Advanced treatment system for high-phosphorus fluorine-containing wastewater

Abstract

The utility model discloses an advanced treatment system for high-phosphorus fluorine-containing wastewater, which comprises a high-phosphorus fluorine-containing wastewater homogenizing tank, the high-phosphorus fluorine-containing wastewater homogenizing tank is sequentially connected with a reaction system, a first sedimentation tank, a pretreatment tank, a second sedimentation tank and a clarification tank, and the bottom of each of the first sedimentation tank and the second sedimentation tank is provided with a sludge discharge port. An unqualified water production port of the clarification tank is connected with a high-phosphorus fluorine-containing wastewater homogenizing tank, and a qualified water production port of the clarification tank is sequentially connected with an advanced treatment pretreatment filtering device, a filtering water tank, a high-phosphorus high-fluorine advanced treatment resin exchange tower and a water production tank; a water outlet of the high-fluorine advanced treatment resin exchange tower is connected with the washing and regeneration water inlet main pipeline, and the high-fluorine advanced treatment resin exchange tower is connected with the regeneration dosing device through the washing and regeneration water inlet main pipeline. When the device is used for treating phosphorus-containing and fluorine-containing wastewater generated by manufacturing electronic chips, the phosphorus and fluorine removal rate reaches 99% or above.

Description

Technical Field

[0001] This utility model relates to the field of wastewater treatment technology, and in particular to a deep treatment system for high-phosphorus and fluoride-containing wastewater. Background Technology

[0002] In the chip wastewater industry, due to the complexity of the production process, the fluoride-containing wastewater discharged during manufacturing contains a large amount of phosphoric acid pollutants. Since the wastewater treatment system only targets fluoride ions, it cannot completely degrade phosphorus, resulting in phosphorus exceeding the standard at the total discharge outlet.

[0003] Common fluoride-containing wastewater treatment processes generally include homogenization tanks, pH adjustment tanks, reaction tanks, coagulation tanks and flocculation tanks, sedimentation tanks and clarification tanks. Because these processes target only fluorides, they are difficult to remove from fluoride- and phosphorus-containing wastewater. Utility Model Content

[0004] The purpose of this invention is to provide a deep treatment system for high-phosphorus and fluoride-containing wastewater. This system is designed for the deep treatment of high-phosphorus and fluoride-containing wastewater generated during the electronic chip manufacturing process.

[0005] To address the problems existing in the prior art, the technical solution adopted by this utility model is as follows:

[0006] Firstly, this utility model provides a high-phosphorus and high-fluoride wastewater deep treatment system, comprising a high-phosphorus and high-fluoride wastewater homogenization tank, a reaction system, a first sedimentation tank, a pretreatment tank, a second sedimentation tank, a clarification tank, a deep treatment pretreatment filtration device, a filter water tank, a high-phosphorus and high-fluoride deep treatment resin exchange tower, a product water tank, and a regeneration dosing device. The high-phosphorus and high-fluoride wastewater homogenization tank is connected to the inlet of the reaction system, the outlet of the reaction system is connected to the first sedimentation tank, the supernatant outlet of the first sedimentation tank is connected to the pretreatment tank, and the outlet of the pretreatment tank is connected to the second sedimentation tank. The upper effluent weir of the second sedimentation tank is connected to the clarification tank. Both the first and second sedimentation tanks are equipped with sludge discharge outlets at their bottoms. The unqualified product water outlet of the clarification tank is connected to the high-phosphorus and high-fluoride wastewater. The qualified product water outlet of the clarification tank is sequentially connected to the advanced treatment pretreatment filtration device, the filtration water tank, the high-phosphorus and high-fluoride advanced treatment resin exchange tower, and the product water tank. The effluent outlet of the high-fluoride advanced treatment resin exchange tower is connected to the flushing and regeneration inlet main pipeline. The high-fluoride advanced treatment resin exchange tower and the regeneration dosing device are connected through the flushing and regeneration inlet main pipeline.

[0007] Furthermore, the reaction system comprises five sequentially connected reaction tanks: a pH adjustment tank, a first reaction tank, a second reaction tank, a coagulation tank, and a flocculation tank. The pH adjustment tank is used to adjust the pH value of the high-phosphorus and fluoride-containing wastewater and to add a phosphorus removal agent. The first and second reaction tanks are used to adjust the pH value of the high-phosphorus and fluoride-containing wastewater and to add CaCl2. The coagulation tank is used to adjust the pH value of the high-phosphorus and fluoride-containing wastewater and to add polyaluminum chloride (PAC) and CaCl2. The flocculation tank is used to add polyacrylamide (PAM). By adjusting the pH range required for the reaction and adding a phosphorus removal agent, CaCl2, PAC, and PAM to the wastewater, the reaction system removes large amounts of phosphate, fluoride, and suspended solids from the water.

