A fluoride-containing wastewater adsorption treatment device and its fluoride-containing wastewater adsorption process

Abstract

This invention provides an adsorption treatment device and process for fluoride-containing wastewater, relating to the field of water pollution control technology. The device includes an adsorption tank, a mixing mechanism, and a feeding mechanism. The adsorption tank has a top plate fixed to its top. The mixing mechanism includes a motor mounted on the upper surface of the top plate. The motor's output shaft is keyway connected to a mixing frame. A drive pulley is keyway connected to the outer wall of the mixing frame, located below the top plate. A drain pipe is installed at the bottom of the adsorption tank. The feeding mechanism includes a fixed plate fixed to the inner wall of the adsorption tank. A driven pulley is rotatably connected to the bottom of the fixed plate. Belts are fitted onto the outer walls of the drive pulley and the driven pulley. This solution, by reducing the calcium source concentration and gelatin dosage during the adsorbent preparation stage, still achieves overall adsorbent performance highly close to normal process levels. Even when water quality conditions change due to fluctuations in fluoride concentration or acidity, the system maintains considerable pollutant adsorption capacity.

Description

Technical Field

[0001] This invention relates to the field of water pollution control, and in particular to an adsorption treatment device for fluoride-containing wastewater and its adsorption process. Background Technology

[0002] Fluoride pollution is a significant threat to global drinking water safety, especially in areas where groundwater is rich in fluoride. Long-term consumption of water with excessive fluoride concentrations can lead to dental fluorosis, osteoporosis, and even damage to the nervous system.

[0003] The industrial sector is simultaneously facing the dilemma of treating fluoride-containing wastewater. Wastewater discharged from processes such as electronic etching, rare earth smelting, and phosphate rock acid hydrolysis is characterized by strong acidity, high fluoride concentration, and complex salt base. Existing defluorination technologies generally face a contradiction between efficiency, cost, and sustainability in practical applications. Adsorption methods are considered the most promising solution due to their ease of operation.

[0004] In existing technologies, mainstream adsorption materials have systemic defects. Activated alumina fails to adsorb due to surface charge reversal in low pH environments. High-temperature regeneration increases energy consumption and costs. Inaccurate pH adjustment can affect fluoride ion removal, treatment costs, and secondary pollution control. However, there are also common problems such as unreasonable dosing methods and insufficient control precision.

[0005] Therefore, it is necessary to provide an adsorption treatment device for fluoride-containing wastewater and its adsorption process to solve the above-mentioned technical problems. Summary of the Invention

[0006] This invention provides an adsorption treatment device and process for fluoride-containing wastewater, which solves the problems of systematic defects in mainstream adsorption materials in related technologies, adsorption failure caused by surface charge reversal of activated alumina in low pH environment, increased energy consumption and cost due to high temperature regeneration mode, and poor accuracy of acid-base adjustment input.

[0007] To solve the above-mentioned technical problems, the present invention provides an adsorption treatment device for fluoride-containing wastewater, comprising an adsorption tank, a mixing mechanism, and a feeding mechanism;

[0008] The top of the adsorption tank is fixedly provided with a top plate, the mixing mechanism includes a motor installed on the upper surface of the top plate, the output shaft of the motor is connected to a mixing frame via a keyway, the outer wall of the mixing frame and located below the top plate is connected to a drive pulley via a keyway, and a drain pipe is installed at the bottom of the adsorption tank;

[0009] The feeding mechanism includes a fixed plate fixed to the inner wall of the adsorption tank. A driven pulley is rotatably connected to the bottom of the fixed plate. A belt is fitted on the outer wall of the driving pulley and the driven pulley. A rotating rod is connected to the shaft of the driven pulley via a keyway. A vertical rod is fixed to the top of the fixed plate and on both sides of the rotating rod. An inner ring is fixed to the top of the vertical rod, and an outer sleeve is fixed to the outer wall of the inner ring. A first turntable is connected to the top of the rotating rod via a keyway. Two first storage cylinders are fixed inside the first turntable. A second storage cylinder is set on the top of the two first storage cylinders. A second turntable is fixed to the top of the two second storage cylinders. A mounting seat is fixed to the outer wall of each of the two first storage cylinders. A sealing plate is rotatably mounted inside the mounting seat via a coil spring. An actuating plate is fixed to the side wall of the sealing plate.

[0010] Preferably, the outer wall of the mixing frame is rotatably connected to the top plate via bearings, and the rotating rod is rotatably connected to the fixed plate via bearings.

