Rotating nitrogen and phosphorus interception bio-bed for integrated farming and breeding farms and its use method

Abstract

The present invention relates to a rotary nitrogen and phosphorus interception bio-bed for integrated farming and aquaculture farm and a method for using the same. The present invention maximizes the decontamination effect of activated sludge by utilizing a rotary module design, and at the same time intercepts nitrogen and phosphorus elements in wastewater discharged from the farming end of the integrated farming and aquaculture farm by introducing phytoplankton. Nutrients are redistributed to the land by returning the phytoplankton to the fields, and the emission of active nitrogen gas from the planting end during the growing season is reduced. Water resources are saved and energy consumption is reduced by reusing the purified wastewater. This provides a simple and cost-effective method for avoiding potential risks of non-point source pollution that may be caused by high nitrogen and phosphorus loads in integrated farming and aquaculture farms. The use of biological nitrogen and phosphorus fixation not only achieves the purpose of nutrient redistribution but also ensures the cleanliness and environmental protection of the entire process.

Description

Technical Field

[0001] The present invention relates to the field of agricultural non-point source pollution prevention and control, and in particular to a rotary nitrogen and phosphorus interception bio-bed for a farming-breeding integrated farm and a method for using the same. Background Art

[0002] Chinese invention patent CN201410794856.0 discloses a method for preventing and controlling regional farmland non-point source pollution using a farmland ditch and pond system. By improving farmland irrigation and drainage ditches and adding ecological ponds, the loss of nitrogen and phosphorus nutrients is cut off from the end. Also taking the last link of agricultural non-point source pollution, namely the discharge of sewage, as the entry point, Chinese invention patent CN201811396652.6 discloses a combined farmland non-point source sewage purification device, its purification process, and its application. This invention reduces the emission of nitrogen and phosphorus elements by introducing a sewage evolution device in the field. In addition to taking preventive measures for the return of water from crop production, many studies have focused on reducing the application of chemical fertilizers through methods such as organic fertilizer substitution, water and fertilizer integration, fertilizer quotas, and soil testing and formula fertilization, thereby cutting off the input of redundant nutrients from the source. However, most of these solutions require professionals to conduct preliminary research and pilot work, which not only takes a long time, but also requires a certain level of financial commitment. Phytoplankton naturally present in farmland ecosystems have strong nitrogen and phosphorus fixation capabilities, fast growth cycles, and good nutrient regulation effects. Utilizing these plants as resources can, to a certain extent, achieve low-cost and high-ecological-efficiency resource recycling. For example, Chinese invention patent CN202210393123.0 discloses a method for using duckweed to control the pH value of farmland and improve the utilization rate of nitrogen fertilizer in farmland, while Chinese invention patent CN201410332895.9 ferments duckweed to produce organic fertilizer, realizing the secondary utilization of duckweed's purification function.

[0003] The current primary treatment method for eutrophic livestock and poultry wastewater is the activated sludge water treatment process. After separating the organic matter in the wastewater from the water through physical filtration or chemical adsorption, it creates a suitable living environment for specific microorganisms, such as anaerobic, anoxic, and aerobic microorganisms, improving biodegradability and achieving the goal of removing different pollutants. Chinese invention patent CN201610510425.6 discloses a method for treating livestock and poultry wastewater to meet discharge standards. This method utilizes a two-stage anaerobic reactor to achieve efficient and standard discharge treatment of livestock and poultry wastewater. In addition, it produces renewable energy biogas through continuous stirring fermentation. Chinese invention patent CN201910617650.3 discloses a method for treating livestock and poultry wastewater based on dual-membrane solar technology. This method combines photocatalytic degradation with biofilm treatment, achieving energy conservation and emission reduction. Although activated sludge has excellent organic matter decomposition activity, water treatment processes involving activated sludge often involve sludge recycling, which requires additional energy consumption, while using sludge alone in a certain process reduces work efficiency. By rationally designing the operating modes and rules of each system, the treatment efficiency of activated sludge can be maximized.

