Landfill leachate pretreatment device

Abstract

The invention belongs to the technical field of sewage and wastewater treatment, and particularly relates to a landfill leachate pretreatment device which comprises a grid filter box, a pH adjusting box, a demulsification pool and an air floatation pool, a first stirring assembly is fixedly installed at the bottom of the inner wall of the pH adjusting box, a second stirring assembly is fixedly installed at the bottom of the inner wall of the demulsification pool, and a first stirring assembly is fixedly installed at the bottom of the inner wall of the first stirring assembly; an aeration pipe network is fixedly arranged at the bottom of the inner wall of the air floatation tank, a slag scraper is fixedly arranged at the upper end of the air floatation tank, and the device further comprises a sample filter pressing treatment mechanism, a sampling mechanism, a diluting mechanism, a demulsifying agent adding mechanism, a demulsifying agent adding amount regulating and controlling mechanism and a plurality of groups of air floatation bubble size regulating and controlling mechanisms. The device can be used for performing multi-stage treatment on the kitchen waste, efficiently removing oil and quickly measuring the oil content and electrokinetic potential of the leachate to judge the emulsification degree, so that the addition amount of the demulsifier is automatically regulated and controlled, the bubble size of the air floatation tank is automatically regulated according to the oil content, and the treatment efficiency and quality are improved.

Description

Technical Field

[0001] The invention belongs to the technical field of sewage and wastewater treatment, and in particular relates to a landfill leachate pretreatment device. Background Art

[0002] The landfill leachate pretreatment device is an equipment system that performs preliminary purification on high-concentration organic wastewater (leachate) generated during the stacking, transportation or treatment of garbage. Its core function is to remove large particle impurities, suspended matter, some organic matter, grease and other pollutants in the leachate through physical, chemical or physicochemical methods, creating favorable conditions for subsequent deep treatment (such as biochemical treatment, membrane treatment, etc.). For example, the patent with patent announcement number CN110143699A proposes a landfill leachate pretreatment device for a garbage compression station.

[0003] Kitchen waste is mainly composed of food residues, grease and soup. One of its notable characteristics is that the grease content is much higher than other types of garbage. Since grease has the physical properties of low-temperature condensation and strong adhesion, if it enters the treatment system directly without pretreatment, it is easy to condense and adhere to the pipe wall in a low-temperature environment, causing pipe blockage. At the same time, it will adhere to the surfaces of various components of the sewage and wastewater treatment equipment, hindering material transfer and reducing equipment operation efficiency. In addition, the grease in the leachate of kitchen waste mostly exists in an emulsified state - surfactants, proteins, fatty acids and other substances in food will form a stable emulsion layer at the oil-water interface, tightly wrapping the oil droplets, making it difficult to achieve effective separation through conventional gravity sedimentation or flotation processes, greatly affecting the treatment efficiency and separation effect of grease. Summary of the Invention

[0004] The purpose of the present invention is to provide a landfill leachate pretreatment device in view of the above problems.

[0005] To achieve the above-mentioned object, the present invention adopts the following technical solutions: a landfill leachate pretreatment device, comprising a grid filter box, a pH adjustment box, an emulsion breaking tank, and an air flotation tank, wherein the grid filter box, the pH adjustment box, the emulsion breaking tank, and the air flotation tank are connected and arranged, a first stirring assembly is fixedly installed on the bottom of the inner wall of the pH adjustment box, a second stirring assembly is fixedly installed on the bottom of the inner wall of the emulsion breaking tank, an aeration pipe network is fixedly installed on the bottom of the inner wall of the air flotation tank, a scraper is fixedly installed on the upper end of the air flotation tank, and a laser Doppler electrophoresis instrument is fixedly installed on the upper end of the pH adjustment box, and further comprising: The sample filter press processing mechanism is fixedly installed at the upper end of the pH adjustment box and is arranged corresponding to the laser Doppler electrophoresis instrument; The sampling mechanism is fixedly installed between the pH adjustment box and the sample filter press processing mechanism; a dilution mechanism, fixedly mounted inside the sample filter press processing mechanism; A demulsifier adding mechanism is fixedly installed at the upper end of the demulsification tank; a demulsifier addition amount control mechanism, fixedly mounted on the outer wall of the sample filter press processing mechanism, for controlling the operation of the demulsifier addition mechanism; A plurality of groups of flotation bubble size regulating mechanisms are fixedly connected to the air outlet at the upper end of the aeration pipe network.

