition under the condition of a low carbon-nitrogen ratio, and poor metabolic activity of wastewater under low temperature.

[0012] In a first aspect, to achieve the above object, the technical scheme adopted by the present application is to provide a high-organic-nitrogen low-temperature continuous-flow AOA treatment method, which comprises the following steps:

[0013] The final treatment mixed liquor formed after the low-temperature wastewater sequentially passes through a hydrolysis acidification zone, an anaerobic zone, an anaerobic-aerobic variable zone, an aerobic zone, an aerobic-anoxic variable zone, an anoxic zone, and an anoxic-aerobic variable zone is introduced into a secondary sedimentation tank for sedimentation and separation, and the supernatant clear water reaches the discharge standard and is discharged, and the sludge deposited at the bottom of the secondary sedimentation tank is recycled;

[0014] The first treatment mixed liquor obtained after the decomposition and ammoniation of organic nitrogen of the low-temperature wastewater in the hydrolysis acidification zone is introduced into the anaerobic zone, the sludge pumped out from the secondary sedimentation tank is synchronously introduced into the anaerobic zone through a first sludge return pipe, the first treatment mixed liquor, the synchronously introduced sludge, and the suspended biological filler added into the anaerobic zone are mixed, the enriched anaerobic ammonia oxidation bacteria under anoxic conditions convert ammonia nitrogen into nitrogen gas to achieve denitrification, the enriched denitrifying phosphorus-accumulating bacteria are converted into small-molecule volatile fatty acids (VFAs) and synthetic internal carbon source (PHA), and release phosphate to achieve denitrification and phosphorus removal, and the second treatment mixed liquor is obtained;

[0015] The third treatment mixed liquor obtained by the second treatment mixed liquor through the anoxic-aerobic variable zone is introduced into the aerobic zone to absorb phosphorus, and ammonia nitrogen is oxidized into nitrate nitrogen and nitrite nitrogen; and under a low-dissolved-oxygen condition, the embedding body in the aerobic zone enriches short-range nitrifying bacteria, strengthens denitrification and phosphorus removal under low-temperature conditions, and the fourth treatment mixed liquor is obtained;

[0016] The fourth treatment mixed liquor containing a large amount of nitrate nitrogen / nitrite nitrogen is introduced into the aerobic-anoxic variable zone, part of the nitrogen is removed by simultaneous nitrification and denitrification under an anoxic mode to obtain the fifth treatment mixed liquor, the fifth treatment mixed liquor is mixed with the sludge synchronously pumped out from the secondary sedimentation tank and introduced through a second sludge return pipe, nitrate nitrogen is converted into nitrogen gas through a long anoxic mode to achieve denitrification, and the sixth treatment mixed liquor is obtained;

[0017] The sixth treatment mixture passes through the anoxic and aerobic variable zone to form a final treatment mixture that meets discharge standards.

[0018] In combination with the first aspect, in an implementable manner, when the low-temperature wastewater is sewage under industrial wastewater stress:

[0019] The total nitrogen in the low-temperature wastewater is 50-70 mg / L, the percentage of organic nitrogen to total nitrogen is 10%-20%, the C / N ratio is 4-7, and the water temperature is <15°C.

[0020] In combination with the first aspect, in an implementable manner, the sludge reflux ratio synchronously entering the anaerobic zone is 70%-120%, and the reflux sludge concentration is 4000-5500 mg / L; the filling ratio of the suspended biological filler added in the anaerobic zone is 20%-30%.

[0021] In combination with the first aspect, in an implementable manner, the anaerobic and aerobic variable zone is operated in an aerobic mode with a dissolved oxygen of 1-4 mg / L to strengthen complete nitrification.

[0022] In combination with the first aspect, in an implementable manner, the embedding body includes polyvinyl alcohol (PVA) and sodium alginate (SA), and is fixed in the aerobic zone by silk screen after being mixed and solidified, with a filling ratio of 30%-40%.

[0023] In combination with the first aspect, in an implementable manner, the sludge synchronously entering the anoxic zone has a sludge reflux ratio of 70%-120% and a reflux sludge concentration of 4000-5500 mg / L.

[0024] In combination with the first aspect, in an implementable manner, the anaerobic and aerobic variable zone is operated in an aerobic mode with a dissolved oxygen of 1-1.5 mg / L to strengthen nitrification and deep oxidation of organic matter, so that the effluent meets the discharge standards: ammonia nitrogen <1.5 mg / L and COD <20 mg / L.

[0025] In combination with the first aspect, in an implementable manner, when the low-temperature wastewater to be treated is industrial wastewater under high total nitrogen load stress:

[0026] The total nitrogen is 70-100 mg / L, the percentage of organic nitrogen to total nitrogen is 10%-15%, the water temperature is <15°C, and the C / N ratio is 3-6;

[0027] The sludge reflux ratio synchronously entering the anaerobic zone is 100%-150%, and the reflux sludge concentration is 4000-5500 mg / L;

[0028] The anaerobic and aerobic variable zone is operated in an anaerobic mode to prolong the anaerobic zone for strengthening internal carbon source synthesis and phosphorus release;

[0029] The sludge reflux ratio synchronously entering the anoxic zone is 100% to 150%, and the concentration of the reflux sludge is 4000 to 5500 mg / L.

