CN110054294B

CN110054294B - Device and method for treating low-carbon-nitrogen-ratio urban domestic sewage by integrated synchronous shortcut nitrification-anaerobic ammonia oxidation coupling shortcut denitrification

Info

Publication number: CN110054294B
Application number: CN201910390321.XA
Authority: CN
Inventors: 彭永臻; 刘燕飞; 李夕耀; 吉建涛
Original assignee: Beijing University of Technology
Current assignee: Beijing University of Technology
Priority date: 2019-05-10
Filing date: 2019-05-10
Publication date: 2021-10-15
Anticipated expiration: 2039-05-10
Also published as: CN110054294A

Abstract

An integrated device and a method for treating low-carbon-nitrogen-ratio urban sewage by synchronous shortcut nitrification-anaerobic ammonia oxidation coupled with shortcut denitrification belong to the technical field of biological sewage treatment. The device comprises a municipal sewage raw water tank, an SBR reactor, a blast aerator and a water outlet tank. The reaction begins, the domestic sewage enters the SBR reactor firstly, the denitrifying bacteria utilize the carbon source in the domestic sewage to supply the residual NO in the last period₃ ^‑By short-cut denitrification to produce NO₂ ^‑-N is synchronized with NH₄ ⁺Removing N by anaerobic ammonia oxidation, storing the rest organic matter by denitrifying bacteria to synthesize PHA, performing hypoxia aeration after the reaction is finished, performing integrated anaerobic ammonia oxidation reaction on a biological membrane, and removing NH₄ ⁺-N, generating small amounts of NO₃ ^‑And N, stirring, and performing endogenous denitrification by the denitrifying bacteria by using the stored PHA. The invention realizes NO in the form of short-cut nitrification and short-cut denitrification₂ ^‑N, COD of urban sewage is efficiently removed by accumulation, organic matters in domestic sewage are fully utilized, an external carbon source is not needed, aeration energy consumption is saved, and deep denitrification is realized.

Description

Device and method for treating low-carbon-nitrogen-ratio urban domestic sewage by integrated synchronous shortcut nitrification-anaerobic ammonia oxidation coupling shortcut denitrification

Technical Field

The invention relates to a device and a method for treating low-carbon-nitrogen-ratio urban domestic sewage by integrated synchronous partial nitrification-anaerobic ammonia oxidation coupling partial denitrification, belonging to the technical field of biological sewage treatment.

Background

Along with the continuous improvement of living standard of people, more and more water bodies become eutrophic, including familiar Dian lake, Taihu lake and the like, and along with the shortage of water resources, the eutrophication problem of the water bodies gets more and more attention, and the denitrification problem becomes a difficult point, particularly, the state has brought a new first-level A effluent standard, and the traditional biological denitrification process has the problems of high aeration amount, additional organic carbon source addition, high capital construction investment, complex process control and the like, so the existing requirements are difficult to meet.

The anaerobic ammonia oxidation technology is a novel biological denitrification process in recent years, namely anaerobic ammonia oxygenThe conversion refers to that ammonia nitrogen is directly oxidized into nitrogen gas by taking nitrite nitrogen as an electron acceptor under the anaerobic or anoxic condition, no additional carbon source is needed in the process, no oxygen is needed, and the main product is N₂And also a small amount of NO₃ ^-The process can save the aeration energy consumption, the multiplication time of the biocenosis bearing the anaerobic ammonia oxidation is more than three weeks, and the residual sludge amount can also be greatly reduced.

The integrated anaerobic ammonia oxidation technology combines the short-cut nitrification technology and the anaerobic ammonia oxidation technology in the same system to perform autotrophic denitrification under the condition of relatively low dissolved oxygen, part of sewage containing ammonia nitrogen is oxidized into nitrite, and the residual ammonia nitrogen and the generated nitrite generate N in a reactor₂Compared with water, has more advantages compared with the traditional nitrification-denitrification process, saves 50 percent of aeration quantity, 100 percent of external carbon source and can reduce more than 100 percent of CO₂The release amount of the sludge is reduced, and the sludge has good development prospect. In addition, further deep denitrification by endogenous short-range denitrification is enhanced, and the total nitrogen concentration of effluent is reduced.

