Integrated device for advanced defluorination of wastewater

Abstract

The utility model belongs to wastewater treatment technical field, specifically disclose a kind of integrated device of wastewater advanced defluorination, including array setting and sequentially communicating first-stage reaction mixing area, first-stage separation zone, second-stage reaction mixing area, second-stage separation zone, the bottom of first-stage reaction mixing area is equipped with independent equipment storehouse, first-stage reaction mixing area includes 2*2 planar arrangement and sequentially communicating first-stage reaction tank A, first-stage reaction tank B, coagulation tank, first-stage flocculator;Second-stage reaction mixing area includes array arrangement and sequentially communicating second-stage reaction tank, pH back call pool, second-stage flocculator;The first-stage reaction tank A, B, coagulation tank, second-stage reaction tank, pH back call pool are equipped with lifting type aeration internal circulation device and aeration washing device;First-stage flocculator, second-stage flocculator are equipped with aeration washing device and agitator.The utility model is integrated equipment, saves floor area;And increase lifting type aeration internal circulation device and aeration washing device, significantly improve defluorination effect.

Description

Technical Field

[0001] This utility model belongs to the field of wastewater treatment technology, and specifically relates to an integrated device for deep defluorination of wastewater. Background Technology

[0002] Fluorine is a common element in industrial wastewater, and some industries discharge wastewater with high concentrations of fluoride. If this industrial wastewater is discharged without treatment, over time, fluoride will slowly seep into the soil, surface water, and groundwater, leading to a gradual increase in the fluoride content in nature. Excessive ingestion of fluoride-contaminated water can cause serious health problems.

[0003] In recent years, some cities and river basins have implemented fluoride emission requirements comparable to drinking water standards. For example, Beijing's "Discharge Standard of Pollutants for Urban Wastewater Treatment Plants" (DB11 / 890-2012) stipulates that the fluoride emission limit has been adjusted to 1.5 mg / L, and Jiangsu Province's "Comprehensive Discharge Standard of Water Pollutants for the South Four Lakes Basin (Jiangsu Region)" (DB32 / 4576-2023) stipulates that the limit for key protection areas and general protection areas in the South Four Lakes Basin (Jiangsu Region) is 2.0 mg / L. Therefore, it is necessary to pay attention to the need for deep defluorination of fluoride-containing industrial wastewater to around 1.0 mg / L.

[0004] Currently, commonly used wastewater defluoridation processes include chemical precipitation, adsorption, ion exchange, and membrane filtration. Adsorption and ion exchange methods suffer from high treatment costs, and saturated resins require desorption before continued use. Membrane filtration can achieve deep defluoridation of wastewater, but it suffers from high overall equipment investment and operating costs, complex equipment operation and maintenance, and the need for further treatment of the concentrated filtrate produced by membrane filtration, thus limiting its application in engineering projects. Chemical precipitation is widely used in wastewater defluoridation due to its simple operation, wide applicability, and low cost. However, problems such as uneven dispersion of chemical agents like calcium fluoride in wastewater or impurity deposition result in effluent fluoride levels typically exceeding 10 mg / L, failing to meet the requirements for deep defluoridation. Furthermore, existing chemical precipitation methods generally require multiple parallel treatment zones, such as sedimentation, dosing, reaction, flocculation, and separation zones, leading to a large footprint and high operating costs. Utility Model Content

[0005] To address the shortcomings of existing technologies mentioned in the background section, the purpose of this invention is to provide an integrated device for deep defluorination of wastewater, saving floor space and thus reducing operating costs. Simultaneously, it improves the dispersion ability of chemical agents, accelerating the flocculation, precipitation, and separation of fluorides in wastewater, resulting in a fluoride content of approximately 1.0 mg / L in the effluent.

[0006] To achieve the above objectives, the technical solution of this utility model is as follows: An integrated device for deep defluorination of wastewater includes a primary reaction mixing zone, a primary separation zone, a secondary reaction mixing zone, and a secondary separation zone arranged in a row and connected in sequence. The bottom of the primary reaction mixing zone has an independent equipment compartment. The primary reaction mixing zone includes a primary reaction tank A, a primary reaction tank B, a coagulation tank, and a primary flocculation tank arranged in a 2x2 plan and connected in sequence. The secondary reaction mixing zone includes a secondary reaction tank, a pH adjustment tank, and a secondary flocculation tank arranged in a row and connected in sequence. Each of the primary reaction tank A, primary reaction tank B, coagulation tank, secondary reaction tank, and pH adjustment tank is equipped with a lift-type aeration internal circulation device and an aeration flushing device. Each of the primary and secondary flocculation tanks is equipped with an aeration flushing device and a stirrer.