[0030] In combination with the first aspect, in an implementable manner, when the low-temperature wastewater is under the condition of water quantity impact, low load and low C / N ratio, the following is implemented:

[0031] The total nitrogen is 30 to 40 mg / L, the water temperature is less than 15℃, and the C / N ratio is 3 to 4;

[0032] In the anoxic zone, a small amount of external carbon source is added through an external carbon source tank connected by a carbon source adding pump, 1 mg of N is added with 1 to 3 mg of COD equivalent carbon source, and the carbon source is maintained stable; when the nitrate concentration NO3 - When N is greater than 10 mg / L and the C / N ratio is less than 5, the carbon source adding pump is started, when NO3 - When N is less than 8 mg / L, the carbon source adding pump is stopped;

[0033] The anoxic and aerobic variable zone is operated in an anoxic mode to prolong the anoxic time, enhance the activity of denitrifying bacteria, and remove nitrogen and denitrify;

[0034] According to the ammonia nitrogen concentration of the effluent of the anoxic and aerobic variable zone, the setting range of DO is adjusted: when the ammonia nitrogen concentration NH4 + N is less than 1.5 mg / L, the DO is 0.5 to 1 mg / L; when 1.5 mg / L + N is less than 8 mg / L, the DO is 1 to 1.5 mg / L; when NH4 + N is greater than 8 mg / L, the DO is 1.5 to 2 mg / L.

[0035] In the second aspect, the embodiment of the present application also provides a device for the high-organic-nitrogen low-temperature continuous-flow AOA treatment method, which comprises, in sequence, a hydrolysis acidification zone, an anaerobic zone, an anaerobic and aerobic variable zone, an aerobic zone, an aerobic and anoxic variable zone, an anoxic zone, an anoxic and aerobic variable zone and a secondary sedimentation tank; the secondary sedimentation tank is connected with the anaerobic zone through a first sludge reflux pipe and connected with the anoxic zone through a second sludge reflux pipe.

[0036] The device further comprises an external carbon source tank connected with the anoxic zone.

[0037] The high-organic-nitrogen low-temperature continuous-flow AOA treatment method and device have the beneficial effects that the wastewater treated by the method can reserve necessary internal carbon sources for subsequent anoxic denitrification, effectively alleviates the contradiction of insufficient external carbon sources, provides stable nitrite nitrogen substrate supply for anaerobic ammonia oxidation bacteria, helps to stabilize the treatment performance of the device under the double pressures of low temperature and water quality fluctuation, realizes efficient total nitrogen removal under the condition of no additional carbon source, and improves the overall low-temperature resistance; meanwhile, the addition amount of external carbon source and sludge production are reduced, and a new idea is provided for actual wastewater treatment plant upgrading and reconstruction, energy consumption reduction, and sludge production reduction. BRIEF DESCRIPTION OF DRAWINGS

[0038] Figure 1 The process flow structure schematic diagram of the high-organic-nitrogen low-temperature continuous-flow AOA treatment method is provided for the embodiments of the application.

[0039] Marked for explanation:

[0040] 1, water tank; 2, water inlet pump; 3, hydrolysis acidification zone; 4, anaerobic zone; 41, first anaerobic section; 42, second anaerobic section; 5, anaerobic-aerobic variable zone; 6, aerobic zone; 61, first aerobic section; 62, second aerobic section; 7, aerobic-anoxic variable zone; 8, anoxic zone; 81, first anoxic section; 82, second anoxic section; 83, third anoxic section; 84, fourth anoxic section; 85, fifth anoxic section; 86, sixth anoxic section; 9, anoxic-aerobic variable zone; 10, secondary sedimentation tank; 11, first sludge return pipe; 12, first sludge return pump; 13, second sludge return pipe; 14, second sludge return pump; 15, aeration head; 16, aeration pipe; 17, air blower; 18, PLC controller; 19, electric agitator; 20, online DO monitoring probe; 21, handheld dissolved oxygen instrument; 22, suspended biological filler; 23, embedding body; 24, water quality online monitoring equipment; 25, water quality online multi-parameter monitoring equipment; 26, online monitoring nitrate probe; 27, online monitoring ammonia nitrogen probe; 28, external carbon source storage tank; 29, carbon source addition pump; 30, computer; 31, sludge discharge pipe. DETAILED DESCRIPTION

[0041] In order to make the technical problems, technical solutions and beneficial effects of the present application clearer, the present application will be further described in detail below in combination with the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0042] In the claims, specification and above drawings of the present application, unless otherwise explicitly defined, the terms such as "first", "second" or "third" are used only to distinguish different objects, and are not used to describe a specific order.

[0043] In the present application, the expressions "greater than", "less than", "exceed" and the like are understood as not including the number, and the expressions "above", "below", "within" and the like are understood as including the number, in the same way as the understanding in the "Examination Guidelines". In addition, in the description of the embodiments of the present application, the meaning of "a plurality of" is two or more (including two), and similar expressions related to "a plurality of" are also understood in this way, for example, "a plurality of groups", "a plurality of times" and the like, unless otherwise explicitly and specifically limited.

[0044] For the convenience of understanding, the terms in the text are explained as follows:

[0045] Anaerobic ammonia oxidation bacteria and denitrifying phosphorus accumulating bacteria can synergize in wastewater treatment to achieve nitrogen and phosphorus removal functions. They process nitrogen and phosphorus pollutants through different metabolic pathways, and the differences in their mechanisms are as follows:

[0046] Anaerobic ammonia oxidation bacteria: under anaerobic conditions, ammonia nitrogen is directly converted into nitrogen gas using ammonia nitrogen as the electron donor and nitrite as the electron acceptor, without the participation of organic matter.

