Device and method for driving anaerobic ammonia oxidation self-enrichment by in-situ fermentation of excess sludge

Abstract

The invention discloses a residual sludge in-situ fermentation driven anaerobic ammonia oxidation self-enrichment device and method. The device comprises a raw water tank, a whole-process nitrification reactor, a middle water tank, a reactor sludge fermentation driven short-range denitrification synchronous anaerobic ammonia oxidation reactor and a water outlet bucket. According to the residual sludge in-situ fermentation driven anaerobic ammonia oxidation self-enrichment device and method, a carbon source generated by residual sludge fermentation is used as an electron donor to drive short-cut denitrification / anaerobic ammonia oxidation reaction, and residual sludge recycling is achieved under the condition that an external carbon source is not needed; and sponge filler is used as a carrier for in-situ self-enrichment of anaerobic ammonium oxidation bacteria, so that an integrated sludge fermentation synchronous short-cut denitrification / anaerobic ammonium oxidation system is constructed, a solution can be provided for advanced nitrogen removal and sludge reduction of urban sewage, and the method has important significance for realizing sustainable urban domestic sewage treatment.

Description

Technical Field

[0001] The invention belongs to the technical field of excess sludge biochemical treatment and sewage biological denitrification treatment, and specifically relates to an excess sludge in-situ fermentation driven anaerobic ammonia oxidation self-enrichment device and method. Background Art

[0002] Traditional sewage denitrification has the disadvantages of large sludge production and high energy consumption. The low C / N ratio of urban sewage also makes the biological denitrification performance unstable. Anaerobic ammonium oxidation can convert ammonia nitrogen (NH 4 + -N) as an electron donor, nitrite (NO 2 - -N) as an electron acceptor for biological denitrification to produce nitrogen gas (N 2 ) and nitrate (NO 3 - -N), is considered a promising autotrophic denitrification strategy due to its low energy consumption and the absence of an organic carbon source. However, the low growth rate of anaerobic ammonium oxidizing bacteria and the volatility of urban sewage make their natural enrichment slow, hindering their scale-up application in mainstream anaerobic ammonium oxidation technology.

[0003] Continuous NO 2 - -N supply is the key to the application of anaerobic ammonium oxidation in urban sewage treatment. 2 - -N substrate has two pathways: short-range nitrification (NH 4 + -N → NO 2 - -N) and short-range denitrification (NO 3 - -N → NO 2 - -N). In recent decades, the research on short-term nitrification coupled with anaerobic ammonium oxidation has mainly focused on mainstream wastewater treatment. In order to further reduce the nitrate concentration in the effluent, short-term denitrification coupled with anaerobic ammonium oxidation was proposed, which can further reduce organic matter and oxygen demand without NOB washing. In addition, sludge fermentation can degrade sludge macromolecules into small molecules, and the short-chain fatty acids produced can drive the short-term denitrification process as a carbon source, releasing NH 4 + -N can serve as a substrate for anaerobic ammonium oxidation. The combination of sludge fermentation and short-range denitrification coupled with anaerobic ammonium oxidation can improve the stability of the anaerobic ammonium oxidation process and achieve efficient removal of total nitrogen (TIN) and sludge reduction.

[0004] Since the abundance of anaerobic ammonium-oxidizing bacteria in sludge is very low, in order to accelerate the start-up of the autotrophic denitrification system, part of the anaerobic ammonium-oxidizing sludge is usually inoculated in the reaction system. Therefore, in practical applications, the investment and operation complexity will be increased to a certain extent. In contrast, in situ self-enrichment of anaerobic ammonium-oxidizing bacteria will be a more practical and effective stable operation strategy. Through long-term and stable NH 4 + -N and NO 2 - -N supply and supplementing fillers as growth carriers will help the self-enrichment process of anaerobic ammonium oxidizing bacteria. Therefore, the art needs to develop a residual sludge in-situ fermentation driven anaerobic ammonium oxidation self-enrichment device and method that can effectively solve the above problems. Summary of the invention

[0005] The purpose of the present invention is to provide an anaerobic ammonium oxidation self-enrichment device and method driven by in-situ fermentation of excess sludge, using the carbon source produced by the fermentation of excess sludge as an electron donor to drive the short-range denitrification / anaerobic ammonium oxidation reaction, realizing the resource utilization of excess sludge without the need for an external carbon source, and using sponge fillers as carriers for in-situ self-enrichment of anaerobic ammonium oxidizing bacteria to construct an integrated sludge fermentation synchronous short-range denitrification / anaerobic ammonium oxidation system, which can provide a solution for deep denitrification and sludge reduction of urban sewage, and is of great significance for achieving sustainable urban domestic sewage treatment.