[0004] The main prevention and control measures for farm non-point source pollution at the planting and breeding ends, as well as potential new technologies, have been described above. However, with the increasing scarcity of arable land and the increasing demand for food production, traditional single-function agricultural units will inevitably shift to multifunctional integrated planting and breeding. How to achieve harmless nitrogen and phosphorus emissions from integrated planting and breeding farmland through technological combination improvements is a major national issue that must be addressed in the future. However, there is currently a lack of ideas and attempts to comprehensively consider nutrient retention and redistribution from the perspective of the entire ecosystem. Summary of the Invention

[0005] The purpose of the present invention is to overcome the defects of the above-mentioned prior art and provide a rotating nitrogen and phosphorus retention biological bed for integrated farming and breeding farms and a method for using the same. The present invention maximizes the decontamination effect of activated sludge by utilizing a rotary module design, and at the same time intercepts nitrogen and phosphorus elements in wastewater discharged from the breeding end of the integrated farming and breeding farm by introducing phytoplankton. By returning phytoplankton to the fields, nutrients are redistributed into the land, and the emission of active nitrogen gas during the growing season at the planting end is reduced. By reusing the purified wastewater, water resources are saved and energy consumption is reduced. It provides a simple and cost-effective method to avoid the potential risk of non-point source pollution caused by high nitrogen and phosphorus loads in integrated farming and breeding farms. The use of biological nitrogen and phosphorus fixation not only achieves the purpose of nutrient redistribution but also ensures the cleanliness and environmental protection of the entire process.

[0006] The purpose of the present invention can be achieved by the following technical solutions:

[0007] A rotary nitrogen and phosphorus interception bio-bed for a combined farming and breeding farm comprises a sedimentation tank, an anaerobic tank, an ecological pond, and a storage tank. The anaerobic tank, ecological pond, and storage tank are connected in pairs to form a rectangular structure. The sedimentation tank is arranged at the center of the rectangular structure and is connected to the anaerobic tank, ecological pond, and storage tank at the same time. An opening is provided on the sedimentation tank.

[0008] The sedimentation tank is used to introduce wastewater from farm animal sheds, and the storage tank is used to irrigate farmland with the purified wastewater.

[0009] When in use, the sedimentation tank is connected with the anaerobic tank, the ecological pond and the storage tank in sequence through the opening.

[0010] Furthermore, the opening on the sedimentation tank is closable, and when the sedimentation tank is connected with the anaerobic tank, the ecological pond and the storage tank, the opening is opened.

[0011] Furthermore, the sedimentation tank is a rotatable cylinder with a radius of 4 to 6 m and a depth of 5 to 7 m;

[0012] Furthermore, in the above, the cylinder has a radius of 5m and a depth of 6m.

[0013] Furthermore, the sedimentation tank contains activated sludge, which is accumulated in the sedimentation tank through continuous mixed culture. Since the sedimentation tank is a 1 / 4 open cylinder, the activated sludge in the biological bed process is connected with the anaerobic tank, ecological pond and storage tank, and always plays a role.

[0014] Furthermore, a harvesting net is provided at the junction of the anaerobic tank and the ecological pond, and the harvesting net is connected to the sedimentation tank. When the sedimentation tank rotates, the harvesting net can be driven to open or close in the ecological pond.

[0015] Furthermore, a water layer is provided in the ecological pond, the surface of which is covered with phytoplankton, including Azolla, Lemna, Spirodela polyrhiza and Spirodela multirhiza. The water layer is used to preserve the phytoplankton. The phytoplankton absorbs 2-4.5% of the biomass of nitrogen and 0.3-1.4% of the biomass of phosphorus.

[0016] Furthermore, in the above, the phytoplankton is Lemna minor.

[0017] Furthermore, in the above, the water layer height is 3-8 cm.

[0018] Furthermore, in the above, the water layer height is 5 cm.

[0019] Furthermore, the rectangular structure is 25-35 m long and 15-25 m wide.

[0020] Furthermore, the depths of the anaerobic tank, ecological pond and storage tank are 2-4m.

[0021] Furthermore, the rectangular structure is 30m long and 20m wide, and the anaerobic tank, ecological pond and storage tank are 3m deep.

[0022] Furthermore, the maximum sewage treatment capacity of the biological bed is 300m 3 .

