Low-energy-consumption whole-course nitrifying bacteria continuous flow enrichment device and method

Abstract

The invention provides a low-energy-consumption whole-course nitrifying bacteria continuous flow enrichment device and method, and relates to the technical field of microorganism enrichment, the device comprises a water inlet bucket, a pump pipe and a reactor, the top of the reactor is provided with a dust cap, the upper part is provided with a quartz sand layer serving as an enrichment growth carrier, the lower part is provided with a ceramsite layer, and the bottom is provided with an inclined plate and a reactor water inlet; the reactor main body is an organic glass container. According to the scheme, through the design of the inclined plate and the ceramsite layer, an aeration device is not additionally arranged, dissolved oxygen in inlet water is reduced, a low-dissolved-oxygen and low-ammonia-nitrogen growth environment is continuously provided for whole-course nitrifying bacteria, meanwhile, low-energy-consumption operation is achieved, the actual application requirement is met, and support is provided for whole-course nitrifying bacteria separation and identification and engineering application.

Description

Technical Field

[0001] The invention relates to the technical field of microbial enrichment, and in particular to a low-energy-consumption, full-process nitrifying bacteria continuous flow enrichment device and method. Background Art

[0002] Nitrification (ammonia nitrogen is oxidized to nitrite nitrogen and then to nitrate nitrogen) is the first step of biological denitrification and the core link of sewage biological denitrification process. In order to ensure the smooth progress of nitrification, the traditional sewage treatment process usually requires a large amount of energy supply, such as aeration, stirring, circulation, etc., which leads to huge carbon emissions and high operating costs. In 2015, the discovery of full-process nitrifying bacteria broke people's understanding of traditional nitrification. Compared with traditional ammonia oxidizing microorganisms and nitrite oxidizing bacteria, full-process nitrifying bacteria can complete the two-step nitrification process alone and are easier to grow in systems with limited substrates and dissolved oxygen. In sewage treatment, these characteristics can enable the denitrification system with full-process nitrifying bacteria to reduce aeration energy consumption, greenhouse gas N2O emissions and sludge production, while improving the efficiency of deep denitrification, and has certain practical application potential.

[0003] Based on molecular biology methods, it has been determined that complete ammonia oxidizing bacteria are ubiquitous in natural environments and engineering systems, but the enrichment and separation of complete ammonia oxidizing bacteria remains a challenge. At present, most patent reports on the full-process nitrifying bacteria enrichment device use aeration and other measures to control dissolved oxygen, thereby providing a low dissolved oxygen growth environment for the full-process nitrifying bacteria. For example, the enrichment device disclosed in Chinese Patent No.: CN113651416A uses argon and air aeration, and is also provided with a stirring device; the enrichment device disclosed in Chinese Patent No.: CN206590950U is provided with an aeration disk to achieve the effects of aeration and stirring. Although the above patents have achieved effective enrichment of full-process nitrifying bacteria, there is still a certain amount of energy consumption. The enrichment device and method disclosed in Chinese Patent No.: CN109851065B do not have an aeration device, and circulation replaces the stirring effect, but the device operation mode is a sequential batch type, which is difficult to meet the requirements of large and stable sewage flow in sewage treatment plants in practice. In order to meet actual needs while achieving effective enrichment of nitrifying bacteria throughout the process, it is necessary to design a full-process nitrifying bacteria enrichment device with lower energy consumption and continuous operation. Summary of the invention

[0004] The purpose of the present invention is to overcome the problems existing in the prior art and provide a low-energy consumption full-process nitrifying bacteria continuous flow enrichment device and method, which can continuously provide a low dissolved oxygen and low ammonia nitrogen growth environment for the full-process nitrifying bacteria, while achieving low-energy consumption operation and meeting practical application needs, and provide a method for enriching the full-process nitrifying bacteria using the device, so as to provide support for the separation, identification and engineering application of the full-process nitrifying bacteria.

[0005] In order to achieve the above-mentioned purpose, the first aspect of the present invention provides a low-energy consumption, continuous flow enrichment device for nitrifying bacteria throughout the process, comprising a water inlet bucket, a pump pipe and a reactor. The top of the reactor is equipped with a dust cap, the upper part is provided with a quartz sand layer as a growth carrier of the enriched material, the lower part is provided with a ceramsite layer, the bottom is provided with an inclined plate and a water inlet of the reactor, and the reactor body is a plexiglass container; the pump pipe is equipped with a peristaltic pump, one end of which is connected to the bottom of the reactor through the water inlet of the reactor, and the other end is connected to the water inlet bucket; the reactor is also provided with a feed port and a water outlet.

