Livestock breeding liquid manure zero emission and resourceful treatment process and device

Abstract

The application discloses a kind of liquid manure zero emission and resourceful treatment process and device for livestock and poultry breeding, belong to livestock and poultry breeding waste treatment technical field.For the low resource utilization rate of existing liquid manure, harmful substances are left in biogas slurry, and the solid-liquid separation effect is poor, easy to block and other problems, the application provides an integrated treatment process and supporting device.Process includes: liquid manure is collected to the storage device with stirring and odor collection;Large particle impurities are removed by first rotary screen, and then small particles are removed by second reciprocating rotary screen, and solid manure residue is used for composting;Liquid after two-stage separation is subjected to high-efficiency anaerobic fermentation to produce biogas;Biogas slurry is separated and purified by cross-flow ultrafiltration membrane, and concentrated liquid is returned for further treatment.The supporting solid-liquid separation device includes a main support, a first separation mechanism and a second separation mechanism, and high-efficiency separation is realized by synchronous driving of both ends and reciprocating rotation of multiple independent separation dishes.Liquid manure zero emission and high-value resource utilization are realized.

Description

Technical Field

[0001] This invention relates to the field of livestock and poultry breeding waste treatment, and in particular to a zero-discharge and resource-based treatment process and apparatus for liquid manure from livestock and poultry breeding. Background Technology

[0002] In recent years, my country's livestock and poultry farming industry has developed rapidly towards intensification and large-scale operations. However, pollution problems caused by livestock and poultry farming have become increasingly prominent. At the same time, with the improvement of living standards, residents' demand for healthy organic agriculture is increasing. The manure discharged during livestock and poultry farming contains a variety of nutrients such as nitrogen, phosphorus, potassium, and trace elements, making it very suitable for the production of organic fertilizer.

[0003] In my country, solid waste treatment in livestock and poultry farming mainly involves composting to produce organic fertilizer. For liquid manure, treatment primarily falls into two categories: one is the standard discharge process, where liquid manure undergoes solid-liquid separation, followed by biological and advanced treatment to meet discharge standards; the other is the liquid manure resource utilization process, where liquid manure, after solid-liquid separation, is anaerobically converted into biogas, and the biogas slurry is used as liquid fertilizer for returning to the fields. However, the utilization rate of livestock and poultry farm waste, especially liquid manure, is currently low in China. Standard discharge processes cannot achieve the resource recovery of nutrients in the wastewater. While traditional resource recovery processes can recover some nutrients, the value of the recovered products is low, the biogas slurry has low nutrient content, and there are potential hazards from residual heavy metals, antibiotics, and other harmful substances, hindering resource utilization.

[0004] Furthermore, existing solid-liquid separation devices mostly employ grids, inclined screens, or spiral extrusion methods, which have limited effectiveness in separating large particles, animal feathers, stones, and other impurities from liquid manure and are prone to clogging. Subsequent fine filtration often uses candle filters or microporous filters, which suffer from high energy consumption, easy filter element contamination, and difficulties in backwashing. Therefore, there is an urgent need for an integrated treatment process and a highly efficient solid-liquid separation device that can achieve zero discharge and high-value resource utilization of liquid manure from livestock and poultry farming. Summary of the Invention

[0005] To address the technical problems of low resource utilization rate, low nutrient content and residual heavy metals and antibiotics in existing livestock and poultry liquid manure treatment processes, as well as the limited separation effect, easy clogging, high energy consumption and difficult backwashing of existing solid-liquid separation devices that mostly use grids, inclined screens or spiral extrusion, this invention provides a zero-discharge and resource-based treatment process for livestock and poultry liquid manure and its supporting solid-liquid separation device. Through integrated process design and a dedicated two-stage separation device, zero discharge and high-value resource utilization of liquid manure are achieved.

[0006] This invention employs the following technical solution: a zero-discharge and resource-based treatment process for liquid manure from livestock and poultry farming, comprising the following steps: collecting liquid manure from livestock and poultry farming into a storage device equipped with a stirring system and an odor collection device; performing primary solid-liquid separation on the stored liquid manure, removing large-particle solid manure residue through rotary sieving, and composting the resulting solid manure residue for resource utilization; performing secondary solid-liquid separation on the liquid manure after primary separation, removing fine solid particles through reciprocating rotary sieving, and composting the resulting solid manure residue together with the solid manure residue obtained from primary separation; introducing the secondary separated liquid manure into a high-efficiency anaerobic fermentation device for anaerobic digestion to produce biogas for energy utilization; and introducing the biogas slurry produced by anaerobic fermentation into a membrane separation process. The pure unit performs cross-flow ultrafiltration separation and impurity removal, adopting a closed-loop concentration and separation mode. The cross-flow velocity is 0.5-2 m / s, the membrane flux is 40-75 LMH, and the solid content of the concentrate is greater than 4%. The concentrate is then returned to the secondary solid-liquid separation for further treatment. The ultrafiltration permeate is introduced into a harmless treatment unit, where residual heavy metals and antibiotics are removed sequentially through special adsorption and electrocatalytic oxidation. The harmless treated liquid is then introduced into a biogas slurry concentration unit, where it is concentrated using a fouling-resistant special reverse osmosis membrane with a concentration ratio greater than 3 and a membrane flux of 10-16 LMH. The concentrated liquid is used as a high-value-added liquid fertilizer, while the permeate is recycled for aquaculture rinsing. Throughout these steps, a monitoring and control module enables full-process signal acquisition and feedback regulation, achieving zero emissions from the treatment system. As a further optimization of the present invention, the mixing system includes mechanical mixing, gas-liquid jet mixing, or gas aeration mixing. When gas-liquid jet mixing or gas aeration mixing is used, the gas source used includes biogas or nitrogen. The odor collected by the odor collection device is transported to the tail gas treatment device of the biogas utilization system or the matching odor treatment device for treatment, thereby ensuring uniform mixing of manure and preventing sedimentation and stratification, while realizing closed treatment of odor and reuse of energy gas source, avoiding secondary pollution and reducing operating costs.

