Integrated device for defluorination of fluorine-containing wastewater

Abstract

This invention discloses an integrated device for defluoridation of fluoride-containing wastewater, comprising a tank with a fixed water collection and regulating tank extending above the tank to collect the fluoride-containing wastewater to be treated and to buffer and regulate the influent flow rate. Multiple partitions are installed inside the tank, fixedly connected to the inner wall of the tank and the outer wall of the water collection and regulating tank. These partitions are arranged in a ring array, dividing the tank interior into multiple sector-shaped cavities. Each sector-shaped cavity is an independent reaction unit integrating calcium salt reaction, pH adjustment, and flocculation reaction. This invention solves the problem of intermittent operation and overall treatment interruption due to waiting for a certain process in traditional series-connected multi-tank structures, achieving continuous influent and effluent while ensuring sufficient residence time in each reaction stage, thus overcoming the contradiction between continuous flow and thorough reaction in existing technologies.

Description

Technical Field

[0001] This invention relates to the field of environmental protection equipment technology, and in particular to an integrated device for defluorinating fluoride-containing wastewater. Background Technology

[0002] Traditional methods for treating fluoride-containing wastewater typically employ a combination of calcium salt precipitation and flocculation sedimentation. This involves sequentially setting up a calcium salt reaction tank, a pH adjustment tank, a flocculation reaction tank, and a sedimentation tank, with each functional tank connected in series via pipelines. Wastewater flows through each tank sequentially to complete the treatment process. Because each reaction stage occurs independently in different tanks, the entire system requires a large floor space, involves high equipment investment, and has complex piping connections.

[0003] Meanwhile, traditional series-connected multi-tank structures suffer from significant issues of process waiting and incomplete reaction during actual operation. When a tank requires a long time for reaction or sedimentation, subsequent processes are forced to shut down, resulting in intermittent operation and low treatment efficiency. If the retention time in each tank is shortened to maintain continuous influent, calcium salt reaction is insufficient and floc growth is incomplete, making it difficult to consistently meet the effluent fluoride concentration standards. In other words, there is a contradiction between continuous flow and thorough reaction, making it difficult to achieve both simultaneously. Therefore, providing an integrated device for defluoridation of fluoride-containing wastewater is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0004] One objective of this invention is to provide an integrated device for defluorination of fluoride-containing wastewater. This invention solves the problem of interrupted overall treatment and intermittent operation caused by waiting for a certain process in the traditional series multi-tank structure. It achieves continuous influent and effluent while ensuring sufficient residence time in each reaction stage, thus overcoming the contradiction between continuous flow and thorough reaction in the prior art.

