Layered purification, recycling and reusing device for water-based chemical production wastewater

Abstract

The application belongs to the technical field of wastewater multistage treatment, and particularly relates to a layered purification and recycling device for water-based chemical production wastewater, which comprises a platform plate, a pretreatment pool, a first biochemical pool, a second biochemical pool and a deep treatment pool are sequentially arranged on the platform plate in a clockwise direction, water diversion devices are arranged between the pretreatment pool and the first biochemical pool, the first biochemical pool and the second biochemical pool, and the second biochemical pool and the deep treatment pool, an inner lining body is embedded in the second biochemical pool, a plurality of U-shaped frames are fixedly connected to the top of the inner lining body, and the inner lining body is fixedly connected to the top of the second biochemical pool through the plurality of U-shaped frames, in the application, secondary oxygenation is realized by combining mechanical lifting with natural water drop, the dissolved oxygen concentration is significantly improved, the activity of aerobic microorganisms is enhanced, the organic matter degradation efficiency is improved, the aged biofilm is periodically removed through hydraulic flushing, the growth of new film is promoted, and long-term and efficient operation of the system is maintained.

Description

Technical Field

[0001] This invention belongs to the field of multi-stage wastewater treatment technology, specifically a stratified purification, recycling and reuse device for water-based chemical production wastewater. Background Technology

[0002] Waterborne chemical production wastewater refers to process wastewater, equipment cleaning wastewater, and other auxiliary production wastewater generated during the production of waterborne coatings, waterborne resins (such as acrylic emulsions, epoxy dispersions, and polyurethane dispersions), waterborne inks, and other waterborne chemical products. This type of wastewater is characterized by high pollutant concentrations, complex compositions, and poor biodegradability, making it a key and challenging area in industrial wastewater treatment.

[0003] Existing technologies disclose several invention patents in the field of multi-stage wastewater treatment. Among them, invention patent CN109422413A discloses a water-based paint wastewater treatment device. The device is characterized by pipelines sequentially connecting a collection tank, a pH adjustment tank, a coagulation sedimentation tank, an advanced oxidation tank, a UASB tank, an SBR tank, an MBBR tank, and a product water tank. The sludge generated at each stage is treated, and the filtrate is recycled. The sludge cake is transported off-site using the aforementioned technical solution. This water-based paint wastewater treatment device treats water-based paint wastewater through pH adjustment, coagulation sedimentation, and advanced oxidation, followed by sequential treatment in UASB, SBR, and MBBR tanks. The effluent can be discharged or reused, reducing production costs, minimizing environmental pollution, and conserving water resources. However, existing water-based chemical production wastewater stratified purification and recycling devices still have certain limitations in actual operation. When treating high-concentration, high-viscosity wastewater, the bubbles produced by traditional fixed aeration heads are large in size and rise too quickly, causing oxygen to escape from the water surface before it is fully dissolved.

[0004] Based on this, the present invention designs a layered purification, recycling and reuse device for water-based chemical production wastewater to solve the above problems. Summary of the Invention

[0005] To overcome the shortcomings of existing technologies, this invention proposes a stratified purification, recycling, and reuse device for water-based chemical production wastewater. This invention primarily addresses the limitations of existing stratified purification and recycling devices for water-based chemical production wastewater in practical operation. For example, when treating high-concentration, high-viscosity wastewater, the bubbles produced by traditional fixed aeration heads are large in size and rise too quickly, causing oxygen to escape from the water surface before it is fully dissolved.

[0006] The technical solution adopted by this invention to solve its technical problem is: a layered purification, recycling and reuse device for water-based chemical production wastewater, including a platform plate. A pretreatment tank, a first biochemical tank, a second biochemical tank and a deep treatment tank are arranged sequentially in a clockwise direction on the platform plate. Water intake devices are provided between the pretreatment tank and the first biochemical tank, the first biochemical tank and the second biochemical tank, and the second biochemical tank and the deep treatment tank. An inner liner is embedded inside the second biochemical tank. Multiple U-shaped frames are fixedly connected to the top of the inner liner. The inner liner is fixedly connected to the top of the second biochemical tank through the multiple U-shaped frames. A biofilm is installed on the inner sidewall of the U-shaped frames. The bottom of the outer wall of the second biological tank is provided with a transmission port. The top and bottom of the inner wall of the transmission port are provided with sealing grooves. An inner core is rotatably connected in the sealing groove. A sealing ring is provided between the outer and inner ring surfaces of the inner core and the two sealing grooves. A lower support ring is fixedly connected to the inner ring surface of the inner core. An upper support ring is provided above the lower support ring. Multiple support shafts arranged in a ring array are fixedly connected to the bottom of the upper support ring. A first helical blade is wound around the multiple support shafts. The bottom ends of the multiple support shafts are all located at the top of the lower support ring. A drive device for driving the inner core to rotate is provided on the outer wall of the second biological tank.

