A high-precision treatment and resource utilization system for fluorine-containing wastewater

Abstract

The present invention relates to the technical field of fluorine-containing wastewater treatment devices, and discloses a high-precision treatment and resource utilization system for fluorine-containing wastewater. It includes an adsorption-separation-regeneration-recycling system and a PLC automatic control system. One end of the adsorption-separation-regeneration-recycling system is provided with a base. One side of the upper surface of the base is equipped with an adsorption device. One end of the adsorption device is provided with a water inlet, and one end of the adsorption device is provided with a water outlet. The upper end of the adsorption device is equipped with a separation recovery-recycling device. The upper surface of the base is provided with a regeneration device. One end of the regeneration device is provided with a filtration device. One end of the upper surface of the base is provided with a sediment collection box. By using magnetic adsorption materials and an optimized adsorption-separation-regeneration-recycling system, it can achieve an efficient fluorine removal effect, reduce the fluoride ion concentration in the wastewater to below 1 mg / L, not only solve the efficiency problem of traditional methods in treating low-concentration fluorine-containing wastewater, but also ensure that the wastewater meets strict discharge standards.

Description

Technical Field

[0001] The present invention belongs to the technical field of fluorine-containing wastewater treatment devices, and particularly relates to a high-precision treatment and resource utilization system for fluorine-containing wastewater. Background Art

[0002] Fluorine-containing wastewater mainly comes from industries such as fluoride salt production, electrolytic aluminum industry, glass manufacturing, electronic semiconductors, surface treatment, and refrigerant production. The fluoride ion concentration in these wastewaters is as high as 100 - 1000 mg / L, which has strong corrosiveness and toxicity, and poses a great potential hazard to water bodies, soil environments, and the human body.

[0003] The existing methods for treating fluorine-containing wastewater mainly include chemical precipitation method, coagulation precipitation method, and adsorption method. The chemical precipitation method converts fluoride ions into calcium fluoride precipitate by adding lime or calcium chloride, and the coagulation precipitation method generates flocs by adding coagulants such as aluminum salts and iron salts to adsorb fluoride ions. These methods have good treatment effects on high-concentration fluorine-containing wastewater, but the defluorination accuracy is low, and the fluoride ion content in the effluent is generally about 20 mg / L, which is difficult to meet the fluoride ion emission limit (≤10 mg / L) specified in the Comprehensive Wastewater Discharge Standard (GB 8978 - 1996), and it is easy to generate a large amount of sludge, which may cause secondary pollution and increase the subsequent treatment difficulty. The adsorption method uses the active sites on the surface of adsorbents such as activated alumina, activated carbon, and hydroxyapatite to adsorb fluoride ions, with a high efficiency of removing fluorine, and can achieve a low residual fluorine concentration. The fluoride ion concentration of the treated wastewater can be reduced to less than 1 mg / L, which can meet the requirements for the treatment accuracy of fluorine-containing wastewater. In addition, compared with other methods, the adsorption method usually does not require complex equipment and operation processes, has simple equipment and is easy to maintain, has low costs, and is suitable for various types of fluorine-containing wastewater and treatment facilities of various scales.

[0004] However, the existing adsorption methods generally have problems such as easy loss of adsorption materials, difficult separation, difficult regeneration after saturation, complex and time-consuming and energy-consuming regeneration processes, easy occurrence of secondary pollution during the regeneration process, and low automation degree of adsorption equipment. Summary of the Invention

[0005] The purpose of the present invention is to provide a high-precision treatment and resource utilization system for fluorine-containing wastewater in order to solve the problems existing in the existing adsorption methods, such as easy loss of adsorption materials, difficult separation, difficult regeneration after saturation, complex and time-consuming and energy-consuming regeneration processes, easy occurrence of secondary pollution during the regeneration process, and low automation degree of adsorption equipment.

[0006] The technical solution adopted by the present invention is as follows: A high-precision treatment and resource utilization system for fluorine-containing wastewater, comprising an adsorption-separation-regeneration-recycling system and a PLC automatic control system. One end of the adsorption-separation-regeneration-recycling system is provided with a base. On one side of the upper surface of the base, an adsorption device is installed. One end of the adsorption device is provided with a water inlet, and one end of the adsorption device is provided with a water outlet. At the upper end of the adsorption device, a separation recovery-recycling device is installed. One end of the separation recovery-recycling device is installed with a servo motor. At the upper end of the servo motor, a rotating shaft is provided. At the lower end of the separation recovery-recycling device, a square rotating plate is provided. On the surface of the square rotating plate, a through-type circular through-hole corresponding to the circular hole is opened. On the upper surface of the square rotating plate, a number of separation recovery devices corresponding to the through-type circular through-hole are installed. One end of the square rotating plate is provided with a semi-circular hole. One side of the semi-circular hole is welded to the outer surface of the rotating shaft. One side of the square rotating plate is provided with a triangular bracket corresponding to the rotating shaft. The triangular bracket is connected to the rotating shaft. On the upper surface of the base, a regeneration device is provided. One end of the regeneration device is provided with a filtering device. At one end of the upper surface of the base, a sediment collection tank is provided.