[0007] In a further embodiment, the lifting aeration internal circulation device includes an inner tube and an outer tube coaxially sleeved together, with a dosing chamber formed between the inner tube and the outer tube; The top end of the inner tube extends to the outside of the pool and connects to an external air source, while the bottom end of the inner tube extends to the outside of the outer tube and connects to an aerator located at the bottom of the pool. The bottom of the outer tube is connected to an air pipe, which is used to introduce an external air source into the dosing chamber to drive water circulation.

[0008] In a further embodiment, the top end of the inner tube is fixedly connected to the top end of the pool via a fixed bracket; the bottom end of the outer tube is connected to a connecting cylinder that is flared outwards and narrower at the top than at the bottom.

[0009] Preferably, a regulating valve is installed on the air pipe; The aerator includes an aerator body and aeration branch pipes spaced apart on the outer periphery of the aerator body, and aeration holes are provided on the aeration branch pipes.

[0010] In a further embodiment, the aeration and flushing device includes a flushing pipe arranged circumferentially along the inner wall of the pool, one end of which is connected to an external air source, and a flushing hole is provided on the side of the flushing pipe facing the inner wall of the pool.

[0011] In a further embodiment, multiple flushing pipes are arranged from top to bottom, with a spacing of 0.8 to 1 m between adjacent flushing pipes; the distance between the flushing pipes and the inner wall of the pool is 8 to 15 cm. The flushing holes are opened in the horizontal, upward, and downward directions, respectively, with a diameter of 3-5 mm and a spacing of 30-50 mm between adjacent flushing holes.

[0012] In a further embodiment, the primary separation zone and the secondary separation zone have the same structure; The bottom of the primary separation zone is provided with a mud hopper, and an inclined tube packing layer is provided above the mud hopper; The inlet end of the primary separation zone is longitudinally provided with an inlet overflow trough and an inlet baffle; the top surface of the inlet overflow trough is located between the outlet of the primary flocculation tank and the liquid surface of the primary separation zone. The top of the water inlet baffle is flush with the top surface of the primary separation zone, and the bottom is located above the mud hopper.

[0013] A further embodiment includes a packing backwashing device fixed below the inclined tube packing layer for flushing the inclined tube packing layer. The distance between the water inlet overflow trough and the water inlet baffle is 20-50cm; the top surface of the water inlet overflow trough is 5-10cm higher than the liquid level in the primary separation zone. The distance between the bottom of the inlet baffle and the mud hopper is 0.5 to 0.8 m, and the bottom of the inlet baffle is bent to guide the flow.

[0014] In a further embodiment, the equipment compartment is equipped with a blower, a dosing device, and a controller. The blower is used to provide an external air source for the lifting aeration internal circulation device and the aeration flushing device. The dosing port of the dosing device is connected to the lifting aeration internal circulation device through a pipeline.

[0015] In a further embodiment, the top of the primary reaction tank A is provided with an inlet for introducing wastewater; the top of the secondary separation zone is provided with an outlet. Both the inlet and outlet are equipped with detectors for detecting fluoride; a flow meter is installed on the inlet. pH meters are installed in both the primary reaction tank A and the pH adjustment tank.

[0016] In this application, the integrated device first pumps wastewater into the primary reaction tank A, where calcium hydroxide is added to adjust the pH to 9-10. Then, it flows into the primary reaction tank B, where a primary defluorinating agent, calcium chloride, is added. The effluent then flows sequentially through a coagulation tank, a primary flocculation tank, and a primary separation zone. PAC is added to the coagulation tank, and PAM is added to the primary flocculation tank. Sludge and wastewater are then separated in the primary separation zone. The wastewater separated in the primary separation zone flows by gravity to the secondary reaction mixing zone, where a secondary defluorinating agent (modified aluminum, iron, and silicon polymer) is added. The effluent then flows to a pH adjustment tank, where a secondary pH adjuster, liquid alkali, is added to adjust the pH to 6-7. The effluent then flows through the secondary flocculation tank, where PAM is added. Finally, sludge and wastewater are separated in the secondary separation zone. The core protection of this application is the integrated device; specific dosages are not within the scope of protection and are merely for illustrative purposes.