[0007] As a further optimization of the present invention, the first-stage solid-liquid separation is achieved by a motor driving the separation dish to rotate via a chain gear. The surface of the separation dish has separation holes, where large particles, stones, and animal feathers are trapped. The liquid that has been initially filtered passes through the separation holes and enters the next process. The separation dish is rotated and supported by a support frame, and a door is provided at the end of the separation dish. After opening the door, the trapped material inside the separation dish can be cleaned and the separation holes can be rinsed, thereby achieving efficient trapping and convenient cleaning of large particles, preventing blockage of the separation holes, and ensuring continuous and stable operation of the first-stage separation.

[0008] As a further optimization of the present invention, the two-stage solid-liquid separation is achieved by reciprocating motor driving the gear ring and the separation chamber to reciprocate. Multiple sets of independent separation dishes are evenly distributed circumferentially inside the separation chamber. Each independent separation dish has a secondary separation hole on its surface, which further screens and filters the liquid after the first stage separation, and the fine solid particles are trapped in the independent separation dish. A stirring rod is provided inside the separation chamber to stir and prevent clogging of the liquid passing through the secondary separation hole. An installation plate is provided at the end of the separation chamber, and a cleaning hole is provided on the installation plate. Clean water is injected through the cleaning hole to backwash the inside of the independent separation dish and the secondary separation hole. In this way, the reciprocating rotation of multiple sets of independent separation dishes improves the separation efficiency of fine particles. Combined with the stirring anti-clogging and backwashing structure, the clogging of the secondary separation hole is effectively avoided, and the equipment operation cycle is extended.

[0009] As a further optimization of the present invention, the high-efficiency anaerobic fermentation device is a UASB, UBF, or IC anaerobic reactor. The biogas produced by anaerobic digestion is purified and used for power generation, heating, or as a gas source for gas-liquid jet stirring and gas aeration stirring in the storage device. The membrane separation and purification device is a low-energy cross-flow ultrafiltration membrane. The concentrated liquid is returned to the secondary solid-liquid separation device for reprocessing, thereby realizing the energy utilization of organic matter through anaerobic fermentation and realizing energy recycling by using biogas as a stirring gas source. At the same time, the solid-liquid separation efficiency and resource recovery rate are improved by reprocessing the concentrated liquid from the membrane separation.

[0010] As a further optimization of the present invention, the adsorbent of the special adsorption device includes special resin, modified biochar or nano-adsorption particles, and the special adsorption device is divided into single-stage adsorption or two-stage adsorption; the wastewater from adsorbent regeneration or backwashing is further removed by an electrocatalytic oxidation device or an electrocatalytic oxidation device combined with a precipitation device to remove heavy metals and antibiotics; the biogas slurry concentration device is a pollution-resistant special reverse osmosis membrane, and the reverse osmosis membrane module is in the form of spiral wound or disc tube. The water produced by the reverse osmosis membrane device is reused for flushing water in livestock and poultry farms, and the concentrate from the reverse osmosis membrane device is used as liquid fertilizer for crop planting, algae cultivation or soil improvement. Thus, heavy metals and antibiotics are deeply removed through the synergistic effect of special adsorption and electrocatalytic oxidation, and high-value-added liquid fertilizer is obtained through reverse osmosis concentration, and the water is reused to achieve zero discharge.

[0011] As a further optimization of the present invention, the monitoring and control module includes a signal acquisition, signal feedback, and command feedback system; the real-time signal acquisition factors of the manure storage module and solid-liquid separation module include ammonia concentration, hydrogen sulfide concentration, aeration rate, sludge content, manure residue moisture content, and temperature; the real-time signal acquisition factors of the high-efficiency anaerobic fermentation module include COD concentration, VFA concentration, heavy metal concentration, and antibiotic concentration; the real-time signal acquisition factors of the membrane separation purification and biogas slurry concentration module include membrane flux, transmembrane pressure, ammonia nitrogen concentration, COD concentration, conductivity, and pH. Thus, through real-time monitoring and feedback regulation of key parameters throughout the entire process, the stable operation of each treatment module is ensured, achieving intelligent and zero-emission control of the treatment system.

[0012] As a further optimization of the present invention, the present invention also provides a solid-liquid separation device for liquid manure from livestock and poultry farming, used to achieve the above-mentioned primary solid-liquid separation and secondary solid-liquid separation, including a main support, casters, a fixing plate, a feeding dish, a primary separation mechanism, an equipment cover plate, a connecting plate, a secondary separation mechanism, and a secondary filter inlet; the connecting plate has a flow port; the casters are installed at the bottom of the main support, the fixing plate is fixedly installed on one side of the main support, the equipment cover plate covers the main support and is fixedly connected to the main support, the feeding dish is installed on the top of the equipment cover plate, and the connecting plate is fixedly installed on the main support. The upper part is located between the primary separation mechanism and the secondary separation mechanism. The primary separation mechanism includes a motor, rotating disc, chain belt, connecting disc, main gear, rotating gear, first drive groove wheel, connecting rod, second drive groove wheel, separation dish, separation hole, support frame and bin door. The secondary separation mechanism includes a reciprocating motor, rotating gear, gear ring, separation bin, independent separation dish, secondary separation hole, stirring rod, mounting disc, cleaning hole, bin outlet, discharge channel and lower discharge outlet. Thus, the integrated two-stage separation device realizes continuous and efficient solid-liquid separation of liquid sewage, improves separation efficiency and reduces equipment footprint.

[0013] As a further optimization of the present invention, in the primary separation mechanism, the motor drives the main gear to rotate via a rotating disk, chain belt, and connecting disk. The main gear meshes with the rotating gear, which drives the first drive grooved wheel. The first drive grooved wheel is linked to the second drive grooved wheel via a connecting rod. The first drive grooved wheel and the second drive grooved wheel are respectively connected to the tail end and the front end of the separation dish, forming a synchronous drive structure at both ends. The support frame is a cylindrical support structure, and the separation dish is rotatably supported inside the support frame. The chamber door is located at the end of the separation dish near the second drive grooved wheel. After opening the chamber door, large particle impurities trapped inside the separation dish can be cleaned and the separation holes can be rinsed. Thus, the synchronous drive structure at both ends ensures the rotational stability of the separation dish, improves the separation efficiency of large particles, and facilitates cleaning and maintenance.