[0005] An integrated device for defluoridation of fluoride-containing wastewater according to an embodiment of the present invention includes a housing. A water collection and regulating tank is fixed within the housing, with its top extending above the housing for collecting the fluoride-containing wastewater to be treated and for buffering and regulating the influent flow rate. Multiple partitions are installed inside the housing, fixedly connected to the inner wall of the housing and the outer wall of the water collection and regulating tank. These partitions are arranged in a circular array, dividing the interior of the housing into multiple sector-shaped cavities. Each sector-shaped cavity is an independent reaction unit integrating calcium salt reaction, pH adjustment, and flocculation reaction, and each cavity can independently complete all the aforementioned reaction processes. Furthermore, multiple water distribution pipes, corresponding one-to-one with the sector-shaped cavities, are installed on the water collection and regulating tank. The upper end of the water distribution pipes is higher than the top surface of the housing, allowing the wastewater in the water collection and regulating tank to flow by gravity into each sector-shaped cavity due to the liquid level difference. Multiple water distribution pipes are equipped with solenoid valves, all of which are electrically connected to a single controller. The controller controls the flow of water into designated sector chambers by switching the on / off states of each solenoid valve, thus achieving independent control of the water inlet sequence for each sector chamber. Furthermore, each sector chamber is equipped with an aeration pipe for supplying air to the inside of the sector chamber, achieving stirring for calcium salt reaction, pH adjustment, and micro-disturbance during the flocculation stage. Each sector chamber is also equipped with a level sensor, a fluoride ion sensor, and a pH sensor, all electrically connected to the controller. These sensors collect the level signal, fluoride ion concentration signal, and pH value signal from within the sector chamber and feed them back to the controller in real time. Additionally, a blower is included, with its outlet pipe connected to a main pipe, which in turn connects to a first branch and a second branch. The first branch connects to the air inlet of the Venturi tube, and the air outlet of the Venturi tube connects to multiple drug delivery pipelines. Each drug delivery pipeline is equipped with a drug delivery solenoid valve, and the ends of these pipelines are connected to the front end of the aeration pipe of the corresponding sector cavity. The second branch connects to multiple gas delivery pipelines, the ends of which are connected to the front end of the aeration pipe of the corresponding sector cavity. Each gas delivery pipeline is equipped with a gas delivery solenoid valve. Within each sector cavity, the drug delivery pipeline and the gas delivery pipeline converge at the front end of the aeration pipe, sharing the same aeration pipe to deliver gas into the sector cavity. Furthermore, a suction pipe is installed at the throat of the Venturi tube. This suction pipe connects to calcium solution storage tanks, acid solution storage tanks, alkali solution storage tanks, PAC reagent storage tanks, and PAM reagent storage tanks via multiple independent suction branches. Each suction branch is equipped with a reagent storage tank solenoid valve and a flow meter. A proportional solenoid valve is installed at the front end of the aeration pipe. Each flow meter, chemical storage tank solenoid valve, drug delivery solenoid valve, gas delivery solenoid valve, and proportional solenoid valve is electrically connected to the controller.The airflow from the blower enters the venturi tube, generating negative pressure at the throat. By controlling the sequential opening and closing of the solenoid valves of each drug storage tank, the corresponding drug in the tank can be selectively drawn in. The drawn-in drug is then carried by the airflow through the delivery pipeline and aeration pipe into the corresponding sector cavity, achieving pneumatic delivery and automatic drug dosing. The controller controls the opening and closing of the delivery solenoid valve and the air delivery solenoid valve. During the dosing stage, the delivery solenoid valve is opened and the air delivery solenoid valve is closed; during the stirring stage, the delivery solenoid valve is closed and the air delivery solenoid valve is opened, allowing the two airflows to selectively flow and be delivered into the sector cavity through the same aeration pipe at different times. Furthermore, each sector cavity has a drain pipe in the lower middle part of its side wall and a sludge discharge pipe at the bottom. A drain solenoid valve and a sludge discharge solenoid valve are respectively installed on the drain pipe and the sludge discharge pipe, and both are electrically connected to the controller. After the reaction in each sector cavity is completed and the mixture settles, the supernatant is discharged through the drain pipe and collected and transported to the subsequent flotation unit for flotation and sludge removal. The bottom sludge is discharged through the sludge discharge pipe. Preferably, the aeration pipe adopts a segmented combined structure, consisting of a connecting pipe penetrating the top of the tank and a spiral pipe located at the bottom of the connecting pipe. The connecting pipe and the spiral pipe are an integral, interconnected structure, allowing the airflow and reagent mixture to flow smoothly throughout the pipe without any dead ends. The connecting pipe is vertically fixed to the inner side of the sector cavity near the cavity wall, and the top of the connecting pipe is connected to the end interface of the air supply pipeline and the reagent supply pipeline, serving as the main inlet section for air and reagent intake. The spiral pipe is suspended in the lower part of the inner cavity of the sector cavity, maintaining a distance of 10-15 cm from the bottom surface of the sector cavity. The spiral pipe adopts a spiral winding structure that gradually expands from the inside to the outside, and its overall shape is adapted to the bottom contour of the sector cavity. The spiral tube is uniformly equipped with several aeration nozzles, which are arranged obliquely downwards or laterally to achieve uniform and fine aeration from the middle to the bottom of the water body. Furthermore, the controller has a preset time-series control program for multiple sector-shaped cavities. Each sector-shaped cavity is in a different reaction stage at the same time, and the start-up time interval between adjacent sector-shaped cavities is equal. At any given time, at least one sector-shaped cavity is in the water inlet stage, at least one sector-shaped cavity is in the chemical dosing reaction stage, and at least one sector-shaped cavity is in the sedimentation or drainage stage. Under the time-series control of the controller, each sector-shaped cavity operates alternately with staggered phases, thereby achieving continuous and uninterrupted treatment of fluoride-containing wastewater.

[0006] Preferably, the wastewater in the collection and regulating tank naturally stratifies after settling, with the upper part being supernatant and the bottom part being sediment. The inlet of the water distribution pipe is located in the upper area of ​​the collection and regulating tank, so that the water entering the water distribution pipe is mainly supernatant with low suspended solids content. After a certain sector cavity has completed drainage and sludge removal, the controller performs the following cleaning operation: the controller controls the solenoid valve of the water distribution pipe corresponding to the sector cavity to open and close in a pulse manner. Each time it is opened, the supernatant in the upper part of the collection and regulating tank enters the water distribution pipe. The outlet of the water distribution pipe is located at the upper part of the sector cavity, so the supernatant will fall to the bottom of the sector cavity under the action of gravity, thereby breaking up some of the sludge remaining at the bottom. During the interval of pulse water inflow, the controller opens the air supply solenoid valve and adjusts the proportional solenoid valve to the maximum opening, so that the high-pressure airflow is sprayed out from the aeration nozzle through the aeration pipe, which performs short-term intense aeration on the water in the cavity, further stirring up the broken sludge and suspending it in the supernatant. Then the aeration is turned off, and the sludge-containing wastewater is discharged through the sludge discharge pipe. Repeat the above pulse water intake and intermittent aeration steps multiple times until the residual sludge at the bottom of the fan-shaped cavity is gradually carried away.