[0008] This invention adjusts the pH of the pH adjustment tank, the first reaction tank, the second reaction tank, and the coagulation tank. Even with large water volume and large fluctuations in water quality, the water quality can be adjusted to a suitable pH value, thereby ensuring the subsequent processes.

[0009] Furthermore, the pH adjustment tank is equipped with a pH meter and a stirrer; the first reaction tank, the second reaction tank, and the coagulation tank are all equipped with pH meters, fluoride ion meters, and stirrers; the flocculation tank is equipped with a stirrer.

[0010] Furthermore, the regeneration dosing device includes a NaOH extractor, a NaOH metering tank, a NaOH replenishment pipe, and a NaOH storage tank. The NaOH storage tank and the NaOH metering tank are connected by the NaOH replenishment pipe. One end of the NaOH extractor is connected to the bottom outlet pipe of the NaOH metering tank through a regeneration alkali injection valve, and the other end is connected to the main flushing and regeneration inlet pipeline.

[0011] Furthermore, the deep processing pretreatment filtration device includes a multi-media filter and an activated carbon filter.

[0012] Furthermore, the high-phosphorus and high-fluoride deep treatment resin exchange tower includes an anion bed (phosphate removal tower) and an anion bed (fluoride removal resin tower), and the high-fluoride deep treatment resin exchange tower is filled with an ion exchange resin with regeneration capability. Preferably, the ion exchange resin is a phosphorus removal ion exchange resin and a fluoride removal ion exchange resin.

[0013] Furthermore, the high-phosphorus and fluoride wastewater homogenization tank is connected to the reaction system via a booster pump, and an aeration device is installed in the high-phosphorus and fluoride wastewater homogenization tank; a flow meter is installed at the outlet of the booster pump.

[0014] Furthermore, the clarification tank is equipped with a fluoride ion meter and an online total phosphorus detector, and the clarification tank is connected to a high-phosphorus and fluoride-containing wastewater equalization tank and a deep treatment pretreatment filtration device via a transfer pump.

[0015] Furthermore, the sludge discharge ports at the bottom of the first sedimentation tank and the second sedimentation tank are both connected to the sludge thickening tank via sludge discharge pumps, and the sludge thickening tank is connected to the sludge treatment system.

[0016] Furthermore, the filtration pool is connected to a high-phosphorus, high-fluorine deep treatment resin exchange tower via a transfer pump.

[0017] The reaction system is used to adjust the pH value of high-phosphorus and fluoride wastewater and to add phosphorus removal agents, CaCl2, polyaluminum chloride, and polyacrylamide. The reaction system and the first sedimentation tank constitute the primary phosphorus and fluoride removal system. The pretreatment tank, second sedimentation tank, clarification tank, advanced treatment pretreatment filtration device, filtration tank, and high-fluoride advanced treatment resin exchange tower constitute the secondary advanced treatment system. The secondary advanced treatment system is used to add CaCO3, NaHSO3, and defluorinating agents to further reduce the fluoride content in the wastewater, while also reducing the residual Ca in the reaction system. 2+ This process protects SA-1 and SA-2 resins and extends their service life. SA-1 and SA-2 reduce the content of phosphate and fluoride ions in wastewater through ion exchange, ensuring that it meets discharge requirements.

[0018] Secondly, this utility model provides a method for treating high-phosphorus and fluoride wastewater using the high-phosphorus and fluoride wastewater deep treatment system described in the first aspect above, comprising the following steps:

[0019] (1) After the high phosphorus and fluoride wastewater is uniformly mixed in the high phosphorus and fluoride wastewater homogenization tank, it is sent to the pH adjustment tank to adjust the pH value. At the same time, phosphorus removal agent is added and stirred to remove most of the phosphate in the wastewater. Then the water is discharged into the first reaction tank.

[0020] (2) Adjust the pH values ​​of the first reaction tank and the second reaction tank in sequence. Add CaCl2 to the first reaction tank and the second reaction tank in sequence according to the fluoride ion content and stir the reaction. Then, drain the water into the coagulation tank.

[0021] (3) Adjust the pH value of the coagulation tank, add CaCl2 and polyaluminum chloride to the coagulation tank, stir and react, and then discharge the water into the flocculation tank;

[0022] (4) Adjust the pH value of the flocculation tank, add polyacrylamide to the flocculation tank and stir to react. The effluent from the flocculation tank flows into the first sedimentation tank, the sludge in the first sedimentation tank is discharged into the sludge thickening tank, and the supernatant in the first sedimentation tank flows into the pretreatment water tank.

[0023] (5) Add NaHSO3, Na2CO3 and defluorinating agent to the pretreatment tank, mix and stir evenly to remove oxides in the water and further remove fluorides in the water;

[0024] (6) After the effluent from the pretreatment tank passes through the second sedimentation tank and the clarification tank in sequence, the unqualified product water flows into the high phosphorus and fluoride wastewater equalization tank; the qualified product water enters the filter water tank after being filtered by the deep treatment pretreatment filtration device. The effluent from the filter water tank passes through the high fluoride deep treatment resin exchange tower to remove phosphorus and fluoride pollutants in the wastewater, and finally flows into the product water tank.

