CN113023871B

CN113023871B - Device and method for synchronously treating domestic sewage and late landfill leachate by virtue of shortcut nitrification-anaerobic ammonia oxidation coupling denitrification process

Info

Publication number: CN113023871B
Application number: CN202110264768.XA
Authority: CN
Inventors: 彭永臻; 赵月茹; 张琼
Original assignee: Beijing University of Technology
Current assignee: Beijing University of Technology
Priority date: 2021-03-11
Filing date: 2021-03-11
Publication date: 2022-09-20
Anticipated expiration: 2041-03-11
Also published as: CN113023871A

Abstract

A device and a method for synchronously treating domestic sewage and advanced landfill leachate by short-cut nitrification-anaerobic ammonia oxidation coupling denitrification belong to the field of biological sewage treatment. The device comprises a raw water tank, a short-cut nitrification reactor, an intermediate water tank and an anaerobic ammonia oxidation coupling denitrification reactor. Domestic sewage enters a short-cut nitrification reactor, short-cut water outlet is realized through the combination of low-oxygen aeration and real-time control, outlet water NO 2-N enters an intermediate water tank, is mixed with part of late-stage landfill leachate and then enters an anaerobic ammonia oxidation coupling denitrification reactor, and the synergistic reaction of anaerobic ammonia oxidation denitrification and denitrification is realized in the anaerobic ammonia oxidation coupling denitrification reactor at the same time, so that the denitrification effect is achieved. The invention realizes the high-efficiency and energy-saving urban sewage denitrification by fully utilizing the synergistic effect among microorganisms.

Description

Device and method for synchronously treating domestic sewage and late-stage landfill leachate by virtue of shortcut nitrification-anaerobic ammonia oxidation coupling denitrification process

Technical Field

The invention relates to a device and a method for realizing synchronous denitrification of municipal domestic sewage and advanced landfill leachate by short-cut nitrification-anaerobic ammonia oxidation coupling denitrification, which belong to the field of biological sewage treatment and are suitable for denitrification of low C/N ratio municipal domestic sewage and high ammonia nitrogen landfill leachate.

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. Along with the rapid development of the industry and the city in China, the total amount of the garbage is continuously increased, the treatment of the garbage leachate is a great difficulty, and the leachate generated by the garbage sanitary landfill is high-concentration organic wastewater which needs to be paid attention to and properly treated. 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 reaction ₃ ^- N, coupling it with denitrification is a common choice. The denitrification is to utilize organic carbon source with NO ₃ ^- -N or NO ₂ ^- -N as an electronThe receptor and anaerobic ammonia oxidation coupling denitrification can realize the denitrification of the wastewater with low carbon-nitrogen ratio. The front end of the experiment provides NO for anaerobic ammonia oxidation by using short-cut nitrified effluent ₂ ^- And the rear end is based on the chemoautotrophic property of denitrifying bacteria, and the coupling of the chemoautotrophic bacteria and anaerobic ammonia oxidation has the advantages of saving aeration quantity and low sludge yield.

The shortcut nitrification is characterized in that the traditional nitrification process is controlled at the ammoxidation stage, and can be realized 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 value change curve can have an inflection point which is changed from descending to ascending, namely an ammonia nitrogen valley point, so that the pH value change in the system can be monitored in real time, when the pH value curve reaches the ammonia nitrogen valley point, the aeration is stopped, the nitrification reaction is controlled at the ammoxidation stage, and a substrate NO is provided for the anaerobic ammoxidation reaction ₂ ^- -N。

The anaerobic ammonia oxidation reaction to be solved effluent contains part of NO ₃ ^- The problem of-N, and some researches show that the addition of proper organic matters is beneficial to promoting the anaerobic ammonia oxidation reaction, so that a thought is provided for coupling anaerobic ammonia oxidation with denitrification. The stable coexistence of autotrophic bacteria and heterotrophic bacteria can be realized by controlling the proper proportion of the substrate and the organic matters in the inlet water, the total nitrogen in the system can be removed by the two types of bacteria in a synergistic manner, the removal rate of the total nitrogen in the system is improved, and the quality of the outlet water is improved.

Disclosure of Invention

The invention provides a device and a method for realizing denitrification of synchronous municipal domestic sewage and advanced landfill leachate by short-cut nitrification-anaerobic ammonia oxidation coupling denitrification, aiming at solving the problem of insufficient carbon source in the traditional sewage treatment process and realizing improvement of effluent quality on the premise of energy conservation and consumption reduction.