[0006] In the above-mentioned landfill leachate pretreatment device, the sample filter press treatment mechanism includes a protective cover fixedly mounted on the upper end of the pH adjusting box, the inner wall of the protective cover is fixedly connected to a filter press cartridge through a support frame, the lower end of the filter press cartridge is fixedly connected to a water outlet pipe, a filter screen is fixedly mounted on the bottom of the inner wall of the filter press cartridge, a filter membrane is attached to the upper side of the filter screen, an electric slide rail is fixedly mounted on the top of the inner wall of the protective cover, a movable frame is fixedly connected to the lower end of the slider in the electric slide rail, an electric push rod is fixedly inserted on the movable frame, the lower end of the electric push rod is fixedly connected to a pressurizing piston corresponding to the filter press cartridge, and an infrared oil measuring instrument is also fixedly mounted on the support frame.

[0007] In the above-mentioned landfill leachate pretreatment device, the sampling mechanism includes a threaded lifting assembly fixedly mounted on the upper end of the pH adjusting box, the movable end of the threaded lifting assembly is fixedly connected to a lifting rod, the lower end of the lifting rod passes through the pH adjusting box and is fixedly connected to an extension plate, a sampling head is fixedly inserted on the extension plate, and a filling head is also fixedly inserted at the lower end of the movable frame, an elastic telescopic tube is fixedly connected between the sampling head and the filling head, a sampling pump is mounted on the elastic telescopic tube, and the sampling pump is fixedly mounted on the outer wall of the protective cover.

[0008] In the above-mentioned landfill leachate pretreatment device, the dilution mechanism includes a dilution pipe fixedly mounted on the support frame, a dilution pump is mounted on the dilution pipe, the dilution pump is also fixedly mounted on the support frame, and a flow meter is also mounted on the dilution pipe.

[0009] In the above-mentioned landfill leachate pretreatment device, the demulsifier adding mechanism includes two electric guide rails symmetrically fixedly installed on the outer wall of the upper end of the demulsification tank, one end of the slider in the two electric guide rails is fixedly connected to the same U-shaped reciprocating plate, and a plurality of dosing heads are evenly fixedly inserted on the U-shaped reciprocating plate. The upper ends of the plurality of dosing heads are fixedly connected to the same buffer tube, and one end of the buffer tube is fixedly connected to a drug supply tube, and a drug supply pump is installed on the drug supply tube, and the drug supply pump is fixedly installed on the upper end of the U-shaped reciprocating plate.

[0010] In the above-mentioned landfill leachate pretreatment device, the demulsifier addition amount control mechanism includes a control shell fixedly mounted on the outer wall of the protective cover, the inner wall of the control shell is rotatably connected to an adjusting screw, the outer wall of the control shell is fixedly mounted with an adjusting motor for driving the adjusting screw to rotate, the rod wall of the adjusting screw is threadedly sleeved with an adjusting seat, one end of the adjusting seat is fixedly connected to a rotary potentiometer, the outer wall of the adjusting seat is also fixedly connected to a reduction gear box through an L-shaped connecting frame, the output end of the reduction gear box is fixedly connected to the center point of the rotating end of the rotary potentiometer, the input end of the reduction gear box is fixedly connected to a transmission gear, and the inner wall of the control shell is fixedly mounted with a transmission rack meshing with the transmission gear.

[0011] In the above-mentioned landfill leachate pretreatment device, the flotation bubble size control mechanism includes an aeration head fixedly connected to the air outlet of the aeration pipe network, a plurality of arc-shaped aeration holes are evenly opened on the upper end of the aeration head, a micro motor is fixedly installed on the top of the inner wall of the aeration head, the output end of the micro motor passes through the upper end of the aeration head and is fixedly connected to a rotating block, the outer wall of the rotating block is evenly and fixedly connected to a plurality of blocking strips arranged corresponding to the positions of the arc-shaped aeration holes, and a rotation angle sensor is also installed at the output end of the micro motor.

[0012] In the above-mentioned landfill leachate pretreatment device, the outer wall of the adjustment seat is fixedly connected to the limit slider, and the inner wall of the control shell is provided with a limit sliding groove that matches and slides with the limit slider.

