A special equipment for removing fluorides

Abstract

This invention relates to the field of fluoride removal technology, and in particular to a dedicated fluoride removal device, comprising a pH adjustment and dosing device, a calcium chloride dosing device, a fluoride decomposing agent dosing device, multiple water pumps, a mixer, a pH and fluoride ion detection device, a sludge discharge pump, an inclined plate, a scraper, a data acquisition unit, an analysis unit, and a control unit. The first analysis unit determines the wastewater treatment method, the second analysis unit determines the method of adding calcium chloride and the dosing cycle of the fluoride decomposing agent, and determines whether to discharge the treated wastewater into the corresponding sedimentation tank. The control unit controls the equipment to perform fluoride removal treatment based on the analysis results. This invention overcomes the problems of the existing technology, which has a single wastewater treatment method and poor accuracy in controlling the wastewater fluoride removal process.

Description

Technical Field

[0001] This invention relates to the field of fluoride removal technology, and in particular to a special device for fluoride removal. Background Technology

[0002] Wastewater generated in industries such as new materials, new energy batteries, metallurgy, and chemicals contains high concentrations of fluoride ions. If improperly treated, these fluoride ions can flow into water bodies, polluting them and harming human health. The harmful effects of fluoride ions on the human body include: primarily damaging bones, causing limb movement disorders, and in severe cases, osteoporosis or deformities, leading to increased susceptibility to spontaneous fractures; secondly, making teeth brittle and prone to spots; and damaging the skin, causing pain, eczema, and various types of dermatitis. Currently, the main method for treating fluoride ions is to utilize the reaction of fluoride ions with certain substances, causing them to precipitate as insoluble compounds, thus achieving the effect of removing fluoride ions. The most commonly used chemicals for removing fluoride ions include calcium chloride and highly effective fluoride chelating agents. Calcium ions and fluoride ions can combine to form insoluble calcium fluoride, removing fluoride ions from the water. Calcium chloride is relatively inexpensive, but its removal efficiency is low. When the fluoride ion concentration is low, the removal efficiency of calcium chloride drops significantly, making it difficult to meet emission requirements and requiring large amounts of calcium chloride. High-efficiency fluoride chelating agents, on the other hand, have high removal efficiency, but are expensive. Using only high-efficiency fluoride chelating agents results in high costs. Common fluoride ion removal processes simply involve adding calcium chloride or high-efficiency fluoride chelating agents to the treatment tank based on calculations. However, this may not achieve optimal fluoride ion removal, leading to insufficient or excessive dosage and waste, thus reducing economic efficiency.

[0003] Chinese Patent Publication No. CN104591363B discloses an integrated water purification device for removing fluoride from water, comprising an inlet unit, a defluorination reaction unit, a floc separation and reflux unit, and a filtration unit connected in sequence; the inlet unit and the floc separation and reflux unit are connected by a reflux pipe, and a first baffle and a second baffle are respectively arranged vertically between the defluorination reaction unit and the floc separation and reflux unit, and between the floc separation and reflux unit and the filtration unit; the defluorination reaction unit adopts a downward flow, and its bottom is provided with an outlet with a height of 10-150cm, and a first baffle is provided at a distance d on the outside of the outlet, where d≥3cm; the floc separation and reflux unit is located between the first baffle, the second baffle and the bottom plate, and an inclined plate is provided between the second baffle and the bottom plate, with an inclination angle of 20°-45°; the distance between the first baffle and the second baffle is greater than or equal to d, and the inclination angle of the line connecting the top of the second baffle (31) and the top of the first baffle is 10°-75°.

[0004] It is evident that existing technologies have the following problems: due to the single method of wastewater treatment during the defluorination process and the poor precision in controlling the wastewater defluorination process, the cost of defluorination is too high and the efficiency is low. Summary of the Invention

[0005] Therefore, the present invention provides a special equipment for defluorination, which overcomes the problems of the existing technology in the single method of wastewater treatment during the defluorination process and the poor accuracy of the control of the wastewater defluorination process.

[0006] To achieve the above objectives, the present invention provides a dedicated device for fluoride removal, comprising:

[0007] The dosing unit includes a pH adjustment dosing device connected to the water collection tank, a calcium chloride dosing device connected to the calcium chloride reaction tank, and a defluoridation complexing agent dosing device connected to the defluoridation complexing agent reaction tank.

[0008] The stirring unit includes a first stirrer disposed above the calcium chloride reaction tank and a second stirrer disposed above the defluorination complexing agent reaction tank;

[0009] The detection unit includes a pH detection device and a first fluoride ion detection device installed in the water collection tank, a second fluoride ion detection device installed in the calcium chloride reaction tank, a third fluoride ion detection device installed in the defluoridation complexing agent reaction tank, and a fourth fluoride ion detection device installed in the effluent storage tank.

[0010] The data acquisition unit is connected to the pH detection device, the first fluoride ion detection device, the second fluoride ion detection device, the third fluoride ion detection device, and the fourth fluoride ion detection device, respectively, to acquire the acidity and alkalinity of the wastewater in the collection tank, the concentration of the first fluoride ion in the wastewater in the collection tank, the concentration of the second fluoride ion in the wastewater in the calcium chloride reaction tank, the concentration of the third fluoride ion in the wastewater in the defluorination complexing agent reaction tank, and the concentration of the fourth fluoride ion in the wastewater in the effluent storage tank.

