Advanced treatment system and method for high-phosphorus fluorine-containing wastewater

Abstract

The invention discloses a high-phosphorus fluorine-containing wastewater advanced treatment system and method.The high-phosphorus fluorine-containing wastewater advanced treatment system comprises a high-phosphorus fluorine-containing wastewater homogenizing pond, a first-stage phosphorus and fluorine removal system, a second-stage advanced treatment system, a water producing pond and a regeneration dosing device, and the first-stage phosphorus and fluorine removal system comprises a reaction system and a first sedimentation pond; the secondary advanced treatment system comprises a pretreatment tank, a second sedimentation tank, a clarification tank, an advanced treatment pretreatment filtering device, a filtering water tank and a high-fluorine advanced treatment resin exchange tower which are connected in sequence, and a high-phosphorus fluorine-containing wastewater homogenizing tank is connected with an inlet of the reaction system; a water outlet of the reaction system is sequentially connected with the first sedimentation tank, the secondary advanced treatment system and the water producing tank, an unqualified water producing port of the clarification tank is connected with the high-phosphorus fluorine-containing wastewater homogenizing tank, and a water outlet of the high-fluorine advanced treatment resin exchange tower is connected with a washing and regeneration water inlet main pipeline. When the method is used for treating the phosphorus-containing and fluorine-containing wastewater generated in electronic chip manufacturing, the phosphorus and fluorine removal rate reaches 99% or above.

Description

Technical Field

[0001] The present invention relates to the field of wastewater treatment technology, and in particular to a system and method for deep treatment of high-phosphorus and fluorine-containing wastewater. Background Art

[0002] In the chip wastewater industry, due to the complex production links, the fluorine-containing wastewater discharged during the manufacturing process is mixed with a large amount of phosphoric acid pollutants. Since the wastewater treatment system only targets fluoride ions, it cannot completely degrade phosphorus, resulting in excessive total discharge phosphorus.

[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. Since the process only targets fluoride, it is difficult to remove fluoride-containing and phosphorus-containing wastewater. Summary of the invention

[0004] The purpose of the present invention is to provide a system and method for deep treatment of high-phosphorus and fluorine-containing wastewater. The system and method are for deep treatment of high-phosphorus and fluorine-containing wastewater generated in the process of electronic chip manufacturing.

[0005] In order to solve the problems existing in the prior art, the technical solution adopted by the present invention is:

[0006] In the first aspect, the present invention provides a high-phosphorus-fluorine-containing wastewater deep treatment system, including a high-phosphorus-fluorine-containing wastewater equalization tank, a primary phosphorus and fluorine removal system and a secondary deep treatment system, a water production tank and a regeneration dosing device, wherein the primary phosphorus and fluorine removal system comprises a reaction system and a first sedimentation tank, wherein the reaction system is used to adjust the pH value of the high-phosphorus-fluorine-containing wastewater, and to add a phosphorus removal agent, CaCl2, PAC and PAM; the secondary deep treatment system comprises a pretreatment tank, a second sedimentation tank, a clarification tank, a deep treatment pretreatment filter device, a filtration tank and a high-fluorine deep treatment resin exchange tower connected in sequence, wherein the high-phosphorus-fluorine-containing wastewater equalization tank and the reaction system are connected in sequence. The inlet of the reaction system is connected to the first sedimentation tank, the outlet of the first sedimentation tank is connected to the pretreatment tank, the second sedimentation tank and the clarification tank in sequence, the qualified water outlet of the clarification tank is connected to the deep treatment pretreatment filtration device, the filtration water tank, the high-fluorine deep treatment resin exchange tower and the water production tank in sequence, the unqualified water outlet of the clarification tank is connected to the high-phosphorus fluoride-containing wastewater tank, the outlet of the high-fluorine deep treatment resin exchange tower is connected to the flushing and regeneration water inlet main pipeline, and the high-fluorine deep treatment resin exchange tower and the regeneration and dosing device are connected through the flushing and regeneration water inlet main pipeline.

[0007] Furthermore, the reaction system includes a pH adjustment tank, a first reaction tank, a second reaction tank, a coagulation tank and a flocculation tank connected in sequence, wherein the pH adjustment tank is used to adjust the pH value of the high-phosphorus fluoride-containing wastewater and add a dephosphorizing agent, the first reaction tank and the second reaction tank are used to adjust the pH value of the high-phosphorus fluoride-containing wastewater and add CaCl2; the coagulation tank is used to adjust the pH value of the high-phosphorus fluoride-containing wastewater, add polyaluminium chloride (PAC) and CaCl2; the flocculation tank is used to add polyacrylamide (PAM). The reaction system adds a dephosphorizing agent, CaCl2, PAC, PAM to the wastewater by adjusting the appropriate pH range required for the reaction, and removes a large amount of phosphate, fluoride, suspended matter and other substances in the water.