[0014] As a further optimization of the present invention, in the secondary separation mechanism, each set of independent separation dishes is evenly distributed around the separation chamber, and each independent separation dish has a secondary separation hole on its surface; the stirring rod is set inside the separation chamber and fixedly installed on the surface of each independent separation dish, and is used to stir and prevent clogging of the feces passing through the secondary separation hole; the mounting plate is installed at the end of the separation chamber, and the mounting plate has multiple sets of cleaning holes, each of which is connected to the corresponding independent separation dish. High-pressure clean water is injected through the cleaning holes to backwash the inner wall of the independent separation dish and the secondary separation hole, thereby improving the secondary screening area and efficiency through the even distribution of multiple sets of independent separation dishes. Combined with the stirring and anti-clogging and high-pressure backwashing functions, it effectively prevents fine particles from clogging and ensures the long-term stable operation of the secondary separation.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. This invention achieves near-zero discharge and high-value resource utilization of liquid manure from livestock and poultry farming by combining a "storage module + solid-liquid separation module + high-efficiency anaerobic fermentation membrane block + harmless treatment module + membrane purification and resource utilization module + monitoring and control module". It solves to some extent the shortcomings of low resource value, low nutrient content of biogas slurry, secondary pollution from heavy metals and antibiotics, and difficulty in meeting discharge standards for wastewater. It achieves both zero discharge of liquid manure and the goals of water reuse and high-value resource utilization of nutrients. 2. This invention, through integrated process design, organically combines the processes of collection and storage, two-stage solid-liquid separation, anaerobic fermentation, membrane separation purification, harmless treatment, and biogas slurry concentration of livestock and poultry breeding liquid waste, realizing zero discharge and high-value resource utilization of liquid waste waste, and solving the problems of low resource utilization rate and low product added value of traditional processes.

[0016] 3. This invention employs a two-stage solid-liquid separation method that combines rotary screening with reciprocating rotary screening, and is equipped with a dedicated solid-liquid separation device. This effectively removes large particles, stones, animal feathers, and fine solid particles from liquid manure, solving the problems of limited separation effect and easy clogging of existing grid, inclined screen, or spiral extrusion methods, and significantly improving the solid-liquid separation efficiency.

[0017] 4. This invention uses a closed-loop concentration and separation mode through a membrane separation and purification device, and returns the concentrated liquid to the secondary solid-liquid separation for further treatment, avoiding pollution caused by direct discharge of concentrated liquid, while improving solid-liquid separation efficiency and resource recovery rate; the biogas slurry is concentrated through a special anti-fouling reverse osmosis membrane, and the concentrated liquid is used as a high-value-added liquid fertilizer. The permeate is returned for use in aquaculture flushing, realizing the full resource utilization of liquid manure.

[0018] 5. This invention uses a harmless treatment device to sequentially remove residual heavy metals and antibiotics through special adsorption and electrocatalytic oxidation, ensuring the safety of the effluent quality and solving the potential danger of residual harmful substances in biogas slurry affecting resource utilization in traditional resource utilization processes.

[0019] 6. This invention uses a monitoring and control module to collect and adjust key parameters of the entire process in real time, enabling the treatment system to achieve intelligent operation and zero-emission control, thereby improving the stability and reliability of the system operation.

[0020] 7. The present invention ensures long-term stable operation of the equipment and reduces maintenance costs and energy consumption through the synchronous drive structure at both ends of the solid-liquid separation device, the evenly distributed arrangement of multiple independent separation dishes, the anti-clogging stirring and high-pressure backwashing structure. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the overall process flow of the present invention; Figure 2 This is a schematic diagram of the module control of the present invention; Figure 3 This is a schematic diagram of the overall structure of the separation device of the present invention; Figure 4 For the present invention Figure 3 Schematic diagram of the disassembly and assembly structure of the equipment cover plate; Figure 5 For the present invention Figure 4 Schematic diagram of the disassembly and assembly structure of the intermediate-level separation mechanism; Figure 6 This is a schematic diagram of the connection structure of the two-stage separation mechanism of the present invention; Figure 7 For the present invention Figure 6 Diagram of the disassembly and assembly of the middle structure; Figure 8 For the present invention Figure 7 Enlarged schematic diagram of the structure of region A in the middle.

[0022] Explanation of key symbols: 1. Main support frame; 2. Casters; 3. Fixing plate; 4. Feed dish; 5. Primary separation mechanism; 6. Equipment cover plate; 7. Connecting plate; 8. Secondary separation mechanism; 71. Flow port; 851. Secondary filter inlet; 51. Motor; 52. Rotating disk; 53. Chain belt; 54. Connecting disk; 55. Main gear; 56. Rotating gear; 57. First drive pulley; 58. Connecting rod; 59. Second drive pulley; 510. Separating dish; 511. Separating hole; 512. Support frame; 513. Chamber door; 81. Reciprocating motor; 82. Rotary gear; 83. Gear ring; 831. Separation chamber; 84. Independent separation dish; 85. Secondary separation hole; 86. Stirring rod; 87. Mounting plate; 88. Cleaning hole; 89. Outlet; 810. Discharge channel; 811. Lower discharge port. Detailed Implementation

[0023] The present invention will now be further described in conjunction with the accompanying drawings and specific embodiments. It should be noted that, without conflict, the various embodiments or technical features described below can be arbitrarily combined to form new embodiments.