[0011] The first analysis unit, which is connected to the data acquisition unit, is used to determine the treatment method of the wastewater based on the first fluoride ion concentration in the wastewater collection tank.

[0012] Alternatively, the wastewater treatment method may be determined based on the wastewater status evaluation value of the wastewater in the collection tank;

[0013] Alternatively, the wastewater treatment method may be determined based on the relative difference between the pH of the wastewater in the collection tank and the first preset pH.

[0014] The second analysis unit, which is connected to the data acquisition unit, determines the method of adding calcium chloride to the calcium chloride reaction tank based on the second fluoride ion concentration in the wastewater in the calcium chloride reaction tank, determines whether to discharge the wastewater in the calcium chloride reaction tank into the calcium chloride precipitation tank based on the second fluoride ion concentration in the wastewater in the calcium chloride reaction tank, determines the addition cycle of the defluorination complexing agent, and determines whether to discharge the wastewater in the defluorination complexing agent reaction tank into the defluorination complexing agent precipitation tank based on the third fluoride ion concentration in the wastewater in the defluorination complexing agent reaction tank.

[0015] The decision to discharge the wastewater from the effluent storage tank into the collection tank is based on the concentration of tetrafluoride ions in the wastewater in the effluent storage tank.

[0016] The control unit is connected to the first analysis unit and the second analysis unit respectively, and is used to control the equipment to remove fluoride based on the analysis results of the first analysis unit and the second analysis unit.

[0017] Furthermore, the first analysis unit determines to treat the wastewater using a first treatment method based on the comparison result that the first fluoride ion concentration in the wastewater in the collection tank is less than the first preset fluoride ion concentration. The first treatment method is to discharge the wastewater in the collection tank into the defluorination complexing agent reaction tank for defluorination.

[0018] Furthermore, the first analysis unit determines to treat the wastewater using a second treatment method based on the comparison result that the first fluoride ion concentration in the wastewater in the collection tank is greater than the second preset fluoride ion concentration. The second treatment method is to discharge the wastewater in the collection tank into a calcium chloride reaction tank for fluoride removal.

[0019] Furthermore, the first analysis unit determines the wastewater for the first time based on the comparison result that the first fluoride ion concentration in the wastewater in the collection tank is greater than or equal to the first preset fluoride ion concentration and less than or equal to the second preset fluoride ion concentration. Based on the comparison result that the wastewater state evaluation value in the collection tank is greater than the second preset wastewater state evaluation value, the unit determines the wastewater to be treated in the second treatment method. Based on the comparison result that the wastewater state evaluation value is greater than or equal to the first preset wastewater state evaluation value and less than or equal to the second preset wastewater state evaluation value, the unit determines the wastewater to be treated in the first treatment method.

[0020] Furthermore, the first analysis unit determines to perform a second judgment on the wastewater based on the comparison result that the wastewater state evaluation value is less than the first preset wastewater state evaluation value, and determines to treat the wastewater in a first treatment method based on the comparison result that the relative difference is less than or equal to the first preset relative difference, and determines to treat the wastewater in a second treatment method based on the comparison result that the relative difference is greater than the first preset relative difference.

[0021] Furthermore, the first analysis unit calculates the wastewater state evaluation value according to the following formula, and sets it as follows:

[0022]

[0023] Where P represents the wastewater status evaluation value, S represents the pH of the wastewater in the collection tank, and A represents the concentration of the first fluoride ion.

[0024] Furthermore, the second analysis unit determines to add calcium chloride to the calcium chloride reaction tank in a first addition method based on the comparison result that the second fluoride ion concentration in the wastewater in the calcium chloride reaction tank is less than or equal to the third preset fluoride ion concentration. The first addition method is to add calcium chloride intermittently for a first preset time period.

[0025] Based on the comparison result that the second fluoride ion concentration is greater than the third preset fluoride ion concentration, it is determined that calcium chloride is added to the calcium chloride reaction tank in a second addition method, which is to add calcium chloride intermittently for a second preset time period.

[0026] Furthermore, the second analysis unit calculates the addition cycle of the defluorination complexing agent according to the following formula and sets it as follows:

[0027]

[0028] Where Tt represents the addition cycle, and C represents the concentration of tertiary fluoride ions in the wastewater in the defluorination complexing agent reaction tank.

[0029] Furthermore, the second analysis unit determines, based on the comparison result that the second fluoride ion concentration in the wastewater of the calcium chloride reaction tank is less than or equal to the first preset fluoride ion concentration, to discharge the wastewater in the calcium chloride reaction tank into the calcium chloride precipitation tank.

[0030] Based on the comparison results of the third fluoride ion concentration in the wastewater of the defluorination complexing agent reaction tank being less than or equal to the fourth preset fluoride ion concentration, it is determined that the wastewater in the defluorination complexing agent reaction tank will be discharged into the defluorination complexing agent sedimentation tank.

[0031] Furthermore, the second analysis unit determines, based on the comparison result that the fourth fluoride ion concentration of the wastewater in the effluent storage tank is greater than the fifth preset fluoride ion concentration, to discharge the wastewater in the effluent storage tank into the collection tank.