[0007] The beneficial effects of this invention are: 1. This invention integrates calcium salt reaction, pH adjustment, and flocculation reaction into a single sector-shaped cavity for independent completion, eliminating the need for multiple series-connected functional tanks and saving equipment floor space. Simultaneously, multiple sector-shaped cavities operate sequentially and alternately under the timing control of the controller, ensuring that while some cavities are in the reaction or sedimentation stage, the remaining cavities can still receive water normally. This solves the problem of interrupted overall treatment and intermittent operation caused by waiting for a certain process in traditional series-connected multi-tank structures, achieving continuous water intake and output while ensuring sufficient residence time for each reaction stage, thus overcoming the contradiction between continuous flow and thorough reaction in existing technologies.

[0008] 2. By setting up a first branch and a second branch, the same air source provided by the blower is divided into two paths. One path carries the medicine into the sector cavity through the Venturi tube, and the other path directly sends it into the sector cavity through the air delivery pipeline. The negative pressure generated at the throat of the Venturi tube realizes the automatic suction and delivery of the medicine. There is no need to set up a separate dosing pump, which simplifies the equipment structure and reduces the operating energy consumption.

[0009] 3. This invention uses a flow meter to collect the flow rate of the reagent in real time and feeds it back to the controller. The controller calculates the required dosage of the corresponding reagent based on the detection signals from the fluoride ion sensor and pH sensor, and accurately controls the dosage based on the cumulative flow to achieve quantitative and precise dosing. After the reaction, the sensor detects again, and if the standard is not met, additional dosing is added, forming a closed-loop intelligent control, avoiding insufficient or excessive waste of reagents, and improving the stability of the effluent water quality.

[0010] 4. By setting a proportional solenoid valve, the controller can adjust the aeration intensity according to different reaction stages: in the calcium salt reaction and pH adjustment stages, it provides high-flow-rate strong aeration and stirring to make the agent and wastewater mix quickly and thoroughly; in the flocculation stage, it switches to micro-disturbance aeration, which can prevent the flocculant from settling and accumulating, and avoid the floc breakage caused by violent water flow impact. It takes into account the different requirements of aeration intensity for different processes and improves the flocculation and sedimentation effect.

[0011] 5. The aeration pipe in this invention differs from the traditional bottom-fitting straight pipe aeration structure. It avoids the problems of bottom sediment clogging aeration points and siltation polluting the pipeline. Furthermore, the spirally arranged aeration nozzles can create a vortex stirring in the chamber, eliminating dead zones at the bottom of the chamber and improving reaction uniformity and treatment efficiency.

[0012] 6. During cleaning, the controller can complete the cleaning using the existing water distribution pipe, aeration pipe and sludge discharge pipe by simply changing the opening and closing sequence of the water distribution solenoid valve and the air supply solenoid valve. No additional cleaning water pump, cleaning pipeline or external clean water source is required. The cleaning medium is the supernatant in the water collection and regulating tank after settling and stratification, which does not consume external clean water. The alternating action of pulse water inlet and intermittent aeration helps to disperse the bottom sludge and stir and suspend the sludge, thereby improving the cleaning efficiency. Attached Figure Description

[0013] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings: Figure 1 This is a schematic diagram of the integrated device for defluorination of fluoride-containing wastewater proposed in this invention; Figure 2 This is a cross-sectional structural schematic diagram of an integrated device for defluorination of fluoride-containing wastewater proposed in this invention.

[0014] Figure 3 This is a top sectional view of the casing in an integrated device for defluorination of fluoride-containing wastewater proposed in this invention.

[0015] Figure 4 This is a schematic diagram of the gas path arrangement in an integrated device for defluorination of fluoride-containing wastewater proposed in this invention.

[0016] Figure 5 for Figure 4 Enlarged view of part of the image.

[0017] Figure 6 This is a schematic diagram of the spiral tube structure in an integrated device for defluorination of fluoride-containing wastewater proposed in this invention.

[0018] Figure 7This is a bottom view of the spiral tube structure in the integrated device for defluorination of fluoride-containing wastewater proposed in this invention.

[0019] Figure 8 This is a control logic block diagram of an integrated device for defluorination of fluoride-containing wastewater proposed in this invention.

[0020] Figure 9 This is a block diagram of the gas path layout for an integrated device for defluorination of fluoride-containing wastewater proposed in this invention.

[0021] In the diagram: 1. Box body; 2. Water collection and regulating tank; 3. Baffle plate; 4. Sector-shaped cavity; 5. Water distribution pipe; 6. Liquid level sensor; 7. Fluoride ion sensor; 8. pH sensor; 9. Blower; 10. Venturi tube; 11. Drug delivery pipeline; 12. Connecting pipe; 13. Proportional solenoid valve; 14. Gas delivery pipeline; 15. Aeration pipe; 16. Drainage pipe; 17. Sludge discharge pipe; 18. Calcium solution storage tank; 19. Acid solution storage tank; 20. Alkali solution storage tank; 21. PAC reagent storage tank; 22. PAM reagent storage tank; 23. Spiral tube; 24. Aeration nozzle. Detailed Implementation

[0022] The present invention will now be described in further detail with reference to the accompanying drawings. These drawings are simplified schematic diagrams, illustrating only the basic structure of the invention, and therefore only show the components relevant to the invention.