[0011] Preferably, the rotating rod passes through the inner ring without contacting the inner ring, and the inner walls of the two first storage cylinders and the outer walls of the two second storage cylinders are in contact with each other.

[0012] Preferably, the bottom surface of the outer cover has a concave structure, and the touch plate extends to the bottom surface of the outer cover and fits against the bottom surface of the outer cover.

[0013] Preferably, a rotating shaft is rotatably connected to the bottom of the top plate and at the same axis as the second turntable. A sleeve is fixedly provided at the top of the second turntable. A positioning bolt is threaded inside the sleeve. The sleeve is slidably connected with the rotating shaft in the vertical direction. The positioning bolt extends to the outer wall of the rotating shaft.

[0014] Preferably, it also includes auxiliary mechanisms;

[0015] The auxiliary mechanism includes a positioning plate fixed to the inner wall of the adsorption tank, a detection hole inside the positioning plate, a limiting plate fixed to the bottom of the positioning plate, a rotating rod rotatably connected inside the limiting plate, a second gear and a ratchet respectively connected to the upper and lower ends of the rotating rod via keyways, a ratchet sleeve rotatably connected inside the positioning plate and on one side of the limiting plate, a defoaming plate connected to the bottom keyway of the ratchet sleeve, and a first gear fixed to the outer wall of the second turntable.

[0016] Preferably, the first gear and the second gear are adapted to each other, and the ratchet and the ratchet sleeve mesh with each other.

[0017] Preferably, the top of the defoaming plate is rotatably connected to the positioning plate via a bearing, and the second gear shaft is positioned at a 45-degree angle to the horizontal direction of the first gear.

[0018] The fluoride-containing wastewater adsorption process includes the following steps:

[0019] S1: The lithium extraction waste residue from spodumene is mechanically crushed and then put into a reaction vessel for stirring and acid leaching. After the reaction, it is filtered and washed, and the resulting solid is dried to obtain an activated lithium slag carrier.

[0020] S2: Activated lithium slag is pre-adsorbed with calcium ions and then transferred to a dynamic reaction system to construct a three-dimensional interpenetrating network framework.

[0021] S3: The composite wet gel is transferred to a precision programmable oven for multi-stage curing;

[0022] S4: The solidified product is mechanically crushed and sieved and then piled into the adsorption column. The fluoride-containing wastewater is pre-adjusted for pH and then treated by adsorption. The concentration of the effluent is monitored in real time by an online fluoride ion electrode. The adsorption process needs to be carried out in the fluoride-containing wastewater adsorption treatment equipment. The feeding mechanism is used to add auxiliary materials to adjust the pH, and the auxiliary mechanism is used to assist in the online fluoride ion detection.

[0023] S5: After adsorption saturation, start the countercurrent backwashing program to impact the bed. During the regeneration stage, pump in the composite regeneration solution, then use deionized water for forward washing, and finally purge with dilute hydrochloric acid solution to restore the adsorbent to its initial active state.

[0024] Compared with related technologies, the fluoride-containing wastewater adsorption treatment equipment and its fluoride-containing wastewater adsorption process provided by the present invention have the following beneficial effects:

[0025] The feeding mechanism can precisely control the pH value of the wastewater after each rotation. By adding acid and alkali regulators in a quantitative manner, the pH value of the wastewater can be stably controlled within the optimal range of the adsorption reaction. This avoids problems such as the adsorption sites being occupied and the adsorbent activity decreasing due to excessively high or low pH, resulting in higher fluoride ion removal efficiency, more stable effluent quality, and ensuring that the fluoride content of the effluent continuously meets the standards.

[0026] When the calcium source concentration and gelatin dosage are reduced during the adsorbent preparation stage, the overall performance of the resulting adsorbent can still be very close to the normal process level. When water quality conditions change, such as fluctuations in fluoride concentration and changes in acidity, the system still maintains a considerable pollutant adsorption capacity. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0028] Figure 1 The optimal structural schematic diagram provided for this invention;

[0029] Figure 2 forFigure 1 The diagram shows the overall structure of the processing tank.

[0030] Figure 3 for Figure 1 The diagram shows the structure of the hybrid mechanism.

[0031] Figure 4 for Figure 1 The diagram shows a cross-sectional view of the feeding mechanism.

[0032] Figure 5 for Figure 4 The enlarged structural diagram at point A is shown below;

[0033] Figure 6 for Figure 4 The diagram shown illustrates how the second turntable drives the second storage cylinder to descend within the first storage cylinder to adjust the working state.

