Method and device for solid-liquid separation of low-odor water soaked manure

Abstract

The invention discloses a solid-liquid separation method for low-odor water-soaked manure, which specifically comprises the following steps: acting on water-soaked manure with the water content of 80-99.9% by adopting an electrode plate with conductive and filtering effects, enabling charged large particles in the water-soaked manure to do directional movement towards one side under the action of an electric field, filtering and recovering a liquid phase through the electrode plate, and recycling the liquid phase through the electrode plate. Therefore, fine particulate matters with the particle size of more than 0.1 mu m in the blistered manure are efficiently separated in a low-odor manner; according to the method and the device disclosed by the invention, the fine particulate matters in the blister dung can be efficiently separated, the odor emission content in the treatment process is low, the content of separated liquid-phase pollutants is also greatly reduced, and the removal rates of COD, TP, ammonia nitrogen and turbidity are 75%, 80%, 20% and 90% or above.

Description

Technical Field

[0001] The invention belongs to the field of environmental engineering, and specifically relates to a method and a device that can effectively reduce odor emissions during the treatment of water-soaked feces and improve solid-liquid separation efficiency. Background Art

[0002] With the rapid development of agriculture and animal husbandry, the amount of blister manure produced is increasing day by day, and its treatment and resource utilization have become a major issue of current environmental protection. Blister manure contains a large amount of organic matter and nutrients. If it is not effectively treated, it is easy to cause water pollution, soil degradation and the spread of pests and diseases. Therefore, the development of efficient and economical blister manure solid-liquid separation technology is of great practical significance.

[0003] Traditional methods for treating water-soaked feces mainly include natural sedimentation, mechanical screening and chemical treatment. Although these methods can achieve solid-liquid separation to a certain extent, they often have the following shortcomings: Low separation efficiency: When treating blister feces containing fine particles and colloidal substances, the traditional methods have unsatisfactory separation effects, especially in the removal of fine particles, which often leads to low separation rates of solids and liquids; Odor generation problem: Most traditional solid-liquid separation methods are prone to odor volatilization during the separation process, especially during pretreatment or precipitation. This not only affects the working environment of on-site workers, but may also cause trouble to surrounding residents, increasing public resentment; Complex devices and high maintenance costs: Many existing devices have complex structures, inconvenient operations, and high maintenance costs under long-term operation, increasing production costs; Long processing time: In practical applications, many solid-liquid separation methods require a long processing time, which limits their application in large-scale blister feces treatment; Secondary pollution risk: Some chemical treatment methods may cause secondary pollution to the environment and should be used with caution; However, in existing studies, although some theoretical and experimental schemes have been proposed, there is still a lack of a systematic and economical low-odor blister feces solid-liquid separation device. Such a device needs to be able to effectively suppress the generation of odor while maintaining efficient separation. Therefore, it is particularly important to develop a method and device for solid-liquid separation of foamy feces that is both efficient and low in odor. Summary of the invention

[0004] In view of the problems existing in the prior art, the present invention provides a method for solid-liquid separation of low-odor foamy feces. The method uses an electrode plate with conductive and filtering functions to act on foamy feces with a moisture content of 80-99.9%. Under the action of the electric field, the charged large particles in the foamy feces are directed to move to one side, and the liquid phase is filtered and recovered by the electrode plate, thereby separating fine particles with a particle size greater than 0.1 μm in the foamy feces with high efficiency and low odor, thereby realizing solid-liquid separation.

[0005] The conductive material and the polymer binder are mixed at a mass ratio of 1 to 4:1, the mixture is evenly coated on the surface of the substrate filter plate or the substrate filter plate is immersed in the mixture, and after the substrate filter plate is fully absorbed, it is dried to obtain an electrode plate with a pore size of 0.01 to 10 μm and having conductive and filtering functions.