[0023] Example 1 refer to Figure 1-9 The integrated device for defluorination of fluoride-containing wastewater includes a housing 1, in which a water collection and regulating tank 2 is fixed. The top of the water collection and regulating tank 2 extends above the housing 1 to collect fluoride-containing wastewater. Multiple partitions 3 are installed inside the housing 1. The partitions 3 are fixed to the inner wall of the housing 1 and the outer wall of the water collection and regulating tank 2. The multiple partitions 3 are arranged in a ring array, dividing the interior of the housing 1 into multiple fan-shaped cavities 4. Each fan-shaped cavity 4 can independently complete calcium salt reaction, pH adjustment and flocculation reaction, integrating multi-step treatment functions in the same chamber.

[0024] The water collection and regulating tank 2 is equipped with multiple water distribution pipes 5 that are connected to the sector cavity 4. The upper end of the water distribution pipe 5 is higher than the height of the tank body 1, which allows the sewage in the water collection and regulating tank 2 to flow directly into the sector cavity 4 through the water level difference. Each of the multiple water distribution pipes 5 is equipped with a water distribution pipe solenoid valve, and the multiple water distribution pipe solenoid valves are electrically connected to the same controller. By switching the on and off of each water distribution pipe solenoid valve, the water inlet can be controlled to flow to the designated sector cavity 4.

[0025] Each of the multiple sector-shaped cavities 4 is equipped with an aeration pipe 15, which is used to supply air into the sector-shaped cavity 4 to achieve stirring of calcium salt reaction, stirring of pH adjustment, and micro-disturbance during the flocculation stage. The sector-shaped cavity 4 is also equipped with a liquid level sensor 6, a fluoride ion sensor 7, and a pH sensor 8. The liquid level sensor 6, fluoride ion sensor 7, and pH sensor 8 are all electrically connected to the controller, and respectively collect the liquid level signal, fluoride ion concentration signal, and pH value signal inside the sector-shaped cavity 4 and feed them back to the controller.

[0026] Each of the fan-shaped cavities 4 has a drain pipe 16 in the lower middle part of its side wall and a mud discharge pipe 17 at the bottom. A drain solenoid valve and a mud discharge solenoid valve are respectively installed on the drain pipe 16 and the mud discharge pipe 17. Both the drain solenoid valve and the mud discharge solenoid valve are electrically connected to the controller.

[0027] It also includes a blower 9, whose outlet pipe is connected to a main pipe. The main pipe is connected to a first branch and a second branch. The first branch is connected to the inlet of a venturi tube 10, and the outlet of the venturi tube 10 is connected to multiple drug delivery pipelines 11. Each drug delivery pipeline 11 is equipped with a drug delivery solenoid valve, and the ends of the multiple drug delivery pipelines 11 are respectively connected to the front end of the aeration pipe 15 of the corresponding sector cavity 4. The second branch connects to multiple air delivery pipelines 14, and the ends of the multiple air delivery pipelines 14 are respectively connected to the front end of the aeration pipe 15 of the corresponding sector cavity 4. At this time, a suction tube is installed at the throat of the Venturi tube 10. The suction tube is connected to the calcium solution storage tank 18, acid solution storage tank 19, alkali solution storage tank 20, PAC agent storage tank 21, and PAM agent storage tank 22 through multiple independent suction branches. Solenoid valves for the agent storage tanks and flow meters are installed sequentially on each suction branch. A gas delivery solenoid valve is installed on the gas delivery pipeline 14, and a proportional solenoid valve 13 is installed at the front end of the aeration pipe 15. Each flow meter, agent storage tank solenoid valve, drug delivery solenoid valve, gas delivery solenoid valve, and proportional solenoid valve 13 are electrically connected to the controller.

[0028] When the liquid level sensor 6 in the sector cavity 4 detects the set liquid level, the controller closes the corresponding water distribution pipe solenoid valve to stop water intake; entering the calcium salt reaction stage, the controller calculates the required calcium solution dosage based on the initial fluoride ion concentration signal fed back by the fluoride ion sensor 7, closes the gas delivery solenoid valve on the gas delivery pipeline 14, and opens the drug delivery solenoid valve on the drug delivery pipeline 11 and the drug storage tank solenoid valve on the corresponding liquid suction branch of the calcium solution storage tank 18. The airflow provided by the blower 9 generates negative pressure through the throat of the venturi tube 10, drawing in the calcium solution and carrying it through the drug delivery pipeline 11. The aeration pipe 15 is inserted into the fan-shaped cavity 4, and the aeration intensity is adjusted to the required flow rate for stirring through the proportional solenoid valve 13, so that the calcium solution and the fluoride-containing wastewater are fully mixed and reacted. When the cumulative flow rate fed back by the flow meter reaches the preset dosage, the controller closes the solenoid valve of the corresponding reagent storage tank and the delivery solenoid valve of the calcium solution storage tank 18, and ends the calcium solution addition. After the calcium salt reaction has gone through the preset reaction time, the fluoride ion sensor 7 detects the current fluoride ion concentration again. If it has not dropped to the preset threshold, calcium solution is added again in the above manner until the fluoride ion concentration reaches the standard, and the calcium salt reaction ends.