[0017] The integrated device of this application is made of carbon steel and has an outer steel structure frame. The interior is lined with five layers of cloth and seven layers of vinyl resin for corrosion protection. Its beneficial effect is to ensure the equipment is corrosion resistant while greatly reducing equipment investment.

[0018] This utility model provides an integrated device for deep defluorination of wastewater. It is an integrated device that makes full use of three-dimensional space by placing the equipment compartment at the bottom of the primary reaction mixing zone, thus saving floor space.

[0019] This application improves the dispersion ability of chemical agents by combining a booster aeration internal circulation device and an aeration flushing device, thereby accelerating the flocculation, precipitation and separation of fluoride in wastewater, so that the fluoride content in the effluent reaches about 1.0 mg / L.

[0020] This application incorporates lift-type aeration and internal circulation devices in primary reaction tank A, primary reaction tank B, coagulation tank, secondary reaction tank, and pH adjustment tank to optimize water flow, extend reaction time, and prevent short-circuiting. Air-driven internal circulation and aeration mixing are used to promote mixing between wastewater and chemicals, eliminating the need for a mixer in this treatment system, further reducing operating costs and mechanical failures. Aeration and flushing devices are installed in each tank within the primary and secondary reaction mixing zones to optimize water flow and reduce dead zones around the edges and corners, resulting in more uniform chemical dispersion and more thorough fluoride reaction in the wastewater. These devices also serve a flushing function, preventing scale buildup on the tank walls.

[0021] This application provides an inlet overflow trough and an inlet baffle at the inlet end of the primary and secondary separation zones, respectively, to reduce the water flow velocity and extend the reaction time, thereby ensuring the stability of the hydraulic flow state entering the separation zone (sedimentation zone) and improving the sedimentation effect.

[0022] The device described in this application treats wastewater with excellent and thorough defluorination effects, and is suitable for deep defluorination and upgrading of fluoride-containing wastewater such as electronic wastewater, chemical wastewater, and industrial park wastewater. Attached Figure Description Figure 1 This is a top view of the present invention; Figure 2 yes Figure 1 AA cross-section view; Figure 3 yes Figure 1 BB cross-section; Figure 4 This is a schematic diagram of the structure of a lift-type aeration internal circulation device.

[0023] In the picture: 1. Inlet; 2. Primary Reaction Tank A; 3. Primary Reaction Tank B; 4. Coagulation Tank; 5. Primary Flocculation Tank; 6. Primary Separation Zone; 7. Secondary Reaction Tank; 8. pH Adjustment Tank; 9. Secondary Flocculation Tank; 10. Secondary Separation Zone; 11. Outlet; 12. Lift-type aeration internal circulation device; 121. Inner pipe; 122. Outer pipe; 123. Air inlet; 124. Aerator; 125. Aeration branch pipe; 126. Connecting cylinder; 127. Air inlet pipe; 128. Regulating valve; 129. Fixed bracket; 13. Aeration and flushing device; 14. First agitator; 15. Inlet overflow tank; 16. Inlet baffle; 17. Inclined tube packing layer; 18. Packing backwashing device; 19. Second agitator; 20. Blower; 21. Dosing device; 22. Controller; 23. First pH meter; 24. Second pH meter; 25. Inlet water detector; 26. Outlet water detector; 27. Inlet flow meter. Detailed Implementation

[0024] The specific embodiments of this utility model will be further described below with reference to the accompanying drawings and examples. The following examples are only used to more clearly illustrate the technical solution of this utility model and should not be construed as limiting the scope of protection of this utility model.