[0006] The conductive material is one of carbon-based materials, metal powder, and conductive polymers; the base filter plate is made of one of polyester, polypropylene, polyvinyl fluoride, and non-woven fabrics; and the polymer adhesive is polyvinyl alcohol or polyacrylic acid.

[0007] The carbon-based material is selected from graphene, carbon nanotubes, and activated carbon; the metal powder is selected from silver powder and copper powder; and the conductive polymer is selected from polyaniline, polypyrrole, and polyethylenedioxythiophene.

[0008] When preparing the electrode plate, an additive of 2-20% by volume of the mixture is added, and the additive is one or more of polyvinyl pyrrolidone and polyvinyl alcohol.

[0009] Another object of the present invention is to provide a device for completing the above-mentioned method of solid-liquid separation of low-odor foamy feces, which includes a shell, an open reaction chamber separated by two electrode plates in the shell, the two electrode plates are respectively connected to the positive and negative poles of the power supply, and the two sides of the reaction chamber are a cathode liquid phase collection chamber and an anode liquid phase collection chamber; an ultrasonic cleaning generator is arranged on the outside of the shell, and after the separation is completed, the cavitation effect of the ultrasonic wave is used to remove and precipitate fine particles attached to the inner surface of the membrane; a solid phase collection tank is arranged at the bottom of the reaction chamber, and a discharge port is opened on the solid phase collection tank; a movable bracket is installed at the bottom of the shell.

[0010] When the power supply is a DC power supply, the voltage is 1V~100V, and when the power supply is an AC power supply, the voltage is 5V~150V; applying DC or AC makes the charged fine particles move in a directional manner under the action of the electric field. Under DC, they migrate and adhere to one pole, and the liquid phase is filtered out from the filter plate of the other pole to the collection chamber, and then the conductive filter membrane electrode is cleaned by ultrasound for reciprocating use; under AC, the charged particles move back and forth between the two electrodes. When moving toward the anode, the liquid phase enters the collection chamber from the cathode filter membrane, and when moving toward the cathode, the liquid phase enters the collection chamber from the anode filter membrane. The two-pole collection chamber can separate the liquid phase at the same time under AC and is not easy to attach to the solid phase. At the same time, under the action of the electric field, pollutants in the water bubble manure such as total phosphorus, total nitrogen and COD will undergo decomposition reactions and electrodeposition reactions, achieving the effect of efficient solid-liquid separation while being able to remove soluble pollutants in the liquid phase.

[0011] The ultrasonic frequency of the ultrasonic cleaner is 20-200 kHz.

[0012] Advantages and technical effects of the present invention: 1. Efficient separation: This method is aimed at solid particles with a particle size greater than 1μm in water-filled feces. It uses the characteristics of electric field and conductive filter membrane to achieve efficient solid-liquid separation. It combines multiple separation technologies, such as electric field separation and mechanical screening, to improve the removal rate of fine particles and colloidal substances, ensuring high-quality solid and liquid products. 2. Low odor emission: This technology can effectively control odor emission during the treatment process, reduce the impact on the environment, and meet green environmental protection requirements; 3. Strong adaptability: The electric field type (DC or AC) can be adjusted according to needs, flexibly responding to the characteristics of different solid particles and improving the controllability of the separation effect.

[0013] 4. Reduce pollutant content: Under optimal conditions, the content of separated liquid pollutants (such as COD, TP, ammonia nitrogen) can be greatly reduced, which is helpful for environmental protection; 6. Combined process: It can be combined with other devices such as ultrasonic cleaners to form a synergistic effect, further improve separation efficiency and cleaning effect, optimize the design and operating conditions of the separation device, reduce energy consumption, improve economy, and ensure that while effectively treating watery feces, no unnecessary waste of resources is caused. Strengthen subsequent utilization: The separated solids and liquids can be used as fertilizers and soil conditioners to achieve the recycling of resources and reduce the environmental burden. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 is a device structure diagram of the device of the present invention; In the figure: 1-power supply; 2-positive electrode plate; 3-negative electrode plate; 4-cathode liquid phase collecting chamber; 5-anode liquid phase collecting chamber; 6-reaction chamber; 7-ultrasonic cleaning generator; 8-solid phase collecting tank; 9-movable bracket; 10-discharge port. DETAILED DESCRIPTION

