CN113023872A - Device and method for realizing domestic sewage denitrification by synchronous shortcut nitrification-denitrification-anaerobic ammonia oxidation coupling denitrification - Google Patents

Abstract

A device and a method for realizing domestic sewage denitrification by synchronous shortcut nitrification-denitrification-anaerobic ammonia oxidation coupling denitrification belong to the field of sewage biological treatment. The device comprises a raw water tank, a synchronous short-cut nitrification and denitrification SBR reactor, a regulating water tank and an anaerobic ammonia oxidation coupling denitrification UASB reactor. Domestic sewage enters the shortcut nitrification reactor, full nitrite effluent is achieved through real-time control, effluent enters the intermediate water tank, then the intermediate effluent and the domestic sewage are mixed in proportion through control and enter the anaerobic ammonia oxidation coupling denitrification reactor, the synergistic reaction of anaerobic ammonia oxidation and denitrification is achieved in the anaerobic ammonia oxidation coupling denitrification reactor, and the effect of denitrification is achieved. The invention improves the total nitrogen removal efficiency by fully utilizing the synergistic effect among microorganisms, and realizes the high-efficiency and energy-saving urban sewage denitrification.

Description

Device and method for realizing domestic sewage denitrification by synchronous shortcut nitrification-denitrification-anaerobic ammonia oxidation coupling denitrification

Technical Field

The invention relates to a device and a method for realizing the denitrification of urban domestic sewage by synchronous shortcut nitrification-denitrification-anaerobic ammonia oxidation coupling denitrification, which belong to the field of sewage biological treatment and are suitable for the denitrification of urban domestic sewage with low C/N ratio.

Background

Human activities generate large amounts of wastewater containing C, N, P and other by-products of various elements, resulting in nitrogen and phosphorus pollution of water bodies. Wherein the nitrogen in the municipal sewage mainly exists in the form of organic nitrogen and ammonia nitrogen, which not only has great threat to human health; meanwhile, water eutrophication can be caused, the ecological environment is damaged, and water resource shortage is caused. The traditional biological treatment technology for nitrifying and denitrifying sewage has the problems of high energy consumption and low denitrification efficiency, and can be solved by using a low-consumption and high-efficiency anaerobic ammonia oxidation process for realizing the sustainable development of wastewater treatment, wherein NO is generated by anaerobic ammonia oxidation reaction₃ ^-N, coupling it with denitrification is a popular choice. The front end of the experiment provides NO for anaerobic ammonia oxidation by using short-cut nitrified effluent₂ ^--N, rear end domestic sewage supply of NH₄ ⁺N and COD are coupled with anaerobic ammonia oxidation by utilizing chemoautotrophic property of denitrifying bacteria, so that the advantages of saving aeration amount and low sludge yield are achieved.

The short-cut nitrification is realized by controlling the traditional nitrification process in the ammoxidation stage in a real-time control mode, namely, in the nitrification process, when the ammoxidation reaction is finished, H is not generated in the system any more⁺The pH change curve can have an inflection point, namely an ammonia nitrogen valley point, which is changed from descending to ascending, so that the pH change in the system can be monitored in real time, the aeration is stopped when the pH curve reaches the ammonia nitrogen valley point, the nitration reaction is controlled at the ammonia oxidation stage, and a substrate NO is provided for the anaerobic ammonia oxidation reaction₂ ^--N. Researches show that the proper addition of COD can promote the synergistic denitrification of the anaerobic ammonia oxidation coupled denitrification, the two bacteria can realize stable coexistence relationship, the two bacteria can synergistically remove the total nitrogen in the system, the removal rate of the total nitrogen in the system is improved, and thus the effluent quality is improved.

Disclosure of Invention

The invention provides a device and a method for realizing denitrification of municipal domestic sewage by synchronous shortcut nitrification-denitrification-anaerobic ammonia oxidation coupling denitrification, aiming at solving the problem of insufficient carbon source in the traditional sewage treatment process, saving energy, reducing consumption and improving the quality of effluent.