[0047] Denitrifying phosphorus accumulating bacteria: in an anaerobic / anoxic alternating environment, nitrate or nitrite is used as the electron acceptor to complete denitrification and excess phosphorus uptake, and polyhydroxyalkanoate (PHA) is used as the internal carbon source.

[0048] Chemical oxygen demand (COD) refers to the amount of oxygen consumed by the reduction of inorganic and organic substances (usually organic substances) in a water sample through chemical reactions, and is a very important indicator for judging whether the water environment is polluted.

[0049] DO value, i.e. dissolved oxygen content, refers to the concentration of molecular oxygen dissolved in water.

[0050] NH4 + -N represents the nitrogen content of ammonium ions.

[0051] Nitrifying bacteria are autotrophic aerobic bacteria, and their main function is to convert ammonia nitrogen (NH3-N) in wastewater into nitrite nitrogen (NO2 - -N), and further oxidize it into nitrate nitrogen (NO3 - -N), thereby removing ammonia nitrogen.

[0052] Please refer to Figure 1 , and the high-organic-nitrogen low-temperature continuous-flow AOA treatment method provided by the present application will be described.

[0053] The process flow of the present application is as follows: the low-temperature wastewater is sequentially treated in the hydrolysis acidification zone 3, the anaerobic zone 4, the anaerobic and aerobic variable zone 5, the aerobic zone 6, the aerobic and anoxic variable zone 7, the anoxic zone 8, and the anoxic and aerobic variable zone 9, and then the final treatment mixed liquor is formed and enters the secondary sedimentation tank 10 for sedimentation and separation, the upper clear water reaches the discharge standard and is discharged, and the sludge deposited at the bottom of the secondary sedimentation tank 10 is recycled.

[0054] In combination Figure 1 The embodiments under different conditions provided by the present application are understood.

[0055] Embodiment 1

[0056] When the low-temperature wastewater is under the stress of industrial wastewater, the treatment process is as follows:

[0057] Step 1: The wastewater under the stress of industrial wastewater has a total nitrogen of 50-70 mg / L (organic nitrogen / total nitrogen: 10%-20%) and a C / N of 4-7, and the water temperature is <15°C. The wastewater is introduced into the hydrolysis acidification zone 3 of the AOA device from the water tank 1 through the water inlet pump 2, and the organic nitrogen is decomposed and ammoniated to obtain a first treatment mixed liquor.

[0058] The first treatment mixed liquor enters the anaerobic zone 4, the sludge extracted from the secondary sedimentation tank 10 by the first sludge return pump 12 enters the anaerobic zone 4 through the first sludge return pipe 11 at the same time, and the first treatment mixed liquor, the sludge added at the same time, and the suspended biological filler 22 added to the anaerobic zone 4 are stirred and mixed by the electric stirrer 19 inserted therein. The purpose of adding the suspended biological filler 22 is to provide a carrier for the growth of the bacterial flora, and at the same time, to create conditions for the enrichment of anaerobic ammonia oxidation bacteria by using the internal anoxic structure. The enriched denitrifying phosphorus bacteria absorb small-molecule volatile fatty acids (VFAs) in the anaerobic zone 4, synthesize internal carbon source PHA, release phosphate, achieve denitrification and phosphorus removal, and obtain a second treatment mixed liquor.

[0059] Among them, the sludge return ratio is 70%-120%, the return sludge concentration is 4000-5500 mg / L, and the filling ratio of the suspended biological filler 22 added to the anaerobic zone 4 is 20%-30%.

[0060] Step 2: The second treatment mixed liquor enters the anaerobic and aerobic variable zone 5, which is operated in an aerobic mode with a dissolved oxygen of 1-4 mg / L, and is stirred and mixed by the electric stirrer 19 inserted therein to strengthen complete nitrification, and a third treatment mixed liquor is obtained.

[0061] When the third treatment mixed liquor enters the aerobic zone 6, the embedding body 23 is added, which is fixed in the aerobic zone 6 by a wire mesh, and the purpose is to limit the embedding body 23 to a certain range, which can effectively prevent clogging and loss of bacterial cells and improve the impact resistance.

[0062] The main function of this aerobic zone 6 is to oxidize ammonia nitrogen into nitrite nitrogen and nitrate nitrogen, and to absorb phosphorus, to obtain the fourth treatment mixed liquor. The dissolved oxygen in the aerobic zone 6 is controlled in the range of 0.5-1.5 mg / L, the water temperature is less than 15℃, the anaerobic-aerobic variable zone is operated in the aerobic mode by adjusting and controlling, the volume operated in the aerobic mode is increased, the high-efficiency short-cut nitrification sludge embedding body 23 is added, and the stable ammonia oxidation efficiency and certain short-cut nitrification effect are maintained under the condition of low dissolved oxygen and low temperature.