[0006] Preferably, a water outlet is provided on the reactor above the quartz sand layer, a feed port is provided on the reactor at the bottom of the quartz sand layer, and a water inlet is located at the bottom of the ceramsite layer.

[0007] Preferably, the water outlet is located 4 cm away from the quartz sand layer.

[0008] Preferably, the inclined plate is a plexiglass plate and is inclined at 45 degrees, so that the water flow can fully contact the ceramsite and then be evenly distributed in the entire reactor.

[0009] Preferably, the reactor is 40 cm high, 13 cm in inner diameter and has an effective volume of 2 L.

[0010] Preferably, the dust cap is 3 mm thick, 160 mm high and has an inner diameter of 160 mm.

[0011] Preferably, the device is not provided with an aeration device for reducing dissolved oxygen in the influent water.

[0012] The second aspect of the present invention provides a method for continuous flow enrichment of nitrifying bacteria based on a low-energy consumption continuous flow enrichment device for nitrifying bacteria, comprising the following steps:

[0013] Use a peristaltic pump to pump activated sludge containing full-process nitrifying bacteria into the reactor through the water inlet and feed port, let it stand for 24-48 hours, and repeat the above operation again to complete the inoculation of activated sludge;

[0014] The culture medium pre-stored in the water inlet bucket is continuously fed into the reactor through a peristaltic pump and flows out from the water outlet;

[0015] The peristaltic pump is turned on to keep the device running continuously until the nitrifying bacteria are fully enriched on the surface of the quartz sand layer.

[0016] Preferably, the culture medium uses ammonium nitrogen as a nitrogen source at a concentration of 2.8-5.6 mg / L.

[0017] Preferably, the hydraulic retention time of the reactor is 9.6 hours, and the culture medium replacement time in the water inlet bucket is 40-50 hours.

[0018] The technical solution of the present invention may include the following beneficial effects:

[0019] The technical solution of the present invention continuously provides a low dissolved oxygen and low ammonia nitrogen growth environment for the whole-process nitrifying bacteria, while achieving low energy consumption operation and meeting practical application needs, and provides a method for enriching the whole-process nitrifying bacteria using the device, providing support for the separation, identification and engineering application of the whole-process nitrifying bacteria, and has a simple structure and a simple method. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 : Schematic diagram of the structure of the continuous flow full-process nitrifying bacteria enrichment device;

[0021] Figure 2 :The copy number change of amoA gene of nitrifying bacteria during the whole enrichment process of 90 days;

[0022] In the figure: 1. Reactor; 2. Water inlet bucket; 3. Peristaltic pump; 4. Pump tube; 5. Plexiglas container; 6. Dust cap; 7. Quartz sand layer; 8. Inclined plate; 9. Ceramic aggregate layer; 10. Water inlet; 11. Feeding port; 12. Water outlet. DETAILED DESCRIPTION

[0023] In order to enable those skilled in the art to better understand the technical solutions in this specification, the technical solutions in the embodiments of this specification will be clearly and completely described below in conjunction with the drawings in the embodiments of this specification. Obviously, the described embodiments are only part of the embodiments of this specification, not all of the embodiments. Based on the embodiments in this specification, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of this specification.

[0024] The first aspect of the embodiment of the present invention provides a low-energy consumption, full-process nitrifying bacteria continuous flow enrichment device, comprising a water inlet bucket 2, a pump pipe 4 and a reactor 1. The top of the reactor 1 is equipped with a dust cap 6, the upper part is filled with a quartz sand layer 7 as an enrichment growth carrier, the lower part is filled with a ceramsite layer 9, the bottom is provided with an inclined plate 8 and a reactor water inlet 10, and the reactor 1 main body is a plexiglass container 5; one end of the pump pipe 4 is connected to the bottom of the reactor 1 through the reactor water inlet 10, and the other end is connected to the water inlet bucket 2, the pump pipe 4 is equipped with a peristaltic pump 3, and the other end is placed in the water inlet bucket 2; the reactor is also provided with a feed port 11 and a water outlet 12; the reactor 1 is provided with a water outlet 12 above the quartz sand layer 7, the reactor 1 is provided with a feed port 11 at the bottom of the quartz sand layer 7, the water inlet 10 is located at the bottom of the ceramsite layer 9; the water outlet 12 is located 4 cm away from the quartz sand layer.

