Anaerobic ammonium oxidation bacteria, short-cut nitrifying bacteria and microalgae coupling system and domestication method thereof

Abstract

The invention relates to the technical field of sewage treatment. The invention discloses an anaerobic ammonium oxidation bacteria, short-cut nitrifying bacteria and microalgae coupling system and a domestication method thereof, which are characterized in that three autotrophic microorganisms with different oxygen requirements are sequentially domesticated by a biological filler according to a sequence of an inner layer, a middle layer and an outer layer to form dissolved oxygen gradient region change. Wherein the microalgae form an oxygen production area in the outer photosynthesis, and the dissolved oxygen concentration in the area is the highest. Short-cut nitrifying bacteria domesticated on the middle-layer biological filler consume oxygen, and the concentration of dissolved oxygen is lower than that of dissolved oxygen in the outer-layer biological filler area. The dissolved oxygen in the inner-layer biological filler area can reach the lowest level, so that the anaerobic ammonium oxidation bacteria can survive suitably, and the stable denitrification of anaerobic ammonium oxidation is ensured. Therefore, the biological membrane obtained by the domestication method provided by the invention is more stable, the mass transfer of the dissolved oxygen is more uniform than that of the traditional mechanical point source aeration, and the influence of the dissolved oxygen on the interior is smaller, so that the treatment effect is more stable. The anaerobic ammonium oxidation bacteria, short-cut nitrifying bacteria and microalgae coupling system does not need aeration, does not need additional organic carbon sources, can absorb CO2 to realize negative emission, is energy-saving and efficient, meets the requirements of dual carbon and green water plant transformation in China, and has important utilization value.

Description

Technical Field

[0001] The present invention relates to the technical field of sewage treatment, and in particular to a coupling system of anaerobic ammonia oxidizing bacteria, short-range nitrifying bacteria and microalgae and a domestication method thereof. Background Art

[0002] Excessive discharge of nitrogen in sewage has greatly aggravated the eutrophication of water bodies and posed a threat to water quality. Nitrogen pollution control has become a global concern. With the continuous improvement of my country's economic level and the continuous improvement of the pipe network system, the types and composition of collected sewage have become more complex. At present, the influent quality of sewage treatment plants generally shows the characteristics of low C / N. Domestic mainstream sewage treatment plants use traditional nitrification and denitrification technology for nitrogen removal, but it has problems such as high energy consumption and large greenhouse gas emissions. In order to meet the future development needs of my country's economy and society, a new type of low-energy and high-efficiency biological denitrification technology is urgently needed.

[0003] Anaerobic ammonium oxidation is an emerging biological denitrification technology that refers to the conversion of NH 4 + -N and NO 2 - -N is converted to N 2 Compared with the traditional nitrification-denitrification process, the anaerobic ammonium oxidation process reduces aeration consumption, organic carbon demand, sludge production and greenhouse gas emissions (N 2 O, etc.). However, since nitrogen in sewage is usually in the form of NH 4 + -N, lacking the substrate NO for anaerobic ammonium oxidation reaction 2 - -N. Usually rely on short-range nitrification to remove part of the NH 4 + -N is oxidized to NO 2 - -N, and then anaerobic ammonium oxidation. However, short-term nitrification still requires a lot of aeration.

[0004] At present, as an autotrophic denitrification technology, the short-cut nitrification-anaerobic ammonium oxidation process greatly reduces the demand for carbon sources and aeration energy consumption, reduces carbon emissions and residual sludge in the denitrification process, and is an emerging process for removing nitrogen from low carbon-nitrogen ratio wastewater with low carbon, low consumption and high efficiency. By utilizing the close ecological relationship between bacteria and algae, such as gas exchange, material circulation and nutrient dependence, the short-cut nitrification-anaerobic ammonium oxidation process is used in a single-stage reactor to achieve efficient and stable autotrophic denitrification. However, how anaerobic ammonium-oxidizing bacteria maintain high activity under the influence of factors such as dissolved oxygen and light still needs to be explored.

[0005] Therefore, developing a coupled system of anaerobic ammonia-oxidizing bacteria, short-range nitrifying bacteria and microalgae to achieve stable operation under non-aerated conditions is of great significance to the development of low-carbon and efficient operation of sewage treatment. Summary of the invention

[0006] In view of this, the present invention proposes a coupling system of anaerobic ammonia oxidizing bacteria, short-term nitrifying bacteria and microalgae and a domestication method thereof. The microalgae in the coupling system produce oxygen under light conditions, while the anaerobic ammonia oxidation process is an anaerobic condition, so it is necessary to use oxygen-consuming short-term nitrifying bacteria as a "bridge" for the cooperation between the two. By adopting a sequential domestication method, microbial anaerobic ammonia oxidizing bacteria, short-term nitrifying bacteria and microalgae with different oxygen requirements are coupled into an integrated denitrification system. The microalgae in the system receive light in the outermost layer, and then provide oxygen to short-term nitrification through photosynthesis. Short-term nitrification can convert NH 4 + -N is oxidized to NO 2 － -N provides reaction matrix for anaerobic ammonium oxidation, and finally anaerobic ammonium oxidation realizes efficient denitrification of sewage. This denitrification system does not require aeration, which greatly reduces aeration energy consumption and treatment costs.

