A three-stage fluorine removal device

Abstract

The utility model discloses a tertiary fluorine removal device, including frame, in the frame from liquid flow direction setting has one -level fluorine removal unit, two -level fluorine removal unit and tertiary fluorine removal unit in proper order, and each level fluorine removal unit includes reaction area and fluorine removal sedimentation tank, wherein reaction area is located the water inlet side, and the fluorine removal sedimentation tank is located the water outlet side of reaction area, wherein the reaction area of first fluorine removal unit is communicated with the processing liquid collection jar through the pipeline of installing peristaltic pump. The utility model discloses can control in stages, multistage collaborative fluorine removal. Through the construction three -level gradient processing system, realize the different treatment under the pollutant concentration gradually decreasing step by step, and establish the reaction pool function modular configuration, and optimize the reagent dosing timing and mixing intensity.

Description

Technical Field

[0001] This utility model relates to a water treatment device, specifically a three-stage defluoridation device. Background Technology

[0002] Fluoride, a common pollutant in industrial wastewater, poses a serious threat to the ecological environment and human health if discharged in excess. Traditional defluorination processes often employ single-stage chemical precipitation, using calcium and aluminum salts to form fluoride precipitates. However, this method suffers from problems such as high reagent consumption, low precipitation efficiency, and large fluctuations in effluent fluoride concentration. Especially for high-concentration fluoride wastewater (>100 mg / L), single-stage treatment often fails to meet national discharge standards (<10 mg / L). While multi-stage series treatment devices exist in current technologies, they generally suffer from inaccurate reagent dosing timing, leading to reagent waste and reduced flocculation effectiveness; and poor coordination between precipitation and reaction units. Particularly when treating high-concentration fluoride wastewater, traditional devices suffer from initial stage overload. When the initial fluoride concentration exceeds 500 mg / L, single-stage treatment often results in precipitate encapsulation, trapping unreacted fluoride ions within the precipitate and hindering further reaction. In addition, existing tertiary treatment equipment generally suffers from problems such as large footprint and uneven distribution of hydraulic retention time, resulting in high energy consumption and low treatment efficiency. Utility Model Content

[0003] Therefore, to address the aforementioned shortcomings, this invention provides a three-stage defluorination device capable of graded control and multi-stage synergistic defluorination. By constructing a three-stage gradient treatment system, differentiated treatment is achieved under progressively decreasing pollutant concentrations; a modular configuration of the reaction tank is established, optimizing the reagent dosing sequence and mixing intensity.

[0004] Specifically, a three-stage defluorination device includes a frame in which a primary defluorination unit, a secondary defluorination unit, and a tertiary defluorination unit are arranged sequentially from the direction of liquid flow. Each defluorination unit includes a reaction zone and a defluorination sedimentation tank, wherein the reaction zone is located on the inlet side and the defluorination sedimentation tank is located on the outlet side of the reaction zone.

[0005] The reaction zone of the first defluorination unit is connected to the treatment liquid collection tank via a pipe equipped with a peristaltic pump.

[0006] Optionally, the reaction zone of the primary defluorination unit is provided with a primary first reaction tank, a primary second reaction tank, a primary third reaction tank and a primary fourth reaction tank in sequence. Each reaction tank is equipped with a stirrer, which is arranged along one side of the defluorination sedimentation tank of the primary defluorination unit.

[0007] The first primary reaction tank is a pH adjustment tank, which is connected to the second primary reaction tank via overflow. The second primary reaction tank is a defluorination agent dosing tank, and its lower part is connected to the third primary reaction tank. The third primary reaction tank is a PAC agent dosing tank, which is connected to the fourth primary reaction tank via overflow. The fourth primary reaction tank is a PAM agent dosing tank, and its lower part is connected to the defluorination sedimentation tank of the first primary defluorination unit.

[0008] Optionally, the reaction zone of the secondary defluorination unit is provided with a secondary first reaction tank, a secondary second reaction tank and a secondary third reaction tank in sequence. All three reaction tanks are equipped with a stirrer and are arranged along one side of the defluorination sedimentation tank of the secondary defluorination unit.