[0008] The present invention adjusts the pH of the pH adjustment tank, the first reaction tank, the second reaction tank and the coagulation tank. Even when the water volume is large and the water quality fluctuates greatly, the water quality can be adjusted to a suitable pH value, thereby ensuring the subsequent process.

[0009] Furthermore, the high-fluorine deep treatment resin exchange tower includes an anion bed (phosphate removal tower) and an anion bed (fluorine removal resin tower), and the anion bed (phosphate removal tower) and the anion bed (fluorine removal resin tower) are both filled with ion exchange resins with regeneration ability. Preferably, the ion exchange resins are phosphorus removal ion exchange resins and fluorine removal ion exchange resins.

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

[0011] The secondary deep treatment system is used to add CaCO3, NaHSO3 and defluoridation agent to further reduce the fluoride content in the wastewater and reduce the residual Ca in the reaction system. 2+ , protect SA-1, SA-2 resin, and extend the service life of the resin. SA-1, SA-2 reduce the content of phosphate and fluoride ions in wastewater by ion exchange to meet the discharge requirements.

[0012] In a second aspect, the present invention provides a method for treating high-phosphorus-fluorine-containing wastewater using the high-phosphorus-fluorine-containing wastewater advanced treatment system described in the first aspect, comprising the following steps:

[0013] (1) After the collected high-phosphorus-fluorine-containing wastewater is uniformly mixed in a high-phosphorus-fluorine-containing wastewater homogenization tank, it is sent to a pH adjustment tank to adjust the pH value, and at the same time, a dephosphorization agent is added and stirred to react to remove most of the phosphate in the wastewater, and then the water is discharged into the first reaction tank (2);

[0014] (2) adjusting the pH values ​​of the first reaction tank (2) and the second reaction tank (3) in turn, adding CaCl2 to the first reaction tank and the second reaction tank in turn according to the fluoride ion content, stirring the reaction, and then discharging the water into the coagulation tank (4);

[0015] (3) adjusting the pH value of the coagulation tank (4), adding CaCl2 and polyaluminium chloride into the coagulation tank (4), stirring the reaction, and then discharging the water into the flocculation tank (5);

[0016] (4) adjusting the pH value of the flocculation tank (5), adding polyacrylamide to the flocculation tank (5), and stirring the reaction, the effluent of the flocculation tank (5) flows into the first sedimentation tank (6), the sludge in the first sedimentation tank (6) is discharged into the sludge concentration tank (18), and the supernatant in the first sedimentation tank (6) flows into the pretreatment water tank (7);

[0017] (5) Adding NaHSO3, Na2CO3 and a defluoridant into the pretreatment tank (7), mixing and stirring them evenly, removing oxides in the water and further removing fluorides in the water;

[0018] (6) The effluent from the pretreatment tank 7 passes through the second sedimentation tank (8) and the clarification tank (9) in sequence, and the unqualified produced water flows into the high-phosphorus-containing fluoride wastewater homogenization tank (17); the qualified produced water is filtered through the deep treatment pretreatment filtration device and then enters the filtration tank (12). The effluent from the filtration tank (12) passes through the high-fluorine deep treatment resin exchange tower to remove phosphorus and fluoride pollutants in the wastewater, and finally flows into the production water tank.

[0019] In the present invention, since the dephosphorizing agent is firstly added into the primary dephosphorizing and defluorinating system, and then the defluorinating agent is added into the secondary deep treatment system, the method can further improve the defluorinating effect.

[0020] 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.

[0021] Furthermore, the pH value of the wastewater in the pH adjustment tank (1), the first reaction tank (2), the second reaction tank (3) and the coagulation tank (4) is adjusted to 7.0-7.8, preferably 7.5, by adding NaOH or H2SO4.

[0022] 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 in the amounts described in this application can remove pollutants with maximum efficiency and save costs.

[0023] Furthermore, the ratio of the mass of Ca ions to the mass of 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.

[0024] Furthermore, the ion exchange resin in the high-fluorine deep treatment resin exchange tower is regenerated using a NaOH solution.

[0025] Further, the ion exchange resin in the anion bed (phosphate removal tower) is regenerated using 2-3 BV of a 4-6% by mass NaOH solution, preferably 2.5 BV of a 5% by mass NaOH solution;

[0026] The ion exchange resin in the anion bed (fluorine removal resin tower) is regenerated with 2-3 BV of NaOH solution (pH 12-13) with a mass fraction of 0.04-0.4%, preferably 2.5 BV of NaOH solution with a mass fraction of 0.4%.

