An integrated bacterial cultivation device that replaces carbon source addition

Abstract

The present invention provides an integrated bacteria cultivation device for replacing carbon source addition, which relates to the technical field of sewage treatment. The bacteria cultivation device includes an aerobic zone and its supporting aerobic precipitation and aerobic air extraction, a hypoxic zone and its supporting hypoxic precipitation and hypoxic air extraction, and an anaerobic zone and its supporting anaerobic precipitation and anaerobic air extraction. The bacteria cultivation device is constructed with an integrated structure, and water flow power is provided by aerobic air extraction, hypoxic air extraction, and anaerobic air extraction. First, self-hydraulic circulation flow in each area is realized, and then the overall water flow is realized by combining the liquid level difference in each area. The bacteria cultivation device cultivates dominant carbonizing microorganisms in the aerobic zone, cultivates short-range nitrifying dominant bacteria in the hypoxic zone, and cultivates anaerobic ammonia oxidizing dominant bacteria in the anaerobic zone. These different dominant bacteria can be provided to existing sewage treatment plants for use, thereby enhancing the work efficiency of the corresponding links of their sewage treatment, and helping existing sewage treatment plants maintain green and carbon-reducing operations in a more economical way.

Description

Technical Field

[0001] The present invention relates to the technical field of sewage treatment, and in particular to an integrated bacteria cultivation device that replaces carbon source addition. Background Art

[0002] As ecological protection standards gradually increase, wastewater treatment plant discharge standards are also becoming increasingly stringent. Urban wastewater treatment plant effluent, agricultural drainage, aquaculture wastewater, and lakes and reservoirs in my country generally have low C / N ratios. Traditional nitrification and denitrification processes are the most common denitrification technologies used in urban wastewater treatment plants. However, these processes suffer from drawbacks such as aeration and high carbon source consumption.

[0003] Many wastewater treatment plants rely on excessive carbon addition to ensure consistent discharge compliance when their incoming water has a low C / N ratio. This is an unsustainable operating model: it not only increases wastewater treatment operating costs but also generates large amounts of excess sludge and carbon emissions.

[0004] To address the unsustainable operation of the above-mentioned sewage treatment plants, on the one hand, it is urgent to transform them into a green and low-carbon sewage treatment model, and on the other hand, it is necessary to maintain their continuous operation; while reducing the cost of transformation, continue to meet the existing sewage treatment needs. Summary of the Invention

[0005] To address the problems of the existing technology, the present invention proposes an integrated bacterial cultivation device that replaces the addition of a carbon source, treating sewage by adding bacteria without adding a carbon source or by reducing the amount of carbon source added. The integrated bacterial cultivation device proposed in the present invention is installed next to the biochemical pool of a sewage treatment plant. By regularly cultivating anaerobic ammonia-oxidizing bacteria with a very high abundance, these bacteria are added to the denitrification and denitrification area of ​​the existing sewage treatment plant. Regular replacement and recultivation are then performed to maintain a sufficient abundance of anaerobic ammonia-oxidizing bacteria, ensuring that existing sewage treatment plants can achieve stable and standard emissions year-round without adding or with minimal carbon source addition.

[0006] The bacteria cultivation device includes an aerobic zone and its supporting aerobic precipitation and aerobic oxygen extraction, a hypoxic zone and its supporting hypoxic precipitation and hypoxic oxygen extraction, and an anaerobic zone and its supporting anaerobic precipitation and anaerobic oxygen extraction;

[0007] The aerobic zone includes a first aerobic zone and a second aerobic zone, and the hypoxic zone includes a first hypoxic zone, a second hypoxic zone and a third hypoxic zone;

[0008] The inlet water is set at the inlet of the aerobic pump, and after mixing with the mud-water mixture at the end of the second aerobic zone, it enters the first aerobic zone through the aerobic pump;

[0009] After the complete reaction in the first aerobic zone, the mud-water mixture enters the second aerobic zone under the push flow of the aerobic extraction. After that, part of the mud-water mixture enters the aerobic precipitation, and the other part is used as aerobic extraction water to continue to participate in the aerobic reciprocating cycle reaction, dilute and push the high-concentration water;

[0010] The effluent from aerobic precipitation is divided into distribution water 1 and distribution water 2;

[0011] The water distribution 1 is diverted to the front end of the first low oxygen zone and mixed with a portion of the mud-water mixture at the end of the third low oxygen zone; the mud-water mixture after passing through the first low oxygen zone is lifted to the second low oxygen zone by the low oxygen gas;

[0012] After reacting in the second hypoxic zone, the sludge-water mixture enters the third hypoxic zone for further reaction under the combined flow of hypoxic and anaerobic stripping. At the end of the third hypoxic zone, a portion enters the hypoxic sedimentation for mud-water separation, while the remaining portion enters the first hypoxic zone to continue the short-range nitrification reaction in the hypoxic cycle. A portion of the ammonia nitrogen in water distribution 1 undergoes short-range nitrification in the hypoxic zone. The clear water separated after hypoxic sedimentation contains abundant nitrite, providing ample nitrite for the subsequent anaerobic anammox process.