[0006] To achieve the above-mentioned purpose, the present invention provides a residual sludge in-situ fermentation driven anaerobic ammonium oxidation self-enrichment device, comprising a raw water tank, a full-process nitrification reactor, an intermediate water tank, a sludge fermentation driven short-term denitrification synchronous anaerobic ammonium oxidation reactor, and a water outlet bucket; the raw water tank and the full-process nitrification reactor, the full-process nitrification reactor and the intermediate water tank, the intermediate water tank and the sludge fermentation driven short-term denitrification synchronous anaerobic ammonium oxidation reactor, and the sludge fermentation driven short-term denitrification synchronous anaerobic ammonium oxidation reactor and the water outlet bucket are connected respectively through a raw water tank inlet pump, a full-process nitrification reactor outlet pump, an intermediate water tank outlet pump, and a reactor outlet pump.

[0007] Preferably, the full-process nitrification reactor is configured to be open, with a first water inlet provided at the top of the side close to the raw water tank, a full-process nitrification reactor mud outlet provided at the bottom of the side close to the raw water tank, and a first water outlet provided in the middle of the side close to the intermediate water tank; The first water inlet is connected to the output end of the raw water tank inlet pump, and the first water outlet is connected to the input end of the full-process nitrification reactor outlet pump; the full-process nitrification reactor mud outlet is connected to the mud storage barrel through the full-process nitrification reactor mud pump.

[0008] Preferably, a first pH monitor and a dissolved oxygen monitor are respectively provided on the first water inlet and the first water outlet inside the full-process nitrification reactor; a first stirrer is provided at the top of the full-process nitrification reactor, and an aeration disk is provided at the bottom of the full-process nitrification reactor.

[0009] Preferably, a second water inlet is provided in the middle of the intermediate water tank close to the full-process nitrification reactor, and the second water inlet is connected to the output end of the water outlet pump of the full-process nitrification reactor; a second water outlet is provided at the bottom of the intermediate water tank close to the reactor, and the second water outlet is connected to the input end of the water outlet pump of the intermediate water tank.

[0010] Preferably, the sludge fermentation driven short-range denitrification synchronous anaerobic ammonium oxidation reactor has a double-layer structure, the outer layer of which is provided with a water bath heating rod, and the inner layer is provided with a top cover, and a second agitator is provided inside the sludge fermentation driven short-range denitrification synchronous anaerobic ammonium oxidation reactor on the top cover; a plurality of sponge filling racks are provided at the bottom of the inner layer of the sludge fermentation driven short-range denitrification synchronous anaerobic ammonium oxidation reactor.

[0011] Preferably, a third water inlet is provided on the top of the inner layer of the sludge fermentation driven short-range denitrification synchronous anaerobic ammonium oxidation reactor close to the intermediate water tank, and the third water inlet is connected to the output end of the water outlet pump of the intermediate water tank; A reactor sludge discharge port is provided at the bottom of the inner layer of the sludge fermentation driven short-range denitrification synchronous anaerobic ammonium oxidation reactor close to the intermediate water tank, and the reactor sludge discharge port is connected to a sludge discharge barrel through a reactor sludge discharge pump.

[0012] Preferably, a sludge inlet is provided on the top of the inner layer of the sludge fermentation driven short-range denitrification synchronous anaerobic ammonium oxidation reactor close to the water outlet bucket, and the sludge inlet is connected to the sludge storage bucket through a sludge inlet pump; A third water outlet is provided in the middle of the inner layer of the sludge fermentation driven short-range denitrification synchronous anaerobic ammonium oxidation reactor close to the water outlet bucket, and the third water outlet is connected to the input end of the reactor water outlet pump; The second pH monitor and the ORP monitor are respectively arranged at the bottom of the inner third water inlet and the mud inlet of the sludge fermentation driven short-range denitrification synchronous anaerobic ammonium oxidation reactor.

[0013] A method for self-enrichment of anaerobic ammonium oxidation driven by in-situ fermentation of excess sludge, comprising the following steps: Step S1, starting and stabilizing the whole nitration reactor; Step S11, using urban domestic sewage as raw water, wherein the ammonia nitrogen concentration is 30-60 mg / L, and injecting it into the full-process nitrification reactor through a raw water pump; Step S12, inoculating the activated sludge from the aeration tank of the municipal sewage treatment plant in the whole nitrification reactor, controlling the sludge concentration after the sludge and water are mixed to 2000-5000 mg / L, and regularly discharging the sludge into the sludge storage barrel to control the sludge age to 15-25 days; Among them, each operation cycle of the whole 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 controlled at 2-3mg / L, pH maintained at 6.5-8.5, sedimentation 30min, drainage 5-10min, drainage ratio of 50%-70%; Step S13: When the conversion rate of ammonia nitrogen in the raw water into nitrate nitrogen reaches more than 95% and can be stably maintained for more than 7 days, the whole nitrification reactor operates stably; Step S2, starting short-range denitrification driven by in-situ fermentation of excess sludge; Step S3, realization of self-enrichment of anaerobic ammonium-oxidizing bacteria.

