A rural livestock and poultry breeding wastewater treatment system

Abstract

The present application relates to a kind of rural livestock breeding wastewater treatment systems, including screen filter pool, biochemical treatment zone, sequencing batch reactor and contact tank connected in sequence, screen filter pool is equipped with water inlet, for input livestock breeding wastewater, the upstream side of screen filter pool is equipped with filter screen, and downstream side is solid-liquid separation zone;Biochemical treatment zone includes anaerobic tank, anoxic tank and aerobic tank connected in sequence, and wastewater is biochemically treated, and aerobic tank is connected anoxic tank by sludge return pipe;Contact tank is equipped with chlorine dioxide generator, and water body is disinfected;Screen filter pool, biochemical treatment zone, sequencing batch reactor and contact tank are all equipped with sludge outlet, and all are connected sludge pool by pipeline, and the sludge generated by screen filter pool, biochemical treatment zone, sequencing batch reactor and contact tank is discharged into sludge pool, and used as fertilizer raw material.

Description

Technical Field

[0001] This invention belongs to the field of wastewater treatment technology, specifically relating to a treatment system for rural livestock and poultry breeding wastewater. Background Technology

[0002] Livestock and poultry farming is a significant production activity in rural areas, generating substantial amounts of wastewater. This wastewater contains animal feces, urine, and feed, exhibiting high organic matter content, suspended solids, deep color, a large number of microorganisms, and significant volume fluctuations. Due to the large amount of livestock and poultry manure, the NH3-N concentration is high, posing a significant challenge to rural environmental management. Furthermore, the generation of livestock and poultry wastewater is volatile. Typically, the wastewater is temporarily stored in raw water tanks until a certain volume is reached before treatment, which helps to even out the water quality. Currently, there is no specific standard treatment method for livestock and poultry wastewater; instead, it is often integrated into rural domestic sewage systems for centralized treatment. This places a heavy load on domestic sewage treatment systems, causing fluctuations in the quality of produced water and affecting the quality of effluent. Simultaneously, wastewater from livestock and poultry farming that meets irrigation standards is not adequately recycled and utilized. Summary of the Invention

[0003] To address the above problems, the present invention provides a treatment system for rural livestock and poultry breeding wastewater, comprising a screen filter, a biochemical treatment zone, a sequencing batch reactor, and a contact tank connected in sequence. The screen filter is provided with an inlet for inputting livestock and poultry breeding wastewater. A filter screen is provided on the upstream side of the screen filter, and a solid-liquid separation zone is provided on the downstream side.

[0004] The biological treatment zone includes an anaerobic tank, an anoxic tank, and an aerobic tank connected in sequence to treat wastewater biologically. The aerobic tank is connected to the anoxic tank through a sludge return pipe.

[0005] The contact tank is equipped with a chlorine dioxide generator to disinfect the water. The screening tank, biological treatment zone, sequencing batch reactor and contact tank are all equipped with sludge discharge outlets, which are connected to the sludge tank through pipelines. The sludge generated in the screening tank, biological treatment zone, sequencing batch reactor and contact tank is discharged into the sludge tank and used as fertilizer raw material.

[0006] This invention employs an integrated treatment system comprising a screening tank, a biological treatment zone, a sequencing batch reactor (SBR), a contact tank, and a sludge tank. The screening tank's filter screen removes suspended or floating solids from the wastewater, facilitating subsequent solid-liquid separation. Due to the large fluctuations in the volume of livestock and poultry farm wastewater, the biological treatment zone and the SBR are combined in an intermittent influent manner. This simple structure eliminates the need for equalization tanks, primary sedimentation tanks, and secondary sedimentation tanks, resulting in low infrastructure and operating costs and convenient maintenance. The resulting sludge and solid waste are composted and used as fertilizer. The permeate from the contact tank is mixed with irrigation water in a specific ratio for integrated water and fertilizer application, achieving resource reuse.

[0007] Optionally, the filter tank is divided into an upstream zone and a downstream zone along the water flow direction. The shape of the upstream zone is not limited. An inlet and a filter screen are arranged sequentially on the upstream side of the upstream zone. The mesh size of the filter screen is 100-120 mesh, which greatly reduces the content of CODcr and BOD5.

[0008] The downstream section is vertical with a conical bottom, and the bottom of the cone is connected to the sludge tank through a pipe; a sand filter is installed in the downstream section.