[0027] The advantages and beneficial effects of the present invention are:

[0028] The deep treatment system for high-phosphorus and fluoride-containing wastewater of the present invention has a primary phosphorus and fluoride removal system and a secondary deep treatment system, which can remove fluorine and phosphorus together, avoiding the harm of excessive phosphorus. Compared with the traditional chemical precipitation method, the ion exchange method of the present invention produces less sludge, reducing the subsequent sludge treatment cost and environmental impact. In addition, the method can be recycled and reused, with low long-term operating costs, and is suitable for various scenarios such as industrial wastewater treatment.

[0029] The method for deep treatment of high-phosphorus-containing fluoride wastewater produced by electronic chip manufacturing is used to deeply treat phosphorus-containing fluoride wastewater, and phosphorus removal agent, CaCl2, PAC, and PAM are added to remove phosphate and fluoride in the water by flocculation and precipitation. Calcium chloride, CaCl2, and PAC are added to the wastewater. 2+ and F - reaction to generate insoluble CaF2 precipitate; adding phosphorus removal agent calcium hydroxide to the wastewater, Ca 2+ Ions and PO4 3- Ion reaction, generate Ca3(PO4)2 precipitation; add PAC, PAM to the wastewater, coagulation, flocculation reaction, produce precipitation. Add defluoridation agent to the effluent of the primary sedimentation tank, Fe 2+ Ions and F - The ions undergo complexation reaction, further reducing the fluoride content in the wastewater. The reaction formula is as follows:

[0030]

[0031]

[0032] The present invention adopts ion exchange deep treatment technology to remove phosphorus and fluorine pollutants in water, and deeply treats high-phosphorus and fluorine-containing wastewater generated in the process of electronic chip manufacturing, with the phosphorus and fluorine removal efficiency reaching more than 99%. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is a flow chart of a high-phosphorus and fluorine-containing wastewater deep treatment system of the present invention;

[0034] In the figure: 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, filtration tank 12, anion bed (phosphate removal tower) 13, anion bed (fluorine resin removal tower) 14, water production tank 15, lift pump 16, high-phosphorus and fluorine-containing wastewater homogenization tank 17, sludge concentration 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 reflux pump 24;

[0035] Figure 2 This is the SA-1 system operation - water production, regeneration drainage, flushing drainage pipeline diagram, in which: flushing and regeneration water inlet main pipeline 25;

[0036] Figure 3 It is a schematic diagram of the structure of the regeneration dosing device;

[0037] In the figure: NaOH extractor 221, NaOH metering tank 222, NaOH replenishing pipe 223, NaOH storage tank 224. DETAILED DESCRIPTION

[0038] The following will be combined with the drawings in the embodiments of the present application to clearly describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments in the present application belong to the scope of protection of this application.

[0039] The experimental methods in the following examples, unless otherwise specified, are all conventional methods, and are performed according to the techniques or conditions described in the literature in the field or according to the product instructions. The materials, reagents, etc. used in the following examples, unless otherwise specified, can all be obtained from commercial channels.

[0040] Example 1

[0041] like Figure 1 As shown, this embodiment provides a high-phosphorus and fluorine-containing wastewater deep treatment system, including a high-phosphorus and fluorine-containing wastewater equalization tank 17, a primary phosphorus and fluorine removal system, a secondary deep treatment system, a water production tank 15 and a regeneration and dosing device.

[0042] The primary phosphorus and fluorine 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 fluorine-containing wastewater, add phosphorus removal agent, 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 an agitator, which are used to adjust the pH value of the high-phosphorus fluorine-containing wastewater while adding phosphorus removal agent. The first reaction tank 2, the second reaction tank 3 and the coagulation tank 4 are all equipped with a pH meter, a fluoride ion meter (F) and an agitator. The first reaction tank 2, the second reaction tank 3 and the coagulation tank 4 are all used to adjust the pH value of the high-phosphorus fluorine-containing wastewater while adding CaCl2. The coagulation tank 4 is also used to add PAC. The flocculation tank 5 is used to add PAM, which is provided with an agitator. The water inlets of the pH adjustment tank 1, the first reaction tank 2, the second reaction tank 3 and the coagulation tank 4 are all provided with acid adding valves and alkali adding valves.