[0024] Example 1

[0025] Please see Figures 1-8 This embodiment provides a zero-discharge and resource-based treatment process for liquid manure from livestock and poultry farming, specifically including the following steps: S1. Manure Collection and Storage: Liquid manure discharged from large-scale livestock and poultry farms is transported to the storage device through a collection pipeline network. The storage device is a closed manure storage tank equipped with a mechanical stirring system on the top, with a stirring speed of 10-30 rpm, to prevent manure sedimentation and stratification. An odor collection hood is also installed on the top of the manure storage tank. The collected odor is transported through pipelines to the tail gas treatment device of the biogas utilization system for combustion treatment, or to the matching biological filter odor treatment device for treatment, to avoid odor leakage and secondary pollution.

[0026] S2. Primary Solid-Liquid Separation: The stored liquid sewage is pumped to the primary solid-liquid separation device. The primary solid-liquid separation device adopts a rotary screening method. Specifically, the rotating disk 52 is driven to rotate by the motor 51. The rotating disk 52 drives the connecting disk 54 to rotate via the chain belt 53. The connecting disk 54 rotates coaxially with the main gear 55. The main gear 55 meshes with the rotating gear 56 for transmission. The rotating gear 56 drives the first drive grooved wheel 57 to rotate synchronously. The first drive grooved wheel 57 is linked to the second drive grooved wheel 59 via the connecting rod 58. The first drive grooved wheel 57 and the second drive grooved wheel 59 are respectively connected to the tail end and the front end outer wall of the separation dish 510, forming a synchronous drive structure at both ends, so that the separation dish 510 rotates stably inside the support frame 512. The liquid sewage enters the separation dish 510 through the feeding dish 4. As the separation dish 510 rotates, large particles, stones, animal feathers, etc. in the liquid sewage are trapped in the separation dish 510. The preliminarily filtered liquid falls into the flow port 71 through the separation hole 511. The separation dish 510 is equipped with a door 513 at its end. The door 513 can be opened periodically to clean the trapped material inside the separation dish 510 and to rinse the separation holes 511 with water to prevent clogging. The moisture content of the trapped large-particle solid manure residue is controlled below 50%, and it is transported to the solid manure composting area for aerobic composting and fermentation to form organic fertilizer.

[0027] S3. Secondary Solid-Liquid Separation: The liquid waste from the primary separation enters the secondary solid-liquid separation device through the flow port 71. The secondary solid-liquid separation device adopts a reciprocating rotary screening method. Specifically, a reciprocating motor 81 drives a rotating gear 82 to reciprocate in both directions. The rotating gear 82 meshes with a gear ring 83, causing the separation chamber 831 to rotate reciprocally. Multiple sets of independent separation dishes 84 are evenly distributed circumferentially inside the separation chamber 831. The inlet end of each independent separation dish 84 is connected to the secondary filter feed port 851 via a corrugated hose. The liquid waste flows from the secondary filter feed port 851 into each set of independent separation dishes 84. As the separation chamber 831 rotates reciprocally, each independent separation dish 84 rotates synchronously. Fine solid particles in the liquid waste are trapped in the independent separation dishes 84 by the secondary separation holes 85. The further filtered liquid passes through the secondary separation holes 85 into the separation chamber 831. A stirring rod 86 is fixedly installed inside the separation chamber 831. The stirring rod 86 rotates with the separation chamber 831 to agitate the liquid passing through the secondary separation holes 85, preventing fine particles from accumulating and clogging the system. An installation plate 87 is located at the end of the separation chamber 831. The installation plate 87 has multiple sets of cleaning holes 88, each of which communicates with the interior of a corresponding independent separation dish 84. High-pressure clean water is injected through the cleaning holes 88 to backwash the inner walls of the independent separation dishes 84 and the secondary separation holes 85, ensuring separation efficiency. The liquid after secondary separation enters the discharge channel 810 through the outlet 89 and is finally discharged from the lower outlet 811. The retained fine solid manure residue is combined with the solid manure residue obtained in step S2 and composted for resource utilization.

[0028] S4. High-efficiency anaerobic fermentation: The liquid manure after two-stage solid-liquid separation is pumped to a UASB anaerobic reactor for high-efficiency anaerobic digestion. The temperature inside the anaerobic reactor is controlled at 35-38℃, the hydraulic retention time is 15-20 days, and the organic load is 3-5 kg ​​COD / (m3·d). During anaerobic digestion, the organic matter in the liquid manure decomposes under the action of anaerobic microorganisms to produce biogas, with a biogas yield of approximately 0.4-0.5 m3 / kg COD removal. After desulfurization and dehydration purification, part of the biogas is used for biogas power generation or boiler heating, and the other part is used as the gas source for aeration and stirring in the storage device in step S1, realizing the recycling of energy. The biogas slurry after anaerobic fermentation enters the next treatment process.

[0029] S5. Membrane Separation and Purification: The biogas slurry produced by anaerobic fermentation is pumped to a membrane separation and purification unit. This unit uses a low-energy cross-flow ultrafiltration membrane made of polyvinylidene fluoride (PVDF) or polyethersulfone (PES) with a pore size of 0.01-0.1 μm. A closed-loop concentration and separation mode is employed, with the cross-flow velocity controlled at 0.5-2 m / s, membrane flux at 40-75 LMH, and operating pressure at 0.1-0.3 MPa. During cross-flow filtration, suspended solids, colloids, and some large organic molecules in the biogas slurry are retained. The concentrated liquid has a solids content greater than 4%, and this concentrated liquid is returned to the secondary solid-liquid separation unit in step S3 for further treatment via a return pipe. This avoids pollution caused by direct discharge of the concentrated liquid and improves solid-liquid separation efficiency. The ultrafiltration permeate then proceeds to the next treatment stage.

