Sectional type flocculation method and device for livestock and poultry manure

Abstract

The invention relates to the technical field of feces treatment, and discloses a livestock and poultry feces sectional type flocculation method and device.The livestock and poultry feces sectional type flocculation method comprises the steps of pretreatment, coagulation, flocculation growth, densification and separation, specifically, firstly, livestock and poultry feces are subjected to solid-liquid separation to obtain a stock solution, polyaluminum chloride, strong acid modified vermiculite (a flocculant A) and strong base modified montmorillonite (a flocculant B) are sequentially added, and the stock solution is subjected to solid-liquid separation; dense large flocs are formed in cooperation with gradient stirring, and supernate and precipitates are separated after standing. The device comprises a flocculation precipitator tank body, a water inlet pipeline, a variable-frequency stirring motor, a flocculant adding control box and the like, an anti-blocking structure is arranged at the bottom end in the tank, and a heating structure is arranged on an outer support. Through sectional flocculation and intelligent control, the excrement treatment efficiency is improved, the subsequent load is reduced, and sediments can be recycled. The progressive flocculation with strong current neutralization, adsorption, bridging, strong netting and compaction is realized through the sectional feeding design of polyaluminum chloride, strong acid modified vermiculite and strong base modified montmorillonite and in combination with gradient stirring control.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of fecal treatment, in particular to a livestock and poultry fecal segment type flocculation method and device. BACKGROUND

[0002] With the rapid development of large-scale and intensive livestock and poultry breeding industry in China, the amount of livestock and poultry feces has increased dramatically, and its efficient treatment and resource utilization have become a key environmental problem to be solved. Livestock and poultry feces, which contain high concentrations of organic matter, nitrogen and phosphorus nutrients, suspended solids (SS) and pathogenic microorganisms, can easily cause water eutrophication, soil pollution, air odor and disease transmission if not properly treated, threatening water environment safety and public health.

[0003] At present, the state encourages livestock and poultry feces to be returned to the field nearby, but most enterprises, especially large-scale intensive farms, lack sufficient land. If all the livestock and poultry feces are returned to the field nearby, nearly ten thousand mu of contiguous planting land needs to be rented, which greatly increases the cost of land transfer and enterprise operation cost. Therefore, standard discharge or partial standard discharge is still the main choice of most intensive breeding enterprises at this stage.

[0004] Livestock and poultry feces, as organic wastewater with complex composition and extremely high pollutant concentration, contain high concentrations of suspended solids (SS), colloidal and dissolved organic matter (represented by COD and BOD), high content of nitrogen and phosphorus nutrients, various salts, pathogenic microorganisms and residual veterinary drugs or heavy metals. It has the characteristics of solid-liquid mixing, high viscosity, strong stability and significant fluctuation of properties with breeding species, feed and manure cleaning method, which makes the treatment extremely difficult: high concentration of organic matter and suspended solids increases the treatment load, colloidal and fine particles are difficult to separate effectively, nitrogen and phosphorus removal requires targeted process, and the composition of single treatment technology is unstable, poor in adaptability, and easy to produce odor and secondary pollution during treatment. Its efficient, stable and low-cost pretreatment (especially solid-liquid separation) is the key bottleneck for subsequent harmless and resource utilization.

[0005] Flocculation technology is widely used for solid-liquid separation pretreatment of livestock and poultry feces due to its simple operation, high treatment efficiency and relatively low cost. The mainstream methods include chemical flocculation, biological flocculation, electro-flocculation, magnetic flocculation and derivative combination technology, but all have disadvantages: the commonly used PAM crystals in chemical flocculation are toxic, the sludge microplastic content is high and cannot be composted; biological flocculation and electro-flocculation have harsh conditions, long cycle and high cost; the magnetic powder in magnetic flocculation is difficult to recover, and the operation cost is high.

[0006] In view of this, the purpose of the present application is to provide a livestock and poultry fecal segment type flocculation method and device to solve the problems in the prior art. SUMMARY

[0007] In view of the deficiencies of the prior art, the present application provides a livestock and poultry manure segmented flocculation method and device, which solves the problems of high cost of nearby land for returning to field, low efficiency of existing flocculation technology and large subsequent treatment load in the existing livestock and poultry manure treatment.

[0008] To achieve the above object, the present application is realized by the following technical solutions: A livestock and poultry manure segmented flocculation method and device, comprising the following steps: S1, pretreatment step: solid-liquid separation is performed on livestock and poultry manure to obtain a manure raw liquid to be treated, and the manure raw liquid is sent into a flocculation sedimentation tank through a water inlet pipeline; S2, coagulation step: polyaluminum chloride is added to the manure raw liquid through a flocculant adding control box via a flocculant adding pipeline, and a variable frequency stirring motor is started at the same time, and the output end of the variable frequency stirring motor is connected to a rotating rod to drive an impeller to stir in the first stage, so that the colloidal particles in the manure are destabilized to form small flocs; S3, flocculation growth step: then, inorganic flocculant A as a flocculation core is added through the flocculant adding control box, and the impeller is driven by the variable frequency stirring motor to stir in the second stage, so that the small flocs are gradually increased through adsorption bridging; S4, densification step: then, inorganic flocculant B for enhancing the density of flocs is added through the flocculant adding control box, and the impeller is driven by the variable frequency stirring motor to stir in the third stage, so that dense and easily settled large-size flocculation bodies are formed; Wherein, the inorganic flocculant A is strong acid modified vermiculite, and the inorganic flocculant B is strong alkali modified montmorillonite.