[0034] Figure 7 This is a detailed connection diagram of the sleeve and fixing plate shown in this invention;

[0035] Figure 8 This is a detailed structural diagram of the auxiliary mechanism shown in this invention;

[0036] Figure 9 for Figure 8 The diagram shows the working state of the first gear descending and the second gear meshing, driving the auxiliary mechanism to rotate.

[0037] Figure 10 This is a schematic diagram of the fluoride-containing wastewater adsorption process provided by the present invention.

[0038] Explanation of icon numbers:

[0039] 1. Adsorption tank;

[0040] 2. Top slab;

[0041] 3. Mixing mechanism; 31. Motor; 32. Mixing frame; 33. Drive pulley;

[0042] 4. Feeding mechanism; 41. Fixed plate; 42. Driven pulley; 43. Belt; 44. Rotating rod; 45. Vertical rod; 46. Inner ring; 47. Outer ring; 48. First turntable; 49. First storage cylinder; 410. Second storage cylinder; 411. Second turntable;

[0043] 412. Rotating shaft; 413. Sleeve; 414. Positioning bolt; 415. Mounting base; 416. Sealing plate; 417. Touch plate;

[0044] 5. Auxiliary mechanism; 51. Positioning plate; 52. Detection hole; 53. First gear; 54. Limiting plate; 55. Rotating rod; 56. Second gear; 57. Ratchet; 58. Ratchet sleeve; 59. Defoaming plate.

[0045] 6. Drain pipe. Detailed Implementation

[0046] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0047] This invention provides an adsorption treatment device for fluoride-containing wastewater and its adsorption process for fluoride-containing wastewater.

[0048] First embodiment:

[0049] Please see Figures 1 to 5 and Figure 7 A fluoride-containing wastewater adsorption treatment device includes an adsorption tank 1, a mixing mechanism 3 and a feeding mechanism 4;

[0050] The top of the adsorption tank 1 is fixedly provided with a top plate 2. The mixing mechanism 3 includes a motor 31 installed on the upper surface of the top plate 2. The output shaft of the motor 31 is connected to a mixing frame 32 via a keyway. The outer wall of the mixing frame 32 and located below the top plate 2 is connected to a drive pulley 33 via a keyway. A drain pipe 6 is installed at the bottom of the adsorption tank 1.

[0051] The feeding mechanism 4 includes a fixed plate 41 fixed to the inner wall of the adsorption tank 1. A driven pulley 42 is rotatably connected to the bottom of the fixed plate 41. A belt 43 is sleeved on the outer wall of the driving pulley 33 and the driven pulley 42. A rotating rod 44 is connected to the shaft of the driven pulley 42 via a keyway. A vertical rod 45 is fixed to the top of the fixed plate 41 and on both sides of the rotating rod 44. An inner ring 46 is fixed to the top of the vertical rod 45. An outer sleeve 47 is fixed to the outer wall of the inner ring 46. A first turntable 48 is connected to the top of the rotating rod 44 via a keyway. Two first storage cylinders 49 are fixed inside the first turntable 48. A second storage cylinder 410 is provided on the top of the two first storage cylinders 49. A second turntable 411 is fixed to the top of the two second storage cylinders 410. A mounting seat 415 is fixed to the outer wall of each of the two first storage cylinders 49. A sealing plate 416 is rotatably installed inside the mounting seat 415 via a coil spring. A touch plate 417 is fixed to the side wall of the sealing plate 416.

[0052] The outer wall of the mixing frame 32 is rotatably connected to the top plate 2 via bearings, and the rotating rod 44 is rotatably connected to the fixed plate 41 via bearings.

[0053] The rotating rod 44 passes through the inner ring 46 but does not contact the inner ring 46. The inner walls of the two first storage cylinders 49 and the outer walls of the two second storage cylinders 410 are in contact with each other.

[0054] The bottom surface of the outer casing 47 is concave, and the touch plate 417 extends to the bottom surface of the outer casing 47 and fits against the bottom surface of the outer casing 47.

[0055] Please see Figure 3 and Figure 4 When adjusting the pH, the user can install an acid or alkali feed pipe on the top of the second storage cylinder 410 on the right side, which is attached to the top of the second storage cylinder 410. The acid or alkali can be transported into the second storage cylinder 410 through the feed pipe. Since the second storage cylinder 410 and the first storage cylinder 49 are designed to be connected, both the first storage cylinder 49 and the second storage cylinder 410 will be filled with acid or alkali regulator.

[0056] During adsorption, the pH of the fluoride-containing wastewater needs to be adjusted first. The fluoride-containing wastewater enters the adsorption tank 1 from the top. The user starts the motor 31 to drive the mixing rack 32 to rotate. When the mixing rack 32 rotates, it fully mixes the fluoride-containing wastewater and the acid and alkali agents. After mixing, it is adsorbed through the adsorption column in the adsorption tank 1.