[0043] The present invention can add NaOH or H2SO4 manually, or can use the multi-stage automatic dosing control device disclosed in the Chinese utility model patent publication number CN 208327501U to add NaOH or H2SO4. The acid adding valve and alkali adding valve used in the present invention are both intelligent control valves, which are commercially available products. The multi-stage automatic dosing control device controls the intelligent control valve according to the measured value of the pH meter to realize the automatic control process of adding acid and alkali.

[0044] The control program of the dosing system is generated by the industrial configuration software INTOUCH system, and other commercially available software can also be used to implement the dosing control process of the present invention, or a manual dosing control process can be used.

[0045] The high-phosphorus and fluorine-containing wastewater homogenization tank 17 is provided with an aeration device, and the high-phosphorus and fluorine-containing wastewater homogenization tank 17 is connected to the pH adjustment tank 1 through a lift pump 16, and a flow meter is provided at the outlet of the lift pump 16. The pH adjustment tank 1 is connected to the first reaction tank 2, the second reaction tank 3, the coagulation tank 4 and the flocculation tank 5 in sequence, the water outlet of the flocculation tank 5 is connected to the first sedimentation tank 6, and the sludge outlet of the first sedimentation tank 6 is connected to the sludge thickening tank 18. The sludge in the sludge thickening tank 18 enters the sludge treatment system 19, and is transported for treatment after dehydration.

[0046] The secondary deep treatment system includes a pretreatment tank 7, a second sedimentation tank 8, a clarification tank 9, a deep treatment pretreatment filter, a filter tank 12 and a high-phosphorus and high-fluorine deep treatment resin exchange tower connected in sequence. The pretreatment tank 7 is used to add NaHSO3, Na2CO3 and defluoridation agent, and the pretreatment tank 7 is equipped with an ORP meter. The deep treatment pretreatment filter includes a multi-media filter (MMF) 10 and an activated carbon filter (ACF) 11. The high-phosphorus and high-fluorine deep treatment resin exchange tower includes an anion bed (phosphate removal tower) 13 (SA-1) and an anion bed (fluorine removal resin tower) 14 (SA-2). SA-1 is filled with a phosphorus removal ion exchange resin with regeneration ability. In this embodiment, Dusheng ion exchange resin A-107 is used; SA-2 is filled with a fluorine removal ion exchange resin with regeneration ability. In this embodiment, Tulsion CH-35 ion exchange resin is used.

[0047] 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 water outlet weir at the upper end of the second sedimentation tank 8 is connected to the clarification tank 9, the sludge outlet set at the bottom of the second sedimentation tank 8 is connected to the sludge concentration tank 18, and the sludge in the sludge concentration tank enters the sludge treatment system and is transported out for treatment after dehydration. The clarification tank 9 is equipped with a fluoride ion meter (F) and a total phosphorus online detector (TP). The unqualified water outlet of the clarification tank 9 is connected to the high-phosphorus fluoride wastewater and pool 17 through a delivery pump, and the qualified water outlet of the clarification tank 9 is connected to MMF10 and ACF11 in turn through a delivery pump, and the outlet of ACF11 is connected to the filter water tank 12.

[0048] like Figure 2 As shown, the water outlet of the filter water pool 12 is connected to the water inlet manifold at the top of SA-1 through a delivery pump, a water inlet valve AV-SA1-01, and a water inlet pipe. The water production manifold at the bottom of SA-1 is connected to the water inlet manifold at the top of SA-2 through a water production valve AV-SA1-02; the water production manifold at the bottom of SA-2 is connected to the water production pool 15. The water production pool 15 is equipped with a pH meter, a fluoride ion meter (F) and a total phosphorus online detector (TP). The water production port of the water production pool 15 is respectively connected to the SA-2 regeneration pump 20, the SA-1 regeneration pump 21, the unqualified return pipeline, the reclaimed water reuse pipeline and the qualified discharge pipeline. The unqualified return pipeline is connected to the water inlet of the filter water pool, and an unqualified return pump 24 is arranged on the unqualified return pipeline. The recycled water reuse pipeline is connected to the pure water system filter pool. The filter pool is part of the pure water pretreatment system. It is the water production pool after the raw water is filtered by MMF to remove insoluble matter and colloids in the water. It is mixed with the filtered raw water for use.

[0049] The water outlet of the SA-1 regeneration pump 21 is connected to the main flushing and regeneration water inlet pipeline 25, and a regeneration dosing device 23 is arranged on the main flushing and regeneration water inlet pipeline 25. The water outlet of the main flushing and regeneration water inlet pipeline 25 is respectively connected to the forward wash water inlet pipeline and the backwash, flushing and regeneration water inlet pipeline. The forward wash water inlet pipeline is connected to the top water inlet manifold of the SA-1 regeneration pump through the forward wash water inlet valve AV-SA1-03; the bottom water production manifold of the SA-1 regeneration pump is connected to the forward wash drainage pipeline through the forward wash drainage valve AV-SA1-04, and the forward wash drainage pipeline is connected to the high-phosphorus and fluorine-containing pool.