[0009] Preferably, after the S4 step, a separation step is further included: the stirring of the variable frequency stirring motor is stopped, the large-size flocculation bodies formed are settled, the supernatant is separated by starting a decanter connected to a supernatant outlet pipeline, and the sediment is separated by opening a valve arranged on a sediment outlet.

[0010] Preferably, the variable frequency stirring motor is controlled by a controller integrated in the flocculant adding control box, so that the stirring speed of the first stage stirring is not greater than 600 r / min, the stirring speed of the second stage stirring is not greater than 1000 r / min and is higher than the stirring speed of the first stage stirring. The stirring speed of the third stage stirring is the same as the stirring speed of the second stage stirring.

[0011] Preferably, the strong acid modified vermiculite is prepared by modifying vermiculite with a sulfuric acid solution with a concentration of 1-4 mol / L at 80-100℃ for 2-4 hours.

[0012] Preferably, the strong base modified montmorillonite is prepared by modifying montmorillonite with a sodium hydroxide solution having a concentration of 0.5-2 mol / L at 60-90°C for 1-3 hours.

[0013] The livestock and poultry manure section type flocculation device, including flocculation precipitator jar body, the flocculation precipitator jar body outside one side is provided with water inlet pipeline, the water inlet pipeline one end is connected with flocculation precipitator jar body inside, the water inlet pipeline other end is provided with feed hopper, the flocculation precipitator jar body upper portion is fixedly installed with variable frequency stirring motor, the variable frequency stirring motor output is fixedly connected with rotating rod, the rotating rod outside is provided with multiple stirring impellers, the flocculation precipitator jar body upper portion one side is also fixedly installed with flocculating agent dosing control box, the flocculating agent dosing control box one side is fixedly connected with flocculating agent dosing pipeline, the flocculating agent dosing pipeline is connected with flocculation precipitator jar body inside, the flocculation precipitator jar body outside is provided with flocculation precipitator outer support; The flocculation precipitator jar body inside bottom end is provided with anti-blocking structure, which is used to place the treated material to accumulate at the bottom, and the flocculation precipitator outer support upper portion is also fixedly installed with heating structure, which is used to heat the inside of the flocculation precipitator jar body, so that the material is fused.

[0014] Preferably, the flocculation precipitator jar body is also provided with supernatant outlet pipe for discharging supernatant, the flocculation precipitator jar body bottom end is provided with sediment discharge outlet for discharging sediment, the sediment discharge outlet outside is provided with valve, the supernatant outlet pipe one end is connected with decanter, the decanter is used to skim supernatant from supernatant liquid surface, and the decanter is lifted by decanter electric control telescopic pipe.

[0015] Preferably, the anti-blocking structure includes filter plate fixedly installed at the bottom end inside the flocculation precipitator jar body, the rotating rod bottom end is fixedly installed with multiple cleaning brushes, multiple cleaning brushes are arranged above the filter plate, and multiple cleaning brushes one side are all upwardly inclined and installed with turnover plates.

[0016] Preferably, the heating structure includes multiple heating elements fixedly installed on the flocculation precipitator outer support upper portion, multiple heating elements upper portions are all provided with heat conducting rods, the flocculation precipitator jar body outside is provided with heat conducting ring, multiple heat conducting rods are all connected with the heat conducting ring, and the flocculation precipitator jar body outside is provided with temperature sensor.

[0017] Preferably, the flocculating agent dosing control box is integrated with controller, and the controller is pre-set with dosing program and stirring program corresponding to the coagulation step, flocculation growth step and densification step.

[0018] The present application provides a livestock and poultry manure section type flocculation method and device, which has the following beneficial effects: 1. The present application realizes the progressive flocculation of strong electricity neutralization adsorption bridging strong net capture compaction by the sectional type adding design of polyaluminum chloride, strong acid modified vermiculite and strong alkali modified montmorillonite, combined with gradient stirring control, wherein the polyaluminum chloride first neutralizes the colloidal charge to form small flocs, the strong acid modified vermiculite further compacts the flocs, and reduces the load of subsequent anaerobic digestion or aerobic treatment, solving the problems of low processing efficiency and incomplete pollutant removal of traditional technology.

[0019] 2. The polyaluminum chloride, strong acid modified vermiculite and strong alkali modified montmorillonite used in the present application are all non-toxic inorganic materials, the heavy metal content of the precipitate produced by flocculation can be directly added to rice chaff, fungus chaff and other auxiliary materials for composting, or further processed into organic fertilizer after plate and frame pressure filtration, realizing the closed loop utilization of manure treatment precipitate resources, not only solving the pain point of sludge difficult to compost in traditional technology, but also creating additional economic benefits for farms, reducing solid waste disposal cost, and meeting the policy guidance of livestock and poultry manure resource utilization.