[0029] After the calcium salt reaction is completed, the pH adjustment stage begins. The controller calculates the required dosage of acid or alkali based on the current pH signal fed back by the pH sensor 8, and opens the corresponding solenoid valves of the acid storage tank 19 or alkali storage tank 20 to add acid or alkali into the sector cavity 4. At the same time, the proportional solenoid valve 13 maintains stirring and aeration. When the cumulative flow rate fed back by the flow meter reaches the preset dosage, the controller closes the corresponding solenoid valves of the storage tank and the delivery solenoid valve, ending the pH adjustment dosing. After the preset reaction time, the pH sensor 8 detects the current pH value again. If the preset flocculation reaction range has not been reached, acid or alkali is added again in the above manner until the pH value reaches the target.

[0030] After pH adjustment, the flocculation reaction stage begins. Based on the current fluoride ion concentration signal fed back by the fluoride ion sensor 7, the controller calculates the required dosage of PAC and PAM, closes the gas delivery solenoid valve on the gas delivery pipeline 14, opens the drug delivery solenoid valve on the drug delivery pipeline 11, and sequentially opens the corresponding drug storage tank solenoid valves of PAC drug storage tank 21 and PAM drug storage tank 22. The flocculant and coagulant aid are then delivered into the sector cavity 4 via the Venturi tube 10 with the airflow. At the same time, the controller adjusts the corresponding proportional solenoid valve 13 to reduce the aeration rate to the flocculation micro-disturbance threshold. When the cumulative flow rate fed back by the flow meter reaches the preset dosage, the controller closes the drug delivery solenoid valve and all drug storage tank solenoid valves, stops the drug delivery, and maintains micro-disturbance aeration to allow the flocs to grow fully. After the preset reaction time for flocculation, the controller closes the gas delivery solenoid valve on the gas delivery pipeline 14, stops aeration, and enters the static sedimentation stage.

[0031] After settling, the controller opens the drain solenoid valve corresponding to the sector cavity 4 to discharge the supernatant and collect it for transport to the flotation device (not shown in the figure) for flotation and sludge removal. After the drainage is completed, the sludge discharge solenoid valve is opened to discharge the sludge. After the sludge discharge is completed, the controller switches the water distribution pipe solenoid valve corresponding to the sector cavity 4 to refill the water supply and enter the next processing cycle.

[0032] Multiple sector cavities 4 operate alternately with staggered phases under the timing control of the controller, enabling the entire device to continuously receive fluoride-containing wastewater and output the treated supernatant.

[0033] Example 2 Based on Example 1, this embodiment improves the design of the aeration pipe 15 inside the fan-shaped cavity 4. The remaining structures, connections, and control procedures are completely consistent with Example 1, and will not be repeated here.

[0034] In this embodiment, the aeration pipe 15 adopts a segmented combination structure, which is composed of a connecting pipe 12 that runs through the top of the box 1 and a spiral pipe 23 located at the bottom of the connecting pipe. The connecting pipe 12 and the spiral pipe 23 are an integral connected structure, and the airflow and the drug mixture can flow smoothly throughout the pipe.

[0035] The connecting pipe 12 is connected to the end interface of the fixed gas pipeline 14 and the drug pipeline 11, serving as the main inlet section for gas and drug inlet, and is used to transport high-pressure gas flow and gas-drug mixture to the bottom area of ​​the chamber. The connecting pipe 12 adopts a rigid pipe structure to ensure stable gas and drug delivery pressure and avoid pipeline deformation and airflow deviation.

[0036] The spiral tube 23 is suspended in the lower part of the inner cavity of the fan-shaped cavity 4, maintaining a distance of 10-15cm from the bottom surface of the fan-shaped cavity 4. The spiral tube 23 adopts a spiral winding structure that gradually expands from the inside to the outside. Several aeration nozzles 24 are evenly installed on the tube body of the spiral tube 23. The aeration nozzles 24 are arranged obliquely downward or laterally, which can achieve uniform and fine aeration from the middle layer to the bottom layer of the water.

[0037] Under intense stirring conditions involving calcium salt reaction and pH adjustment, high-pressure airflow is directionally injected through multiple spirally arranged aeration nozzles (24). The airflow impacts the bottom water at an angle, and the spirally arranged piping structure creates a vortex stirring phenomenon within the chamber. This vortex flow rapidly agitates all the water within the chamber, eliminating dead zones at the bottom and ensuring rapid and uniform mixing of the added calcium salts, acid / alkali reagents, and fluoride-containing wastewater. This improves the reaction rate and uniformity, avoiding defects such as localized low reagent concentrations and incomplete reactions.