[0007] The technical solution of the present invention is achieved in this way:

[0008] In a first aspect, the present invention provides a method for domesticating a coupled system of anaerobic ammonia-oxidizing bacteria, short-range nitrifying bacteria and microalgae, comprising the following steps:

[0009] S1. constructing a reactor, wherein the reactor comprises a packing frame structure, wherein the packing frame structure comprises two plates arranged in parallel and a connecting support between the two plates;

[0010] The material of the plate is transparent reinforced plastic;

[0011] The connecting struts include inner connecting struts, middle connecting struts and outer connecting struts, which are used to embed and fix the inner biological filler, the middle biological filler and the outer biological filler respectively;

[0012] The reactor is provided with a stirring device, an aeration device and a temperature control device; the reactor is provided with lighting devices around it for vertically illuminating the outer biological filler;

[0013] First, only the inner layer biological filler is embedded on the inner layer connecting pillar;

[0014] S2, prepare NH 4 + -N and NO 2 - -N sewage, and after mixing the anaerobic ammonium oxidation sludge with the sewage, add it into the reactor and start stirring to make the anaerobic ammonium oxidation sludge adhere to and grow on the surface of the inner biological filler; when NH4 + -N and NO 2 - When the reaction is finished, stop stirring, let it stand for 15-30 minutes, then drain the supernatant and add new NH 4 + -N and NO 2 - -N sewage, start stirring again until NH 4 + -N and NO 2 - -N The reaction is completed again, then stop stirring and let stand for 15-30 minutes;

[0015] The above process includes the following mechanisms:

[0016] The stirring causes the anaerobic ammonium oxidation sludge to gradually grow on the inner biological filler. The anaerobic ammonium oxidation bacteria carry out the anaerobic ammonium oxidation denitrification reaction. The chemical reaction equation of the anaerobic ammonium oxidation process is: Can treat NH in sewage 4 + -N and NO 2 - -N to remove.

[0017] S3, repeating step S2 until the anaerobic ammonium oxidation sludge is domesticated, and then embedding the middle-layer biological filler into the middle-layer connecting pillar, so that the middle-layer biological filler completely covers the area on the inner-layer biological filler where the anaerobic ammonium oxidation sludge is attached; 4 + -N sewage is mixed and added into the reactor;

[0018] S4, start aeration and stirring, so that the short-range nitrification sludge adheres to the surface of the middle biological filler, and waits for the NH 4 + After the -N reaction is complete, stop aeration and stirring, let it stand for 15-30 minutes, then drain the supernatant and add new NH 4 + -N sewage, turn on aeration and stirring again until NH 4 + -N The reaction is completed again, then aeration and stirring are stopped and the mixture is allowed to stand for 15-30 minutes;

[0019] The above process includes the following mechanisms:

[0020] Since the anaerobic ammonium oxidation sludge is concentrated on the inner biological filler, the short-cut nitrification sludge mainly grows on the middle biological filler. The middle biological filler and the short-cut nitrification sludge growing on the filler protect the anaerobic ammonium oxidation sludge on the inner biological filler, thus ensuring that the anaerobic ammonium oxidation activity is not affected by dissolved oxygen. The short-cut nitrification sludge uses the dissolved oxygen in the sewage and a part of the NH 4 + -N undergoes a short-range nitrification reaction, i.e., NH 4 + -N is oxidized to NO 2 - -N, the chemical reaction equation is NO generated by short-range nitrification on the middle layer biological filler 2 - -N will enter the inner biological filler and react with NH 4 + -N for anaerobic ammonium oxidation.

[0021] S5, repeating step S4 until the short-range nitrification sludge is tamed, embedding the outer biological filler into the outer connecting pillar, so that the outer biological filler completely covers the area on the middle biological filler where the short-range nitrification sludge is attached; then, placing the microalgae and the NH 4 + -N sewage is mixed and added into the reactor;

[0022] S6. Turn on the lighting and stirring to allow the microalgae to attach and grow on the surface of the outer biological filler. 4 + After the reaction is complete, stop lighting and stirring, let it stand for 15-30 minutes, then drain the supernatant and add new NH 4 + -N sewage, turn on the lighting and stirring again until NH 4 + -N The reaction is completed again, then stop lighting and stirring and let it stand for 15-30 minutes;

[0023] The above process includes the following mechanisms:

[0024] Under light conditions, the microalgae will gradually gather and grow on the outer biological filler due to phototropism. At the same time, the light will first irradiate the outer biological filler. The microalgae on the outermost biological filler will absorb a large amount of light energy for photosynthesis and oxygen production, which also ensures that the middle and inner microorganisms are not affected by light. The microalgae on the outer biological filler absorb a large amount of light energy and produce oxygen through photosynthesis. Therefore, the dissolved oxygen in the area near the outer biological filler is the highest. High dissolved oxygen will transfer to the low dissolved oxygen area. When it is transferred to the area near the middle biological filler, most of the oxygen will be consumed by the short-range nitrifying sludge. The dissolved oxygen transferred to the area near the inner biological filler is very small, so the anaerobic ammonia oxidizing bacteria will not be inhibited by dissolved oxygen and can still maintain activity and utilize NH 4 + -N and NO 2 - -N realizes anaerobic ammonium oxidation denitrification.

[0025] S7. Repeat step S6 until the microalgae domestication is completed.

[0026] In some preferred embodiments, the packing frame structure, the schematic diagram of the biological packing, and the distribution of microorganisms (bacteria or microalgae) in the reactor of the present invention are as follows: Figure 1 The structure and cross section of the packing frame of the present invention are shown in Figure 2 shown.