1. The device for synchronously treating the municipal domestic sewage and the late landfill leachate by short-cut nitrification-anaerobic ammonia oxidation coupling denitrification is characterized in that: the device is provided with a domestic sewage water tank (1), a short distance nitration reactor (2), a garbage percolate water tank (3), an intermediate water tank (4) and an anaerobic ammonia oxidation coupling denitrification reactor (5): the domestic sewage tank (1) is provided with a first water inlet pump (1.1); the short-range nitration reactor (2) is provided with a pH tester (2.1), an aeration device (2.2), a DO tester (2.5), a gas flowmeter (2.7), an air pump (2.6), a first stirring device (2.8), a first drain valve (2.4) and a sludge discharge valve (2.3); the middle water tank (4) is provided with a third water inlet pump (4.1); the anaerobic ammonia oxidation coupling denitrification reactor (5) is provided with a temperature control device (5.1), a second stirring device (5.2), a pH/DO tester (5.3) and a second drain valve (5.4).

The experimental device is connected: the domestic sewage tank (1) is connected with the water inlet of the short-cut nitrification reactor (2) through a first water inlet pump (1.1); the water outlet of the short-cut nitrification reactor (2) is connected with the intermediate water tank (4) through a first drain valve (2.4); the water inlet of the anaerobic ammonia oxidation coupling denitrification reactor (5) is connected with the intermediate water tank (4) and the waste leachate wastewater tank (3) through a second water inlet pump (3.1) and a third water inlet pump (4.1), the two streams of water enter the anaerobic ammonia oxidation coupling denitrification reactor (5) together, and the two streams of water are discharged through a second water discharge valve (5.4).

2. The experimental steps are as follows:

(1) starting the system:

(1.1) starting up the short-cut nitrification 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 10-15 d; pumping the sewage into the short-cut nitrification reactor from the raw water tank through a peristaltic pump in each period, aerating and stirring the sewage under low oxygen, controlling the dissolved oxygen in the short-cut nitrification reactor to be 0.5-2.0 mg/L, precipitating and draining the water with the water drainage ratio of 50%, and discharging NH in the water discharged from the short-cut nitrification reactor ₄ ⁺ N concentration is less than 5mg/L, and nitrate nitrogen concentration of effluent is less than 5mg/L, NO ₂ ^- When the accumulation rate of N reaches more than 85 percent, finishing the starting process of the short-cut nitrification reactor, and discharging the effluent into a regulating water tank;

(1.2) starting the anaerobic ammonia oxidation coupling denitrification reactor: inoculating anaerobic ammonium oxidation sludge, and not actively discharging sludge in the operation process; controlling the temperature in the anaerobic ammonia oxidation coupling denitrification reactor to be 30 +/-5 ℃ by using a temperature control device; ② NH in anaerobic ammoxidation coupling denitrification reactor ₄ ⁺ -N and NO ₂ ^- Simulation wastewater with-N mass concentrations of 15-20 mg/L and 20-30 mg/L respectively is used as inlet water for domesticationAnaerobic ammonium oxidation sludge is treated, the temperature in the anaerobic ammonium oxidation coupling denitrification reactor is controlled to be 30 +/-5 ℃ through a temperature control device, and the pH is adjusted to be about 7; at the same time, the sludge is not actively discharged, and NH is discharged as the water of the reactor ₄ ⁺ -N and NO ₂ ^- -N concentrations are all less than 5mg/L, and NO ₃ ^- When the N concentrations are all less than 5mg/L, the anaerobic ammonia oxidation coupling denitrification reactor is considered to be started successfully;

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

(2.1) the domestic sewage enters the short-cut nitrification reactor through the first water inlet pump (1.1), the AO is started to operate, and the residual NO in the previous period is treated by using organic matters in the domestic sewage ₂ ^- -N is removed by denitrification with a reaction time of 30 min; then starting an air pump, controlling the dissolved oxygen in the short-cut nitrification reactor to be 0.3-2 mg/L by adjusting a gas flow meter, carrying out short-cut nitrification reaction, standing and precipitating for 30-60 min, then starting a drain valve, wherein the drain ratio is 50%, and the sludge age is controlled to be 10-15 d by regularly discharging sludge;

(2.2) short-cut nitrified effluent enters an intermediate water tank, the garbage percolate wastewater and short-cut nitrified effluent are pumped into an anaerobic ammonia oxidation coupling denitrification reactor through a second water inlet pump (3.1) and a third water inlet pump (4.1), and NH of mixed influent is controlled ₄ ⁺ -N and NO ₂ ^— The mass concentration ratio of N is 1-1.5; 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; NH by anaerobic ammoxidation ₄ ⁺ -N and NO ₂ ^- Conversion of-N to N ₂ (ii) a Denitrifying bacteria utilize NO produced by anaerobic ammonia oxidation reaction ₃ ^- The N and part of organic carbon in the landfill leachate are subjected to denitrification reaction to further remove NO generated by anaerobic ammonia oxidation reaction ₃ ^— N, the COD concentration of the effluent is reduced, and the total nitrogen removal rate of the system is improved; the effluent is discharged through a water outlet valve.