[0020] 3. The present application integrates a controller with a preset program, which can automatically control the flocculant dosage and stirring speed without frequent manual intervention; the anti-blocking structure at the bottom of the tank drives the cleaning brush to clean the filter plate, and the turnover plate disperses the caked precipitate, avoiding blockage of the discharge port; the heating structure on the outer support drives the heating element through the temperature sensor, ensuring the flocculation activity in low temperature environment, greatly prolonging the continuous operation time of the equipment, reducing the frequency of shutdown cleaning, and reducing the comprehensive operation cost, balancing the stability and economy of the equipment, especially suitable for large-scale manure treatment needs of intensive farms. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 is a perspective view of the present application; Figure 2 is a schematic view of the internal structure of the present application; Figure 3 is a schematic view of the stirring structure of the present application; Figure 4 is a schematic view of the sectional flocculation main process sequence control algorithm flow of the present application; Figure 5 is a schematic view of the PID constant temperature closed loop feedback control algorithm flow of the present application.

[0022] Wherein, 1, water inlet pipeline; 2, flocculation sedimentation tank body; 3, variable frequency stirring motor; 4, flocculant dosing control box; 5, flocculant dosing pipeline; 6, stirring impeller; 7, decanter; 8, decanter electric control telescopic pipe; 9, supernatant outlet pipe; 10, flocculation sedimentation tank outer support; 11, sediment discharge port; 12, feed hopper; 13, rotating rod; 14, anti-blocking structure; 1401, filter plate; 1402, cleaning brush; 1403, turnover plate; 15, heating structure; 1501, heating element; 1502, heat conducting rod; 1503, heat conducting ring; 1504, temperature sensor; 16, controller; 17, valve. DETAILED DESCRIPTION

[0023] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0024] Please refer to the accompanying drawings of the present application Figure 1 - the accompanying drawings of the present application Figure 5 The embodiments of the present application provide a livestock and poultry manure segmented flocculation method and device, including the following steps: S1, pretreatment step: solid-liquid separation is performed on livestock and poultry manure to obtain raw manure liquid to be treated, and the raw manure liquid is sent into the flocculation sedimentation tank body 2 through the water inlet pipeline 1; S2, coagulation step: polyaluminum chloride is added to the raw manure liquid through the flocculant dosing control box 4 via the flocculant dosing pipeline 5, and at the same time, the variable frequency stirring motor 3 is started, and the rotating rod 13 connected to the output end of the variable frequency stirring motor 3 drives the stirring impeller 6 to perform first-stage stirring, so that the colloidal particles in the manure are destabilized to form small floc; S3, flocculation growth step: subsequently, inorganic flocculant A serving as a flocculation core is added through the flocculant dosing control box 4, and the stirring impeller 6 is driven by the variable frequency stirring motor 3 to perform second-stage stirring, so that the small floc is gradually increased through adsorption bridging; S4, densification step: then, inorganic flocculant B for enhancing the denseness of the floc is added through the flocculant dosing control box 4, and the stirring impeller 6 is driven by the variable frequency stirring motor 3 to perform third-stage stirring, so that large-size flocculation bodies which are dense and easy to settle are formed; Among them, the inorganic flocculant A is strong acid modified vermiculite, and the inorganic flocculant B is strong alkali modified montmorillonite.

[0025] The present embodiment provides a preparation method of strong acid modified vermiculite, and the specific steps are as follows: Raw material pretreatment: Select natural vermiculite, crush it with a pulverizer and pass it through a 200-mesh sieve. Take the powder that passes through the sieve as the raw material.

[0026] Acid modification reaction: Take 100 g of the vermiculite powder pretreated above and place it in a reaction kettle. Add 500 mL of a sulfuric acid (H2SO4) solution with a concentration of 2.5 mol / L at a solid-liquid ratio of 1:5 (g / mL). Turn on mechanical stirring (300 r / min) to uniformly disperse the vermiculite powder in the acid solution.

[0027] Constant temperature treatment: Raise the temperature of the reaction system to 90°C and keep it at this temperature for 3 hours. During this process, the sulfuric acid reacts with the interlayer metal ions of the vermiculite, opening up the channels and increasing the active sites through acid etching.

[0028] Separation and washing: After the reaction is complete, stop heating and stirring, and wait for the mixture to cool to room temperature. Use a vacuum filter press to separate the solid and liquid, and collect the filter cake. Wash the filter cake repeatedly with deionized water until the pH value of the filtrate is neutral (pH 6.5-7.0) to remove the residual free acid and reaction byproducts.

[0029] Drying and finished product: Place the washed filter cake in a forced air drying oven and dry it at 105°C for 12 hours until the weight is constant. Take out the dried material, grind it, and pass it through a 200-mesh sieve again to obtain the inorganic flocculant A (strong acid modified vermiculite).

[0030] This example provides a method for preparing a strong alkali modified montmorillonite, and the specific steps are as follows: Raw material pretreatment: Select calcium-based montmorillonite, crush it with a pulverizer and pass it through a 200-mesh sieve. Take the powder that passes through the sieve as the raw material.

[0031] Alkali modification reaction: Take 100 g of the montmorillonite powder pretreated above and place it in a three-necked flask. Slowly add 1000 mL of a sodium hydroxide (NaOH) solution with a concentration of 1.0 mol / L at a solid-liquid ratio of 1:10 (g / mL). Turn on magnetic stirring with a stirring speed of 400 r / min to prevent the montmorillonite from swelling and clumping after absorbing water.

[0032] Constant temperature treatment: Place the three-necked flask in a water bath and raise the temperature to 80°C. Keep it at this temperature for 2 hours. This process uses a strong alkali solution to etch the montmorillonite lattice, changing its interlayer spacing and surface charge distribution.

