A device and method for in-situ fermentation of excess sludge to drive anaerobic ammonia oxidation self-enrichment

Abstract

The application discloses a kind of residual sludge in situ fermentation driven anaerobic ammonia oxidation self-enrichment device and method, the device includes raw water tank, whole course nitrification reactor, intermediate water tank, reactor sludge fermentation driven short-cut denitrification simultaneous anaerobic ammonia oxidation reactor, effluent bucket.The application uses the above-mentioned residual sludge in situ fermentation driven anaerobic ammonia oxidation self-enrichment device and method, and carbon source generated by residual sludge fermentation is used as electron donor to drive short-cut denitrification / anaerobic ammonia oxidation reaction, realizes residual sludge resource under the condition that no additional carbon source is needed, and utilizes sponge filler as carrier to carry out in situ self-enrichment of anaerobic ammonia oxidation bacteria, constructs integrated sludge fermentation simultaneous short-cut denitrification / anaerobic ammonia oxidation system, can provide a solution for deep denitrification of urban sewage and sludge reduction, and has important significance for realizing sustainable urban domestic sewage treatment.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of excess sludge biochemical treatment and biological nitrogen removal treatment of sewage, and particularly relates to an in-situ fermentation driven anaerobic ammonia oxidation self-enrichment device and method for excess sludge. BACKGROUND

[0002] Traditional sewage denitrification has the disadvantages of large sludge yield and high energy consumption, and the low C / N ratio characteristics of municipal sewage also make the biological denitrification performance unstable. Anaerobic ammonia oxidation can produce nitrogen gas (N2) and nitrate (NO3 + -N) under anaerobic conditions, using ammonia nitrogen (NH4 - -N) as the electron donor and nitrite (NO2 - -N) as the electron acceptor for biological denitrification reaction, and is considered to be a promising autotrophic denitrification strategy due to its low energy consumption and no need for organic carbon source. However, the slow natural enrichment rate of anaerobic ammonia oxidation bacteria due to their low growth rate and the volatility of municipal sewage hinders the large-scale application in mainstream anaerobic ammonia oxidation technology.

[0003] Continuous NO2 - -N supply is the key to the application of anaerobic ammonia oxidation in municipal sewage treatment. At present, there are two ways to obtain NO2 - -N substrate for anaerobic ammonia oxidation process: short-cut nitrification (NH4 + -N→NO2 - -N) and short-cut denitrification (NO3 - -N→NO2 - -N). In recent decades, the research on short-cut nitrification coupled with anaerobic ammonia oxidation has mainly focused on mainstream wastewater treatment. In order to further reduce the nitrate concentration of effluent, short-cut denitrification coupled with anaerobic ammonia oxidation is proposed, which can further reduce organic matter and oxygen demand without NOB elutriation. In addition, sludge fermentation can degrade sludge macromolecules into small molecules, and the short-chain fatty acids produced can drive the short-cut denitrification process as a carbon source, and the released NH4 + -N can act as a substrate for anaerobic ammonia oxidation. The combination of sludge fermentation and short-cut denitrification coupled with anaerobic ammonia oxidation can improve the stability of the anaerobic ammonia oxidation process and achieve efficient removal of total nitrogen (TIN) and sludge reduction.

[0004] Due to the low abundance of anaerobic ammonia oxidation bacteria in sludge, in order to accelerate the start-up of autotrophic denitrification system, part of the anaerobic ammonia oxidation sludge is usually inoculated in the reaction system. Therefore, the investment and operation complexity will be increased to some extent in actual application. In contrast, in-situ self-enrichment of anaerobic ammonia oxidation bacteria will be a more practical and effective stable operation strategy. Through long-term and stable supply of NH4 + -N and NO2 -The supply of N and the supplement of fillers as growth carriers will help the self-enrichment process of anaerobic ammonia oxidation bacteria. Therefore, there is a need to develop a device and method for driving anaerobic ammonia oxidation self-enrichment by in-situ fermentation of residual sludge, which can effectively solve the above problems. SUMMARY

[0005] The present application aims to provide a device and method for driving anaerobic ammonia oxidation self-enrichment by in-situ fermentation of residual sludge, which uses the carbon source produced by fermentation of residual sludge as an electron donor to drive short-term denitrification / anaerobic ammonia oxidation reaction, realizes the resource utilization of residual sludge without the need for external carbon source, and uses sponge fillers as carriers for in-situ self-enrichment of anaerobic ammonia oxidation bacteria, thereby constructing an integrated sludge fermentation synchronous short-term denitrification / anaerobic ammonia oxidation system, which can provide a solution for deep denitrification of municipal wastewater and sludge reduction, and has important significance for realizing sustainable urban domestic wastewater treatment.