[0032] Compared with the prior art, the beneficial effect of the present invention is that the present invention determines the treatment method of the wastewater based on the comparison between the first fluoride ion concentration and the preset fluoride ion concentration in the wastewater collection tank. When the fluoride ion concentration is too high, calcium chloride is used for fluoride removal, and when the fluoride ion concentration is too low, a fluoride decomposing agent is used for fluoride removal. This allows for precise selection of the appropriate treatment method, improves the efficiency of fluoride removal, saves on reagent costs, and avoids waste.

[0033] Furthermore, the present invention adjusts the pH of the wastewater to a suitable pH for the specific treatment method in advance, which helps to improve the defluorination effect and avoid waste of reagents.

[0034] Furthermore, this invention determines the wastewater treatment method based on the comparison between the wastewater state evaluation value in the collection tank and the preset wastewater state evaluation value. When it is impossible to accurately determine which treatment method to use based solely on the fluoride ion concentration, the treatment method is precisely selected based on the wastewater state evaluation value. When the acidity or alkalinity of the wastewater is neutral or slightly alkaline and the fluoride ion concentration is relatively high, the second treatment method is used. When the acidity or alkalinity of the wastewater is near neutral and the fluoride ion concentration is relatively low, the first treatment method is used to efficiently remove fluoride and save on reagent usage costs.

[0035] Furthermore, the present invention accurately assesses the state of wastewater by measuring its pH and first fluoride ion concentration in the collection tank to help determine the appropriate treatment method for the wastewater.

[0036] Furthermore, the present invention determines the treatment method of the wastewater based on the comparison result between the relative difference and the first preset relative difference, so as to further determine the appropriate treatment method when the wastewater is alkaline but the fluoride ion concentration is relatively high, so as to improve the defluorination efficiency more accurately and reduce the cost of reagent use.

[0037] Furthermore, this invention determines the method of adding calcium chloride to the calcium chloride reaction tank based on the comparison between the second fluoride ion concentration and the third preset fluoride ion concentration in the wastewater of the calcium chloride reaction tank, ensuring that the defluorination reaction occurs fully, avoiding waste caused by excessive addition of calcium chloride, and saving defluorination time and improving efficiency.

[0038] Furthermore, the present invention determines whether to discharge the wastewater in the calcium chloride reaction tank into the calcium chloride precipitation tank based on the comparison between the second fluoride ion concentration and the first preset fluoride ion concentration in the wastewater in the calcium chloride reaction tank, thereby accurately determining whether the calcium chloride defluorination is completed and proceeding to the next precipitation step.

[0039] Furthermore, this invention precisely calculates the addition cycle of the defluorination complexing agent based on the concentration of tert-fluoride ions in the wastewater in the defluorination complexing agent reaction tank, accurately controls the conditional rate of the defluorination complexing agent, ensures the full occurrence of the defluorination reaction, and avoids waste caused by excessive addition of the agent.

[0040] Furthermore, the present invention determines whether to discharge the wastewater in the defluorination complexing agent reaction tank into the defluorination complexing agent sedimentation tank based on the comparison result of the third fluoride ion concentration and the fourth preset fluoride ion concentration in the wastewater in the defluorination complexing agent reaction tank, so as to accurately determine whether the defluorination of the defluorination complexing agent is completed and proceed to the next step of sedimentation.

[0041] Furthermore, the present invention determines whether to discharge the wastewater in the effluent storage tank into the collection tank based on the comparison result of the fourth fluoride ion concentration and the fifth preset fluoride ion concentration in the wastewater in the effluent storage tank. Since the precipitate may undergo secondary dissolution during the sedimentation process, resulting in an increase in the fluoride ion concentration, the fluoride ion concentration is detected again so that if the fluoride ion concentration does not meet the standard, the wastewater is returned to the collection tank for treatment. Attached Figure Description

[0042] Figure 1 This is a structural diagram of a dedicated fluoride removal device according to an embodiment of the present invention;

[0043] Figure 2 This is a first cross-sectional view of the fluoride removal equipment according to an embodiment of the present invention;

[0044] Figure 3 This is a second cross-sectional view of the fluoride removal equipment according to an embodiment of the present invention;

[0045] Figure 4 This is a structural block diagram of a dedicated fluoride removal device according to an embodiment of the present invention;

[0046] In the diagram, 1-pH adjustment and dosing device, 2-collection tank, 3-calcium chloride dosing device, 4-calcium chloride reaction tank, 5-fluoride chelating agent dosing device, 6-fluoride chelating agent reaction tank, 7-first water pump, 8-second water pump, 9-third water pump, 10-calcium chloride sedimentation tank, 11-fourth water pump, 12-fifth water pump, 13-fluoride chelating agent sedimentation tank, 14-sixth water pump, 15-effect water storage tank, 16-seventh water pump, 17-first mixer, 18-second mixer, 19-pH detection device, 20-then ... 21-Second fluoride ion detection device, 22-Third fluoride ion detection device, 23-Fourth fluoride ion detection device, 24-First sludge discharge pump, 25-Second sludge discharge pump, 26-First inclined plate, 27-Second inclined plate, 28-First scraper, 29-First drive motor, 30-Second drive motor, 31-First track, 32-First scraper blade, 33-Second scraper, 34-Third drive motor, 35-Fourth drive motor, 36-Second track, 37-Second scraper blade. Detailed Implementation

[0047] To make the objectives and advantages of the present invention clearer, the present invention will be further described below with reference to embodiments; it should be understood that the specific embodiments described herein are merely for explaining the present invention and are not intended to limit the present invention.