[0033] Separation and washing: After the reaction is complete, use a centrifuge to separate the suspension at a speed of 3000 r / min and discard the supernatant. Resuspend the precipitate with deionized water, centrifuge again, and repeat the resuspension and centrifugation washing steps 3-5 times until the pH value of the supernatant is close to neutral (pH 7.0-7.5).

[0034] Drying and Finishing: The washed solid material is spread on enamel trays and dried in a drying oven at 105°C for 10 hours. The dried material is ground in a grinder and sieved through a 200-mesh screen to obtain the inorganic flocculant B (strong base modified montmorillonite).

[0035] Specifically, S1, the pretreatment step: This step is the starting point of the whole process. First, the original livestock and poultry manure is subjected to solid-liquid separation to remove the larger solid impurities, thereby obtaining the subsequent treatment of the manure stock solution with good fluidity. Subsequently, the stock solution is pumped into the flocculation sedimentation tank 2 as the core reaction container through the water inlet pipe 1. To prevent the liquid from overflowing during the subsequent stirring process, the feeding height is usually controlled at three-quarters of the total volume of the tank.

[0036] S2, the coagulation step: This is the starting stage of the flocculation process. The polyaluminum chloride PAC is accurately added to the manure stock solution in the tank through the flocculant dosing control box 4 and the pipe 5. As a highly efficient inorganic coagulant, polyaluminum chloride releases a large number of positive charge ions that quickly neutralize the negatively charged colloidal particles in the manure. The variable frequency stirring motor 3 drives the stirring impeller 6 to perform the first stage of high-speed stirring, aiming to fully mix the reagent with the manure stock solution in a short time, ensuring that all colloidal particles can contact with the coagulant, thereby quickly forming uniform small flocs.

[0037] S3, the flocculation growth step: In this stage, the inorganic flocculant A, i.e., strong acid modified vermiculite, which serves as the flocculation core, is continuously added through the flocculant dosing control box 4. The small flocs formed in the S2 step are connected and aggregated, allowing their volume to gradually increase. At the same time, the stirring motor enters the second stage of stirring mode, and its speed changes to meet the needs of flocculation growth, ensuring that the flocs can fully collide and combine, while avoiding excessive shear force that breaks them.

[0038] S4, the densification step: To make the flocs more easily settle, the inorganic flocculant B, i.e., strong base modified montmorillonite, which enhances the density, is added. The strong base modified montmorillonite can quickly wrap around the already grown flocs, filling the gaps between the flocs and enhancing their structural strength and density. The stirring motor enters the third stage of stirring, finally forming large-sized flocculation bodies with larger size, tight structure, and increased specific gravity, laying a solid foundation for the subsequent rapid solid-liquid separation.

[0039] After the S4 step, there is also a separation step: stop the stirring of the variable frequency stirring motor 3, allow the formed large-sized flocculation bodies to settle, and separate the supernatant by starting the decanter 7 connected to the supernatant outlet pipe 9 to obtain the supernatant, and by opening the valve 17 set on the sediment outlet 11 to obtain the sediment. Specifically, this step starts after the compaction step S4 is completed and the variable frequency stirring motor 3 is completely stopped. First, a static settling phase is entered, allowing the large-size, high-density flocculation formed in S4 to naturally settle under gravity and separate from the relatively clear liquid above.

[0040] After settling is complete, the supernatant is separated. This is done by activating the decanter 7 connected to the supernatant outlet pipe 9. The decanter 7 slowly descends at a speed not greater than 10 cm / min through the electrically controlled telescopic pipe 8, skimming the supernatant from the liquid surface to avoid disturbing the sediment at the bottom. When the turbidity probe on the decanter contacts the sediment layer, it automatically stops descending, ensuring complete separation.

[0041] After the supernatant is discharged, the sediment is separated. This is done by programming the opening of the valve 17 provided at the sediment outlet 11 at the bottom of the tank. At this time, the anti-clogging structure 14 at the bottom of the tank is activated, slowly rotating the rotating rod 13 and the cleaning brush 1402 and turning plate 1403 to break up and clean the possibly hardened sediment to the outlet, ensuring smooth discharge without clogging.

[0042] The variable frequency stirring motor 3 is controlled by the controller 16 integrated in the flocculant dosing control box 4, so that the stirring speed in the first stage is not greater than 600 r / min, and the stirring speed in the second stage is not greater than 1000 r / min and higher than the stirring speed in the first stage; The stirring speed in the third stage is the same as the stirring speed in the second stage; Specifically, the precise control of this gradient stirring is realized by the controller 16 integrated in the flocculant dosing control box 4. The controller 16 has pre-set automatic programs corresponding to each step, which can accurately control the variable frequency stirring motor 3 to output different speeds in different stages.

[0043] First stage coagulation stirring: the stirring speed is set to not greater than 600 r / min. This is a relatively high speed, which aims to produce intense hydraulic turbulence to promote rapid and uniform dispersion of the reagent throughout the water body, fully contact with the pollutant particles, and achieve rapid destabilization.

[0044] Second stage flocculation growth stirring: the stirring speed is increased to not greater than 1000 r / min, and must be higher than the speed in the first stage. This is to provide more collision probability for adsorption bridging, accelerating the aggregation and growth of small flocculation.