[0015] The present invention is further described in detail below through specific embodiments, but the protection scope of the present invention is not limited to the contents described above; The device used in the following embodiments includes a housing, in which an open reaction chamber 6 is separated by two electrode plates, the positive electrode plate 2 and the negative electrode plate 3 are respectively connected to the positive and negative electrodes of the power supply 1, and the two sides of the reaction chamber are a cathode liquid phase collection chamber 4 and an anode liquid phase collection chamber 5; an ultrasonic cleaning generator 7 is arranged on the outside of the housing, a solid phase collection tank 8 is arranged at the bottom of the reaction chamber, a discharge port 10 is opened on the solid phase collection tank, and a movable bracket 9 is arranged at the bottom of the housing; Example

[0016] 1. Mix graphene powder and polyvinyl alcohol in a mass ratio of 4:1, add 5% polyvinyl pyrrolidone (PVP) by volume of the mixture, stir evenly to form a slurry, and evenly coat the slurry on the polyester substrate filter plate. The coating thickness is controlled within 1mm. Place the coated filter plate in an oven and dry it at 70°C for 4 hours to obtain an electric filter plate with an aperture of 1μm; 2. The above device is used to treat blister manure from a pig farm with a moisture content of 98%. 1 / 2 of the volume of the blister manure is added to the reaction chamber 6. The DC power supply is started, the voltage is set to 40V, and the power is continuously turned on for 2 hours. The negatively charged particles in the blister manure move toward the positive electrode plate 2. Under the action of the electric field, the fine particles move in a directional manner and are intercepted by the positive electrode plate. The large granular particles are deposited in the solid phase collection tank 8. The liquid phase components are filtered through the negative electrode plate 3 and enter the cathode liquid phase collection tank 4. After the liquid volume is greater than the volume of the liquid phase collection tank, it overflows out of the device for recovery. After the reaction is balanced, the ultrasonic cleaner 7 is turned on to ultrasonically clean the particles attached to the electrode plate at 30 kHz to remove the fine particles adsorbed on the surface and enter the solid phase collection tank and be discharged from the discharge port 10. The separated liquid phase COD removal rate is 86%, the ammonia nitrogen removal rate is 21%, the TP removal rate is 82%, and the turbidity removal rate is 95%. The movable bracket 9 can adapt to various scenarios and move the device according to actual production needs. Example

[0017] The device structure of this embodiment is the same as that of embodiment 1. The above device is used to treat the water bubble manure in the pig breeding farm. Specifically, an AC power supply is used. After the water bubble manure enters the reaction chamber, the two electrode plates are connected to the AC power supply, the voltage is set to 20 V, the frequency is set to 50 Hz, and the cycle of the alternating electric field is maintained at 10s during operation. Under the influence of the alternating electric field, the charged particles move back and forth between the positive electrode plate and the negative electrode plate, and the liquid phase continuously enters each liquid phase collection chamber during the alternating movement of the positive electrode plate and the negative electrode plate; after 3 hours of reaction, the separation reaches equilibrium, and the ultrasonic cleaning generator is started, the frequency is set to 30 kHz, the power is 150 W, and it lasts for 15 minutes to ensure that the surface of the electrode plate is fully cleaned. This embodiment achieves efficient solid-liquid separation with an alternating electric field, and the COD removal rate of pollutants in the liquid phase reaches 75%, the ammonia nitrogen removal rate reaches 33%, the TP removal rate reaches 88%, and the turbidity removal rate reaches 93%. The solid phase is not easy to adhere, ensuring long-term stable operation. Example