[0007] Preferably, the driving device includes a gear ring fixedly sleeved on the outer ring surface of the inner core, a gear meshing on the tooth surface of the gear ring, a first frame fixedly connected to the outer wall of the second biochemical tank, a wheel axle rotatably connected to the upper part of the first frame, the gear fixedly sleeved on the wheel axle, a first motor installed at the bottom of the first frame, and the bottom end of the wheel axle fixedly connected to the output shaft of the first motor. The outer wall of the second biochemical tank is connected to multiple bridge plates arranged in a ring array at the corresponding transmission port.

[0008] Preferably, a sliding sleeve is snapped onto the biofilm, and a stirring shaft is slidably connected inside the sliding sleeve; A second frame is fixedly connected to the top of the second biochemical tank. A stirring transmission device is installed on the top of the second frame. A spline is provided on the output shaft of the stirring transmission device. A transmission groove that cooperates with the spline is opened at the top of the stirring shaft. The output shaft of the stirring transmission device is slidably connected to the transmission groove through the spline. A second helical blade is wound and connected to the stirring shaft below the biofilm.

[0009] Preferably, the inner bottom of the second biochemical tank is connected to a directional sleeve, and the bottom end of the stirring shaft is slidably connected inside the directional sleeve; An inclined blade is fixedly connected to the stirring shaft below the second spiral blade.

[0010] Preferably, the first spiral blade is provided with a plurality of second micropores evenly distributed on it, and the inner liner is provided with first micropores.

[0011] Preferably, each of the support shafts has a clamping groove at its bottom end, a ball is fitted inside the clamping groove, the bottom end of the support shaft is tumblingly connected to the top of the lower support ring through the ball, and an oil storage groove is formed on the inner wall of the clamping groove. A spring is fitted onto the support shaft. One end of the spring is fixedly connected to the top of the lower support ring, and the other end of the spring is fixedly connected to the shaft surface of the support shaft.

[0012] Preferably, the inner wall of the second biochemical tank is fitted with an outer ring body, and the inner wall of the outer ring body is provided with an annular groove. A slider is slidably connected to each support shaft in the annular groove. An umbrella-shaped shaft is rotatably connected to the slider through a pin. The other end of the umbrella-shaped shaft is rotatably connected to an adapter through a pin. Multiple adapters are fixedly connected to the outer ring surface of the upper support body.

[0013] Preferably, an adapter is rotatably connected to the top of the stirring shaft, and a cylinder is installed on the top of the second frame, with the telescopic end of the cylinder fixedly connected to the top of the adapter.

[0014] The beneficial effects of this invention are as follows: 1. In this invention, secondary oxygenation is achieved by combining mechanical lifting with natural cascading, which significantly increases the dissolved oxygen concentration, enhances the activity of aerobic microorganisms, improves the degradation efficiency of organic matter, and periodically removes aging biofilm by hydraulic flushing, promotes the growth of new biofilm, and maintains the long-term efficient operation of the system.

[0015] 2. In this invention, natural reoxygenation by utilizing elevation difference can reduce the intensity of bottom aeration, thereby reducing the energy consumption of the aeration system while ensuring treatment effect. The double helix blades rotate in opposite directions to form convection circulation, eliminating dead zones and enhancing the mixing efficiency between upper and lower layers and the diffusion efficiency of pollutants to the biofilm.

[0016] 3. In this invention, the shear force generated by the reverse rotation prevents excessive growth and blockage of the biofilm, maintains system stability, and responds to fluctuations in water quality and quantity by adjusting the rotation speed, keeping the hydraulic conditions in the pool stable and improving the robustness of the system. The inclined blades deliver air bubbles in a directional manner, improving the three-phase contact efficiency of air bubbles, water flow and biofilm, extending the air bubble path and residence time, improving the oxygen dissolution and transfer efficiency, and reducing short-circuiting and dead zones. Attached Figure Description

[0017] The invention will now be further described with reference to the accompanying drawings.