[0009] Optionally, the biochemical treatment zone is arranged in sequence with a pre-anoxic tank, an anaerobic tank, an anoxic tank and an aerobic tank along the water flow direction. Submersible mixers are installed in the anaerobic tank, anoxic tank and aerobic tank to enhance the biochemical treatment in each zone.

[0010] The pre-anoxic tank can both treat the wastewater with anoxic conditions and serve as an equalization tank to temporarily retain the wastewater.

[0011] Because the generation of livestock and poultry farming wastewater is intermittent and fluctuating, the amount of wastewater generated is very small or non-existent when the farming area does not need to be flushed. However, the different microorganisms in each biological treatment tank must remain active to maintain their activity even when wastewater is not being treated. In existing technologies, maintaining the process conditions used during wastewater treatment and adding appropriate nutrients to each tank to maintain the activity and quantity of microorganisms results in high overall operating costs. This invention proposes the following technical solution to reduce energy consumption and operating costs in the biological treatment area when wastewater is not being treated.

[0012] Optionally, the inner wall of the aerobic tank is provided with several rings of limiting parts from top to bottom. Each ring of limiting parts is horizontal and is used to support the corresponding partition plate. The outer side of the limiting part is fixed to the inner wall of the aerobic tank, and the inner side extends into the interior of the aerobic tank.

[0013] When the aerobic tank is not treating wastewater, partition plates are hoisted into the aerobic tank. The outer edge of each partition plate overlaps the limiting part to fix the position of the partition plate. Several partition plates are also set horizontally from top to bottom.

[0014] Further optionally, when the partition plate overlaps the corresponding limiting part, there is a gap between the outer edge of the partition plate and the inner wall of the aerobic tank, so that the partition plate can move up and down in the aerobic tank.

[0015] A sealing ring is installed in the gap between the outer edge of the partition plate and the inner wall of the aerobic tank to prevent water from entering the space above and below the partition plate.

[0016] Further optional, the bottom of the aerobic tank is provided with a conventional aeration device; an aeration interface is provided on the inner wall of the aerobic tank above each limiting part, and an aeration pipe is provided on the upper surface of each partition plate. After the partition plate is installed, the aeration pipe is connected to the corresponding aeration interface, and then an external air supply device can be connected.

[0017] Each limiter has an openable exhaust port on the inner wall of the aerobic pool. When the exhaust port is opened, it can connect to the external atmospheric environment.

[0018] Optionally, the sludge and solid waste collected in the sludge pond are discharged into the existing biogas fermentation pond in the rural area, and then fermented together with the biomass waste in the existing biogas fermentation pond. The process is the same as the existing fermentation process. The solid produced by fermentation is a biological organic matter with rich components, which serves as nutrients for the pre-anoxic pond, anaerobic pond and anoxic pond.

[0019] Alternatively, burlap bags can be used to hold the solids produced during fermentation, forming nutrient bags. These bags are permeable to water and air, and when immersed in water, some of the organic matter can dissolve into the water, directly nourishing the microorganisms. The microorganisms can also attach to the burlap bags. Since the volume of the microorganisms is much smaller than the pores of the burlap bags, the microorganisms can enter the burlap bags, decompose the nutrients, and maintain their own activity. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the aerobic tank.

[0021] Figure 2 This is a schematic diagram of a biological support structure.

[0022] In the attached diagram, 1-limiting part, 2-partition plate, 3-sealing ring, 4-aeration interface, 5-aeration pipe, 6-exhaust port, 7-plant fixing trough, 8-load-bearing biological rack. Detailed Implementation

[0023] This embodiment provides a treatment system for rural livestock and poultry breeding wastewater, including a screen filter tank, a biochemical treatment zone, a sequencing batch reactor and a contact tank connected in sequence. The screen filter tank is provided with an inlet for inputting livestock and poultry breeding wastewater. A filter screen is provided on the upstream side of the screen filter tank and a solid-liquid separation zone is provided on the downstream side.

[0024] The biological treatment zone includes an anaerobic tank, an anoxic tank, and an aerobic tank connected in sequence to treat wastewater biologically. The aerobic tank is connected to the anoxic tank through a sludge return pipe.