[0050] The backwash, flushing and regeneration water inlet pipelines are connected to the regeneration pipeline and backwash pipeline respectively. The regeneration pipeline is connected to the SA-1 bottom water production manifold through the regeneration water inlet valve AV-SA1-05, and the backwash pipeline is connected to the SA-1 bottom water production manifold through the regeneration backwash valve AV-SA1-07. The SA-1 top water inlet manifold is connected to the backwash, flushing and regeneration drainage pipelines through the regeneration and backwash drainage valve AV-SA1-06, and the backwash, flushing and regeneration drainage pipelines are connected to the high phosphorus and fluoride pool.

[0051] The pipeline connection of the SA-2 regeneration pump 20 is the same as that of the SA-1 regeneration pump 21. The water outlet of the SA-2 regeneration pump 20 is connected to the flushing and regeneration water inlet main pipeline 25, on which a regeneration dosing device 22 is provided. The water outlet of the flushing and regeneration water inlet main pipeline 25 is respectively connected to the forward wash water inlet pipeline and the backwash, flushing and regeneration water inlet pipeline. The forward wash water inlet pipeline is connected to the SA-2 top water inlet manifold through the forward wash water inlet valve; the water production manifold at the bottom of the SA-2 regeneration pump is connected to the forward wash drainage pipeline through the forward wash drainage valve, and the forward wash drainage pipeline is connected to the high phosphorus and fluoride-containing pool.

[0052] The backwash, flushing and regeneration water inlet pipelines are connected to the regeneration pipeline and backwash pipeline respectively. The regeneration pipeline is connected to the water production manifold at the bottom of the SA-2 regeneration pump through the regeneration water inlet valve, and the backwash pipeline is connected to the water production manifold at the bottom of the SA-2 regeneration pump through the regeneration backwash valve. The top water inlet manifold of the SA-2 regeneration pump is connected to the backwash, flushing and regeneration drainage pipelines through the regeneration and backwash drainage valves, and the backwash, flushing and regeneration drainage pipelines are connected to the high-phosphorus and fluoride pools.

[0053] like Figure 3As shown, the regeneration dosing device 23 includes a NaOH extractor 221, a NaOH metering tank 222, a NaOH replenishing pipe 223 and a NaOH storage tank 224. The NaOH storage tank 224 is connected to the NaOH metering tank 222 through the NaOH replenishing pipe 223 and the delivery pump, and the NaOH solution in the NaOH storage tank is delivered to the NaOH metering tank through the delivery pump; 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 of the NaOH metering tank 222 through the regeneration alkali injection valve AV-SA1-08, and the other end is connected to the flushing and regeneration water inlet main pipeline 25. The NaOH storage tank 224 stores a 30% NaOH solution by mass.

[0054] The regeneration dosing device 22 and the regeneration dosing device 23 have the same structure.

[0055] Taking SA-1 regeneration pump 21 as an example, the steps are as follows:

[0056] 1) Operation: Open the water production valve AV-SA1-02 and the water inlet valve AV-SA1-01, close other valves, and start the filter pool delivery pump;

[0057] 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;

[0058] 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;

[0059] 4) Regeneration: Open the backwash and regeneration drain valve AV-SA1-06, the regeneration water inlet valve AV-SA1-05, and the regeneration alkali injection valve AV-SA1-08, close other valves, and start the SA-1 regeneration pump.

[0060] Example 2

[0061] like Figure 1 As shown, the method for deeply treating high-phosphorus-fluorine-containing wastewater using the high-phosphorus-fluorine-containing wastewater deep treatment system described in Example 1 comprises the following steps:

[0062] This embodiment is to deeply treat the high-phosphorus and fluoride-containing wastewater generated by electronic chip manufacturing. The main pollutants in the high-phosphorus and fluoride-containing wastewater generated by electronic chip manufacturing are phosphate and fluoride.