[0025] This invention improves the defluorination effect by first adding a dephosphorizing agent to the primary dephosphorization and defluorination system and then adding a defluorinating agent through the secondary deep treatment system.

[0026] Furthermore, the reaction time of the pH adjustment tank, the first reaction tank, the second reaction tank, the coagulation tank, and the flocculation tank is ≥25 minutes, preferably 30 minutes.

[0027] Furthermore, the pH value of the wastewater in the pH adjustment tank, the first reaction tank, the second reaction tank, and the coagulation tank is adjusted to 7.0-7.8, preferably 7.5, by adding NaOH or H2SO4.

[0028] Furthermore, the amount of PAC added in the coagulation tank is 150-200 mg / L, preferably 150 mg / L; the amount of PAM added in the flocculation tank is 6-10 mg / L, preferably 8 mg / L. Adding PAC and PAM according to the amounts described in this application can remove pollutants with maximum efficiency and save costs.

[0029] Furthermore, the mass ratio of Ca ions to fluoride ions (kg / h) in the first reaction tank, the second reaction tank, and the coagulation tank is 19:10-13, preferably 19:12. This ratio can remove pollutants with maximum efficiency and save costs.

[0030] Furthermore, the ion exchange resin in the high-fluorine deep treatment resin exchange tower is regenerated using NaOH solution.

[0031] Furthermore, the ion exchange resin in the anion bed (excluding the phosphate ester tower) is regenerated using a 2-3 BV NaOH solution with a mass fraction of 4-6%, preferably a 2.5 BV NaOH solution with a mass fraction of 5%.

[0032] The ion exchange resin in the anion exchange bed (fluoride removal resin tower) is regenerated using a 2-3 BV, 0.04-0.4% NaOH solution (pH 12-13). Preferably, a 2.5 BV, 0.4% NaOH solution is used.

[0033] The advantages and beneficial effects of this utility model are:

[0034] This invention relates to an advanced treatment system for high-phosphorus and fluoride-containing wastewater. By incorporating a primary phosphorus and fluoride removal system and a secondary advanced treatment system, it can remove both fluoride and phosphorus simultaneously, avoiding the harmful effects of excessive phosphorus levels. Compared to traditional chemical precipitation methods, this system utilizes ion exchange, producing less sludge and reducing subsequent sludge treatment costs and environmental impact. Furthermore, this method is recyclable and reusable, with low long-term operating costs, making it suitable for various scenarios, including industrial wastewater treatment.

[0035] This invention discloses a method for the advanced treatment of high-phosphorus and fluoride wastewater generated from electronic chip manufacturing. The method involves the addition of a phosphorus removal agent, CaCl2, PAC, and PAM for flocculation and sedimentation to remove phosphate and fluoride from the water. Specifically, calcium chloride is added to the wastewater. 2+ and F - The reaction produces a sparingly soluble CaF2 precipitate; calcium hydroxide, a phosphorus removal agent, is added to the wastewater, Ca... 2+ Ions and PO4 3- Ion reactions produce Ca3(PO4)2 precipitate; the addition of PAC and PAM to wastewater causes coagulation and flocculation reactions, resulting in precipitation. A defluoridating agent is added to the effluent from the primary sedimentation tank, Fe... 2+ Ions and F - The ions undergo a complexation reaction, further reducing the fluoride content in the wastewater. The reaction formula is as follows:

[0036] (1)

[0037] (2)

[0038] (3)

[0039] (4).

[0040] This invention employs an ion exchange deep treatment process to remove phosphorus and fluoride pollutants from water, providing deep treatment for high-phosphorus and fluoride-containing wastewater generated during electronic chip manufacturing, achieving a phosphorus and fluoride removal efficiency of over 99%. Attached Figure Description

[0041] Figure 1 This is a schematic diagram of the structure of a high-phosphorus and fluoride-containing wastewater deep treatment system according to the present invention;

[0042] In the diagram: pH adjustment tank 1, first reaction tank 2, second reaction tank 3, coagulation tank 4, flocculation tank 5, first sedimentation tank 6, pretreatment tank 7, second sedimentation tank 8, clarification tank 9, multi-media filter 10, activated carbon filter 11, filtered water tank 12, anion bed (phosphate removal tower) 13, anion bed (fluoride removal resin tower) 14, product water tank 15, booster pump 16, high-phosphorus and fluoride wastewater equalization tank 17, sludge thickening tank 18, sludge treatment system 19, SA-2 regeneration pump 20, SA-1 regeneration pump 21, regeneration dosing device 22, regeneration dosing device 23, unqualified return pump 24;

[0043] Figure 2 This diagram shows the pipeline layout for the SA-1 regeneration pump system, including the production water, regeneration drainage, and flushing drainage. In the diagram, the main flushing and regeneration inlet pipeline is 25.