[0025] See Figure 1-4 An integrated device for deep defluorination of wastewater includes a primary reaction mixing zone, a primary separation zone 6, a secondary reaction mixing zone, and a secondary separation zone 10 arranged in a row and connected in sequence. The bottom of the primary reaction mixing zone has an independent equipment compartment. The primary reaction mixing zone includes a primary reaction tank A2, a primary reaction tank B3, a coagulation tank 4, and a primary flocculation tank 5 arranged in a 2*2 plan and connected in sequence. The secondary reaction mixing zone includes a secondary reaction tank 7, a pH adjustment tank 8, and a secondary flocculation tank 9 arranged in a row and connected in sequence. Each of the primary reaction tanks A2, B3, 4, 7, and 8 is equipped with a lift-type aeration internal circulation device 12 and an aeration flushing device 13. Each of the primary flocculation tank 5 and 9 is equipped with an aeration flushing device 13 and a stirrer.

[0026] As shown in Figure 1, the aeration and flushing devices 13 are all arranged circumferentially along the inner wall of the tank, while the lifting aeration internal circulation device 12 or the agitator is located in the center of the tank. The primary flocculation tank 5 is equipped with a first agitator 14, and the secondary flocculation tank 9 is equipped with a second agitator 19.

[0027] The device described in this application is an integrated unit that connects the primary reaction mixing zone, the primary separation zone 6, the secondary reaction mixing zone, and the secondary separation zone 10 in a row. A sealed equipment compartment is located at the bottom of the primary reaction mixing zone, housing the blower, dosing device, and controller, making full use of vertical space and saving the overall footprint of the device. The equipment compartment is sealed from the primary reaction mixing zone and the primary separation zone, but it has windows opening to connect to the outside environment for pipes, wiring, etc., and for introducing air to power the blower.

[0028] This application adopts a modular design. Specifically, the primary reaction tank A2, primary reaction tank B3, coagulation tank 4, secondary reaction tank 7 and pH adjustment tank 8 have the same structure; the primary flocculation tank 5 and secondary flocculation tank 9 have the same structure; and the primary separation zone 6 and secondary separation zone 10 have the same structure.

[0029] The lifting aeration internal circulation device in this application uses an air source to drive internal circulation and aeration mixing, optimizing water flow, extending reaction time, avoiding short-circuiting, reducing mechanical failures, and saving operating costs. The aeration flushing device optimizes water flow, thereby reducing dead zones around the perimeter and corners of the pool. It also flushes the pool walls, using the physical energy of air (impact, scrubbing, vibration) to forcibly remove dirt and sticky substances from the pool wall surface, preventing scale buildup on the inner walls.

[0030] like Figure 4 As shown, the lifting aeration internal circulation device 12 includes an inner pipe 121 and an outer pipe 122 coaxially sleeved together, and a dosing chamber is formed between the inner pipe 121 and the outer pipe 122; the dosing device 21 adds the agent (such as defluorinating agent modified aluminum, iron, silicon polymer, etc., or flocculant) into the dosing chamber to mix with the wastewater.

[0031] The top end of the inner tube 121 is set as an air inlet 123, which extends to the outside of the pool and connects to an external air source. The bottom end of the inner tube extends to the outside of the outer tube and connects to an aerator 124 located at the bottom of the pool. The external air source enters the aerator 124 from the inner tube 121 and is released.

[0032] Specifically, the aerator 124 includes an aerator body and aeration branch pipes 125 spaced apart on the outer periphery of the aerator body. Aeration holes are provided on the aeration branch pipes 125. In this embodiment, the aerator body has a cylindrical structure, and six aeration branch pipes 125 are evenly arranged on its outer periphery. External air is evenly distributed from the aerator body to the six aeration branch pipes 125, which then diffuse the air to all areas of the pool through the aeration holes. The included angle between adjacent aeration branch pipes 125 is 60°, the length of a single aeration branch pipe is 10–50 cm, and both sides of the aeration branch pipe are inclined downwards at a 45° angle with 3–5 mm aeration holes. The distance between adjacent aeration holes is 50–100 mm.

[0033] The bottom of the outer pipe 122 is connected to an air pipe 127. The open end of the air pipe 127 is vertically upward and extends out of the pool to connect to an external air source, which is used to introduce the external air source into the dosing chamber to drive water circulation. In this embodiment, a regulating valve 128 is installed on the air pipe 127; the air volume is adjusted by controlling the regulating valve 128, thereby controlling the water volume of the internal circulation.