[0007] By adopting the above technical solution, using a magnetic adsorption material and an optimized adsorption-separation-regeneration-recycling system, an efficient defluorination effect can be achieved, reducing the fluoride ion concentration in the wastewater to below 1 mg / L. It not only solves the efficiency problem of traditional methods in treating low-concentration fluorine-containing wastewater but also ensures that the wastewater meets strict discharge standards.

[0008] In a preferred embodiment, a cylindrical adsorption tank is arranged inside the adsorption device. Eight circular holes are opened at the upper end of the adsorption device. A baffle is arranged inside the adsorption tank. On both sides of the adsorption tank, a primary adsorption tank and a secondary adsorption tank are respectively arranged. The baffle is arranged in the middle of the primary adsorption tank and the secondary adsorption tank. Two stirring devices are installed inside the primary adsorption tank and the secondary adsorption tank.

[0009] By adopting the above technical solution, the stirring device adopts a mechanical stirring form, which can improve the contact efficiency between the magnetic adsorption material and the fluoride ions in the wastewater, prevent the adsorption material from settling or aggregating, and ensure its uniform distribution.

[0010] In a preferred embodiment, a motor a is installed at one end of the stirring device. A rotating rod is provided at one end of the motor a. Stirring rods are provided on both sides at one end of the rotating rod. Three stirring blades a are provided on the outer surface of the stirring rods. The inclination angle between the stirring blades a is set to 120°. A driving gear is provided on the outer surface of the rotating rod. A driven gear corresponding to the driving gear is provided on the outer surface of one of the stirring rods. The driving gear meshes with the driven gear. Three stirring blades b are provided on the outer surface of the bottom end of the rotating rod.

[0011] By adopting the above technical solution, after the motor a is powered on, the rotating rod drives the stirring rods, the driving gear and the stirring blades a to rotate horizontally around the rotating rod. The driving gear then drives the driven gear, and the driven gear drives the stirring blades a to rotate self - clockwise around the stirring rods, so that the stirring blades can not only rotate horizontally, but also rotate self - clockwise in the vertical direction, enabling the adsorption material to be fully dispersed in the adsorption tank.

[0012] In a preferred embodiment, a cylindrical regeneration tank with the same shape as the adsorption device is provided inside the regeneration device. Eight round holes are opened at the top of the regeneration device. The stirring device is installed on the inner wall at the upper end of the regeneration device. A flushing device is installed inside the regeneration device. Four pointed - nozzle sprayers are provided inside the flushing device. The pointed - nozzle sprayers are arranged at the lower end of the round holes, and the nozzles are at an angle of 60° towards the round holes. A chemical - adding device a and a chemical - adding device b are respectively installed on both sides at the upper end of the regeneration device.

[0013] By adopting the above technical solution, deionized water is sprayed to wash the regeneration reagent remaining on the surface of the magnetic adsorption material. The chemical - adding device a adds the regeneration reagent to desorb the magnetic adsorption material adsorbed with fluoride ions, so that the fluoride ions are transferred to the solution without changing the surface chemical properties of the magnetic material. The chemical - adding device b adds the concentration reagent, and the fluoride ions in the regeneration solution are separated through precipitation. Then, the fluoride ion precipitate is finally recovered into the precipitation collection box through the filtering device to achieve resource utilization.

[0014] In a preferred embodiment, a disc is provided inside the separation and recovery device. A motor b is installed on one side of the upper surface of the disc. A barrel - shaped wheel is provided at the upper end of the motor b. An arc - shaped sliding groove is opened on the outer surface of the barrel - shaped wheel. A column - shaped slider is slidably connected inside the arc - shaped sliding groove. A box body corresponding to the motor b is provided on one side of the upper surface of the disc. A right - hand side groove is opened on one side surface of the box body. The column - shaped slider is slidably connected inside the right - hand side groove. A round hole is opened in the middle of the disc. A hollow cylindrical bottom pipe corresponding to the round hole is provided on the lower surface of the disc. Hydraulic rods are installed on the four sides of the lower surface of the disc.

[0015] By adopting the above technical solution, under the action of the motor b, the barrel-shaped wheel can be driven to rotate, so that one end of the columnar slider slides inside the arc-shaped chute, and then the columnar slider can be driven to move inside the right groove.

[0016] In a preferred embodiment, a spring is installed inside the box body, a magnet is arranged inside the spring, a round cake pressing block is arranged at the upper end of the magnet, rectangular parallelepiped-shaped sliders are arranged on both sides of the round cake pressing block, and the columnar slider is arranged on the surface of one of the rectangular parallelepiped-shaped sliders. A left groove corresponding to the rectangular parallelepiped-shaped slider is opened on the other surface of the box body.