1. The device for treating the urban domestic sewage by the synchronous shortcut nitrification-denitrification-anaerobic ammonia oxidation coupling denitrification is characterized in that: the system is provided with a raw water tank (1), a synchronous short-cut nitrification internal source denitrification reactor (2), an intermediate water tank (3) and an anaerobic ammonia oxidation coupling denitrification reactor (4): the raw water tank (1) is provided with a water inlet pump I; the short-cut nitrification SBR reactor (2) is provided with a pH tester (2.1), an aeration device (2.2), a DO tester (2.5), a gas flow meter (2.7), an air pump (2.6), a stirring device (2.8), a drain valve (2.4) and a mud valve (2.3); the middle water tank (3) is provided with a water inlet pump II and a water inlet pump III; the upflow anaerobic ammonia oxidation coupling denitrification UASB reactor (4) is provided with a temperature control device (4.1), a pH/DO tester (4.4), a water outlet pipe (4.6) and a gas collection port (4.7).

The experimental device is connected: the raw water tank (1) is connected with a water inlet of the short-cut nitrification SBR reactor (2) through a water inlet pump I (1.1); the water outlet of the shortcut nitrification reactor ((2) is connected with the intermediate water tank (3) through a drain valve (2.4), the water inlet of the anaerobic ammonia oxidation coupling denitrification reactor (4) is respectively connected with the intermediate water tank (3) and the raw water tank (1) through a water inlet pump II (3.1) and a water inlet pump III (3.2), and the water outlet of the anaerobic ammonia oxidation coupling denitrification UASB reactor (4) is drained through a water outlet pipe (4.6).

2. The experimental steps are as follows:

(1) starting the system:

(1.1) starting of the short-cut nitrification SBR reactor: inoculating short-range nitrification floc sludge, controlling the sludge concentration to be 2500-3000 mg/L, the hydraulic retention time to be 4-5 h, and the sludge age to be 15-20 d; pumping sewage into the reactor from a raw water tank through a peristaltic pump in each period, aerating and stirring for 2-3 hours under low oxygen, controlling the dissolved oxygen in the short-cut nitrification reactor to be 0.5-2.0 mg/L, precipitating and draining water with the water drainage ratio of 50%, and discharging NH in the effluent water of the short-cut nitrification SBR reactor₄ ⁺-N and NO₃ ^--N mass concentration of 5mg/L or less, and NO₂ ^-When the mass concentration of N is more than or equal to 15mg/L and the nitrite accumulation rate is more than or equal to 90%, completing the starting process of the short-cut nitrification SBR reactor, and discharging the discharged water into a regulating water tank;

(1.2) starting up of anaerobic ammonia oxidation UASB reactor: inoculatingCarrying out anaerobic ammonia oxidation on granular sludge, wherein the average grain size of the sludge is 0.3-0.5 mm; the sludge is not actively discharged in the operation process; controlling the temperature in the reactor to be 30 +/-1 ℃ by a temperature control device; ② in the anaerobic ammonia oxidation UASB reactor with the concentration of 15-20 mg/LNH₄ ⁺CL and 20-30 mg/LNaNO₂The prepared simulated wastewater is used for feeding water to enrich and culture anaerobic ammonium oxidation bacteria, the temperature in the reactor is controlled to be 30 +/-1 ℃ by a temperature control device, and the pH is adjusted to be 7-8; controlling the sludge concentration in the reactor after mixing to be 4000-5000 mg/L and the hydraulic retention time to be 150-160 min; when reactor effluent NH₄ ⁺-N and NO₂ ^-When the N concentrations are all less than 5mg/L, the start of the anaerobic ammonia oxidation reactor is considered to be successful;

(2) and (3) starting the running operation after success:

(2.1) domestic sewage enters the short-cut nitrification SBR reactor through the water inlet pump I, AO is started to operate, the short-cut nitrification SBR reactor undergoes five processes of water inlet, reaction, standing, precipitation and water outlet, anaerobic stirring is carried out after water inlet, the reaction time is 30-60 min, organic matters in water are removed, and the organic matters are stored as an internal carbon source; then starting an air pump, carrying out aerobic stirring, controlling the dissolved oxygen to be 0.3-2 mg/L by adjusting a gas flowmeter, and carrying out short-cut nitration reaction for 2-3 h; after stirring, standing and precipitating for 30-60 min, then opening a drain valve, wherein the drain ratio is 50-70%, and sludge age is controlled to be 15-20 d by regularly discharging sludge; NH in the reaction effluent₄ ⁺-N and NO₃ ^-The mass concentration of N is less than or equal to 5mg/L, and the nitrite accumulation rate is greater than or equal to 90%;