[0025] The contact tank is equipped with a chlorine dioxide generator to disinfect the water. The screening tank, biological treatment zone, sequencing batch reactor and contact tank are all equipped with sludge discharge outlets, which are connected to the sludge tank through pipelines. The sludge generated in the screening tank, biological treatment zone, sequencing batch reactor and contact tank is discharged into the sludge tank and used as fertilizer raw material.

[0026] Optionally, the filter tank is divided into an upstream zone and a downstream zone along the water flow direction. The shape of the upstream zone is not limited. An inlet and a filter screen are arranged sequentially on the upstream side of the upstream zone. The mesh size of the filter screen is 100-120 mesh, which greatly reduces the content of CODcr and BOD5.

[0027] The downstream section is vertical with a conical bottom, and the bottom of the cone is connected to the sludge tank through a pipe; a sand filter is installed in the downstream section.

[0028] The screening tank can pre-treat livestock and poultry breeding wastewater. The filter screen filters out suspended or floating solids in the wastewater, and the solid-liquid separation mainly removes feces from the wastewater, reducing the difficulty of subsequent biological treatment, reducing the operating load of the biological treatment and the harm to the environment. The solid waste removed by the screening tank is discharged into the sludge tank, where it can be composted together with the sludge discharged from the sequencing batch reactor and the contact tank.

[0029] Optionally, the biochemical treatment zone is arranged in sequence along the water flow direction, including a pre-anoxic tank, an anaerobic tank, an anoxic tank, and an aerobic tank. Submersible mixers are installed in the anaerobic tank, anoxic tank, and aerobic tank to enhance the biochemical treatment in each zone. The pre-anoxic tank can perform anoxic treatment and also function as an equalization tank to temporarily retain wastewater.

[0030] The sequencing batch reactor is a conventional sequencing batch reactor.

[0031] Optional, such as Figures 1-2 As shown, the inner wall of the aerobic tank is provided with several rings of limiting parts 1 from top to bottom. Each ring of limiting parts 1 is horizontal and is used to support the corresponding partition plate 2. The outer side of the limiting part 1 is fixed to the inner wall of the aerobic tank, and the inner side extends into the interior of the aerobic tank.

[0032] When the aerobic tank is not treating wastewater, partition plates 2 are hoisted into the aerobic tank. The outer edge of each partition plate 2 overlaps with the limiting part 1 to fix the position of the partition plate 2. Several partition plates 2 are also arranged horizontally from top to bottom. The shape of the limiting part 1 and the partition plates 2 can be adapted to the shape of the aerobic tank.

[0033] Further optionally, when the partition plate 2 overlaps with the corresponding limiting part 1, there is a gap between the outer edge of the partition plate 2 and the inner wall of the aerobic tank, so that the partition plate 2 can move up and down in the aerobic tank.

[0034] A sealing ring 3 is installed in the gap between the outer edge of the partition plate 2 and the inner wall of the aerobic tank, so that the space above and below the partition plate 2 can be waterproof.

[0035] Further optional, the bottom of the aerobic tank is provided with a conventional aeration device; an aeration interface 4 is provided on the inner wall of the aerobic tank above each limiting part 1, and an aeration pipe 5 is provided on the upper surface of each partition plate 2. After the partition plate 2 is installed, the aeration pipe 5 is connected to the corresponding aeration interface 4, and can then be connected to an external air supply device.

[0036] Each limiting part 1 has an openable exhaust port 6 on the inner wall of the aerobic pool. When the exhaust port 6 is opened, it can connect to the external atmospheric environment.

[0037] Alternatively, after a partition plate 2 is installed, a plant fixing trough 7 is set above the partition plate 2. Aquatic plants are planted in the plant fixing trough 7, and several pebbles or soil are provided at the bottom of the plant fixing trough 7 to fix the aquatic plants and prevent them from floating to the water surface.

[0038] When the biochemical treatment area is not treating wastewater, it enters an idle period. During this period, the residual water in the aerobic tank is discharged into the pre-anoxic tank, and all aerobic sludge is discharged into the sludge tank (at this time, there is no sludge in the sludge tank; all the original sludge is discharged for fertilizer production). The aerobic tank is then emptied. A portion of the wastewater from the pre-anoxic tank is then fed into the aerobic tank until the liquid level is below the lowest limiting point. The original sludge from the aerobic tank is returned to the aerobic tank. The plant fixing trough 7 is then installed, and the corresponding partition plate is installed on the lowest limiting point, along with the corresponding sealing ring. This creates a closed space below the partition plate 2, allowing the aeration device at the bottom of the aerobic tank to aerate. The corresponding exhaust port 6 is opened, connecting this closed space to the external environment.