[0045] Third stage compaction stirring: the stirring speed remains the same as the second stage, not greater than 1000 r / min. Maintaining a high speed helps the quick wrapping and compaction of the flocculation by the modified montmorillonite, forming a tight structure.

[0046] The strong acid modified vermiculite is prepared by using a sulfuric acid solution with a concentration of 1-4 mol / L to modify at 80-100°C for 2-4 hours.

[0047] The strong alkali modified montmorillonite is prepared by using a sodium hydroxide solution with a concentration of 0.5-2 mol / L to modify at 60-90°C for 1-3 hours.

[0048] The livestock manure section type flocculation device, including flocculation sedimentation tank body 2, the outside one side of flocculation sedimentation tank body 2 is provided with water inlet pipeline 1, and one end of water inlet pipeline 1 is connected with the inside of flocculation sedimentation tank body 2, and the other end of water inlet pipeline 1 is provided with feeding hopper 12, and the upper portion of flocculation sedimentation tank body 2 is fixedly installed with variable frequency stirring motor 3, and the output end of variable frequency stirring motor 3 is fixedly connected with rotating rod 13, and the outside of rotating rod 13 is provided with multiple stirring impellers 6, and the upper portion of one side of flocculation sedimentation tank body 2 is also fixedly installed with flocculant dosing control box 4, and one side of flocculant dosing control box 4 is fixedly connected with flocculant dosing pipeline 5, and flocculant dosing pipeline 5 is connected with the inside of flocculation sedimentation tank body 2, and the outside of flocculation sedimentation tank body 2 is provided with flocculation sedimentation tank outer support 10; the inside bottom end of flocculation sedimentation tank body 2 is provided with anti-blocking structure 14, which is used for placing the treated materials to be accumulated at the bottom, and the upper portion of flocculation sedimentation tank outer support 10 is also fixedly installed with heating structure 15, which is used for heating the inside of flocculation sedimentation tank body 2, so that the materials are fused. The upper portion of flocculation sedimentation tank body 2 is also provided with supernatant outlet pipe 9 for discharging supernatant, and the bottom end of flocculation sedimentation tank body 2 is provided with sediment outlet 11 for discharging sediments, and the outside of sediment outlet 11 is provided with valve 17, and one end of supernatant outlet pipe 9 is connected with decanter 7, and decanter 7 is used for skimming supernatant from the supernatant surface, and decanter 7 is lifted through decanter electric control telescopic pipe 8. Anti-blocking structure 14 includes filter plate 1401 fixedly installed at the inside bottom end of flocculation sedimentation tank body 2, multiple cleaning brushes 1402 fixedly installed at the bottom end of rotating rod 13, multiple cleaning brushes 1402 are all arranged above filter plate 1401, and multiple cleaning brushes 1402 are all upwardly inclinedly installed with turnover plates 1403 at one side. Heating structure 15 includes multiple heating elements 1501 fixedly installed at the upper portion of flocculation sedimentation tank outer support 10, multiple heating rods 1502 are all arranged at the upper portion of multiple heating elements 1501, flocculation sedimentation tank body 2 is provided with heat conduction ring 1503 at the outside, multiple heating rods 1502 are all connected with heat conduction ring 1503, and flocculation sedimentation tank body 2 is provided with temperature sensor 1504 at the outside. Flocculant dosing control box 4 is integrated with controller 16, and controller 16 is pre-set with dosing program and stirring program corresponding to coagulation step, flocculation growth step and densification step.

[0049] Specifically, this invention provides a highly efficient and automated segmented flocculation device for livestock and poultry manure, whose core advantage lies in an intelligent control system integrating advanced control algorithms. The device centers on a flocculation sedimentation tank 2 that integrates reaction and sedimentation, and executes physical and chemical processes through components such as a variable frequency stirring motor 3 and a flocculant dosing control box 4. The core algorithm built into the device is mainly reflected in two aspects. First, a segmented time-series and parameter-coordinated control algorithm precisely governs the entire flocculation process. The controller 16 strictly follows a preset time sequence, instructing the flocculant dosing control box 4 to add specific agents in the three stages of coagulation, flocculation growth, and densification, and simultaneously outputs different frequency signals to the variable frequency stirring motor 3 to achieve gradient stirring. This process strictly follows a slow-to-fast speed-up logic, i.e., the stirring speed in the first stage... r / min, the second stage growth rate reached ,satisfy and r / min, the third stage maintains .

[0050] The PID-based isothermal valve-loop reaction control algorithm aims to precisely regulate the reaction temperature. The controller 16 continuously monitors the reactant temperature via temperature sensor 1504. and the set target temperature Compare the two and calculate the error between them in real time: ; in, Indicates time Error value at time, This indicates the set target temperature. This indicates the current actual temperature.

[0051] The controller 16 is based on this error The classic PID control algorithm (i.e., proportional-integral-derivative control) is used to intelligently adjust the power of the heating element. The complete expression for its calculation is: ; in, Indicates time Real-time control output, In time Error value at time, Proportional gain constant, Integral gain constant, Differential gain constant, Indicates from time 0 to Error accumulation, Indicates error Rate of change over time.

