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CN-120607323-B - Continuous flow AOA (anaerobic-anoxic-oxic) treatment device and treatment method for rapidly starting shortcut nitrification based on intermittent illumination strategy

CN120607323BCN 120607323 BCN120607323 BCN 120607323BCN-120607323-B

Abstract

The invention discloses a continuous flow AOA treatment device for quickly starting shortcut nitrification based on an intermittent illumination strategy in the technical field of sewage biology, which comprises a sewage raw water tank, an AOA reactor, a sedimentation tank and a side flow reactor. The sewage enters an AOA reactor from a raw water tank, sequentially passes through an anaerobic zone, an aerobic zone and an anoxic zone along the water flow direction, part of sewage flows from the anaerobic zone to a side flow reactor, the anaerobic zone mainly carries out anaerobic phosphorus release and internal carbon source storage processes, the aerobic zone carries out nitrification and aerobic phosphorus absorption, the anoxic zone carries out endogenous denitrification, nitrite oxidizing bacteria are inhibited and ammonia oxidizing bacteria are enriched by adopting intermittent illumination in the side flow reactor, the quick start and long-term stability of the short-range nitrification of the AOA reactor are promoted, the process phosphorus removal efficiency is ensured, the nitrite accumulation rate and the total nitrogen removal rate are both stabilized to be more than 80%, the phosphorus removal efficiency can be more than 95%, and a new technical approach is provided for biological nitrogen and phosphorus removal of high-efficiency sewage.

Inventors

  • MENG QINGAN
  • XIA YAN
  • ZHANG MIAO
  • WU JUN

Assignees

  • 扬州大学

Dates

Publication Date
20260512
Application Date
20250623

Claims (10)