[0006] To achieve the above-mentioned purpose, the present application provides a device for driving anaerobic ammonia oxidation self-enrichment by in-situ fermentation of residual sludge, which comprises a raw water tank, a full-scale nitrification reactor, an intermediate water tank, a sludge fermentation driven short-term denitrification synchronous anaerobic ammonia oxidation reactor, and a water outlet bucket. The raw water tank, the full-scale nitrification reactor, the intermediate water tank, the sludge fermentation driven short-term denitrification synchronous anaerobic ammonia oxidation reactor, and the water outlet bucket are connected by a raw water tank water inlet pump, a full-scale nitrification reactor water outlet pump, an intermediate water tank water outlet pump, and a reactor water outlet pump, respectively.

[0007] Preferably, the full-scale nitrification reactor is open, has a first water inlet at the top end of the side close to the raw water tank, has a full-scale nitrification reactor sludge discharge port at the bottom end of the side close to the raw water tank, and has a first water outlet at the middle of the side close to the intermediate water tank.

[0008] The first water inlet is connected to the output end of the raw water tank water inlet pump, and the first water outlet is connected to the input end of the full-scale nitrification reactor water outlet pump. The full-scale nitrification reactor sludge discharge port is connected to a sludge storage bucket through a full-scale nitrification reactor sludge discharge pump.

[0009] Preferably, the first water inlet and the first water outlet in the full-scale nitrification reactor are respectively provided with a first pH monitor and a dissolved oxygen monitor. The top end of the inside of the full-scale nitrification reactor is provided with a first stirrer, and the bottom end of the inside of the full-scale nitrification reactor is provided with an aeration disc.

[0010] Preferably, the intermediate water tank has a second water inlet at the middle of the side close to the full-scale nitrification reactor, and the second water inlet is connected to the output end of the full-scale nitrification reactor water outlet pump. The intermediate water tank has a second water outlet at the bottom of the side close to the reactor, and the second water outlet is connected to the input end of the intermediate water tank water outlet pump.

[0011] Preferably, the sludge fermentation driven short-cut denitrification and ANAMMOX reactor is a double-layer structure, the outer layer is provided with a water bath heating rod, and the inner layer is provided with a top cover, and the sludge fermentation driven short-cut denitrification and ANAMMOX reactor is provided with a second stirrer inside the top cover; the inner layer of the sludge fermentation driven short-cut denitrification and ANAMMOX reactor is provided with a plurality of sponge filler racks at the bottom.

[0012] Preferably, the inner layer of the sludge fermentation driven short-cut denitrification and ANAMMOX reactor is provided with a third water inlet at the top of the side close to the intermediate water tank, and the third water inlet is connected with the output end of the water outlet pump of the intermediate water tank.

[0013] The inner layer of the sludge fermentation driven short-cut denitrification and ANAMMOX reactor is provided with a reactor sludge discharge port at the bottom of the side close to the intermediate water tank, and the reactor sludge discharge port is connected with the sludge discharge barrel through a reactor sludge discharge pump.

[0014] Preferably, the inner layer of the sludge fermentation driven short-cut denitrification and ANAMMOX reactor is provided with a sludge inlet at the top of the side close to the water outlet barrel, and the sludge inlet is connected with the sludge storage barrel through a sludge inlet pump.

[0015] The inner layer of the sludge fermentation driven short-cut denitrification and ANAMMOX reactor is provided with a third water outlet at the middle of the side close to the water outlet barrel, and the third water outlet is connected with the input end of the reactor water outlet pump.

[0016] The second pH monitor and the ORP monitor are respectively arranged at the bottom of the third water inlet and the sludge inlet of the inner layer of the sludge fermentation driven short-cut denitrification and ANAMMOX reactor.