[0052] Through this algorithm, the controller 16 can predict the temperature change trend, effectively suppress the temperature overshoot and fluctuation, and smoothly and accurately maintain the reaction system in the optimal temperature range, thereby ensuring the stability and efficiency of the flocculation reaction. In addition, the controller 16 also contains a set of anti-clogging cooperative algorithm. When discharging sludge, it first instructs the variable frequency stirring motor 3 to rotate at low speed to start the cleaning brush 1402 in the anti-clogging structure 14 to stir up the precipitate, and then opens the valve 17, through the cooperation of the actions, solves the problem of high solid content material blocking the outlet.

[0053] In this embodiment, the preparation method of inorganic flocculant A is as follows: Preparation method of inorganic flocculant A: The appearance of the agent is yellow-white particles, which is prepared by ultrasonic-microwave synergistic strengthening technology, and the specific steps are as follows: (1) Preparation of precursor: mix the pre-dried (80-100℃, 30-60min) ferrous sulfate and iron sulfate powder according to the molar ratio of 1.5:1. First, dissolve ferrous sulfate in ultrapure water containing 0.1-0.3% ascorbic acid, then dissolve iron sulfate in ultrapure water containing 0.05-0.15% hydroxyethylidene diphosphonic acid (structure directing agent). Mix them after ultrasonic treatment at 200-400W. 2+ :Fe 3+ Molar ratio 1.5:1. First, dissolve ferrous sulfate in ultrapure water containing 0.1-0.3% ascorbic acid, then dissolve iron sulfate in ultrapure water containing 0.05-0.15% hydroxyethylidene diphosphonic acid (structure directing agent). Mix them after ultrasonic treatment at 200-400W.

[0054] (2) Ultrasonic-microwave synergistic hydrolysis: place the mixed solution in a composite reactor. Turn on the ultrasonic (20-40kHz, 300-600W) and microwave (2450MHz, 500-1000W) and heat up to 65-75℃ at 5℃ / min. Oxygen bubbles (<100μm) are introduced for in-situ oxidation until the Fe 2+ conversion rate reaches 30-50%.

[0055] (3) Intelligent pH gradient control polymerization: use intelligent pH feedback system to add composite alkali agent (NaOH+Na2CO3+ a small amount of polyacrylamide). Control pH to rise in three stages: 2.5-3.0→3.5-4.0→3.8-4.3. At the same time, increase the microwave power to 800-1200W (pulse mode) and the ultrasonic power to 400-800W, the temperature to 80-95℃, and the polymerization time to 1.5-3 hours.

[0056] (4) Frequency conversion ripening and separation drying: stop heating, carry out frequency conversion ultrasonic ripening (20-60 kHz period change) at 70-80 DEG C, and add sodium silicate stabilizer. After ripening, the program is cooled, and high-speed centrifugation, 0.45 mu m membrane filtration are carried out. Finally, spray drying (air inlet 150-200 DEG C) or freeze drying (-20 DEG C to 0 DEG C sublimation) is adopted, and airflow crushing is carried out to screen out 1-2 mm particles.

[0057] Preparation method of inorganic flocculant B: The agent is in the form of grayish white particles and is prepared by using magnetic field assisted-dynamic rheological regulation technology, and the specific steps are as follows: (1) Silicon source activation: take sodium silicate with a modulus of 3.0-3.8, prepare an 8-18% SiO2 solution, add 0.05-0.2% silane coupling agent, and carry out ultrasonic dissolution and ultraviolet ozone pretreatment. Two-stage dissolution (room temperature / high temperature) is adopted and mixed to ensure complete activation of the monomer.

[0058] (2) Magnetic field directional acidification: in a spiral magnetic field environment with a magnetic induction intensity of 0.3-0.8 T, a composite acidifying agent (hydrochloric acid + buffer or CO2 microbubbles) is added dropwise to the sodium silicate solution. Four-stage pH control (11.0→9.5→8.5→7.8→7.2) is performed, and the viscosity (controlled at 15-50 mPa·s) is monitored in real time by an online rheometer to prevent gelation.

[0059] (3) Microwave ultrasonic synergistic polymerization and crosslinking: start microwave (600-1000 W pulse) and ultrasonic (300-600 W), and program the temperature to 75 DEG C. Batch add crosslinking enhancers: add aluminum salt (PAC) in the early stage, add borate in the middle stage, and add rare earth modifier (lanthanum / cerium nitrate) in the later stage to construct a multi-element crosslinking network.

[0060] (4) Dynamic aging and post-treatment: adopt a variable-temperature aging program (50 DEG C→30 DEG C→15 DEG C), and carry out periodic high-shear dispersion during the period. After aging, the pH is adjusted to 6.8-7.5. The solution is concentrated by nanofiltration membrane (1000-5000 Da cut-off) and desalted by reverse osmosis. Finally, freeze drying or low-temperature spray drying is adopted, and chitosan / nano-SiO2 microcapsule coating is carried out, and airflow classification is carried out to obtain particle products.

[0061] The flocculator tank 2 of the present application is used for livestock manure treatment in cooperation with the flocculant prepared above. Control stage one (coagulation): after water is fed, the controller instructs the dosing box 4 to add inorganic flocculant A. Due to the directional three-dimensional structure constructed by ultrasonic microwave synergy of the flocculant, under the medium-speed stirring of the motor 3, the manure colloid charge is quickly neutralized to form micro-flocs.

[0062] Control stage two (compaction): the controller instructs the addition of inorganic flocculant B. Since the flocculant is a super-high polymerization degree chain molecule that grows under the guidance of the magnetic field, and contains aluminum / boron / rare earth multi-crosslinking points, under the low-speed stirring of motor 3, it strongly nets and adsorbs the micro-flocs to form large and dense alum flowers.