[0017] By adopting the above technical solution, after the motor b is powered on, it drives the barrel-shaped wheel to rotate, and the columnar slider lapped inside the arc-shaped chute on the barrel-shaped wheel slides downward accordingly. The columnar slider drives the spring and the magnet to move downward, and the magnet is pushed into the inside of the hollow cylinder bottom tube through the round hole. Subsequently, the hydraulic rod contracts, so that the hollow cylinder bottom tube structure with the magnet descends and is pushed into the adsorption device or the regeneration device.

[0018] In a preferred embodiment, the material of the magnet is a neodymium iron boron magnet.

[0019] By adopting the above technical solution, it has good magnetism and can provide strong magnetic field support. At the same time, it has good wear resistance and scratch resistance, which prolongs its service life.

[0020] In a preferred embodiment, a sedimentation chamber is opened at the lower end inside the filtering device, a filtrate chamber is opened at the upper end inside the filtering device, a filter screen is arranged between the sedimentation chamber and the filtrate chamber, a sludge suction pipe is arranged at one end of the filtering device, the sludge suction pipe is communicated with the regeneration device, a sediment discharge pipe is arranged at one end of the filtering device, the sediment discharge pipe is communicated with the sediment collection box, a reflux pipe is arranged at the upper end of the filtering device, the other end of the reflux pipe is communicated with the regeneration device, and pumps are installed at one ends of the reflux pipe, the sludge suction pipe and the sediment discharge pipe.

[0021] By adopting the above technical solution, under the action of the pump, the sediment in the regeneration device is pumped into the sedimentation chamber. The liquid filtered by the filter screen flows into the filtrate chamber and then flows back to the regeneration device through the reflux pipe, while the CaF2 sediment in the sedimentation chamber enters the sediment collection box through the sediment discharge pipe for storage.

[0022] In a preferred embodiment, the PLC automatic control system respectively sets fluoride ion sensors at the water inlet, the water outlet of the adsorption device and the regeneration device, and an electric conductivity sensor is set in the regeneration device.

[0023] By adopting the above technical solutions, the key parameters such as the concentration of F and the ionic strength of the NaCl regenerant are monitored in real time, and the full-automatic control of adsorption, regeneration, precipitation and discharge is realized, ensuring the efficient and stable operation of the defluorination system. - The concentration of and the ionic strength of the NaCl regenerant are monitored in real time, and the full-automatic control of adsorption, regeneration, precipitation and discharge is realized, ensuring the efficient and stable operation of the defluorination system.

[0024] In summary, due to the adoption of the above technical solutions, the beneficial effects of the present invention are as follows:

[0025] 1. The present invention adopts a magnetic adsorption material and an optimized adsorption-separation-regeneration-recycling system, which can achieve an efficient defluorination effect, reducing the fluoride ion concentration in the wastewater to below 1 mg / L. It not only solves the efficiency problem of traditional methods in treating low-concentration fluoride wastewater but also ensures that the wastewater meets strict discharge standards.

[0026] 2. By optimizing the design of the adsorption material and adopting a magnetic adsorption material, the present invention significantly reduces the loss and difficult separation problems of traditional adsorption materials. Through a two-stage adsorption design, gradient adsorption is achieved, improving the stability of the adsorption material, extending its service life, avoiding frequent replenishment or replacement of the adsorption material, and thus reducing the treatment cost.

[0027] 3. The present invention organically combines the adsorption device and the regeneration device to form an efficient and rapid in-situ regeneration system. This system avoids the complex, energy-consuming and labor-intensive operations in traditional regeneration technologies, greatly improves the regeneration efficiency of the adsorption material, reduces the waste of the adsorption material, and lowers the cost of the entire wastewater treatment process.

[0028] 4. The present invention converts the F in the regeneration liquid into calcium fluoride precipitate for collection. As a recyclable resource, CaF2 can be applied in multiple industrial fields. This not only avoids the secondary pollution of F to the environment but also ensures the environmental protection of the wastewater treatment process, enhancing the green environmental protection and sustainability of the wastewater treatment process. - converts the F in the regeneration liquid into calcium fluoride precipitate for collection. As a recyclable resource, CaF2 can be applied in multiple industrial fields. This not only avoids the secondary pollution of F to the environment but also ensures the environmental protection of the wastewater treatment process, enhancing the green environmental protection and sustainability of the wastewater treatment process. - to the environment and also ensures the environmental protection of the wastewater treatment process, enhancing the green environmental protection and sustainability of the wastewater treatment process.

[0029] 5. The present invention automates the key operations such as adsorption, separation and regeneration of the adsorption material, reducing manual intervention and uncertain factors, improving the flexibility and stability of the system. The automatic control not only improves the operation efficiency but also reduces human operation errors and costs, making the entire wastewater treatment process more efficient and reliable. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 is the overall schematic diagram of the high-precision treatment and resource utilization system for fluoride-containing wastewater in the present invention;

[0031] Figure 2 is the front structural schematic diagram of the adsorption-separation-regeneration-recycling system in the present invention;

[0032] Figure 3 This is a cross-sectional view of the adsorption-separation-regeneration-recycling system in the present invention;

[0033] Figure 4 This is a front structural schematic diagram of the stirring device in the present invention;

[0034] Figure 5 This is a front structural schematic diagram of the separation and recovery device in the present invention;

[0035] Figure 6 This is a front structural cross-sectional view of the separation and recovery device in the present invention;

[0036] Figure 7 This is a rear structural cross-sectional view of the separation and recovery device in the present invention;

[0037] Figure 8 This is a cross-sectional view of the filtering device in the present invention.