[0039] In the closed space at the bottom of the aerobic tank, the wastewater from the pre-anoxic tank provides a carbon source for aerobic microorganisms, the aeration device provides oxygen for the normal survival of aerobic microorganisms, and the aquatic plants in the plant fixing trough 7 also provide oxygen, reducing the aeration volume.

[0040] The two adjacent partitions also form a closed space, both of which receive wastewater from the pre-anoxic tank, both receive aerobic sludge, both are equipped with plant fixing troughs 7, and both are supplied with oxygen via aeration pipes 5. The top of each closed space is connected to the external environment through an exhaust port 6. The configuration above the uppermost partition is the same as described above, except that the top is open.

[0041] During the idle period, to maintain the activity of aerobic microorganisms, this invention divides the aerobic tank into several zones from top to bottom. Each zone's liquid surface is connected to the external environment, resulting in low water pressure within each zone (far lower than the water pressure required for the bottom aeration device when the entire aerobic tank is filled with water). This reduces the aeration energy consumption of the aeration device and each aeration pipe. The aquatic plants in the plant fixing trough 7 increase the oxygen content in the corresponding zone, further reducing aeration energy consumption. Furthermore, this invention discovers that dividing the aerobic microorganisms in the previous aerobic tank into several parts and cultivating them in different spatial zones significantly improves the activity and survival rate of the aerobic microorganisms.

[0042] Optionally, the sludge and solid waste collected in the sludge pond are discharged into the existing biogas fermentation pond in the rural area, and then fermented together with the biomass waste in the existing biogas fermentation pond. The process is the same as the existing fermentation process. The solid produced by fermentation is a biological organic matter with rich components, which serves as nutrients for the pre-anoxic pond, anaerobic pond and anoxic pond.

[0043] Alternatively, burlap bags can be used to hold the solids produced during fermentation, forming nutrient bags. These bags are permeable to water and air, and when immersed in water, some of the organic matter can dissolve into the water, directly nourishing the microorganisms. The microorganisms can also attach to the burlap bags. Since the volume of the microorganisms is much smaller than the pores of the burlap bags, the microorganisms can enter the burlap bags, decompose the nutrients, and maintain their own activity.

[0044] Alternatively, during the idle period, the original water and anoxic microorganisms in the anoxic tank are retained, and one or more burlap bags containing solids produced by fermentation are placed inside, ensuring the water completely submerges the bags. Preferably, the burlap bags are moved within the anoxic tank to evenly distribute nutrients. The movement of the burlap bags agitates the water, promoting dissolved oxygen and the movement of anoxic microorganisms. It can also activate the aeration device in the anoxic tank to provide a small amount of air.

[0045] Alternatively, during the idle period, the original water and anaerobic microorganisms in the anaerobic tank are retained, and a biological load rack 8 is installed. The biological load rack 8 has several grids arranged in a matrix inside, and each grid is used to place a burlap bag containing solids produced by fermentation. The outer side of the biological load rack 8 is equipped with a mesh to prevent the burlap bag from falling. Since the weight of the burlap bag and its contents is greater than the buoyancy, the burlap bag can be placed in the grid.

[0046] During the idle period, a biological support frame 8 is placed in the anaerobic tank. This not only provides nutrients but also allows anaerobic microorganisms to attach to the burlap bags, mesh, and netting, forming a biological support frame that increases the activity and quantity of anaerobic microorganisms, which is beneficial for subsequent wastewater treatment.