[0018] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram of the structure of the inner liner in this invention; Figure 3This is a schematic diagram of the structure of the second biochemical tank in this invention; Figure 4 In this invention Figure 3 A schematic diagram of the three-dimensional structure viewed from an upward angle; Figure 5 In this invention Figure 3 A cross-sectional view of the three-dimensional structure; Figure 6 This is a cross-sectional view of the support shaft in this invention; Figure 7 This is the present invention. Figure 5 Enlarged structural diagram at point A; Figure 8 This is a schematic diagram of the internal structure of the second biochemical tank in this invention; Figure 9 This is the present invention. Figure 6 Enlarged structural diagram at point B; Figure 10 This is the present invention. Figure 8 Enlarged structural diagram at point C.

[0019] In the diagram: 1. Platform plate; 2. Pretreatment tank; 3. First biological treatment tank; 4. Second biological treatment tank; 5. Advanced treatment tank; 6. Water intake device; 7. Inner liner; 8. U-shaped frame; 9. Biofilm; 10. Sealing groove; 11. Sealing ring; 12. Inner core; 13. Lower support ring; 14. Upper support ring; 15. Support shaft; 16. First helical blade; 17. Gear ring; 18. First micropore; 19. Axle; 20. Gear; 21. First frame; 22. Motor; 23. 24. Bridge plate; 25. Sliding sleeve; 26. Stirring shaft; 27. Second frame; 28. Stirring transmission device; 29. ​​Second spiral blade; 30. Inclined blade; 31. Orientation sleeve; 32. Second micro-hole; 33. Transmission groove; 34. Spline; 35. Adapter seat; 36. Cylinder; 37. Clamp groove; 38. Ball bearing; 39. Oil reservoir; 40. Outer ring body; 41. Annular groove; 42. Slider; 43. Umbrella-shaped shaft; 44. Adapter; 45. Spring; 46. Transmission port. Detailed Implementation

[0020] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below in conjunction with specific embodiments.

[0021] like Figures 1 to 10The water-based chemical production wastewater stratified purification and recycling device includes a platform plate 1. A pretreatment tank 2, a first biochemical tank 3, a second biochemical tank 4 and a deep treatment tank 5 are arranged sequentially in a clockwise direction on the platform plate 1. Water intake devices 6 are provided between the pretreatment tank 2 and the first biochemical tank 3, between the first biochemical tank 3 and the second biochemical tank 4, and between the second biochemical tank 4 and the deep treatment tank 5. An inner liner 7 is embedded inside the second biochemical tank 4. Multiple U-shaped frames 8 are fixedly connected to the top of the inner liner 7. The inner liner 7 is fixedly connected to the top of the second biochemical tank 4 through the multiple U-shaped frames 8. A biofilm 9 is installed on the inner side wall of the U-shaped frames 8. The bottom of the outer wall of the second biological tank is provided with a transmission port 45. The top and bottom of the inner wall of the transmission port 45 are provided with sealing grooves 10. An inner core 12 is rotatably connected in the sealing groove 10. A sealing ring 11 is provided between the outer and inner ring surfaces of the inner core 12 and the two sealing grooves 10. A lower support ring 13 is fixedly connected to the inner ring surface of the inner core 12. An upper support ring 14 is provided above the lower support ring 13. A plurality of support shafts 15 arranged in a ring array are fixedly connected to the bottom of the upper support ring 14. A first spiral blade 16 is wound around the plurality of support shafts 15. The bottom ends of the plurality of support shafts 15 are all located at the top of the lower support ring 13. A drive device for driving the inner core 12 to rotate is provided on the outer wall of the second biological tank 4. The drive device includes a gear ring 17 fixedly sleeved on the outer ring surface of the inner core 12, a gear 20 meshing on the tooth surface of the gear ring 17, a first frame 21 fixedly connected to the outer wall of the second biochemical tank 4, a wheel axle 19 rotatably connected to the upper part of the first frame 21, the gear 20 fixedly sleeved on the wheel axle 19, a first motor 22 installed at the bottom of the first frame 21, and the bottom end of the wheel axle 19 fixedly connected to the output shaft of the first motor 22. The outer wall of the second biochemical pool 4 is connected to multiple bridging plates 23 arranged in a ring array at the corresponding transmission port 45.