(2.2) containing NO₂ ^-The effluent of the-N short-cut nitrification SBR enters an intermediate water tank, and the domestic sewage of the intermediate water tank and the raw water tank is treated according to NO by a water inlet pump II and a water inlet pump III₂ ^—N/NH₄ ⁺Mixing N with the mass concentration ratio of 1-1.32, and pumping the mixed sewage into an anaerobic ammonia oxidation coupling denitrification UASB reactor; the hydraulic retention time is 4-7 h, and active sludge discharge is not performed in the operation process; controlling the temperature in the anaerobic ammonia oxidation coupling denitrification reactor to be 30 +/-1 ℃ by using a temperature control device; NH of inlet water is treated by anaerobic ammonium oxidation bacteria in the reactor₄ ⁺-N and NO₂ ^-Conversion of-N to N₂(ii) a The denitrifying bacteria use COD as electron donor and NO₃ ^-Production of NO by reaction of-N₂ ^-N, further supplying for anaerobic ammoxidation reaction, thereby achieving denitrification; NH in the reaction effluent₄ ⁺-N and NO₂ ^-And the mass concentration of N is less than or equal to 5mg/L, and the effluent is discharged through the overflow of the U-shaped water outlet pipe. (3) The experimental device has the advantages that:

1. the realization of synchronous shortcut nitrification-denitrification coupling is facilitated through the combined real-time control of the hypoxia aeration, a substrate is provided for anaerobic ammonia oxidation, the aeration energy consumption can be saved, and the treatment cost is reduced;

2. by-products of the anaerobic ammoxidation reaction are removed through denitrification, the denitrification efficiency of the system is improved, and the effluent quality is improved;

drawings

FIG. 1 is a schematic view of the apparatus of the present invention.

The main symbols are as follows:

1-water inlet tank 2-semi-short distance nitration SBR reactor 3-intermediate water tank

4-anaerobic ammonia oxidation coupling autotrophic denitrification reactor

1.1-peristaltic pump I2.1-pH determinator

2.2-aeration disc 2.3-mud valve 2.4-drainage valve

2.5-DO determinator 2.6-air pump 2.7-rotameter

2.8-stirring devices

3.1-peristaltic Pump 3.2-peristaltic Pump

4.1-temperature control 4.2-water inlet valve 4.3-peristaltic pump

4.4-pH/DO determinator 4.5-reflux port

4.6-water outlet area 4.7-gas collecting opening

Detailed Description

1. The experimental device is connected: the raw water tank (1) is connected with a water inlet of the short-cut nitrification reactor (2) through a water inlet pump I (1.1); the water outlet of the shortcut nitrification reactor ((2) is connected with the intermediate water tank (3) through a drain valve (2.4), the water inlet of the anaerobic ammonia oxidation coupling denitrification reactor (4) is respectively connected with the intermediate water tank (3) and the raw water tank (1) through a water inlet pump II (3.1) and a water inlet pump III (3.2), and the water outlet of the anaerobic ammonia oxidation coupling denitrification reactor (4) is drained through a water outlet pipe (4.6).

2. The experimental steps are as follows:

(1) starting the system:

(1.1) starting of the short-cut nitrification SBR reactor: inoculating short-range nitrification floc sludge, controlling the sludge concentration to be 2500-3000 mg/L, the hydraulic retention time to be 4-5 h, and the sludge age to be 15-20 d; pumping sewage into the reactor from a raw water tank through a peristaltic pump in each period, aerating and stirring for 2-3 hours under low oxygen, controlling the dissolved oxygen in the short-cut nitrification reactor to be 0.5-2.0 mg/L, precipitating and draining water with the water drainage ratio of 50%, and discharging NH in the effluent water of the short-cut nitrification SBR reactor₄ ⁺-N and NO₃ ^--N mass concentration of 5mg/L or less, and NO₂ ^-When the mass concentration of N is more than or equal to 15mg/L and the nitrite accumulation rate is more than or equal to 90%, completing the starting process of the short-cut nitrification SBR reactor, and discharging the discharged water into a regulating water tank;