[0063] The embedding body 23 includes polyvinyl alcohol PVA and sodium alginate SA, which are dissolved and mixed after heating and stirring, the short-cut nitrification sludge is embedded in the embedding body 23, the obtained mixed liquor is dropped into a crosslinking agent, and is gelled by physical and chemical methods to form the spherical, granular or block-shaped immobilized embedding body 23, the density of which is 1-1.2 g / cm3; the filling ratio of the embedding body 23 as the filler is 30%-40%, and the mass ratio of the short-cut nitrification sludge to the embedding body 23 is 20%-30%.

[0064] Step 3: The fourth treatment mixed liquor containing a large amount of nitrate nitrogen / nitrite nitrogen enters the aerobic-anoxic variable zone 7, the aerobic-anoxic variable zone 7 is operated in the anoxic mode, part of the nitrogen is removed through simultaneous nitrification and denitrification, and the fifth treatment mixed liquor is obtained.

[0065] The fifth treatment mixed liquor enters the anoxic zone 8, the sludge taken out from the secondary sedimentation tank 10 by the second sludge return pump 14 enters the anoxic zone 8 through the second sludge return pipe 13, is stirred and mixed by the electric agitator 19 extending into the anoxic zone 8, and is subjected to long anoxia to convert the nitrate nitrogen into nitrogen gas, so as to perform denitrification, and the sixth treatment mixed liquor is obtained.

[0066] The total hydraulic retention time of the aerobic-anoxic variable zone 7 and the anoxic zone 8 is 6.5-8.2 h, and the sludge return ratio is 70%-120%, and the return sludge concentration is 4000-5500 mg / L.

[0067] The residual sludge in the secondary sedimentation tank 10 is discharged from the sludge discharge pipe 31.

[0068] Step 4: The sixth treatment mixed liquor enters the anoxic-aerobic variable zone 9, the anoxic-aerobic variable zone 9 is operated in the aerobic mode, and the dissolved oxygen is set to 1-1.5 mg / L; the main function of this anoxic-aerobic variable zone 9 is to further strengthen nitrification and deeply oxidize organic matter, and the final treatment mixed liquor is obtained.

[0069] The final treatment mixed liquor enters the secondary sedimentation tank 10 for sedimentation, the effluent ammonia nitrogen of the obtained upper clear water is less than 1.5 mg / L, and the COD is less than 20 mg / L, so that the discharge standard is achieved.

[0070] Step 5, water tank 1, aerobic zone 6, anoxic zone 8, and anoxic-aerobic variable zone 9 are provided with water quality online monitoring equipment 24, which can feed the COD, ammonia nitrogen, total nitrogen, and total phosphorus indicators to the computer 30 in real time. The aerobic zone 6 and the anoxic-aerobic variable zone 9 are provided with online DO monitoring probes 20 and are connected to handheld dissolved oxygen meters 21. Real-time signals are fed to the computer 30. When the DO value is lower than the set lower limit, the air blower 17 is turned on, and the aeration pipe 16 is used to blow air to the aeration heads 15 in the anaerobic-aerobic variable zone 5, the aerobic zone 6, the aerobic-anoxic variable zone 7, and the anoxic-aerobic variable zone 9 to increase the DO value. When the DO value is higher than the set upper limit, the air blower 17 is turned off.

[0071] Example 1 is a stable operation state under industrial wastewater stress and low temperature conditions. By adding a hydrolysis acidification section and shortening the hydraulic retention time in the anaerobic section (hydraulic retention time of 1.5-2.5 h), the conversion of macromolecular organic matter into small molecular organic matter is ensured under the premise of minimizing carbon source consumption, which guarantees the efficient synthesis of internal carbon source PHA in the anaerobic section and ammoniation of organic nitrogen. The anaerobic-aerobic variable zone 5 is adjusted to operate in aerobic mode, and short-cut nitrification sludge inclusions 23 are added to the aerobic zone 6, which can improve the ammonia oxidation efficiency of the system and achieve a nitrite accumulation rate of more than 60%. The anoxic section relies on internal carbon sources and stored substances to drive denitrification, using nitrite nitrogen as an electron acceptor. Under the condition of limited carbon source, stable denitrification performance can still be maintained without the need for external carbon source.

[0072] This mode adjusts the proportion of each stage and adds inclusions 23 to increase the concentration of functional bacteria, which can effectively cope with the adverse effects of low temperature and low ammonia oxidation efficiency, and can achieve efficient conversion of organic nitrogen and deep removal of total nitrogen, providing a reliable technical path for low-temperature, low-carbon-nitrogen-ratio, and high-organic-nitrogen-ratio wastewater.

[0073] Example 2

[0074] When the industrial wastewater is under high total nitrogen load conditions:

[0075] Step 1, when the water quality fluctuates greatly, the total nitrogen is 70-100 mg / L (organic nitrogen / total nitrogen: 10%-15%), the water temperature is <15°C, and the C / N is 3-6. The total nitrogen is higher than that in Example 1, and the carbon-nitrogen ratio is lower than that in Example 1.

[0076] The same as Step 1 of Example 1 in Step 1 of Example 2 is that the organic nitrogen is decomposed and ammoniated in the hydrolysis acidification zone 3, and then enters the anaerobic zone 4, and the sludge at the end of the secondary sedimentation tank 10 is also introduced.

[0077] Different from step 1 of example 1: sludge reflux ratio 100%~150%, reflux sludge concentration 4000~5500mg / L, mixed by electric agitator 19, denitrifying phosphorus accumulating organisms in anaerobic zone 4 synthesize small molecule volatile fatty acids VFAs into internal carbon source PHA, release phosphate.

