CN111675329A

CN111675329A - Reduce strong greenhouse gas N2Sequencing batch reactor operation method for O discharge

Info

Publication number: CN111675329A
Application number: CN202010506190.XA
Authority: CN
Inventors: 陈洪波; 曾龙; 张俊丰
Original assignee: Xiangtan University
Current assignee: Xiangtan University
Priority date: 2020-06-05
Filing date: 2020-06-05
Publication date: 2020-09-18

Abstract

The invention discloses an operation method of a sequencing batch reactor, which realizes strong greenhouse gas N while ensuring good nitrogen and phosphorus removal effect₂And O, emission reduction. The method specifically comprises the following steps: the sequencing batch reactor comprises seven operation steps of water inlet, pre-precipitation, aeration, stirring, secondary precipitation, water outlet and idling, wherein the water inlet is firstly pre-precipitated, then the aeration and stirring reaction is carried out, and finally the water outlet is idled after the secondary precipitation. On the basis of the traditional anaerobic-aerobic-anoxic sequencing batch denitrification and dephosphorization process, the invention replaces anaerobic stirring with pre-precipitation to realize the release of phosphorus and the removal of organic matters, and develops the process capable of effectively reducing N in biological denitrification₂The sequencing batch reactor operation method for O emission has important significance for realizing greenhouse gas emission reduction in sewage treatment.

Description

Reduce strong greenhouse gas N2Sequencing batch reactor operation method for O discharge

Technical Field

The invention mainly relates to the technical field of environmental protection, in particular to a sequencing batch reactor and N in a sewage treatment process₂And (4) emission reduction of O.

Background

The sewage treatment plant plays an important role in the aspects of water pollution control and water environment quality improvement. However, the biological denitrification process discharges a large amount of strong greenhouse gas N₂O, which can cause the stratosphere to produce positive radiation compulsions and ozone layer depletion, has a global warming potential of 298. In recent years, N discharged from sewage treatment plants₂O steadily increases and becomes a non-negligible N₂And O is an artificial emission source. Thus, N₂O emission reduction is an urgent task faced by the current sewage treatment technology innovation.

A sequencing batch anaerobic-aerobic-anoxic biological nitrogen and phosphorus removal process is a traditional biological nitrogen and phosphorus removal technology. After the sewage enters the reactor, anaerobic stirring is firstly carried out to lead the microorganism to decompose the phosphorus and absorb an external carbon source to synthesize the intracellular polymer polyhydroxyalkanoate. Then, the phosphorus accumulating bacteria decompose the intracellular polymer to excessively absorb phosphate in the aeration stage so as to achieve the purpose of phosphorus removal, and meanwhile, the nitrifying bacteria oxidize ammonia nitrogen into nitrate nitrogen in an aerobic section. And finally, in the anoxic stirring stage, the denitrifying bacteria reduce the nitrate nitrogen into nitrogen and discharge the nitrogen, thereby realizing denitrification. The process is stable and efficient, but a large amount of N is generated in the process operation process₂O。

In recent years, the sequencing batch type multi-stage aerobic-anoxic nitrogen and phosphorus removal process (CN 103466795B) fully exerts the metabolism characteristics of microorganisms in the system, and aims to realize N by improving the operation mode of the traditional sequencing batch type anaerobic-aerobic-anoxic process₂And provides a new idea for O emission reduction. However, the direct aeration without passing through the anaerobic zone after water inflow is liable to cause incomplete phosphorus release and increase system instability, and the direct aeration also causes the nitrification process N₂The production of O in large quantities. In order to solve the defects of the latest technology, a pre-precipitation stage is creatively added in front of an aerobic stage, after water inlet is finished, strict anaerobism is not performed, sludge and sewage containing sufficient external carbon sources are subjected to pre-natural precipitation, phosphorus release can be finished through a local micro-anaerobic environment, organic matters can be slowly absorbed for energy storage, and the phenomenon that a large amount of N is generated due to direct aeration is avoided₂And O. The technology obviously reduces N in the sewage treatment process while ensuring good denitrification and dephosphorization effects₂And (4) discharging O.