[0027] The microalgae were successfully domesticated on the outer biological filler, and the system was completed. After the biological denitrification reactor system was successfully constructed, the stirring device and lighting device could be controlled to continuously process the NH 4 + After adding nitrogen-containing sewage to the reactor, turn on the lighting and stirring device, and the algae on the outer biological filler will photosynthesize under the light conditions to produce oxygen, which will be transferred to the middle biological filler to participate in short-range nitrification to convert NH 4 + -N is converted to NO 2 - -N, and finally anaerobic ammonia oxidation is achieved on the inner biological filler to complete the NH 4 + -N denitrification of wastewater. Microalgae photosynthesis requires CO 2 Therefore, the reactor can also achieve CO 2 Negative emissions, and the organic matter produced by photosynthesis can also supply denitrification microorganisms for denitrification, achieving a higher denitrification rate. Therefore, based on the domesticated anaerobic ammonia oxidizing bacteria, short-range nitrifying bacteria and microalgae coupling system of the present invention, the total nitrogen removal rate can reach more than 90%, while also achieving energy saving and consumption reduction and CO 2 Negative emissions.

[0028] In some preferred embodiments, in step S2, the NH 4+ -N and NO 2 - -N sewage, of which NH 4 + -N concentration 80-120mg / L, NH 4 + -N and NO 2 - The molar ratio of -N is 1:1.32.

[0029] In some preferred embodiments, in steps S3-S6, the NH 4 + NH in sewage 4 + -N concentration 80-120mg / L.

[0030] In some preferred embodiments, in step S2, the concentration of the anaerobic ammonium oxidation sludge is 3000-4000 mg / L.

[0031] In some preferred embodiments, in step S3, the concentration of the short-cut nitrification sludge is 1000-2000 mg / L.

[0032] In some preferred embodiments, in step S5, the concentration of the microalgae is 200-500 mg / L.

[0033] NH in sewage 4 + -N and NO 2 - The specific concentration of -N can be adaptively adjusted according to the experimental design and conditions such as sludge, microalgae activity, and specifications.

[0034] In some preferred embodiments, Figure 3 As shown, the thickness of the filling area formed by the inner layer biological filler is the largest, and the thickness of the filling area formed by the outer layer biological filler is the smallest.

[0035] In some preferred embodiments, the thickness ratio of the filling areas respectively formed by the inner layer biological filler, the middle layer biological filler and the outer layer biological filler is 3:2:1.

[0036] The outer biological filler has the smallest thickness in order to control the algae growth area and prevent the internal algae from not being able to receive light, while the inner biological filler has the largest thickness, which helps to form an anaerobic environment for anaerobic ammonia oxidation in the inner biological filler.

[0037] In some preferred embodiments, the stirring speed is 150-250 rpm; the aeration controls the dissolved oxygen in the reactor to be 0.50-0.80 mg / L; the temperature control device controls the reactor temperature to be 25-30°C; the illumination intensity is 250-300 μmol / (s·m 2 ).

[0038] The reactor is an SBR reactor. The size and capacity of the reactor should be reasonably designed according to the experimental scale and the amount of sludge and microalgae added to ensure that there is enough space for biological attachment and growth. The reactor is designed with a convenient drainage and water inlet system to facilitate the discharge of supernatant and the addition of new sewage. The water inlet and drain outlet should be set at appropriate positions of the reactor to avoid interference with biological attachment and growth.

[0039] Necessary monitoring equipment should be installed in the reactor, such as dissolved oxygen sensor, temperature sensor, pH sensor, etc., to monitor the environmental conditions in the reactor in real time. The control system should be able to automatically adjust parameters such as stirring, aeration, and lighting according to the monitoring data to ensure the smooth progress of the acclimation process.

[0040] The above steps involve confirming the NH 4 + -N and NO 2 - -N (or just NH 4 + -N) reaction is complete, and the method comprises:

[0041] 1) Chemical detection method, which measures NH by the color, absorbance or ion peak changes produced by chemical reactions 4 + -N and NO 2 - -N concentration;

[0042] 2) Electrochemical detection method, which uses the current or potential changes generated by the reaction of electrodes with nitrogen compounds to measure their concentration, can achieve real-time monitoring and has high sensitivity.

[0043] Anaerobic ammonium oxidation sludge and short-cut nitrification sludge should come from a stably operating biological treatment system and undergo appropriate pretreatment before use, such as washing and concentration, to remove impurities and improve their activity.

[0044] Microalgae species should be selected that are suitable for sewage treatment, such as Chlorella, Spirulina, etc., and should be purified and amplified before domestication.

[0045] The plates are preferably parallel acrylic organic glass plates, the spacing of which can ensure the embedding and fixation of the biological filler, while ensuring uniform distribution of water flow and gas in the reactor.

[0046] The material of the connecting pillar includes at least one of the following: iron pillar, stainless steel, titanium alloy, aluminum alloy and other metals, carbon fiber composite materials, galvanized steel, cast iron, weathering steel and other alloy materials. The design of the connecting pillar should take into account the weight and stability of the biological filler to ensure that it will not fall off or shift in the reactor.

[0047] The lighting device can provide uniform light intensity, covering the entire outer biological filler area. The lighting device can be an LED white light lamp.