[0014] Preferably, step S2 specifically comprises: Step S21, during the operation of the sludge fermentation driven short-range denitrification synchronous anaerobic ammonium oxidation reactor, the water bath heating at 35±2° C. and the pH value at 8.5-9.0 are always maintained; The activated sludge is inoculated in the sludge fermentation driven short-cut denitrification synchronous anaerobic ammonium oxidation reactor, and the sludge inoculation amount accounts for 60%-80% of the volume of the sludge fermentation driven short-cut denitrification synchronous anaerobic ammonium oxidation reactor; Step S22, after the full nitrification reactor is stably running, the water inlet and outlet of the intermediate water tank are respectively connected to the full nitrification reactor and the sludge fermentation driven short-range denitrification synchronous anaerobic ammonium oxidation reactor, and the supernatant discharged after the precipitation of the full nitrification reactor is stored in the intermediate water tank; a. First, the residual sludge in the sludge storage tank is pumped into the sludge fermentation driven short-range denitrification synchronous anaerobic ammonium oxidation reactor; b. The sludge volume at the beginning of each cycle is 10% of the sludge fermentation driven short-range denitrification synchronous anaerobic ammonium oxidation reactor, and the sludge is fermented in situ; c. Then pump the effluent from the full-process nitrification reactor into the intermediate water tank and continue to stir with anoxic stirring; Among them, the sludge concentration in the sludge fermentation-driven short-range denitrification synchronous anaerobic ammonium oxidation reactor is controlled at 7000-9000 mg / L. The specific operation cycle includes: sludge inlet 5-10 minutes, anoxic stirring 14-18 hours, water inlet 10-15 minutes, anoxic stirring 6-8 hours, sludge and water mixture discharge 15-25 minutes, and drainage ratio 30%-50%; Step S23: When the accumulation of nitrite nitrogen exceeds 10 mg / L after the anoxic stirring and is maintained for more than 15 days, the short-range denitrification driven by the in-situ fermentation of the residual sludge is successfully started.

[0015] Preferably, step S3 specifically comprises: Step S31, fixing a sponge filler frame in the sludge fermentation driven short-range denitrification synchronous anaerobic ammonium oxidation reactor, wherein the filler filling ratio is 20%-40% of that in the sludge fermentation driven short-range denitrification synchronous anaerobic ammonium oxidation reactor; Step S32: When the effluent ammonia nitrogen concentration of the anaerobic ammonium oxidation reactor driven by sludge fermentation is less than 1 mg / L and the total nitrogen removal rate is higher than 90% and maintained for more than 15 days, the coupling of the in-situ fermentation of the residual sludge and the short-term denitrification / anaerobic ammonium oxidation is completed, and the self-enrichment of the anaerobic ammonium oxidizing bacteria is achieved.