[0013] The clean water rich in nitrite separated by hypoxic precipitation is discharged as effluent, while the other part enters the front end of the anaerobic zone, is completely mixed with the influent containing a large amount of ammonia nitrogen in the water distribution 2, and then enters the anaerobic zone. After completely reacting with the anaerobic ammonia-oxidizing bacteria, it enters the anaerobic precipitation to achieve mud and water separation.

[0014] After anaerobic sedimentation, the sludge containing small particles of anaerobic ammonium oxidizing bacteria is discharged from the pool as residual sludge and can be sold as seed sludge. The small amount of anaerobic ammonium oxidizing bacteria lost in the clarified effluent is filtered through the anaerobic ammonium oxidizing bacteria filter and then anaerobically stripped to the second low-oxygen zone. The ammonia nitrogen that has not reacted completely in the anaerobic zone continues to participate in the short-range nitrification reaction in the low-oxygen zone.

[0015] The effluent from anaerobic extraction and the effluent from hypoxic extraction are completely mixed at the front end of the second hypoxic zone, and then pass through the second hypoxic zone into the third hypoxic zone.

[0016] As a further improvement of the present invention, the bacteria cultivation device adopts an integrated structure.

[0017] As a further improvement of the present invention, the aerobic air extraction, the hypoxic air extraction, and the anaerobic air extraction provide water flow power for their respective functional areas, and then cooperate with the liquid level difference in each area to achieve the overall hydraulic flow of the bacteria cultivation device.

[0018] As a further improvement of the present invention, the aerobic sedimentation is suspended to ensure that the sludge can all flow back to the water channel at the bottom without power, so that the mud-water mixture in the second aerobic zone passes through the bottom of the aerobic sedimentation to provide water for oxygen extraction and aerobic sedimentation.

[0019] As a further improvement of the present invention, the low-oxygen precipitator is suspended to ensure that the sludge can all flow back to the water channel at the bottom without power, so that the mud-water mixture at the end of the third low-oxygen zone passes through the bottom of the low-oxygen precipitator, and a part of it enters the low-oxygen precipitator, and the other part provides water for the low-oxygen precipitator.

[0020] As a further improvement of the present invention, the aerobic precipitation, the hypoxic precipitation and the anaerobic precipitation are all fed with water by overflow, so as to facilitate setting of water inlet valves, adjusting water inlet volume and stopping production for drainage and maintenance.

[0021] As a further improvement of the present invention, the aerobic precipitation and the hypoxic precipitation both include: a water passage, a water outlet trough and a water outlet pipe; their working method is: the sludge slides down to the water passage arranged at the bottom under the action of gravity, and then is discharged through the water outlet trough; the clarified water is discharged through the water outlet pipe arranged on the liquid surface; the water outlet pipe adopts a porous tube or porous trough structure.

[0022] As a further improvement of the present invention, a suspended filler is added to the anaerobic zone as an attachment carrier for anaerobic ammonia-oxidizing bacteria; and a filter screen for intercepting the suspended filler is provided at the entrance to the anaerobic sedimentation at the end of the anaerobic zone.

[0023] As a further improvement of the present invention, the suspended filler is an MBBR suspended filler.

[0024] As a further improvement of the present invention, the anaerobic ammonia-oxidizing bacteria filter is a red bacteria filter, which is arranged at the end of the outlet pipe of the anaerobic precipitation.

[0025] As a further improvement of the present invention, the volume load of the aerobic zone is not less than 1 kg COD cr / m 3 ·d, DO not less than 1mg / l.

[0026] The difference between the COD at the front end of the aerobic zone and the COD of the aerobic precipitation effluent is preferably selected to be no more than 100 mg / l.

[0027] The volume load of the hypoxic zone does not exceed 1.5kgCOD cr / m 3 ·d, DO does not exceed 1mg / l.

[0028] The molar ratio of nitrite nitrogen returned by anaerobic stripping to ammonia nitrogen in the anaerobic zone influent is controlled between 1:1 and 1:1.5.