[0018] 1. Mix silver powder and polyacrylic acid in a mass ratio of 3:2, add 10% polyvinyl alcohol (PVA) by volume of the mixture, stir well to form a slurry, and evenly coat the slurry on the polypropylene substrate filter plate with a coating thickness of less than 1.5 mm. Dry the coated filter plate at 55°C for 5 hours to obtain an electric filter plate with a pore size of 0.5 μm; 2. The above device was used to treat farmers' own water-filled manure. Water-filled manure (water content of 95%) was added to the reaction chamber, accounting for 2 / 3 of the reaction chamber volume. The DC power supply was started, the voltage was set to 30V, and the power was continuously turned on for 3 hours. During the treatment process, the negatively charged particles in the water-filled manure moved toward the positive electrode plate, while the liquid phase components entered the cathode liquid phase collection tank through the negative electrode plate. When the reaction reached equilibrium, the ultrasonic cleaning generator was started, the frequency was set to 25 kHz, the power was 100 W, and the cleaning lasted for 20 minutes, in order to remove the dirt and fine particles adsorbed on the surface of the electric filter plate and improve the reuse efficiency of the electric filter plate. The liquid phase COD removal rate after separation reached 80%; the ammonia nitrogen removal rate reached 28%; the TP removal rate reached 85%; and the turbidity removal rate reached 90%.

Claims

1. A method for solid-liquid separation of low-odor foamy feces, characterized in that: Electrode plates with conductive and filtering functions are used to act on foamed feces with a moisture content of 80~99.9%. Under the action of the electric field, the charged large particles in the foamed feces are directed to move to one side, and the liquid phase is filtered and recovered through the electrode plates, thereby separating fine particles with a particle size greater than 0.1μm in the foamed feces with high efficiency and low odor.

2. The method for solid-liquid separation of low-odor foamy feces according to claim 1, characterized in that: The conductive material and the polymer binder are mixed at a mass ratio of 1 to 4:1, and the mixture is evenly coated on the surface of the substrate filter plate or the substrate filter plate is immersed in the mixture. After the substrate filter plate is fully absorbed, it is dried to obtain an electrode plate with a pore size of 0.01 to 10 μmm and having conductive and filtering functions.

3. The method for solid-liquid separation of low-odor foamy feces according to claim 2, characterized in that: The conductive material is one of carbon-based materials, metal powder, and conductive polymers; the base filter plate is made of one of polyester, polypropylene, polyvinyl fluoride, and non-woven fabrics; and the polymer adhesive is polyvinyl alcohol or polyacrylic acid.

4. The method for solid-liquid separation of low-odor foamy feces according to claim 3, characterized in that: The carbon-based material is selected from graphene, carbon nanotubes, and activated carbon; the metal powder is selected from silver powder and copper powder; and the conductive polymer is selected from polyaniline, polypyrrole, and polyethylenedioxythiophene.

5. The method for solid-liquid separation of low-odor foamy feces according to claim 2, characterized in that: An additive is also added in an amount of 2-20% by volume of the mixture, wherein the additive is one or more of polyvinyl pyrrolidone and polyvinyl alcohol.

6. A device for carrying out the method for solid-liquid separation of low-odor foamy feces as claimed in claim 1, characterized in that: It includes a shell, in which an open reaction chamber is separated by two electrode plates, the two electrode plates are respectively connected to the positive and negative poles of the power supply, and the two sides of the reaction chamber are a cathode liquid phase collection chamber and an anode liquid phase collection chamber; an ultrasonic cleaning generator is arranged on the outside of the shell, a solid phase collection tank is arranged at the bottom of the reaction chamber, and a discharge port is opened on the solid phase collection tank.

7. The device according to claim 6, characterized in that: A movable bracket is arranged at the bottom of the shell.

8. The device according to claim 6, characterized in that: When the power supply is a DC power supply, the voltage is 1V~100V, and when the power supply is an AC power supply, the voltage is 5V~150V.

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