[0023] A method for using a rotating nitrogen and phosphorus retention bio-bed for a farming-aquaculture farm, the specific steps are as follows:

[0024] S1. The wastewater from the farm animal shed is introduced into a sedimentation tank. The sedimentation tank opening is closed at this time. After the wastewater stays in the sedimentation tank for a period of time, the wastewater is obtained after precipitation and solid-liquid separation.

[0025] S2. Rotate the sedimentation tank 90° clockwise to open the sedimentation tank opening, and turn the sedimentation tank opening to the anaerobic tank. The wastewater after solid-liquid separation obtained in step S1 is introduced into the anaerobic tank. After staying in the anaerobic tank for a period of time, the wastewater after anaerobic decomposition is obtained.

[0026] S3, the sedimentation tank is rotated 90 degrees clockwise, and the opening of the sedimentation tank is turned from the anaerobic tank to the ecological pond. The wastewater after anaerobic decomposition obtained in step S2 is introduced into the ecological pond. After staying in the ecological pond for a period of time, the sedimentation tank drives the harvesting net to be opened in the ecological pond. The phytoplankton in the ecological pond purifies the wastewater after anaerobic decomposition to obtain purified wastewater;

[0027] S4. The sedimentation tank is rotated 90° clockwise, and the opening of the sedimentation tank is turned from the ecological pond to the storage tank, and the purified wastewater obtained in step S3 is introduced into the storage tank. At the same time, the sedimentation tank drives the harvesting net to close in the ecological pond, and the water in the storage tank is used to irrigate farmland.

[0028] Furthermore, in step S1, the residence time of the wastewater in the farm breeding shed in the sedimentation tank depends on the single sewage treatment volume target.

[0029] Furthermore, in step S1, the farmed animals include pigs, cattle, sheep, chickens, ducks and geese.

[0030] Furthermore, in step S2, the residence time of the wastewater after solid-liquid separation in the anaerobic tank is 2-6 days.

[0031] Furthermore, in step S3, the residence time of the wastewater after anaerobic decomposition in the ecological pond is 6-9 days.

[0032] Furthermore, in step S3, the wastewater after anaerobic decomposition obtained in step S2 is diluted with water and then introduced into the ecological pond.

[0033] Furthermore, the wastewater after anaerobic decomposition is diluted with water to a total phosphorus concentration of ≤36 mg / L, a total nitrogen concentration of ≤222 mg / L, an ammonia nitrogen concentration of ≤394 mg / L, and a nitrate nitrogen concentration of ≤160 mg / L.

[0034] Furthermore, the wastewater after anaerobic decomposition is diluted with water to a total phosphorus concentration of ≤2.25 mg / L, a total nitrogen concentration of ≤24.59 mg / L, an ammonia nitrogen concentration of ≤13.9 mg / L, and a nitrate nitrogen concentration of ≤10.03 mg / L, at which time the nitrogen and phosphorus retention effect is optimal.

[0035] Furthermore, in step S3, when the sedimentation tank opening is turned from the anaerobic tank to the ecological pond, the harvesting net is fanned out in the ecological pond with an opening angle of 90 degrees, and the phytoplankton spreads and covers the harvesting net.

[0036] Furthermore, in step S4, when the opening of the sedimentation tank turns from the ecological pond to the storage tank, the harvesting net is fanned in the ecological pond, and the harvesting net recovers part of the phytoplankton, which is directly returned to the field. After the phytoplankton is returned to the field, it has the effect of reducing the emission of active nitrogen gas during the crop growing season.

[0037] Furthermore, in step S4, the total phosphorus removal rate of the wastewater after purification in the storage tank is in the range of 5-90%, the total nitrogen removal rate is in the range of 50-95%, the ammonium nitrogen removal rate is in the range of 50-90%, and the nitrate nitrogen removal rate is in the range of 5-100% compared with the wastewater after solid-liquid separation in the anaerobic tank.

[0038] Furthermore, in step S4, after the water in the storage pool is used to irrigate the farmland, the emission of active nitrogen gas during the growing season of the farmland is detected.

[0039] Furthermore, the method for detecting the emission of reactive nitrogen gas is as follows: soil with a maximum moisture content is placed in a sealed box and air is introduced into the box until the soil is dried, simulating alternating wet and dry conditions of the soil, and the reactive nitrogen gas emission flux, peak emission value, and total emission value are measured using a high performance liquid chromatograph. The reactive nitrogen gas includes HONO and NOx.