[0022] This embodiment specifically involves: injecting water-based chemical production wastewater into pretreatment tank 2; adding chemical agents to disrupt the emulsified state of resins and pigments in the wastewater, causing them to coagulate into separable suspended solids; after this treatment, most of the suspended solids and some chemical oxygen demand (COD) in the wastewater are removed; controlling the water intake device 6 between pretreatment tank 2 and the first biological treatment tank 3, the pretreated wastewater is introduced into the first biological treatment tank 3; in the first biological treatment tank 3, anaerobic or facultative bacteria decompose the large molecular organic matter in the wastewater that is difficult to biodegrade into smaller molecular organic matter, thereby improving the biodegradability of the wastewater; controlling the water intake device 6 between the first biological treatment tank 3 and the second biological treatment tank 4, the pretreated wastewater is introduced into the second biological treatment tank 4. Wastewater from the initial treatment is introduced into the second biological treatment tank 4. The second biological treatment tank 4 is filled with packing material for microbial attachment, and multiple aeration heads are installed at the bottom of the tank. Through aeration and oxygenation, the biofilm 9 attached to the surface of the packing material efficiently adsorbs and degrades organic matter in the water. A water intake device 6 between the second biological treatment tank 4 and the advanced treatment tank 5 injects the oxidized wastewater into the advanced treatment tank 5. The sand filtration and activated carbon adsorption system in the advanced treatment tank 5 performs final purification of the wastewater. The effluent after multi-stage treatment meets recycling standards. After being injected into the second biological treatment tank 4, the wastewater enters the aeration treatment stage. During this stage, the first motor 22 is controlled to operate, and its output... The shaft drives the gear 20 to rotate via the axle 19. The gear 20 and the gear ring 17 transmit torque towards the inner core 12. The lower support ring 13 on the inner surface of the gear ring 17 drives the first spiral blade 16 to rotate within the gap between the liner 7 and the second biological tank 4 via multiple support shafts 15. This causes the wastewater at the bottom of the second biological tank 4 to flow upwards. When the wastewater is pushed to its highest point by the first spiral blade 16, it quickly falls towards the biofilm 9, forming a natural waterfall due to the elevation difference. During the fall and impact on the water surface, the water flow is forcibly dispersed, significantly increasing the contact area and contact time with air, achieving secondary oxygenation of the water body. This is achieved through mechanical lifting and... The combination of natural cascading water and biological contact oxidation introduces secondary oxygenation to increase the dissolved oxygen concentration in the water and enhance the metabolic activity of aerobic microorganisms. During the cascading process, the water flow is broken into fine droplets or thin water films, which greatly increases the gas-liquid contact area and prolongs the mass transfer time of oxygen into the water, thereby improving oxygen utilization. The periodically falling water flow generates a hydraulic scouring effect on the surface of the biofilm 9, which helps to remove the aging biofilm 9, promotes the growth of new biofilm 9, and maintains the system's high-efficiency degradation capacity. Natural reoxygenation is achieved by utilizing the elevation difference, which can appropriately reduce the oxygen supply intensity of the bottom aeration heads and reduce the energy consumption of the aeration system while ensuring the treatment effect.

[0023] Specifically, a sliding sleeve 24 is snapped onto the biofilm 9, and a stirring shaft 25 is slidably connected inside the sliding sleeve 24; The top of the second biochemical tank 4 is fixedly connected to a second frame 26. A stirring transmission device 27 is installed on the top of the second frame 26. A spline 33 is provided on the output shaft of the stirring transmission device 27. A transmission groove 32 that cooperates with the spline 33 is opened at the top of the stirring shaft 25. The output shaft of the stirring transmission device 27 is slidably connected to the transmission groove 32 through the spline 33. A second spiral blade 28 is wound and connected on the stirring shaft 25 below the biofilm 9.

[0024] Specifically, this embodiment involves controlling the operation of the second motor 22, whose output drives the stirring shaft 25 to rotate within the sliding sleeve 24, thereby driving the second spiral blade 28 located below the biofilm 9 to rotate. Simultaneously, the rotation direction of the second spiral blade 28 is opposite to that of the first spiral blade 16. This counter-rotation of the second spiral blade 28 and the first spiral blade 16 creates two forced water flows in opposite directions within the biological treatment tank, promoting efficient mixing between the upper and lower layers of the water and eliminating mass transfer dead zones. The counter-current water flow generated by the second spiral blade 28 located below the biofilm 9 increases the flow velocity and frequency of wastewater passing through the surface of the biofilm 9. The reverse rotation enhances the diffusion process of pollutants into the biofilm 9. The shear force generated by the reverse rotation helps control the excessive growth of the biofilm 9 and prevents clogging. At the same time, it promotes the shedding of the aged biofilm 9 and the regeneration of the new biofilm, maintaining the long-term stable operation of the system. It forms a countercurrent complement with the upflow formed by the first helical blade 16, improving the vertical uniformity of dissolved oxygen distribution in the second biological tank 4 and increasing oxygen utilization efficiency. The reverse operation of the first helical blade 16 and the second helical blade 28 can maintain stable hydraulic conditions in the second biological tank 4 by adjusting the rotation speed when the influent water quality or quantity fluctuates, thus enhancing the shock resistance of the biological system.