The biofilm is adopted to better retain anaerobic ammonium oxidation bacteria and short-range denitrifying bacteria, an anoxic microenvironment is provided for the anaerobic ammonium oxidation bacteria, short-range nitration reaction is carried out on an aerobic layer, and the anaerobic ammonium oxidation and denitrification reaction is carried out on the anoxic layer, so that the integrated anaerobic ammonium oxidation reaction is favorably realized under the aerobic condition, and the deep denitrification effect is achieved.

Disclosure of Invention

The invention aims to provide a device and a method for treating low-carbon-nitrogen-ratio urban domestic sewage by integrated synchronous partial nitrification-anaerobic ammonia oxidation coupling partial denitrification, so as to realize deep and efficient denitrification of the low-carbon-ratio urban sewage. The invention combines the integrated anaerobic ammonia oxidation technology and the biological biofilm formation, simultaneously couples the endogenous short-cut denitrification, and provides main part for the anaerobic ammonia oxidation by utilizing partial short-cut nitrificationNO of₂ ^-The method has the advantages that the deep denitrification is carried out in the same reactor, the first-class A standard of pollutant discharge of urban sewage plants is reached, the operation is simple, and the occupied area is small.

Device of integration synchronous shortcut nitrification anaerobic ammonium oxidation coupling shortcut denitrification treatment low carbon nitrogen ratio municipal sewage, its characterized in that: comprises a municipal sewage raw water tank (1), an integrated SBR reactor (4), a blast aerator (11) and a water outlet tank (5). Wherein the urban sewage raw water tank (1) is connected with the integrated SBR reactor (4) through a water inlet pump (2), and the treated sewage is discharged to a water outlet tank (5) through a water outlet valve (10) from a water outlet (9) of the integrated SBR reactor (4).

The integrated SBR reactor (4) is internally provided with: water inlet (3), go out water tank (5), delivery port (9), outlet valve (10), agitator (6), DO, pH apparatus (7), arrange mud (sample) valve (8), aeration pump (11), gas flowmeter (12), aeration dish (13), filler support (14), anammox fungus biomembrane plastic packing (15), short distance denitrifying bacterium biomembrane plastic packing (16), DO sensor (17), pH sensor (18), on-line monitoring platform (19): the plastic fillers (15) and (16) are fixed on the filler bracket (14), and the volume filling ratio of the fillers is 20-30%. The material is HDPE (high density polyethylene), the shape is cylindrical, the porosity is more than 90%, the material is hung on the filler bracket (14) by a nylon rope and is uniformly distributed in the integrated SBR reactor (4).

The invention also provides a method for treating the urban sewage with low carbon-nitrogen ratio by integrated synchronous partial nitrification-anaerobic ammonia oxidation coupling partial denitrification, which comprises the following steps:

1) the reactor start-up phase: the integrated SBR reactor (4) is inoculated with returned sludge of a traditional sewage treatment plant, so that the concentration of the sludge in the reactor is 2500-3500 mg/L, and is inoculated with plastic filler with a short-range denitrification biological membrane and plastic filler with an anaerobic ammonia oxidation biological membrane. The filling ratio of the two fillers is 20-30%.

2) Normal operation regulation and control of the reactor:

firstly, the reaction is started, the urban domestic sewage enters the integrated SBR reactor (4) through the water inlet pump (2), and the water inlet is the same as the water inletCarrying out anoxic stirring for 1-1.5 h, controlling the rotating speed of the stirrer (6) to be 75-80 r/min, and controlling DO<0.2mg/L of NO left by denitrifying bacteria in the last cycle by using carbon source in domestic sewage₃ ^-Carrying out short-range denitrification, removing the generated nitrite and the ammonia nitrogen in the raw water synchronously through anaerobic ammoxidation, and simultaneously storing the organic matters into the body by denitrifying bacteria to synthesize the PHA as an internal carbon source.