[0040] Compared with the prior art, the present invention has the following beneficial effects:

[0041] (1) The present invention utilizes a rotary module design to enable activated sludge to participate in decontamination in situ at every stage of sewage treatment without increasing additional energy consumption, thereby increasing the connectivity of the system, saving the cost of constructing different modules separately, and improving the metabolic rate of organic matter in wastewater.

[0042] (2) The phytoplankton of the present invention not only intercepts nitrogen and phosphorus in the wastewater from the aquaculture end of the integrated farming and breeding farm through nutrient absorption and assimilation, but also helps to reduce the gas loss of nutrients during the crop production process at the planting end after returning to the field.

[0043] (3) The phytoplankton naturally existing in the farmland system is used to assimilate nitrogen and phosphorus in the wastewater, which is green, pollution-free and easy to obtain. At the same time, the phytoplankton is automatically harvested through the rotary module, which reduces labor consumption. The harvested phytoplankton is returned to the field, which not only completes the redistribution of nutrients into the soil after interception, but also has the potential to reduce active nitrogen emissions at the planting end. By reusing the purified wastewater, water resources are saved and energy consumption is reduced. It provides a simple and cost-effective way to avoid the potential risk of non-point source pollution caused by high nitrogen and phosphorus loads in combined farming and breeding farms. The use of biological nitrogen and phosphorus fixation not only achieves the purpose of nutrient redistribution but also ensures the cleanliness and environmental protection of the entire process. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 This is a schematic diagram of the use of the rotary nitrogen and phosphorus retention bio-bed of the present invention;

[0045] Figure 2 This is a schematic diagram of the use process of the harvesting net;

[0046] Figure 3 It is a schematic diagram of the tiling structure of the harvesting net;

[0047] Figure 4 This is a schematic diagram of the alternating dry and wet conditions of the soil after duckweed was returned to the field;

[0048] Figure 5 Schematic diagram of HONO emission flux and emission peak value in different treatment groups;

[0049] Figure 6 Schematic diagram of NOx emission flux and emission peak of different treatment groups.

[0050] Explanation of the accompanying figures: 1. Sedimentation tank, 2. Anaerobic tank, 3. Ecological pond, 4. Storage tank, 5. Harvesting net. DETAILED DESCRIPTION

[0051] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0052] In a specific embodiment, the method for detecting the emission of active nitrogen gas refers to the active nitrogen detection method of Chinese invention patents CN201811123547.5 and CN201910168175.6.

[0053] Example 1

[0054] See also Figures 1 to 3This embodiment provides a rotating nitrogen and phosphorus interception bio-bed for a combined farming and breeding farm. The rotating nitrogen and phosphorus interception bio-bed is 30m long, 20m wide, and covers an area of ​​600m. 2 The center is sedimentation tank 1, with a radius of 5m, a depth of 6m and an area of ​​78.5m 2 , containing activated sludge, the sedimentation tank 1 is a cylinder with a radius of 5m and a depth of 6m, with a 1 / 4 opening on the cylinder. The opening on the sedimentation tank 1 can be closed. The left side of the sedimentation tank 1 is the anaerobic tank 2 with an area of ​​260.75m 2 , the upper right of sedimentation pond 1 is ecological pond 3, with an area of ​​208.875m 2 The lower right corner of sedimentation tank 1 is storage tank 4, with an area of ​​130.375m 2 The depths of anaerobic tank 2, ecological pond 3 and storage tank 4 are all 3m.

[0055] In addition, this embodiment also provides a method for using a rotating nitrogen and phosphorus interception bio-bed for a farming-aquaculture farm. The specific steps are as follows:

[0056] Step (1):

[0057] The wastewater from the breeding shed in this embodiment, i.e. the pig farm, is introduced into the sedimentation tank 1 with the opening closed. The daily excretion of a single pig is about 3 kg. There are 1000 pigs in the pig farm, i.e. the breeding wastewater of the breeding shed in one quarter is about 300 m3. 3 The single target treatment volume is the total amount of wastewater discharged by the pig farm in one quarter.