[0025] Specifically, the inner bottom of the second biochemical tank 4 is connected to a directional sleeve 30, and the bottom end of the stirring shaft 25 is slidably connected inside the directional sleeve 30; An inclined blade 29 is fixedly connected to the stirring shaft 25 below the second spiral blade 28; Multiple second micropores 31 are evenly provided on the first helical blade 16, and first micropores 18 are provided on the inner liner 7. Each support shaft 15 has a clamping groove 36 at its bottom end, and a ball bearing 37 is fitted inside the clamping groove 36. The bottom end of the support shaft 15 is connected to the top of the lower support ring 13 by the ball bearing 37. An oil storage groove 38 is provided on the inner wall of the clamping groove 36. A spring 44 is sleeved on the support shaft 15. One end of the spring 44 is fixedly connected to the top of the lower support ring 13, and the other end of the spring 44 is fixedly connected to the shaft surface of the support shaft 15. The inner wall of the second biochemical tank 4 is fitted with an outer ring body 39. The inner wall of the outer ring body 39 is provided with an annular groove 40. A slider 41 is slidably connected to each support shaft 15 in the annular groove 40. An umbrella-shaped shaft 42 is rotatably connected to the slider 41 through a pin. The other end of the umbrella-shaped shaft 42 is rotatably connected to an adapter 43 through a pin. Multiple adapters 43 are fixedly connected to the outer ring surface of the upper support body. The top of the stirring shaft 25 is rotatably connected to the adapter 34, and the top of the second frame 26 is equipped with a cylinder 35, the telescopic end of the cylinder 35 being fixedly connected to the top of the adapter 34.