[0038] Reference numerals in the figure: 1. Adsorption-separation-regeneration-recycling system; 2. PLC automatic control system; 3. Base; 4. Water inlet; 5. Adsorption device; 6. Separation and recovery-recycling device; 7. Regeneration device; 8. Filtering device; 9. Precipitation collection tank; 10. Water outlet; 11. Servo motor; 12. Triangular support; 13. Rotating shaft; 14. Square rotating plate; 15. Separation and recovery device; 16. Round hole; 17. Chemical dosing device a; 18. Chemical dosing device b; 19. Sludge suction pipe; 20. Pump; 21. Return pipe; 22. Precipitation discharge pipe; 23. Baffle plate; 24. Primary adsorption tank; 25. Secondary adsorption tank; 26. Stirring device; 27. Flushing device; 28. Filter screen; 29. Motor a; 30. Rotating rod; 31. Driving gear; 32. Driven gear; 33. Stirring rod; 34. Stirring blade a; 35. Stirring blade b; 36. Hollow cylindrical bottom pipe; 37. Hydraulic rod; 38. Disc; 39. Motor b; 40. Barrel-shaped wheel; 41. Arc-shaped chute; 42. Box body; 43. Columnar slider; 44. Right groove; 45. Spring; 46. Magnet; 47. Round cake pressing block; 48. Cuboid-shaped slider; 49. Left groove; 50. Precipitation chamber; 51. Filtrate chamber. Detailed implementation manners

[0039] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Apparently, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without making creative efforts shall fall within the protection scope of the present invention.

[0040] Refer toFigure 1-8 A high-precision treatment and resource utilization system for fluorine-containing wastewater, comprising an adsorption-separation-regeneration-recycling system 1 and a PLC automatic control system 2. One end of the adsorption-separation-regeneration-recycling system 1 is provided with a base 3. One side of the upper surface of the base 3 is equipped with an adsorption device 5. One end of the adsorption device 5 is provided with a water inlet 4, and one end of the adsorption device 5 is provided with a water outlet 10. The upper end of the adsorption device 5 is installed with a separation recovery-recycling device 6. One end of the separation recovery-recycling device 6 is installed with a servo motor 11. The upper end of the servo motor 11 is provided with a rotating shaft 13. The lower end of the separation recovery-recycling device 6 is provided with a square rotating plate 14. The surface of the square rotating plate 14 is provided with a through circular opening corresponding to the round hole 16. The upper surface of the square rotating plate 14 is installed with a number of separation recovery devices 15 corresponding to the through circular opening. One end of the square rotating plate 14 is provided with a semi-circular hole. One side of the semi-circular hole is welded to the outer surface of the rotating shaft 13. One side of the square rotating plate 14 is provided with a triangular support 12 corresponding to the rotating shaft 13. The triangular support 12 is connected to the rotating shaft 13. The upper surface of the base 3 is provided with a regeneration device 7. One end of the regeneration device 7 is provided with a filtering device 8. One end of the upper surface of the base 3 is provided with a sediment collection tank 9. Through the above design, by using magnetic adsorption materials and an optimized adsorption-separation-regeneration-recycling system, an efficient defluorination effect can be achieved, reducing the fluoride ion concentration in the wastewater to below 1 mg / L. It not only solves the efficiency problem of traditional methods in treating low-concentration fluorine-containing wastewater but also ensures that the wastewater meets strict discharge standards.

[0041] Refer to Figure 2-4 Inside the adsorption device 5, there is a cylindrical adsorption tank. Eight round holes 16 are opened at the upper end of the adsorption device 5. Inside the adsorption tank, there is a baffle 23. On both sides of the adsorption tank, there are a primary adsorption tank 24 and a secondary adsorption tank 25 respectively. The baffle 23 is arranged in the middle of the primary adsorption tank 24 and the secondary adsorption tank 25. Two stirring devices 26 are installed inside the primary adsorption tank 24 and the secondary adsorption tank 25. The stirring device 26 adopts a mechanical stirring form, which can improve the contact efficiency between the magnetic adsorption material and fluoride ions in the wastewater, prevent the adsorption material from settling or aggregating, and ensure its uniform distribution.