[0057] The adsorption column is constructed by multi-stage curing of composite wet gel. When the mixing frame 32 rotates, it simultaneously drives the drive pulley 33 and the transmission belt 43 to control the rotation of the driven pulley 42.

[0058] Please participate Figure 4 and Figure 5 When the driven pulley 42 rotates, it drives the rotating rod 44 to control the rotation of the first turntable 48. When the first turntable 48 rotates, it drives the two first storage cylinders 49 to rotate and controls the two second storage cylinders 410 to drive the second turntable 411 to rotate.

[0059] During the rotation, the first storage cylinder 49, which is filled with acid and alkali, is rotated to the bottom recess of the outer casing 47. At this time, when the touch plate 417 rotates to the recess, it is pulled by the coil spring in the mounting base 415. The touch plate 417 enters the recess in the outer casing 47, thereby driving the sealing plate 416 to rotate along the hinge of the mounting base 415. When rotating, the bottom of the first storage cylinder 49 is opened. After opening, the acid and alkali in the second storage cylinder 410 and the first storage cylinder 49 automatically fall into the adsorption tank 1 for quantitative addition of acid and alkali.

[0060] As the first storage cylinder 49 continues to rotate, when the touch plate 417 moves away from the recess under the outer sleeve 47, the sealing plate 416 can be automatically flipped to seal the first storage cylinder 49, so that the acid and alkali agent can be refilled. Therefore, the acid and alkali agent can be added quantitatively multiple times through repeated cycles.

[0061] Understandable: combination Figure 7 As can be seen, since the fixed plate 41 and the adsorption tank 1 are fixed, the stability of the driven pulley 42 and the rotating rod 44 during rotation can be guaranteed. The outer sleeve 47 is fixed by the inner ring 46, the upright rod 45 and the fixed plate 41, so it can be guaranteed that the rotating rod 44 will not affect or interfere with the fixed outer sleeve 47 during rotation. Therefore, the rotation of the first turntable 48 will not affect the outer sleeve 47.

[0062] Please see Figure 1 and Figure 2 In one application scenario, the aforementioned fluoride-containing wastewater adsorption treatment equipment can be used to adsorb heavy metal wastewater containing chromium, nickel, copper, zinc, lead, cadmium, etc., generated by industries such as electroplating, metallurgy, and chemical processing. It can effectively adsorb and remove heavy metal ions through the adsorbent, achieving stable compliance with wastewater standards.

[0063] When adsorbing heavy metal wastewater generated by industries such as electroplating, metallurgy, and chemical industry, the heavy metal wastewater generated by these industries is injected into adsorption tank 1, and the pH is adjusted and mixed adsorption is performed as described above.

[0064] In another application, the fluoride-containing wastewater adsorption treatment equipment can also be used for the adsorption treatment of wastewater such as pesticides, fertilizers, food processing, domestic sewage, and comprehensive wastewater from industrial parks.

[0065] This embodiment:

[0066] The feeding mechanism 4 can precisely control the pH value of the wastewater after each rotation, significantly improving the adsorption and removal efficiency and stability of fluoride removal. The adsorption method for removing fluoride ions is sensitive to the pH value of the system. The adsorbent can only reach its maximum adsorption capacity within a suitable pH range. By adding acid and alkali regulators in a quantitative manner, the pH value of the wastewater can be stably controlled within the optimal range of the adsorption reaction, avoiding problems such as the occupation of adsorption sites and the decrease in adsorbent activity caused by excessively high or low pH. This results in higher fluoride ion removal efficiency, more stable effluent quality, and ensures that the fluoride content in the effluent continuously meets the standards.

[0067] Unstable acid and alkali dosage can lead to large fluctuations in wastewater pH, which not only affects the adsorption effect but also has an adverse impact on subsequent processes such as flocculation, sedimentation, and membrane treatment. By quantitatively and stably adding acid and alkali regulators, the pH of wastewater can be kept stable, avoiding the impact of drastic changes in water quality on the entire treatment system and improving the safety and continuity of process operation.

[0068] Adsorption treatment can quickly and efficiently remove fluoride ions from industrial wastewater, significantly reduce the fluoride content in external drainage, and prevent high-fluoride wastewater from being directly discharged into water bodies, causing fluoride pollution of surface water and groundwater. It cuts off the path of fluoride pollutants entering the natural water environment from the source and ensures the safety of the water environment in the basin.