Claims

1. A treatment system for rural livestock and poultry breeding wastewater, characterized in that, It includes a screen filter, a biochemical treatment zone, a sequencing batch reactor and a contact tank connected in sequence. The screen filter is equipped with an inlet for feeding livestock and poultry breeding wastewater. The upstream side of the screen filter is equipped with a filter screen, and the downstream side is a solid-liquid separation zone. The biological treatment zone includes an anaerobic tank, an anoxic tank, and an aerobic tank connected in sequence to treat wastewater biologically. The aerobic tank is connected to the anoxic tank through a sludge return pipe. The contact tank is equipped with a chlorine dioxide generator to disinfect the water. The screening tank, biological treatment zone, sequencing batch reactor and contact tank are all equipped with sludge discharge outlets, which are all connected to the sludge tank through pipelines. The sludge generated in the screening tank, biological treatment zone, sequencing batch reactor and contact tank is discharged into the sludge tank and used as fertilizer raw material. The biochemical treatment zone is sequentially configured with a pre-anoxic tank, an anaerobic tank, anoxic tank, and an aerobic tank along the water flow direction. The inner wall of the aerobic tank is provided with several rings of limiting parts from top to bottom. Each ring of limiting parts is horizontal and is used to support the corresponding partition plate. When the aerobic tank is not treating wastewater, the partition plate is hoisted into the aerobic tank. The outer edge of each partition plate overlaps the limiting part to fix the position of the partition plate. Several partition plates are also arranged horizontally from top to bottom. A sealing ring is installed in the gap between the outer edge of the partition plate and the inner wall of the aerobic tank to ensure that the space above and below the partition plate is water-proof. The bottom of the aerobic tank is equipped with an aeration device; an aeration interface is provided on the inner wall of the aerobic tank above each limiting part, and an aeration pipe is provided on the upper surface of each partition plate. After the partition plate is installed, the aeration pipe is connected to the corresponding aeration interface, and then an external air supply device can be connected. Each limiter has an openable exhaust port on the inner wall of the aerobic pool. When the exhaust port is opened, it can connect to the external atmospheric environment. Plant fixing troughs are set at the bottom of the aerobic pool and above each partition plate. Aquatic plants are planted in the plant fixing troughs. Several pebbles or soil are placed at the bottom of the plant fixing troughs to fix the aquatic plants and prevent them from floating to the water surface. When the biochemical treatment area is not treating wastewater, it enters an idle period. The aerobic tank is emptied, and then part of the wastewater in the pre-anoxic tank is transferred into the aerobic tank. The original sludge in the aerobic tank is returned to the aerobic tank, and aeration is carried out through the aeration pipes.

2. The rural livestock and poultry breeding wastewater treatment system according to claim 1, characterized in that, The filtration tank is divided into an upstream zone and a downstream zone along the direction of water flow. The upstream zone is provided with an inlet and a filter screen in sequence on the upstream side. The mesh size of the filter screen is 100-120 mesh. The downstream section is vertical with a conical bottom, and the bottom of the cone is connected to the sludge tank through a pipe; a sand filter is installed in the downstream section.

3. The rural livestock and poultry breeding wastewater treatment system according to claim 1, characterized in that, The biochemical treatment zone is arranged in sequence along the water flow direction, including a pre-anoxic tank, an anaerobic tank, an anoxic tank, and an aerobic tank. Submersible mixers are installed in the anaerobic tank, anoxic tank, and aerobic tank to enhance the biochemical treatment in each zone. The pre-anoxic tank can perform anoxic treatment and also function as a regulating tank to temporarily retain wastewater.

4. The rural livestock and poultry breeding wastewater treatment system according to claim 3, characterized in that, The outer side of the limiting part is fixed to the inner wall of the aerobic tank, and the inner side extends into the interior of the aerobic tank.

5. The rural livestock and poultry breeding wastewater treatment system according to claim 4, characterized in that, When the partition plate overlaps the corresponding limiting part, there is a gap between the outer edge of the partition plate and the inner wall of the aerobic tank, allowing the partition plate to move up and down within the aerobic tank.

6. The rural livestock and poultry breeding wastewater treatment system according to claim 1, characterized in that, The sludge and solid waste collected in the sludge pond are discharged into the biogas fermentation pond, where they are fermented together with the existing biomass waste. The solids produced by fermentation are rich in biological organic matter, which serves as nutrients for the pre-anoxic pond, anaerobic pond, and anoxic pond.

7. The rural livestock and poultry breeding wastewater treatment system according to claim 6, characterized in that, Using burlap bags to hold the solids produced during fermentation creates nutrient bags. These bags are permeable to water and air. When immersed in water, some of the organic matter dissolves into the water, directly nourishing the microorganisms. The microorganisms can also attach to the burlap bags. Since the volume of the microorganisms is much smaller than the pores of the burlap bags, they can enter the bags, decompose nutrients, and maintain their own activity.

Images