[0029] The difference between the ammonia nitrogen at the front end of the hypoxic zone and the ammonia nitrogen in the aerobic precipitation effluent shall not exceed 500 mg / l.

[0030] This invention addresses the unsustainable operational challenges faced by existing sewage treatment plants, such as the high cost of carbon source addition. Specifically, it addresses the technical challenges of achieving anaerobic ammonium oxidation (ANAMMOX) without renovating existing sewage treatment plants, and overcomes the challenges of carbon reduction and in-situ capacity expansion in existing sewage treatment plants. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is a plan view of an integrated bacteria cultivation device for replacing carbon source addition disclosed in the present invention. DETAILED DESCRIPTION

[0032] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the present invention will provide a clear and complete description of the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0033] It should be noted that, unless there is any conflict, the embodiments and features in the embodiments of this application can be combined with each other.

[0034] like Figure 1 As shown, the pretreated organic wastewater containing ammonia and nitrogen is first thoroughly mixed with a portion of the muddy-water mixture from the second aerobic zone that has passed through the aerobic sedimentation system at the front end of the aerobic lift system before being lifted to the first aerobic zone by the aerobic lift system. The muddy-water mixture, which has completely reacted in the first aerobic zone, enters the second aerobic zone under the propulsion of the aerobic lift system. After the muddy-water mixture has completely reacted in the second aerobic zone and passes through the aerobic sedimentation system, a portion of it is thoroughly mixed with the incoming water at the front end of the aerobic lift system, driven by the lifting power of the aerobic lift system. The remaining portion of the muddy-water mixture enters the aerobic sedimentation system, achieving mud-water separation. The separated sludge slides directly into the water channel at the bottom of the aerobic sedimentation system under the action of gravity. The clear water from the clarification and separation flows into the subsequent first hypoxic zone and the front end of the anaerobic zone, respectively.

[0035] Because the aerobic zone has a high volumetric load, nitrification is not conducive to progress in a high-load substrate environment. Therefore, even at high dissolved oxygen levels, carbonization is the primary reaction. Therefore, the aerobic zone and its accompanying aerobic precipitation are designed to further reduce biodegradable organic matter in the incoming water while minimizing the reduction of ammonia nitrogen in the incoming water.

[0036] After the aerobic zone reaction and sedimentation, the effluent enters the first hypoxic zone. It is thoroughly mixed with a portion of the sludge-water mixture from the third hypoxic zone that has passed through the hypoxic precipitator at its front end. After undergoing a complete short-cut nitrification reaction in the first hypoxic zone, it is lifted to the front end of the second hypoxic zone by the hypoxic stripping system. It is then thoroughly mixed with the anaerobic precipitator effluent from the anaerobic stripping system at the front end of the second hypoxic zone. After undergoing a complete short-cut nitrification reaction in the second hypoxic zone, it enters the third hypoxic zone. After undergoing complete short-cut nitrification in the third hypoxic zone, the sludge-water mixture passes through a channel at the bottom of the suspended hypoxic precipitator and enters the front end of the hypoxic precipitator. A portion of the sludge-water mixture, guided by the hypoxic stripping system, enters the front end of the first hypoxic zone, participating in a reciprocating reaction cycle. The remaining portion enters the hypoxic precipitator for sludge-water separation. The sludge separated by the hypoxic precipitator slides directly into the water channel at the bottom of the precipitator under the action of gravity. The clarified effluent is used as the influent for the anaerobic zone, while the remaining portion is discharged as the effluent. Since the first hypoxic zone is aerated with high dissolved oxygen in the aerobic zone, the biodegradable organic matter is basically decomposed, which is not conducive to the growth, metabolism and reproduction of denitrifying bacteria. However, it creates a consistent low-substrate growth and metabolism environment for the microorganisms in the hypoxic zone, which is very conducive to nitrifying bacteria becoming the dominant bacteria. Since the dissolved oxygen controlled by the hypoxic zone is relatively low (no more than 1mg / l), this, to a certain extent, inhibits the full nitrification process, while creating a very favorable growth, metabolism and reproduction environment for short-term nitrification. Therefore, the ammonia nitrogen in the incoming water entering the hypoxic zone can be converted into NO2 in large quantities here. - -N, which will provide sufficient NO2 for the anaerobic ammonia-oxidizing bacteria in the subsequent anaerobic zone - - N source.