[0048] The temperature control device also includes a temperature sensor installed inside the reactor to monitor the temperature in real time and feed it back to the controller for adjustment.

[0049] In some preferred embodiments, the biological filler is a polyurethane elastic filler with a particle size of 1-4 cm and a cubic shape; the filling degree of the biological filler in the reaction device is 10-30%;

[0050] In some preferred embodiments, the anaerobic ammonium oxidation sludge is reddish brown, granular, and has a denitrification effect of ≥85%. The short-range nitrification sludge is yellowish brown, flocculent, and has a nitrite accumulation rate of ≥90%. The microalgae is Chlorella sorokinensis (available to the public from the Chinese Academy of Sciences Freshwater Algae Seed Bank of the Institute of Hydrobiology, Chinese Academy of Sciences).

[0051] In some preferred embodiments,

[0052] In step S3, the anaerobic ammonium oxidation sludge is acclimated by at least one of the following methods (a1)-(a3):

[0053] (a1) Repeat step S2 until a stable red-brown sludge layer is formed on the surface of the inner biological filler and can be removed after adding sewage.

[0054] NH 4 + -N completely removed;

[0055] (a2) repeating step S2 at least 30 times;

[0056] (a3) repeating step S2 until the total nitrogen removal rate in the sewage is ≥85%;

[0057] In step S5, the short-range nitrification sludge acclimation is completed by at least one of the following methods (b1)-(b3):

[0058] (b1) Repeat step S4 until a stable yellow-brown sludge layer is formed on the surface of the middle biological filler and can be removed after adding sewage.

[0059] NH 4 +-N completely removed;

[0060] (b2) repeating step S4 at least 30 times;

[0061] (b3) repeating step S4 until the total nitrogen removal rate in the sewage is ≥85%;

[0062] In step S7, the microalgae are domesticated by at least one of the following methods (c1)-(c3):

[0063] (c1) Repeat step S6 until a stable green layer forms on the surface of the outer biological filler and the NH4+ can be removed within ≤10 h after the addition of sewage. 4 + -N completely removed;

[0064] (c2) repeating step S6 at least 30 times;

[0065] (c3) Repeat step S6 until the total nitrogen removal rate in the sewage is ≥ 85%.

[0066] In a second aspect, the present invention also provides a coupling system of anaerobic ammonia oxidizing bacteria, short-term nitrifying bacteria and microalgae constructed according to any of the above-mentioned domestication methods, characterized in that the system is used for biological denitrification, and under light conditions, the system does not require aeration and does not require an external organic carbon source, and forms a dissolved oxygen gradient regional change through the outer microalgae oxygen production zone, the middle short-term nitrification oxygen consumption zone and the inner anaerobic ammonia oxidation anaerobic denitrification zone.

[0067] like Figure 4 As shown in the figure, under light conditions, the outer, middle and inner biofillers in the reactor will form a dissolved oxygen gradient zone and achieve NH 4 + -N sewage is effectively removed. The microalgae on the outer biological filler in the reactor will be the first to receive light, absorb light energy to achieve photosynthesis and produce oxygen. At this time, the dissolved oxygen concentration in the outer biological filler is the highest, which will be transferred to the short-range nitrifying bacteria on the middle biological filler. The short-range nitrifying bacteria will use oxygen to achieve a short-range nitrification process, that is, NH 4 + -N is oxidized to NO 2 - -N, the chemical reaction equation of ammonia oxidation process is NO produced by short-term nitrification 2 - -N can provide a reaction matrix for the anaerobic ammonium oxidation in the inner biological filler. At the same time, the short-range nitrifying bacteria on the middle biological filler will consume dissolved oxygen, providing a guarantee for the anaerobic microenvironment required by the anaerobic ammonium oxidizing bacteria on the inner biological filler. Ultimately, the anaerobic ammonium oxidation on the inner biological filler can achieve efficient denitrification of sewage. The chemical reaction equation of the anaerobic ammonium oxidation process is:

[0068]

[0069] The beneficial effects of the present invention include at least the following:

[0070] The anaerobic ammonia oxidizing bacteria, short-range nitrifying bacteria and microalgae coupling system provided by the present invention couples three autotrophic microorganisms with different oxygen requirements, namely anaerobic ammonia oxidizing bacteria, short-range nitrifying bacteria and microalgae. Under light conditions, the outer, middle and inner biological fillers of the reactor will form a dissolved oxygen gradient zone, and achieve NH 4 + -N sewage is effectively removed. In the denitrification process of the coupling system, no aeration equipment is required, and only photosynthesis is required to utilize algae to produce oxygen instead of mechanical aeration, which is more economical and energy-saving.

[0071] In the coupling system provided by the present invention, the microalgae on the outer biological filler can all receive light, and can form a uniform photosynthesis oxygen production zone under sufficient light conditions, which is conducive to the formation of obvious outer biological filler microalgae oxygen production zone, middle biological filler short-range nitrification oxygen consumption zone and inner biological filler anaerobic ammonia oxidation anaerobic denitrification zone.