[0063] Effect data: the supernatant discharged through the water decanter 7 has a COD removal rate increased by more than 20% compared with the use of ordinary commercial reagents, the water content of the precipitate is reduced by 15%, and due to the anti-gelation property of the flocculant, there is no blockage phenomenon in the sludge discharge process.

[0064] Working principle: first, the livestock manure is pretreated for solid-liquid separation, and after removing coarse impurities, the treated manure liquid is obtained, the liquid is conveyed to the flocculation sedimentation tank body 2 installed on the flocculation sedimentation tank outer support 10 through the water inlet pipeline 1, the feeding height is controlled at three quarters of the tank body to prevent liquid overflow during subsequent stirring. At this time, the controller 16 integrated in the flocculant addition control box 4 starts the preset program, first enters the coagulation step: the controller 16 instructs the flocculant addition control box 4 to add 13% PAC solution to the tank through the flocculant addition pipeline 5 at a rate of 1.3 kg / m3 of manure, and simultaneously starts the variable frequency stirring motor 3, the output end of which is connected to the stirring impeller 6 driven by the rotating rod 13 at a speed not greater than 600 r / min for the first stage stirring, and the aluminum ions released by PAC quickly neutralize the negative charge of colloidal particles in the manure to make the colloidal particles unstable and form micro-flocs.

[0065] After the coagulation step lasts for 3 minutes, the device automatically enters the flocculation growth step: the controller 16 adjusts the flocculant addition control box 4 to add 13% inorganic flocculant A at a rate of 2.6 kg / m3 of manure, and simultaneously increases the rotating speed of the variable frequency stirring motor 3 to not greater than 1000 r / min for the second stage stirring. The strong acid modified vermiculite connects the micro-flocs by adsorption and bridging due to its porous structure and charge characteristics, which promotes the increase of the volume of the flocs. In this process, the heating structure 15 on the flocculation sedimentation tank outer support 10 outside the tank body works synchronously, and the temperature sensor 1504 monitors the temperature of the manure in the tank in real time. If the temperature is lower than 15℃, multiple heating elements 1501 are triggered to start, and the heat is transferred to the heat conduction ring 1503 outside the tank body through the heat conduction rod 1502, and then uniformly conducted to the tank, so as to maintain the temperature of the manure at 20-25℃, which ensures the adsorption activity of the flocculant A and avoids slow growth of the flocs caused by low temperature.

[0066] After the flocculation growth step lasts for 3 minutes, the compaction step is entered: the controller 16 continues to instruct the flocculant dosing control box 4 to add 13% inorganic flocculant B at an amount of 2.6 kg / m3 of manure, and the variable frequency stirring motor 3 keeps the rotating speed not more than 1000 r / min for the third stage stirring. The strong alkali modified montmorillonite has strong net trapping ability, can quickly wrap the increased flocculation, fill the gap between the flocculation and enhance the structural stability, and finally form a dense and easy to settle large size flocculation. After stirring for 5 minutes, the variable frequency stirring motor 3 stops working, and the device enters the 10-minute standing and settling stage.

[0067] After the standing is finished, the separation step is started: the controller 16 controls the water decanter electric control telescopic pipe 8 to drive the water decanter 7 to descend at a speed not more than 10 cm / min, and the turbidity probe on the water decanter 7 detects the liquid turbidity in real time. When the probe contacts the precipitate layer, the telescopic pipe immediately stops descending, the supernatant is introduced into the supernatant outlet pipe 9 through the water decanter 7 and discharged into the subsequent treatment system; 5 minutes after the decanting is finished, the controller 16 opens the valve 17 outside the precipitate outlet 11, at this time the anti-blocking structure 14 at the bottom end of the tank body plays a role, the multiple cleaning brushes 1402 at the bottom end of the rotating rod 13 slowly rotate with the rotating rod 13, and the precipitate accumulated on the surface of the filter plate 1401 is cleaned, at the same time, the upwardly inclined turnover plate 1403 on one side of the cleaning brush 1402 scatters the caked precipitate, avoids the precipitate from blocking the filter plate 1401 and the outlet, and ensures that the precipitate is smoothly discharged. The discharged precipitate can be directly added with rice chaff, fungus chaff and other auxiliary materials for composting, or further treated after being pressed by a plate and frame filter. When the precipitate is completely discharged, the water inlet pipe 1 is started again to start the treatment process of the next batch of manure. The whole process realizes full-automatic intelligent control without frequent manual intervention, guarantees the flocculation efficiency, widens the utilization way of the manure treatment residues through the non-toxic reagent and resource recycling design, and reduces the comprehensive operation cost.