[0037] After low oxygen precipitation and clarification, it contains rich NO2 - - A portion of the N effluent enters the front end of the anaerobic zone and is completely mixed with the other inlet water containing ammonia nitrogen from the aerobic sedimentation at the front end of the anaerobic zone. After a complete reaction with the anaerobic ammonia-oxidizing bacteria attached to the suspended filler in the anaerobic zone, it is filtered through the suspended filler interception net, and the mud-water mixture enters the subsequent anaerobic sedimentation to achieve mud-water separation. After the mud-water separation by anaerobic sedimentation, the sludge containing small particles of anaerobic ammonia-oxidizing bacteria is discharged from the pool as residual sludge and used for the addition and supplement of anaerobic ammonia-oxidizing bacteria in the sewage treatment plant as a carbon source. The effluent clarified by anaerobic sedimentation must also pass through the anaerobic ammonia-oxidizing bacteria filter (i.e. Figure 1 After being filtered again by the red bacteria filter in the filter, it can be lifted to the second low oxygen zone by anaerobic extraction.

[0038] The present invention uses a filler method because it is difficult to shut down existing sewage treatment plants for renovation. Therefore, the use of a suspended filler method makes it easier to remove the degraded suspended filler, which was previously placed in the denitrification zone of the existing sewage treatment plant, into independent cages and then regularly distribute it to the denitrification zone. This facilitates the regular removal of the degraded suspended filler containing anaerobic ammonium-oxidizing bacteria from the independent cages and their subsequent placement into the anaerobic zone of the bacteria cultivation device of the present invention, allowing it to continue to adhere, increasing the abundance of anaerobic ammonium-oxidizing bacteria and ensuring that the effluent remains stable and meets discharge standards when it is returned.

[0039] The present invention only utilizes the power provided by three gas stripping devices, namely oxygen stripping, low-oxygen stripping and anaerobic stripping, to achieve self-circulating reciprocating flow in each area, and with the cooperation of the liquid level difference in each area, the hydraulic flow of the entire system can be realized.

[0040] This demonstrates that the present invention, through the systematic treatment described above, can replace the current unsustainable practice of adding a carbon source to ensure stable total nitrogen levels by simply adding anaerobic ammonium-oxidizing bacteria. This provides a new solution for existing sewage treatment plants to achieve sustainable operations with low energy consumption, low costs, and green carbon reduction.

[0041] It should be further pointed out that the present invention injects a portion of the effluent from the aerobic zone and the effluent from the anaerobic zone into the hypoxic zone, and further controls the concentration of the matrix components of ammonia nitrogen and nitrite in the hypoxic zone to maintain a certain level by controlling the injection ratio, so as to promote only short-range nitrification reaction in the hypoxic zone and inhibit denitrification reaction; thereby achieving the effect that in the hypoxic zone, short-range nitrifying bacteria become the dominant bacteria and denitrifying bacteria are eliminated or inhibited.

[0042] Furthermore: Although the present invention adopts aerobic, hypoxic and anaerobic treatment structures as a whole, the improvement of the present invention compared with the sewage treatment method in the prior art is that: through the special system structure design of three-stage sedimentation, combined with the design of different operating parameter control modes, a single dominant bacterial genus is cultivated in different areas; specifically: the present invention cultivates dominant carbonizing microbial genus in the aerobic zone (DO≥1mg / l, ORP≥0), cultivates short-term nitrifying dominant bacterial genus in the hypoxic zone (DO≤1mg / l, ORP≥0), and cultivates anaerobic ammonia oxidation dominant bacterial genus in the anaerobic zone (ORP≤0). These different bacterial genera can be provided to existing sewage treatment plants for use, thereby enhancing the work efficiency of the corresponding links in their sewage treatment, and helping existing sewage treatment plants maintain green and carbon-reducing operations in a more economical way.