[0072] In the domestication method provided by the present invention, the three kinds of microorganisms are domesticated in the biological filler in the order of the inner layer, the middle layer and the outer layer, thereby forming a regional change of dissolved oxygen gradient. Microalgae photosynthesize in the outer layer to form an oxygen-producing area, and the dissolved oxygen concentration in this area is the highest. The short-range nitrifying bacteria domesticated on the middle-layer biological filler will consume oxygen, and the dissolved oxygen concentration is lower than that in the outer biological filler area. The dissolved oxygen in the inner biological filler area will reach the lowest level, which is suitable for the survival of anaerobic ammonia-oxidizing bacteria, ensuring stable denitrification by anaerobic ammonia-oxidation. Compared with short-range nitrification / anaerobic ammonia-oxidation, the oxygen produced by microalgae causes less disturbance to the microenvironment than mechanical aeration, which is beneficial to ensuring the activity of anaerobic ammonia-oxidizing bacteria. In addition, microalgae can save a lot of energy consumption instead of mechanical aeration. Therefore, the biofilm obtained by the domestication method provided by the present invention is more stable and the treatment effect is also more stable.

[0073] At the same time, the core functional microorganisms of the anaerobic ammonia oxidizing bacteria, short-range nitrifying bacteria and microalgae coupling system provided by the present invention are all autotrophic, which makes the system unnecessary to add additional organic carbon sources and can effectively absorb CO 2 , achieving negative carbon emissions. This energy-saving and high-efficiency feature is not only highly consistent with my country's "dual carbon" goals and the needs of green water plant transformation, but also shows great practical application value. Compared with the traditional bacterial-algae symbiotic sewage treatment system, such as the combination of microalgae and nitrifying and denitrifying bacteria, the coupling system provided by the present invention not only saves the step of adding organic carbon sources, but also can reduce CO2 emissions during operation. 2 emissions, thus showing significant advantages in both environmental protection and economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0074] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0075] Figure 1 Schematic diagram of the packing frame structure, biological packing, and distribution of microorganisms (bacteria or microalgae) in the reactor of the present invention;

[0076] Figure 2 It is a schematic diagram of the structure and cross section of the packing frame of the present invention;

[0077] Figure 3 It is a schematic cross-sectional view of the filling area of ​​the inner layer, middle layer and outer layer biological filler of the present invention;

[0078] Figure 4 It is a schematic diagram of the longitudinal sections of the inner layer, middle layer and outer layer biological filler and the gradient change of dissolved oxygen and light intensity of the present invention;

[0079] Figure 5 The ion monitoring concentration values ​​and total nitrogen removal rate calculation results of the anaerobic ammonia-oxidizing bacteria, short-range nitrifying bacteria and microalgae coupling system at different stages in the embodiment of the present invention; wherein ini represents the ion concentration of sewage inlet; eff represents the ion concentration of effluent. DETAILED DESCRIPTION

[0080] To make the purpose, technical scheme and advantages of the present invention clearer, the technical scheme in the present invention will be clearly and completely described below. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present invention. If the specific conditions are not specified in the embodiments, they are carried out according to the normal conditions or the conditions recommended by the manufacturer. If the manufacturer is not specified in the reagents or instruments used, they are all conventional products that can be purchased commercially.

[0081] The methods for obtaining various biological materials described in the examples are only provided as an experimental method to achieve the specific disclosed purpose, and should not be construed as limiting the sources of the biological materials of the present invention. In fact, the sources of the biological materials used are extensive, and any biological material that can be obtained without violating laws and moral ethics can be replaced and used according to the instructions in the examples.

[0082] The terms "including" and "having" and any variations thereof of the present invention are intended to cover non-exclusive inclusions. For example, a process, method, apparatus, product or equipment comprising a series of steps is not limited to the listed steps or modules, but may optionally include steps that are not listed, or may optionally include other steps that are inherent to these processes, methods, products or equipment. The "plurality" mentioned in the present invention refers to two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B may represent: A exists alone, A and B exist at the same time, and B exists alone. The character " / " generally indicates that the previously associated objects are in an "or" relationship.

[0083] In some specific embodiments of the present invention, the anaerobic ammonium oxidation sludge is reddish brown, granular, and has a denitrification effect of ≥85%. The short-range nitrification sludge is yellowish brown, flocculent, and has a nitrite accumulation rate of ≥90%. The microalgae is Chlorella sorokinensis (Chinese Academy of Sciences Freshwater Algae Seed Bank of the Institute of Hydrobiology, Chinese Academy of Sciences (Wuhan, China)).

[0084] In some specific embodiments of the present invention, the biological filler is a polyurethane elastic filler with a particle size of 1-4 cm and a cubic shape; the filling degree of the filler in the reaction device is 10-30%.

[0085] Example 1

[0086] In this embodiment, the experimental steps mainly include four parts, namely: 1) reactor setting; 2) inner layer anaerobic ammonium oxidation sludge domestication; 3) middle layer short-range nitrification sludge domestication; 4) outer layer microalgae domestication. The specific experimental steps are as follows:

[0087] 1. Add an inner layer of polyurethane biofiller to a 4L SBR reactor packing rack. The reactor packing rack features two parallel acrylic plexiglass plates connected by an iron column in the middle, and the polyurethane biofiller can be embedded in the iron column. The iron column is divided into inner, middle and outer iron columns, which are used to embed different layers of biofillers. The thickness ratio of the inner, middle and outer biofiller filling areas is 3:2:1 respectively. The outer biofiller filling area has the thinnest thickness to control the algae growth area and prevent the internal algae from being unable to receive light. The inner biofiller filling area has the highest thickness, which helps to form an anaerobic environment for anaerobic ammonia oxidation in the inner biofiller.