[0063] (1) High-phosphorus-fluorine-containing wastewater is collected through the high-phosphorus-fluorine-containing wastewater homogenization tank 17. After testing, the phosphate concentration in the wastewater is 150 mg / L and the fluorine concentration is 600 mg / L. The wastewater in the tank is stirred and mixed evenly by the aeration device set in the high-phosphorus-fluorine-containing wastewater homogenization tank 17. It is pumped into the pH adjustment tank 1 through the lifting pump 16. In the pH adjustment tank 1, NaOH or H2SO4 is added to adjust the pH value to 7.5. At the same time, a dephosphorizing agent is added and stirred for 30 minutes to remove most of the phosphate in the wastewater and then flow into the first reaction tank 2. The dephosphorizing agent selected in this embodiment is calcium salt Ca(OH)2. The amount of dephosphorizing agent added is based on the average value of the total phosphorus detection value of the high-phosphorus-fluorine-containing wastewater homogenization tank after continuous operation for 15 days, and the amount of calcium ion added is 300ppm.

[0064] (2) In the first reaction tank 2, NaOH or H2SO4 was added to adjust the pH value to 7.5, CaCl2 was added to the first reaction tank 2 according to the fluoride ion content, and the reaction was stirred for 30 minutes. The ratio of the mass of Ca ions to the mass of fluoride ions (kg / h) in the first reaction tank 2 was 19:12.

[0065] (3) The effluent from the first reaction tank 2 flows into the second reaction tank 3. NaOH or H2SO4 is added to the second reaction tank 3 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 ratio of the mass of Ca ions to the mass of fluoride ions (kg / h) in the second reaction tank 3 is 19:12. After testing, the effluent phosphorus of the second reaction tank 3 is <5mg / L, and the fluorine is <25mg / L. The effluent from the second reaction tank 3 flows into the coagulation tank 4.

[0066] (4) In the coagulation tank 4, NaOH or H2SO4 is added to adjust the pH value to 7.5. At the same time, CaCl2 is added to the coagulation tank 4 according to the fluoride ion content, and the reaction is stirred for 30 minutes. The ratio of the mass of Ca ions to the mass of fluoride ions (kg / h) in the coagulation tank 4 is 19:12.

[0067] (5) PAC was added into the coagulation tank 4 at a dosage of 150 mg / L. The mixture was stirred evenly. After reacting for 30 min, the effluent from the coagulation tank 4 flowed into the flocculation tank 5.

[0068] (6) Add PAM to flocculation tank 5 and stir evenly. React for 30 minutes. The PAM dosage is 8 ppm.

[0069] (7) Then the effluent of the flocculation tank 5 flows into the first sedimentation tank 6, where the mud and water are separated by gravity, and the sludge settles to the bottom. The sludge deposited at the bottom is discharged into the sludge concentration tank 18 through the sludge discharge pump, and the sludge is dehydrated by the sludge treatment system 19 and then transported for treatment. The supernatant overflows to the pretreatment water tank 7 through the effluent weir of the first sedimentation tank 6; after testing, the effluent of the first sedimentation tank 6 has a phosphorus content of less than 3 mg / L and a fluorine content of less than 15 mg / L.

[0070] (8) Add NaHSO3, Na2CO3 and defluorinating agent to the pretreatment tank 7, mix and stir, remove oxides in the water and further remove fluorides in the water. The defluorinating agent is an iron salt defluorinating agent. In this embodiment, polyferric sulfate is used, which has low cost, good treatment effect and wide application range. The addition of NaHSO3 is controlled according to the reading of the ORP meter to ensure that the oxidation-reduction potential (ORP) is less than 150mv; the addition amount of the defluorinating agent is 100ppm; the addition amount of Na2CO3 is 100ppm.

[0071] (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 concentration tank 18 through the sludge discharge pump. The sludge is dehydrated by the sludge treatment system 19 and then transported for treatment. According to the test, the effluent of the second sedimentation tank 8 has phosphorus <3mg / L, fluorine <5mg / L, and ORP <150mv.

[0072] (10) The wastewater flowing into the clarification tank 9 controls the outlet switching valve according to the detection value of the sedimentation tank instrument. The unqualified produced water is returned to the high-phosphorus and fluorine-containing wastewater equalization tank 17 through the delivery pump. The qualified produced water is filtered through the multi-media filter (MMF) 10 and the activated carbon filter (ACF) 11 in turn and then enters the filtration pool 12. After testing, the effluent SDI of the deep treatment pretreatment filtration device is <3.5; the effluent of the filtration pool flows into the anion bed (phosphate removal tower) (SA-1) 13 and the anion bed (fluorine removal resin tower) (SA-2) 14 in turn. The resin tower is filled with ion exchange resin, which can effectively remove phosphorus and fluorine pollutants in the wastewater, and finally flows into the water production pool 15.