[0013] Compared with the existing technology, the beneficial effects of the present invention are: 1. Through the set grid filter box, pH adjustment box, emulsion breaking tank and flotation tank, the restaurant kitchen waste can be treated in multiple stages, and the grease in the restaurant kitchen waste can be treated more effectively, with stronger targeting and higher grease removal quality.

[0014] 2. Through the set sample filter press processing mechanism, sampling mechanism, dilution mechanism, and laser Doppler electrophoresis instrument, the oil content and zeta potential of the food waste leachate can be quickly measured, the emulsification degree of the food waste leachate can be judged, and then an accurate judgment basis for the subsequent addition amount of demulsifier can be provided.

[0015] 3. Through the set demulsifier adding mechanism and demulsifier adding amount control mechanism, the demulsifier adding amount can be automatically controlled based on the oil content and emulsification degree of the food waste leachate, making the demulsifier adding amount more accurate, avoiding the problem that too much or too little demulsifier adding will affect the quality and efficiency of oil treatment.

[0016] 4. Through the flotation tank, aeration pipe network and flotation bubble size control mechanism, the size of the bubbles in the flotation tank can be automatically controlled based on the oil content of the food waste leachate, so that small bubbles are used when the oil content is high and large bubbles are used when the oil content is low. Under the premise of ensuring stable adhesion of oil droplets, the flotation efficiency is improved as much as possible. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the three-dimensional structure of the present invention; Figure 2 It is a schematic diagram of the front cross-sectional structure of the present invention; Figure 3 yes Figure 2 The middle part is an enlarged structural diagram; Figure 4 It is a schematic cross-sectional view of the sample filter press processing mechanism of the present invention; Figure 5 It is a structural schematic diagram of the sampling mechanism of the present invention; Figure 6 It is a structural schematic diagram of the dilution mechanism of the present invention; Figure 7 It is a structural schematic diagram of the demulsifier adding mechanism of the present invention; Figure 8 It is a schematic cross-sectional view of the demulsifier addition amount control mechanism of the present invention; Figure 9 It is a schematic cross-sectional view of the air flotation bubble size control mechanism of the present invention.

[0018] In the figure: 1 grid filter box, 2 sample filter processing mechanism, 21 protective cover, 22 support frame, 23 filter cartridge, 24 water outlet pipe, 25 filter screen, 26 filter membrane, 27 electric slide rail, 28 moving frame, 29 electric push rod, 210 pressurizing piston, 211 infrared oil measuring instrument, 3 sampling mechanism, 31 threaded lifting assembly, 32 lifting rod, 33 extension plate, 34 sampling head, 35 filling head, 36 elastic telescopic tube, 37 sampling pump, 4 dilution mechanism, 41 dilution tube, 42 dilution pump, 43 flow meter, 5 demulsifier adding mechanism, 51 electric guide rail, 52 U-shaped reciprocating plate, 53 dosing head, 54 Buffer tube, 55 drug supply tube, 56 drug supply pump, 6 demulsifier addition amount control mechanism, 61 control shell, 62 adjustment screw, 63 adjustment motor, 64 adjustment seat, 65 rotary potentiometer, 66 reduction gear box, 67 transmission gear, 68 transmission rack, 7 flotation bubble size control mechanism, 71 aeration head, 72 arc aeration hole, 73 micro motor, 74 rotating block, 75 blocking strip, 76 rotation angle sensor, 8 pH adjustment box, 9 demulsification tank, 10 flotation tank, 11 first stirring assembly, 12 second stirring assembly, 13 aeration pipe network, 14 scraper, 15 laser Doppler electrophoresis instrument. DETAILED DESCRIPTION