[0088] The inner biological filler is embedded in the inner iron column of the filler frame, and then the anaerobic ammonium oxidation sludge and the NH 4 + -N and NO 2 - -N wastewater is mixed and added into the reactor, NH 4 + -N and NO 2- The ratio of NH-N is 1:1.32, and the wastewater in the reactor is NH 4 + -N concentration was controlled at 100 mg / L, NO 2 - -N concentration is controlled at 132mg / L, and anaerobic ammonium oxidation sludge concentration is 3500mg / L. The reactor is equipped with a heating device to maintain the temperature at 25-30℃.

[0089] 2. Start stirring at a speed of 150 rpm to promote the gradual growth of anaerobic ammonium oxidation sludge on the inner biological filler. Anaerobic ammonium oxidation bacteria carry out anaerobic ammonium oxidation denitrification reaction. Each reaction cycle is set to 10 hours. 4 + -N and NO 2 - After the reaction was complete, stop stirring, let stand for 15 min, drain all the supernatant, and then add 100 mg / L NH 4 + -N and 132mg / L NO 2 - -N wastewater enters the reactor for further domestication.

[0090] 3. Repeat step 2. After 30 cycles of acclimatization, the anaerobic ammonium oxidation sludge grows in large quantities on the inner biological filler. When the surface color of the inner biological filler is obviously reddish brown, the reactor effluent NH 4 + -N and NO 2 - When the concentration of -N is lower than 2 mg / L after 10 h of reaction, the anaerobic ammonium oxidation sludge on the inner biological filler is considered to be fully domesticated. 4 + -N concentration is 100±5mg / L, NO 2 - -N concentration is 132±5mg / L, the reaction time is 10h per cycle, and the total nitrogen removal rate can reach about 88% under the condition of temperature 30℃. Then the middle layer polyurethane filler is embedded into the middle layer iron column of the reactor filler frame to ensure that the middle layer polyurethane filler area covers the inner layer biological filler area where anaerobic ammonium oxidation sludge grows. Then the short-range nitrification sludge is mixed with the NH 4 + -N sewage was mixed and added into the reactor. The concentration of short-range nitrification sludge in the reactor was 1500 mg / L, and the sewage NH 4 + -N concentration is controlled at 100 mg / L. The reactor is equipped with an aeration device to provide appropriate dissolved oxygen in the reactor.

[0091] 4. Turn on the stirring and aeration device, the stirring speed is 200rmp, and the aeration device controls the dissolved oxygen in the reactor to about 0.6mg / L. The short-range nitrification sludge mainly grows on the middle layer of biological filler. 4 + After the reaction was complete, stop stirring and aeration, let it stand for 15 minutes, drain all the supernatant, and then add 100 mg / L NH 4 + -N wastewater enters the reactor for further domestication.

[0092] 5. Repeat step 4 for several times. After 30 cycles of acclimation, when the surface color of the middle layer of biological filler is obviously yellow-brown, and the NH 4 + When the concentration of -N is lower than 2 mg / L after 10 hours of reaction, it indicates that the short-range nitrification sludge acclimation on the middle biological filler is completed. 4 + -N concentration is 100±5mg, each cycle reaction is 10h, temperature is 30℃, and total nitrogen removal rate under mechanical aeration conditions is about 87%. Then the outer polyurethane filler is embedded into the outer iron column of the reactor filler frame to ensure that the outer polyurethane filler area covers the middle biological filler area where short-range nitrification sludge grows. Finally, the microalgae and the NH containing only 100mg / L are added. 4 + -N sewage is mixed and added into the reactor. Meanwhile, four LED lighting devices are placed around the reactor, with the lighting surface vertically aligned with the outer biological filler.

[0093] 6. Turn on the stirring and lighting devices, the stirring speed is 200 rpm, and the light intensity is 280 μmol / (s·m 2 ). When the NH 4 + After the reaction was complete, the stirring and illumination devices were stopped, and after standing for 15 min, all the supernatant was discharged and then supplemented with 100 mg / L NH 4 + -N wastewater enters the reactor for further domestication.

[0094] 7. Repeat step 6 for several times. After 30 cycles of acclimation, it can be found that the outer layer of biological filler is obviously green in color. At the same time, the NH 4 + -N is removed by reaction within 10 hours, and the effluent NH 4 + When the -N concentration is lower than 2 mg / L, the microalgae are successfully domesticated on the outer biological filler, and the system construction is completed. At this time, the coupling system is 4 +When the -N concentration was 100±5mg / L, the reaction period was 10h, the illumination time was 10h, and the temperature was 30℃, the total nitrogen removal rate was stable at more than 90%.

[0095] The calculation formula for total nitrogen removal rate in sewage is:

[0096] Total nitrogen removal rate (%) = [(system initial total nitrogen concentration - effluent total nitrogen concentration) / inlet total nitrogen concentration] × 100%;

[0097] Among them, the initial total nitrogen concentration of the system refers to the total nitrogen concentration at the beginning of the system reaction (mg / L), the inlet total nitrogen concentration refers to the sum of the initial ammonia nitrogen and nitrite nitrogen concentrations of the system reaction (mg / L), and the outlet total nitrogen concentration refers to the total nitrogen concentration at the system outlet (mg / L).