[0069] When the calcium source concentration is reduced and the amount of gelatin is decreased during the adsorbent preparation stage, the overall performance of the resulting adsorbent can still be very close to the normal process level. When water quality conditions such as fluctuations in fluoride concentration and changes in acidity occur during application, the system still maintains a considerable pollutant adsorption capacity.

[0070] This indicates that the two-step synergistic mechanism of hydroxyapatite directional mineralization and gelatin network solidification has good flexibility, which can not only adapt to reasonable fluctuations in raw material ratios, but also effectively cope with the dynamic changes of complex wastewater, providing a solid technical foundation for practical engineering applications.

[0071] Second embodiment:

[0072] Please see 1 and Figure 6 The top plate 2 is rotatably connected to a rotating shaft 412 at the bottom and on the same axis as the second turntable 411. A sleeve 413 is fixed at the top of the second turntable 411. A positioning bolt 414 is threaded inside the sleeve 413. The sleeve 413 is slidably connected with the rotating shaft 412 in the vertical direction. The positioning bolt 414 extends to the outer wall of the rotating shaft 412.

[0073] Please see Figure 1 and Figure 6 In the first embodiment, during operation, the user rotates the positioning bolt 414 to loosen it, and then slides the sleeve 413 downward to cause the second turntable 411 to drive the second storage cylinder 410 to descend. When the second storage cylinder 410 descends and intersects in the first storage cylinder 49, the storage capacity in the first storage cylinder 49 and the second storage cylinder 410 can be changed, thus changing the storage amount of acid and alkali agent.

[0074] Understandably, since the rotating shaft 412 is rotatably connected to the top plate 2, the second turntable 411 can maintain stable rotation during the lifting and lowering process.

[0075] This embodiment:

[0076] This embodiment can match the optimal pH conditions in real time according to the wastewater quality, which can greatly improve the fluoride ion adsorption and removal effect. It can not only realize the quantitative addition of acid and alkali adjusters, but also flexibly adjust the acid and alkali dosage according to the influent concentration, water quality, temperature and adsorbent reaction requirements of fluoride-containing wastewater, so as to accurately stabilize the pH of the system in the optimal range for fluoride adsorption and removal, maximize the adsorption capacity of the adsorbent, ensure high and stable fluoride ion removal efficiency, and ensure that the effluent continuously meets the standards.

[0077] Adjustable quantitative addition allows for the addition of acid-base regulators as needed. Less is added when the water quality is good, and the amount is increased appropriately when the water quality is poor. While ensuring the treatment effect, it avoids problems such as waste of reagents, increased salinity, and increased sludge caused by excessive addition, thereby reducing reagent consumption and hazardous waste disposal costs and improving the economic efficiency of wastewater treatment.

[0078] Third embodiment:

[0079] Please see Figures 8 to 9 It also includes auxiliary mechanism 5;

[0080] The auxiliary mechanism 5 includes a positioning plate 51 fixed to the inner wall of the adsorption tank 1. The positioning plate 51 has a detection hole 52 inside. A limiting plate 54 is fixed to the bottom of the positioning plate 51. A rotating rod 55 is rotatably connected inside the limiting plate 54. The upper and lower ends of the rotating rod 55 are respectively keyway connected to a second gear 56 and a ratchet 57. A ratchet sleeve 58 is rotatably connected inside the positioning plate 51 and located on one side of the limiting plate 54. A defoaming plate 59 is connected to the bottom keyway of the ratchet sleeve 58. A first gear 53 is fixed to the outer wall of the second turntable 411.

[0081] The first gear 53 and the second gear 56 are adapted to each other, and the ratchet 57 and the ratchet sleeve 58 mesh with each other.

[0082] The top of the defoaming plate 59 is rotatably connected to the positioning plate 51 via a bearing, and the axis of the second gear 56 is set at a 45-degree angle to the horizontal direction of the first gear 53.

[0083] Please see Figure 8 During the operation of the first embodiment, the first gear 53 and the second gear 56 outside the second turntable 411 are in a separated state, so the second turntable 411 does not control the auxiliary mechanism 5 to work when it rotates.

[0084] Please see Figure 9 In the second embodiment, when the second turntable 411 descends, it drives the first gear 53 to descend and the second gear 56 to engage. At this time, when the second turntable 411 rotates, it can drive the first gear 53 to engage and control the rotation of the second gear 56.