[0017] A method for in-situ fermentation of excess sludge to drive ANAMMOX self-enrichment, comprising the following steps:

[0018] Step S1, starting and stabilizing the full-scale nitrification reactor;

[0019] Step S11, using municipal domestic sewage as raw water, wherein the ammonia nitrogen concentration is 30-60 mg / L, and the raw water is injected into the full-scale nitrification reactor through a raw water pump;

[0020] Step S12, inoculating activated sludge from the aeration tank of a municipal sewage treatment plant into the full-scale nitrification reactor, controlling the sludge concentration after mixing to be 2000-5000 mg / L, and regularly discharging sludge to the sludge storage barrel to control the sludge age to be 15-25 days;

[0021] Wherein, each operation cycle of the full-scale nitrification reactor is 4-8 h, and there are 3-6 cycles per day, including: water inlet for 10-15 min, anoxic stirring for 1-2 h, aerobic aeration for 3-4 h, dissolved oxygen control at 2-3 mg / L, pH value maintained at 6.5-8.5, sedimentation for 30 min, and water discharge for 5-10 min, and the water discharge ratio is 50%-70%;

[0022] Step S13, when the ammonia nitrogen of raw water is converted into nitrate nitrogen at a rate of 95% or more and can be stably maintained for 7 days or more, the full-scale nitrification reactor is stably operated;

[0023] Step S2, start-up of sludge in-situ fermentation driving short-cut denitrification;

[0024] Step S3, realization of anammox bacteria self-enrichment.

[0025] Preferably, step S2 is specifically,

[0026] Step S21, during the operation of the sludge fermentation driving short-cut denitrification and anammox reactor, the water bath heating is always maintained at 35±2℃, and the pH is 8.5-9.0;

[0027] The sludge fermentation driving short-cut denitrification and anammox reactor is inoculated with activated sludge, and the sludge inoculation amount accounts for 60%-80% of the volume of the sludge fermentation driving short-cut denitrification and anammox reactor;

[0028] Step S22, after the full-scale nitrification reactor is stably operated, the inlet and outlet of the intermediate water tank are connected with the full-scale nitrification reactor and the sludge fermentation driving short-cut denitrification and anammox reactor, respectively, and the supernatant discharged after the precipitation of the full-scale nitrification reactor is stored in the intermediate water tank;

[0029] a. First, pump the residual sludge in the sludge storage barrel into the sludge fermentation driving short-cut denitrification and anammox reactor;

[0030] b. The initial sludge volume of each cycle is 10% of the sludge fermentation driving short-cut denitrification and anammox reactor, and the sludge in-situ fermentation is carried out;

[0031] c. Then pump the effluent of the full-scale nitrification reactor in the intermediate water tank, and continue to continuously mix under anoxic condition;

[0032] The sludge concentration in the sludge fermentation driving short-cut denitrification and anammox reactor is controlled at 7000-9000 mg / L, and the specific operation cycle includes: sludge feeding for 5-10 min, anoxic stirring for 14-18 h, water feeding for 10-15 min, anoxic stirring for 6-8 h, sludge and water mixture for 15-25 min, and water discharge ratio of 30%-50%;

[0033] Step S23, when the anoxic stirring is completed, the nitrite nitrogen accumulation amount exceeds 10 mg / L and is maintained for 15 days or more, the residual sludge in-situ fermentation driving short-cut denitrification is successfully started.

[0034] Preferably, step S3 is specifically,

[0035] Step S31, a sponge filler frame is fixed in the sludge fermentation driven short-cut denitrification and simultaneous anaerobic ammonia oxidation reactor, and the filler filling ratio is 20%-40% of the sludge fermentation driven short-cut denitrification and simultaneous anaerobic ammonia oxidation reactor;

[0036] Step S32, when the ammonia nitrogen concentration of the sludge fermentation driven short-cut denitrification and simultaneous anaerobic ammonia oxidation reactor is less than 1 mg / L, the total nitrogen removal rate is higher than 90% and is maintained for more than 15 days, the remaining sludge in-situ fermentation, short-cut denitrification / anaerobic ammonia oxidation coupling is completed, that is, the self-enrichment of anaerobic ammonia oxidation bacteria is realized.

[0037] The above-mentioned one remaining sludge in-situ fermentation driven anaerobic ammonia oxidation self-enrichment device and method has the following beneficial effects:

[0038] (1) The domestic sewage is first introduced into the full nitrification reactor, and anoxic denitrification is carried out before aerobic aeration, so that residual NO3 - -N in the previous cycle is removed, then full nitrification is carried out, and NH4 + -N in the raw water is all converted into NO3 - -N. The remaining sludge in the sludge storage barrel is simultaneously introduced into the sludge fermentation driven short-cut denitrification and simultaneous anaerobic ammonia oxidation reactor, short-chain fatty acids generated by in-situ fermentation of the remaining sludge drive short-cut denitrification of NO3 - -N to generate NO2 - -N, and NH4 + -N released by fermentation is gradually established to establish an anaerobic ammonia oxidation reaction, and the sponge filler serves as a carrier to realize rapid enrichment of anaerobic ammonia oxidation bacteria, so that the effect of deep denitrification of domestic sewage and sludge reduction is achieved.