[0034] Specifically, the external air source enters the dosing chamber between the inner tube 121 and the outer tube 122 through the air pipe 127. The air flows upward along the dosing chamber, which in turn drives the wastewater to flow upward. The bottom funnel-shaped connecting cylinder 126 sucks up the bottom sewage, which flows upward along the outer tube and flows out from the upper outlet.

[0035] In a further embodiment, the top end of the inner tube 121 is fixedly connected to the top of the tank via a fixed bracket 129; the bottom end of the outer tube 122 is connected to a funnel-shaped connecting cylinder 126, which is smaller at the top and larger at the bottom, with the bottom diameter of the connecting cylinder 126 being 1.3 to 1.4 times the diameter of the outer tube 122. The purpose is to increase the water absorption capacity, allowing water from the bottom of the tank to easily enter the dosing chamber under the influence of gas flow, and then flow out from the top outlet, thus achieving water circulation. This accelerates the circulation of wastewater within the tank, ensuring sufficient contact between the wastewater and the chemicals, accelerating the dispersion and dissolution of the chemicals, thereby achieving the purpose of removing fluoride and flocculating large particulate impurities from the wastewater.

[0036] In this embodiment, the lifting aeration internal circulation device 12 is made of S31603 material, with a height H to diameter D ratio of 20:1 to 10:1, and an inner diameter ratio of 1:(2 to 5) between the inner tube 121 and the outer tube 122. Chemicals for each reaction zone are added into the outer tube 122, and rapid mixing and reaction are achieved through internal circulation stirring.

[0037] In another embodiment, the aeration and flushing device 13 includes a flushing pipe arranged circumferentially along the inner wall of the pool, one end of which is connected to an external air source, and a flushing hole is provided on the side of the flushing pipe facing the inner wall of the pool.

[0038] Specifically, multiple flushing pipes are installed from top to bottom, with the specific arrangement depending on the height of the pool and the level of wastewater inside, typically 2-3 layers. External air is introduced into the flushing pipes and then sprayed through the flushing holes towards the inner wall of the pool. This not only facilitates rapid mixing and reaction of the chemicals and wastewater, solving the problem of solution mixing in a square pool space, but also optimizes the water flow to reduce dead zones around the edges and corners. Simultaneously, it flushes the pool walls, using the physical energy of air (impact, scrubbing, vibration) to forcibly remove dirt and sticky substances from the pool wall surface, preventing scale buildup on the inner wall. The spacing between adjacent flushing pipes is 0.8–1 m; the distance between the flushing pipes and the inner wall of the pool is 8–15 cm; the flushing holes open towards the inner wall of the pool, with opening directions of horizontal, 45° upward, and 45° downward, and hole diameters of 3–5 mm. The distance between adjacent flushing holes is 30–50 mm.

[0039] like Figure 1-3 As shown, the primary separation region 6 and the secondary separation region 10 in this application have the same structure; the structure of the primary separation region 6 is described in detail below: The primary separation zone 6 has a sludge hopper at its bottom, and an inclined tube packing layer 17 above it. This divides the primary separation zone 6 into two areas along its depth: the upper inclined tube packing layer 17 is used for shallow sedimentation, and the bottom sludge hopper is used to collect the sediment. The outer wall of the sludge hopper is inclined at a 55° angle to the horizontal plane. No scraper is installed in the primary separation zone 6 to reduce equipment investment and the impact of scraper failure on equipment operation. The sludge settles naturally into the sludge hopper, which has an automatic sludge discharge valve at the bottom for static pressure sludge discharge, occurring 4-6 times per day. The inclined tube packing layer 17 is made of ethylene-propylene copolymer honeycomb inclined tube packing, with a 1m inclined length and an installation angle of 60°.

[0040] The primary separation zone 6 has an inlet overflow trough 15 and an inlet baffle 16 arranged longitudinally at its inlet end. The inlet overflow trough 15 is an L-shaped baffle fixed to the inner wall of the primary separation zone 6, forming an upward-opening trough structure. Wastewater discharged from the outlet at the top of the primary flocculation tank 5 first flows into the inlet overflow trough 15 and overflows evenly from the top of the inlet overflow trough 15, entering the gap between the inlet overflow trough 15 and the inlet baffle 16. Under the action of the inlet baffle 16, the water flows downwards and then changes direction to flow upwards at the bottom of the inlet baffle 16. That is, the wastewater enters the inclined tube packing layer 17 from the bottom of the inlet baffle 16, where sediment is separated. Therefore, the inlet overflow trough 15 and the inlet baffle 16 not only limit the water flow velocity in the primary separation zone 6 but also ensure that the water entering the primary separation zone 6 has a good hydraulic flow state, prolonging the reaction time, avoiding short-circuiting, and thus improving the sedimentation effect.