[0085] When the second turntable 411 drives the first gear 53 to rotate counterclockwise, the first gear 53 meshes with the second gear 56 to rotate clockwise, thereby controlling the rotating rod 55 to drive the ratchet 57 to rotate clockwise, affecting the ratchet sleeve 58 to control the defoaming plate 59 at the bottom to rotate on the liquid surface of the adsorption tank 1 for defoaming treatment. The user inserts the online fluoride ion detector into the adsorption tank 1 through the detection hole 52 to detect fluoride ions.

[0086] When the second turntable 411 drives the first gear 53 to rotate clockwise, the second gear 56 will mesh and rotate counterclockwise. When rotating counterclockwise, the ratchet 57 will not drive the ratchet sleeve 58 to control the defoaming plate 59 to rotate. Therefore, the mixing and feeding work in the first embodiment can still be maintained, and the defoaming function will not be activated.

[0087] This embodiment:

[0088] Auxiliary mechanism 5 can eliminate the interference of foam on fluoride ion detection, improve detection accuracy, and ensure the scientific nature of quantitative adjustment. In the adsorption treatment of fluoride-containing wastewater, foam is easily generated when acid-base regulators are added quantitatively. Foam can encapsulate fluoride ions and adsorbent particles or adhere to the surface of the detection probe, causing deviations in fluoride ion detection results and affecting the accuracy of acid-base dosage adjustment. In this embodiment, foam can be automatically and synchronously defoamed while adjusting the dosage, which can quickly break up the foam in the system, avoid the foam from blocking or interfering with the detection signal, ensure the authenticity and accuracy of fluoride ion detection data, provide reliable data support for quantitative acid-base adjustment, make the dosage adjustment more in line with the actual water quality requirements of wastewater, and further improve the stability of adsorption and fluoride removal effect.

[0089] The fluoride-containing wastewater adsorption process includes the following steps:

[0090] S1: The lithium extraction waste residue from spodumene is mechanically crushed to a particle size of 100-150 mesh and put into a corrosion-resistant reactor. A sulfuric acid solution of 1-3 mol / L concentration is added at a solid-liquid mass ratio of 1:1-1:5. After sealing, the stirring device is started and a constant speed of 100-300 rpm is maintained.

[0091] The reaction temperature is 50~80°C, and the reaction time is 1~3 hours. Under these mild acid etching conditions, the Al in the aluminum-oxygen tetrahedral network is selectively fractured. - O - Si chemical bonds are fully preserved, ≡Al - OH active sites were identified, and the residual fluoride dissolution rate was suppressed to less than 0.1%. At the end of the reaction, the slurry was filtered and washed with deionized water until the pH of the filtrate stabilized in the range of 6 to 6.5. The resulting solid was transferred to a constant temperature drying oven and dried at 60°C for 2 hours. Finally, an activated lithium slag carrier with a well-developed mesoporous structure was obtained.

[0092] S2: Activated lithium slag is uniformly dispersed in a 0.2–0.5 mol / L calcium chloride solution. Sodium citrate crystal regulator, accounting for 3%–5% of the total calcium ions, is added. The system is heated to 40℃ for calcium ion pre-adsorption for 30 min, and then transferred to a dynamic reaction system. It is mixed with a 0.1–0.5 mol / L disodium hydrogen phosphate solution, and the pH is adjusted to 8.5–9 with a trace amount of ammonia. Simultaneously, a 5%–10% gelatin solution preheated to 50℃ is injected. The mixture is emulsified in a constant temperature water bath at 60.0℃ and reacted for 2 h. Sodium citrate selectively adsorbs onto the hydroxyapatite crystal face, inhibiting lateral growth and forming needle-like structures with an aspect ratio of 10:1–20:1 and a crystal length of 200–300 nm. Simultaneously, the gelatin peptide chains chelate with calcium ions to construct a three-dimensional interpenetrating network framework.

[0093] S3: The composite wet gel was transferred to a precision programmable oven for multi-stage curing. The first stage involved curing at 50°C in a static environment for 1 hour, inducing the gelatin molecules to undergo β-fold lamellar self-assembly, forming a primary network with a thickness of approximately 10-15 nm. The second stage involved heating to 65°C, triggering the formation of ≡Al from aluminum hydroxyl groups and hydroxyapatite calcium ions on the lithium slag surface. - O - Ca chemical bonds, heat preservation and curing at this temperature for 1 hour, drying under vacuum for 4 hours, to obtain regular particulate products with a moisture content ≤2% and a compressive strength of 18MPa;

[0094] S4: The solidified product is mechanically crushed and sieved into uniform particles of 1.0-3.0 mm. The bulk density is filled into a fixed bed adsorption column with a column diameter to height ratio of 1:5-1:10. The pH of the fluoride-containing wastewater is pre-adjusted to 4-10. The column is treated by a constant flow pump at an empty tower flow rate of 10-15 BV / h. The process temperature is kept constant at 25℃. The effluent concentration is monitored in real time by an online fluoride ion electrode. The breakthrough endpoint is set at a fluoride ion concentration ≥1.5 mg / L. Under these conditions, the measured breakthrough adsorption capacity reaches 20-25 mg / g.