[0044] Figure 3 This is a schematic diagram of the regenerative dosing device.

[0045] In the diagram: NaOH extractor 221, NaOH metering tank 222, NaOH replenishment pipe 223, NaOH storage tank 224. Detailed Implementation

[0046] The technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application are within the scope of protection of this application.

[0047] Unless otherwise specified, the experimental methods used in the following examples are conventional methods, performed according to the techniques or conditions described in the literature in this field or according to the product instructions. Unless otherwise specified, the materials and reagents used in the following examples are commercially available.

[0048] Example 1

[0049] like Figure 1 As shown, this embodiment provides a high-phosphorus and fluoride-containing wastewater deep treatment system, including a high-phosphorus and fluoride-containing wastewater equalization tank 17, a primary phosphorus and fluoride removal system, a secondary deep treatment system, a product water tank 15, and a regeneration dosing device.

[0050] The primary phosphorus and fluoride removal system comprises a reaction system and a first sedimentation tank 6. The reaction system is used to adjust the pH value of high-phosphorus and fluoride-containing wastewater and to add phosphorus removal agents, CaCl2, PAC, and PAM. It includes a pH adjustment tank 1, a first reaction tank 2, a second reaction tank 3, a coagulation tank 4, and a flocculation tank 5. The pH adjustment tank 1 is equipped with a pH meter and a stirrer, used to adjust the pH value of the high-phosphorus and fluoride-containing wastewater while simultaneously adding phosphorus removal agents. The first reaction tank 2, the second reaction tank 3, and the coagulation tank 4 are all equipped with pH meters, fluoride ion meters (F), and stirrers. All three tanks are used to adjust the pH value of the high-phosphorus and fluoride-containing wastewater while simultaneously adding CaCl2. The coagulation tank 4 is also used to add PAC. The flocculation tank 5 is used to add PAM and is equipped with a stirrer. Acid and alkali addition valves are installed at the inlets of the pH adjustment tank 1, the first reaction tank 2, the second reaction tank 3, and the coagulation tank 4.

[0051] This invention allows for the manual addition of NaOH or H2SO4, or the addition of NaOH or H2SO4 using the multi-stage automatic dosing control device disclosed in Chinese Utility Model Patent Publication No. CN208327501U. Both the acid and alkali valves used in this invention are intelligent control valves and are commercially available products. The multi-stage automatic dosing control device automatically controls the acid and alkali addition process by controlling the intelligent control valves based on the pH meter readings.

[0052] The control program for the dosing system is generated using the industrial configuration software INTOUCH. Alternatively, other commercially available software can be used to implement the dosing control process of this invention, or a manual dosing control process can be employed.

[0053] The high-phosphorus and fluoride wastewater equalization tank 17 is equipped with an aeration device. The high-phosphorus and fluoride wastewater equalization tank 17 is connected to the pH adjustment tank 1 via a lift pump 16, and the outlet of the lift pump 16 is equipped with a flow meter. The pH adjustment tank 1 is connected in sequence to the first reaction tank 2, the second reaction tank 3, the coagulation tank 4, and the flocculation tank 5. The outlet of the flocculation tank 5 is connected to the first sedimentation tank 6, and the sludge discharge outlet of the first sedimentation tank 6 is connected to the sludge thickening tank 18. The sludge from the sludge thickening tank 18 enters the sludge treatment system 19, and is transported off-site for treatment after dewatering.

[0054] The secondary advanced treatment system includes a pretreatment tank 7, a second sedimentation tank 8, a clarification tank 9, an advanced treatment pretreatment filtration device, a filtered water tank 12, and a high-phosphorus, high-fluoride advanced treatment resin exchange tower connected in sequence. The pretreatment tank 7 is used to add NaHSO3, Na2CO3, and a defluorinating agent, and is equipped with an ORP meter. The advanced treatment pretreatment filtration device includes a multi-media filter (MMF) 10 and an activated carbon filter (ACF) 11. The high-phosphorus, high-fluoride advanced treatment resin exchange tower includes an anion bed (phosphate removal tower) 13 (SA-1) and an anion bed (fluoride removal resin tower) 14 (SA-2). SA-1 is filled with a phosphorus removal ion exchange resin with regeneration capabilities; in this embodiment, Dusheng ion exchange resin A-107 is used. SA-2 is filled with a fluoride removal ion exchange resin with regeneration capabilities; in this embodiment, Tulsion CH-35 ion exchange resin is used.