[0041] The lengths of the inlet overflow trough 15 and the inlet baffle 16 are both the same as the width of the primary separation zone 6. The top surface of the inlet overflow trough 15 is located between the outlet of the primary flocculation tank 5 and the liquid surface of the primary separation zone 6; the top surface of the inlet baffle 16 is flush with the top surface of the primary separation zone 6, and the bottom surface is located above the sludge hopper.

[0042] Specifically, in order to achieve the above effect, the distance between the water inlet overflow trough 15 and the water inlet baffle 16 is 20-50cm; the top surface of the water inlet overflow trough 15 is 5-10cm higher than the liquid surface of the primary separation zone 6. The distance between the bottom end of the water inlet baffle 16 and the mud hopper is 0.5 to 0.8 m, and the bottom of the water inlet baffle 16 is bent to guide the flow.

[0043] A backwashing device 18 for flushing the inclined tube packing layer 17 is fixed below it. The inclined tube packing layer 17 is formed by stacking inclined tube packing on a packing support. The backwashing device 18 is fixed to the bottom of the packing support by a hanger. The backwashing device 18 consists of a main pipe connected to several branch pipes, with a branch pipe spacing of 30-50 cm. The length of each branch pipe is 20-30 cm shorter than the width of the primary separation zone 6. Small holes are evenly spaced on the branch pipes, with holes on both sides and inclined downwards at 45°. An external air source is used to flush the inclined tube packing layer 17. The flushing frequency is once every 1-3 months, and the flushing intensity is 5-10 m. 3 / (m 2 This is because, during long-term operation, some lightweight, viscous flocculent sludge or other impurities will adhere to the inclined tube wall or accumulate in the gaps between the inclined tubes. This accumulation will lead to problems such as reduced effective flow area, decreased water flow capacity, and reduced treated water volume. The packing backwashing device 18 utilizes the powerful airflow impact force and bubble expansion force generated by the external air source to violently agitate and scrub the inclined tube packing, causing it to vibrate and deform, thereby peeling off and breaking down the stubborn dirt attached to its surface, suspending it in the water, and finally settling it to the bottom sludge hopper for discharge, restoring the flow capacity and settling efficiency of the inclined tube.

[0044] Both the primary separation zone and the secondary separation zone have sludge discharge ports at their bottoms, which are connected to the outlet of the sludge hopper.

[0045] In a further embodiment, the equipment compartment is equipped with a blower 20, a dosing device 21, and a controller 22. The blower 20 is used to provide an external air source for the lifting aeration internal circulation device 12 and the aeration flushing device 13. The dosing port of the dosing device 21 is connected to the lifting aeration internal circulation device 12 through a pipe.

[0046] In a further embodiment, the top of the primary reaction tank A2 is provided with an inlet 1 for introducing wastewater; the top of the secondary separation zone 10 is provided with an outlet 11; the wastewater enters the integrated device from the inlet 1, flows through each zone and water passage in sequence by gravity, and finally flows out through the outlet 11. The entire system automatically receives water and continuously discharges water.

[0047] An inlet water detector 25 for detecting fluoride is installed at inlet 1, and an outlet water detector 26 for detecting fluoride is installed at outlet 11; these are used to detect the fluoride content in wastewater. An inlet flow meter 27 is installed on inlet 1; a first pH meter 23 is installed in the primary reaction tank A2, and a second pH meter 24 is installed in the pH adjustment tank 8.

[0048] When the integrated device of this application is in operation: Fluoride-containing wastewater is pumped through inlet 1 into the reaction unit for defluorination treatment. The wastewater enters primary reaction tank A2, where calcium hydroxide is added to the dosing chamber of the lifting aeration internal circulation device 12 to control the pH value and perform chemical precipitation defluorination. The effluent then enters primary reaction tank B3, where calcium chloride is added to the dosing chamber of the lifting aeration internal circulation device 12. Fluoride reacts with calcium ions to form CaF2 precipitate.