[0098] Water samples were collected at the beginning and end of the reaction stage of the sewage treatment system. Total nitrogen mainly includes ammonia nitrogen, nitrite nitrogen and nitrate nitrogen, which were determined by Nessler's reagent spectrophotometry, N-(1-naphthyl)-ethylenediamine spectrophotometry and thymol method, respectively, and repeated three times in parallel, and data processing and analysis were performed.

[0099] The results show that ( Figure 5 ), when the anaerobic ammonium oxidation sludge on the inner biological filler is successfully domesticated, the total nitrogen removal rate can reach about 88%. The short-range nitrification sludge on the middle biological filler is also successfully domesticated. At this time, the total nitrogen removal rate of the system is about 87%. Finally, the microalgae on the outer biological filler are successfully domesticated, and the system has a total nitrogen removal rate of about 87%. 4 + When the -N concentration was 100±5mg / L, the total nitrogen removal rate was stable at more than 90%.

[0100] Example 2

[0101] In order to verify the coupling system provided by the present invention, the efficiency of achieving high total nitrogen removal rate without external aeration and carbon source, and to compare the energy consumption and carbon source consumption with the traditional method, the following experiments were conducted:

[0102] Experimental group: The anaerobic ammonia-oxidizing bacteria, short-range nitrifying bacteria and microalgae coupling system successfully domesticated in Example 1 were used. In this system, no external aeration device was used, but only natural dissolved oxygen or oxygen produced by biological activities in the reactor was relied on to maintain the dissolved oxygen concentration required for the reaction. No external carbon source was added. At the same time, this group did not add any external carbon source, and only used organic matter in sewage and organic matter produced by photosynthesis of microalgae as carbon sources. During the experiment, data collection and analysis were carried out: water samples were collected at the inlet and outlet at the beginning and end of the reaction stage of the sewage treatment system. The total nitrogen (including ammonia nitrogen, nitrite nitrogen and nitrate nitrogen) was determined by Nessler's reagent spectrophotometry, N-(1-naphthyl)-ethylenediamine photometry and thymol method, and 3 parallel repeated experiments were performed. Finally, we calculated the total nitrogen removal rate and compared the removal effects under different experimental conditions.

[0103] Control group: The setting of the control group was based on the study on the cultivation and treatment characteristics of Chlorella-aerobic sludge coupled particles (published in Industrial Water Treatment, Vol. 44, No. 9, 2024). The control group used a combination of traditional algae and nitrifying and denitrifying bacteria, and the TN removal rate reached a range of 53.14% to 89.37%, but this process required the addition of a carbon source, sodium acetate (NaAc), to the influent.

[0104] Theoretical process of nitrification and denitrification 2 The calculation formula refers to the following reaction formula:

[0105] Nitrification process: NH 4 + +1.83O 2 +1.98HCO 3 - →0.021C 5 H 7 NO 2 +1.041H 2 O+0.98NO 3 - +1.88H 2 CO 3

[0106] Denitrification process: NO 3 - +1.08CH 3 OH+H + →0.065C 5 H 7 NO 2 +0.47N 2 +0.76CO 2 +2.44H 2 O

[0107] From the above reaction equation, it can be seen that the whole process of nitrification and denitrification emits CO 2 However, in the coupled system of anaerobic ammonium oxidizing bacteria, short-range nitrifying bacteria and microalgae, the microorganisms are all autotrophic, so CO 2 of negative emissions.

[0108] In terms of energy consumption, this example calculates the energy consumed by the air pump in the short-range nitrification / anaerobic ammonium oxidation stage and the energy consumed by the LED lamp in the bacteria-algae symbiosis stage. Specifically, the short-range nitrification / anaerobic ammonium oxidation stage consumes 3.75 kWh / Kg-N of energy at an airflow rate of 60 mL / min, while the A / PN / A system (i.e., anaerobic ammonium oxidizing bacteria, short-range nitrifying bacteria, and microalgae coupling system) consumes about 2.26 kWh / kg-N under LED lighting conditions, and the energy consumption is reduced by about 40%.

[0109] The experimental results show that the coupling system provided by the present invention achieves a total nitrogen removal rate of more than 90% without the addition of aeration and carbon source. Compared with the short-range nitrification / anaerobic ammonium oxidation process, the energy consumption is reduced by about 40%. In addition, the algae can assimilate nitrogen, which improves the total nitrogen removal rate to a certain extent. Compared with the traditional bacteria-algae symbiotic sewage treatment system (microalgae coupled nitrification and denitrification system), no external organic carbon source is required in the influent, saving 100% of the external organic carbon source, and at the same time achieving CO 2 of negative emissions.

[0110] Therefore, the domestication method provided by the present invention can cultivate a green, environmentally friendly and sustainable anaerobic ammonia-oxidizing bacteria, short-range nitrifying bacteria and microalgae coupled efficient biological denitrification system, which can provide a new idea for future urban sewage denitrification treatment.