[0019] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0020] like Figures 1-9 As shown, a landfill leachate pretreatment device includes a grid filter box 1, a pH adjustment box 8, an emulsion breaking tank 9, and an air flotation tank 10, wherein the grid filter box 1, the pH adjustment box 8, the emulsion breaking tank 9, and the air flotation tank 10 are connected. A first stirring assembly 11 is fixedly installed at the bottom of the inner wall of the pH adjustment box 8, a second stirring assembly 12 is fixedly installed at the bottom of the inner wall of the emulsion breaking tank 9, an aeration pipe network 13 is fixedly installed at the bottom of the inner wall of the air flotation tank 10, a scraper 14 is also fixedly installed at the upper end of the air flotation tank 10, and a laser Doppler electrophoresis instrument 15 is fixedly installed at the upper end of the pH adjustment box 8. The device also includes: The sample filter press processing mechanism 2 is fixedly mounted on the upper end of the pH adjusting box 8 and is arranged corresponding to the laser Doppler electrophoresis instrument 15. The sample filter press processing mechanism 2 includes a protective cover 21 fixedly mounted on the upper end of the pH adjusting box 8. The inner wall of the protective cover 21 is fixedly connected to a filter press cartridge 23 through a support frame 22. The lower end of the filter press cartridge 23 is fixedly connected to a water outlet pipe 24. A filter screen 25 is fixedly mounted on the bottom of the inner wall of the filter press cartridge 23. A filter membrane 26 is attached to the upper side of the filter screen 25. An electric slide rail 27 is fixedly mounted on the top of the inner wall of the protective cover 21. The lower end of the slider in the electric slide rail 27 is fixedly connected to a moving frame 28. An electric push rod 29 is fixedly inserted on the moving frame 28. The lower end of the electric push rod 29 is fixedly connected to a pressurizing piston 210 corresponding to the filter press cartridge 23. An infrared oil measuring instrument 211 is also fixedly mounted on the support frame 22.

[0021] The sampling mechanism 3 is fixedly installed between the pH adjusting box 8 and the sample filter press processing mechanism 2. The sampling mechanism 3 includes a threaded lifting assembly 31 fixedly installed on the upper end of the pH adjusting box 8. The movable end of the threaded lifting assembly 31 is fixedly connected to a lifting rod 32. The lower end of the lifting rod 32 passes through the pH adjusting box 8 and is fixedly connected to an extension plate 33. A sampling head 34 is fixedly inserted on the extension plate 33. A filling head 35 is also fixedly inserted at the lower end of the movable frame 28. An elastic telescopic tube 36 is fixedly connected between the sampling head 34 and the filling head 35. A sampling pump 37 is installed on the elastic telescopic tube 36. The sampling pump 37 is fixedly installed on the outer wall of the protective cover 21.

[0022] The dilution mechanism 4 is fixedly installed inside the sample filter press processing mechanism 2. The dilution mechanism 4 includes a dilution tube 41 fixedly installed on the support frame 22. A dilution pump 42 is installed on the dilution tube 41. The dilution pump 42 is also fixedly installed on the support frame 22. A flow meter 43 is also installed on the dilution tube 41.

[0023] The demulsifier adding mechanism 5 is fixedly installed at the upper end of the demulsification tank 9. The demulsifier adding mechanism 5 includes two electric guide rails 51 symmetrically fixedly installed on the outer wall of the upper end of the demulsification tank 9. One end of the slider in the two electric guide rails 51 is fixedly connected to the same U-shaped reciprocating plate 52. A plurality of dosing heads 53 are evenly fixedly inserted on the U-shaped reciprocating plate 52. The upper ends of the plurality of dosing heads 53 are fixedly connected to the same buffer tube 54. One end of the buffer tube 54 is fixedly connected to a drug supply tube 55. A drug supply pump 56 is installed on the drug supply tube 55. The drug supply pump 56 is fixedly installed on the upper end of the U-shaped reciprocating plate 52.

[0024] The demulsifier addition amount control mechanism 6 is fixedly mounted on the outer wall of the sample filter press processing mechanism 2 and is used to control the operation of the demulsifier addition mechanism 5. The demulsifier addition amount control mechanism 6 includes a control shell 61 fixedly mounted on the outer wall of the protective cover 21. The inner wall of the control shell 61 is rotatably connected to an adjusting screw 62. The outer wall of the control shell 61 is fixedly mounted with an adjusting motor 63 for driving the adjusting screw 62 to rotate. The rod wall of the adjusting screw 62 is threadedly sleeved with an adjusting seat 64. One end of the adjusting seat 64 is fixedly connected to a rotary potentiometer 65. The outer wall of the adjusting seat 64 is also fixedly connected to a reduction gear box 66 through an L-shaped connecting frame. The output end of the reduction gear box 66 is fixedly connected to the center point of the rotating end of the rotary potentiometer 65, and the input end of the reduction gear box 66 is fixedly connected to a transmission gear 67. The inner wall of the control shell 61 is fixedly mounted with a transmission rack 68 meshing with the transmission gear 67. The outer wall of the adjusting seat 64 is fixedly connected to a limit slider, and the inner wall of the control shell 61 is provided with a limit slide groove that matches the limit slider.