[0078] Step 2, different from step 2 of example 1: anaerobic and aerobic variable zone 5 runs in anaerobic mode, prolongs anaerobic mode, and strengthens internal carbon source synthesis and phosphorus release.

[0079] Step 3, different from step 3 of example 1: the fourth treatment mixed liquor containing a large amount of nitrate nitrogen / nitrite nitrogen enters the aerobic and anoxic variable zone 7, and the aerobic and anoxic variable zone 7 runs in aerobic mode.

[0080] Anoxic zone 8 synchronously enters the sludge drawn from the second sludge reflux pump 14 from the secondary sedimentation tank 10, and different from example 1: sludge reflux ratio 100%~150% (higher than example 1), reflux sludge concentration 4000~5500mg / L, mixed by electric agitator 19 and converted into nitrogen gas from nitrate nitrogen through long anoxic, thereby denitrifying. The residence time in anoxic zone 8 is 5.5~7.2h.

[0081] Step 4, same as step 4 of example 1.

[0082] Step 5, same as step 5 of example 1.

[0083] Example 2 is the operation under the conditions of low temperature, high organic nitrogen ratio, and high total nitrogen load stress of industrial wastewater. The organic matter in the influent will be adsorbed by the sludge in the anaerobic zone 4 and converted into internal carbon source. Under the condition of high total nitrogen load, by prolonging the hydraulic retention time of the anaerobic section (the hydraulic retention time is 2~3.5h), improving the sludge reflux ratio, adding the filler in the anaerobic zone 4, and adding the short-range sludge embedding body 23 in the aerobic zone 6, the short-range nitrification in the aerobic zone 6 can be stabilized and the effect of anaerobic ammonia oxidation in the anaerobic zone 4 can be achieved, realizing the total nitrogen removal in the anaerobic zone 4. This strategy promotes the internal storage (such as PHA) of microorganisms such as phosphorus accumulating bacteria and glycogen bacteria in the anaerobic environment, reserves the necessary internal carbon source for subsequent anoxic denitrification, effectively alleviates the contradiction of insufficient external carbon source, and provides stable nitrite nitrogen substrate for anaerobic ammonia oxidation bacteria.

[0084] Under the double pressure of low temperature and water quality fluctuation, this operation adjustment helps to stabilize the system performance and achieve efficient total nitrogen removal without additional carbon source.

[0085] Example 3

[0086] Low temperature wastewater under the conditions of low load, low C / N ratio, and water quantity impact:

[0087] Step 1, when water impact conditions such as heavy rain occur, total nitrogen is about 30-40 mg / L, temperature <15℃, C / N is about 3-4 (lower than examples 1, 2, low temperature and low carbon-nitrogen ratio conditions), and the rest is the same as step 1 of example 1.

[0088] Step 2, the same as step 2 of example 1.

[0089] Step 3, the difference from step 3 of example 1 is that:

[0090] A small amount of external carbon source needs to be added by connecting the external carbon source tank 28 through the carbon source adding pump 29 in the anoxic zone 8, the type is composite carbon source, 1 mgN adds 1-3 mgCOD equivalent carbon source, to avoid the decrease of treatment efficiency due to insufficient carbon source and maintain the stability of the system.

[0091] The nitrate concentration fed back by the water quality online multi-parameter monitoring equipment 25 connected with the online monitoring nitrate probe 26 arranged in the anoxic zone 8 is set as follows: - When NO3 - When NO3

[0092] Step 4, the difference from step 4 of example 1 is that:

[0093] The anoxic and aerobic variable zone 9 is operated in anoxic mode, the anoxic time is prolonged, the activity of denitrifying bacteria is enhanced, and the core function is to realize denitrification and remove nitrogen elements in wastewater.

[0094] Step 5, the difference from step 5 of example 1 is that:

[0095] According to the ammonia nitrogen concentration of the effluent of the anoxic and aerobic variable zone 9 fed back by the computer 30, the setting range of DO is adjusted accordingly:

[0096] When the ammonia nitrogen concentration NH4 + When NH4 + When NH4 + When NH4

[0097] Example 3 is a water quantity impact low load low C / N ratio condition, the system will face the double challenge of absolute shortage of carbon source and decline of reaction driving force. Combined with online device data acquisition and model calculation, the operation strategy of prolonging the hydraulic retention time of the anoxic section (the hydraulic retention time is 6-8h) and supplementing with precise addition of external carbon source can effectively guarantee the thoroughness of denitrification, make up for the structural shortage of carbon source, and maintain the microbial activity and system stability to cope with the sudden situation of water quality stability and standard reaching.

[0098] In the above examples, the description of each example has its own focus, and the parts not described or recorded in a certain example can be referred to the related description of other examples.

[0099] Figure 1 The structural diagram of the device provided by the application is based on the same inventive concept, and the device provided by the embodiment of the application is also provided for the AOA method for treating high-organic-nitrogen low-temperature continuous flow based on short-range nitrifying bacteria embedding body 23, which comprises: a hydrolysis acidification zone 3, an anaerobic zone 4, an anaerobic-aerobic variable zone 5, an aerobic zone 6, an aerobic-anoxic variable zone 7, an anoxic zone 8, an anoxic-aerobic variable zone 9 and a secondary sedimentation tank 10 connected in sequence. The secondary sedimentation tank 10 is connected with the anaerobic zone 4 through a first sludge return pipe 11 and connected with the anoxic zone 8 through a second sludge return pipe 13; a first sludge return pump 12 is arranged on the first sludge return pipe 11, and a second sludge return pump 14 is arranged on the second sludge return pipe 13.