[0016] The present invention adopts the above-mentioned excess sludge in-situ fermentation driven anaerobic ammonia oxidation self-enrichment device and method, and the beneficial effects are as follows: (1) In the present invention, domestic sewage first enters the full-process nitrification reactor, and performs anoxic denitrification before aerobic aeration to remove residual NO in the previous cycle. 3 - -N, and then aerobic nitrification is carried out to convert NH 4 + -N is converted to NO 3 - -N. The residual sludge in the sludge storage tank enters the sludge fermentation-driven short-range denitrification synchronous anaerobic ammonium oxidation reactor at the same time. The short-chain fatty acids produced by the in-situ fermentation of the residual sludge serve as a carbon source to drive NO 3 - Short-term denitrification of -N produces NO 2 - -N, and the additional NH released by fermentation 4 + -N gradually establishes the anaerobic ammonium oxidation reaction, and the sponge filler is used as a carrier to achieve the rapid enrichment of anaerobic ammonium oxidizing bacteria, ultimately achieving the effect of deep denitrification of domestic sewage and sludge reduction; (2) Sludge fermentation drives short-cut denitrification and synchronizes anaerobic ammonium oxidation. The realization of short-cut denitrification coupled with anaerobic ammonium oxidation in the reactor requires sufficient sludge fermentation effect to achieve good synergy between short-cut denitrifying bacteria and anaerobic ammonium oxidizing bacteria. The moderate and weakly alkaline environment is conducive to the sludge fermentation effect, NO 2 - -N accumulation and the growth of anaerobic ammonium oxidizing bacteria provide a good environment. The sponge filler in the reactor of the sludge fermentation-driven short-range denitrification synchronous anaerobic ammonium oxidation reactor provides growth attachment points for anaerobic ammonium oxidizing bacteria, thereby improving their retention effect and self-enrichment rate. (3) The in-situ enrichment of anaerobic ammonium-oxidizing bacteria in the present invention does not require inoculation of mature anaerobic ammonium-oxidizing sludge, which saves system startup costs and improves the stability of initial denitrification performance; (4) The short-range denitrification driven by in-situ fermentation of excess sludge in the present invention does not require a special startup strategy and can maintain long-term stable operation, thereby achieving the reduction, resource utilization and stabilization of excess sludge, and is suitable for deep denitrification of urban sewage and excess sludge reduction; (5) Short-range denitrification coupled with anaerobic ammonium oxidation in the present invention can further reduce part of the NO produced by anaerobic ammonium oxidation 3 - -N, achieving extremely low total nitrogen effluent.

[0017] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the overall structure of an embodiment of an anaerobic ammonia oxidation self-enrichment device and method driven by in-situ fermentation of excess sludge in the present invention.

[0019] Reference numerals 1. Raw water tank; 101. Raw water tank inlet pump; 2. Full-process nitrification reactor; 201. First water inlet; 202. Aeration plate; 203. First agitator; 204. First pH monitor; 205. Dissolved oxygen monitor; 206. First water outlet; 207. Full-process nitrification reactor mud outlet; 208. Full-process nitrification reactor water outlet pump; 209. Full-process nitrification reactor mud pump; 3. Intermediate water tank; 301. Second water inlet; 302. Second water outlet; 303. Intermediate water tank outlet pump; 4. Sludge fermentation driven short-range denitrification synchronous anaerobic ammonium oxidation reactor; 401, water bath heating rod; 402, top cover; 403, second agitator; 404, second pH monitor; 405, ORP monitor; 406, sponge filler rack; 407, third water inlet; 408, mud inlet; 409, third water outlet; 410, reactor mud outlet; 411, reactor water outlet pump; 412, reactor mud pump; 5. Water outlet bucket; 6. Mud storage bucket; 601. Mud inlet pump; 7. Mud discharge bucket. DETAILED DESCRIPTION

[0020] The technical solution of the present invention is further described below through the accompanying drawings and embodiments.

[0021] Unless otherwise defined, technical or scientific terms used in the present invention shall have the common meanings understood by one having ordinary skills in the field to which the present invention belongs.

[0022] like Figure 1As shown, a device for in-situ fermentation of excess sludge to produce carbon sources drives short-term denitrification and promotes self-enrichment of anaerobic ammonium oxidizing bacteria, comprising a raw water tank 1, a full-process nitrification reactor 2, an intermediate water tank 3, a sludge fermentation driven short-term denitrification synchronous anaerobic ammonium oxidation reactor 4, and a water outlet bucket 5. The full-process nitrification reactor 2 operates in anoxic / aerobic mode, converting all ammonia nitrogen in urban domestic sewage into nitrate nitrogen to achieve a full-process nitrification reaction, and its effluent is pumped into the sludge fermentation driven short-term denitrification synchronous anaerobic ammonium oxidation reactor 4.

[0023] The full-range nitrification reactor 2 is set to be open, with a first water inlet 201 at the top of the side close to the raw water tank 1, a full-range nitrification reactor mud outlet 207 at the bottom of the side close to the raw water tank 1, and a first water outlet 206 at the middle of the side close to the intermediate water tank 3. The first water inlet 201 is connected to the output end of the raw water tank inlet pump 101, and the first water outlet 206 is connected to the input end of the full-range nitrification reactor water outlet pump 208. The full-range nitrification reactor mud outlet 207 is connected to the mud storage barrel 6 through the full-range nitrification reactor mud pump 209.

[0024] The first water inlet 201 and the first water outlet 206 of the whole nitrification reactor 2 are respectively provided with a first pH monitor 204 and a dissolved oxygen monitor 205. A first agitator 203 is provided at the top of the whole nitrification reactor 2, and an aeration plate 202 is provided at the bottom of the reactor. A second water inlet 301 is provided in the middle of the intermediate water tank 3 near the whole nitrification reactor 2, and the second water inlet 301 is connected to the output end of the whole nitrification reactor outlet pump 208. A second water outlet 302 is provided at the bottom of the intermediate water tank 3 near the reactor, and the second water outlet 302 is connected to the input end of the intermediate water tank outlet pump 303.