[0073] The water produced in the water production pool is detected according to the data of the online detection instrument F meter and TP meter. When the total phosphorus>0.5mg / L fluoride>1mg / L, the unqualified reflux pump 24 is turned on to pump the unqualified water in the water production pool into the filtration pool 12 for further treatment. After testing, the water quality of the produced water obtained by the equipment and method of the present invention can reach total phosphorus<0.5mg / L fluoride<1mg / L. When the total phosphorus<0.5mg / L fluoride<1mg / L, according to the demand for reuse of reclaimed water, when the water production is less than the reuse demand, all the produced water is reused; when the water production is greater than the reuse demand, the excess produced water is discharged through a qualified discharge pipeline for treatment.

[0074] The wastewater treated by the process of the present invention meets the discharge standard of Class III water quality of surface water standard in the "Surface Water Environmental Quality Standard" (GB 3838-2002), thus achieving environmentally friendly discharge in the electronic chip industry.

[0075] The removal rates of phosphate and fluoride are calculated using the following formula:

[0076] The removal rate of phosphate is: (1-0.5 / 150)*100%>99%;

[0077] The removal rate of fluorine is: (1-1 / 600)*100%>99%.

[0078] It is known from calculation that the phosphorus and fluorine removal rates can reach over 99% by using the treatment system and method of the present invention.

[0079] Furthermore, the ion exchange resin has a regeneration function. The ion exchange resin in the SA-1 regeneration pump 21 is regenerated with a NaOH solution with a mass fraction of 5%, and the ion exchange resin in the SA-2 regeneration pump 20 is regenerated with a NaOH solution with a mass fraction of 0.4%. The dosage of the 5% NaOH solution and the 0.4% NaOH solution is 2.5BV (BV is the resin volume). The NaOH storage tank 224 stores a 30% NaOH solution by mass. The NaOH metering tank is used to measure the amount of NaOH required for regeneration, and the amount is based on the amount of NaOH solution required for a single regeneration; the amount of NaOH solution required for a single regeneration using a 30% NaOH solution is 0.417BV (BV resin solvent), and the ratio of the amount of 5% NaOH solution to 30% NaOH required for a single regeneration is 6:1.

[0080] 1) SA-1 regeneration pump regeneration method: use 5% NaOH solution, 4BV / H flow rate, regeneration time 30-60min; backwash water: pure water / soft water / tap water, backwash flow rate: 5-10BV / H, backwash time 30min.

[0081] 2) SA-2 regeneration pump regeneration method: using 0.4% NaOH solution (pH12-13) at a flow rate of 2-4BV / H, regeneration time 30-60min; backwash water: pure water / soft water / tap water, backwash flow rate: 4-6BV / H, backwash time 30min.

[0082] The embodiments of the present application are described above in conjunction with the accompanying drawings, but the present application is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of the present application, ordinary technicians in this field can also make many forms without departing from the purpose of the present application and the scope of protection of the claims, all of which are within the protection of the present application.

Claims

1. A high-phosphorus and fluorine-containing wastewater deep treatment system, characterized by: The invention comprises a high-phosphorus-fluorine-containing wastewater homogenization tank (17), a primary phosphorus- and fluorine-removing system and a secondary deep treatment system, a water production tank (15) and a regeneration dosing device. The primary phosphorus- and fluorine-removing system comprises a reaction system and a first sedimentation tank (6). The reaction system is used to adjust the pH value of the high-phosphorus-fluorine-containing wastewater and to add a phosphorus removal agent, CaCl2, polyaluminium chloride and polyacrylamide. The secondary deep treatment system comprises a pretreatment tank (7), a second sedimentation tank (8), a clarification tank (9), a deep treatment pretreatment filter, a filtration tank (12) and a high-fluorine deep treatment resin exchange tower which are connected in sequence. The high-phosphorus-fluorine-containing wastewater homogenization tank (17) is connected to the inlet of the reaction system, and the outlet of the reaction system is connected to the inlet of the reaction system. The device is connected to the first sedimentation tank (6); the outlet of the first sedimentation tank (6) is connected to the pretreatment tank (7), the second sedimentation tank (8), and the clarification tank (9) in sequence; the qualified water outlet of the clarification tank (9) is connected to the deep treatment pretreatment filtration device, the filtration water tank (12), the high-fluorine deep treatment resin exchange tower, and the water production tank (15) in sequence; the unqualified water outlet of the clarification tank (9) is connected to the high-phosphorus fluorine-containing wastewater and tank (17); the outlet of the high-fluorine deep treatment resin exchange tower is connected to the flushing and regeneration water inlet main pipeline (25); the high-fluorine deep treatment resin exchange tower is connected to the regeneration and dosing device through the flushing and regeneration water inlet main pipeline (25).