[0042] Refer to Figure 4, one end of the stirring device 26 is installed with a motor a29, one end of the motor a29 is provided with a rotating rod 30, both sides of one end of the rotating rod 30 are provided with stirring rods 33, the outer surface of the stirring rods 33 is provided with three stirring blades a34, the inclination angle between the stirring blades a34 is set to 120°, the outer surface of the rotating rod 30 is provided with a driving gear 31, the outer surface of one of the stirring rods 33 is provided with a driven gear 32 corresponding to the driving gear 31, the driving gear 31 is engaged with the driven gear 32, the outer surface of the bottom end of the rotating rod 30 is provided with three stirring blades b35. After the motor a29 is powered on, the rotating rod 30 drives the stirring rods 33, the driving gear 31 and the stirring blades a34 to rotate horizontally around the rotating rod 30, the driving gear 31 then drives the driven gear 32, and the driven gear 32 drives the stirring blades a34 to rotate around the stirring rods 33 self - rotatably, so that the stirring blades can not only rotate horizontally, but also rotate vertically, which can make the adsorption material fully dispersed in the adsorption tank.

[0043] Refer to Figure 2-4 , the inside of the regeneration device 7 is provided with an adsorption tank same as that of the adsorption device 5. There are eight round holes 16 opened at the top of the regeneration device 7. The stirring device 26 is installed on the inner wall of the upper end of the regeneration device 7. The flushing device 27 is installed inside the regeneration device 7. There are four nozzle spray heads inside the flushing device 27. The nozzle spray heads are arranged at the lower end of the round holes 16, and the nozzles are at an angle of 60° towards the round holes 16. The reagent adding device a17 and the reagent adding device b18 are respectively installed on both sides of the upper end of the regeneration device 7. By spraying deionized water to wash the regeneration reagent remaining on the surface of the magnetic adsorption material, the reagent adding device a17 adds the regeneration reagent to desorb the magnetic adsorption material adsorbed with fluoride ions, so that the fluoride ions are transferred to the solution without changing the surface chemical properties of the magnetic material. The reagent adding device b18 adds the concentration reagent, and separates the fluoride ions in the regeneration solution through precipitation, and then finally recovers the fluoride ion precipitate into the precipitation collection box 9 through the filtering device 8 to realize resource utilization.

[0044] Refer to Figure 2 - Figure 3 and Figure 5 - Figure 7, a disk 38 is arranged inside the separation and recovery device 15. A motor b39 is installed on one side of the upper surface of the disk 38. A barrel-shaped wheel 40 is arranged at the upper end of the motor b39. An arc-shaped chute 41 is formed on the outer surface of the barrel-shaped wheel 40. A columnar slider 43 is slidably connected inside the arc-shaped chute 41. A box body 42 corresponding to the motor b39 is arranged on one side of the upper surface of the disk 38. A right-side groove 44 is formed on one side surface of the box body 42. The columnar slider 43 is slidably connected inside the right-side groove 44. A round hole 16 is formed in the middle of the disk 38. A hollow cylindrical bottom pipe 36 corresponding to the round hole 16 is arranged on the lower surface of the disk 38. Four hydraulic rods 37 are installed on the four sides of the lower surface of the disk 38. Under the action of the motor b39, the barrel-shaped wheel 40 can be driven to rotate, so that one end of the columnar slider 43 slides inside the arc-shaped chute 41, and then the columnar slider 43 can be driven to move inside the right-side groove 44.

[0045] Refer to Figure 6-7 , a spring 45 is installed inside the box body 42. A magnet 46 is arranged inside the spring 45. A round cake pressing block 47 is arranged at the upper end of the magnet 46. Cuboid-shaped sliders 48 are arranged on both sides of the round cake pressing block 47. A columnar slider 43 is arranged on the surface of one cuboid-shaped slider 48. A left-side groove 49 corresponding to the cuboid-shaped slider 48 is formed on the other side surface of the box body 42. After the motor b39 is powered on, the barrel-shaped wheel 40 is driven to rotate, and the columnar slider 43 lapped inside the arc-shaped chute 41 on the barrel-shaped wheel 40 slides downward accordingly. The columnar slider 43 drives the spring 45 and the magnet 46 to move downward, and the magnet 46 is pushed into the inside of the hollow cylindrical bottom pipe 36 through the round hole 16. Subsequently, the hydraulic rods 37 contract, so that the hollow cylindrical bottom pipe structure with the magnet drops and is pushed into the adsorption device 5 or the regeneration device 7.

[0046] Refer to Figure 6-7 , the magnet 46 is made of neodymium iron boron magnet N52, which has good magnetism and can provide a strong magnetic field support. At the same time, it has good wear resistance and scratch resistance, which prolongs its service life.

[0047] Refer to Figure 2-3 and Figure 8, a sedimentation bin 50 is provided at the lower end inside the filtering device 8, a filtrate bin 51 is provided at the upper end inside the filtering device 8, a filter screen 28 is arranged between the sedimentation bin 50 and the filtrate bin 51, a sludge suction pipe 19 is arranged at one end of the filtering device 8, the sludge suction pipe 19 is communicated with the regeneration device 7, a sediment discharge pipe 22 is arranged at one end of the filtering device 8, the sediment discharge pipe 22 is communicated with the sediment collection box 9, a reflux pipe 21 is arranged at the upper end of the filtering device 8, the other end of the reflux pipe 21 is communicated with the regeneration device 7, a pump 20 is installed at one end of the reflux pipe 21, under the action of the pump 20, the sediment in the regeneration device 7 is pumped into the interior of the sedimentation bin 50, the liquid filtered by the filter screen 28 flows into the interior of the filtrate bin 51, and then flows back to the regeneration device 7 through the reflux pipe 21, and the CaF2 sediment in the sedimentation bin 50 enters the sediment collection box 9 through the sediment discharge pipe 22 for storage.