[0055] The supernatant outlet of the first sedimentation tank 6 is connected to the pretreatment tank 7. The outlet of the pretreatment tank 7 is connected to the second sedimentation tank 8. The upper effluent weir of the second sedimentation tank 8 is connected to the clarifier 9. The sludge discharge outlet at the bottom of the second sedimentation tank 8 is connected to the sludge thickening tank 18. The sludge from the sludge thickening tank enters the sludge treatment system, is dewatered, and then transported off-site for treatment. The clarifier 9 is equipped with a fluoride ion meter (F) and an online total phosphorus analyzer (TP). The non-compliant product outlet of the clarifier 9 is connected to the high-phosphorus and fluoride-containing wastewater tank 17 via a transfer pump. The compliant product outlet of the clarifier 9 is connected to MMF10 and ACF11 sequentially via a transfer pump. The outlet of ACF11 is connected to the filter tank 12.

[0056] like Figure 2 As shown, the outlet of the filtration tank 12 is connected to the inlet manifold at the top of SA-1 via a transfer pump, inlet valve AV-SA1-01, and inlet pipe. The product water manifold at the bottom of SA-1 is connected to the inlet manifold at the top of SA-2 via product water valve AV-SA1-02. The product water manifold at the bottom of SA-2 is connected to the product water tank 15. The product water tank 15 is equipped with a pH meter, a fluoride ion meter (F), and an online total phosphorus analyzer (TP). The product water outlet of the product water tank 15 is connected to the SA-2 regeneration pump 20, the SA-1 regeneration pump 21, the unqualified return pipeline, the greywater reuse pipeline, and the qualified discharge pipeline, respectively. The unqualified return pipeline is connected to the inlet of the filtration tank, and an unqualified return pump 24 is installed on the unqualified return pipeline. The greywater reuse pipeline is connected to the pure water system's filter tank. The filter tank is part of the pure water pretreatment system. It is the product water tank after the raw water has passed through the MMF filter to remove insoluble substances and colloids. It is used together with the filtered raw water.

[0057] The outlet of SA-1 regeneration pump 21 is connected to the flushing and regeneration inlet water main pipeline 25. A regeneration dosing device 23 is installed on the flushing and regeneration inlet water main pipeline 25. The outlet of the flushing and regeneration inlet water main pipeline 25 is connected to the forward wash inlet water pipeline and the backwash, flushing and regeneration inlet water pipeline respectively. The forward wash inlet water pipeline is connected to the top inlet water manifold of SA-1 regeneration pump through the forward wash inlet water valve AV-SA1-03. The bottom product water manifold of SA-1 regeneration pump is connected to the forward wash drain water pipeline through the forward wash drain water valve AV-SA1-04. The forward wash drain water pipeline is connected to the high phosphorus and fluoride homogenization tank.

[0058] The backwash, flushing, and regeneration inlet pipelines are connected to the regeneration pipeline and the backwash pipeline, respectively. The regeneration pipeline is connected to the bottom product water manifold of SA-1 via the regeneration inlet valve AV-SA1-05, and the backwash pipeline is connected to the bottom product water manifold of SA-1 via the regeneration backwash valve AV-SA1-07. The top inlet manifold of SA-1 is connected to the backwash, flushing, and regeneration drain pipeline via the regeneration and backwash drain valve AV-SA1-06. The backwash, flushing, and regeneration drain pipeline is connected to the high-phosphorus and fluoride homogenization tank.

[0059] The piping connection of SA-2 regeneration pump 20 is the same as that of SA-1 regeneration pump 21. The outlet of SA-2 regeneration pump 20 is connected to the main flushing and regeneration inlet pipe 25. A regeneration dosing device 22 is installed on the main flushing and regeneration inlet pipe 25. The outlet of the main flushing and regeneration inlet pipe 25 is connected to the forward wash inlet pipe and the backwash, flushing and regeneration inlet pipe respectively. The forward wash inlet pipe is connected to the top inlet manifold of SA-2 through the forward wash inlet valve. The bottom product water manifold of SA-2 regeneration pump is connected to the forward wash drain pipe through the forward wash drain valve. The forward wash drain pipe is connected to the high phosphorus and fluoride homogenization tank.

[0060] The backwash, flushing, and regeneration inlet pipelines are connected to the regeneration pipeline and backwash pipeline, respectively. The regeneration pipeline is connected to the bottom product water manifold of the SA-2 regeneration pump via a regeneration inlet valve, and the backwash pipeline is connected to the bottom product water manifold of the SA-2 regeneration pump via a regeneration backwash valve. The top inlet manifold of the SA-2 regeneration pump is connected to the backwash, flushing, and regeneration drain pipelines via regeneration and backwash drain valves. The backwash, flushing, and regeneration drain pipelines are connected to the high-phosphorus fluoride homogenization tank.