[0025] Multiple groups of flotation bubble size control mechanisms 7 are fixedly connected to the upper air outlet of the aeration pipe network 13. The flotation bubble size control mechanisms 7 include an aeration head 71 fixedly connected to the air outlet of the aeration pipe network 13. A plurality of arc-shaped aeration holes 72 are evenly provided on the upper end of the aeration head 71. A micro motor 73 is fixedly installed on the top of the inner wall of the aeration head 71. The output end of the micro motor 73 passes through the upper end of the aeration head 71 and is fixedly connected to a rotating block 74. The outer wall of the rotating block 74 is evenly and fixedly connected to a plurality of blocking strips 75 arranged corresponding to the positions of the arc-shaped aeration holes 72. A rotation angle sensor 76 is also installed at the output end of the micro motor 73.

[0026] The operating principle of the present invention is described as follows: the leachate of the kitchen waste is first sent into the grid filter box 1, which effectively filters and intercepts the food residues carried in the leachate of the kitchen waste, and can remove large particles of suspended matter, thereby reducing interference with the subsequent use of the demulsifier; The food waste leachate filtered through the grid then enters the pH adjustment box 8, where the pH value of the food waste leachate is adjusted to neutral. Since the activity of the demulsifier is significantly affected by pH, and the food waste leachate is typically acidic (pH 4-6), the pH must be adjusted to 7-9 before adding the demulsifier. The addition and detection of the pH agent are existing technologies of existing wastewater treatment institutions and will not be elaborated on here. During the pH adjustment process of the food waste leachate, the first stirring component 11 is used to drive the food waste leachate to mix, which not only improves the pH adjustment efficiency but also homogenizes the food waste leachate, facilitating subsequent detection and processing. After the pH of the food waste leachate is adjusted, the PLC controller fixed on the outer wall of the protective cover 21 controls the threaded lifting assembly 31 to drive the lifting rod 32 and the sampling head 34 to move downward, so that the sampling head 34 moves to the middle position of the food waste leachate. The PLC controller then controls the sampling pump 37 to work, and the sampling pump 37 transports the mixed food waste leachate to the filling head 35 through the elastic telescopic tube 36. When sampling, the PLC controller pre-controls the electric slide rail 27 The moving frame 28 is driven to move, so that the filling head 35 moves to the upper side of the filter press 23, so that the food waste leachate output by the filling head 35 will fall into the filter press 23. After the sampling work is completed, the PLC controller controls the threaded lifting component 31 to drive the sampling head 34 to reset to the initial position, and controls the electric slide rail 27 to drive the moving frame 28 to move again, so that the pressurizing piston 210 moves to the upper end of the filter press 23, and the PLC controller controls the electric push rod 29 to push the pressurizing piston 210 downward. The food waste leachate is injected into the filter press 23 and pressurized, so that the food waste leachate is simply filtered through the filter screen 25 and the filter membrane 26 to remove the solid particles in the food waste leachate. The filtered food waste leachate falls into the sample tank of the laser Doppler electrophoresis instrument 15 through the outlet pipe 24. The infrared oil meter 211 then detects the oil content of the food waste leachate sent to the sample tank and feeds back the detection result signal to the PLC controller. Based on the oil content, the PLC controller controls the dilution mechanism 4 to self-regulate. The dilution pump 42 cooperates with the dilution tube 41 to inject deionized water into the sample tank of the laser Doppler electrophoresis instrument 15 to mix with the sampled food waste leachate. The dilution factor depends on the oil content. The higher the oil content, the denser the oil droplets, and the higher the dilution factor. This dilution factor is between 10 and 100 times. The flow meter 43 can accurately determine the injection amount of deionized water, thereby accurately controlling the dilution factor. The laser Doppler electrophoresis instrument 15 measures the zeta potential through the process of "electric field drive-laser scattering-signal analysis". The zeta potential refers to the potential difference between the sliding surface and the bulk solution in the double electric layer on the surface of the colloidal particles, reflecting the charge properties and strength of the particle surface. In the emulsified system of food waste leachate, the surface of the oil droplets is charged due to the adsorption of ions in the water (such as fatty acid salts, surfactants, etc.), forming a double electric layer, which generates electrostatic repulsion between the oil droplets and maintains the stability of the emulsion. If the absolute value of the zeta potential on the surface of the oil droplets is high (such as the absolute value >30mV), it means that the charge The repulsive force is strong, the emulsion is highly stable, and demulsification is difficult. If the absolute value of the zeta potential decreases to near zero (±5mV) or the charge sign is reversed, the repulsive force between the oil droplets disappears, and they aggregate due to the van der Waals force, the emulsion stability decreases, and it is easy to demulsify. That is, the higher the zeta potential detection, the greater the emulsification of the oil droplets in the food waste leachate. The treatment and dilution of the solid particles in the food waste leachate described above can avoid the interference of solid particles on the zeta potential measurement of the oil droplets, and avoid the problem that the oil droplets