[0100] The device also comprises an external carbon source storage tank 28, a water tank 1, a blower 17 and an electric stirrer 19. The external carbon source storage tank 28 is connected with the anoxic zone 8, and a carbon source adding pump 29 is arranged on the pipeline between the external carbon source storage tank 28 and the anoxic zone 8; the water tank 1 is connected with the hydrolysis acidification zone 3 through a water inlet pump 2. The electric stirrer 19 is arranged in the hydrolysis acidification zone 3, the anaerobic zone 4, the anaerobic-aerobic variable zone 5, the aerobic zone 6, the aerobic-anoxic variable zone 7, the anoxic zone 8 and the anoxic-aerobic variable zone 9.

[0101] The blower 17 is connected with the aeration head 15 in the anaerobic-aerobic variable zone 5, the aerobic zone 6, the aerobic-anoxic variable zone 7, the anoxic zone 8 and the anoxic-aerobic variable zone 9 through the aeration pipe 16.

[0102] The suspended biological filler 22 is placed in the anaerobic zone 4, and the embedding body 23 is placed in the aerobic zone 6.

[0103] According to the process flow, the anaerobic zone 4 is divided into a first anaerobic section 41 and a second anaerobic section 42; the suspended biological filler 22 and the electric stirrer 19 are arranged in each anaerobic section.

[0104] The aerobic zone 6 is divided into a first aerobic section 61 and a second aerobic section 62 according to the technological process, and the embedded body 23, the electric agitator 19 and the aeration head 15 are arranged in each aerobic section.

[0105] The anoxic zone 8 is divided into a first anoxic section 81, a second anoxic section 82, a third anoxic section 83, a fourth anoxic section 84, a fifth anoxic section 85 and a sixth anoxic section 86 according to the technological process, and the electric agitator 19 and the aeration head 15 are arranged in each anoxic section.

[0106] The device further comprises a computer 30, a PLC controller 18, an online water quality multi-parameter monitoring device 25, an online monitoring nitrate probe 26, an online DO monitoring probe 20, an online monitoring ammonia nitrogen probe 27 and a handheld dissolved oxygen meter 21 connected through an electrical circuit.

[0107] The online monitoring nitrate probe 26 arranged in the anoxic zone 8 is connected with the online water quality multi-parameter monitoring device 25, and the real-time data fed back by the computer 30 is used to start the carbon source adding pump 29 to add carbon source.

[0108] The online DO monitoring probe 20 arranged in the aerobic zone 6 and the anoxic and aerobic variable zone 9 is connected with the handheld dissolved oxygen meter 21, and the online monitoring ammonia nitrogen probe 27 is connected with the online water quality multi-parameter monitoring device 25, and the real-time signal is fed back to the computer 30.

[0109] The water tank 1 is provided with an online water quality monitoring device 24, and the computer 30 is connected with the PLC controller 18 to adjust the air volume of the air blower 17.

[0110] The above only describes the preferred embodiments of the present application and is not used to limit the present application, and any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for treating high-organic-nitrogen, low-temperature, continuous-flow AOA (autoclave-associated oxygen) systems, characterized in that, The method includes: The low-temperature wastewater is sequentially treated through the hydrolysis acidification zone (3), anaerobic zone (4), anaerobic-aerobic variable zone (5), aerobic zone (6), aerobic-anoxic variable zone (7), anoxic zone (8), and anoxic-aerobic variable zone (9) to form the final treated mixture, which enters the secondary sedimentation tank (10) for sedimentation and separation. The upper clarified water meets the discharge standards and is discharged, while the sludge deposited at the bottom of the secondary sedimentation tank (10) is reused. The first treatment mixture obtained after the low-temperature wastewater undergoes organic nitrogen decomposition and ammoniation in the hydrolysis acidification zone (3) enters the anaerobic zone (4). The sludge pumped out from the secondary sedimentation tank (10) enters the anaerobic zone (4) simultaneously through the first sludge return pipe (11). The first treatment mixture, the sludge entering simultaneously, and the suspended biological packing material (22) added to the anaerobic zone (4) are mixed. Under anoxic conditions, the anaerobic ammonia-oxidizing bacteria enriched convert ammonia nitrogen into nitrogen gas to achieve denitrification. The enriched denitrifying polyphosphate bacteria convert into small molecule volatile fatty acids (VFAs) and synthesize internal carbon source (PHA), releasing phosphate to achieve denitrification and phosphorus removal, and obtain the second treatment mixture. The second treatment mixture, after passing through the anaerobic-aerobic variable zone (5), is used to obtain the third treatment mixture, which then enters the aerobic zone (6) to absorb phosphorus. At the same time, ammonia nitrogen is oxidized into nitrite nitrogen and nitrate nitrogen. Under low dissolved oxygen conditions, short-range nitrifying and denitrifying bacteria are enriched through the embedded body (23) in the aerobic zone (6) to enhance nitrogen and phosphorus removal under low temperature conditions, thereby obtaining the fourth treatment mixture. The fourth treatment mixture containing a large amount of nitrate nitrogen / nitrite nitrogen enters the aerobic-anoxic variable zone (7) to obtain the fifth treatment mixture. It is then mixed with sludge that is simultaneously drawn from the secondary sedimentation tank (10) and enters through the second sludge return pipe (13) in the anoxic zone (8). The nitrate nitrogen is converted into nitrogen gas through the long anoxic mode to achieve denitrification and obtain the sixth treatment mixture. The sixth treatment mixture passes through the anoxic-aerobic variable zone (9), and the final treatment mixture formed meets the emission standards. When the low-temperature wastewater is wastewater under industrial wastewater stress: The total nitrogen in the low-temperature wastewater is 50-70 mg / L, the percentage of organic nitrogen to total nitrogen is 10%-20%, the C / N ratio is 4-7, and the water temperature is <15℃; The sludge return ratio entering the anaerobic zone (4) simultaneously is 70%~120%, and the return sludge concentration is 4000~5500 mg / L; the filling ratio of the suspended biological packing material (22) added to the anaerobic zone (4) is 20%~30%; The anaerobic-aerobic variable zone (5) operates in aerobic mode with dissolved oxygen of 1~4 mg / L to enhance complete nitrification; The fourth treatment mixture containing a large amount of nitrate nitrogen / nitrite nitrogen enters the aerobic-anoxic variable zone (7), which operates in anoxic mode. Some nitrogen is removed through simultaneous nitrification and denitrification to obtain the fifth treatment mixture. The sludge that enters the anoxic zone (8) simultaneously has a sludge return ratio of 70% to 120% and a return sludge concentration of 4000 to 5500 mg / L. The anoxic-aerobic variable zone (9) operates in aerobic mode with dissolved oxygen set at 1~1.5 mg / L to enhance nitrification and deep oxidation of organic matter, achieving the effluent discharge standards: ammonia nitrogen <1.5 mg / L, COD <20 mg / L.