(3) The experimental device has the advantages that:

1. the realization of short-cut nitrification is facilitated by combining the low-oxygen aeration with real-time control, a substrate is provided for anaerobic ammonia oxidation, the aeration energy consumption can be saved, and the treatment cost is reduced;

2. by removing the byproducts of the anaerobic ammonia oxidation reaction through denitrification, the denitrification efficiency of the system is improved, the effluent quality is improved, and the sludge yield is reduced;

3. treating two kinds of waste water simultaneously in one reactor; the synchronous removal of the low ammonia nitrogen wastewater and the high ammonia nitrogen wastewater is realized;

4. the anaerobic ammoxidation reaction and the denitrification reaction are combined by adjusting the concentration of the influent substrate, so that a stable coexistence relationship is achieved.

Drawings

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

The main symbols are as follows:

1-domestic sewage inlet tank 2-short distance nitration SBR reactor 3-landfill leachate inlet tank 4-intermediate water tank

5-anaerobic ammonia oxidation coupling denitrification SBBR reactor

1.1-first water intake pump 2.1-pH tester

2.2-aeration disc 2.3-mud valve 2.4-first drain valve

2.5-DO determinator 2.6-air pump 2.7-rotameter

2.8-first stirring device

3.1-second Water intake Pump

4.1-third Water intake Pump

5.1-temperature control device 5.2-second stirring device 5.3-pH/DO tester

5.4-second Drain valve

Detailed Description

1. The device for synchronously treating the municipal domestic sewage and the late landfill leachate by short-cut nitrification-anaerobic ammonia oxidation coupling denitrification is characterized in that: the system is provided with a domestic sewage water tank (1), a short-cut nitrification reactor (2), a landfill leachate water tank (3), an intermediate water tank (4) and an anaerobic ammonia oxidation coupling denitrification reactor (5): the domestic sewage tank (1) is provided with a first water inlet pump (1.1); the short-cut nitrification reactor (2) is provided with a pH tester (2.1), an aeration device (2.2), a DO tester (2.5), a gas flowmeter (2.7), an air pump (2.6), a first stirring device (2.8), a first drain valve (2.4) and a mud valve (2.3); the middle water tank (4) is provided with a third water inlet pump (4.1); the anaerobic ammonia oxidation coupling denitrification reactor (5) is provided with a temperature control device (5.1), a second stirring device (5.2), a pH/DO tester (5.3) and a second drain valve (5.4).

2. The experimental steps are as follows:

(1) starting the system:

(1.2) starting the anaerobic ammonia oxidation coupling denitrification reactor: inoculating anaerobic ammonium oxidation sludge, and not actively discharging sludge in the operation process; controlling the temperature in the anaerobic ammonia oxidation coupling denitrification reactor to be 30 +/-5 ℃ by using a temperature control device; ② NH in anaerobic ammoxidation coupling denitrification reactor ₄ ⁺ -N and NO ₂ ^- Simulation wastewater with the mass concentration of-N being 15-20 mg/L and 20-30 mg/L respectively is taken as inflow water to domesticate anaerobic ammonia oxidation sludge, the temperature in an anaerobic ammonia oxidation coupling denitrification reactor is controlled to be 30 +/-5 ℃ through a temperature control device, and the pH is adjusted to be about 7; at the same time, the mud is not actively discharged,when reactor effluent NH ₄ ⁺ -N and NO ₂ ^- -N concentrations are all less than 5mg/L, and NO ₃ ^- When the N concentration is less than 5mg/L, the anaerobic ammonia oxidation coupling denitrification reactor is considered to be started successfully;