Secondly, after the reaction is finished, the air pump (11) is started, low-oxygen aeration is carried out through the gas flowmeter (12), dissolved oxygen is controlled to be 0.2-0.5 mg/L, integrated anaerobic ammoxidation reaction (namely synchronous short-cut nitrification anaerobic ammoxidation reaction) is carried out on a biomembrane, ammonia nitrogen in sewage is removed, a small amount of nitrate nitrogen is generated, the reaction time is 4-6 h, the online monitoring platform (19) monitors the change curve of the pH value in the reactor on line through the pH sensor (18), the aeration is stopped in time when the pH value changes to the lowest point, over-aeration is prevented, and the aeration pump (11) is connected with the DO sensor (17) for online monitoring of the dissolved oxygen concentration of the reactor better.

And thirdly, after the aerobic stage is finished, starting the stirrer (6), controlling the rotating speed to be 75-80 r/min, carrying out post-anoxic stirring for 0.5-1 h by using the integrated SBR reactor (4), carrying out denitrification by using the internal carbon source stored in the previous period, and deeply removing part of nitrate nitrogen generated in the aerobic stage.

Fourthly, after the reaction is finished, standing and precipitating for 10min for carrying out mud-water separation, wherein the water drainage ratio is 40-50%, and the supernatant is discharged to a water outlet tank (5) through a water outlet (9) and a water outlet valve (10). One cycle is completed and the next cycle follows. The sludge age of the floc sludge in the reactor is controlled to be 15-20 d by adjusting the amount of discharged excess sludge. The device and the method for treating the urban domestic sewage with the low carbon-nitrogen ratio by the integrated synchronous shortcut nitrification-anaerobic ammonia oxidation coupled with the shortcut denitrification have the advantages that:

1) the invention couples short-cut denitrification, short-cut nitrification and anaerobic ammonia oxidation into a reactor, fully utilizes the limited carbon source in the domestic sewage to realize the deep removal of nitrogen and saves the aeration energy consumption and the external carbon source consumption.

2) The SBR reactor is combined with the biological membrane, so that the mass transfer from outside to inside layer by layer can be realized, aerobic and anoxic/anaerobic micro-environments are sequentially formed on the biological membrane, the better reaction of the short-cut nitrification, the anaerobic ammonia oxidation and the short-cut denitrification is facilitated, the biological membrane is formed by adopting a mode of a filler ball membrane hanging, functional strains can be better retained, the loss of anaerobic ammonia oxidizing bacteria is avoided, and the denitrification effect is weakened.

3) The integrated SBR reactor is adopted, so that the process is simple and flexible, the occupied area is small, and the operation is easy.

4) The experiment is carried out by adopting the urban domestic sewage with low carbon-nitrogen ratio, and a foundation is laid for the anaerobic ammonia oxidation autotrophic denitrification treatment of the mainstream urban domestic sewage in the future.

Drawings

FIG. 1 is a schematic diagram of the process structure for treating low carbon-nitrogen ratio municipal sewage by integrated synchronous partial nitrification-anaerobic ammonia oxidation coupled partial denitrification.

In fig. 1: the system comprises a municipal sewage raw water tank 1, a water inlet pump 2, a water inlet 3, an integrated SBR reactor 4, a water outlet tank 5, a stirrer 6, DO and pH measuring instruments 7, a sludge discharge (sampling) valve 8, a water outlet 9, a water outlet valve 10, a blast aerator 11, a gas flowmeter 12, an aeration disc 13, a filler support 14, an anammox bacteria biomembrane plastic filler 15, a short-range denitrifying bacteria biomembrane plastic filler 16, a DO sensor 17, a pH sensor 18 and an online monitoring platform 19.

FIG. 2 is a schematic view of the process of the present invention.

Detailed Description

The embodiments of the present invention will be described in detail below with reference to the drawings and examples.

The device for treating the urban domestic sewage with the low carbon-nitrogen ratio by integrated synchronous partial nitrification-anaerobic ammonia oxidation coupled short-cut denitrification shown in the figure 1 comprises an urban sewage raw water tank (1), an integrated SBR reactor (4), a blast aerator (11) and a water outlet tank (5). The urban sewage raw water tank (1) is connected with the integrated SBR reactor through a water inlet pump (2), and the treated sewage is discharged to a water outlet tank (5) through a water outlet valve (10) from a water outlet (9) of the integrated reactor (4).