(1.2) starting up of anaerobic ammonia oxidation UASB reactor: inoculating anaerobic ammonium oxidation granular sludge, wherein the average grain size of the sludge is 0.3-0.5 mm; the sludge is not actively discharged in the operation process; controlling the temperature in the reactor to be 30 +/-1 ℃ by a temperature control device; ② in the anaerobic ammonia oxidation UASB reactor with the concentration of 15-20 mg/LNH₄ ⁺CL and 20-30 mg/LNaNO₂The prepared simulated wastewater is used for feeding water to enrich and culture anaerobic ammonium oxidation bacteria, the temperature in the reactor is controlled to be 30 +/-1 ℃ by a temperature control device, and the pH is adjusted to be 7-8; controlling the sludge concentration in the reactor after mixing to be 4000-5000 mg/L and the hydraulic retention time to be 150-160 min; when reactor effluent NH₄ ⁺-N and NO₂ ^-When the N concentrations are all less than 5mg/L, the start of the anaerobic ammonia oxidation reactor is considered to be successful;

(2) and (3) starting the running operation after success:

(2.1) the domestic sewage enters the short-cut nitrification SBR reactor through the water inlet pump I, the AO is started to operate, the short-cut nitrification SBR reactor undergoes five processes of water inlet, reaction, standing, precipitation and water outlet, the anaerobic stirring is carried out after the water inlet, and the reaction time is 30-60 min, removing organic matters in the water, and storing the organic matters as an internal carbon source; then starting an air pump, carrying out aerobic stirring, controlling the dissolved oxygen to be 0.3-2 mg/L by adjusting a gas flowmeter, and carrying out short-cut nitration reaction for 2-3 h; after stirring, standing and precipitating for 30-60 min, then opening a drain valve, wherein the drain ratio is 50-70%, and sludge age is controlled to be 15-20 d by regularly discharging sludge; NH in the reaction effluent₄ ⁺-N and NO₃ ^-The mass concentration of N is less than or equal to 5mg/L, and the nitrite accumulation rate is greater than or equal to 90%;

(2.2) containing NO₂ ^-The effluent of the-N short-cut nitrification SBR enters an intermediate water tank, and the domestic sewage of the intermediate water tank and the raw water tank is treated according to NO by a water inlet pump II and a water inlet pump III₂ ^—N/NH₄ ⁺Mixing N with the mass concentration ratio of 1-1.32, and pumping the mixed sewage into an anaerobic ammonia oxidation coupling denitrification UASB reactor; the hydraulic retention time is 4-7 h, and active sludge discharge is not performed in the operation process; controlling the temperature in the anaerobic ammonia oxidation coupling denitrification reactor to be 30 +/-1 ℃ by using a temperature control device; NH of inlet water is treated by anaerobic ammonium oxidation bacteria in the reactor₄ ⁺-N and NO₂ ^-Conversion of-N to N₂(ii) a The denitrifying bacteria use COD as electron donor and NO₃ ^-Production of NO by reaction of-N₂ ^-N, further supplying for anaerobic ammoxidation reaction, thereby achieving denitrification; NH in the reaction effluent₄ ⁺-N and NO₂ ^-And the mass concentration of N is less than or equal to 5mg/L, and the effluent is discharged through the overflow of the U-shaped water outlet pipe.

Claims (2)

1. The device for treating the urban domestic sewage by the synchronous shortcut nitrification-denitrification-anaerobic ammonia oxidation coupling denitrification is characterized in that: the system is provided with a raw water tank (1), a synchronous shortcut nitrification and denitrification SBR reactor (2), an intermediate water tank (3) and an anaerobic ammonia oxidation coupling denitrification UASB reactor (4): the raw water tank (1) is provided with a water inlet pump I; the short-cut nitrification SBR reactor (2) is provided with a pH tester (2.1), an aeration device (2.2), a DO tester (2.5), a gas flow meter (2.7), an air pump (2.6), a stirring device (2.8), a drain valve (2.4) and a mud valve (2.3); the middle water tank (3) is provided with a water inlet pump II and a water inlet pump III; the upflow anaerobic ammonia oxidation coupling denitrification UASB reactor (4) is provided with a temperature control device (4.1), a pH/DO tester (4.4), a water outlet pipe (4.6) and a gas collection port (4.7);

the experimental device is connected: the raw water tank (1) is connected with a water inlet of the short-cut nitrification SBR reactor (2) through a water inlet pump I (1.1); the water outlet of the shortcut nitrification SBR reactor ((2) is connected with the intermediate water tank (3) through a drain valve (2.4), the water inlet of the anaerobic ammonia oxidation coupling denitrification reactor (4) is respectively connected with the intermediate water tank (3) and the raw water tank (1) through a water inlet pump II (3.1) and a water inlet pump III (3.2), and the water outlet of the anaerobic ammonia oxidation coupling denitrification UASB reactor (4) is drained through a water outlet pipe (4.6).