[0025] The sludge fermentation driven short-range denitrification synchronous anaerobic ammonium oxidation reactor 4 is a double-layer structure, the outer layer is provided with a water bath heating rod 401, the inner layer is provided with a top cover 402, and the reactor is provided with a second agitator 403 on the top cover 402. The inner bottom of the inner layer of the sludge fermentation driven short-range denitrification synchronous anaerobic ammonium oxidation reactor 4 is provided with a plurality of sponge filler racks 406.

[0026] A third water inlet 407 is provided at the top of the inner layer of the sludge fermentation driven short-distance denitrification synchronous anaerobic ammonium oxidation reactor 4 near the intermediate water tank 3, and the third water inlet 407 is connected to the output end of the intermediate water tank outlet pump 303. A reactor mud discharge port 410 is provided at the bottom of the inner layer of the sludge fermentation driven short-distance denitrification synchronous anaerobic ammonium oxidation reactor 4 near the intermediate water tank 3, and the mud discharge port of the sludge fermentation driven short-distance denitrification synchronous anaerobic ammonium oxidation reactor 4 is connected to the mud discharge barrel 7 through the reactor mud discharge pump 412. A mud inlet 408 is provided at the top of the inner layer of the sludge fermentation driven short-distance denitrification synchronous anaerobic ammonium oxidation reactor 4 near the outlet barrel 5, and the mud inlet 408 is connected to the mud storage barrel 6 through the mud inlet pump 601.

[0027] The residual sludge in the sludge storage barrel 6 is pumped into the sludge fermentation driven short-range denitrification synchronous anaerobic ammonium oxidation reactor 4 filled with sponge filler. The carbon source produced by the sludge fermentation drives the short-range denitrification reaction. The ammonia nitrogen released by the sludge fermentation and the nitrite nitrogen produced by the short-range denitrification stimulate the anaerobic ammonium oxidation reaction, thereby promoting the in-situ self-enrichment of anaerobic ammonium oxidizing bacteria.

[0028] A third water outlet 409 is provided in the middle of the inner layer of the sludge fermentation driven short-range denitrification synchronous anaerobic ammonium oxidation reactor 4 near the water outlet bucket 5, and the third water outlet 409 is connected to the input end of the reactor outlet pump 411. A second pH monitor 404 and an ORP monitor 405 are provided at the bottom of the inner layer third water inlet 407 and mud inlet 408 of the sludge fermentation driven short-range denitrification synchronous anaerobic ammonium oxidation reactor 4, respectively.

[0029] Example The in-situ sludge fermentation-driven short-range denitrification / anaerobic ammonium oxidation device was constructed according to the following method to achieve self-enrichment of anaerobic ammonium oxidizing bacteria and deep denitrification of sewage: Step S1, starting and stabilizing the whole nitration reactor 2.

[0030] Step S11: Use real urban domestic sewage as raw water, where the concentration of ammonia nitrogen is 40-60 mg / L, NO 3 - -N and NO 2 - The concentration of -N is less than 0.5 mg / L and is injected into the full-process nitrification reactor 2 through the raw water pump.

[0031] Step S12, the activated sludge from the aeration tank of the municipal sewage treatment plant is inoculated in the full nitrification reactor 2, the sludge concentration after the sludge and water are mixed is controlled to be 3000-4000 mg / L, and the sludge is regularly discharged to the sludge storage tank 6 to control the sludge age to be 15-25 days.

[0032] Each operation cycle of the full-process nitrification reactor 2 is 6 hours, with 4 cycles per day, including: water inlet 15 minutes, anoxic stirring 1 hour and 30 minutes, aerobic aeration 3 hours, sedimentation 30 minutes, drainage 5 minutes, drainage ratio of 50%, and idle 40 minutes.

[0033] After the domestic sewage enters the full-process nitrification reactor 2, it is first anoxic and stirred, and the organic matter in the domestic sewage is used as a carbon source to reduce the residual NO in the previous cycle. 3 - -N is N 2 Then the aeration is turned on, and the DO is controlled at 2-3 mg / L and the pH value is maintained at 6.5-8.0 by the dissolved oxygen monitor 205 and the first pH monitor 204. 4 +-N is completely converted into NO under the action of AOB and NOB 3 - -N.