[0049] The effluent flows sequentially into coagulation tank 4, primary flocculation tank 5, and primary separation zone 6. To facilitate rapid coagulation and sedimentation of the generated precipitates and achieve better sedimentation results, PAC is added to the dosing chamber of the lifting aeration internal circulation device 12 in coagulation tank 4, causing the entire dispersion system to become unstable and gradually coagulate. To rapidly coagulate the generated precipitates into larger flocs, PAM solution is added to primary flocculation tank 5. The effluent then flows through inlet overflow trough 15 and inlet baffle 16 into primary separation zone 6, and then through inclined tube packing layer 17 to complete the separation of fluoride-containing sludge and wastewater. The supernatant after separation flows by gravity through the upper outlet to the secondary reaction tank 7, pH adjustment tank 8, and secondary flocculation tank 9. At the same time, defluoridating agent is added to the dosing chamber of the lifting aeration internal circulation device 12 in the secondary reaction zone 7. The defluoridating agent removes low concentrations of fluoride from the wastewater through strong adsorption and ion exchange. Then, liquid alkali is added to the dosing chamber of the lifting aeration internal circulation device 12 in the pH adjustment zone 8 to adjust the pH environment required for the secondary deep defluorination reaction. Finally, PAM is added to the secondary flocculation tank 9. The effluent then enters the secondary separation zone 10, where the fluoride-containing sludge and wastewater are further separated. The supernatant obtained from the separation is discharged from the entire device through the upper outlet 11, completing the entire wastewater deep defluorination process.

[0050] The reagents required for each reaction zone in this device are added through the dosing device 21. The dosage of the reagents is as follows: the dosage of calcium hydroxide in the primary reaction tank A2 is to control the pH of the wastewater between 9 and 10; the dosage of calcium chloride is to control the molar ratio of calcium ions to fluoride in the primary reaction tank B3 to be 0.6 to 1.0; the dosage of PAC reagent 50 to 200 mg / L and PAM reagent 5 to 10 mg / L in the coagulation tank 4 and the primary flocculation tank 5 respectively (both based on the wastewater volume); the dosage of secondary defluoridating agent in the secondary reaction tank 7 is 0.5 to 1 g / L; the pH of the wastewater in the pH adjustment tank 8 is controlled between 6 and 7 by adding liquid alkali; and the dosage of flocculant PAM in the secondary flocculation tank 9 is 3 to 5 mg / L.

[0051] The integrated device of this invention has a first pH meter 23 installed in the primary reaction tank A2, a second pH meter 24 installed in the pH adjustment tank 8, an inlet water detector 25 for detecting fluoride and an inlet water flow meter 27 for measuring water volume installed at the inlet 1, and an outlet water detector 26 for detecting fluoride installed at the outlet 11. The pH meter, detectors, and inlet water flow meter are all conventional testing instruments in the field. These instruments are all connected to the controller 22 via wires or wireless communication, allowing the controller 22 to monitor multiple parameters in real time, such as wastewater flow rate, fluoride content, pH value, and equipment operation, and then control the dosing device for precise dosing.

[0052] After treatment by the integrated device of this application, the fluoride concentration in the wastewater is greatly reduced to 1 mg / L, which means that its deep defluorination effect is obvious.

[0053] Therefore, the integrated device for deep defluorination of wastewater provided in this application has high defluorination efficiency; at the same time, this integrated device has the advantages of high integration, simple operation and management and maintenance, low investment and operating costs, and has great engineering application value.

[0054] The above description is only a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present utility model, and these improvements and modifications should also be considered within the protection scope of the present utility model.

Claims

1. An integrated device for deep defluorination of wastewater, comprising a primary reaction mixing zone, a primary separation zone (6), a secondary reaction mixing zone, and a secondary separation zone (10) arranged in a row and connected in sequence, characterized in that: The bottom of the primary reaction mixing zone is provided with an independent equipment compartment. The primary reaction mixing zone includes a primary reaction tank A (2), a primary reaction tank B (3), a coagulation tank (4), and a primary flocculation tank (5) arranged in a 2*2 plane and connected in sequence. The secondary reaction mixing zone includes a secondary reaction tank (7), a pH adjustment tank (8), and a secondary flocculation tank (9) arranged in a row and connected in sequence. Each of the primary reaction tank A (2), primary reaction tank B (3), coagulation tank (4), secondary reaction tank (7), and pH adjustment tank (8) is equipped with a lift-type aeration internal circulation device (12) and an aeration flushing device (13). Each of the primary flocculation tank (5) and the secondary flocculation tank (9) is equipped with an aeration flushing device (13) and a stirrer.