[0061] like Figure 3As shown, the regeneration dosing device 23 includes a NaOH extractor 221, a NaOH metering tank 222, a NaOH replenishment pipe 223, and a NaOH storage tank 224. The NaOH storage tank 224 is connected to the NaOH metering tank 222 via the NaOH replenishment pipe 223 and a transfer pump, which transports the NaOH solution from the NaOH storage tank to the NaOH metering tank. The NaOH extractor 221 is installed on one side of the NaOH metering tank 222. One end of the NaOH extractor 221 is connected to the bottom outlet pipe of the NaOH metering tank 222 via a regeneration alkali injection valve AV-SA1-08, and the other end is connected to the main flushing and regeneration inlet water pipeline 25. The NaOH storage tank 224 stores a 30% NaOH solution.

[0062] The regeneration dosing device 22 and the regeneration dosing device 23 have the same structure.

[0063] Taking SA-1 regeneration pump 21 as an example, the steps are as follows:

[0064] 1) Operation: Open the product water valve AV-SA1-02 and the inlet water valve AV-SA1-01, close other valves, and start the filter water tank transfer pump;

[0065] 2) Forward wash: Open the forward wash drain valve AV-SA1-04 and the forward wash inlet valve AV-SA1-03, close other valves, and start the SA-1 regeneration pump;

[0066] 3) Backwash: Open the backwash and regeneration drain valve AV-SA1-06 and the backwash inlet valve AV-SA1-07, close other valves, and start the SA-1 regeneration pump;

[0067] 4) Regeneration: Open the backwash, regeneration drain valve AV-SA1-06, regeneration inlet valve AV-SA1-05, and regeneration alkali injection valve AV-SA1-08, close other valves, and start the SA-1 regeneration pump.

[0068] Example 2

[0069] like Figure 1 As shown, the method for deep treatment of high-phosphorus and fluoride wastewater using the high-phosphorus and fluoride wastewater deep treatment system described in Example 1 includes the following steps:

[0070] This embodiment describes the advanced treatment of high-phosphorus and fluoride-containing wastewater generated from electronic chip manufacturing. The main pollutants in this wastewater are phosphate and fluoride.

[0071] (1) High-phosphorus and fluoride-containing wastewater was collected in the high-phosphorus and fluoride wastewater equalization tank 17. Testing showed that the phosphate concentration in the wastewater was 150 mg / L and the fluoride concentration was 600 mg / L. The wastewater in the equalization tank 17 was stirred and mixed evenly using an aeration device. It was then pumped into the pH adjustment tank 1 via a lift pump 16. In the pH adjustment tank 1, NaOH or H2SO4 was added to adjust the pH to 7.5. Simultaneously, a phosphorus removal agent was added and the mixture was stirred for 30 minutes to remove most of the phosphate in the wastewater before flowing into the first reaction tank 2. In this embodiment, the phosphorus removal agent selected was calcium salt Ca(OH)2. The dosage of the phosphorus removal agent was based on the average total phosphorus detection value after 15 days of continuous operation of the high-phosphorus and fluoride wastewater equalization tank, with a calcium ion dosage of 300 ppm.

[0072] (2) In the first reaction tank 2, add NaOH or H2SO4 to adjust the pH value to 7.5. Add CaCl2 to the first reaction tank 2 according to the fluoride ion content and stir the reaction for 30 min. The ratio of Ca ion mass to fluoride ion mass (kg / h) in the first reaction tank 2 is 19:12.

[0073] (3) The effluent from the first reaction tank 2 flows into the second reaction tank 3. In the second reaction tank 3, NaOH or H2SO4 is added to adjust the pH value to 7.5. At the same time, CaCl2 is added to the second reaction tank 3 according to the fluoride ion content, and the reaction is stirred for 30 minutes. The mass ratio of Ca ions to fluoride ions (kg / h) in the second reaction tank 3 is 19:12. After testing, the phosphorus in the effluent of the second reaction tank 3 is <5mg / L and the fluoride is <25mg / L. The effluent from the second reaction tank 3 flows into the coagulation tank 4.

[0074] (4) Add NaOH or H2SO4 to the coagulation tank 4 to adjust the pH value to 7.5. At the same time, add CaCl2 to the coagulation tank 4 according to the fluoride ion content and stir for 30 min. The ratio of Ca ion mass to fluoride ion mass (kg / h) in the coagulation tank 4 is 19:12.

[0075] (5) Add PAC to coagulation tank 4 at a rate of 150 mg / L. Stir well and react for 30 minutes. Then, the effluent from coagulation tank 4 flows into flocculation tank 5.

[0076] (6) Add PAM to flocculation tank 5 and stir evenly. React for 30 minutes. The amount of PAM added is 8 ppm.

[0077] (7) Then the effluent from the flocculation tank 5 flows into the first sedimentation tank 6. Under the action of gravity, the mud and water are separated. The sludge settles to the bottom and is discharged into the sludge thickening tank 18 by the sludge discharge pump. The sludge is dewatered by the sludge treatment system 19 and then transported for treatment. The supernatant overflows from the effluent weir of the first sedimentation tank 6 to the pretreatment tank 7. According to the test, the phosphorus in the effluent of the first sedimentation tank 6 is <3mg / L and the fluoride is <15mg / L.