The invention provides a method for reducing N₂The method for operating the sequencing batch reactor for O discharge sequentially comprises a water inlet stage, a pre-precipitation phosphorus release and energy storage stage, an aerobic energy storage phosphorus absorption and nitrification stage, an anoxic phosphorus absorption and denitrification stage, a precipitation stage, a water outlet stage and an idle stage, and realizes the strong greenhouse gas N while ensuring good nitrogen and phosphorus removal effect₂And O, emission reduction. The invention realizes nitrogen and phosphorus removal and N on the basis of saving energy consumption₂O reduction, is importantAnd theoretical and practical reference values.

Disclosure of Invention

The invention aims to provide a method for reducing strong greenhouse gas N₂Process for the sequencing batch reactor operation with O bleed. The anaerobic section in the traditional sequencing batch denitrification and dephosphorization system is cancelled, and the pre-precipitation stage is added before the aeration stage, so that the N is reduced while the good nitrogen and phosphorus removal effect is ensured₂And (4) discharging O. The invention relates to N in the sewage biological treatment process₂And the emission reduction of O provides a new idea.

Reduce strong greenhouse gas N₂O-discharging sequencing batch reactor operation method, and N is realized on the basis of realizing good nitrogen and phosphorus removal effect₂O emission reduction, which is characterized in that the method comprises a water inlet stage, a pre-precipitation phosphorus release and energy storage stage, an aerobic energy storage phosphorus absorption and nitrification stage, an anoxic phosphorus absorption and denitrification stage, a precipitation stage, a water outlet stage and an idle stage, wherein the device comprises a water inlet valve (1), a water inlet pipe (2), a sludge discharge valve (3), a sludge discharge pipe (4), an air flow meter (5), an air compressor (6), a water outlet pipe (7), a water outlet valve (8), a sequencing batch reactor (9) and a mechanical stirring device (10), and specifically comprises the following steps: the first step is as follows: and (4) water is fed. The water inlet valve (1) is opened, and the sewage enters the sequencing batch reactor (9) through the water inlet pipe (2). The organic load of inlet water is 270-320 mg COD/L, ammonia nitrogen is 20-40 mg/L, and total phosphorus is 8-13 mg/L. The water inlet time is 5-10 min. The second step is that: pre-precipitating. And (3) closing the water inlet valve (2) after water inlet is finished, and precipitating for 30-60 min. The third step: and (6) aerating. An air compressor (6) is started to carry out aeration, and the flow meter (5) is adjusted to control the air flow to be 0.5-0.6 m³And/min. The aeration time is 100-150 min. The fourth step: and (4) stirring. The air compressor (6) is closed, and the mechanical stirring device (10) is turned on for stirring. The stirring speed is 70-85 r/min, and the stirring time is 90-120 min. The fifth step: and (5) secondary precipitation. The mechanical stirring device (10) is closed, and precipitation is carried out for 30-60 min. And a sixth step: and (6) discharging water. And opening a water outlet valve (8) to discharge the treated sewage through a water outlet pipe (7). After the water drainage is finished, the sludge discharge valve (3) is opened to discharge sludge, so that the sludge concentration is kept to be about 4000 mg/L. Go outThe water time is 5-10 min. The seventh step: and (5) idling. The sludge discharge valve (3) is closed, and the reactor is left idle for 100-200 min.

The innovation of the invention is that:

the traditional anaerobic stirring is replaced by the pre-precipitation before the aeration reaction to realize the local micro anaerobic environment, and the phosphorus-accumulating bacteria finish the anaerobic phosphorus release and partial energy storage in the pre-precipitation stage (compared with the traditional anaerobic stirring stage)>60 min), precipitating for 30-60 min to enable more available external carbon sources to remain at the initial stage of the aerobic stage, and realizing optimal configuration of external carbon sources in the pre-precipitation stage and the aerobic stage. Because the decomposition rate of the microorganisms on the external carbon source is higher than that of the internal carbon source, the denitrification can be more thorough by using more external carbon sources, and less N is generated₂O。

The invention has the advantages that:

(1) can effectively realize N on the premise of ensuring good nitrogen and phosphorus removal effect₂And O, emission reduction.