in the food waste leachate are too dense and affect the potential measurement. The pH-adjusted food waste leachate is transported to the demulsifier tank 9 again. The PLC controller controls the electric guide rail 51 to drive the U-shaped reciprocating plate 52 to move. The drug supply pump 56 cooperates with the drug supply pipe 55 to transport the demulsifier into the buffer pipe 54. Then, the demulsifier is added to the demulsifier tank 9 through multiple dosing heads 53. The second stirring component 12 efficiently mixes the food waste leachate with the demulsifier. Because the oil in the food waste leachate is often in an emulsified state (due to the surfactants, proteins, fatty acids, etc. in the food waste water), the food waste leachate is not easily mixed. The substance forms a stable emulsion). At this time, the oil droplets are wrapped by the emulsifier and are difficult to separate directly by gravity or flotation. The role of the demulsifier is to destroy the stable structure of the emulsion, so that the oil droplets are out of the emulsified state and aggregate into larger oil particles, creating conditions for subsequent flotation separation. The demulsifier destroys the stability of the emulsified oil droplets by charge neutralization, adsorption bridging or destruction of the hydrophilic groups of the emulsifier. The demulsifier first reacts with the emulsified oil to destroy its interfacial film, and the oil droplets collide and merge with each other to form larger oil particles (from micron to millimeter); The PLC controller controls the action of the demulsifier addition control mechanism 6 based on the oil content and emulsification degree in the food waste leachate fed back by the infrared oil measuring instrument 211 and the laser Doppler electrophoresis instrument 15. The greater the oil content in the food waste leachate and the higher the electromotive force of the oil droplets detected, the longer the adjustment motor 63 will work. The adjustment motor 63 drives the adjustment screw 62 to rotate. The threaded connection between the adjustment screw 62 and the adjustment seat 64 drives the rotary potentiometer 65 to move, thereby causing the transmission gear 67 to engage with the transmission rack 68, and cooperate with the reduction gear box 66 to drive the rotating end of the rotary potentiometer 65 to rotate, thereby causing the access resistance of the rotary potentiometer 65 to gradually decrease, and the rotary potentiometer 65 is connected in series to the power supply circuit of the drug supply pump 56. On the way, the drug supply pump 56 is a DC pump, which makes the drug supply pump 56 more powerful, so that more demulsifiers can be added within the fixed working time of the demulsifier adding mechanism 5, because the greater the oil content of the food waste leachate, the more oil droplets need to be demulsified, and the higher the electromotive force detected by the oil droplets, the greater the emulsification degree of the oil droplets, the more difficult it is to demulsify, and more demulsifiers are needed to complete the demulsification work, and then the addition amount of the demulsifier is automatically regulated to avoid insufficient addition of demulsifier, which will cause the oil droplets to not fully coalesce, and a large number of fine oil droplets will still remain during flotation, resulting in excessive oil content in the effluent. If the demulsifier is added in an excessive amount, the demulsifier itself will form colloids or flocs, which will wrap the oil particles, or react with organic matter in the water to produce a large amount of sticky sludge, resulting in the problem of too thick a scum layer in the flotation tank 10 and difficulty in scraping the scum; After the demulsifier is added, the food waste leachate is again transported to the flotation tank 10. The aeration pipe network 13 cooperates with the aeration head 71 and the arc-shaped aeration holes 72 to generate tiny bubbles. The tiny bubbles (diameter 50-100 μm) come into contact with the demulsified oil droplets. Due to the strong hydrophobicity of the oil particle surface, the bubbles adhere to the surface of the oil droplets, forming an "oil-bubble" complex. The overall density of the complex is less than that of water, so it quickly floats to the liquid surface, forming a scum layer. The scum layer is regularly removed by the scraper 14 to clean the grease in the food waste. Based on the infrared oil meter 211 detecting the oil content in the food waste leachate, the PLC controller automatically adjusts the working speed of the scraper 14. The higher the oil content, the slower the movement speed and the deeper the scum removal depth, ensuring stable scum removal. The PLC controller also controls the operation of the flotation bubble size control mechanism 7 based on the oil content in the food waste leachate. When the oil content is higher, the PLC controller controls the micromotor 73 to drive the deflection angle of the rotating block 74 to be smaller. The rotation angle sensor 76 can accurately obtain the rotation angle of the micromotor 73, thereby reducing the movement distance of the blocking strip 75, thereby increasing the degree of obstruction of the arc-shaped aeration hole 72 by the blocking strip 75, and making the usable aperture of the arc-shaped aeration hole 72 smaller, thereby making the generated bubbles smaller. When the oil content is high, the number of oil droplets is large, and more small bubbles are required to increase the probability of bubble-oil droplet collisions per unit volume to avoid insufficient oil droplet adhesion due to insufficient bubbles. When the oil content is low, the PLC controller controls the micromotor 73 to rotate at a larger angle, resulting in a larger usable aperture of the arc-shaped aeration hole 72, resulting in larger bubbles. When the oil content is low, the dispersion of oil droplets is low, and large bubbles can meet the adhesion requirements. Large bubbles also rise quickly, which can improve flotation efficiency.