[0009] The secondary first reaction tank is used for pH adjustment and defluorination dosing. The secondary first reaction tank is connected to the defluorination sedimentation tank of the primary defluorination unit via overflow. The secondary second reaction tank is a PAC reagent dosing tank, and its lower part is connected to the lower part of the secondary first reaction tank. The secondary third reaction tank is a PAM reagent dosing tank, and its secondary third reaction tank is connected to the secondary second reaction tank via overflow. Its lower part is connected to the lower part of the defluorination sedimentation tank of the secondary defluorination unit.

[0010] Optionally, the reaction zone of the three-stage defluorination unit is provided with a three-stage first reaction tank, a three-stage second reaction tank and a three-stage third reaction tank in sequence. All three reaction tanks are equipped with a stirrer and are arranged along one side of the defluorination sedimentation tank of the three-stage defluorination unit.

[0011] The first reaction tank of the third stage is used for pH adjustment and defluorination dosing. The first reaction tank of the third stage is connected to the defluorination sedimentation tank of the second defluorination unit through overflow. The second reaction tank of the third stage is a PAC reagent dosing tank. The lower part of the second reaction tank of the third stage is connected to the lower part of the first reaction tank of the third stage. The third reaction tank of the third stage is a PAM reagent dosing tank. The third reaction tank of the third stage is connected to the second reaction tank of the third stage through overflow. The lower part of the third reaction tank of the third stage is connected to the lower part of the defluorination sedimentation tank of the third defluorination unit.

[0012] This utility model has the following advantages:

[0013] This invention is a three-stage defluorination device capable of graded control and multi-stage synergistic defluorination. By constructing a three-stage gradient treatment system, it achieves differentiated treatment under progressively decreasing pollutant concentrations; it establishes a modular configuration for the reaction tank and optimizes the timing of reagent addition and mixing intensity.

[0014] This invention is an integrated reaction and precipitation device with a compact structure, facilitating installation. Each reaction zone is equipped with a dosing pump and flow meter, enabling precise dosing. Users can experimentally determine the reaction and defluorination effect under different concentrations and dosages. Simultaneously, each reaction tank is equipped with a stirrer to ensure uniform mixing and thorough reaction of the reagents. Furthermore, this invention uses a peristaltic pump to drive the liquid, allowing for precise control of the influent flow and simulating defluorination reactions under different operating conditions. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the structure of this utility model;

[0016] Figure 2 This is a top view of the present invention;

[0017] Figure 3 This is a front view schematic diagram of the installed state of this utility model;

[0018] Figure 4 yes Figure 1 Sectional view of AA;

[0019] Figure 5 yes Figure 1 Cross-sectional view of BB (M in the figure indicates the water level);

[0020] Figure 6 yes Figure 1 Sectional view of CC;

[0021] Figure 7 yes Figure 1 Sectional view of DD;

[0022] Figure 8 yes Figure 1 Sectional view of EE;

[0023] In the diagram: 10. Primary defluorination sedimentation tank; 11. Primary first reaction tank; 12. Primary second reaction tank; 13. Primary third reaction tank; 14. Primary fourth reaction tank; 20. Secondary defluorination sedimentation tank; 21. Secondary first reaction tank; 22. Secondary second reaction tank; 23. Secondary third reaction tank; 30. Tertiary defluorination sedimentation tank; 31. Tertiary first reaction tank; 32. Tertiary second reaction tank; 33. Tertiary third reaction tank; 40. Peristaltic pump; 50. Processing liquid collection tank; 60. Tonnage container. Detailed Implementation

[0024] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application.

[0025] In this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, without necessarily requiring or implying any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus.

[0026] As described in the background section, although multi-stage series treatment devices exist in the prior art, they generally suffer from inaccurate control of reagent dosing timing, leading to reagent waste and reduced flocculation effect; the sedimentation unit and reaction unit are also poorly connected. Especially when treating high-concentration fluoride wastewater, traditional devices suffer from overload of the first-stage treatment. When the initial fluoride concentration exceeds 500 mg / L, single-stage treatment often results in precipitate encapsulation, preventing unreacted fluoride ions from continuing the reaction. Furthermore, existing tertiary treatment equipment generally suffers from large footprint and uneven hydraulic retention time distribution, leading to high energy consumption and low treatment efficiency.