[0026] Specifically, in this embodiment: during the rotation of the stirring shaft 25, the inclined blades 29 are simultaneously rotated; the rotating inclined blades 29 guide and transport the airflow or bubbles generated by aeration towards the direction of the first spiral blade 16. The inclined blades 29 actively direct the bubbles or airflow generated by aeration to the area of ​​the first spiral blade 16, reducing the disorderly diffusion of bubbles in the tank and allowing oxygen to more concentratedly serve the biofilm 9 reaction zone. Through directional transport, the contact frequency and intensity between the bubbles, the water flow driven by the first spiral blade 16, and the biofilm 9 carrier are significantly increased, which is conducive to the efficient degradation of pollutants in the aerobic environment. The rotation of the inclined blades 29 introduces local directional flow in the biological tank, so that the aeration airflow and the main circulating water flow form a reasonable superposition and coordination, improving the overall flow field distribution, reducing hydraulic short-circuiting and dead zones, and transporting bubbles in a specific direction, which can prolong the movement path and residence time of bubbles in the water, thereby improving the oxygen solubility and transfer efficiency; multiple first micropores 18 are opened on the inner liner 7, and simultaneously, the first spiral blades 16 are uniformly opened Multiple second micropores 31 are provided. The first micropore 18 and the second micropores 31 together form a secondary cutting and dispersion channel for bubbles. During the rising process, the bubbles generated by aeration pass through the two layers of micropores in sequence and are repeatedly refined, which significantly increases the gas-liquid contact area and improves the oxygen dissolution rate. The structure of the second micropores 31 has a uniform distribution effect on the water flow, making the wastewater flowing through the first spiral blade 16 and the inner liner 7 more evenly distributed, reducing local high-speed zones or dead zones, which is conducive to the full contact between the biofilm 9 and pollutants. The microbubbles released by the second micropores 31 can form local disturbances around the orifice, inhibiting the deposition of suspended matter on the orifice and blade surface, delaying the excessive growth of the biofilm 9, and maintaining the unobstructed flow section. The jet and shearing effect generated when the bubbles pass through the second micropores 31 enhances the mixing intensity at the microscale of the water body, helps to break the concentration boundary layer in the water body, and promotes the diffusion of pollutants to the surface of the biofilm 9. Under the premise of achieving the same dissolved oxygen level, the refining effect of the first micropore 18 structure on the bubbles can improve the oxygen transfer efficiency, thereby allowing for an appropriate reduction in aeration intensity and achieving energy-saving operation. During the process of the lower support ring 13 driving the first helical blade 16 to rotate via multiple support shafts 15, the first helical blade 16 tilts due to the resistance of wastewater, and the torsion spring 44 causes it to undergo elastic deformation. During this process, the bottom end of the support shaft 15 rolls on the top surface of the lower support ring 13 via balls 37. Simultaneously, the grease in the oil reservoir 38 lubricates the balls 37 to further reduce wear between the support shaft 15 and the lower support ring 13. The first helical blade 16 tilts controllably under the resistance of wastewater, and the torsion spring 44 undergoes elastic deformation, allowing the first helical blade 16 to adjust according to the hydraulic load. The dynamic adjustment angle of the load achieves adaptive hydraulic balance, improving the stability of system operation. The bottom end of the support shaft 15 rolls on the top surface of the lower support ring 13 through the ball bearings 37, converting sliding friction into rolling friction, significantly reducing the frictional resistance of the contact surface and reducing drive energy consumption. The grease in the oil reservoir 38 continuously lubricates the ball bearings 37, forming a stable oil film, effectively reducing the direct contact wear between the ball bearings 37 and the support shaft 15 and the lower support ring 13, and extending the service life of key transmission components. The rolling of the ball bearings 37 and the grease work together to make the relative movement between the support shaft 15 and the lower support ring 13 smoother and more fluid. During the rotation of the upper support ring 14 driven by multiple support shafts 15, the upper support ring 14 simultaneously drives multiple adapters 43 to move in a circumferential direction. Each adapter 43 applies a pushing or pulling force to its connected umbrella-shaped shaft 42, causing the other end of the umbrella-shaped shaft 42 to rotate around the connected slider 41 and drive the slider 41 to slide within the annular groove 40, thereby achieving the limiting function of the first helical blade 16. Through the linkage between the umbrella-shaped shaft 42, the slider 41, and the annular groove 40, dynamic constraints are applied to the motion trajectory of the first helical blade 16 during rotation, preventing it from deviating from the predetermined working path and ensuring operational stability. The adapters 43 can alternately apply pushing and pulling forces to the umbrella-shaped shaft 42, enabling the system to... Equipped with bidirectional force transmission capability, it adapts to the reciprocating or oscillating motion requirements of the first helical blade 16 under different working conditions. Multiple sets of adapters 43 and umbrella-shaped shaft 42 are evenly arranged along the circumference to form a symmetrical force system, so that the rotational force of the upper support ring 14 can be evenly transmitted to the slider 41, avoiding jamming or uneven wear caused by uneven local force. The sliding limit mechanism of the slider 41 in the annular groove 40 can effectively suppress the irregular oscillation of the first helical blade 16 under hydraulic impact or load fluctuation, and improve the mechanism's resistance to external disturbances. Through the cooperation of the slider 41 and the annular groove 40, the movement of the end of the umbrella-shaped shaft 42 is constrained within the predetermined slide, reducing the motion error caused by redundant degrees of freedom and improving the transmission accuracy.