[0058] Step (2):

[0059] In sedimentation tank 1, about 300m3 of aquaculture wastewater was collected. 3 , that is, after about a quarter, the wastewater is completely precipitated, and the wastewater after precipitation and solid-liquid separation is obtained.

[0060] The sedimentation tank 1 is rotated 90° clockwise to open the opening of the sedimentation tank 1 and turn the opening of the sedimentation tank 1 toward the anaerobic tank 2 , and the wastewater after solid-liquid separation flows downward into the anaerobic tank 2 .

[0061] Step (3):

[0062] The wastewater after solid-liquid separation is placed in sedimentation tank 1 and anaerobic tank 2 at the same time. After staying in anaerobic tank 2 for 6 days, most of the organic matter in the wastewater after solid-liquid separation is degraded to obtain wastewater after anaerobic decomposition.

[0063] The sedimentation tank 1 rotates 90 degrees clockwise, and the opening of the sedimentation tank 1 turns from the anaerobic tank 2 to the ecological pond 3. The wastewater after anaerobic decomposition is diluted with water and then flows down to the ecological pond 3.

[0064] During the rotation of the sedimentation tank 1 , the sedimentation tank 1 drives one end of the harvesting net 5 to open in a fan shape clockwise in the ecological pond 3 with an opening angle of 90°.

[0065] Step (4):

[0066] The measured total phosphorus concentration of the wastewater entering Ecological Pond 3 was 2.25 mg / L, the total nitrogen concentration was 24.59 mg / L, the ammonia nitrogen concentration was 13.9 mg / L, and the nitrate nitrogen concentration was 10.03 mg / L;

[0067] A 5 cm water layer was left in the ecological pond 3 to preserve phytoplankton. The phytoplankton used in the ecological pond 3 in this embodiment was Lemna minor. The fresh weight growth rate of Lemna minor in the ecological pond 3 was measured to be 0.06d -1 ;

[0068] The diluted wastewater was simultaneously placed in sedimentation tank 1 and ecological pond 3. After nine days in ecological pond 3, most of the nitrogen and phosphorus in the wastewater were intercepted by duckweed. The nitrogen content in the duckweed was measured to be 2% of the biomass, and the phosphorus content was 0.3% of the biomass, resulting in purified wastewater.

[0069] The sedimentation tank 1 rotates 90° clockwise, and the opening of the sedimentation tank 1 turns from the ecological pond 3 to the storage tank 4, and the purified wastewater is introduced into the storage tank 4. During the rotation of the sedimentation tank 1, the sedimentation tank 1 drives the other end of the harvesting net 5 to close in a fan shape in the ecological pond 3.

[0070] Step (5):

[0071] Before the next treatment of the farm shed wastewater, approximately one quarter later, the duckweed residue in the harvesting net 5 was returned directly to the fields as a reserve for farmland fertilization, and the water was diverted from the storage tank 4 to be used as a reserve for farmland irrigation. The nitrogen and phosphorus removal efficiency in the water is shown in Table 1: the total phosphorus removal rate was 91%, the total nitrogen removal rate was 92%, the ammonium nitrogen removal rate was 90%, and the nitrate nitrogen removal rate was 100%.

[0072] Table 1 Application effect of rotating nitrogen and phosphorus interception biobed

[0073] Influent concentration (mg / L) Outlet concentration (mg / L) Removal rate Total phosphorus 2.25 0.2 91% Total nitrogen 24.59 1.97 92% Ammonia nitrogen 13.9 1.39 90% Nitrate 10.03 0 100%

[0074] Step (6):

[0075] The effect of returning harvested duckweed residues directly to the field on reducing reactive nitrogen gas emissions during the crop growing season was examined. The farmland in this example was a rice field, and three treatments were set up: a no-fertilization control (CK), a fertilized control (CKN), and duckweed returning (FS). The soil was placed in a sealed box with maximum moisture content and air was introduced until the soil was dry, simulating alternating soil wet-dry cycles ( Figure 4), the active nitrogen gas emissions were measured using high performance liquid chromatography. The total active nitrogen gas emissions are shown in Table 2, and the gas emission peaks are shown in Table 3. The results showed that after the duckweed residues were returned to the field, the total HONO and NOx emissions decreased by 72.4% and 52.9%, respectively ( Figure 5 、 Figure 6 ), the peak emission of HONO was significantly lower, while the peak emission of NOx and N2O did not increase. This indicates that returning duckweed residues to the field not only reduced the emission of important reactive nitrogen gases but also suppressed the emission potential of some reactive nitrogen gases. Therefore, from the perspective of the entire system, duckweed in the ecological pond not only intercepts nitrogen and phosphorus from the aquaculture wastewater of the integrated farming and breeding farm through nutrient absorption and assimilation, but also helps reduce nutrient gas losses during crop production on the planting side after its own return to the field.