[0027] For the reasons mentioned above, this embodiment provides a three-stage defluorination device, such as... Figures 1-4 As shown, the device includes a frame in which a primary defluorination unit, a secondary defluorination unit, and a tertiary defluorination unit are arranged sequentially from the direction of liquid flow. Each defluorination unit includes a reaction zone and a defluorination sedimentation tank, wherein the reaction zone is located on the inlet side and the defluorination sedimentation tank is located on the outlet side of the reaction zone.

[0028] The reaction zone of the first defluorination unit is connected to the treatment liquid collection tank 50 via a pipeline equipped with a peristaltic pump 40, and the defluorination sedimentation tank of the third defluorination unit is connected to the ton tank 60.

[0029] The primary defluorination unit includes a primary defluorination sedimentation tank 10 and a primary reaction zone. The primary reaction zone of the primary defluorination unit is provided with a primary first reaction tank 11, a primary second reaction tank 12, a primary third reaction tank 13 and a primary fourth reaction tank 14 in sequence. Each reaction tank is equipped with a stirrer, which is arranged along one side of the defluorination sedimentation tank of the primary defluorination unit.

[0030] The first primary reaction tank is a pH adjustment tank, which is connected to the second primary reaction tank via overflow. The second primary reaction tank is a defluorination agent dosing tank, and its lower part is connected to the third primary reaction tank. The third primary reaction tank is a PAC agent dosing tank, which is connected to the fourth primary reaction tank via overflow. The fourth primary reaction tank is a PAM agent dosing tank, and its lower part is connected to the defluorination sedimentation tank of the first primary defluorination unit.

[0031] The secondary defluorination unit includes a secondary defluorination sedimentation tank 20 and a secondary reaction zone. The secondary reaction zone is provided with a secondary first reaction tank 21, a secondary second reaction tank 22 and a secondary third reaction tank 23 in sequence. All three reaction tanks are equipped with a stirrer and are arranged along one side of the defluorination sedimentation tank of the secondary defluorination unit.

[0032] The secondary first reaction tank is used for pH adjustment and defluorination dosing. The secondary first reaction tank is connected to the defluorination sedimentation tank of the primary defluorination unit via overflow. The secondary second reaction tank is a PAC reagent dosing tank, and its lower part is connected to the lower part of the secondary first reaction tank. The secondary third reaction tank is a PAM reagent dosing tank, and its secondary third reaction tank is connected to the secondary second reaction tank via overflow. Its lower part is connected to the lower part of the defluorination sedimentation tank of the secondary defluorination unit.

[0033] The three-stage defluorination unit includes a three-stage defluorination sedimentation tank 30 and a three-stage reaction zone. The three-stage reaction zone is provided with a three-stage first reaction tank 31, a three-stage second reaction tank 32 and a three-stage third reaction tank 33 in sequence. Each of the three reaction tanks is equipped with a stirrer, which is arranged along one side of the defluorination sedimentation tank of the three-stage defluorination unit.

[0034] The first reaction tank of the third stage is used for pH adjustment and defluorination dosing. The first reaction tank of the third stage is connected to the defluorination sedimentation tank of the second defluorination unit through overflow. The second reaction tank of the third stage is a PAC reagent dosing tank. The lower part of the second reaction tank of the third stage is connected to the lower part of the first reaction tank of the third stage. The third reaction tank of the third stage is a PAM reagent dosing tank. The third reaction tank of the third stage is connected to the second reaction tank of the third stage through overflow. The lower part of the third reaction tank of the third stage is connected to the lower part of the defluorination sedimentation tank of the third defluorination unit.

[0035] Each reaction tank is equipped with a dosing pump and a flow meter to facilitate precise control of the dosage.

[0036] The usage process of this utility model is as follows:

[0037] Primary defluorination unit treatment stage:

[0038] Initial feed: Fluoride-containing wastewater is quantitatively transported from the treatment liquid collection tank to the first-stage reaction tank (pH adjustment tank) via a peristaltic pump. The wastewater is adjusted to a preset pH range (usually 6.5-7.5) by a pH sensor and an automatic acid / alkali addition system to optimize subsequent reaction conditions.