[0039] (2) The realization of short-cut denitrification coupling anaerobic ammonia oxidation in the sludge fermentation driven short-cut denitrification and simultaneous anaerobic ammonia oxidation reactor requires sufficient sludge fermentation effect to achieve good synergy between short-cut denitrification bacteria and anaerobic ammonia oxidation bacteria, and a moderate temperature and weak alkaline environment provides a good environment for sludge fermentation effect, accumulation of NO2 - -N and growth of anaerobic ammonia oxidation bacteria, and the sponge filler in the sludge fermentation driven short-cut denitrification and simultaneous anaerobic ammonia oxidation reactor provides a growth attachment point for anaerobic ammonia oxidation bacteria, thereby improving the retention effect and self-enrichment rate thereof;

[0040] (3) The in-situ enrichment of anaerobic ammonia oxidation bacteria in the present application does not need to inoculate mature anaerobic ammonia oxidation sludge, thereby saving the system start-up cost and improving the stability of initial denitrification performance;

[0041] (4) The short-cut denitrification driven by the in-situ fermentation of the residual sludge in the application does not need special starting strategy, can maintain long-term stable operation, realizes the reduction, resource utilization and stabilization of the residual sludge, and is suitable for deep denitrification of urban sewage and reduction of residual sludge;

[0042] (5) The short-cut denitrification coupled with anaerobic ammonia oxidation in the application can further reduce part of NO3 - -N produced by anaerobic ammonia oxidation, so that the total nitrogen effluent is extremely low.

[0043] The technical solutions of the application are further described in detail below with reference to the drawings and examples. BRIEF DESCRIPTION OF DRAWINGS

[0044] Figure 1 It is a whole structure schematic view of the embodiment of the application of the residual sludge in-situ fermentation driven anaerobic ammonia oxidation self-enrichment device and method.

[0045] REFERENCE NUMERALS

[0046] 1, raw water tank; 101, raw water tank water inlet pump;

[0047] 2, full nitrification reactor; 201, first water inlet; 202, aeration disc; 203, first stirrer; 204, first pH monitor; 205, dissolved oxygen monitor; 206, first water outlet; 207, full nitrification reactor sludge discharge port; 208, full nitrification reactor water pump; 209, full nitrification reactor sludge pump;

[0048] 3, intermediate water tank; 301, second water inlet; 302, second water outlet; 303, intermediate water tank water pump;

[0049] 4, sludge fermentation driven short-cut denitrification simultaneous anaerobic ammonia oxidation reactor; 401, water bath heating rod; 402, top cover; 403, second stirrer; 404, second pH monitor; 405, ORP monitor; 406, sponge packing frame; 407, third water inlet; 408, sludge inlet; 409, third water outlet; 410, reactor sludge discharge port; 411, reactor water pump; 412, reactor sludge pump;

[0050] 5, water outlet bucket; 6, sludge storage bucket; 601, sludge inlet pump; 7, sludge discharge bucket. DETAILED DESCRIPTION

[0051] The technical solutions of the application are further described in detail below with reference to the drawings and examples.

[0052] Unless otherwise defined, the technical terms or scientific terms used in the application shall be understood as the usual meanings understood by those skilled in the art to which the application belongs.

[0053] As Figure 1 The device for promoting self-enrichment of anaerobic ammonia oxidation bacteria by residual sludge in-situ fermentation to produce carbon source to drive short-cut denitrification, as shown in the drawings, comprises a raw water tank 1, a full-scale nitrification reactor 2, an intermediate water tank 3, a sludge fermentation driven short-cut denitrification and simultaneous anaerobic ammonia oxidation reactor 4, and a water outlet bucket 5. The full-scale nitrification reactor 2 is operated in an anoxic / aerobic mode to convert all ammonia nitrogen in municipal sewage into nitrate nitrogen to achieve full-scale nitrification, and the effluent is pumped into the sludge fermentation driven short-cut denitrification and simultaneous anaerobic ammonia oxidation reactor 4.

[0054] The full-scale nitrification reactor 2 is open, and a first water inlet 201 is arranged at the top end of the side close to the raw water tank 1, a full-scale nitrification reactor sludge discharge port 207 is arranged at the bottom end of the side close to the raw water tank 1, and a first water outlet 206 is arranged at the middle of the side close to the intermediate water tank 3. The first water inlet 201 is connected with the output end of the raw water tank water inlet pump 101, and the first water outlet 206 is connected with the input end of the full-scale nitrification reactor water outlet pump 208. The full-scale nitrification reactor sludge discharge port 207 is connected with the sludge storage bucket 6 through the full-scale nitrification reactor sludge discharge pump 209.