[0076] Table 2 Total active nitrogen gas emissions in different treatment groups (mg / m 2 )

[0077] CK CKN FS HONO 4.152±0.148b 9.212±0.678a 2.538±1.708b <![CDATA[NO x ]]> 5.123±0.122b 7.540±0.210a 3.554±1.676b NO 4.467±0.189b 6.788±0.238a 3.338±1.614b <![CDATA[NO2]]> 0.740±0.072a 0.751±0.234a 0.216±0.069b

[0078] Table 3 Peak values ​​of reactive nitrogen gas emissions in different treatment groups (ng / m 2 )

[0079] HONO <![CDATA[NO x ]]> <![CDATA[N2O]]> CK 276.730b 266.832b 253.547b CKN 571.213a 484.913a 1296.863a FS 344.554b 468.448a 3671.618a

[0080] The above description of the embodiments is intended to facilitate understanding and use of the invention by those skilled in the art. It will be apparent that those skilled in the art can readily make various modifications to these embodiments and apply the general principles described herein to other embodiments without requiring inventive effort. Therefore, the present invention is not limited to the above-described embodiments. Improvements and modifications made by those skilled in the art based on the disclosure of the present invention, without departing from the scope of the present invention, should be within the scope of protection of the present invention.

Claims

1. A method for using a rotating nitrogen and phosphorus interception bio-bed for a farming and breeding farm, characterized in that: The rotary nitrogen and phosphorus interception bio-bed used in the integrated farming farm comprises a sedimentation tank (1), an anaerobic tank (2), an ecological pond (3) and a storage tank (4). The anaerobic tank (2), the ecological pond (3) and the storage tank (4) are connected in pairs to form a rectangular structure. The sedimentation tank (1) is arranged at the center of the rectangular structure. The sedimentation tank (1) is connected to the anaerobic tank (2), the ecological pond (3) and the storage tank (4) at the same time. An opening is provided on the sedimentation tank (1). The sedimentation tank (1) is used to introduce wastewater from farm animal sheds, and the storage tank (4) is used to irrigate farmland with the purified wastewater. The specific steps for using the rotating nitrogen and phosphorus retention bio-bed for integrated farming and breeding farms are as follows: S1. The wastewater from the farm animal shed is introduced into the sedimentation tank (1). At this time, the opening of the sedimentation tank (1) is closed. After the wastewater stays in the sedimentation tank (1) for a period of time, the wastewater is obtained after precipitation and solid-liquid separation. S2, the sedimentation tank (1) is rotated 90° clockwise, the opening of the sedimentation tank (1) is opened, and the opening of the sedimentation tank (1) is turned to the anaerobic tank (2), and the wastewater after solid-liquid separation obtained in step S1 is introduced into the anaerobic tank (2), and after staying in the anaerobic tank (2) for a period of time, the wastewater after anaerobic decomposition is obtained; S3, the sedimentation tank (1) rotates 90° clockwise, and the opening of the sedimentation tank (1) turns from the anaerobic tank (2) to the ecological pond (3), and the wastewater after anaerobic decomposition obtained in step S2 is introduced into the ecological pond (3). After staying in the ecological pond (3) for a period of time, the sedimentation tank (1) drives the harvesting net (5) to open in the ecological pond (3), and the phytoplankton in the ecological pond (3) purifies the wastewater after anaerobic decomposition to obtain purified wastewater; S4, the sedimentation tank (1) rotates 90 degrees clockwise, and the opening of the sedimentation tank (1) turns from the ecological pond (3) to the storage tank (4), and the purified wastewater obtained in step S3 is introduced into the storage tank (4). At the same time, the sedimentation tank (1) drives the harvesting net (5) to close in the ecological pond (3), and the water in the storage tank (4) is used to irrigate farmland.