[0025] The reactor body is a plexiglass container with a dust cap on the top. The upper part is filled with quartz sand as a carrier for the growth of the enriched material, and the lower part is filled with ceramsite as a support to prevent the quartz sand from carrying microorganisms out. At the same time, the microorganisms attached to the surface of the ceramsite can consume the dissolved oxygen in the incoming water; the bottom of the container is an inclined plate, which can make the water flow fully contact the ceramsite and evenly distribute it to the entire reactor.

[0026] Furthermore, the inclined plate 8 is a plexiglass plate and is set at an angle of 45 degrees, so that the water flow can fully contact the ceramsite and then be evenly distributed in the entire reactor. The reactor 1 is 40 cm high, 13 cm in inner diameter, and has an effective volume of 2 L. The dust cap 6 is 3 mm thick, 160 mm high, and 160 mm in inner diameter.

[0027] Example 1: Construction of the device.

[0028] like Figure 1 As shown in the figure, the main body of the continuous flow full-process nitrifying bacteria enrichment device is a reactor, which is a plexiglass container with a height of 40 cm and an inner diameter of 13 cm. The plexiglass plate at the bottom of the container is tilted at 45°, which can make the culture medium fully contact with the bottom filter material. The inclined plate is filled with ceramsite as a support and prevents the quartz sand from carrying microorganisms and reducing dissolved oxygen; the quartz sand is filled above the ceramsite as a carrier for the growth of the enriched material; before the above two materials are filled into the plexiglass container, they are rinsed with tap water for 3 times; finally, a dust cap is placed on the top. One end of the pump tube rinsed with tap water is connected to the bottom water inlet, and after passing through the peristaltic pump, the other end is connected to a glass tube with sufficient weight and placed in the water inlet bucket to ensure that the pump tube can sink to the bottom when the water inlet bucket is full of culture medium. The reactor is also provided with a water outlet and a feed port, which are located 4 cm above the quartz sand layer and at the bottom of the quartz sand layer, respectively, to ensure that the culture medium is fully in contact with the quartz sand carrier.

[0029] Example 2: Enrichment culture of nitrifying bacteria throughout the process.

[0030] This embodiment provides a method for enriching and culturing full-process nitrifying bacteria using the device provided in Example 1, comprising the following steps:

[0031] Step 1: Regularly add the full-process nitrifying bacteria enrichment culture medium to the aerobic activated sludge cultured in the laboratory for a long time, and culture for a total of 14 days. The sludge growth conditions are: temperature 25-35℃, aeration volume 80L / min. In the environment of continuous aeration and cultivation with ammonia nitrogen, the growth of nitrifying bacteria is promoted. Regularly observe the color and state of the activated sludge to ensure that the color of the activated sludge is brown-yellow and not black. The composition of the culture medium is as follows:

[0032] 0.2mM NH4Cl, 50mg / L KH2PO4, 75mg / L KCl, 50mg / LMgSO4×7H2O, 584mg / LNaCl, 4g / LCaCO3, 1ml / Ltrace elements I; 1ml / Ltrace elements II.

[0033] Trace elements I: 34.4mg / L MnSO4×1H2O; 50mg / L H3BO3; 70mg / L ZnCl2; 72.6mg / LNa2MoO4×2H2O; 20mg / L CuCl2×2H2O; 24mg / LNiCl2×6H2O; 80mg / L CoCl2×6H2O; 1g / LFeSO4×7H2O.

[0034] Trace elements II: 0.5g / LNaOH; 3mg / LNa2SeO3×5H2O; 4mg / LNa2WO4×2H2O.

[0035] Step 2: Put the activated sludge described in step 1 into a 2L beaker, place one end of the pump tube in the beaker, and connect the other end to the water inlet and the feed port in sequence, start the peristaltic pump, and pump the activated sludge containing full-process nitrifying bacteria into the reactor at the maximum speed. After standing for 48 hours, repeat the above operation again to complete the inoculation of activated sludge.

[0036] Step 3: Adjust the speed of the peristaltic pump to make the hydraulic retention time of the reactor 9.6 hours. The culture medium stored in the water inlet bucket is continuously input into the organic glass container through the peristaltic pump and flows out from the water outlet; turn on the peristaltic pump to keep the device running continuously until the nitrifying bacteria are fully enriched on the surface of the quartz sand.

[0037] Test example: Quantitative analysis of the functional genes of the whole-process nitrifying bacteria based on Example 2.

[0038] Step 1: In the first, third and fifth months of the operation of the reactor, take the internal quartz sand into a 50mL centrifuge tube, add pure water to the scale line, shake several times to remove the biofilm, transfer the mixed solution to another centrifuge tube, centrifuge at 10,000 rpm for 5 minutes, pour out the supernatant, add pure water and centrifuge again, repeat the above steps 3 times to obtain the full-process nitrifying bacteria enrichment.