[0078] (8) Add NaHSO3, Na2CO3 and defluorinating agent to pretreatment tank 7, mix and stir to remove oxides from the water and further remove fluorides from the water. The defluorinating agent is an iron salt defluorinating agent. In this embodiment, polyferric sulfate is specifically used, which has low cost, good treatment effect and wide range of applications. The addition of NaHSO3 is controlled according to the ORP instrument reading to ensure that the oxidation-reduction potential (ORP) is <150mV; the dosage of defluorinating agent is 100ppm; the dosage of Na2CO3 is 100ppm.

[0079] (9) The effluent from the pretreatment tank 7 flows into the second sedimentation tank 8. The clear water after sedimentation flows into the clarification tank 9 from the upper effluent weir. The sludge in the second sedimentation tank 8 settles to the bottom. The sludge deposited at the bottom is discharged into the sludge thickening tank 18 by the sludge discharge pump. The sludge is dewatered by the sludge treatment system 19 and then transported off-site for treatment. According to the test, the effluent from the second sedimentation tank 8 has phosphorus <3mg / L, fluoride <5mg / L, and ORP <150mv.

[0080] (10) Wastewater flowing into clarifier 9 is controlled by switching the outlet valve according to the detection value of the sedimentation tank instrument. Unqualified product water is returned to the high phosphorus and fluoride wastewater equalization tank 17 by the transfer pump. Qualified product water is filtered through multi-media filter (MMF) 10 and activated carbon filter (ACF) 11 in sequence and then enters the filter water tank 12. After testing, the SDI of the effluent from the deep treatment pretreatment filter device is <3.5. The effluent from the filter water tank flows into the anion bed (phosphate removal tower) (SA-1) 13 and the anion bed (fluoride removal resin tower) (SA-2) 14 in sequence. The resin tower is filled with ion exchange resin, which can effectively remove phosphorus and fluoride pollutants in the wastewater. Finally, it flows into the product water tank 15.

[0081] According to the data from the online monitoring instruments F and TP, when the total phosphorus > 0.5 mg / L and fluoride > 1 mg / L, the unqualified return pump 24 is activated to pump the unqualified water from the product water tank into the filtration tank 12 for further treatment. Testing shows that the product water quality obtained using the equipment and method of this invention can achieve total phosphorus < 0.5 mg / L and fluoride < 1 mg / L. When the total phosphorus < 0.5 mg / L and fluoride < 1 mg / L, based on the reclaimed water reuse requirements, if the product water volume is less than the reuse requirement, all product water is reused; if the product water volume is greater than the reuse requirement, the excess product water is discharged through a qualified discharge pipeline.

[0082] The wastewater treated by this utility model meets the discharge standard of Class III surface water quality in the "Surface Water Environmental Quality Standard" (GB 3838-2002), thus achieving environmentally friendly emissions from the electronic chip industry.

[0083] The removal rates of phosphate and fluoride are calculated using the following formulas:

[0084] The phosphate removal rate is: (1-0.5 / 150)*100%>99%;

[0085] The fluoride removal rate is: (1-1 / 600)*100%>99%.

[0086] Calculations show that the phosphorus and fluoride removal rates using the present invention's treatment system and method both reach over 99%.

[0087] Furthermore, the ion exchange resin has a regeneration function. The ion exchange resin in the SA-1 regeneration pump 21 is regenerated using a 5% NaOH solution, and the ion exchange resin in the SA-2 regeneration pump 20 is regenerated using a 0.4% NaOH solution. The amount of both the 5% and 0.4% NaOH solutions used is 2.5 BV (BV is the resin volume). The NaOH storage tank 224 stores a 30% NaOH solution. The NaOH metering tank is used to measure the amount of NaOH required for regeneration, and the amount used is based on the amount of NaOH solution required for a single regeneration. The amount of NaOH solution required for a single regeneration using the 30% NaOH solution is 0.417 BV (BV is the resin solvent), and the ratio of the amount of 5% NaOH solution to the amount of 30% NaOH solution required for a single regeneration is 6:1.

[0088] 1) SA-1 regeneration pump regeneration method: Use a 5% NaOH solution at a flow rate of 4 BV / H for 30-60 min; backwash water: pure water / soft water / tap water, backwash flow rate: 5-10 BV / H, backwash time: 30 min.

[0089] 2) SA-2 regeneration pump regeneration method: Use 0.4% NaOH solution (pH 12-13) at a flow rate of 2-4 BV / H and a regeneration time of 30-60 min; backwash water: pure water / soft water / tap water, backwash flow rate: 4-6 BV / H, backwash time: 30 min.