[0034] Step S13, when the detector reaches the "ammonia valley point", aeration and stirring are stopped, and the sedimentation stage is entered. After the sludge settles below half the water level, the drain valve is opened, and the supernatant in the full nitrification reactor 2 is discharged into the intermediate water tank 3. When the conversion rate of ammonia nitrogen in the 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 in stable operation.

[0035] Step S2: In-situ fermentation of excess sludge drives the initiation of short-range denitrification.

[0036] Step S21, during the operation of the sludge fermentation driven short-range denitrification synchronous anaerobic ammonium oxidation reactor 4, water bath heating at 35±2° C. and a pH of 9.0 are always maintained.

[0037] The activated sludge (residual sludge from the secondary sedimentation tank) is inoculated in the sludge fermentation driven short-cut denitrification synchronous anaerobic ammonium oxidation reactor 4, and the sludge inoculation amount accounts for 80% of the volume of the sludge fermentation driven short-cut denitrification synchronous anaerobic ammonium oxidation reactor 4.

[0038] Step S22, after the full-process nitrification reactor 2 is running stably, the water inlet and outlet of the intermediate water tank 3 are connected to the full-process nitrification reactor 2 and the sludge fermentation-driven short-term denitrification synchronous anaerobic ammonia oxidation reactor 4 respectively, and the supernatant discharged from the full-process nitrification reactor 2 after sedimentation is stored in the intermediate water tank 3.

[0039] a. First, the residual sludge in the sludge storage tank 6 is pumped into the sludge fermentation-driven short-range denitrification synchronous anaerobic ammonium oxidation reactor 4.

[0040] b. The sludge volume at the beginning of each cycle is 10% of the sludge fermentation-driven short-range denitrification synchronous anaerobic ammonium oxidation reactor 4, and the sludge is fermented in situ.

[0041] c. Carry out in-situ fermentation of the sludge for 18 hours to accumulate sufficient carbon source, and then pump the effluent of the full-process nitrification reactor 2 into the intermediate water tank 3, and continue to stir anoxically.

[0042] The sludge concentration in the anaerobic ammonia oxidation reactor 4 driven by sludge fermentation is controlled at 8000-9000 mg / L, and the specific operation cycle includes: sludge inlet for 5 minutes, anoxic stirring for 18 hours, water inlet for 10 minutes, anoxic stirring for 4 hours to achieve short-range denitrification, sedimentation for 1h30min, sludge-water mixture discharge for 15 minutes, and drainage ratio of 30%.

[0043] During this period, the pH in the anaerobic ammonium oxidation reactor 4 driven by sludge fermentation was maintained at 8.5-9.0, and the weakly alkaline environment caused the residual sludge to hydrolyze, releasing short-chain fatty acids and NH 4 + -N, short-chain fatty acids act as carbon sources to drive NO 3 - -N short-range denitrification, reducing NO 2 - -N and NH 4 + -N provides substrate for anaerobic ammonium oxidation.

[0044] Step S23: When the accumulation of nitrite nitrogen exceeds 10 mg / L after the anoxic stirring and is maintained for more than 15 days, it is regarded as the successful start of short-range denitrification driven by in-situ fermentation of residual sludge.

[0045] Step S3, sludge fermentation drives the self-enrichment of anaerobic ammonium oxidizing bacteria in the short-range denitrification synchronous anaerobic ammonium oxidation reactor 4.

[0046] Step S31, fix the sponge filler frame 406 in the sludge fermentation driven short-range denitrification synchronous anaerobic ammonium oxidation reactor 4, and the filler filling ratio is 30% of the sludge fermentation driven short-range denitrification synchronous anaerobic ammonium oxidation reactor 4. The sponge filler provides a growth attachment point for anaerobic ammonium oxidizing bacteria. 4 + -N and NO 2 - With the continuous supply of -N, anaerobic ammonium oxidizing bacteria can grow.

[0047] Step S32: When the effluent ammonia nitrogen concentration NH 4 + -N<1mg / L, total nitrogen removal rate is higher than 90% and maintained for more than 15 days, the in-situ fermentation of residual sludge and the coupling of short-range denitrification / anaerobic ammonium oxidation are completed. The flocculent sludge and sponge filler are taken out, and the anaerobic ammonium oxidation related genes are tested by qPCR. When the copy number of anaerobic ammonium oxidation gene reaches 10 times the initial level, it means that the self-enrichment of anaerobic ammonium oxidizing bacteria is completed.