  1. 1. A continuous flow AOA treatment device for rapidly starting shortcut nitrification based on an intermittent illumination strategy, comprising: A water inlet tank (1) for storing domestic sewage to be treated and delivering the domestic sewage to a continuous flow AOA reactor; a continuous flow AOA reactor (2) comprising an anaerobic zone, an aerobic zone and an anoxic zone; In the anaerobic zone, the phosphorus accumulating bacteria and the polysaccharide bacteria absorb organic matters in sewage and convert the organic matters into polyhydroxyalkanoates which are stored in cells to obtain a muddy water mixed solution, and the muddy water mixed solution enters an aerobic zone and a side flow reactor (4); In the aerobic zone, ammonia nitrogen in sewage is oxidized into nitrite nitrogen by ammonia oxidizing bacteria, then nitrite nitrogen is further oxidized into nitrate nitrogen by nitrite oxidizing bacteria, polyhydroxyalkanoate is consumed by phosphorus accumulating bacteria and phosphorus is excessively absorbed by phosphorus accumulating bacteria, the growth of nitrite oxidizing bacteria is inhibited and the enrichment of ammonia oxidizing bacteria is promoted by accurately controlling the illumination intensity, meanwhile, the metabolic activity of phosphorus accumulating bacteria is not influenced, and a sludge-water mixture of the aerobic zone and the side flow reactor (4) enters an anoxic zone; In the anoxic zone, the polyphosphoric acid bacteria and the polysaccharide bacteria utilize the stored polyhydroxyalkanoate as an endogenous carbon source, and the nitrite nitrogen and nitrate nitrogen remained in the sewage are used as electron acceptors to perform endogenous denitrification and dephosphorization reactions so as to complete the deep denitrification and dephosphorization treatment of the domestic sewage; The secondary sedimentation tank (3) is connected with the continuous flow AOA reactor (2) through a water outlet pipe (2-12), the sludge at the bottom flows back to the anaerobic zone, the residual sludge is discharged out of the system at regular intervals, and the treated effluent is discharged normally; And a side flow reactor (4) connected with the anaerobic zone, and the sludge-water mixture is cultured and enriched with short-range nitrifying bacteria by intermittent illumination and aeration and is sent back to the anoxic zone.
  2. 2. The continuous flow AOA treatment device for quickly starting short-cut nitrification based on the intermittent illumination strategy according to claim 1, wherein the continuous flow AOA reactor (2) is sequentially divided into an anaerobic zone, an aerobic zone and an anoxic zone from inlet to outlet, the zones are separated by a plugboard, the zones flow in an overflow mode of the plugboard, stirring devices (2-14) are arranged in the zones, and an aeration assembly is arranged in the aerobic zone.
  3. 3. The continuous flow AOA treatment device for quickly starting short-cut nitrification based on the intermittent illumination strategy according to claim 2, wherein a plurality of cells are respectively arranged in the anaerobic zone, the aerobic zone and the anoxic zone, the cells are separated by plugboards, and adjacent cells are connected in a water passing mode of up-down staggered arrangement.
  4. 4. The continuous flow AOA treatment device based on intermittent illumination strategy fast start shortcut nitrification according to claim 2, wherein the aeration assembly comprises an aeration pump (2-13), the aeration pump (2-13) supplies air to an aeration disc (2-13-2) through an aeration pipe (2-13-1), and the aeration discs (2-13-2) are each provided with a rotameter (2-13-3) for accurately adjusting the aeration amount.
  5. 5. The continuous flow AOA treatment device based on the intermittent illumination strategy for quick start shortcut nitrification according to any one of claims 1 to 4, wherein the sludge in the sludge hopper at the bottom of the secondary sedimentation tank (3) is returned to the anaerobic zone through a sludge return pump (3-1), the residual sludge is periodically discharged out of the system through a residual sludge pipe (3-2), and the effluent water after the treatment of the secondary sedimentation tank (3) is discharged through a water discharge pipe (3-3).
  6. 6. The continuous flow AOA treatment device based on intermittent light strategy fast start-up shortcut nitrification as claimed in any one of claims 1 to 4, wherein said side stream reactor (4) comprises a sludge discharge peristaltic pump (4-1), LED tube (4-2), aeration means (4-3) and stirrer (4-4), and short-cut nitrifying flora is enriched by intermittent light and aeration culture and then returned to the anoxic zone of the continuous flow AOA reactor through the sludge discharge peristaltic pump (4-1).
  7. 7. A continuous flow AOA treatment method for rapid start-up shortcut nitrification based on an intermittent illumination strategy, using the apparatus of any one of claims 1 to 6, comprising the steps of: 1) Starting an AOA process; 2) The start of short-cut nitrification in the side-stream reactor (4); 3) And (3) starting and stabilizing the short-cut nitrification in the AOA reactor.
  8. 8. The intermittent illumination strategy-based rapid start shortcut nitrification-based continuous flow AOA treatment method of claim 7, wherein step 1) specifically comprises: 1-1) transferring the sludge to an AOA reactor, and controlling the initial sludge concentration to be 3000-4500 mg/L; 1-2) gradually rising dissolved oxygen in the aerobic zone, controlling the dissolved oxygen in the range of 0.8-1.5 mg/L, and adopting an online dissolved oxygen probe and an aeration assembly to carry out linkage adjustment; 1-3) the sludge in the secondary sedimentation tank (3) flows back to the anaerobic zone through a peristaltic pump, the reflux ratio is set to be 100%, the hydraulic set residence time is maintained by dynamically adjusting the water inflow and the reflux rate, and meanwhile, the sludge age is controlled to be set time through the settled sludge discharged from the secondary sedimentation tank (3); 1-4) monitoring the water quality of effluent of the secondary sedimentation tank (3) every day, and judging that the AOA process is started successfully when the chemical oxygen demand concentration is stably lower than 50 mg/L, the total phosphorus is lower than 1.0 mg/L, the total nitrogen is lower than 25 mg/L and the continuous set time fluctuation range is smaller than +/-10%.
  9. 9. The continuous flow AOA treatment method for rapid initiation of shortcut nitrification based on an intermittent illumination strategy according to claim 8, wherein step 2) comprises: 2-1) continuously flowing a mud-water mixture LED out of an anaerobic zone of an AOA reactor into a side flow reactor (4), wherein the side flow reactor (4) adopts a light-dark periodical environment to be close to actual day-night alternating illumination frequency, the illumination intensity is accurately controlled by an adjustable LED light source, the illumination intensity is 360-480 mu mol/m < 2 >/s, and the sludge concentration in the side flow reactor (4) is maintained at 3000-4500 mg/L; 2-2) after the mud-water mixture enters a side flow reactor (4), sequentially carrying out anaerobic stirring, aeration for controlling the dissolved oxygen to be 0.5-1.0 mg/L and anoxic stirring, wherein the anaerobic and aerobic stages are carried out under the illumination condition, the metabolic activity of nitrite oxidizing bacteria is inhibited through illumination, the enrichment of ammonia oxidizing bacteria is promoted, phosphorus absorption is realized, the set time is illumination before the anoxic stage, the set time is dark after the anoxic stage, and the endogenous denitrification is carried out by the reinforced phosphorus accumulating bacteria; 2-3) the side flow reactor (4) continuously operates until the accumulation rate of the nitrite in the end of the aerobic phase reaches more than 80 percent, and continuously and stably setting time, namely, the short-cut nitrification starting of the side flow reactor (4) is considered to be initially successful, and the next phase is entered.
  10. 10. The continuous flow AOA treatment method for rapid initiation of shortcut nitrification based on an intermittent light strategy according to claim 9, wherein step 3) comprises: 3-1) after the anoxic stage of the side flow reactor (4) is finished, all the muddy water mixture flows to an anoxic zone of the AOA reactor, the side flow reactor (4) stands until illumination starts, fresh muddy water is extracted from the AOA anaerobic zone again, and a closed loop side flow treatment system is formed; 3-2) reducing the dissolved oxygen concentration in the aerobic zone to 0.8-1.5 mg/L, increasing the sludge age to 20 days through settled sludge discharged from a secondary sedimentation tank (3), carrying functional flora acclimated by a side stream system by muddy water mixed solution which flows back to the anoxic zone, and strengthening the short-range nitrification-denitrification efficiency of a main system, wherein when the nitrite accumulation rate in effluent of the aerobic zone is more than or equal to 80 percent and the set time is stably maintained, the short-range nitrification is considered to be successful; 3-3) in the later period of system operation, the illumination mode in the side flow reactor (4) is switched from an LED lamp to natural illumination, and meanwhile, the starting frequency of the side flow reactor (4) is gradually reduced from one time a day to one time a week so as to maintain the short-cut nitrification performance of the AOA reactor; After the 3-4) AOA reactor runs continuously for a long time, the effluent quality of the secondary sedimentation tank (3) is stabilized within the range that the chemical oxygen demand concentration is less than or equal to 50mg/L, the ammonia nitrogen concentration is less than or equal to 5mg/L, the total nitrogen concentration is less than or equal to 15mg/L, and the total phosphorus concentration is less than or equal to 0.5 mg/L, namely the system is considered to reach a stable state.