2. Method for applying the device according to claim 1, comprising the steps of:

(1) starting the system:

(1.1) starting of the short-cut nitrification SBR reactor: inoculating short-range nitrification floc sludge, controlling the sludge concentration to be 2500-3000 mg/L, the hydraulic retention time to be 4-5 h, and the sludge age to be 15-20 d; pumping sewage into the reactor from a raw water tank through a peristaltic pump in each period, aerating and stirring for 2-3 hours under low oxygen, controlling the dissolved oxygen in the short-cut nitrification reactor to be 0.5-2.0 mg/L, precipitating and draining water with the water drainage ratio of 50%, and discharging NH in the effluent water of the short-cut nitrification SBR reactor₄ ⁺-N and NO₃ ^--N mass concentration of 5mg/L or less, and NO₂ ^-When the mass concentration of N is more than or equal to 15mg/L and the nitrite accumulation rate is more than or equal to 90%, completing the starting process of the short-cut nitrification SBR reactor, and discharging the discharged water into a regulating water tank;

(1.2) starting up of anaerobic ammonia oxidation UASB reactor: inoculating anaerobic ammonium oxidation granular sludge, wherein the average grain size of the sludge is 0.3-0.5 mm; the sludge is not actively discharged in the operation process; controlling the temperature in the reactor to be 30 +/-1 ℃ by a temperature control device; ② in the anaerobic ammonia oxidation UASB reactor with the concentration of 15-20 mg/LNH₄ ⁺CL and 20-30 mg/LNaNO₂The prepared simulated wastewater is used for feeding water to enrich and culture anaerobic ammonium oxidation bacteria, the temperature in the reactor is controlled to be 30 +/-1 ℃ by a temperature control device, and the pH is adjusted to be 7-8; controlling mixingThe sludge concentration in the post-synthesis reactor is 4000-5000 mg/L, and the hydraulic retention time is 150-160 min; when reactor effluent NH₄ ⁺-N and NO₂ ^-When the N concentrations are all less than 5mg/L, the start of the anaerobic ammonia oxidation reactor is considered to be successful;

(2) and (3) starting the running operation after success:

(2.1) domestic sewage enters the short-cut nitrification SBR reactor through the water inlet pump I, AO is started to operate, the short-cut nitrification SBR reactor undergoes five processes of water inlet, reaction, standing, precipitation and water outlet, anaerobic stirring is carried out after water inlet, the reaction time is 30-60 min, organic matters in water are removed, and the organic matters are stored as an internal carbon source; then starting an air pump, carrying out aerobic stirring, controlling the dissolved oxygen to be 0.3-2 mg/L by adjusting a gas flowmeter, and carrying out short-cut nitration reaction for 2-3 h; after stirring, standing and precipitating for 30-60 min, then opening a drain valve, wherein the drain ratio is 50-70%, and sludge age is controlled to be 15-20 d by regularly discharging sludge; NH in the reaction effluent₄ ⁺-N and NO₃ ^-The mass concentration of N is less than or equal to 5mg/L, and the nitrite accumulation rate is greater than or equal to 90%;

(2.2) containing NO₂ ^-The effluent of the-N short-cut nitrification SBR enters an intermediate water tank, and the domestic sewage of the intermediate water tank and the raw water tank is treated according to NO by a water inlet pump II and a water inlet pump III₂ ^—N/NH₄ ⁺Mixing N with the mass concentration ratio of 1-1.32, and pumping the mixed sewage into an anaerobic ammonia oxidation coupling denitrification UASB reactor; the hydraulic retention time is 4-7 h, and active sludge discharge is not performed in the operation process; controlling the temperature in the anaerobic ammonia oxidation coupling denitrification reactor to be 30 +/-1 ℃ by using a temperature control device; NH of inlet water is treated by anaerobic ammonium oxidation bacteria in the reactor₄ ⁺-N and NO₂ ^-Conversion of-N to N₂(ii) a The denitrifying bacteria use COD as electron donor and NO₃ ^-Production of NO by reaction of-N₂ ^-N, further supplying for anaerobic ammoxidation reaction, thereby achieving denitrification; NH in the reaction effluent₄ ⁺-N and NO₂ ^-And the mass concentration of N is less than or equal to 5mg/L, and the effluent is discharged through the overflow of the U-shaped water outlet pipe.

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