[0027] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A landfill leachate pretreatment device, comprising a grid filter box (1), a pH adjustment box (8), a demulsification tank (9) and a flotation tank (10), wherein the grid filter box (1), the pH adjustment box (8), the demulsification tank (9) and the flotation tank (10) are connected and arranged, a first stirring assembly (11) is fixedly installed on the bottom of the inner wall of the pH adjustment box (8), a second stirring assembly (12) is fixedly installed on the bottom of the inner wall of the demulsification tank (9), an aeration pipe network (13) is fixedly installed on the bottom of the inner wall of the flotation tank (10), a scraper (14) is fixedly installed on the upper end of the flotation tank (10), and a laser Doppler electrophoresis instrument (15) is fixedly installed on the upper end of the pH adjustment box (8), characterized in that: Also includes: The sample filter press processing mechanism (2) is fixedly mounted on the upper end of the pH regulating box (8) and is arranged corresponding to the laser Doppler electrophoresis instrument (15); A sampling mechanism (3) is fixedly installed between the pH adjustment box (8) and the sample filter press processing mechanism (2); A dilution mechanism (4) is fixedly mounted inside the sample filter press processing mechanism (2); A demulsifier adding mechanism (5) is fixedly mounted on the upper end of the demulsification tank (9); A demulsifier addition amount control mechanism (6) is fixedly mounted on the outer wall of the sample filter press processing mechanism (2) and is used to control the operation of the demulsifier addition mechanism (5); Multiple groups of flotation bubble size control mechanisms (7) are fixedly connected to the upper air outlet of the aeration pipe network (13).

2. The landfill leachate pretreatment device according to claim 1, characterized in that: The sample filter press processing mechanism (2) includes a protective cover (21) fixedly mounted on the upper end of the pH regulating box (8), the inner wall of the protective cover (21) is fixedly connected to a filter cartridge (23) through a support frame (22), the lower end of the filter cartridge (23) is fixedly connected to a water outlet pipe (24), a filter screen (25) is fixedly mounted on the bottom of the inner wall of the filter cartridge (23), a filter membrane (26) is attached to the upper side of the filter screen (25), an electric slide rail (27) is fixedly mounted on the top of the inner wall of the protective cover (21), the lower end of the slider in the electric slide rail (27) is fixedly connected to a moving frame (28), an electric push rod (29) is fixedly inserted on the moving frame (28), the lower end of the electric push rod (29) is fixedly connected to a pressurizing piston (210) corresponding to the filter cartridge (23), and an infrared oil measuring instrument (211) is also fixedly mounted on the support frame (22).