The integrated SBR reactor (4) is internally provided with: water inlet (3), go out water tank (5), delivery port (9), outlet valve (10), agitator (6), DO, pH apparatus (7), arrange mud (sample) valve (8), aeration pump (11), gas flowmeter (12), aeration dish (13), filler support (14), anammox fungus biomembrane plastic packing (15), short distance denitrifying bacterium biomembrane plastic packing (16), DO sensor (17), pH sensor (18), on-line monitoring platform (19): the plastic fillers (15) and (16) are fixed on the filler bracket (14), and the volume filling ratio of the fillers is 20-30%. The material is HDPE (high density polyethylene), the shape is cylindrical, the porosity is more than 90%, the filler support (14) is hung on the filler support by a nylon rope, and the filler support is uniformly distributed in the SBR reactor (4).

The specific operation is as follows:

1) the reactor start-up phase: and inoculating the returned sludge of the traditional sewage treatment plant by the integrated SBR to ensure that the concentration of the sludge in the reactor is 2500-3500 mg/L, and inoculating the plastic filler with the short-range denitrification biomembrane and the plastic filler with the anaerobic ammonia oxidation biomembrane. The filling ratio of the two fillers is 20-30%.

2) Normal operation regulation and control of the reactor:

firstly, the reaction starts, urban domestic sewage enters an integrated SBR reactor (4) through a water inlet pump (2), anoxic stirring is carried out for 1-1.5 hours while water is fed, the rotating speed of a stirrer (6) is controlled to be 75-80 r/min, and DO is controlled<0.2mg/L of NO left by denitrifying bacteria in the last cycle by using carbon source in domestic sewage₃ ^-Carrying out short-range denitrification, removing the generated nitrite and the ammonia nitrogen in the raw water synchronously through anaerobic ammoxidation, and simultaneously storing the organic matters into the body by denitrifying bacteria to synthesize the PHA as an internal carbon source.

Fourthly, after the reaction is finished, standing and precipitating for 10min for carrying out mud-water separation, wherein the water drainage ratio is 40-50%, and the supernatant is discharged to a water outlet tank (5) through a water outlet (9) and a water outlet valve (10). One cycle is completed and the next cycle follows. The sludge age of the floc sludge in the reactor is controlled to be 15-20 d by adjusting the amount of discharged excess sludge. The above experiment was conducted by examining the denitrification and decarbonization performance of the integrated system with respect to the domestic wastewater discharged from residential areas of family members around Beijing university,

the quality of the inlet water during the experiment was as follows:

item	COD	NH₄ ⁺	NO₂ ^-	NO₃ ^-	TN
						Range	120～300	42～75	0～0.36	0～0.54	48～78
Mean value	208	55	0.19	0.25	58

Operating parameters during the experiment:

the effective volume of the integrated SBR reactor (4) is 10L;

and (3) hypoxia stage: 5L of domestic sewage enters, the rotating speed of the stirrer is controlled to be 60-80 r/min, DO is controlled to be less than 0.2mg/L, and the reaction time is 1-1.5 h;

an aerobic stage: aerating for 4-6 h, and controlling DO to be 0.2-0.5 mg/L;

a post-anoxic stirring stage: controlling the rotating speed of the stirrer to be 60-80 r/min, controlling DO to be less than 0.2mg/L, and controlling the reaction time to be 0.5-1 h;

a drainage stage: standing and precipitating for 10min, and draining 5L of water with the drainage ratio of 40-50%.

Under the operation condition, the final water outlet average COD < 35mg/L, NH₄ ⁺-N﹤1mg/L、NO₂ ^--N﹤1mg/L、 NO₃ ^--N < 5mg/L, TN < 7.5mg/L effluent water quality indexes all reach first-level A standard.