[0095] The adsorption process needs to be carried out in the fluoride-containing wastewater adsorption treatment equipment as described in any one of claims 1-8, wherein the feeding mechanism 4 is used to add auxiliary materials to adjust the pH, and the auxiliary mechanism 5 is used to assist in online fluoride ion detection;

[0096] S5: After adsorption saturation, the countercurrent backwashing program is started, and the bed is impacted with a high-speed water flow of 30 BV / h for 10 min to effectively remove the trapped suspended solids. During the regeneration stage, a composite regeneration solution containing 4% sodium hydroxide, 3% sodium chloride and 0.5% sodium citrate is pumped in and circulated through the adsorption bed at a slow flow rate of 1~5 BV / h for 1 h under controlled temperature of 60℃. Citrate ions and calcium fluoride form a water-soluble complex, which synergistically rebuilds the active lattice of hydroxyapatite with hydroxide ions. Then, deionized water is used for forward washing until the pH of the effluent stabilizes at 7.0±0.5. Finally, 0.1% dilute hydrochloric acid solution is introduced for transformation treatment for 10 min to restore the adsorbent to its initial active state.

[0097] Please refer to the reference again. Figures 1 to 10 The working principle of the fluoride-containing wastewater adsorption treatment equipment and its fluoride-containing wastewater adsorption process provided by the present invention is as follows:

[0098] Step S1: pH adjustment;

[0099] Fluorine-containing wastewater enters adsorption tank 1 from the top. The user starts motor 31, which drives mixing frame 32 to rotate. As mixing frame 32 rotates, it thoroughly mixes the fluorine-containing wastewater and acid / alkali agents. The mixed wastewater is then adsorbed through adsorption columns within adsorption tank 1. These columns are constructed from composite wet gel after multi-stage curing. Simultaneously, the rotation of mixing frame 32 drives drive pulley 33 and transmission belt 43, which in turn drives driven pulley 42. The rotation of driven pulley 42 drives rotating rod 44, which in turn drives first turntable 48. The rotation of first turntable 48 drives two first storage cylinders 49 to rotate, controlling the rotation of the two storage cylinders. The second storage cylinder 410 drives the second turntable 411 to rotate. During the rotation, the first storage cylinder 49, which is filled with acid and alkali, is rotated to the bottom recess of the outer casing 47. At this time, when the touch plate 417 rotates to the recess, it is pulled by the coil spring in the mounting base 415. The touch plate 417 enters the recess in the outer casing 47, thereby driving the sealing plate 416 to flip along the hinge of the mounting base 415. When flipping, the bottom of the first storage cylinder 49 is opened. After opening, the acid and alkali in the second storage cylinder 410 and the first storage cylinder 49 automatically fall into the adsorption tank 1 for quantitative addition of acid and alkali.

[0100] Step S2: The composite wet gel is transferred to a precision programmable oven for multi-stage curing. The cured product is mechanically crushed and sieved into uniform particles, which are then packed into a fixed-bed adsorption column with a column diameter to height ratio of 1:5 to 1:10. The pH of the fluoride-containing wastewater is pre-adjusted to 4 to 10. The column is then treated using a constant flow pump at a flow rate of 10 to 15 BV / h in the empty column. The process temperature is kept constant at 25°C. The effluent concentration is monitored in real time using an online fluoride ion electrode. The breakthrough endpoint is set at a fluoride ion concentration ≥ 1.5 mg / L. Under these conditions, the measured breakthrough adsorption capacity reaches 20 to 25 mg / g, thus completing the adsorption.