[0030] S6. Harmless Treatment: The ultrafiltration permeate is introduced into a harmless treatment device, where residual heavy metals and antibiotics are removed sequentially through specialized adsorption and electrocatalytic oxidation. First, the ultrafiltration permeate enters a specialized adsorption device filled with modified biochar adsorbent at a height of 1.5-2.0 m and an empty bed contact time of 30-60 min. The modified biochar exhibits excellent adsorption and removal effects on heavy metals such as copper, zinc, and arsenic, as well as sulfonamides and tetracycline antibiotics in the biogas slurry, achieving a removal rate of over 80%. After adsorption saturation, the adsorbent is regenerated through backwashing, and the regenerated wastewater is discharged into the electrocatalytic oxidation device. The electrocatalytic oxidation device uses titanium-based ruthenium-iridium coated electrodes, with a current density of 10-20 mA / cm² and an electrolysis time of 60-120 min. This device deeply oxidizes and decomposes residual heavy metals and antibiotics in the regenerated wastewater, while simultaneously removing heavy metal ions through synergistic precipitation, ensuring that the concentration of heavy metals and antibiotics in the effluent is below the limits stipulated in the "Emission Standard for Pollutants from Livestock and Poultry Farming".

[0031] S7. Biogas Slurry Concentration: The harmlessly treated liquid is pumped to the biogas slurry concentration unit. The unit uses a special anti-fouling reverse osmosis membrane, with either spiral wound or disc-tube membrane modules. The membrane material is a polyamide composite membrane with a desalination rate greater than 99%. The unit operates at a pressure of 1.5-3.0 MPa, with a membrane flux of 10-16 LMH and a concentration ratio greater than 3. After reverse osmosis concentration, the nitrogen, phosphorus, potassium, and organic matter content in the concentrate is significantly increased, forming a high-value-added liquid fertilizer that can be used for crop cultivation, algae cultivation, or soil improvement. The permeate from the reverse osmosis meets the reuse water standards in the "Emission Standard for Pollutants from Livestock and Poultry Farming," and can be reused for washing livestock and poultry pens and vehicles, achieving zero discharge and full resource utilization of liquid manure.

[0032] Example 2:

[0033] Please see Figures 3-8This embodiment provides the solid-liquid separation device that is used in Embodiment 1 to realize the first-stage solid-liquid separation in step S2 and the second-stage solid-liquid separation in step S3. It includes a main support 1, casters 2, a fixing plate 3, a feeding dish 4, a first-stage separation mechanism 5, a device cover plate 6, a connecting plate 7, a second-stage separation mechanism 8, and a second-stage filter inlet 851; the connecting plate 7 has a flow port 71. The caster wheel 2 is installed at the bottom of the main support 1, the fixing plate 3 is fixedly installed on one side of the main support 1, the equipment cover plate 6 is placed on top of the main support 1 and fixedly connected to the main support 1, the feeding dish 4 is installed on the top of the equipment cover plate 6, and the connecting plate 7 is fixedly installed on the main support 1 and located between the primary separation mechanism 5 and the secondary separation mechanism 8. The primary separation mechanism 5 includes a motor 51, a rotating disk 52, a chain belt 53, a connecting disk 54, a main gear 55, a rotating gear 56, a first drive wheel 57, a connecting rod 58, a second drive wheel 59, a separation dish 510, a separation hole 511, a support frame 512, and a door 513. The motor 51 is fixedly mounted on the top of the main support 1. The output shaft of the motor 51 is fixedly connected to the rotating disk 52. The rotating disk 52 is connected to the connecting disk 54 via the chain belt 53. The connecting disk 54 is coaxially fixedly connected to the main gear 55. The main gear 55 meshes with the rotating gear 56, and the rotating gear 56 meshes with the first drive wheel 57. The drive groove wheel 57 is coaxially fixedly connected. The first drive groove wheel 57 is attached to the outer wall of the tail end of the separation dish 510. The first drive groove wheel 57 is fixedly connected to the second drive groove wheel 59 through the connecting rod 58. The second drive groove wheel 59 is attached to the outer wall of the front end of the separation dish 510. The support frame 512 is fixedly installed on the main support 1. The separation dish 510 is rotatably set inside the support frame 512. The cylinder wall of the separation dish 510 is provided with a separation hole 511. The lower end of the feeding dish 4 is connected to the inlet end of the separation dish 510. The door 513 is closable and installed at the end of the separation dish 510 away from the feeding dish 4. The secondary separation mechanism 8 includes a reciprocating motor 81, a rotary gear 82, a gear ring 83, a separation chamber 831, an independent separation dish 84, a secondary separation hole 85, a stirring rod 86, a mounting plate 87, a cleaning hole 88, a discharge port 89, a discharge channel 810, and a lower discharge port 811; The secondary filter inlet 851 is fixedly installed at the end of the separation chamber 831 and communicates with the flow port 71. Multiple sets of independent separation dishes 84 are evenly distributed circumferentially inside the separation chamber 831. The inlet end of each independent separation dish 84 is connected to the secondary filter inlet 851 via a corrugated hose. Each independent separation dish 84 has a secondary separation hole 85 on its cylindrical wall. A stirring rod 86 is fixedly installed on the outer surface of each independent separation dish 84. A mounting plate 87 is fixedly installed at the end of the separation chamber 831. A cleaning channel is provided on the mounting plate 87. The washing hole 88 is connected to the interior of the independent separation dish 84. The end of the separation chamber 831 away from the secondary filter inlet 851 is provided with an outlet 89, which is connected to the discharge channel 810. The bottom of the discharge channel 810 is provided with a lower discharge port 811. A gear ring 83 is fixedly sleeved on the outer wall of the separation chamber 831. The rotating gear 82 meshes with the gear ring 83. The reciprocating motor 81 is fixedly installed on the main support 1, and the output shaft of the reciprocating motor 81 is fixedly connected to the rotating gear 82.

[0034] Furthermore, in the primary separation mechanism 5, the motor 51 drives the main gear 55 to rotate via the rotating disk 52, the chain belt 53 and the connecting disk 54. The main gear 55 meshes with the rotating gear 56 for transmission. The rotating gear 56 drives the first driving grooved wheel 57. The first driving grooved wheel 57 is linked to the second driving grooved wheel 59 through the connecting rod 58. The first driving grooved wheel 57 and the second driving grooved wheel 59 are respectively connected to the tail end and the front end of the separation dish 510 to form a synchronous driving structure at both ends. The support frame 512 is a cylindrical support structure, and the separation dish 510 is rotatably supported inside the support frame 512; the door 513 is located at the end of the separation dish 510 near the second drive groove wheel 59. After opening the door 513, large particles of impurities trapped inside the separation dish 510 can be cleaned and the separation holes 511 can be rinsed.