[0039] Overflow transfer: The regulated wastewater overflows into the first-stage second reaction tank (fluoride removal agent dosing tank), where calcium or aluminum salt fluoride removal agents (such as CaO, CaCl2 or Al2(SO4)3) are added. The mixture is forced to form fluoride precipitate nuclei by a stirrer.

[0040] Cascade reaction: The mixed liquor flows from the bottom of the first-stage second reaction tank into the first-stage third reaction tank (PAC reagent addition tank), where polyaluminum chloride (PAC) is added to promote the coagulation of micro flocs; then it overflows into the first-stage fourth reaction tank (PAM reagent addition tank), where polyacrylamide (PAM) is added to enhance the floc bridging effect and form large floc particles.

[0041] Sedimentation and separation: The flocculated mixture enters the first-stage defluorination sedimentation tank from the bottom of the fourth reaction tank of the first stage. Solid-liquid separation is achieved through inclined plate sedimentation technology. The supernatant overflows into the first reaction tank of the second stage, and the bottom sediment is periodically discharged through the sludge discharge valve.

[0042] Secondary defluorination unit treatment stage:

[0043] Secondary reaction enhancement: The supernatant from the primary sedimentation tank enters the secondary first reaction tank, where the pH is finely adjusted (usually to 7.0-7.8) and a defluorinating agent is added to further reduce the concentration of residual fluoride ions.

[0044] Circulating dosing: The mixed liquid from the first reaction tank of the secondary stage enters the second reaction tank of the secondary stage (PAC dosing tank) through the bottom overflow port, and PAC is added again to enhance the flocculation effect; then it overflows to the third reaction tank of the secondary stage (PAM dosing tank) to form dense flocs.

[0045] Synergistic sedimentation: The mixed liquid from the secondary and third reaction tanks enters the secondary defluorination sedimentation tank through the bottom overflow port. A guide tube is installed in the sedimentation tank to extend the hydraulic residence time and enhance the settling of fine particles. The supernatant overflows to the tertiary first reaction tank.

[0046] Three-stage defluorination unit treatment phase:

[0047] Advanced treatment: The supernatant from the secondary sedimentation tank enters the tertiary first reaction tank for final pH adjustment (7.5-8.0) and addition of a high-efficiency defluorinating agent to deeply remove residual fluoride ions (<10mg / L).

[0048] High-efficiency flocculation: The mixed liquor flows sequentially through the third-stage second reaction tank (PAC addition tank) and the third-stage third reaction tank (PAM addition tank), and the flocs are compacted by step-by-step stirring intensity control (gradually reducing the speed).

[0049] Final separation: The mixed liquid from the third reaction tank of the three stages enters the third defluoridation sedimentation tank through the bottom outlet. The shallow sedimentation design accelerates the separation of mud and water, and the final effluent fluoride concentration is reduced to below 2 mg / L, meeting the discharge standards.

[0050] During implementation, the system can be coordinated and controlled:

[0051] Dynamic feedback: Each pH adjustment tank is equipped with an online monitoring instrument that links the peristaltic pump and the dosing pump in real time to ensure that the dosage of the chemicals is dynamically matched with water quality fluctuations.

[0052] Sludge recycling: Some of the sludge at the bottom of the tertiary sedimentation tank can be recycled back to the first primary reaction tank, utilizing unreacted reagents to improve resource utilization.

[0053] Continuous operation: Gravity flow is achieved through overflow weir and pipeline slope design, combined with precise metering by peristaltic pumps, ensuring balanced hydraulic load of the three-stage treatment units and forming a continuous treatment process.

[0054] For example, the parameters of the three-stage defluorination device are shown in Table 1 below.