[0027] During operation, water-based chemical production wastewater is injected into pretreatment tank 2. Chemical agents are added to disrupt the emulsified state of resins and pigments in the wastewater, causing them to coagulate into separable suspended solids. This treatment removes most of the suspended solids and some of the chemical oxygen demand (COD) from the wastewater. A water inlet device 6, controlling the flow between pretreatment tank 2 and the first biological treatment tank 3, introduces the pretreated wastewater into the first biological treatment tank 3. In the first biological treatment tank 3, anaerobic or facultative bacteria decompose the large, difficult-to-biodegrade organic molecules in the wastewater into smaller organic molecules, thereby improving the biodegradability of the wastewater. The flow between the first and second biological treatment tanks is controlled. The water intake device 6 between the two pools introduces the wastewater that has completed hydrolysis and acidification treatment into the second biological treatment pool 4. The second biological treatment pool 4 is filled with packing material for microbial attachment, and multiple aeration heads are installed at the bottom of the second biological treatment pool 4. Through aeration and oxygenation, the biofilm 9 attached to the surface of the packing material efficiently adsorbs and degrades organic matter in the water. The water intake device 6 between the second biological treatment pool 4 and the deep treatment pool 5 injects the wastewater that has completed oxidation treatment into the deep treatment pool 5. The sand filtration and activated carbon adsorption system in the deep treatment pool 5 performs final purification of the wastewater. The effluent after multi-stage treatment can meet the recycling standards. After the wastewater is injected into the second biological treatment tank 4, it enters the aeration treatment stage. During this stage, the first motor 22 is controlled to operate, and its output shaft drives the gear 20 to rotate via the wheel axle 19. The gear 20 and the gear ring 17 transmit torque towards the inner core 12. The lower support ring 13 on the inner surface of the gear ring 17 drives the first spiral blade 16 through multiple support shafts 15, causing it to rotate within the gap between the liner 7 and the second biological treatment tank 4. This causes the wastewater at the bottom of the tank to flow upwards. When the wastewater is sent to the highest point by the first spiral blade 16, it quickly falls towards the biofilm 9, forming a natural waterfall due to the elevation difference. During the fall and impact on the water surface, the water flow is forcibly dispersed, significantly increasing the contact area and time with air, thus achieving [the desired effect]. Secondary oxygenation of the water body is achieved through a combination of mechanical lifting and natural cascading. This secondary oxygenation is introduced on the basis of biological contact oxidation process to increase the dissolved oxygen concentration in the water body and enhance the metabolic activity of aerobic microorganisms. During the cascading process, the water flow is broken into fine water droplets or thin water films, which greatly increases the gas-liquid contact area and prolongs the mass transfer time of oxygen into the water body, thereby improving oxygen utilization. The periodically falling water flow generates a hydraulic scouring effect on the surface of biofilm 9, which helps to remove aging biofilm 9, promotes the growth of new biofilm 9, maintains the system's high-efficiency degradation capacity, and utilizes the elevation difference to achieve natural reoxygenation. This can appropriately reduce the oxygen supply intensity of the bottom aeration head and reduce the energy consumption of the aeration system while ensuring the treatment effect. The second motor 22 is controlled to operate, and its output end drives the stirring shaft 25 to rotate within the sliding sleeve 24, thereby driving the second spiral blade 28 located below the biofilm 9 to rotate. The rotation direction of the second spiral blade 28 is opposite to that of the first spiral blade 16, forming two forced water flows in opposite directions in the biological treatment tank. This promotes efficient mixing between the upper and lower layers of water and eliminates mass transfer dead zones. The countercurrent water flow generated by the second spiral blade 28 located below the biofilm 9 can increase the flow rate and frequency of wastewater passing through the surface of the biofilm 9, and strengthen the diffusion process of pollutants into the interior of the biofilm 9. The shear force generated by the countercurrent rotation helps to control the excessive growth of the biofilm 9 and prevent blockage. At the same time, it promotes the shearing of the aged biofilm 9 and the regeneration of the new biofilm, maintaining the long-term stable operation of the system. It forms a countercurrent complement with the upflow formed by the first spiral blade 16, improving the vertical distribution uniformity of dissolved oxygen in the second biological treatment tank 4 and increasing oxygen utilization efficiency. The countercurrent operation of the first spiral blade 16 and the second spiral blade 28 can maintain stable hydraulic conditions in the tank by adjusting the rotation speed when the influent water quality or quantity fluctuates, thereby enhancing the shock resistance of the biological treatment system. During the rotation of the stirring shaft 25, the inclined blades 29 are simultaneously rotated. The rotating inclined blades 29 guide and transport the airflow or bubbles generated by aeration towards the direction of the first spiral blade 16, actively reducing the disorderly diffusion of bubbles in the tank and making oxygen more concentrated in the biofilm 9 reaction zone. Through directional transport, the contact frequency and intensity between the bubbles, the water flow driven by the first spiral blade 16, and the biofilm 9 carrier are significantly increased, which is conducive to the efficient degradation of pollutants in the aerobic environment. The rotation of the inclined blades 29 introduces local directional flow in the biological tank, so that the aeration airflow and the main circulating water flow form a reasonable superposition and coordination, improve the overall flow field distribution, reduce hydraulic short-circuiting and dead zones, and transport the bubbles in a specific direction, which can prolong the movement path and residence time of the bubbles in the water, thereby improving the oxygen solubility and transfer efficiency.

[0028] The embodiments of the present invention have been described with reference to the accompanying drawings. However, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other modifications under the guidance of the present invention without departing from the spirit and scope of the claims. All of these modifications are within the protection scope of the present invention.