[0101] The above description is only a preferred embodiment of the present invention and does not limit the patent scope of the present invention. All equivalent structural transformations made under the concept of the present invention using the contents of the present invention specification and drawings, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A fluoride-containing wastewater adsorption treatment device, characterized in that, Includes an adsorption tank, a mixing mechanism, and a feeding mechanism; The top of the adsorption tank is fixedly provided with a top plate, the mixing mechanism includes a motor installed on the upper surface of the top plate, the output shaft of the motor is connected to a mixing frame via a keyway, the outer wall of the mixing frame and located below the top plate is connected to a drive pulley via a keyway, and a drain pipe is installed at the bottom of the adsorption tank; The feeding mechanism includes a fixed plate fixed to the inner wall of the adsorption tank. A driven pulley is rotatably connected to the bottom of the fixed plate. A belt is fitted on the outer wall of the driving pulley and the driven pulley. A rotating rod is connected to the shaft of the driven pulley via a keyway. A vertical rod is fixed to the top of the fixed plate and on both sides of the rotating rod. An inner ring is fixed to the top of the vertical rod, and an outer sleeve is fixed to the outer wall of the inner ring. A first turntable is connected to the top of the rotating rod via a keyway. Two first storage cylinders are fixed inside the first turntable. A second storage cylinder is set on the top of the two first storage cylinders. A second turntable is fixed to the top of the two second storage cylinders. A mounting seat is fixed to the outer wall of each of the two first storage cylinders. A sealing plate is rotatably mounted inside the mounting seat via a coil spring. An actuating plate is fixed to the side wall of the sealing plate.

2. The fluoride-containing wastewater adsorption treatment equipment according to claim 1, characterized in that, The outer wall of the mixing frame is rotatably connected to the top plate via bearings, and the rotating rod is rotatably connected to the fixed plate via bearings.

3. The fluoride-containing wastewater adsorption treatment equipment according to claim 1, characterized in that, The rotating rod passes through the inner ring without contacting it, and the inner walls of the two first storage cylinders and the outer walls of the two second storage cylinders are in contact with each other.

4. The fluoride-containing wastewater adsorption treatment equipment according to claim 1, characterized in that, The bottom surface of the outer cover has a concave structure, and the touch plate extends to the bottom surface of the outer cover and fits against the bottom surface of the outer cover.

5. The fluoride-containing wastewater adsorption treatment equipment according to claim 1, characterized in that, The top plate is rotatably connected to a rotating shaft at the bottom and on the same axis as the second turntable. A sleeve is fixedly provided at the top of the second turntable. A positioning bolt is threaded inside the sleeve. The sleeve is slidably connected about the rotating shaft in a vertical direction. The positioning bolt extends to the outer wall of the rotating shaft.

6. The fluoride-containing wastewater adsorption treatment equipment according to claim 1, characterized in that, It also includes auxiliary mechanisms; The auxiliary mechanism includes a positioning plate fixed to the inner wall of the adsorption tank, a detection hole inside the positioning plate, a limiting plate fixed to the bottom of the positioning plate, a rotating rod rotatably connected inside the limiting plate, a second gear and a ratchet respectively connected to the upper and lower ends of the rotating rod via keyways, a ratchet sleeve rotatably connected inside the positioning plate and on one side of the limiting plate, a defoaming plate connected to the bottom keyway of the ratchet sleeve, and a first gear fixed to the outer wall of the second turntable.

7. The fluoride-containing wastewater adsorption treatment equipment according to claim 6, characterized in that, The first gear and the second gear are adapted to each other, and the ratchet and the ratchet sleeve mesh with each other.

8. The fluoride-containing wastewater adsorption treatment equipment according to claim 6, characterized in that, The top of the defoaming plate is rotatably connected to the positioning plate via a bearing, and the second gear shaft is set at a 45-degree angle to the horizontal direction of the first gear.

9. A fluoride-containing wastewater adsorption process, characterized in that, Includes the following steps: S1: The lithium extraction waste residue from spodumene is mechanically crushed and then put into a reaction vessel for stirring and acid leaching. After the reaction, it is filtered and washed, and the resulting solid is dried to obtain an activated lithium slag carrier. S2: Activated lithium slag is pre-adsorbed with calcium ions and then transferred to a dynamic reaction system to construct a three-dimensional interpenetrating network framework. S3: The composite wet gel is transferred to a precision programmable oven for multi-stage curing; S4: The solidified product is mechanically crushed and sieved and then piled into the adsorption column. The fluoride-containing wastewater is pre-adjusted for pH and then treated by adsorption. The concentration of the effluent is monitored in real time by an online fluoride ion electrode. The adsorption process needs to be carried out in the fluoride-containing wastewater adsorption treatment equipment as described in any one of claims 1-8. The feeding mechanism is used to add auxiliary materials to adjust the pH. The auxiliary mechanism is used to assist in online fluoride ion detection. S5: After adsorption saturation, start the countercurrent backwashing program to impact the bed. During the regeneration stage, pump in the composite regeneration solution, then use deionized water for forward washing, and finally purge with dilute hydrochloric acid solution to restore the adsorbent to its initial active state.

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