[0035] Specifically, in the secondary separation mechanism 8, each group of independent separation dishes 84 is evenly distributed around the separation chamber 831, and each independent separation dish 84 has a secondary separation hole 85 on its surface; the stirring rod 86 is set inside the separation chamber 831 and fixedly installed on the surface of each independent separation dish 84, and is used to stir and prevent the feces passing through the secondary separation hole 85. The mounting plate 87 is installed at the end of the separation chamber 831. The mounting plate 87 has multiple sets of cleaning holes 88, each of which is connected to the corresponding independent separation dish 84. High-pressure clean water is injected through the cleaning holes 88 to backwash the inner wall of the independent separation dish 84 and the secondary separation holes 85.

[0036] Example 3

[0037] The difference between this embodiment and Embodiment 1 is that the stirring system in step S1 uses gas-liquid jet stirring, and the gas source used is biogas produced by anaerobic fermentation in step S4. Gas-liquid jet stirring not only achieves uniform mixing of manure and prevents sedimentation, but also allows for pre-acidification of the manure through the introduction of biogas, which is beneficial for the subsequent anaerobic fermentation process, reduces the need for external carbon sources, and lowers operating costs.

[0038] Example 4

[0039] The difference between this embodiment and Embodiment 1 is that the special adsorption device in step S6 employs a two-stage adsorption process. The first-stage adsorption device is filled with special resin to remove heavy metal ions from the biogas slurry; the second-stage adsorption device is filled with nano-adsorption particles to remove antibiotic residues from the biogas slurry. The adsorbents in both stages are backwashed and regenerated separately, and the regenerated waste liquids are combined and then enter an electrocatalytic oxidation device for further treatment. Through the synergistic effect of the two-stage adsorption, the heavy metal removal rate can reach over 95%, and the antibiotic removal rate can reach over 90%, significantly improving the harmless treatment effect.

[0040] The working principle of the overall technical solution of this invention is as follows: Liquid manure from livestock and poultry farming enters a closed storage device equipped with a stirring system and an odor collection device through a collection pipeline network. Under the stirring action, it is kept in uniform suspension and prevents sedimentation and stratification. At the same time, the odor is collected in a sealed manner and then transported to the exhaust gas treatment device for combustion or biological filter treatment to avoid secondary pollution. After storage, the liquid sewage enters the solid-liquid separation device in sequence, which consists of a main support 1, casters 2, a fixed plate 3, a feeding dish 4, a primary separation mechanism 5, an equipment cover 6, a connecting plate 7, and a secondary separation mechanism 8. The equipment cover 6 is placed above the main support 1, the feeding dish 4 is installed on the top of the equipment cover 6, and the connecting plate 7 is fixedly installed on the main support 1 and located between the primary separation mechanism 5 and the secondary separation mechanism 8. The connecting plate 7 has a flow port 71. In the primary separation mechanism 5, the motor 51 is fixedly installed on the top of the main support 1. The output shaft of the motor 51 is fixedly connected to the rotating disk 52. The rotating disk 52 is connected to the connecting disk 54 via the chain belt 53. The connecting disk 54 is fixedly connected to the main gear 55 on the same axis. The main gear 55 meshes with the rotating gear 56. The rotating gear 56 is fixedly connected to the first drive grooved wheel 57 on the same axis. The first drive grooved wheel 57 is fixedly connected to the second drive grooved wheel 59 via the connecting rod 58. The first drive grooved wheel 57 and the second drive grooved wheel 59 are respectively attached to the tail end and the front end outer wall of the separation dish 510 to form a synchronous drive structure at both ends.

[0041] The support frame 512 is fixedly installed on the main support 1. The separation dish 510 is rotatably set inside the support frame 512. The wall of the separation dish 510 has separation holes 511. The lower end of the feeding dish 4 is connected to the inlet end of the separation dish 510. Liquid sewage enters the separation dish 510 under the guidance of the feeding dish 4. Large particles, stones and animal feathers are trapped in the separation dish 510. The preliminarily filtered liquid falls into the flow port 71 of the connecting plate 7 through the separation holes 511. The end of the separation dish 510 away from the feeding dish 4 is equipped with an openable door 513. After opening the door 513, the trapped material inside the separation dish 510 can be cleaned and the separation holes 511 can be rinsed. After primary separation, the liquid enters the secondary separation mechanism 8 through the flow port 71. The secondary filter inlet 851 is fixedly installed at the end of the separation chamber 831 and communicates with the flow port 71. Multiple sets of independent separation dishes 84 are evenly distributed circumferentially inside the separation chamber 831. The inlet end of each independent separation dish 84 is connected to the secondary filter inlet 851 through a corrugated hose. The cylinder wall of each independent separation dish 84 has a secondary separation hole 85. A gear ring 83 is fixedly fitted on the outer wall of the separation chamber 831. A rotating gear 82 meshes with the gear ring 83. A reciprocating motor 81 is fixedly installed on the main support 1. The output shaft of the reciprocating motor 81 is fixedly connected to the rotating gear 82, driving the separation chamber 831 to rotate back and forth. Each independent separation dish 84 rotates back and forth synchronously for screening. Fine solid particles are trapped in the independent separation dish 84 by the secondary separation hole 85. The further filtered liquid enters the interior of the separation chamber 831. A stirring rod 86 is fixedly installed on the outer surface of each independent separation dish 84 and stirs the liquid as the separation chamber 831 rotates to prevent fine particles from accumulating and clogging.