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

(2.2) short-cut nitrified effluent enters an intermediate water tank, the garbage percolate wastewater and short-cut nitrified effluent are pumped into an anaerobic ammonia oxidation coupling denitrification reactor through a second water inlet pump (3.1) and a third water inlet pump (4.1), and NH mixed with the influent is controlled ₄ ⁺ -N and NO ₂ ^— The mass concentration ratio of N is 1-1.5; 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; NH by anaerobic ammoxidation ₄ ⁺ -N and NO ₂ ^- Conversion of-N to N ₂ (ii) a Denitrifying bacteria utilize NO produced by anaerobic ammonia oxidation reaction ₃ ^- The N and part of organic carbon in the landfill leachate are subjected to denitrification reaction to further remove NO generated by anaerobic ammonia oxidation reaction ₃ ^— N, the COD concentration of the effluent is reduced, and the total nitrogen removal rate of the system is improved; the effluent is discharged through a water outlet valve.

Claims

1. A method for simultaneous treatment of urban domestic sewage and late-stage landfill leachate by short-range nitrification-anammox coupled denitrification. The device used in the method is provided with a domestic sewage water tank (1), a short-range nitrification reactor (2), and a landfill leachate water tank. (3), the intermediate water tank (4), the anammox coupled denitrification reactor (5): the domestic sewage water tank (1) is provided with a first inlet pump (1.1); the short-range nitrification reactor (2) is provided with a pH measurement instrument (2.1), aeration device (2.2), DO meter (2.5), gas flow meter (2.7), air pump (2.6), first stirring device (2.8), first drain valve (2.4) and sludge discharge valve (2.3); the intermediate water tank (4) is provided with a third inlet pump (4.1); the anammox coupled denitrification reactor (5) is provided with a temperature control device (5.1), a second stirring device (5.2), pH /DO meter (5.3) and second drain valve (5.4);

The domestic sewage water tank (1) is connected to the water inlet of the short-range nitrification reactor (2) through the first inlet pump (1.1); the water outlet of the short-range nitrification reactor (2) is connected to the intermediate water tank (4) through the first drain valve (2.4) ; The water inlet of the anammox coupled denitrification reactor (5) connects the intermediate water tank (4) with the landfill leachate wastewater water tank (3) through the second inlet pump (3.1) and the third inlet pump (4.1). The water enters the anammox coupled denitrification reactor (5) together, which is drained through the second drain valve (5.4);

It is characterized in that, comprises the following steps:

1) Start-up of the short-range nitrification reactor: inoculate the short-range nitrification floc sludge, control the sludge concentration to be 2500-3000 mg/L, the hydraulic retention time to be 4-5h, and the sludge age to be 10-15d; The domestic sewage tank is pumped into the short-range nitrification reactor, and the low-oxygen aeration is stirred for 3 to 5 hours. When there is no ammonia nitrogen in the effluent ^{and the accumulation rate of NO2-} _N reaches more than 85%, the start-up process of the short-range nitrification reactor is completed, and the effluent is discharged into the intermediate water tank;

Start-up of the anammox coupled denitrification reactor: Add the anammox sludge to the anammox coupled denitrification reactor, so that the sludge concentration in the anammox coupled denitrification reactor reaches 4000-5000mg /L; add the anammox sponge packing into the anammox coupled denitrification reactor, so that the volume of the anammox sponge packing in the anammox coupled denitrification reactor accounts for the anammox coupled denitrification reactor. 40% to 50% of the effective volume of the denitrification reactor;

2) Runtime adjustment operation:

Add urban sewage into the domestic sewage tank (1), start the first inlet pump (1.1) to pump the urban sewage into the short-range nitrification reactor (2); when the short-range nitrification reactor (2) is running, the sludge age is controlled within 10-20d , anoxic stirring for 20 to 30 minutes per cycle, and then aeration and stirring for 120 to 210 minutes, and the dissolved oxygen concentration in the short-range nitrification reactor (2) is controlled to be 0.3 to 1 mg/L. ~70%, the effluent is discharged into the intermediate water tank (4); the effluent from the adjustment water tank passes through the third inlet pump (4.1) and then enters the integrated anammox coupled denitrification reactor with the landfill leachate. According to the ammonia nitrogen concentration of the landfill leachate, Adjust the pump speed of the second feed water pump (3.1) and the third feed water pump (4.1) so that the NO ₂ ^- -N:NH ₄ ⁺ -N mass of the feed water in the integrated anammox denitrification reactor (5) The concentration ratio is 1.5 to 2.0; when the integrated anammox coupled denitrification reactor (5) is running, the anammox coupled denitrification reactor is always in anoxic stirring state, the drainage ratio is 40% to 50%, and the Active mud removal.