2. The high-organic-nitrogen, low-temperature, continuous-flow AOA treatment method as described in claim 1, characterized in that, The embedded body (23) includes polyvinyl alcohol (PVA) and sodium alginate (SA), which are mixed and cured and then fixed in the aerobic zone (6) by wire mesh, with a filling ratio of 30% to 40%.

3. A method for treating high-organic-nitrogen, low-temperature, continuous-flow AOA (autoclave-associated oxygen) systems, characterized in that: The method includes: The low-temperature wastewater is sequentially treated through the hydrolysis acidification zone (3), anaerobic zone (4), anaerobic-aerobic variable zone (5), aerobic zone (6), aerobic-anoxic variable zone (7), anoxic zone (8), and anoxic-aerobic variable zone (9) to form the final treated mixture, which enters the secondary sedimentation tank (10) for sedimentation and separation. The upper clarified water meets the discharge standards and is discharged, while the sludge deposited at the bottom of the secondary sedimentation tank (10) is reused. The first treatment mixture obtained after the low-temperature wastewater undergoes organic nitrogen decomposition and ammoniation in the hydrolysis acidification zone (3) enters the anaerobic zone (4). The sludge pumped out from the secondary sedimentation tank (10) enters the anaerobic zone (4) simultaneously through the first sludge return pipe (11). The first treatment mixture, the sludge entering simultaneously, and the suspended biological packing material (22) added to the anaerobic zone (4) are mixed. Under anoxic conditions, the anaerobic ammonia-oxidizing bacteria enriched convert ammonia nitrogen into nitrogen gas to achieve denitrification. The enriched denitrifying polyphosphate bacteria convert into small molecule volatile fatty acids (VFAs) and synthesize internal carbon source (PHA), releasing phosphate to achieve denitrification and phosphorus removal, and obtain the second treatment mixture. The second treatment mixture, after passing through the anaerobic-aerobic variable zone (5), is used to obtain the third treatment mixture, which then enters the aerobic zone (6) to absorb phosphorus. At the same time, ammonia nitrogen is oxidized into nitrite nitrogen and nitrate nitrogen. Under low dissolved oxygen conditions, short-range nitrifying and denitrifying bacteria are enriched through the embedded body (23) in the aerobic zone (6) to enhance nitrogen and phosphorus removal under low temperature conditions, thereby obtaining the fourth treatment mixture. The fourth treatment mixture containing a large amount of nitrate nitrogen / nitrite nitrogen enters the aerobic-anoxic variable zone (7) to obtain the fifth treatment mixture. It is then mixed with sludge that is simultaneously drawn from the secondary sedimentation tank (10) and enters through the second sludge return pipe (13) in the anoxic zone (8). The nitrate nitrogen is converted into nitrogen gas through the long anoxic mode to achieve denitrification and obtain the sixth treatment mixture. The sixth treatment mixture passes through the anoxic-aerobic variable zone (9), and the final treatment mixture formed meets the emission standards. When the treated low-temperature wastewater is industrial wastewater under stress with a high total nitrogen load: Total nitrogen is 70~100 mg / L, organic nitrogen / total nitrogen percentage is 10%~15%, water temperature is <15℃, C / N ratio is 3~6; The sludge return ratio that enters the anaerobic zone (4) simultaneously is 100%~150%, and the concentration of the returned sludge is 4000~5500 mg / L; The anaerobic-aerobic variable zone (5) operates in anaerobic mode, extending the anaerobic zone (4) to enhance the synthesis of internal carbon sources and phosphorus release; The fourth treatment mixture containing a large amount of nitrate nitrogen / nitrite nitrogen enters the aerobic-anoxic variable zone (7), which operates in aerobic mode; The sludge return ratio that enters the anoxic zone (8) simultaneously is 100%~150%, and the concentration of the returned sludge is 4000~5500 mg / L; The anoxic-aerobic variable zone (9) operates in aerobic mode with dissolved oxygen set at 1~1.5 mg / L to enhance nitrification and deep oxidation of organic matter, achieving the effluent discharge standards: ammonia nitrogen <1.5 mg / L, COD <20 mg / L.