Claims

1. A stratified purification, recycling, and reuse device for water-based chemical production wastewater, comprising a platform plate, wherein a pretreatment tank, a first biological treatment tank, a second biological treatment tank, and a deep treatment tank are sequentially arranged on the platform plate in a clockwise direction, and water intake devices are provided between the pretreatment tank and the first biological treatment tank, the first biological treatment tank and the second biological treatment tank, and the second biological treatment tank and the deep treatment tank; characterized in that: The second biological tank is equipped with an inner liner, and multiple U-shaped frames are fixedly connected to the top of the inner liner. The inner liner is fixedly connected to the top of the second biological tank through the multiple U-shaped frames, and a biofilm is installed on the inner side wall of the U-shaped frames. The bottom of the outer wall of the second biological tank is provided with a transmission port. The top and bottom of the inner wall of the transmission port are provided with sealing grooves. An inner core is rotatably connected in the sealing groove. A sealing ring is provided between the outer and inner ring surfaces of the inner core and the two sealing grooves. A lower support ring is fixedly connected to the inner ring surface of the inner core. An upper support ring is provided above the lower support ring. Multiple support shafts arranged in a ring array are fixedly connected to the bottom of the upper support ring. A first helical blade is wound around the multiple support shafts. The bottom ends of the multiple support shafts are all located at the top of the lower support ring. A drive device for driving the inner core to rotate is provided on the outer wall of the second biological tank.

2. The water-based chemical production wastewater stratified purification and recycling device according to claim 1, characterized in that: The driving device includes a gear ring fixedly sleeved on the outer ring surface of the inner core, with gears meshing on the tooth surface of the gear ring. The outer wall of the second biochemical tank is fixedly connected to a first frame. A wheel axle is rotatably connected to the upper part of the first frame. The gear is fixedly sleeved on the wheel axle. A first motor is installed at the bottom of the first frame. The bottom end of the wheel axle is fixedly connected to the output shaft of the first motor. The outer wall of the second biochemical tank is connected to multiple bridge plates arranged in a ring array at the corresponding transmission port.

3. The water-based chemical production wastewater stratified purification and recycling device according to claim 2, characterized in that: A sliding sleeve is snapped onto the biofilm, and a stirring shaft is slidably connected inside the sliding sleeve; A second frame is fixedly connected to the top of the second biochemical tank. A stirring transmission device is installed on the top of the second frame. A spline is provided on the output shaft of the stirring transmission device. A transmission groove that cooperates with the spline is opened at the top of the stirring shaft. The output shaft of the stirring transmission device is slidably connected to the transmission groove through the spline. A second helical blade is wound and connected to the stirring shaft below the biofilm.

4. The water-based chemical production wastewater stratified purification and recycling device according to claim 3, characterized in that: The inner bottom of the second biochemical tank is connected to a directional sleeve, and the bottom end of the stirring shaft is slidably connected inside the directional sleeve; An inclined blade is fixedly connected to the stirring shaft below the second spiral blade.

5. The water-based chemical production wastewater stratified purification and recycling device according to claim 4, characterized in that: The first spiral blade has a plurality of second micropores evenly distributed on it, and the inner liner has first micropores distributed on it.

6. The water-based chemical production wastewater stratified purification and recycling device according to claim 5, characterized in that: Each of the support shafts has a clamping groove at its bottom end, and a ball is fitted inside the clamping groove. The bottom end of the support shaft is rolled to the top of the lower support ring through the ball. An oil storage groove is formed on the inner wall of the clamping groove. A spring is fitted onto the support shaft. One end of the spring is fixedly connected to the top of the lower support ring, and the other end of the spring is fixedly connected to the shaft surface of the support shaft.

7. The water-based chemical production wastewater stratified purification and recycling device according to claim 6, characterized in that: The inner wall of the second biochemical tank is fitted with an outer ring body. The inner wall of the outer ring body has an annular groove. A slider is slidably connected to each support shaft in the annular groove. An umbrella-shaped shaft is rotatably connected to the slider through a pin. The other end of the umbrella-shaped shaft is rotatably connected to an adapter through a pin. Multiple adapters are fixedly connected to the outer ring surface of the upper support body.

8. The water-based chemical production wastewater stratified purification and recycling device according to claim 7, characterized in that: The top end of the stirring shaft is rotatably connected to an adapter, and a cylinder is installed on the top of the second frame. The telescopic end of the cylinder is fixedly connected to the top of the adapter.

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