[0048] Preferred embodiments of the present invention will now be described with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0049] It should be noted that in the description of this invention, the terms "upper", "lower", "left", "right", "inner", "outer", etc., which indicate directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings. This is only for the convenience of description and is not intended to indicate or imply that the device or element must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of this invention.

[0050] Furthermore, it should be noted that, in the description of this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0051] Please see Figure 1-4 As shown, Figure 1 This is a structural diagram of a dedicated fluoride removal device according to an embodiment of the present invention; Figure 2 This is a first cross-sectional view of the fluoride removal equipment according to an embodiment of the present invention; Figure 3 This is a second cross-sectional view of the fluoride removal equipment according to an embodiment of the present invention; Figure 4 This is a structural block diagram of a dedicated fluoride removal device according to an embodiment of the present invention.

[0052] The fluoride removal equipment in this embodiment of the invention includes:

[0053] pH adjustment dosing device 1 is connected to water collection tank 2 and is used to adjust the acidity or alkalinity of wastewater in the water collection tank.

[0054] The calcium chloride dosing device 3 is connected to the calcium chloride reaction tank 4 and is used to add calcium chloride to the calcium chloride reaction tank to remove fluoride.

[0055] The defluorination complexing agent dosing device 5 is connected to the defluorination complexing agent reaction tank 6 and is used to add defluorination complexing agent to the defluorination complexing agent reaction tank for defluorination.

[0056] The first water pump 7 is connected to the water collection tank and the calcium chloride reaction tank respectively, and is used to discharge the wastewater in the water collection tank into the calcium chloride reaction tank.

[0057] The second water pump 8 is connected to the water collection tank and the defluoridation complexing agent reaction tank respectively, and is used to discharge the wastewater in the water collection tank into the defluoridation complexing agent reaction tank.

[0058] The third water pump 9 is connected to the calcium chloride reaction tank and the calcium chloride sedimentation tank 10 respectively, and is used to discharge the treated wastewater in the calcium chloride reaction tank into the calcium chloride sedimentation tank for sedimentation.

[0059] The fourth water pump 11 is connected to the calcium chloride precipitation tank and the defluoridation complexing agent reaction tank respectively, and is used to discharge the wastewater that has been settled in the calcium chloride precipitation tank into the defluoridation complexing agent reaction tank.

[0060] The fifth water pump 12 is connected to the defluoridation complexing agent reaction tank and the defluoridation complexing agent sedimentation tank 13 respectively, and is used to discharge the treated wastewater in the defluoridation complexing agent reaction tank into the defluoridation complexing agent sedimentation tank for sedimentation.

[0061] The sixth water pump 14 is connected to the defluoridation complexing agent sedimentation tank and the effluent storage tank 15 respectively, and is used to discharge the wastewater that has been settled in the defluoridation complexing agent sedimentation tank into the effluent storage tank.

[0062] The seventh water pump 16 is connected to the effluent storage tank and the collection tank respectively, and is used to discharge the wastewater in the effluent storage tank into the collection tank.

[0063] The first mixer 17 is located above the calcium chloride reaction tank and is used to stir the mixture during the calcium chloride defluorination process.

[0064] The second mixer 18 is located above the defluorination complexing agent reaction tank and is used to stir during the defluorination process of the defluorination complexing agent.

[0065] pH detection device 19 is installed in the water collection tank to detect the acidity / alkalinity S of the wastewater in the water collection tank;

[0066] The first fluoride ion detection device 20 is installed in the water collection tank to detect the concentration A of the first fluoride ion in the wastewater in the water collection tank.

[0067] The second fluoride ion detection device 21 is installed in the calcium chloride reaction tank to detect the concentration of second fluoride ions B in the wastewater of the calcium chloride reaction tank.

[0068] The third fluoride ion detection device 22 is installed in the defluorination complexing agent reaction tank to detect the concentration C of third fluoride ions in the wastewater in the defluorination complexing agent reaction tank.

[0069] The quadratic fluoride ion detection device 23 is installed in the effluent storage tank to detect the quadratic fluoride ion concentration D in the wastewater in the effluent storage tank.

[0070] The first sludge discharge pump 24 is installed above the defluorination complexing agent sedimentation tank to discharge sludge from the defluorination complexing agent sedimentation tank.

[0071] The second sludge discharge pump 25 is installed above the calcium chloride sedimentation tank and is used to discharge sludge from the calcium chloride sedimentation tank.

[0072] The first inclined plate 26 is set in the fluoride removal complexing agent sedimentation tank to promote the sedimentation of suspended solids;

[0073] The second inclined plate 27 is set in the calcium chloride sedimentation tank to promote the sedimentation of suspended solids;

[0074] The first sludge scraper 28 is located below the first inclined plate and consists of a first drive motor 29, a second drive motor 30, a first track 31 and a first scraper 32 mounted on the first track. It is used to discharge sludge from the defluorination complexing agent sedimentation tank to the side near the first sludge discharge pump.