[0038] Under the micro-disturbance condition of flocculation reaction, the air flow rate in the pipeline is reduced by the proportional solenoid valve 13, and the aeration nozzle 24 on the spiral tube 23 can output a gentle microbubble flow. While ensuring slight disturbance of the water body and preventing the sedimentation and accumulation of flocculants, it will not produce violent water flow impact, effectively protect the already generated calcium fluoride floc structure, avoid the problems of floc breakage and difficulty in sedimentation of fine particles, and improve the water quality of subsequent sedimentation effluent.

[0039] Compared to the traditional bottom-fitting straight pipe aeration structure, the combined aeration pipe 15 used in this embodiment not only avoids the problems of bottom sediment clogging the aeration points and silting up the pipeline, but also forms a vortex through spiral aeration, which can adapt to the stirring and disturbance requirements of different stages of the defluorination process. The structure is simple, has good anti-clogging properties, and improves the defluorination stability and treatment efficiency of the whole set of equipment.

[0040] Example 3 After calcium salt precipitation and flocculation, calcium fluoride sludge and a small amount of flocculent residue will gradually accumulate at the bottom of sector 4 of the fluoride-containing wastewater. Even after the normal drainage and sludge removal process, some unremoved sludge may remain at the bottom of the chamber, potentially negatively impacting the reaction efficiency of the next batch. Therefore, it is necessary to clean the bottom of each sector 4 after normal treatment cycles. This embodiment utilizes only the existing water distribution pipe 5, aeration pipe 15, and sludge discharge pipe 17, and completes the process through the timing control of the controller.

[0041] Specifically, the wastewater in the water collection and regulating tank 2 naturally separates into layers after settling, with the upper part being the supernatant and the bottom part being the sediment. The inlet of the water distribution pipe 5 is located in the upper part of the water collection and regulating tank 2, so that the water entering the water distribution pipe 5 is mainly the supernatant with a low suspended solids content.

[0042] After a sector 4 has completed drainage and sludge removal, the controller performs the following cleaning operation: (1) The controller controls the pulse opening and closing of the solenoid valve of the water distribution pipe corresponding to the sector cavity 4. Each time it is opened, the supernatant in the upper part of the water collection regulating tank 2 enters the water distribution pipe 5. The outlet height of the water distribution pipe 5 is located in the upper part of the sector cavity 4. In this way, the supernatant will fall to the bottom of the sector cavity 4 under the action of gravity, thereby breaking up some of the sludge remaining at the bottom.

[0043] (2) During the interval of pulse water inlet, the controller opens the gas supply solenoid valve and adjusts the proportional solenoid valve 13 to the maximum opening, so that the high pressure airflow is sprayed out from the aeration nozzle 24 through the aeration pipe 15 to perform short-term intense aeration on the water in the chamber, further stirring up the dispersed sludge and suspending it in the supernatant. Then the aeration is turned off, and the sludge-containing wastewater is discharged through the sludge discharge pipe 17.

[0044] (3) Repeat the above pulse water intake and intermittent aeration steps multiple times until the residual sludge at the bottom of the fan-shaped cavity 4 is carried away one by one.

[0045] The above process completes the dispersal of bottom sediment, suspension of sludge, and discharge of muddy wastewater. The muddy wastewater generated during cleaning is then allowed to settle before being transported back to the collection and equalization tank 2. The entire cleaning process requires no additional cleaning pumps, cleaning pipelines, or external clean water sources.

[0046] Working principle: During operation, fluoride-containing wastewater first enters the water collection and regulating tank 2. The controller opens the solenoid valve of the water distribution pipe of the corresponding idle sector 4 according to the operating status of each sector 4. The wastewater flows into the sector 4 by gravity through the water distribution pipe 5 due to the liquid level difference. When the liquid level sensor 6 detects the set liquid level, the controller closes the solenoid valve of the water distribution pipe and stops the water intake.

[0047] The calcium salt reaction stage then begins. Based on the initial fluoride ion concentration signal fed back by the fluoride ion sensor 7, the controller calculates the required calcium solution dosage, closes the gas delivery solenoid valve on the gas delivery pipeline 14, and opens the drug delivery solenoid valve on the drug delivery pipeline 11 and the drug storage tank solenoid valve on the corresponding suction branch of the calcium solution storage tank 18. The airflow provided by the blower 9 generates negative pressure at the throat of the venturi tube 10, drawing the calcium solution and sending it into the sector cavity 4 along with the airflow through the drug delivery pipeline 11 and the aeration pipe 15. At the same time, the aeration intensity is adjusted to the required flow rate for stirring by the proportional solenoid valve 13, ensuring that the calcium solution and the fluoride-containing wastewater are fully mixed and reacted. When the cumulative flow rate fed back by the flow meter reaches the preset dosage, the controller closes the corresponding drug storage tank solenoid valve and the drug delivery solenoid valve of the calcium solution storage tank 18, ending the calcium solution addition. After the preset reaction time, the fluoride ion sensor 7 detects the current fluoride ion concentration again. If it has not dropped to the preset threshold, calcium solution is added again in the above manner until the fluoride ion concentration reaches the standard, ending the calcium salt reaction.