[0039] Step 2: Select the bacterial 16S RNA gene as the internal reference gene, and select the specific primers comamoAAF / comamoASR (the upstream primer is

[0040] comamoAAF:AGGNGAYTGGGAYTTCTGG, downstream primer is

[0041] comamoASR:CCGVACATACATRAAGCCCAT), and commissioned Shanghai Sangon Biotechnology Co., Ltd. to use fluorescent quantitative PCR technology to quantify the amoA gene of the whole nitrifying bacteria. The reaction conditions were: 95℃ pre-denaturation for 3min; 95℃ denaturation for 15s, 60℃ annealing / extension for 30s, for a total of 45 cycles. Finally, the amoA gene copy number of the whole nitrifying bacteria was obtained. Figure 2 As shown, after a total of 90 days of enrichment culture, the number of amoA gene copies of nitrifying bacteria per mg of biofilm increased from 26215.21 copies at the beginning to 170288.16 copies on the 90th day, and the nitrifying bacteria were effectively enriched.

[0042] In summary, the technical solution of the present invention continuously provides a low dissolved oxygen and low ammonia nitrogen growth environment for the whole-process nitrifying bacteria, while achieving low energy consumption operation and meeting practical application needs, and provides a method for enriching the whole-process nitrifying bacteria using the device, providing support for the separation, identification and engineering application of the whole-process nitrifying bacteria, and has a simple structure and a simple method.

[0043] The above are only preferred embodiments of the present invention, and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A low-energy consumption, continuous flow enrichment device for nitrifying bacteria, comprising a water inlet bucket (2), a pump pipe (4) and a reactor (1), characterized in that: The reactor (1) is provided with a dust cap (6) on the top, a quartz sand layer (7) as a growth carrier of the enriched material on the top, a ceramsite layer (9) on the bottom, an inclined plate (8) and a reactor water inlet (10) on the bottom, and the reactor (1) is mainly a plexiglass container (5); a pump pipe (4) is provided with a peristaltic pump (3), one end of which is connected to the bottom of the reactor (1) through the reactor water inlet (10), and the other end of which is connected to the water inlet bucket (2); the reactor is also provided with a feed port (11) and a water outlet (12).

2. The device according to claim 1, characterized in that The reactor (1) is provided with a water outlet (12) above the quartz sand layer (7), the reactor (1) is provided with a feed inlet (11) at the bottom of the quartz sand layer (7), and the water inlet (10) is located at the bottom of the ceramsite layer (9).

3. The device according to claim 2, characterized in that The water outlet (12) is located 4 cm away from the quartz sand layer.

4. The device according to claim 1, characterized in that The inclined plate (8) is a plexiglass plate and is arranged at an angle of 45 degrees, so that the water flow can fully contact the ceramsite and then be evenly distributed in the entire reactor.

5. The device according to any one of claims 1 to 4, characterized in that: The reactor (1) has a height of 40 cm, an inner diameter of 13 cm and an effective volume of 2 L.

6. The device according to claim 5, characterized in that The dust cap (6) is 3 mm thick, 160 mm high and has an inner diameter of 160 mm.

7. The device according to claim 6, characterized in that The device is not provided with an aeration device for reducing dissolved oxygen in the influent.

8. A method for continuous flow enrichment of nitrifying bacteria based on the low-energy consumption continuous flow enrichment device for nitrifying bacteria as claimed in any one of claims 1 to 7, characterized in that: The following steps are involved: Using a peristaltic pump (3), pump activated sludge containing full-process nitrifying bacteria into the reactor (1) through the water inlet (10) and the feed port (11), and after standing for 24-48 hours, repeat the above operation again to complete the inoculation of activated sludge; The culture medium pre-stored in the water inlet bucket (2) is continuously fed into the reactor (1) through the peristaltic pump (3) and flows out from the water outlet (12); The peristaltic pump (3) is turned on to maintain the continuous operation of the device until the nitrifying bacteria are fully enriched on the surface of the quartz sand layer (7).

9. The method according to claim 8, characterized in that The culture medium uses ammonium nitrogen as a nitrogen source with a concentration of 2.8-5.6 mg / L.

10. The method according to claim 8 or 9, characterized in that: The hydraulic retention time of the reactor (1) is 9.6 hours, and the culture medium replacement time in the water inlet bucket (2) is 40-50 hours.

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