[0075] The second sludge scraper 33 is located below the second inclined plate and consists of a third drive motor 34, a fourth drive motor 35, a second track 36, and a second scraper 37 mounted on the second track. It is used to discharge sludge from the calcium chloride sedimentation tank to the side near the second sludge discharge pump.

[0076] The data acquisition unit is connected to the pH detection device, the first fluoride ion detection device, the second fluoride ion detection device, the third fluoride ion detection device, and the fourth fluoride ion detection device, respectively, to acquire the pH value S of the wastewater in the collection tank, the first fluoride ion concentration A of the wastewater in the collection tank, the second fluoride ion concentration B of the wastewater in the calcium chloride reaction tank, the third fluoride ion concentration C of the wastewater in the defluorination complexing agent reaction tank, and the fourth fluoride ion concentration D of the wastewater in the effluent storage tank.

[0077] The first analysis unit, which is connected to the data acquisition unit, is used to determine the treatment method of the wastewater based on the first fluoride ion concentration A of the wastewater in the collection tank.

[0078] Alternatively, the wastewater treatment method may be determined based on the wastewater status evaluation value P of the wastewater in the collection tank;

[0079] Alternatively, the wastewater treatment method can be determined based on the relative difference ΔS between the pH S of the wastewater in the collection tank and the first preset pH S1.

[0080] The second analysis unit, which is connected to the data acquisition unit, determines the method of adding calcium chloride to the calcium chloride reaction tank based on the second fluoride ion concentration B in the wastewater in the calcium chloride reaction tank, determines whether to discharge the wastewater in the calcium chloride reaction tank into the calcium chloride precipitation tank based on the second fluoride ion concentration B in the wastewater in the calcium chloride reaction tank, determines the addition cycle Tt of the defluorination complexing agent, and determines whether to discharge the wastewater in the defluorination complexing agent reaction tank into the defluorination complexing agent precipitation tank based on the third fluoride ion concentration C in the defluorination complexing agent reaction tank.

[0081] The concentration D of the fourth fluoride ion in the wastewater in the effluent storage tank determines whether the wastewater in the effluent storage tank should be discharged into the collection tank.

[0082] The control unit is connected to the first analysis unit and the second analysis unit respectively, and is used to control the equipment to remove fluoride based on the analysis results of the first analysis unit and the second analysis unit.

[0083] In this embodiment of the invention, the pH adjustment dosing device, the calcium chloride dosing device, and the defluorination complexing agent dosing device are preferably BHJY-2×0.5-32 / 2.4-2 dual-tank dual-pump dosing devices;

[0084] The defluorination complexing agent consists of 20% PAM, 20% PVA, 20% polyaluminum chloride, 10% polyaluminum sulfate, 10% ferric sulfate, 10% polyferric sulfate, and 10% calcium chloride.

[0085] Specifically, the first analysis unit determines the wastewater treatment method based on the comparison between the first fluoride ion concentration A and the preset fluoride ion concentration in the wastewater collection tank. The first analysis unit has a first preset fluoride ion concentration A1 and a second preset fluoride ion concentration A2, and A2 > A1.

[0086] If A < A1, then the first analysis unit determines to treat the wastewater using the first treatment method;

[0087] If A1≤A≤A2, then the first analysis unit determines to make an initial judgment on the wastewater;

[0088] If A > A2, then the first analysis unit determines to treat the wastewater using the second treatment method;

[0089] The first treatment method involves discharging the wastewater from the collection tank into a defluorination complexing agent reaction tank for defluorination, while the second treatment method involves discharging the wastewater from the collection tank into a calcium chloride reaction tank for defluorination.

[0090] In this embodiment of the invention, the first preset fluoride ion concentration A1 is 20 ppm and the second preset fluoride ion concentration A2 is 60 ppm. Those skilled in the art can adjust the first preset fluoride ion concentration A1 and the second preset fluoride ion concentration A2 according to specific circumstances.

[0091] Specifically, the present invention determines the wastewater treatment method based on the comparison between the first fluoride ion concentration and the preset fluoride ion concentration in the wastewater collection tank. When the fluoride ion concentration is too high, calcium chloride is used for fluoride removal, and when the fluoride ion concentration is too low, a fluoride complexing agent is used for fluoride removal. This allows for precise selection of the appropriate treatment method, improving the efficiency of fluoride removal, while saving on reagent costs and avoiding waste.

[0092] Specifically, when the first analysis unit determines that the wastewater is to be treated in the first treatment method, it adjusts the pH of the wastewater in the collection tank to the first preset pH S1. When the first analysis unit determines that the wastewater is to be treated in the second treatment method, it adjusts the pH of the wastewater in the collection tank to the second preset pH S2.

[0093] In this embodiment of the invention, the first preset pH value S1 is 4.5 and the second preset pH value S2 is 8.5. Those skilled in the art can adjust the first preset pH value S1 and the second preset pH value S2 according to specific circumstances.

[0094] Specifically, the present invention adjusts the pH of the wastewater to a level suitable for the corresponding treatment method in advance, which helps to improve the defluoridation effect and avoid waste of reagents.