(2) The operation is simple, and the energy consumption is saved.

(3) An anaerobic section which is difficult to realize technically is eliminated, and the process stability is enhanced.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate an embodiment of the invention and, together with the description, serve to explain the invention and not to limit the invention.

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

Wherein: 1-water inlet valve, 2-water inlet pipe, 3-mud discharging valve, 4-mud discharging pipe, 5-air flow meter, 6-air compressor, 7-water outlet pipe, 8-water outlet valve, 9-sequencing batch reactor and 10-mechanical stirring device.

FIG. 2 total phosphorus concentration in reactor effluent.

Figure 3 reactor effluent ammonia nitrogen concentration.

FIG. 4 typical period of the reactor N₂O discharge rate.

DETAILED DESCRIPTION OF EMBODIMENT (S) OF INVENTION

The invention is further described with reference to specific examples, without limiting the scope of the invention.

Example (b):

adding 1L of simulated domestic sewage into the sequencing batch reactor, feeding water for 5 min, and precipitating for 30min in advance after water feeding is completed. Then aerating for 100 min, stirring for 90 min, performing secondary sedimentation for 30min, discharging water for 5 min and standing for 200 min. Wherein the water quality of the inlet water is as follows: the organic load is about 300 mg COD/L, the ammonia nitrogen is about 30 mg/L, and the total phosphorus is about 10 mg/L.

After stable operation, the average ammonia nitrogen and total phosphorus in the effluent of the reactor are respectively 0.57 and 1.29 mg/L, and the average removal rates of the total nitrogen and the total phosphorus are respectively 82.9 percent and 87.1 percent. Therefore, the operation method has good nitrogen and phosphorus removal effects and stable performance. The invention calculates N in a typical period during the operation process₂The discharge coefficient of O is 3.69 percent, which is lower than 4.10 percent in the sequencing batch multi-stage aerobic-anoxic process (CN 103466795B). Compared with anaerobic-aerobic-anoxic sequencing batch denitrification and dephosphorization process and sequencing batch multistage aerobic-anoxic process N₂The O emissions were reduced by about 30.6% and 10.0%, respectively.

Claims

1. Reduce strong greenhouse gas N₂Method for operating sequencing batch reactor with O discharge to realize N on the premise of realizing good nitrogen and phosphorus removal effect₂O emission reduction, which is characterized in that the method comprises a water inlet stage, a pre-precipitation phosphorus release and energy storage stage, an aerobic energy storage phosphorus absorption and nitrification stage, an anoxic phosphorus absorption and denitrification stage, a precipitation stage, a water outlet stage and an idle stage, and the method specifically comprises the following steps of: the first step is as follows: feeding water, starting a water inlet valve (1), and feeding sewage into a sequencing batch reactor (9) through a water inlet pipe (2); the influent organic load is 270-320 mg COD/L, ammonia nitrogen is 20-40 mg/L, total phosphorus is 8-13 mg/L, and the influent time is 5-10 min; the second step is that: pre-precipitating, and closing the water inlet valve after water inlet is finished(2) Precipitating for 30-60 min; the third step: aerating, turning on the air compressor (6) for aeration, adjusting the flow meter (5) to control the air flow to be 0.5-0.6 m³The aeration time is 100-; the fourth step: stirring, namely closing the air compressor (6), and opening the mechanical stirring device (10) to stir at the stirring speed of 70-85 r/min for 90-120 min; the fifth step: secondary precipitation, closing the mechanical stirring device (10), and precipitating for 30-60 min; and a sixth step: discharging water, opening a water outlet valve (8) to discharge the treated sewage through a water outlet pipe (7), and opening a sludge discharge valve (3) to discharge sludge after the water discharge is finished, so that the sludge concentration is kept about 4000 mg/L, and the water discharging time is 5-10 min; the seventh step: and (5) idling, closing the sludge discharge valve (3), and idling the reactor for 100-200 min.