[0042] The mounting plate 87 is fixedly installed at the end of the separation chamber 831. The mounting plate 87 is provided with a cleaning hole 88, which is connected to the interior of the independent separation dish 84. High-pressure clean water is injected through the cleaning hole 88 to backwash the inner wall of the independent separation dish 84 and the secondary separation hole 85. The end of the separation chamber 831 away from the secondary filter inlet 851 is provided with an outlet 89, which is connected to the discharge channel 810. The bottom of the discharge channel 810 is provided with a lower outlet 811, from which the liquid after secondary separation is discharged. Both stages of solid manure residue are composted for resource utilization. The liquid after secondary separation enters a high-efficiency anaerobic fermentation unit, where anaerobic microorganisms decompose organic matter to produce biogas. The biogas is purified and used for power generation, heating, or as a gas source for storage devices. The biogas slurry after anaerobic fermentation enters a membrane separation and purification unit, employing a low-energy cross-flow ultrafiltration closed-loop concentration and separation mode. Under specific cross-flow velocity and membrane flux conditions, suspended solids, colloids, and macromolecular organic matter are retained as concentrated liquid. The concentrated liquid has a solid content greater than 4% and is returned to the secondary solid-liquid separation unit for further treatment. The ultrafiltration permeate enters a harmless treatment unit, where it undergoes a combination of special adsorption and electrocatalytic oxidation. The treatment process removes residual heavy metals and antibiotics. Subsequently, the harmlessly treated liquid is concentrated using a special anti-fouling reverse osmosis membrane with a concentration ratio greater than 3. The concentrated liquid is used as a high-value-added liquid fertilizer for crop planting, algae cultivation, or soil improvement. The permeate meets the reuse standards and is reused for flushing livestock and poultry farms. The entire process uses a monitoring and control module to collect and control key parameters such as ammonia concentration, hydrogen sulfide concentration, COD, VFA, membrane flux, transmembrane pressure, conductivity, and pH in real time. This ensures that the treatment system has no wastewater discharge, no waste gas emission, and no solid waste disposal during the treatment process, truly achieving zero discharge and high-value resource utilization of livestock and poultry farm liquid manure.

[0043] In the description of this application, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0044] Specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention. Unless otherwise specified, the embodiments and features described in this application can be arbitrarily combined with each other.

Claims

1. A zero-discharge and resource-based treatment process for liquid manure from livestock and poultry farming, characterized in that, Includes the following steps: S1. Collect liquid manure from livestock and poultry farming into a storage device, the storage device being equipped with a stirring system and an odor collection device; S2. The stored liquid fecal waste is subjected to primary solid-liquid separation. Large particles of solid fecal residue are removed by rotary screening. The resulting solid fecal residue is then composted for resource utilization. S3. The liquid fecal waste after primary separation is subjected to secondary solid-liquid separation. Fine solid particles are removed by reciprocating rotary sieve. The resulting solid fecal residue is composted together with the solid fecal residue obtained in step S2 for resource utilization. S4. The liquid manure after secondary separation is introduced into a high-efficiency anaerobic fermentation device for anaerobic digestion to produce biogas for energy utilization. S5. The biogas slurry produced by anaerobic fermentation is introduced into a membrane separation and purification device for cross-flow ultrafiltration separation and impurity removal. A closed-loop circulation concentration separation mode is adopted, with a cross-flow velocity of 0.5-2m / s, a membrane flux of 40-75LMH, and a solid content of more than 4% in the concentrate. The concentrate is then returned to step S3 for further treatment. S6. Introduce the ultrafiltration permeate into the harmless treatment device, and remove residual heavy metals and antibiotics through special adsorption and electrocatalytic oxidation in sequence. S7. The harmless treated liquid is introduced into the biogas slurry concentration device and concentrated using a special anti-fouling reverse osmosis membrane with a concentration ratio greater than 3 and a membrane flux of 10-16 LMH. The concentrated liquid is used as a high-value-added liquid fertilizer, and the permeate is recycled for aquaculture rinsing. Among them, steps S1 to S7 are implemented through a monitoring and control module to achieve full-process signal acquisition and feedback regulation, enabling the processing system to achieve zero emissions.

2. A solid-liquid separation device for realizing the primary solid-liquid separation described in step S2 of claim 1 and the secondary solid-liquid separation described in step S3, characterized in that, It includes a main support (1), casters (2), a fixing plate (3), a feeding dish (4), a primary separation mechanism (5), an equipment cover plate (6), a connecting plate (7), a secondary separation mechanism (8), and a secondary filter inlet (851); the connecting plate (7) is provided with a flow port (71); The universal wheel (2) is installed at the bottom of the main support (1), the fixing plate (3) is fixedly installed on one side of the main support (1), the equipment cover plate (6) is covered above the main support (1) and fixedly connected to the main support (1), the feeding dish (4) is installed on the top of the equipment cover plate (6), and the connecting plate (7) is fixedly installed on the main support (1) and located between the primary separation mechanism (5) and the secondary separation mechanism (8); The primary separation mechanism (5) includes a motor (51), a rotating disk (52), a chain (53), a connecting disk (54), a main gear (55), a rotating gear (56), a first drive grooved wheel (57), a connecting rod (58), a second drive grooved wheel (59), a separation dish (510), a separation hole (511), a support frame (512), and a door (513). The motor (51) is fixedly installed on the top of the main support (1). The output shaft of the motor (51) is fixedly connected to the rotating disk (52). The rotating disk (52) is connected to the connecting disk (54) via the chain (53). The connecting disk (54) is coaxially fixedly connected to the main gear (55). The main gear (55) meshes with the rotating gear (56). 56) It is coaxially fixedly connected with the first drive groove wheel (57). The first drive groove wheel (57) overlaps the outer wall of the tail end of the separation dish (510). The first drive groove wheel (57) is fixedly connected to the second drive groove wheel (59) through the connecting rod (58). The second drive groove wheel (59) overlaps the outer wall of the front end of the separation dish (510). The support frame (512) is fixedly installed on the main support (1). The separation dish (510) is rotatably set inside the support frame (512). The separation dish (510) has a separation hole (511) on its cylindrical wall. The lower end of the feeding dish (4) is connected to the inlet end of the separation dish (510). The bin door (513) is openable and closable at the end of the separation dish (510) away from the feeding dish (4).