The foregoing is a detailed description of the invention that will enable those skilled in the art to better understand and utilize the invention, and it is not to be limited thereby, since various modifications and changes may be made by those skilled in the art without departing from the scope of the invention.

Claims

1. The method for treating the urban sewage with the low carbon-nitrogen ratio by integrated synchronous partial nitrification-anaerobic ammonia oxidation coupling partial denitrification comprises the steps that an adopted device comprises an urban sewage raw water tank (1), an integrated SBR reactor (4), a blast aerator (11) and a water outlet tank (5); wherein the urban sewage raw water tank (1) is connected with the integrated SBR reactor (4) through a water inlet pump (2), and the treated sewage is discharged to a water outlet tank (5) through a water outlet valve (10) from a water outlet (9) of the integrated SBR reactor (4);

the integrated SBR reactor (4) is provided with: water inlet (3), go out water tank (5), delivery port (9), outlet valve (10), agitator (6), DO, pH apparatus (7), mud valve (8), blast aeration machine (11), gas flowmeter (12), aeration dish (13), filler support (14), anammox fungus biomembrane plastic packing (15), short distance denitrifying bacterium biomembrane plastic packing (16), DO sensor (17), pH sensor (18), on-line monitoring platform (19): the anaerobic ammonium oxidation bacteria biomembrane plastic filler (15) and the short-range denitrifying bacteria biomembrane plastic filler (16) are fixed on the filler bracket (14), and the volume filling ratio of the fillers is 20-30%; the shape is cylindrical, the porosity is more than 90%, the nylon ropes are threaded on the filler bracket (14) and are uniformly distributed in the integrated SBR reactor (4);

the method is characterized by comprising the following steps:

1) the reactor start-up phase: inoculating reflux sludge of a traditional sewage treatment plant into the integrated SBR reactor to ensure that the concentration of the sludge in the reactor is 2500-3500 mg/L, and inoculating plastic fillers with a short-range denitrification biological membrane and plastic fillers with an anaerobic ammonia oxidation biological membrane; the filling ratio of the two fillers is 20-30%;

2) normal operation regulation and control of the reactor:

firstly, the reaction starts, urban domestic sewage enters an integrated SBR reactor (4) through a water inlet pump (2), anoxic stirring is carried out for 1-1.5 hours while water is fed, the rotating speed of a stirrer (6) is controlled to be 75-80 r/min, and DO is controlled<0.2mg/L of NO left by denitrifying bacteria in the last cycle by using carbon source in domestic sewage₃ ^-Carrying out short-range denitrification, removing generated nitrite and ammonia nitrogen in raw water synchronously through anaerobic ammoxidation, and simultaneously storing organic matters into a body by denitrifying bacteria to synthesize an internal carbon source PHA;

secondly, after the reaction is finished, starting a blast aerator (11), carrying out low-oxygen aeration through a gas flowmeter (12), controlling the dissolved oxygen at 0.2-0.5 mg/L, carrying out integrated synchronous short-cut nitrification anaerobic ammonia oxidation reaction on a biomembrane, removing ammonia nitrogen in sewage, generating nitrate nitrogen, wherein the reaction time is 4-6 h, an online monitoring platform (19) monitors a pH value change curve in the reactor on line through a pH sensor (18), stopping aeration when the pH value changes to the lowest point, preventing over-aeration, and the blast aerator (11) monitors the dissolved oxygen concentration of the reactor by being connected with a DO sensor (17) on line;

after the aerobic stage is finished, starting a stirrer (6), controlling the rotating speed to be 75-80 r/min, carrying out post-anoxic stirring for 0.5-1 h by using the integrated SBR reactor (4), and carrying out denitrification by using the internal carbon source stored in the previous period to remove part of nitrate nitrogen generated in the aerobic stage;

fourthly, after the reaction is finished, standing and precipitating for 10min for carrying out mud-water separation, wherein the water drainage ratio is 40-50%, and the supernatant is discharged to a water outlet tank (5) through a water outlet (9) and a water outlet valve (10); completing one cycle, followed by the next cycle; the sludge age of the floc sludge in the reactor is controlled to be 15-20 d by adjusting the amount of discharged excess sludge.