Claims

1. A method for segmenting livestock manure flocculation, characterized in that, The method comprises the following steps: S1, a pretreatment step: solid-liquid separation is performed on livestock and poultry manure to obtain a manure original solution to be treated, and the manure original solution is sent into a flocculation sedimentation tank through a water inlet pipeline (1); S2, a coagulation step: a polyaluminum chloride is added into the manure original solution through a flocculant adding control box (4) via a flocculant adding pipeline (5), and a variable frequency stirring motor (3) is started, and a rotating rod (13) connected to an output end of the variable frequency stirring motor (3) drives a stirring impeller (6) to perform first-stage stirring, so that colloidal particles in the manure are destabilized to form tiny flocculation cores; S3, a flocculation growth step: subsequently, an inorganic flocculant A serving as a flocculation core is added through the flocculant adding control box (4), and the stirring impeller (6) is driven by the variable frequency stirring motor (3) to perform second-stage stirring, so that the tiny flocculation cores are gradually increased through adsorption and bridging; S4, a compaction step: then, an inorganic flocculant B for enhancing flocculation compactness is added through the flocculant adding control box (4), and the stirring impeller (6) is driven by the variable frequency stirring motor (3) to perform third-stage stirring, so that large-size flocculation bodies which are compact and easy to settle are formed; The inorganic flocculant A is strong-acid-modified vermiculite, and the inorganic flocculant B is strong-alkali-modified montmorillonite.

2. The method according to claim 1, wherein, After the S4 step, the method further comprises a separation step of stopping the stirring of the variable frequency stirring motor (3), allowing the large-size flocculation bodies to settle, and separating supernatant and sediment through a water decanter (7) connected to a supernatant outlet pipeline (9) and a valve (17) arranged on a sediment outlet (11). The variable frequency stirring motor (3) is controlled by a controller (16) integrated in the flocculant adding control box (4), so that the stirring speed of the first-stage stirring is not greater than 600 r / min, the stirring speed of the second-stage stirring is not greater than 1000 r / min and is higher than the stirring speed of the first-stage stirring; 3. The method according to claim 1, wherein the method is characterized by, The stirring speed of the third-stage stirring is the same as the stirring speed of the second-stage stirring. The strong-acid-modified vermiculite is prepared by using a sulfuric acid solution with a concentration of 1-4 mol / L to modify vermiculite at 80-100 ℃ for 2-4 hours.

4. The method according to claim 1, wherein, The strong-alkali-modified montmorillonite is prepared by using a sodium hydroxide solution with a concentration of 0.5-2 mol / L to modify montmorillonite at 60-90 ℃ for 1-3 hours.

5. The method according to claim 1, wherein the method is characterized by, ​ 6. A livestock manure sectional flocculation device, using a livestock manure sectional flocculation method according to any one of claims 1 to 5, characterized in that, Including the flocculation precipitator jar (2), the flocculation precipitator jar (2) is provided with the water inlet pipeline (1) on the outside one side, the water inlet pipeline (1) is provided with the feeding hopper (12) on the other end, the water inlet pipeline (1) one end is connected with the flocculation precipitator jar (2) inside, the flocculation precipitator jar (2) upper portion is fixedly installed with the variable frequency stirring motor (3), the variable frequency stirring motor (3) output is fixedly connected with the rotating rod (13), the rotating rod (13) outside is provided with a plurality of stirring impellers (6), the flocculation precipitator jar (2) upper portion one side is also fixedly installed with the flocculating agent dosing control box (4), the flocculating agent dosing control box (4) one side is fixedly connected with the flocculating agent dosing pipeline (5), the flocculating agent dosing pipeline (5) is connected with the flocculation precipitator jar (2) inside, the flocculation precipitator jar (2) outside is provided with the flocculation precipitator outer support (10); The flocculation precipitator jar (2) is provided with the anti-blocking structure (14) on the inside bottom, which is used for placing the treated material to accumulate on the bottom, and the heating structure (15) is further fixedly installed on the upper portion of the flocculation precipitator outer support (10), which is used for heating the inside of the flocculation precipitator jar (2), so that the material is fused.

7. The livestock and poultry manure segmented flocculation device according to claim 6, characterized in that, The flocculation precipitator jar (2) is further provided with the supernatant outlet pipe (9) for discharging supernatant, the flocculation precipitator jar (2) bottom is provided with the sediment outlet (11) for discharging sediment, the sediment outlet (11) is provided with a valve (17) on the outside, one end of the supernatant outlet pipe (9) is connected with the decanter (7), the decanter (7) is used for skimming the supernatant from the supernatant surface, and the decanter (7) is lifted by the decanter electric control telescopic pipe (8).

8. The livestock manure sectional flocculation device according to claim 6, characterized in that, The anti-blocking structure (14) includes a filter plate (1401) fixedly installed on the inside bottom of the flocculation precipitator jar (2), a plurality of cleaning brushes (1402) are fixedly installed on the bottom of the rotating rod (13), and the plurality of cleaning brushes (1402) are arranged above the filter plate (1401). A plurality of the cleaning brushes (1402) are inclined and installed with a turnover plate (1403) on one side.

9. The livestock and poultry manure sectional flocculation device according to claim 6, characterized in that, The heating structure (15) includes a plurality of heating elements (1501) fixedly installed on the upper portion of the flocculation precipitator outer support (10), a plurality of heat conducting rods (1502) are arranged on the upper portion of the plurality of heating elements (1501), a heat conducting ring (1503) is arranged on the outside of the flocculation precipitator jar (2), and the plurality of heat conducting rods (1502) are connected with the heat conducting ring (1503). The flocculation precipitator jar (2) is provided with a temperature sensor (1504).

10. The livestock manure sectional flocculation device according to claim 6, characterized in that, The controller (16) is integrated in the flocculating agent dosing control box (4), and the controller (16) is pre-provided with dosing programs and stirring programs corresponding to the coagulation step, the flocculation growth step and the densification step.

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