3. The solid-liquid separation device according to claim 2, characterized in that, The secondary separation mechanism (8) includes a reciprocating motor (81), a rotary gear (82), a gear ring (83), a separation chamber (831), an independent separation dish (84), a secondary separation hole (85), a stirring rod (86), a mounting plate (87), a cleaning hole (88), a discharge port (89), a discharge channel (810), and a lower discharge port (811). The secondary filter inlet (851) is fixedly installed at the end of the separation chamber (831) and communicates with the flow port (71). Multiple sets of independent separation dishes (84) are evenly distributed circumferentially inside the separation chamber (831). The inlet end of each independent separation dish (84) is connected to the secondary filter inlet (851) via a corrugated hose. Each independent separation dish (84) has a secondary separation hole (85) on its cylindrical wall. The stirring rod (86) is fixedly installed on the outer surface of each independent separation dish (84). The mounting plate (87) is fixedly installed at the end of the separation chamber (831). The mounting plate (87) has a cleaning hole (88). The cleaning hole (88) is connected to the interior of the independent separation dish (84). The end of the separation chamber (831) away from the secondary filter inlet (851) is provided with an outlet (89). The outlet (89) is connected to the discharge channel (810). The bottom of the discharge channel (810) is provided with a lower discharge port (811). The outer wall of the separation chamber (831) is fixedly fitted with a gear ring (83). The rotating gear (82) meshes with the gear ring (83). The reciprocating motor (81) is fixedly installed on the main support (1). The output shaft of the reciprocating motor (81) is fixedly connected to the rotating gear (82).

4. The solid-liquid separation device according to claim 2, characterized in that, In the first-stage separation mechanism (5), the motor (51) drives the main gear (55) to rotate via the rotating disk (52), chain belt (53) and connecting disk (54). The main gear (55) meshes with the rotating gear (56) for transmission. The rotating gear (56) drives the first drive groove wheel (57). The first drive groove wheel (57) is linked to the second drive groove wheel (59) via the connecting rod (58). The first drive groove wheel (57) and the second drive groove wheel (59) are respectively connected to the tail end and the front end of the separation dish (510) to form a synchronous drive structure at both ends.

5. The solid-liquid separation device according to claim 2, characterized in that, The support frame (512) is a cylindrical support structure, and the separation dish (510) is rotatably supported inside the support frame (512). The door (513) is located at the end of the separation dish (510) near the second drive groove wheel (59). After opening the door (513), large particles of impurities trapped inside the separation dish (510) can be cleaned and the separation holes (511) can be rinsed.

6. The solid-liquid separation device according to claim 3, characterized in that, In the secondary separation mechanism (8), each set of independent separation dishes (84) are evenly distributed around the separation chamber (831), and each independent separation dish (84) has a secondary separation hole (85) on its surface; the stirring rod (86) is set inside the separation chamber (831) and fixedly installed on the surface of each independent separation dish (84) to stir and prevent blockage of the feces passing through the secondary separation hole (85); The mounting plate (87) is installed at the end of the separation chamber (831). Multiple sets of cleaning holes (88) are provided on the mounting plate (87). Each cleaning hole (88) is connected to the corresponding independent separation dish (84). High-pressure clean water is injected through the cleaning hole (88) to backwash the inner wall of the independent separation dish (84) and the secondary separation hole (85).

7. The processing technology according to claim 1, characterized in that, The stirring system described in step S1 includes mechanical stirring, gas-liquid jet stirring, or gas aeration stirring. When gas-liquid jet stirring or gas aeration stirring is used, the gas source used includes biogas or nitrogen. The odor collected by the odor collection device is transported to the tail gas treatment device of the biogas utilization system or the matching odor treatment device for treatment.

8. The processing technology according to claim 1, characterized in that, The high-efficiency anaerobic fermentation device mentioned in step S4 is a UASB, UBF, or IC anaerobic reactor. The biogas produced by anaerobic digestion is purified and used for power generation, heating, or as a gas source for gas-liquid jet stirring and gas aeration stirring in step S1. The membrane separation and purification device mentioned in step S5 is a low-energy cross-flow ultrafiltration membrane, which adopts a closed-loop concentration and separation mode. The cross-flow velocity is 0.5-2 m / s, the membrane flux is 40-75 LMH, and the solid content of the concentrated liquid is greater than 4%. The concentrated liquid is returned to the secondary solid-liquid separation device in step S3 for further treatment.

9. The processing technology according to claim 1, characterized in that, The adsorbent in the special adsorption device mentioned in step S6 includes special resin, modified biochar, or nano-adsorption particles. The special adsorption device is divided into single-stage adsorption or two-stage adsorption. The wastewater from adsorption regeneration or backwashing is further removed by an electrocatalytic oxidation device or an electrocatalytic oxidation device combined with a precipitation device to remove heavy metals and antibiotics. The biogas slurry concentration device mentioned in step S7 is a special anti-fouling reverse osmosis membrane. The reverse osmosis membrane module is in the form of spiral wound or disc tube, with a concentration ratio greater than 3 and a membrane flux of 10-16 LMH. The water produced by the reverse osmosis membrane device is reused for flushing water in livestock and poultry farms, and the concentrated liquid from the reverse osmosis membrane device is used as liquid fertilizer for crop planting, algae cultivation, or soil improvement.

10. The processing method according to claim 1, characterized in that, The monitoring and control module includes a signal acquisition, signal feedback, and command feedback system; the real-time signal acquisition factors of the manure storage module and solid-liquid separation module include ammonia concentration, hydrogen sulfide concentration, aeration rate, sludge content, manure residue moisture content, and temperature; the real-time signal acquisition factors of the high-efficiency anaerobic fermentation module include COD concentration, VFA concentration, heavy metal concentration, and antibiotic concentration; the real-time signal acquisition factors of the membrane separation purification and biogas slurry concentration module include membrane flux, transmembrane pressure, ammonia nitrogen concentration, COD concentration, conductivity, and pH.

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