4. A method for treating high-organic-nitrogen, low-temperature, continuous-flow AOA (autoclave-associated oxygen) systems, characterized in that, The method includes: The low-temperature wastewater is sequentially treated through the hydrolysis acidification zone (3), anaerobic zone (4), anaerobic-aerobic variable zone (5), aerobic zone (6), aerobic-anoxic variable zone (7), anoxic zone (8), and anoxic-aerobic variable zone (9) to form the final treated mixture, which enters the secondary sedimentation tank (10) for sedimentation and separation. The upper clarified water meets the discharge standards and is discharged, while the sludge deposited at the bottom of the secondary sedimentation tank (10) is reused. The first treatment mixture obtained after the low-temperature wastewater undergoes organic nitrogen decomposition and ammoniation in the hydrolysis acidification zone (3) enters the anaerobic zone (4). The sludge pumped out from the secondary sedimentation tank (10) enters the anaerobic zone (4) simultaneously through the first sludge return pipe (11). The first treatment mixture, the sludge entering simultaneously, and the suspended biological packing material (22) added to the anaerobic zone (4) are mixed. Under anoxic conditions, the anaerobic ammonia-oxidizing bacteria enriched convert ammonia nitrogen into nitrogen gas to achieve denitrification. The enriched denitrifying polyphosphate bacteria convert into small molecule volatile fatty acids (VFAs) and synthesize internal carbon source (PHA), releasing phosphate to achieve denitrification and phosphorus removal, and obtain the second treatment mixture. The second treatment mixture, after passing through the anaerobic-aerobic variable zone (5), is used to obtain the third treatment mixture, which then enters the aerobic zone (6) to absorb phosphorus. At the same time, ammonia nitrogen is oxidized into nitrite nitrogen and nitrate nitrogen. Under low dissolved oxygen conditions, short-range nitrifying and denitrifying bacteria are enriched through the embedded body (23) in the aerobic zone (6) to enhance nitrogen and phosphorus removal under low temperature conditions, thereby obtaining the fourth treatment mixture. The fourth treatment mixture containing a large amount of nitrate nitrogen / nitrite nitrogen enters the aerobic-anoxic variable zone (7) to obtain the fifth treatment mixture. It is then mixed with sludge that is simultaneously drawn from the secondary sedimentation tank (10) and enters through the second sludge return pipe (13) in the anoxic zone (8). The nitrate nitrogen is converted into nitrogen gas through the long anoxic mode to achieve denitrification and obtain the sixth treatment mixture. The sixth treatment mixture passes through the anoxic-aerobic variable zone (9), and the final treatment mixture formed meets the emission standards. When low-temperature wastewater is subjected to low-volume shock, low-load, and low C / N ratio conditions: Total nitrogen is 30-40 mg / L, water temperature is <15℃, and C / N ratio is 3-4; The sludge return ratio entering the anaerobic zone (4) simultaneously is 70%~120%, and the return sludge concentration is 4000~5500 mg / L; the filling ratio of the suspended biological packing material (22) added to the anaerobic zone (4) is 20%~30%; The anaerobic-aerobic variable zone (5) operates in aerobic mode with dissolved oxygen of 1~4 mg / L to enhance complete nitrification; The fourth treatment mixture containing a large amount of nitrate nitrogen / nitrite nitrogen enters the aerobic-anoxic variable zone (7), which operates in anoxic mode. Some nitrogen is removed through simultaneous nitrification and denitrification to obtain the fifth treatment mixture. The sludge that enters the anoxic zone (8) simultaneously has a sludge return ratio of 70% to 120% and a return sludge concentration of 4000 to 5500 mg / L. In the anoxic zone (8), a small amount of external carbon source is added through an external carbon source storage tank (28) connected to a carbon source addition pump (29). For every 1 mg of N, 1-3 mg of COD equivalent carbon source is added to maintain carbon source stability. When the nitrate concentration is NO3... - The carbon source dosing pump (29) is started when NO3 > 10 mg / L and C / N < 5. - The carbon source dosing pump is turned off when -N < 8 mg / L (29); The hypoxic-aerobic variable zone (9) operates in hypoxic mode to prolong the hypoxic time, enhance the activity of denitrifying bacteria, and remove nitrogen. Based on the effluent ammonia nitrogen concentration in the anoxic-aerobic variable zone (9), adjust the DO setting range: when the ammonia nitrogen concentration NH4 + -N < 1.5 mg / L, DO is 0.5~1 mg / L; when 1.5 mg / L < NH4 + -N < 8 mg / L, DO 1~1.5 mg / L; when NH4 + -N > 8 mg / L, DO is 1.5~2 mg / L.

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