2. The method for using the rotary nitrogen and phosphorus interception bio-bed for a farming-breeding integrated farm according to claim 1, characterized in that: The opening on the sedimentation tank (1) can be closed. The sedimentation tank (1) is a rotatable cylinder with a radius of 4 to 6 m and a depth of 5 to 7 m; The sedimentation tank (1) contains activated sludge.

3. The method for using the rotary nitrogen and phosphorus interception bio-bed for a farming-breeding integrated farm according to claim 1, characterized in that: A harvesting net (5) is provided at the junction of the anaerobic tank (2) and the ecological pond (3), and the harvesting net (5) is connected to the sedimentation tank (1). When the sedimentation tank (1) rotates, the harvesting net (5) is driven to open or close in the ecological pond (3); The ecological pond (3) is provided with a water layer, the surface of which is covered with phytoplankton, including Azolla, Lemna, Spirodela spp. and Spirodela spp.; The water layer height is 3-8 cm.

4. The method for using the rotary nitrogen and phosphorus interception bio-bed for a farming-breeding integrated farm according to claim 1, characterized in that: The rectangular structure is 25-35m long and 15-25m wide; The depths of the anaerobic pond (2), ecological pond (3) and storage pond (4) are 2 to 4 m; The maximum sewage treatment capacity of the rotating nitrogen and phosphorus interception biological bed is 300m3 per time. 3 .

5. The method for using the rotary nitrogen and phosphorus interception bio-bed for a farming-agriculture integrated farm according to claim 1, characterized in that: In step S1, the farmed animals include pigs, cattle, sheep, chickens, ducks and geese; In step S2, the wastewater after solid-liquid separation stays in the anaerobic tank (2) for 2-6 days.

6. The method for using the rotary nitrogen and phosphorus interception bio-bed for a farming-breeding integrated farm according to claim 1, characterized in that: In step S3, the wastewater after anaerobic decomposition is retained in the ecological pond (3) for 6-9 days; The wastewater after anaerobic decomposition obtained in step S2 is diluted with water and then introduced into the ecological pond (3); When the opening of the sedimentation tank (1) turns from the anaerobic tank (2) to the ecological pond (3), the harvesting net (5) is fanned out in the ecological pond (3) with an opening angle of 90 degrees, and the phytoplankton spreads and covers the harvesting net (5).

7. The method for using the rotary nitrogen and phosphorus interception bio-bed for a farming-breeding integrated farm according to claim 6, characterized in that: The wastewater after anaerobic decomposition is diluted with water to a total phosphorus concentration of ≤36 mg / L, a total nitrogen concentration of ≤222 mg / L, ammonia nitrogen concentration of ≤394 mg / L, and a nitrate nitrogen concentration of ≤160 mg / L.

8. The method for using the rotary nitrogen and phosphorus interception bio-bed for a farming-agriculture integrated farm according to claim 1, characterized in that: In step S4, when the sedimentation tank (1) opens from the ecological pond (3) to the storage pond (4), the harvesting net (5) is fanned out in the ecological pond (3), and the harvesting net (5) recovers part of the phytoplankton, and the phytoplankton recovered by the harvesting net (5) is directly returned to the field; The wastewater after purification in the storage tank (4) has a total phosphorus removal rate of 5-90%, a total nitrogen removal rate of 50-95%, an ammonium nitrogen removal rate of 50-90%, and a nitrate nitrogen removal rate of 5-100% compared to the wastewater after solid-liquid separation in the anaerobic tank (2); After the water in the storage tank (4) is used to irrigate farmland, the emission of active nitrogen gas during the growing season of the farmland is detected.

9. The method for using the rotary nitrogen and phosphorus interception bio-bed for a farming-agriculture integrated farm according to claim 8, characterized in that: The method for detecting the emission of reactive nitrogen gas is as follows: soil with a maximum moisture content is placed in a sealed box and air is introduced into the box until the soil is dry, simulating alternating wet and dry conditions in the soil. The reactive nitrogen gas emission flux, peak emission value, and total emission amount are measured using a high-performance liquid chromatograph. The reactive nitrogen gas includes HONO and NOx.

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