[0055] The first water inlet 201 and the first water outlet 206 in the full-scale nitrification reactor 2 are respectively provided with a first pH monitor 204 and a dissolved oxygen monitor 205. The top end of the full-scale nitrification reactor 2 is provided with a first stirrer 203, and the bottom end of the reactor is provided with an aeration disc 202. The middle of the side close to the full-scale nitrification reactor 2 of the intermediate water tank 3 is provided with a second water inlet 301, and the second water inlet 301 is connected with the output end of the full-scale nitrification reactor water outlet pump 208. The bottom of the side close to the reactor of the intermediate water tank 3 is provided with a second water outlet 302, and the second water outlet 302 is connected with the input end of the intermediate water tank water outlet pump 303.

[0056] The sludge fermentation driven short-cut denitrification and simultaneous anaerobic ammonia oxidation reactor 4 has a double-layer structure, the outer layer is provided with a water bath heating rod 401, and the inner layer is provided with a top cover 402, and the reactor inside the top cover 402 is provided with a second stirrer 403. The inner layer bottom of the sludge fermentation driven short-cut denitrification and simultaneous anaerobic ammonia oxidation reactor 4 is provided with a plurality of sponge filler racks 406.

[0057] The inner layer of the sludge fermentation driven short-cut denitrification and simultaneous anaerobic ammonia oxidation reactor 4 near the top of one side of the intermediate water tank 3 is provided with a third water inlet 407, and the third water inlet 407 is connected with the output end of the intermediate water tank water outlet pump 303. The inner layer of the sludge fermentation driven short-cut denitrification and simultaneous anaerobic ammonia oxidation reactor 4 near the bottom of one side of the intermediate water tank 3 is provided with a reactor sludge outlet 410, and the sludge outlet of the sludge fermentation driven short-cut denitrification and simultaneous anaerobic ammonia oxidation reactor 4 is connected with the sludge discharge barrel 7 through a reactor sludge discharge pump 412. The inner layer of the sludge fermentation driven short-cut denitrification and simultaneous anaerobic ammonia oxidation reactor 4 near the top of one side of the water outlet barrel 5 is provided with a sludge inlet 408, and the sludge inlet 408 is connected with the sludge storage barrel 6 through a sludge inlet pump 601.

[0058] The remaining sludge in the sludge storage barrel 6 is pumped into the sludge fermentation driven short-cut denitrification and simultaneous anaerobic ammonia oxidation reactor 4 filled with sponge filler. The carbon source generated by sludge fermentation drives the short-cut denitrification reaction, and the ammonia nitrogen released by sludge fermentation and the nitrite nitrogen produced by short-cut denitrification stimulate the anaerobic ammonia oxidation reaction, promoting the in-situ self-enrichment of anaerobic ammonia oxidation bacteria.

[0059] The inner layer of the sludge fermentation driven short-cut denitrification and simultaneous anaerobic ammonia oxidation reactor 4 near the middle of one side of the water outlet barrel 5 is provided with a third water outlet 409, and the third water outlet 409 is connected with the input end of the reactor water outlet pump 411. The inner layer of the sludge fermentation driven short-cut denitrification and simultaneous anaerobic ammonia oxidation reactor 4 is provided with a second pH monitor 404 and an ORP monitor 405 at the bottom of the third water inlet 407 and the sludge inlet 408, respectively.

[0060] Embodiment

[0061] The in-situ sludge fermentation driven short-cut denitrification / anaerobic ammonia oxidation device is constructed according to the following method to realize the self-enrichment of anaerobic ammonia oxidation bacteria and deep denitrification of wastewater:

[0062] Step S1, start-up and stabilization of the full-scale nitrification reactor 2.

[0063] Step S11, real municipal domestic wastewater is used as raw water, and the ammonia nitrogen concentration is 40-60 mg / L, NO3 - The concentrations of N and NO2 - The concentrations of N and NO2

[0064] Step S12, the activated sludge of the aeration tank of the municipal wastewater treatment plant is inoculated in the full-scale nitrification reactor 2, the sludge concentration after mixing with water is controlled to be 3000-4000 mg / L, and the sludge is periodically discharged to the sludge storage barrel 6 to control the sludge age to be 15-25 days.

[0065] The full nitrification reactor 2 is operated for 6 hours per cycle, 4 cycles per day, including: water inlet for 15 minutes, anoxic stirring for 1 hour and 30 minutes, aerobic aeration for 3 hours, sedimentation for 30 minutes, water outlet for 5 minutes, water outlet ratio is 50%, and idle for 40 minutes.