[0048] After the calcium salt reaction is completed, the pH adjustment stage begins. The controller calculates the required dosage of acid or alkali based on the current pH signal fed back by the pH sensor 8, and opens the corresponding solenoid valves of the acid storage tank 19 or alkali storage tank 20 to add acid or alkali into the sector cavity 4. At the same time, the proportional solenoid valve 13 maintains stirring and aeration. When the cumulative flow rate fed back by the flow meter reaches the preset dosage, the controller closes the corresponding solenoid valves of the storage tank and the delivery solenoid valve, ending the pH adjustment dosing. After the preset reaction time, the pH sensor 8 detects the current pH value again. If the preset flocculation reaction range has not been reached, acid or alkali is added again in the above manner until the pH value reaches the target.

[0049] After pH adjustment, the flocculation reaction stage begins. Based on the current fluoride ion concentration signal fed back by the fluoride ion sensor 7, the controller calculates the required dosage of PAC and PAM, closes the gas delivery solenoid valve on the gas delivery pipeline 14, opens the drug delivery solenoid valve on the drug delivery pipeline 11, and sequentially opens the corresponding drug storage tank solenoid valves of PAC drug storage tank 21 and PAM drug storage tank 22. The flocculant and coagulant aid are then delivered into the sector cavity 4 via the Venturi tube 10 with the airflow. At the same time, the controller adjusts the corresponding proportional solenoid valve 13 to reduce the aeration rate to the flocculation micro-disturbance threshold. When the cumulative flow rate fed back by the flow meter reaches the preset dosage, the controller closes the drug delivery solenoid valve and all drug storage tank solenoid valves, stops the drug delivery, and maintains micro-disturbance aeration to allow the flocs to grow fully. After the preset reaction time for flocculation, the controller closes the gas delivery solenoid valve on the gas delivery pipeline 14, stops aeration, and enters the static sedimentation stage.

[0050] After settling, the controller opens the drain solenoid valve corresponding to the sector cavity 4 to discharge the supernatant and collect it for transport to the flotation device for flotation and sludge removal. After the drainage is completed, the sludge discharge solenoid valve is opened to discharge the sludge. After the sludge discharge is completed, the controller switches the water distribution pipe solenoid valve corresponding to the sector cavity 4 to allow water to re-enter and enter the next processing cycle.

[0051] Multiple sector cavities 4 operate alternately in staggered phases under the timing control of the controller: when the first sector cavity 4 enters the calcium salt reaction stage, the second sector cavity 4 begins to receive water; when the first sector cavity 4 enters the pH adjustment stage, the second sector cavity 4 enters the calcium salt reaction stage, and the third sector cavity 4 begins to receive water; and so on, with each sector cavity 4 starting one process step behind the others, so that at any given time, a sector cavity 4 is in the water intake, reaction, sedimentation, or drainage stage, thereby achieving continuous reception of fluoride-containing wastewater and output of treated supernatant.

[0052] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. An integrated device for defluoridation of fluoride-containing wastewater, characterized in that, Includes a housing (1) and a water collection and regulating tank (2) fixed in the housing (1), the water collection and regulating tank (2) being used to collect fluoride-containing wastewater to be treated; The interior of the box (1) is divided into multiple independent sector-shaped cavities (4) by multiple partitions (3). Each sector-shaped cavity (4) is an independent reaction unit that integrates calcium salt reaction, pH adjustment and flocculation reaction. Each sector-shaped cavity (4) can independently complete all the above reaction processes. The water collection regulating tank (2) is equipped with multiple water distribution pipes (5) that are connected to the sector cavity (4) one by one. Each water distribution pipe (5) is equipped with an inlet valve controlled by the controller. The controller independently controls the water inlet sequence of each sector cavity (4) by switching the on and off of each inlet valve. Each of the fan-shaped cavities (4) is provided with a stirring device, a drain pipe (16) and a mud discharge pipe (17), and a drain valve and a mud discharge valve controlled by the controller are respectively installed at the drain pipe (16) and the mud discharge pipe (17); The controller has a preset timing control program for each sector cavity (4). Each sector cavity (4) is in a different reaction stage at the same time point, and the start-up time interval of adjacent sector cavities is equal. At any given time, at least one sector cavity is in the water inlet stage, at least one sector cavity is in the chemical dosing reaction stage, and at least one sector cavity is in the sedimentation or drainage stage. Under the timing control of the controller, each sector cavity operates alternately with staggered phases to achieve continuous inlet and outlet water treatment of fluoride-containing wastewater.