[0095] Specifically, under the condition of initial judgment of wastewater, the first analysis unit determines the treatment method of the wastewater based on the comparison result of the wastewater state evaluation value P in the collection tank and the preset wastewater state evaluation value. The first analysis unit has a first preset wastewater state evaluation value P1 and a second preset wastewater state evaluation value P2, and P1 < P2.

[0096] If P < P1, then the first analysis unit determines to perform a second judgment on the wastewater;

[0097] If P1≤P≤P2, then the first analysis unit determines to treat the wastewater using the first treatment method;

[0098] If P > P2, then the first analysis unit determines to treat the wastewater using the second treatment method;

[0099] In this embodiment of the invention, the first preset wastewater state evaluation value P1 is -2.48, which is obtained when the pH of the wastewater in the collection tank is 6 and the first fluoride ion concentration A is 40 ppm. The second preset wastewater state evaluation value P2 is 2.48, which is obtained when the pH of the wastewater in the collection tank is 7 and the first fluoride ion concentration A is 40 ppm. Those skilled in the art can adjust the first preset wastewater state evaluation value P1 and the second preset wastewater state evaluation value P2 according to specific circumstances.

[0100] Specifically, this invention determines the wastewater treatment method based on the comparison between the wastewater state evaluation value in the collection tank and the preset wastewater state evaluation value. When it is impossible to accurately determine which treatment method to use based solely on the fluoride ion concentration, the treatment method is precisely selected based on the wastewater state evaluation value. When the acidity or alkalinity of the wastewater is neutral or slightly alkaline and the fluoride ion concentration is relatively high, the second treatment method is used. When the acidity or alkalinity of the wastewater is near neutral and the fluoride ion concentration is relatively low, the first treatment method is used to efficiently remove fluoride and save on reagent usage costs.

[0101] Specifically, the first analysis unit calculates the wastewater state evaluation value P according to the following formula, and sets:

[0102]

[0103] Where S represents the pH of the wastewater in the collection tank.

[0104] Specifically, the present invention uses the pH and first fluoride ion concentration of wastewater in the collection tank to accurately assess the state of the wastewater to help determine the appropriate treatment method for the wastewater.

[0105] Specifically, under the condition of determining that the wastewater is to be judged twice, the first analysis unit calculates the relative difference ΔS between the acidity / alkalinity S of the wastewater in the collection tank and the first preset acidity / alkalinity S1, and determines the treatment method of the wastewater based on the comparison result of the relative difference ΔS and the first preset relative difference ΔS0, and sets ΔS = (S-S1) / S1.

[0106] If △S≤△S0, then the first analysis unit determines to treat the wastewater using the first treatment method;

[0107] If △S>△S0, then the first analysis unit determines to treat the wastewater using the second treatment method;

[0108] In this embodiment of the invention, the first preset relative difference ΔS0 is 0.1. The first preset relative difference ΔS0 is obtained when the pH of the wastewater in the collection tank is 5.0. Those skilled in the art can adjust the first preset relative difference ΔS0 according to the specific circumstances.

[0109] Specifically, the present invention determines the treatment method of the wastewater based on the comparison result between the relative difference and the first preset relative difference, so as to further determine the appropriate treatment method when the wastewater is alkaline but the fluoride ion concentration is relatively high, so as to improve the defluorination efficiency more accurately and reduce the cost of reagent use.

[0110] Specifically, under the condition of defluorination in the calcium chloride reaction tank, the second analysis unit determines the method of adding calcium chloride to the calcium chloride reaction tank based on the comparison result of the second fluoride ion concentration B and the third preset fluoride ion concentration B0 in the wastewater in the calcium chloride reaction tank.

[0111] If B≤B0, then the second analysis unit determines to add calcium chloride to the calcium chloride reaction tank in the first addition method;

[0112] If B > B0, then the second analysis unit determines to add calcium chloride to the calcium chloride reaction tank in the second addition method;

[0113] The first addition method involves intermittently adding calcium chloride over a first preset duration T1, while the second addition method involves intermittently adding calcium chloride over a second preset duration T2.

[0114] In this embodiment of the invention, the third preset fluoride ion concentration B0 is 100 ppm, the first preset duration T1 is 1 hour, and the second preset duration T2 is half an hour. Those skilled in the art can adjust the third preset fluoride ion concentration B0, the first preset duration T1, and the second preset duration T2 according to specific circumstances.

[0115] Specifically, this invention determines the method of adding calcium chloride to the calcium chloride reaction tank based on the comparison between the second fluoride ion concentration and the third preset fluoride ion concentration in the wastewater of the calcium chloride reaction tank. This ensures that the defluorination reaction occurs fully, avoids waste caused by excessive addition of calcium chloride, and saves defluorination time while improving efficiency.

[0116] Specifically, under the condition of defluorination in the calcium chloride reaction tank, the second analysis unit determines whether to discharge the wastewater in the calcium chloride reaction tank into the calcium chloride precipitation tank based on the comparison result of the second fluoride ion concentration B and the first preset fluoride ion concentration A1 in the wastewater in the calcium chloride reaction tank.