[0066] After the domestic sewage enters the full nitrification reactor 2, anoxic stirring is first performed, and the organic matter in the domestic sewage is used as a carbon source to reduce the residual NO3 - -N is N2. Then the aeration is opened, the DO is controlled at 2-3 mg / L by the dissolved oxygen monitor 205 and the first pH monitor 204, and the pH value is maintained at 6.5-8.0, the NH4 + -N is completely converted into NO3 - -N.

[0067] Step S13, when the detector reaches the "ammonia valley point", stop aeration and stirring, enter the sedimentation stage, and open the water outlet valve after the sludge settles below half the water level, the supernatant in the full nitrification reactor 2 is discharged into the intermediate water tank 3. When the conversion rate of ammonia nitrogen in raw water to nitrate nitrogen reaches more than 95% and can be stably maintained for more than 7 days, the full nitrification reactor 2 is considered to be stably operated.

[0068] Step S2, start-up of sludge in-situ fermentation driving short-cut denitrification.

[0069] Step S21, the sludge fermentation driving short-cut denitrification simultaneous anaerobic ammonia oxidation reactor 4 is always maintained at 35±2°C water bath heating during operation, and the pH is 9.0.

[0070] The sludge fermentation driving short-cut denitrification simultaneous anaerobic ammonia oxidation reactor 4 is inoculated with activated sludge (remaining sludge in the secondary sedimentation tank), and the sludge inoculation amount accounts for 80% of the volume of the sludge fermentation driving short-cut denitrification simultaneous anaerobic ammonia oxidation reactor 4.

[0071] Step S22, after the full nitrification reactor 2 is stably operated, the inlet and outlet of the intermediate water tank 3 are connected with the full nitrification reactor 2 and the sludge fermentation driving short-cut denitrification simultaneous anaerobic ammonia oxidation reactor 4 respectively, and the supernatant discharged after sedimentation of the full nitrification reactor 2 is stored in the intermediate water tank 3.

[0072] a, first pump the remaining sludge in the sludge storage barrel 6 into the sludge fermentation driving short-cut denitrification simultaneous anaerobic ammonia oxidation reactor 4.

[0073] b, the initial sludge volume per cycle is 10% of the sludge fermentation driving short-cut denitrification simultaneous anaerobic ammonia oxidation reactor 4, and the sludge in-situ fermentation is performed.

[0074] c. The sludge is fermented in situ for 18 hours to accumulate sufficient carbon source, and then the effluent of the full-scale nitrification reactor 2 in the intermediate water tank 3 is pumped in.

[0075] The sludge fermentation drives the sludge concentration in the sludge fermentation-driven short-cut denitrification and ANAMMOX reactor 4 to be controlled at 8000-9000 mg / L. The specific operation cycle includes: sludge feeding for 5 minutes, anoxic stirring for 18 hours, water feeding for 10 minutes, anoxic stirring for 4 hours to achieve short-cut denitrification. Sedimentation for 1 hour and 30 minutes, sludge and water mixture for 15 minutes, and water drainage ratio of 30%.

[0076] During this period, the pH in the sludge fermentation-driven short-cut denitrification and ANAMMOX reactor 4 is maintained at 8.5-9.0, and the weak alkaline environment promotes the hydrolysis of the residual sludge to release short-chain fatty acids and NH4 + -N, and the short-chain fatty acids act as carbon sources to drive the short-cut denitrification of NO3 - -N, and the reduced NO2 - -N and NH4 + -N provide substrates for ANAMMOX.

[0077] Step S23: When the anoxic stirring is completed and the nitrite accumulation exceeds 10 mg / L and is maintained for more than 15 days, it is considered that the residual sludge in situ fermentation-driven short-cut denitrification is successfully started.

[0078] Step S3: Realization of self-enrichment of ANAMMOX bacteria in the sludge fermentation-driven short-cut denitrification and ANAMMOX reactor 4.

[0079] Step S31: Fixing the sponge filler frame 406 in the sludge fermentation-driven short-cut denitrification and ANAMMOX reactor 4, and the filler filling ratio is 30% of the sludge fermentation-driven short-cut denitrification and ANAMMOX reactor 4. The sponge filler provides growth attachment points for ANAMMOX bacteria, and with the continuous supply of NH4 + -N and NO2 - -N, the ANAMMOX bacteria can grow.