2. The integrated device according to claim 1, characterized in that: The lifting aeration internal circulation device (12) includes an inner tube (121) and an outer tube (122) coaxially sleeved together, and a dosing chamber is formed between the inner tube (121) and the outer tube (122); The top end of the inner tube (121) extends to the outside of the pool and is connected to an external air source, and the bottom end of the inner tube extends to the outside of the outer tube and is connected to an aerator (124) located at the bottom of the pool. The bottom of the outer tube (122) is connected to an air tube (127) for introducing an external air source into the dosing chamber to drive water circulation.

3. The integrated device according to claim 2, characterized in that: The top end of the inner tube (121) is fixedly connected to the top of the pool via a fixed bracket (129); the bottom end of the outer tube (122) is connected to a connecting cylinder (126) that is flared and wider at the bottom than at the top.

4. The integrated device according to claim 2, characterized in that: A regulating valve (128) is installed on the air pipe (127); The aerator (124) includes an aerator body and aeration branch pipes (125) spaced apart on the outer periphery of the aerator body, and aeration holes are provided on the aeration branch pipes (125).

5. The integrated device according to claim 1, characterized in that: The aeration and flushing device (13) includes a flushing pipe arranged circumferentially along the inner wall of the pool. One end of the flushing pipe is connected to an external air source, and a flushing hole is provided on the side of the flushing pipe facing the inner wall of the pool.

6. The integrated device according to claim 5, characterized in that: Multiple flushing pipes are arranged from top to bottom, with a spacing of 0.8 to 1 m between adjacent flushing pipes; the distance between the flushing pipes and the inner wall of the pool is 8 to 15 cm. The flushing holes are opened in the horizontal, upward, and downward directions, respectively, with a diameter of 3-5 mm and a spacing of 30-50 mm between adjacent flushing holes.

7. The integrated device according to claim 1, characterized in that: The primary separation zone (6) and the secondary separation zone (10) have the same structure; The bottom of the primary separation zone (6) is provided with a mud hopper, and an inclined tube packing layer (17) is provided above the mud hopper. The inlet end of the primary separation zone (6) is provided with an inlet overflow trough (15) and an inlet baffle (16) in sequence; the top surface of the inlet overflow trough (15) is located between the outlet of the primary flocculation tank (5) and the liquid surface of the primary separation zone (6). The top of the water inlet baffle (16) is flush with the top surface of the primary separation zone (6), and the bottom is located above the mud hopper.

8. The integrated device according to claim 7, characterized in that: A packing backwashing device (18) for flushing the inclined tube packing layer is fixedly installed below the inclined tube packing layer (17). The distance between the water inlet overflow trough (15) and the water inlet baffle (16) is 20-50cm; the top surface of the water inlet overflow trough (15) is 5-10cm higher than the liquid surface of the primary separation zone (6); The distance between the bottom end of the water inlet baffle (16) and the mud hopper is 0.5 to 0.8 m, and the bottom of the water inlet baffle (16) is bent to guide the flow.

9. The integrated device according to claim 1, characterized in that: The equipment compartment is equipped with a blower (20), a dosing device (21), and a controller (22). The blower (20) is used to provide an external air source for the lifting aeration internal circulation device (12) and the aeration flushing device (13). The dosing port of the dosing device (21) is connected to the lifting aeration internal circulation device (12) through a pipe.

10. The integrated device according to claim 1, characterized in that: The top of the primary reaction tank A (2) is provided with an inlet (1) for introducing wastewater; the top of the secondary separation zone (10) is provided with an outlet (11). Both the inlet (1) and outlet (11) are equipped with detectors for detecting fluoride; an inlet flow meter (27) is installed on the inlet (1). pH meters are installed in both the primary reaction tank A (2) and the pH adjustment tank (8).

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