[0055] Table 1: Parameter Table

[0056]

[0057] In the table above: Primary reaction tank 1 is the first primary reaction tank, primary reaction tank 2 is the second primary reaction tank, primary reaction tank 3 is the third primary reaction tank, primary reaction tank 4 is the fourth primary reaction tank, and primary sedimentation tank is the first primary defluorination sedimentation tank; Secondary reaction tank 1 is the first secondary reaction tank, secondary reaction tank 2 is the second secondary reaction tank, secondary reaction tank 3 is the third secondary reaction tank, secondary reaction tank 4 is the fourth secondary reaction tank, and secondary sedimentation tank is the second secondary defluorination sedimentation tank; Tertiary reaction tank 1 is the first tertiary reaction tank, tertiary reaction tank 2 is the second tertiary reaction tank, tertiary reaction tank 3 is the third tertiary reaction tank, tertiary reaction tank 4 is the fourth tertiary reaction tank, and tertiary sedimentation tank is the third tertiary defluorination sedimentation tank.

[0058] This invention is an integrated reaction and precipitation device with a compact structure, facilitating installation. Each reaction zone is equipped with a dosing pump and flow meter, enabling precise dosing. Users can experimentally determine the reaction and defluorination effect under different concentrations and dosages. Simultaneously, each reaction tank is equipped with a stirrer to ensure uniform mixing and thorough reaction of the reagents. Furthermore, this invention uses a peristaltic pump to drive the liquid, allowing for precise control of the influent flow and simulating defluorination reactions under different operating conditions.

[0059] The above description of the disclosed embodiments enables those skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A three-stage defluorination device, characterized in that: The device includes a frame in which a primary defluorination unit, a secondary defluorination unit, and a tertiary defluorination unit are arranged sequentially from the direction of liquid flow. Each defluorination unit includes a reaction zone and a defluorination sedimentation tank, wherein the reaction zone is located on the inlet side and the defluorination sedimentation tank is located on the outlet side of the reaction zone. The reaction zone of the first defluorination unit is connected to the treatment liquid collection tank via a pipe equipped with a peristaltic pump. The reaction zone of the primary defluorination unit is provided with a first primary reaction tank, a second primary reaction tank, a third primary reaction tank, and a fourth primary reaction tank in sequence. Each reaction tank is equipped with a stirrer, which is arranged along one side of the defluorination sedimentation tank of the primary defluorination unit. The first primary reaction tank is a pH adjustment tank, which is connected to the second primary reaction tank via overflow. The second primary reaction tank is a defluorination agent dosing tank, and its lower part is connected to the third primary reaction tank. The third primary reaction tank is a PAC agent dosing tank, which is connected to the fourth primary reaction tank via overflow. The fourth primary reaction tank is a PAM agent dosing tank, and its lower part is connected to the defluorination sedimentation tank of the first primary defluorination unit. The reaction zone of the secondary defluorination unit is provided with a secondary first reaction tank, a secondary second reaction tank and a secondary third reaction tank in sequence. All three reaction tanks are equipped with a stirrer and are arranged along one side of the defluorination sedimentation tank of the secondary defluorination unit. The secondary first reaction tank is used for pH adjustment and defluorination dosing, and is connected to the defluorination sedimentation tank of the primary defluorination unit via overflow. The secondary second reaction tank is a PAC reagent dosing tank, and its lower part is connected to the lower part of the secondary first reaction tank. The secondary third reaction tank is a PAM reagent dosing tank, and is connected to the secondary second reaction tank via overflow, and its lower part is connected to the lower part of the defluorination sedimentation tank of the secondary defluorination unit. The reaction zone of the three-stage defluorination unit is provided with a three-stage first reaction tank, a three-stage second reaction tank and a three-stage third reaction tank in sequence. All three reaction tanks are equipped with a stirrer and are arranged along one side of the defluorination sedimentation tank of the three-stage defluorination unit. The first reaction tank of the third stage is used for pH adjustment and defluorination dosing. The first reaction tank of the third stage is connected to the defluorination sedimentation tank of the second defluorination unit through overflow. The second reaction tank of the third stage is a PAC reagent dosing tank. The lower part of the second reaction tank of the third stage is connected to the lower part of the first reaction tank of the third stage. The third reaction tank of the third stage is a PAM reagent dosing tank. The third reaction tank of the third stage is connected to the second reaction tank of the third stage through overflow. The lower part of the third reaction tank of the third stage is connected to the lower part of the defluorination sedimentation tank of the third defluorination unit.

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