[0048] Refer to Figure 1-8 , the PLC automatic control system 2 respectively sets fluoride ion sensors at the water inlet 4, the water outlet 10 of the adsorption device 5 and the regeneration device 7, and also sets a conductivity sensor in the regeneration device 7. By real-time monitoring of key parameters such as the F - concentration and the ionic strength of the NaCl regenerant, etc., the full-automatic control of adsorption, regeneration, sedimentation and discharge is realized, ensuring the efficient and stable operation of the defluorination system.

[0049] The implementation principle of the embodiment of the high-precision treatment and resource utilization system for fluoride-containing wastewater of the present invention is as follows:

[0050] When the system is started, the PLC controls the water inlet to open, so that the fluoride-containing wastewater after pretreatment enters the adsorption device 5 from the water inlet, first flows through the primary adsorption tank 24, and fully contacts with the magnetic adsorption material in the primary adsorption tank under the action of the stirring device 26. Under the action of physical or chemical adsorption, the fluoride-containing wastewater combines with a large number of cavities and active sites on the surface of the magnetic adsorption material, and the preliminary adsorption of the fluoride-containing wastewater is completed in the primary adsorption tank. Then, it enters the secondary adsorption tank 25 through the baffle 23, and fully contacts with the magnetic adsorption material in the secondary adsorption tank under the action of the stirring device 26, and further thoroughly adsorbs F in the wastewater in the secondary adsorption tank - . This hierarchical adsorption method can achieve gradient adsorption, improve the adsorption efficiency, prevent the saturation phenomenon of the magnetic adsorption material caused by over-adsorption of F in the two-stage adsorption tanks, extend the service life of the magnetic adsorption material, and thus improve the effect of the entire adsorption device in removing fluoride ions. Wait for the F to be detected at the water outlet - over-adsorption leads to saturation of the magnetic adsorption material, extend the service life of the magnetic adsorption material, and thus improve the effect of the entire adsorption device in removing fluoride ions. Wait for the F to be detected at the water outlet -After the concentration meets the standard, the PLC controls the adsorption device to stop operating and discharge the qualified water quality. If the fluoride ion concentration is continuously monitored at the outlet to exceed the set qualified value and maintain for 30 minutes, it is determined that the magnetic adsorption material has reached saturation. At this time, the PLC system controls the inlet and the adsorption device to close, and starts the separation and recovery device 15. The barrel-shaped wheel 40 on the square plate rotates with the motor b39, driving the cylindrical slider 43 and the cuboid slider 48 to move downward. The round cake pressing block 47 compresses the spring 45, driving the magnet 46 to move downward through the central hole of the disc 38, and pushing the magnet 46 into the hollow cylindrical bottom tube 36. Subsequently, the hydraulic rod 37 contracts, causing the hollow cylindrical bottom tube structure with the magnet to descend and be pushed into the adsorption device 5. The magnetic adsorption material will be completely attracted to the surface of the hollow cylindrical bottom tube 36 by the magnet attraction. Subsequently, the hydraulic rod 37 rises, driving the separation and recovery device 15 to recover the magnetic adsorption material from the adsorption device. Start the servo motor 11 in the separation recovery - recycling device 6, driving the square plate to rotate 14 to above the regeneration device 7. The round hole on the square plate corresponds to the round hole on the surface of the regeneration device. The hydraulic rod 37 contracts to push the hollow cylindrical bottom tube with the magnet and the magnetic adsorption material on its surface into the regeneration device 7 together. Subsequently, the barrel-shaped wheel 40 rotates in the reverse direction with the motor b39, completely pulling the magnet 46 out of the hollow cylindrical bottom tube 36. The magnetic adsorption material that has lost the magnetic attraction drops into the regeneration device 7 accordingly. Subsequently, the hydraulic rod 37 rises, driving the hollow cylindrical bottom tube 36 to return to its original position. Start the dosing device a17 and the stirring device 26 in the regeneration device 7, add the NaCl regenerant, and start the regeneration process. During this period, if the conductivity reaches the upper limit value of 5.8~23 S·m -1 , stop dosing. If the conductivity is lower than 5.8 S·m -1 during the regeneration process, the PLC system will judge that the concentration of the NaCl reagent is insufficient and automatically start the dosing device a17 to dose until the conductivity reaches the preset range, which can ensure sufficient regenerant and more thorough desorption of the magnetic adsorption material. As the regeneration process progresses, F - will desorb from the magnetic adsorption material and enter the solution, and the concentration of F - gradually increases. Wait until F -When the change range of the concentration tends to be stable over time and is less than 0.1 mg / L, the system automatically determines that the desorption is completed. After the desorption is completed, first start the separation and recovery device 15, and attract the regenerated magnetic adsorption material to the surface of the hollow cylinder bottom tube 36 through the magnetic attraction of the magnet. Then lift the hydraulic rod 37 to slowly lift the hollow cylinder bottom tube away from the regeneration liquid level, and simultaneously start the flushing device 27 to slowly flush the residual regeneration liquid on the surface of the magnetic adsorption material. Subsequently, recover the magnetic adsorption material from the regeneration pool, and then start the separation, recovery and recycling device 6. Rotate the separation, recovery and recycling device 6 above the adsorption device 5, and re-add the regenerated magnetic adsorption material to the adsorption device 5 for recycling. Subsequently, the separation and recovery device 15 returns to its original position. After multiple regeneration and recovery processes, after the magnetic adsorption material is separated from the regeneration pool, the PLC system detects the F in the regeneration pool - When the concentration reaches 40 mg / L or more, the PLC calculates the required amount of CaCl2 to be added according to the actual F in the regeneration pool - concentration, according to the molar ratio of Ca 2 + to F - of 1:2, start the dosing device b18 to add CaCl2 reagent, and react with F in the regeneration liquid - to generate CaF2 precipitate. The CaF2 precipitate passes through the sludge suction pipe 19 and is pumped into the filtration device 8 by a pump. The filtered solution passes through the filtrate bin 51 and returns to the regeneration device 7 through the return pipe 21 above the filtration device. The precipitate staying in the precipitation bin 50 is sent into the collection box 9 through the precipitation discharge pipe 22 for recycling. Regularly recycle the CaCl2 precipitate in the collection box 9, and it can be used for various industrial purposes such as a fluorinating agent in the aluminum industry, a desulfurizing agent in steel smelting, and for manufacturing fluoroplastics, etc.