[0090] The embodiments of this application have been described above with reference to the accompanying drawings. However, this application is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of this application without departing from the spirit and scope of the claims, and all of these forms are within the protection scope of this application.

Claims

1. A high phosphorus fluorine-containing wastewater advanced treatment system, characterized in that: The system includes a high-phosphorus and high-fluoride wastewater equalization tank (17), a reaction system, a first sedimentation tank (6), a pretreatment tank (7), a second sedimentation tank (8), a clarification tank (9), a deep treatment pretreatment filtration device, a filter water tank (12), a high-phosphorus and high-fluoride deep treatment resin exchange tower, a product water tank (15), and a regeneration dosing device. The high-phosphorus and high-fluoride wastewater equalization tank (17) is connected to the inlet of the reaction system, the outlet of the reaction system is connected to the first sedimentation tank (6), the supernatant outlet of the first sedimentation tank (6) is connected to the pretreatment tank (7), the outlet of the pretreatment tank (7) is connected to the second sedimentation tank (8), and the upper end of the second sedimentation tank (8) is connected to the pretreatment tank (7). The effluent weir is connected to the clarifier (9). The bottom of the first sedimentation tank (6) and the second sedimentation tank (8) are both equipped with sludge discharge outlets. The unqualified product water outlet of the clarifier (9) and the high phosphorus and fluoride wastewater are both connected to the pool (17). The qualified product water outlet of the clarifier (9) is connected in sequence to the deep treatment pretreatment filter device, the filter water pool (12), the high phosphorus and high fluoride deep treatment resin exchange tower and the product water pool (15). The outlet of the high fluoride deep treatment resin exchange tower is connected to the flushing and regeneration inlet water main pipeline (25). The high fluoride deep treatment resin exchange tower and the regeneration dosing device are connected through the flushing and regeneration inlet water main pipeline (25).

2. The high phosphorus fluorine-containing wastewater advanced treatment system according to claim 1, characterized in that: The reaction system includes five reaction tanks connected in sequence: pH adjustment tank (1), first reaction tank (2), second reaction tank (3), coagulation tank (4), and flocculation tank (5).

3. The high phosphorus fluorine-containing wastewater advanced treatment system according to claim 2, characterized in that: The pH adjustment tank (1) is equipped with a pH meter and a stirrer; the first reaction tank (2), the second reaction tank (3), and the coagulation tank (4) are all equipped with pH meters, fluoride ion meters, and stirrers, and the flocculation tank (5) is equipped with a stirrer.

4. The high phosphorus containing fluorine wastewater advanced treatment system according to claim 1, characterized in that: The regeneration dosing device includes a NaOH extractor (221), a NaOH metering tank (222), a NaOH replenishment pipe (223), and a NaOH storage tank (224). The NaOH storage tank (224) is connected to the NaOH metering tank (222) through the NaOH replenishment pipe (223). One end of the NaOH extractor (221) is connected to the bottom outlet pipe of the NaOH metering tank (222) through a regeneration alkali injection valve, and the other end is connected to the main flushing and regeneration inlet water pipeline (25).

5. The high phosphorus containing fluorine wastewater advanced treatment system according to claim 1, characterized in that: The deep processing pretreatment filtration device includes a multi-media filter (10) and an activated carbon filter (11).

6. The high phosphorus containing fluorine wastewater advanced treatment system according to claim 1, characterized in that: The high-phosphorus and high-fluorine deep treatment resin exchange tower includes an anion bed phosphate removal tower (13) and an anion bed fluoride removal resin tower (14), and the high-fluorine deep treatment resin exchange tower is filled with ion exchange resin with regeneration capability.

7. The high phosphorus containing fluorine wastewater advanced treatment system according to claim 1, characterized in that: The high-phosphorus and fluoride-containing wastewater homogenization tank (17) is connected to the reaction system via a booster pump (16). An aeration device is installed in the high-phosphorus and fluoride-containing wastewater homogenization tank (17). A flow meter is installed at the outlet of the booster pump (16).

8. The high phosphorus containing fluorine wastewater advanced treatment system according to claim 1, characterized in that: The clarification tank (9) is equipped with a fluoride ion meter and a total phosphorus online detector. The clarification tank (9) is connected to the high-phosphorus fluoride wastewater equalization tank (17) and the deep treatment pretreatment filtration device via a transfer pump.

9. The high phosphorus containing fluorine wastewater advanced treatment system according to claim 1, characterized in that: The sludge discharge ports at the bottom of the first sedimentation tank (6) and the second sedimentation tank (8) are connected to the sludge thickening tank (18) via sludge discharge pumps. The sludge thickening tank (18) is connected to the sludge treatment system (19).

10. The high phosphorus containing fluorine wastewater advanced treatment system according to claim 1, characterized in that: The filtration tank (12) is connected to the high-phosphorus and high-fluorine deep treatment resin exchange tower via a transfer pump.

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