[0117] If B≤A1, then the second analysis unit determines that the wastewater in the calcium chloride reaction tank should be discharged into the calcium chloride precipitation tank;

[0118] If B > A1, then the second analysis unit determines that the wastewater in the calcium chloride reaction tank should not be discharged into the calcium chloride precipitation tank.

[0119] Specifically, the present invention determines whether to discharge the wastewater in the calcium chloride reaction tank into the calcium chloride precipitation tank based on the comparison between the second fluoride ion concentration and the first preset fluoride ion concentration in the wastewater in the calcium chloride reaction tank, so as to accurately determine whether the defluorination of calcium chloride is completed and proceed to the next step of precipitation.

[0120] Specifically, under the defluorination conditions in the defluorination complexing agent reaction tank, the second analysis unit calculates the addition cycle Tt of the defluorination complexing agent according to the following formula, and sets it as follows:

[0121]

[0122] Where C represents the concentration of third fluoride ions in the wastewater in the defluorination complexing agent reaction tank, and the addition period Tt is in hours.

[0123] Specifically, this invention accurately calculates the addition cycle of the defluorination complexing agent based on the concentration of tert-fluoride ions in the wastewater in the defluorination complexing agent reaction tank, precisely controls the conditional rate of the defluorination complexing agent, ensures the full occurrence of the defluorination reaction, and avoids waste caused by excessive addition of the agent.

[0124] Specifically, under the condition of defluorination in the defluorination complexing agent reaction tank, the second analysis unit determines whether to discharge the wastewater in the defluorination complexing agent reaction tank into the defluorination complexing agent sedimentation tank based on the comparison result of the third fluoride ion concentration C and the fourth preset fluoride ion concentration C0 in the wastewater in the defluorination complexing agent reaction tank.

[0125] If C≤C0, then the second analysis unit determines that the wastewater in the defluorination complexing agent reaction tank should be discharged into the defluorination complexing agent sedimentation tank;

[0126] If C > C0, then the second analysis unit determines that the wastewater in the defluorination complexing agent reaction tank should not be discharged into the defluorination complexing agent sedimentation tank.

[0127] In this embodiment of the invention, the fourth preset fluoride ion concentration C0 is 1 ppm. Those skilled in the art can adjust the fourth preset fluoride ion concentration C0 according to specific circumstances.

[0128] Specifically, this invention determines whether to discharge the wastewater in the defluorination complexing agent reaction tank into the defluorination complexing agent sedimentation tank based on the comparison between the third fluoride ion concentration and the fourth preset fluoride ion concentration in the wastewater in the defluorination complexing agent reaction tank, thus accurately determining whether the defluorination by the defluorination complexing agent is complete and proceeding to the next step of sedimentation.

[0129] Specifically, the second analysis unit determines whether to discharge the wastewater in the effluent storage tank into the collection tank based on the comparison result between the fourth fluoride ion concentration D and the fifth preset fluoride ion concentration D0 in the wastewater in the effluent storage tank.

[0130] If D≤D0, then it is determined that the wastewater in the effluent storage tank will not be discharged into the collection tank;

[0131] If D > D0, then the wastewater in the temporary storage tank will be discharged into the collection tank.

[0132] In this embodiment of the invention, the fifth preset fluoride ion concentration D0 is 2 ppm. Those skilled in the art can adjust the fifth preset fluoride ion concentration D0 according to specific circumstances.

[0133] Specifically, the present invention determines whether to discharge the wastewater in the effluent storage tank into the collection tank based on the comparison between the fourth fluoride ion concentration and the fifth preset fluoride ion concentration of the wastewater in the effluent storage tank. Since the precipitate may undergo secondary dissolution during the sedimentation process, resulting in an increase in the fluoride ion concentration, the fluoride ion concentration is detected again so that if the fluoride ion concentration does not meet the standard, the wastewater is returned to the collection tank for treatment.

[0134] The technical solution of the present invention has been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the scope of protection of the present invention.