Description

Continuous flow AOA (anaerobic-anoxic-oxic) treatment device and treatment method for rapidly starting shortcut nitrification based on intermittent illumination strategy Technical Field The invention relates to the technical field of sewage biology, in particular to a continuous flow AOA treatment device and a treatment method. Background The traditional nitrification/denitrification process is generally adopted by urban sewage treatment plants in China, and has two main core pain points, namely, the first major core pain point is that the high-intensity aeration requirement in the nitrification stage causes high energy consumption, and the second major core pain point is that an exogenous carbon source is required to be added in the denitrification process, so that the operation cost is obviously increased. Compared with the short-cut nitrification and denitrification technology, by controlling the oxidation of ammonia nitrogen in the nitrite nitrogen stage, the carbon source requirement of 40% and the aeration energy consumption of 25% can be saved theoretically, and the short-cut nitrification and denitrification technology has obvious advantages in the aspects of energy conservation and emission reduction. However, how to maintain stable nitrite nitrogen accumulation (i.e., short-cut nitrification) in continuous flow reactors remains a key bottleneck limiting the scale-up of the technology. For this technical challenge, the new anaerobic/aerobic/anoxic (AOA) process presents unique advantages. Compared with the traditional A2O process, the AOA realizes two major breakthroughs through process reconstruction, namely, on one hand, a nitrifying liquid backflow link is omitted, the system complexity is simplified, and on the other hand, the endogenous carbon source is utilized to drive denitrification, so that the problem of carbon source shortage in low carbon nitrogen ratio sewage treatment is effectively relieved. The core of realizing the high-efficiency denitrification of the AOA technology is to accurately regulate and control the microbial community structure, namely selectively inhibit Nitrite Oxidizing Bacteria (NOB) and promote enrichment of Ammonia Oxidizing Bacteria (AOB). The current mainstream regulation and control strategies comprise dissolved oxygen concentration control (0.5-1.5 mg/L), temperature gradient regulation and control (30-35 ℃), cooperative inhibition of Free Ammonia (FA) and Free Nitrous Acid (FNA), dynamic regulation of sludge age (SRT) and the like. In recent years, solar energy has been widely focused as a clean and renewable energy source in the field of wastewater treatment, and applications thereof include processes such as photocatalytic oxidation and photo-assisted biological treatment. However, light may have a significant effect on the microbial community in the sewage treatment system, in particular an inhibitory effect on the metabolic activity of the nitrifying bacteria population. Research shows that the inhibition effect of light on the nitrification process is regulated and controlled by various factors including light source type, light intensity, light duration, spectral characteristics, tolerance difference of microorganism strains and the like. Despite these complications, illumination is still considered a potential shortcut nitrification regulatory means. Compared with the conventional shortcut nitrification implementation mode, the selective inhibition effect is particularly prominent in a continuous flow AOA process, phosphorus accumulating bacteria (PAOs) are used as main functional bacterial groups, the light tolerance of the PAOs is improved by 2-3 orders of magnitude compared with that of nitrifying bacterial groups, and the system can still maintain the phosphorus removal efficiency of more than 90% under the light control condition. The technical characteristics enable light control to be a few technical means capable of synchronously realizing short-range nitrification and biological phosphorus removal enhancement. Aiming at the difficult problem of urban sewage treatment (such as large carbon source addition amount, low starting efficiency, poor water outlet stability and the like) with a low C/N ratio and large water quality fluctuation, the research provides an optimization strategy based on sidestream illumination regulation and control, and realizes efficient and stable deep denitrification and dephosphorization of the low C/N urban sewage in a continuous flow AOA process. Disclosure of Invention Aiming at the defects existing in the prior art, the invention provides a continuous flow AOA treatment device and a treatment method for rapidly starting short-cut nitrification based on an intermittent illumination strategy, which solve the problems that the current continuous flow treatment of domestic sewage with low C/N ratio is insufficient in carbon source, short-cut nitrification is difficult to start, and deep denitrification and dephosphoriz