[0048] Therefore, the present invention adopts the above-mentioned excess sludge in-situ fermentation-driven anaerobic ammonium oxidation self-enrichment device and method, uses the carbon source produced by the excess sludge fermentation as an electron donor to drive the short-term denitrification / anaerobic ammonium oxidation reaction, realizes the resource utilization of excess sludge without the need for an external carbon source, and uses sponge filler as a carrier for in-situ self-enrichment of anaerobic ammonium oxidizing bacteria to construct an integrated sludge fermentation and synchronous short-term denitrification / anaerobic ammonium oxidation system, which can provide a solution for deep denitrification and sludge reduction of urban sewage, and is of great significance to the realization of sustainable urban domestic sewage treatment.

[0049] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solution of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of the present invention.

Claims

1. A device for self-enrichment of anaerobic ammonium oxidation driven by in-situ fermentation of excess sludge, characterized in that: It includes a raw water tank, a full-process nitrification reactor, an intermediate water tank, a sludge fermentation-driven short-term denitrification synchronous anaerobic ammonium oxidation reactor, and a water outlet barrel; the raw water tank and the full-process nitrification reactor, the full-process nitrification reactor and the intermediate water tank, the intermediate water tank and the sludge fermentation-driven short-term denitrification synchronous anaerobic ammonium oxidation reactor, and the sludge fermentation-driven short-term denitrification synchronous anaerobic ammonium oxidation reactor and the water outlet barrel are connected respectively through the raw water tank inlet pump, the full-process nitrification reactor outlet pump, the intermediate water tank outlet pump, and the reactor outlet pump.

2. The excess sludge in-situ fermentation driven anaerobic ammonium oxidation self-enrichment device according to claim 1, characterized in that: The full-process nitrification reactor is set to be open, with a first water inlet at the top of the side close to the raw water tank, a full-process nitrification reactor mud outlet at the bottom of the side close to the raw water tank, and a first water outlet at the middle of the side close to the intermediate water tank; The first water inlet is connected to the output end of the raw water tank inlet pump, and the first water outlet is connected to the input end of the full-process nitrification reactor outlet pump; the full-process nitrification reactor mud outlet is connected to the mud storage barrel through the full-process nitrification reactor mud pump.

3. The excess sludge in-situ fermentation driven anaerobic ammonium oxidation self-enrichment device according to claim 2, characterized in that: A first pH monitor and a dissolved oxygen monitor are respectively arranged on the first water inlet and the first water outlet inside the full-process nitrification reactor; a first stirrer is arranged at the top of the full-process nitrification reactor, and an aeration plate is arranged at the bottom of the full-process nitrification reactor.

4. The excess sludge in-situ fermentation driven anaerobic ammonium oxidation self-enrichment device according to claim 3, characterized in that: A second water inlet is provided at the middle of the intermediate water tank close to the full-process nitrification reactor, and the second water inlet is connected to the output end of the water outlet pump of the full-process nitrification reactor; a second water outlet is provided at the bottom of the intermediate water tank close to the reactor, and the second water outlet is connected to the input end of the water outlet pump of the intermediate water tank.

5. The excess sludge in-situ fermentation driven anaerobic ammonium oxidation self-enrichment device according to claim 4, characterized in that: The sludge fermentation driven short-range denitrification synchronous anaerobic ammonium oxidation reactor has a double-layer structure, with a water bath heating rod provided on the outer layer and a top cover provided on the inner layer. A second agitator is provided inside the sludge fermentation driven short-range denitrification synchronous anaerobic ammonium oxidation reactor on the top cover; a plurality of sponge filler racks are provided at the bottom of the inner layer of the sludge fermentation driven short-range denitrification synchronous anaerobic ammonium oxidation reactor.

6. The excess sludge in-situ fermentation driven anaerobic ammonium oxidation self-enrichment device according to claim 5, characterized in that: A third water inlet is provided on the top of the inner layer of the sludge fermentation driven short-range denitrification synchronous anaerobic ammonium oxidation reactor close to the intermediate water tank, and the third water inlet is connected to the output end of the water outlet pump of the intermediate water tank; A reactor sludge discharge port is provided at the bottom of the inner layer of the sludge fermentation driven short-range denitrification synchronous anaerobic ammonium oxidation reactor close to the intermediate water tank, and the reactor sludge discharge port is connected to a sludge discharge barrel through a reactor sludge discharge pump.

7. The excess sludge in-situ fermentation driven anaerobic ammonium oxidation self-enrichment device according to claim 6, characterized in that: A mud inlet is provided on the top of the inner layer of the sludge fermentation driven short-range denitrification synchronous anaerobic ammonium oxidation reactor close to the water outlet bucket, and the mud inlet is connected to the mud storage bucket through a mud inlet pump; A third water outlet is provided in the middle of the inner layer of the sludge fermentation driven short-range denitrification synchronous anaerobic ammonium oxidation reactor close to the water outlet bucket, and the third water outlet is connected to the input end of the reactor water outlet pump; The second pH monitor and the ORP monitor are respectively arranged at the bottom of the inner third water inlet and the mud inlet of the sludge fermentation driven short-range denitrification synchronous anaerobic ammonium oxidation reactor.