Claims

1. An integrated bacterial cultivation device that replaces carbon source addition, characterized in that: The bacteria cultivation device includes an aerobic zone and its supporting aerobic precipitation and aerobic oxygen extraction, a hypoxic zone and its supporting hypoxic precipitation and hypoxic oxygen extraction, and an anaerobic zone and its supporting anaerobic precipitation and anaerobic oxygen extraction; The aerobic zone includes a first aerobic zone and a second aerobic zone, and the hypoxic zone includes a first hypoxic zone, a second hypoxic zone and a third hypoxic zone; After the influent is mixed with the mud-water mixture at the end of the second aerobic zone, it enters the first aerobic zone through aerobic extraction; After the reaction in the first aerobic zone, the mixed liquid enters the second aerobic zone under the push flow of the aerobic extractor for reaction. Part of the mixed liquid enters the aerobic precipitation, and the other part is used as aerobic extractor water to continue to participate in the carbonization reaction of the aerobic cycle. The effluent from aerobic precipitation is divided into distribution water 1 and distribution water 2; The water distribution 1 is diverted to the front end of the first low oxygen zone and mixed with a portion of the mixed liquid at the end of the third low oxygen zone; the mixed liquid after passing through the first low oxygen zone is elevated to the second low oxygen zone by the low oxygen gas; The mixed liquid after the reaction in the second hypoxic zone enters the third hypoxic zone under the combined flow of hypoxic and anaerobic stripping to continue the reaction. Part of the mixed liquid at the end of the third hypoxic zone enters the hypoxic sedimentation for mud-water separation, and the other part enters the first hypoxic zone to continue participating in the short-range nitrification reaction of the hypoxic cycle. After low-oxygen precipitation and separation, a portion of the clean water containing nitrite enters the front end of the anaerobic zone, mixes with the water 2, and then enters the anaerobic zone to undergo anaerobic ammonia oxidation reaction through anaerobic ammonia-oxidizing bacteria, and then enters anaerobic precipitation; the other remaining clean water needs to be discharged; After anaerobic sedimentation, the sludge containing anaerobic ammonia-oxidizing bacteria is obtained by separation of mud and water, which is discharged from the pool as a substitute for the external carbon source of the sewage treatment plant. The clarified effluent rich in ammonia nitrogen after being filtered by the anaerobic ammonia-oxidizing bacteria filter is lifted to the second low-oxygen zone through anaerobic air extraction and mixed with the low-oxygen extraction effluent.

2. The bacteria cultivation device according to claim 1, characterized in that The bacteria cultivation device adopts an integrated structure.

3. The bacteria cultivation device according to claim 1, characterized in that The aerobic stripping, the hypoxic stripping and the anaerobic stripping provide hydraulic circulation power for the aerobic zone, the hypoxic zone and the anaerobic zone respectively, and cooperate with the liquid level difference of each area to realize the overall hydraulic flow of the bacteria cultivation device.

4. The bacteria cultivation device according to claim 1, characterized in that The aerobic sedimentation unit is suspended so that the mud-water mixture in the second aerobic zone passes through the bottom of the aerobic sedimentation unit to provide water for oxygen extraction and aerobic sedimentation.

5. The bacteria cultivation device according to claim 1, characterized in that The low oxygen precipitator is suspended so that the mud-water mixture at the end of the third low oxygen zone passes through the bottom of the low oxygen precipitator, a part of which enters the low oxygen precipitator and the other part provides water for the low oxygen precipitator.

6. The bacteria cultivation device according to claim 1, 4 or 5, characterized in that: The aerobic precipitation, the hypoxic precipitation and the anaerobic precipitation are all filled with water by overflow, and the water inflow is regulated by valves and drainage maintenance is achieved.

7. The bacteria cultivation device according to claim 6, characterized in that: Both the aerobic sedimentation and the hypoxic sedimentation include: a water passage, a water outlet trough and a water outlet pipe; their working method is: the sludge slides down to the water passage arranged at the bottom without power under the action of gravity, and then is discharged through the water outlet trough; the clarified water is discharged through the water outlet pipe arranged at the liquid surface; the water outlet pipe adopts a porous tube or porous trough structure.

8. The bacteria cultivation device according to claim 1, characterized in that Suspended fillers are added into the anaerobic zone as attachment carriers for anaerobic ammonia-oxidizing bacteria; and a filter screen for intercepting the suspended fillers is provided at the entrance to the anaerobic sedimentation at the end of the anaerobic zone.

9. The bacteria cultivation device according to claim 8, characterized in that: The suspended filler is an MBBR suspended filler, and the anaerobic ammonia oxidizing bacteria filter is a red bacteria filter, which is arranged at the end of the outlet pipe of the anaerobic sedimentation.

10. The bacteria cultivation device according to claim 1, characterized in that: The volume load of the aerobic zone is not less than 1kgCOD cr / m 3 ·d, DO is not less than 1mg / l; the difference between the COD at the front end of the aerobic zone and the COD of the aerobic precipitation effluent is preferably not more than 100mg / l; the volume load of the hypoxic zone does not exceed 1.5kgCOD cr / m 3 ·d, DO does not exceed 1mg / l; the molar ratio of nitrite nitrogen returned through anaerobic stripping to ammonia nitrogen in the anaerobic zone influent is controlled between 1:1 and 1:1.5; the difference between ammonia nitrogen at the front end of the hypoxic zone and ammonia nitrogen in the aerobic precipitation effluent does not exceed 500mg / l.

Images