[0080] Step S32: When the ammonia nitrogen concentration NH4 + -N in the effluent of the sludge fermentation-driven short-cut denitrification and ANAMMOX reactor 4 is less than 1 mg / L, the total nitrogen removal rate is higher than 90% and is maintained for more than 15 days, the coupling of residual sludge in situ fermentation, short-cut denitrification / ANAMMOX is completed. The flocculent sludge and sponge filler are taken out, and qPCR detection is performed on the ANAMMOX-related genes. When the ANAMMOX gene copy number reaches an order of magnitude of 10 times the initial value, it is considered that the self-enrichment of ANAMMOX bacteria is completed.

[0081] Therefore, the application adopts the above-mentioned device and method for in-situ self-enrichment of anaerobic ammonia oxidation driven by residual sludge fermentation to realize resource utilization of residual sludge without additional carbon source by taking the carbon source generated by residual sludge fermentation as an electron donor to drive short-cut denitrification / anaerobic ammonia oxidation reaction, and to realize in-situ self-enrichment of anaerobic ammonia oxidation bacteria by using sponge filler as a carrier, thereby constructing an integrated sludge fermentation synchronous short-cut denitrification / anaerobic ammonia oxidation system, which can provide a solution for deep denitrification of municipal wastewater and sludge reduction, and has important significance for realizing sustainable urban domestic wastewater treatment.

[0082] Finally, it should be noted that: the above examples are only used to illustrate the technical solutions of the present application rather than limit it, although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that: the technical solutions of the present application can still be modified or replaced by equivalents, and these modifications or equivalent replacements cannot make the modified technical solutions deviate from the spirit and scope of the technical solutions of the present application.