8. A method for driving anaerobic ammonium oxidation self-enrichment by in-situ fermentation of excess sludge as claimed in claim 7, characterized in that: The following steps are involved: Step S1, starting and stabilizing the whole nitration reactor; Step S11, using urban domestic sewage as raw water, wherein the ammonia nitrogen concentration is 30-60 mg / L, and injecting it into the full-process nitrification reactor through a raw water pump; Step S12, inoculating the activated sludge from the aeration tank of the municipal sewage treatment plant in the whole nitrification reactor, controlling the sludge concentration after the sludge and water are mixed to 2000-5000 mg / L, and regularly discharging the sludge into the sludge storage barrel to control the sludge age to 15-25 days; Among them, each operation cycle of the whole 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 controlled at 2-3mg / L, pH maintained at 6.5-8.5, sedimentation 30min, drainage 5-10min, drainage ratio of 50%-70%; Step S13: When the conversion rate of ammonia nitrogen in the raw water into nitrate nitrogen reaches more than 95% and can be stably maintained for more than 7 days, the whole nitrification reactor operates stably; Step S2, starting short-range denitrification driven by in-situ fermentation of excess sludge; Step S3, realization of self-enrichment of anaerobic ammonium-oxidizing bacteria.

9. The method for anaerobic ammonium oxidation self-enrichment driven by in-situ fermentation of excess sludge according to claim 8, characterized in that: Step S2 specifically includes: Step S21, during the operation of the sludge fermentation driven short-range denitrification synchronous anaerobic ammonium oxidation reactor, the water bath heating at 35±2° C. and the pH value at 8.5-9.0 are always maintained; The activated sludge is inoculated in the sludge fermentation driven short-cut denitrification synchronous anaerobic ammonium oxidation reactor, and the sludge inoculation amount accounts for 60%-80% of the volume of the sludge fermentation driven short-cut denitrification synchronous anaerobic ammonium oxidation reactor; Step S22, after the full nitrification reactor is stably running, the water inlet and outlet of the intermediate water tank are respectively connected to the full nitrification reactor and the sludge fermentation driven short-range denitrification synchronous anaerobic ammonium oxidation reactor, and the supernatant discharged after the precipitation of the full nitrification reactor is stored in the intermediate water tank; a. First, the residual sludge in the sludge storage tank is pumped into the sludge fermentation driven short-range denitrification synchronous anaerobic ammonium oxidation reactor; b. The sludge volume at the beginning of each cycle is 10% of the sludge fermentation driven short-range denitrification synchronous anaerobic ammonium oxidation reactor, and the sludge is fermented in situ; c. Then pump the effluent from the full-process nitrification reactor into the intermediate water tank and continue to stir with anoxic stirring; Among them, the sludge concentration in the sludge fermentation-driven short-range denitrification synchronous anaerobic ammonium oxidation reactor is controlled at 7000-9000 mg / L. The specific operation cycle includes: sludge inlet 5-10 minutes, anoxic stirring 14-18 hours, water inlet 10-15 minutes, anoxic stirring 6-8 hours, sludge and water mixture discharge 15-25 minutes, and drainage ratio 30%-50%; Step S23: When the accumulation of nitrite nitrogen exceeds 10 mg / L after the anoxic stirring and is maintained for more than 15 days, the short-range denitrification driven by the in-situ fermentation of the residual sludge is successfully started.

10. The method for anaerobic ammonium oxidation self-enrichment driven by in-situ fermentation of excess sludge according to claim 9, characterized in that: Step S3 specifically comprises: Step S31, fixing a sponge filler frame in the sludge fermentation driven short-range denitrification synchronous anaerobic ammonium oxidation reactor, wherein the filler filling ratio is 20%-40% of that in the sludge fermentation driven short-range denitrification synchronous anaerobic ammonium oxidation reactor; Step S32: When the effluent ammonia nitrogen concentration of the anaerobic ammonium oxidation reactor driven by sludge fermentation is less than 1 mg / L and the total nitrogen removal rate is higher than 90% and maintained for more than 15 days, the coupling of the in-situ fermentation of the residual sludge and the short-term denitrification / anaerobic ammonium oxidation is completed, and the self-enrichment of the anaerobic ammonium oxidizing bacteria is achieved.

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