2. The integrated device for defluoridation of fluoride-containing wastewater according to claim 1, characterized in that: The box (1) is a cylindrical structure. The water collection and regulating groove (2) is fixed at the center of the box (1). Multiple partitions (3) are arranged in a ring array and are fixedly connected between the inner wall of the box (1) and the outer wall of the water collection and regulating groove (2), dividing the interior of the box (1) into multiple fan-shaped cavities (4).

3. The integrated device for defluoridation of fluoride-containing wastewater according to claim 1, characterized in that: The stirring device is an aeration pipe (15), which is set inside each sector cavity (4) to supply air to the inside of the sector cavity (4) to realize the stirring of calcium salt reaction, the stirring of pH adjustment and the micro-disturbance of the flocculation stage.

4. The integrated device for defluoridation of fluoride-containing wastewater according to claim 3, characterized in that: It also includes a blower (9); the outlet of the blower (9) is connected to a main pipe, which is connected to a first branch and a second branch respectively; the first branch is connected to a venturi tube (10), the outlet of the venturi tube (10) is connected to multiple drug delivery pipelines (11), and a drug delivery solenoid valve controlled by the controller is installed on the drug delivery pipelines (11); a suction tube is installed at the throat of the venturi tube (10), and the suction tube is connected to a calcium solution storage tank, an acid solution storage tank, and an alkali solution storage tank respectively through multiple suction branches. The PAC and PAM drug storage tanks are equipped with drug storage tank solenoid valves and flow meters controlled by the controller on each liquid absorption branch; the second branch is connected to multiple gas transmission pipelines (14), and gas transmission solenoid valves controlled by the controller are installed on the gas transmission pipelines (14); the controller controls the opening and closing of the drug transmission solenoid valve and the gas transmission solenoid valve, opens the drug transmission solenoid valve and closes the gas transmission solenoid valve during the drug addition stage, and closes the drug transmission solenoid valve and opens the gas transmission solenoid valve during the stirring stage.

5. The integrated device for defluoridation of fluoride-containing wastewater according to claim 4, characterized in that: Each of the aeration pipes (15) is equipped with a proportional solenoid valve (13) controlled by the controller. The controller adjusts the opening of the proportional solenoid valve (13) according to different reaction stages, providing strong aeration intensity in the calcium salt reaction, medium aeration intensity in the pH adjustment stage, and weak aeration intensity in the flocculation stage.

6. The integrated device for defluoridation of fluoride-containing wastewater according to claim 4, characterized in that: Each of the sector-shaped cavities (4) is also equipped with a liquid level sensor (6), a fluoride ion sensor (7), and a pH sensor (8). All three are electrically connected to the controller and are used to collect the liquid level, fluoride ion concentration, and pH value signals in each sector-shaped cavity (4) and feed them back to the controller. The controller determines the theoretical total amount of chemicals to be added for this batch of reaction based on the initial concentration signal fed back by the fluoride ion sensor (7) during the water inlet stage. After the reaction is completed, the controller reads the feedback value of the fluoride ion sensor (7) or the pH sensor (8) again. If the preset threshold is not reached, supplementary addition is initiated.

7. The integrated device for defluoridation of fluoride-containing wastewater according to claim 3, characterized in that: The aeration pipe (15) adopts a segmented combination structure, including a connecting pipe (12) that runs through the top of the box (1) and a spiral pipe (23) set at the bottom of the connecting pipe (12). The connecting pipe (12) and the spiral pipe (23) are an integral connected structure. The spiral pipe (23) is suspended in the lower part of the inner cavity of the fan-shaped cavity (4) and maintains a predetermined distance from the bottom surface of the fan-shaped cavity (4).

8. The integrated device for defluoridation of fluoride-containing wastewater according to claim 7, characterized in that: The spiral tube (23) adopts a spiral winding structure that gradually expands from the inside to the outside. Multiple aeration nozzles (24) are evenly installed on the tube body of the spiral tube (23). The aeration nozzles (24) are arranged obliquely downward or laterally.

9. The integrated device for defluoridation of fluoride-containing wastewater according to claim 1, characterized in that: The upper end of the water distribution pipe (5) is higher than the top surface of the box (1), and the wastewater in the water collection and regulating tank (2) flows into each of the sector cavities (4) by gravity due to the liquid level difference.

10. An integrated device for defluoridation of fluoride-containing wastewater according to claim 4, characterized in that: The controller is also pre-programmed with a cleaning control program. When one of the sector chambers (4) has completed drainage and sludge removal, the controller executes the cleaning control program, controls the solenoid valve of the water distribution pipe corresponding to the sector chamber (4) to open in a pulse manner, and controls the solenoid valve of the air supply corresponding to the sector chamber (4) to open during the pulse interval, so that the supernatant from the water collection regulating tank (2) and the high-pressure airflow from the blower (9) alternately enter the sector chamber (4) in a time-sharing manner, stirring up the residue deposited at the bottom of the sector chamber (4) and discharging it through the sludge discharge pipe (17).

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