[0111] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for acclimating a coupled system of anaerobic ammonia oxidizing bacteria, short-range nitrifying bacteria and microalgae, characterized in that: The steps include: S1. constructing a reactor, wherein the reactor comprises a packing frame structure, wherein the packing frame structure comprises two plates arranged in parallel and a connecting support between the two plates; The material of the plate is transparent reinforced plastic; The connecting struts include inner connecting struts, middle connecting struts and outer connecting struts, which are used to embed and fix the inner biological filler, the middle biological filler and the outer biological filler respectively; The reactor is provided with a stirring device, an aeration device and a temperature control device; the reactor is provided with lighting devices around it for vertically illuminating the outer biological filler; First, only the inner layer biological filler is embedded on the inner layer connecting pillar; S2, prepare NH4 + -N and NO2 - -N sewage, and after mixing the anaerobic ammonium oxidation sludge with the sewage, add it into the reactor and start stirring to make the anaerobic ammonium oxidation sludge adhere to and grow on the surface of the inner biological filler; when NH4 + -N and NO2 - -N When the reaction is finished, stop stirring, let it stand for 15-30 minutes, then drain the supernatant and add new NH4 + -N and NO2 - -N sewage, start stirring again until NH4 + -N and NO2 - -N The reaction is completed again, then stop stirring and let stand for 15-30 minutes; S3, repeat step S2 until the anaerobic ammonium oxidation sludge is tamed, and then embed the middle-layer biological filler into the middle-layer connecting pillar, so that the middle-layer biological filler completely covers the area on the inner-layer biological filler where the anaerobic ammonium oxidation sludge is attached; short-range nitrification sludge and NH4 + -N sewage is mixed and added into the reactor; S4, start aeration and stirring, so that the short-range nitrification sludge adheres to the surface of the middle biological filler, and waits for the NH4 + After the reaction is complete, stop aeration and stirring, let it stand for 15-30 minutes, then drain the supernatant and add new NH4 + -N sewage, turn on aeration and stirring again until NH4 + -N The reaction is completed again, then aeration and stirring are stopped and the mixture is allowed to stand for 15-30 minutes; S5, repeat step S4 until the short-range nitrification sludge is tamed, embed the outer biological filler into the outer connecting pillar, so that the outer biological filler completely covers the area on the middle biological filler where the short-range nitrification sludge is attached; then, place the microalgae and the NH4 + -N sewage is mixed and added into the reactor; S6, turn on the lighting and stirring, so that the microalgae can attach and grow on the surface of the outer biological filler, and wait for the NH4 + After the reaction is complete, stop lighting and stirring, let it stand for 15-30 minutes, then drain the supernatant and add new NH4 + -N sewage, turn on the lighting and stirring again until the NH4 + -N The reaction is completed again, then stop lighting and stirring and let it stand for 15-30 minutes; S7. Repeat step S6 until the microalgae domestication is completed.

2. The acclimation method according to claim 1, characterized in that: In step S2, the NH4 + -N and NO2 - -N sewage, including NH4 + -N concentration 80-120mg / L, NH4 + -N and NO2 - The molar ratio of -N is 1:1.

32.

3. The acclimation method according to claim 1, characterized in that: In steps S3-S6, the NH4 + -NH4 in sewage + -N concentration 80-120mg / L.

4. The acclimation method according to claim 1, characterized in that: In step S2, the concentration of the anaerobic ammonium oxidation sludge is 3000-4000 mg / L.

5. The acclimation method according to claim 1, characterized in that: In step S3, the concentration of the short-cut nitrification sludge is 1000-2000 mg / L.

6. The acclimation method according to claim 1, characterized in that: In step S5, the concentration of the microalgae is 200-500 mg / L.

7. The acclimation method according to claim 1, characterized in that: The thickness of the filling area formed by the inner layer biological filler is the largest, and the thickness of the filling area formed by the outer layer biological filler is the smallest.

8. The acclimation method according to claim 1, characterized in that: In step S3, the anaerobic ammonium oxidation sludge is acclimated by at least one of the following methods (a1)-(a3): (a1) Repeat step S2 until a stable reddish brown sludge layer is formed on the surface of the inner biological filler and the NH4 + -N completely removed; (a2) repeating step S2 at least 30 times; (a3) repeating step S2 until the total nitrogen removal rate in the sewage is ≥85%; In step S5, the short-range nitrification sludge acclimation is completed by at least one of the following methods (b1)-(b3): (b1) Repeat step S4 until a stable yellow-brown sludge layer forms on the surface of the middle biological filler and can convert NH4 + -N completely removed; (b2) repeating step S4 at least 30 times; (b3) repeating step S4 until the total nitrogen removal rate in the sewage is ≥85%; In step S7, the microalgae are domesticated by at least one of the following methods (c1)-(c3): (c1) Repeat step S6 until a stable green layer is formed on the surface of the outer biological filler and the NH4 + -N completely removed; (c2) repeating step S6 at least 30 times; (c3) Repeat step S6 until the total nitrogen removal rate in the sewage is ≥ 85%.

9. The acclimation method according to claim 1, characterized in that: The biological filler is a polyurethane elastic filler with a particle size of 1-4 cm and a cubic shape; the filling degree of the biological filler in the reaction device is 10-30%; the stirring speed is 150-250rpm; the aeration controls the dissolved oxygen in the reactor to be 0.50-0.80mg / L; the temperature control device controls the reactor temperature to be 25-30°C; the illumination intensity is 250-300μmol / (s·m 2 ).

10. The coupled system of anaerobic ammonia-oxidizing bacteria, short-range nitrifying bacteria and microalgae constructed by the domestication method according to any one of claims 1 to 9, characterized in that: The system is used for biological denitrification. Under light conditions, the system does not require aeration or an external organic carbon source, and forms a dissolved oxygen gradient zone change through an outer microalgae oxygen production zone, a middle short-range nitrification oxygen consumption zone, and an inner anaerobic ammonia oxidation anaerobic denitrification zone.

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