3. The landfill leachate pretreatment device according to claim 2, characterized in that: The sampling mechanism (3) comprises a threaded lifting assembly (31) fixedly mounted on the upper end of the pH regulating box (8); the movable end of the threaded lifting assembly (31) is fixedly connected to a lifting rod (32); the lower end of the lifting rod (32) passes through the pH regulating box (8) and is fixedly connected to an extension plate (33); a sampling head (34) is fixedly inserted on the extension plate (33); a filling head (35) is also fixedly inserted on the lower end of the movable frame (28); an elastic telescopic tube (36) is fixedly connected between the sampling head (34) and the filling head (35); a sampling pump (37) is mounted on the elastic telescopic tube (36); and the sampling pump (37) is fixedly mounted on the outer wall of the protective cover (21).

4. The landfill leachate pretreatment device according to claim 2, characterized in that: The dilution mechanism (4) comprises a dilution tube (41) fixedly mounted on the support frame (22), a dilution pump (42) mounted on the dilution tube (41), the dilution pump (42) also fixedly mounted on the support frame (22), and a flow meter (43) mounted on the dilution tube (41).

5. The landfill leachate pretreatment device according to claim 1, characterized in that: The demulsifier adding mechanism (5) comprises two electric guide rails (51) symmetrically fixedly mounted on the outer wall of the upper end of the demulsification tank (9), one end of the slider in the two electric guide rails (51) is fixedly connected to the same U-shaped reciprocating plate (52), a plurality of dosing heads (53) are evenly fixedly inserted on the U-shaped reciprocating plate (52), the upper ends of the plurality of dosing heads (53) are fixedly connected to the same buffer tube (54), one end of the buffer tube (54) is fixedly connected to a drug supply tube (55), a drug supply pump (56) is mounted on the drug supply tube (55), and the drug supply pump (56) is fixedly mounted on the upper end of the U-shaped reciprocating plate (52).

6. The landfill leachate pretreatment device according to claim 2, characterized in that: The demulsifier addition amount control mechanism (6) comprises a control shell (61) fixedly mounted on the outer wall of the protective cover (21); an adjusting screw (62) is rotatably connected to the inner wall of the control shell (61); an adjusting motor (63) for driving the adjusting screw (62) to rotate is fixedly mounted on the outer wall of the control shell (61); an adjusting seat (64) is threadedly sleeved on the rod wall of the adjusting screw (62); one end of the adjusting seat (64) is fixedly connected to a rotary potentiometer (65); the outer wall of the adjusting seat (64) is also fixedly connected to a reduction gear box (66) via an L-shaped connecting frame; the output end of the reduction gear box (66) is fixedly connected to the center point of the rotating end of the rotary potentiometer (65); the input end of the reduction gear box (66) is fixedly connected to a transmission gear (67); and a transmission rack (68) meshing with the transmission gear (67) is fixedly mounted on the inner wall of the control shell (61).

7. The landfill leachate pretreatment device according to claim 1, characterized in that: The flotation bubble size control mechanism (7) comprises an aeration head (71) fixedly connected to the air outlet of the aeration pipe network (13), a plurality of arc-shaped aeration holes (72) are evenly opened on the upper end of the aeration head (71), a micro motor (73) is fixedly installed on the top of the inner wall of the aeration head (71), the output end of the micro motor (73) passes through the upper end of the aeration head (71) and is fixedly connected to a rotating block (74), the outer wall of the rotating block (74) is evenly fixedly connected to a plurality of blocking strips (75) arranged corresponding to the positions of the arc-shaped aeration holes (72), and a rotation angle sensor (76) is also installed at the output end of the micro motor (73).

8. The landfill leachate pretreatment device according to claim 6, characterized in that: The outer wall of the adjustment seat (64) is fixedly connected to a limit slider, and the inner wall of the control shell (61) is provided with a limit sliding groove that matches and slides with the limit slider.

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