2. A high-phosphorus and fluorine-containing wastewater deep treatment system according to claim 1, characterized in that: The reaction system comprises a pH regulating tank (1), a first reaction tank (2), a second reaction tank (3), a coagulation tank (4) and a flocculation tank (5) which are connected in sequence. The pH regulating tank (1) is used to adjust the pH value of the high-phosphorus fluorine-containing wastewater and add a dephosphorizing agent. The first reaction tank (2) and the second reaction tank (3) are used to adjust the pH value of the high-phosphorus fluorine-containing wastewater and add CaCl2; the coagulation tank (4) is used to adjust the pH value of the high-phosphorus fluorine-containing wastewater and add polyaluminium chloride and CaCl2; and the flocculation tank is used to add polyacrylamide.

3. The high-phosphorus and fluorine-containing wastewater deep treatment system according to claim 1 is characterized in that: The high-fluorine deep treatment resin exchange tower is filled with ion exchange resin with regeneration capability.

4. The high-phosphorus and fluorine-containing wastewater deep treatment system according to claim 1 is characterized in that: The regeneration dosing device comprises a NaOH extractor (221), a NaOH metering tank (222), a NaOH replenishing pipe (223) and a NaOH storage tank (224); the NaOH storage tank (224) and the NaOH metering tank (222) are connected via the NaOH replenishing pipe (223); one end of the NaOH extractor (221) is connected to the bottom drug outlet pipe of the NaOH metering tank (222) via a regeneration alkali injection valve, and the other end is connected to the flushing and regeneration water inlet main pipeline (25).

5. A method for treating high-phosphorus-fluorine-containing wastewater using the high-phosphorus-fluorine-containing wastewater deep treatment system according to any one of claims 1 to 4, characterized in that: The following steps are involved: (1) After the collected high-phosphorus-fluorine-containing wastewater is uniformly mixed in a high-phosphorus-fluorine-containing wastewater homogenization tank (17), the wastewater is sent to a pH adjustment tank (1) to adjust the pH value, a dephosphorization agent is added, the reaction is stirred, and the water is discharged into a first reaction tank (2); (2) adjusting the pH values ​​of the first reaction tank (2) and the second reaction tank (3) in turn, adding CaCl2 and stirring the reaction, and then discharging the water into the coagulation tank (4); (3) adjusting the pH value of the coagulation tank (4), adding CaCl2 and polyaluminium chloride to the coagulation tank (4), stirring the reaction, and then discharging the water into the flocculation tank (5); (4) adjusting the pH value of the flocculation tank (5), adding polyacrylamide to the flocculation tank (5), and stirring the reaction, the effluent of the flocculation tank (5) flows into the first sedimentation tank (6), the sludge in the first sedimentation tank (6) is discharged into the sludge concentration tank (18), and the supernatant in the first sedimentation tank (6) flows into the pretreatment water tank (7); (5) Adding NaHSO3, Na2CO3 and a defluorinating agent into the pretreatment tank (7), and mixing and stirring them uniformly; (6) The effluent from the pretreatment tank 7 passes through the second sedimentation tank (8) and the clarification tank (9) in sequence, and the unqualified produced water flows into the high-phosphorus-containing fluoride wastewater homogenization tank (17); the qualified produced water is filtered through the deep treatment pretreatment filtration device and then enters the filtration tank (12), and the effluent from the filtration tank (12) passes through the high-fluorine deep treatment resin exchange tower and flows into the water production tank (15).

6. The processing method according to claim 5, characterized in that: The reaction time of the pH adjustment tank (1), the first reaction tank (2), the second reaction tank (3), the coagulation tank (4) and the flocculation tank (5) are all ≥25 minutes.

7. The processing method according to claim 5, characterized in that: The pH values ​​of the wastewater in the pH adjustment tank (1), the first reaction tank (2), the second reaction tank (3) and the coagulation tank (4) are all adjusted to 7.0-7.

8.

8. The processing method according to claim 5, characterized in that: The amount of polyaluminium chloride added to the coagulation tank (4) is 150-200 mg / L; the amount of polyacrylamide added to the flocculation tank (5) is 6-10 mg / L.

9. The processing method according to claim 5, characterized in that: The mass ratio of Ca ions to fluoride ions in the first reaction tank (2), the second reaction tank (3) and the coagulation tank (4) is 19:10-13.

10. The processing method according to claim 5, characterized in that: The ion exchange resin in the high-fluorine deep treatment resin exchange tower is regenerated by using NaOH solution.

Images