[0051] In addition, the magnetic adsorption material is prepared by the coprecipitation method. Add ferric chloride hexahydrate and ferrous sulfate heptahydrate to a beaker according to the molar ratio of Fe 3+ / Fe 2+ = 2:1 and stir. Continuously introduce nitrogen into the beaker to prevent Fe 2+ from being oxidized to Fe 3+ , improve the purity of Fe3O4. Slowly add 3 - 5 mm adsorption materials such as activated alumina and hydroxyapatite to the iron salt solution, and use a magnetic stirrer to stir for 30 minutes to make the adsorption materials evenly dispersed. Use a water bath constant temperature magnetic stirrer to heat the beaker in a water bath to 60 - 80 °C and maintain constant stirring. Then slowly add 25% ammonia water or 1 - 2 mol / L sodium hydroxide solution to the beaker to adjust the pH of the iron salt solution to 9 - 11, so that Fe 3+ / Fe 2+Coprecipitation is used to form Fe3O4 magnetic nanoparticles. Observe that the solution gradually turns black. Continue stirring for 1 - 2 hours to ensure that the Fe3O4 magnetic nanoparticles are evenly coated on the surface of the adsorbent material. After the reaction ends, stop stirring and let it stand for 10 minutes to allow the magnetic adsorbent material to settle naturally. Use a vacuum filtration device to filter out the magnetic adsorbent material, and then wash it with deionized water 3 - 5 times until the pH of the washing liquid is about 7 to remove residual sodium hydroxide or ammonia. Place the washed magnetic adsorbent material in a vacuum drying oven at 60 - 80 °C for 12 h, then place it in a muffle furnace and calcine it at 300 - 400 °C for 2 h. After cooling to room temperature, discharge the product to obtain the magnetic adsorbent material.