Claims

1. A method for in-situ fermentation-driven auto-enrichment of anaerobic ammonia oxidation by excess sludge, characterized in that: The device used in the method comprises a raw water tank, a full nitrification reactor, an intermediate water tank, a sludge fermentation driven short-cut denitrification and simultaneous anaerobic ammonia oxidation reactor, and a water outlet bucket; the raw water tank, the full nitrification reactor, the intermediate water tank, and the sludge fermentation driven short-cut denitrification and simultaneous anaerobic ammonia oxidation reactor are connected by a raw water tank water inlet pump, a full nitrification reactor water outlet pump, an intermediate water tank water outlet pump, and a reactor water outlet pump, respectively; The full nitrification reactor is open, and a first water inlet is arranged at the top end of the side close to the raw water tank, and a full nitrification reactor sludge discharge port is arranged at the bottom end of the side close to the raw water tank, and a first water outlet is arranged at the middle of the side close to the intermediate water tank; The first water inlet is connected with the output end of the raw water tank water inlet pump, and the first water outlet is connected with the input end of the full nitrification reactor water outlet pump; the full nitrification reactor sludge discharge port is connected with the sludge storage tank through a full nitrification reactor sludge discharge pump; The first water inlet and the first water outlet in the full nitrification reactor are respectively provided with a first pH monitor and a dissolved oxygen monitor; a first stirrer is arranged at the top end in the full nitrification reactor, and an aeration disc is arranged at the bottom end in the full nitrification reactor; The intermediate water tank is provided with a second water inlet at the middle of the side close to the full nitrification reactor, and the second water inlet is connected with the output end of the full nitrification reactor water outlet pump; the intermediate water tank is provided with a second water outlet at the bottom of the side close to the reactor, and the second water outlet is connected with the input end of the intermediate water tank water outlet pump; The sludge fermentation driven short-cut denitrification and simultaneous anaerobic ammonia oxidation reactor has a double-layer structure, and is provided with a water bath heating rod at the outer layer and a top cover at the inner layer; a second stirrer is arranged in the sludge fermentation driven short-cut denitrification and simultaneous anaerobic ammonia oxidation reactor on the top cover; a plurality of sponge filler racks are arranged at the bottom of the inner layer of the sludge fermentation driven short-cut denitrification and simultaneous anaerobic ammonia oxidation reactor; The inner layer of the sludge fermentation driven short-cut denitrification and simultaneous anaerobic ammonia oxidation reactor is provided with a third water inlet at the top of the side close to the intermediate water tank, and the third water inlet is connected with the output end of the intermediate water tank water outlet pump; The inner layer of the sludge fermentation driven short-cut denitrification and simultaneous anaerobic ammonia oxidation reactor is provided with a reactor sludge discharge port at the bottom of the side close to the intermediate water tank, and the reactor sludge discharge port is connected with the sludge discharge tank through a reactor sludge discharge pump; The inner layer of the sludge fermentation driven short-cut denitrification and simultaneous anaerobic ammonia oxidation reactor is provided with a sludge inlet at the top of the side close to the water outlet bucket, and the sludge inlet is connected with the sludge storage tank through a sludge inlet pump; the inner layer of the sludge fermentation driven short-cut denitrification and simultaneous anaerobic ammonia oxidation reactor is provided with a third water outlet at the middle of the side close to the water outlet bucket, and the third water outlet is connected with the input end of the reactor water outlet pump; The third water inlet and the sludge inlet of the inner layer of the sludge fermentation driven short-cut denitrification and simultaneous anaerobic ammonia oxidation reactor are respectively provided with a second pH monitor and an ORP monitor; The method comprises the following steps: Step S1, starting and stabilizing the full nitrification reactor; Step S11, using municipal domestic sewage as raw water, wherein the ammonia nitrogen concentration is 30-60 mg / L, and the raw water is injected into the full nitrification reactor through a raw water pump; Step S12, inoculate the activated sludge from the aeration tank of the municipal wastewater treatment plant into the full nitrification reactor, control the sludge concentration after mixing with water to be 2000-5000 mg / L, and regularly discharge sludge from the sludge storage barrel to control the sludge age to be 15-25 days; Wherein, the operation cycle of the full nitrification reactor is 4-8h, 3-6 cycles per day, including: water inlet 10-15min, anoxic stirring 1-2h, aerobic aeration 3-4h, dissolved oxygen control at 2-3mg / L, pH value maintained at 6.5-8.5, sedimentation 30min, drainage 5-10min, drainage ratio 50%-70%; Step S13, when the conversion rate of ammonia nitrogen to nitrate nitrogen in raw water reaches more than 95% and can be stably maintained for more than 7 days, the full nitrification reactor is stably operated; Step S2, start-up of residual sludge in-situ fermentation driving short-cut denitrification; Step S21, during the operation of the sludge fermentation driving short-cut denitrification simultaneous anaerobic ammonia oxidation reactor, the water bath heating is always maintained at 35±2℃, and the pH value is 8.5-9.0; Inoculate the activated sludge into the sludge fermentation driving short-cut denitrification simultaneous anaerobic ammonia oxidation reactor, and the sludge inoculation amount accounts for 60%-80% of the volume of the sludge fermentation driving short-cut denitrification simultaneous anaerobic ammonia oxidation reactor; Step S22, after the full nitrification reactor is stably operated, connect the inlet and outlet of the intermediate water tank with the full nitrification reactor and the sludge fermentation driving short-cut denitrification simultaneous anaerobic ammonia oxidation reactor respectively, and store the supernatant discharged from the full nitrification reactor after sedimentation in the intermediate water tank; a. First, pump the residual sludge in the sludge storage barrel into the sludge fermentation driving short-cut denitrification simultaneous anaerobic ammonia oxidation reactor; b. The initial sludge volume per cycle is 10% of the sludge fermentation driving short-cut denitrification simultaneous anaerobic ammonia oxidation reactor, and the sludge in-situ fermentation is carried out; c. Then, pump the effluent of the full nitrification reactor in the intermediate water tank, and continue to sustain anoxic stirring; Wherein, the sludge concentration in the sludge fermentation driving short-cut denitrification simultaneous anaerobic ammonia oxidation reactor is controlled at 7000-9000 mg / L, and the specific operation cycle includes: sludge inlet 5-10min, anoxic stirring 14-18h, water inlet 10-15min, anoxic stirring 6-8h, sludge-water mixture discharge 15-25min, drainage ratio 30%-50%; Step S23, when the nitrite nitrogen accumulation exceeds 10 mg / L after anoxic stirring and is maintained for more than 15 days, the residual sludge in-situ fermentation driving short-cut denitrification is successfully started; Step S3, realization of anaerobic ammonia oxidation bacteria self-enrichment; Step S31, fix the sponge filler frame in the sludge fermentation driving short-cut denitrification simultaneous anaerobic ammonia oxidation reactor, and the filler filling ratio is 20%-40% of the sludge fermentation driving short-cut denitrification simultaneous anaerobic ammonia oxidation reactor; Step S32, when the ammonia nitrogen concentration of the effluent of the sludge fermentation driving short-cut denitrification simultaneous anaerobic ammonia oxidation reactor is <1 mg / L, and the total nitrogen removal rate is higher than 90% and is maintained for more than 15 days, the coupling of residual sludge in-situ fermentation, short-cut denitrification / anaerobic ammonia oxidation is completed, that is, the anaerobic ammonia oxidation bacteria self-enrichment is realized.

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