[0135] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A defluoridation unit, characterized in that, The device comprises a dosing unit, a stirring unit, a detection unit, a data acquisition unit, a first analysis unit and a second analysis unit. The dosing unit comprises a PH adjusting dosing device connected with the water collecting pool, a calcium chloride dosing device connected with the calcium chloride reaction pool and a fluoride removing complexing agent dosing device connected with the fluoride removing complexing agent reaction pool. The stirring unit comprises a first stirrer arranged above the calcium chloride reaction pool and a second stirrer arranged above the fluoride removing complexing agent reaction pool. The detection unit comprises a PH detection device and a first fluoride ion detection device arranged in the water collecting pool, a second fluoride ion detection device arranged in the calcium chloride reaction pool, a third fluoride ion detection device arranged in the fluoride removing complexing agent reaction pool and a fourth fluoride ion detection device arranged in the water storage pool. The data acquisition unit is connected with the PH detection device, the first fluoride ion detection device, the second fluoride ion detection device, the third fluoride ion detection device and the fourth fluoride ion detection device respectively, and is used to acquire the first fluoride ion concentration of the wastewater in the water collecting pool, the second fluoride ion concentration of the wastewater in the calcium chloride reaction pool, the third fluoride ion concentration of the wastewater in the fluoride removing complexing agent reaction pool and the fourth fluoride ion concentration of the wastewater in the water storage pool. The first analysis unit is connected with the data acquisition unit, and is used to determine the treatment mode of the wastewater in the water collecting pool according to the first fluoride ion concentration of the wastewater in the water collecting pool. The first analysis unit determines the first treatment mode of the wastewater in the water collecting pool based on the comparison result that the first fluoride ion concentration of the wastewater in the water collecting pool is less than the first preset fluoride ion concentration, the second treatment mode of the wastewater in the water collecting pool based on the comparison result that the first fluoride ion concentration of the wastewater in the water collecting pool is greater than the second preset fluoride ion concentration, or the preliminary determination of the wastewater in the water collecting pool based on the comparison result that the first fluoride ion concentration of the wastewater in the water collecting pool is greater than or equal to the first preset fluoride ion concentration and less than or equal to the second preset fluoride ion concentration. The first analysis unit determines the second treatment mode of the wastewater in the water collecting pool based on the comparison result that the wastewater state evaluation value of the wastewater in the water collecting pool is greater than the second preset wastewater state evaluation value, and determines the first treatment mode of the wastewater in the water collecting pool based on the comparison result that the wastewater state evaluation value of the wastewater in the water collecting pool is greater than or equal to the first preset wastewater state evaluation value and less than or equal to the second preset wastewater state evaluation value. Or, the treatment mode of the wastewater in the water collecting pool is determined according to the wastewater state evaluation value of the wastewater in the water collecting pool. Or, the treatment mode of the wastewater in the water collecting pool is determined according to the relative difference between the PH of the wastewater in the water collecting pool and the first preset PH. The second analysis unit is connected with the data acquisition unit, and is used to determine the adding mode of the calcium chloride added into the calcium chloride reaction pool according to the second fluoride ion concentration of the wastewater in the calcium chloride reaction pool, to determine whether the wastewater in the calcium chloride reaction pool is discharged into the calcium chloride precipitation pool according to the second fluoride ion concentration of the wastewater in the calcium chloride reaction pool, to determine the adding period of the fluoride removing complexing agent, and to determine whether the wastewater in the fluoride removing complexing agent reaction pool is discharged into the fluoride removing complexing agent precipitation pool according to the third fluoride ion concentration of the wastewater in the fluoride removing complexing agent reaction pool. determining whether to discharge the wastewater in the temporary effluent storage tank into the collecting tank according to the fourth fluoride ion concentration of the wastewater in the temporary effluent storage tank; a control unit connected with the first analysis unit and the second analysis unit respectively, for controlling the equipment to remove fluoride according to the analysis results of the first analysis unit and the second analysis unit.

2. The fluoride-removal apparatus of claim 1, wherein The first analysis unit determines to make secondary determination on the wastewater based on the comparison result that the wastewater state evaluation value is less than the first preset wastewater state evaluation value, determines to treat the wastewater in the first treatment mode based on the comparison result that the relative difference is less than or equal to the first preset relative difference, and determines to treat the wastewater in the second treatment mode based on the comparison result that the relative difference is greater than the first preset relative difference.

3. The device for defluoridation, as claimed in claim 2, wherein, The first analysis unit calculates the wastewater state evaluation value according to the following formula, wherein: wherein, P represents the wastewater state evaluation value, S represents the pH value of the wastewater in the collecting tank, and A represents the first fluoride ion concentration.

4. The device for defluoridation, as claimed in claim 3, wherein, The second analysis unit determines to add calcium chloride to the calcium chloride reaction tank in the first adding mode based on the comparison result that the second fluoride ion concentration of the wastewater in the calcium chloride reaction tank is less than or equal to the third preset fluoride ion concentration, wherein the first adding mode is to add calcium chloride intermittently with the first preset time length as a period; determines to add calcium chloride to the calcium chloride reaction tank in the second adding mode based on the comparison result that the second fluoride ion concentration is greater than the third preset fluoride ion concentration, wherein the second adding mode is to add calcium chloride intermittently with the second preset time length as a period.

5. The device for defluoridation, as claimed in claim 4, wherein, The second analysis unit calculates the adding period of the fluoride removal complexing agent according to the following formula, wherein: wherein, Tt represents the adding period, and C represents the third fluoride ion concentration of the wastewater in the fluoride removal complexing agent reaction tank.

6. The device for defluoridation, as claimed in claim 5, wherein, The second analysis unit determines to discharge the wastewater in the calcium chloride reaction tank into the calcium chloride precipitation tank based on the comparison result that the second fluoride ion concentration of the wastewater in the calcium chloride reaction tank is less than or equal to the first preset fluoride ion concentration. determines to discharge the wastewater in the fluoride removal complexing agent reaction tank into the fluoride removal complexing agent precipitation tank based on the comparison result that the third fluoride ion concentration of the wastewater in the fluoride removal complexing agent reaction tank is less than or equal to the fourth preset fluoride ion concentration.

7. The device for defluoridation, according to claim 6, wherein, The second analysis unit determines to discharge the wastewater in the temporary effluent storage tank into the collecting tank based on the comparison result that the fourth fluoride ion concentration of the wastewater in the temporary effluent storage tank is greater than the fifth preset fluoride ion concentration.

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