[0052] The above embodiments are only used to illustrate the technical solutions of the present invention, not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A high-precision treatment and resource utilization system for fluorine-containing wastewater, comprising an adsorption-separation-regeneration-circulation system (1) and a PLC automatic control system (2), characterized in that: A base (3) is provided at one end of the adsorption-separation-regeneration-recycling system (1), an adsorption device (5) is installed on one side of the upper surface of the base (3), eight circular holes (16) are provided at the upper end of the adsorption device (5), a water inlet (4) is provided at one end of the adsorption device (5), a water outlet (10) is provided at one end of the adsorption device (5), a separation recovery-recycling device (6) is installed at the upper end of the adsorption device (5), a servo motor (11) is installed at one end of the separation recovery-recycling device (6), a rotating shaft (13) is provided at the upper end of the servo motor (11), and a square rotating plate (14) is provided at the lower end of the separation recovery-recycling device (6). The surface of the square rotating plate (14) is provided with a through circular opening corresponding to the circular hole (16); a plurality of separation and recovery devices (15) corresponding to the through circular opening are installed on the upper surface of the square rotating plate (14); a semicircular hole is provided at one end of the square rotating plate (14); one side of the semicircular hole is welded to the outer surface of the rotating shaft (13); a triangular bracket (12) corresponding to the rotating shaft (13) is provided on one side of the square rotating plate (14); the triangular bracket (12) is connected to the rotating shaft (13); a regeneration device (7) is provided on the upper surface of the base (3); a filtering device (8) is provided at one end of the regeneration device (7); and the upper surface of the base (3) A sedimentation collection box (9) is provided at one end, a disc (38) is provided inside the separation and recovery device (15), a motor b (39) is installed on one side of the upper surface of the disc (38), a barrel wheel (40) is provided on the upper end of the motor b (39), an arc-shaped slide groove (41) is provided on the outer surface of the barrel wheel (40), a columnar slider (43) is slidably connected inside the arc-shaped slide groove (41), a box body (42) corresponding to the motor b (39) is provided on one side of the upper surface of the disc (38), a right groove (44) is provided on one side of the surface of the box body (42), the columnar slider (43) is slidably connected inside the right groove (44), and the middle of the disc (38) The circular hole (16) is provided, the lower surface of the circular disk (38) is provided with a hollow cylindrical bottom tube (36) corresponding to the circular hole (16), hydraulic rods (37) are installed on four sides of the lower surface of the circular disk (38), a spring (45) is installed inside the box (42), a magnet (46) is provided inside the spring (45), a circular pressing block (47) is provided at the upper end of the magnet (46), rectangular sliders (48) are provided on both sides of the circular pressing block (47), the columnar slider (43) is provided on the surface of one side of the rectangular slider (48), and a left groove (49) corresponding to the rectangular slider (48) is provided on the other side surface of the box (42).

2. A high-precision treatment and resource utilization system for fluorine-containing wastewater according to claim 1, characterized in that: The adsorption device (5) is provided with a cylindrical adsorption pool inside, a baffle (23) is provided inside the adsorption pool, a primary adsorption pool (24) and a secondary adsorption pool (25) are provided on both sides of the adsorption pool, the baffle (23) is provided in the middle of the primary adsorption pool (24) and the secondary adsorption pool (25), and two stirring devices (26) are installed inside the primary adsorption pool (24) and the secondary adsorption pool (25).

3. A high-precision treatment and resource utilization system for fluorine-containing wastewater according to claim 2, characterized in that: A motor a (29) is installed at one end of the stirring device (26), a rotating rod (30) is arranged at one end of the motor a (29), stirring rods (33) are arranged on both sides of one end of the rotating rod (30), three stirring blades a (34) are arranged on the outer surface of the stirring rod (33), and the inclination angle between the stirring blades a (34) is set to 120 degrees, a driving gear (31) is arranged on the outer surface of the rotating rod (30), and a driven gear (32) corresponding to the driving gear (31) is arranged on the outer surface of one side of the stirring rod (33), and the driving gear (31) is meshed with the driven gear (32), and three stirring blades b (35) are arranged on the outer surface of the bottom end of the rotating rod (30).

4. A high-precision treatment and resource utilization system for fluorine-containing wastewater according to claim 3, characterized in that: The regeneration device (7) is provided with a cylindrical regeneration tank of the same shape as the adsorption device (5), the top of the regeneration device (7) is provided with eight circular holes (16), the inner wall of the upper end of the regeneration device (7) is provided with the stirring device (26), the regeneration device (7) is provided with a flushing device (27), the flushing device (27) is provided with four pointed nozzles, the pointed nozzles are provided at the lower ends of the circular holes (16), and the nozzles are 60 degrees toward the circular holes (16), and the dosing device a (17) and the dosing device b (18) are respectively provided on both sides of the upper end of the regeneration device (7).

5. A high-precision treatment and resource utilization system for fluorine-containing wastewater according to claim 4, characterized in that: The magnet (46) is made of neodymium iron boron magnet.

6. A high-precision treatment and resource utilization system for fluorine-containing wastewater according to claim 5, characterized in that: A sedimentation bin (50) is provided at the lower end of the filter device (8), a filtrate bin (51) is provided at the upper end of the filter device (8), a filter screen (28) is provided between the sedimentation bin (50) and the filtrate bin (51), a sludge suction pipe (19) is provided at one end of the filter device (8), the sludge suction pipe (19) is connected to the regeneration device (7), a sedimentation discharge pipe (22) is provided at one end of the filter device (8), the sedimentation discharge pipe (22) is connected to the sedimentation collection box (9), a return pipe (21) is provided at the upper end of the filter device (8), the other end of the return pipe (21) is connected to the regeneration device (7), and a pump (20) is installed at one end of the return pipe (21), the sludge suction pipe (19) and the sedimentation discharge pipe (22), respectively.

7. A high-precision treatment and resource utilization system for fluorine-containing wastewater according to claim 6, characterized in that: The PLC automatic control system (2) is provided with fluorine ion sensors at the water inlet (4), the water outlet (10) and the regeneration device (7) of the adsorption device (5), respectively, and a conductivity sensor is provided in the regeneration device (7).

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