Treatment system for nano-zirconia toughened ceramic powder production sewage

Abstract

The utility model discloses a treatment system for nano-zirconia toughened ceramic powder production sewage. The treatment system comprises a first mixing tank for collecting low-alcohol-content wastewater and a second mixing tank for collecting high-alcohol-content wastewater, a vibrating membrane, a vibrating membrane water production tank and a diluted alcohol tower are sequentially arranged in the water outlet direction of the first mixing tank; a concentrated alcohol tower is arranged in the water outlet direction of the second mixing tank; gas phases of the diluted alcohol tower and the concentrated alcohol tower sequentially enter a deamination tower and an ammonia absorption tower, and a liquid phase of the deamination tower sequentially enters a flash tank and a vaporization film; liquid phases of the diluted alcohol tower and the concentrated alcohol tower enter a sewage adjusting tank, a filtering system and a high-pressure reverse osmosis membrane concentration system are sequentially arranged in the water outlet direction of the sewage adjusting tank, high-pressure reverse osmosis membrane produced water enters a low-pressure reverse osmosis membrane concentration system, and low-pressure reverse osmosis produced water is discharged. According to the device disclosed by the utility model, alcohol extraction and deamination, membrane concentration and evaporative crystallization are adopted, and the recovered zirconium hydroxide, ethanol and ammonia water can be directly reused for production, so that the problem of high salinity in sewage is solved, and the water production guarantee rate is improved.

Description

Technical Field

[0001] This utility model relates to the field of wastewater treatment technology, specifically to a treatment system for wastewater from the production of nano-zirconia toughened ceramic powder. Background Technology

[0002] Nano-zirconia toughened ceramic powder is a powder material that can be used to produce ceramic substrates with high mechanical properties. Due to its characteristics such as no signal shielding, high hardness, strong appearance, and excellent heat dissipation similar to metallic materials, it can greatly meet the needs of electronic signal transmission and has become a new material used in information networks. Nanoparticle materials applied in the electronics industry are an emerging materials industry in China, including nano-silica low-dielectric powder, nano-zirconia toughened ceramic powder, and nano-composite stable dielectric ceramic powder. Under the leadership of academicians of the Chinese Academy of Sciences, its domestic production has begun to show results. Currently, there is no fixed treatment process for the wastewater from its production (mainly the reaction liquid, washing water, and ethanol washing liquid of nano-zirconia toughened ceramic powder). The production process of this material produces a reaction liquid, and the powder needs to undergo multiple stages of water washing and alcohol washing. The discharged wastewater contains a high concentration of ethanol (low-ethanol wastewater contains ≈8% ethanol, high-ethanol wastewater contains ≈80% ethanol), heavy metal ions, organic acids and organic acid ammonium salts, ammonium chloride, etc. After alcohol removal, the TDS is ≈35000 mg / L.

[0003] High concentrations of ethanol and ammonia in waste liquid have recycling value and can be reused in production. Apart from ethanol, other organic substances that exhibit COD are organic acids or organic acid salts.

[0004] The wastewater treatment and discharge standards generally need to meet the indirect or direct discharge standards of the "Emission Standard of Pollutants for Inorganic Chemical Industry" (GB 31573-2015). Currently, most river basins have put forward salt control requirements, which are based on local environmental protection standards. Most high-salinity wastewater needs to undergo desalination treatment before it can be discharged into downstream wastewater treatment plants or directly into the river basin.

[0005] Some water quality indicators are shown in Table 1:

[0006] Table 1. Limits for Water Pollutant Discharge

[0007] Unit: mg / L (except pH value)

[0008]

[0009] A zirconia powder production company uses a combined process of "coagulation sedimentation + biological treatment + membrane separation" to treat low-concentration wastewater. First, coagulation sedimentation removes suspended solids and most organic matter from the wastewater. Then, activated sludge biological treatment further removes organic matter and nutrients such as nitrogen and phosphorus. Finally, membrane separation removes recalcitrant organic matter and heavy metal ions from the wastewater. After treatment, the wastewater meets national discharge standards. However, this method is only suitable for low-concentration wastewater treatment and does not address the treatment of high-concentration wastewater. It follows the conventional water treatment route of first chemical treatment followed by membrane concentration, failing to consider the specific characteristics of the wastewater from this production process. Relying on biochemical removal to replace organic acid ions with inorganic anions increases the organic matter treatment load without reducing the desalination load of the membrane separation system.

[0010] A research institution used a combined process of "chemical oxidation + activated carbon adsorption" to treat the aforementioned wastewater. First, potassium permanganate was used as an oxidant to oxidize the organic matter in the wastewater into harmless substances. Then, activated carbon adsorption was used to remove residual organic matter and heavy metal ions from the wastewater. This treatment system relied entirely on the oxidant to oxidize organic acids and ethanol in the water, resulting in high oxidant and activated carbon consumption, and the generation of waste activated carbon. Furthermore, the treated water did not address the problems of high salinity and high ammonia nitrogen levels. Utility Model Content

[0011] To address the shortcomings of existing technologies, this utility model provides a wastewater treatment system for the production of nano-zirconia toughened ceramic powder, so as to achieve resource recovery and compliant discharge treatment of wastewater from the production of nano-zirconia toughened ceramic powder.

[0012] This utility model discloses a treatment system for wastewater from the production of nano-zirconia toughened ceramic powder. The wastewater includes reaction liquid, washing water, and alcohol washing water. The reaction liquid and washing water are low-alcohol wastewater (ethanol content less than 15%), and the alcohol washing water is high-alcohol wastewater (ethanol content greater than 75%). The system includes a first mixing tank for collecting low-alcohol wastewater and a second mixing tank for collecting high-alcohol wastewater.

[0013] After ammonia neutralization and zirconium removal are completed in the first mixing tank, a vibrating membrane, a vibrating membrane product water tank, and a dilute alcohol tower are sequentially installed in the water outlet direction of the first mixing tank; after alkali mixing is completed in the second mixing tank, a concentrated alcohol tower is installed in the water outlet direction of the second mixing tank.

[0014] The gas phases from both the dilute alcohol tower and the concentrated alcohol tower enter the ammonia removal tower. The gas phase from the ammonia removal tower enters the ammonia absorption tower. The liquid phase from the ammonia removal tower sequentially enters the flash tank and the vaporization membrane. The dilute alcohol side of the vaporization membrane is connected to the dilute alcohol tower.

[0015] The liquid phases from both the dilute alcohol tower and the concentrated alcohol tower enter the wastewater equalization tank. The wastewater equalization tank is equipped with a filtration system and a high-pressure reverse osmosis membrane concentration system in sequence at the outlet direction. The concentrated water from the high-pressure reverse osmosis membrane concentration system enters the evaporator crystallizer, and the mother liquor from the evaporator crystallizer enters the mother liquor dryer. The permeate from the high-pressure reverse osmosis membrane concentration system enters the low-pressure reverse osmosis membrane concentration system, and the concentrated water from the low-pressure reverse osmosis membrane concentration system returns to the high-pressure reverse osmosis membrane concentration system. The permeate from the low-pressure reverse osmosis membrane concentration system, the evaporator crystallizer, and the condensate from the mother liquor dryer are discharged.

[0016] As a further improvement of this utility model, an ammonia dosing system is connected to the first mixing tank, a sodium hydroxide dosing system is connected to the vibrating membrane permeate tank and the second mixing tank, and a hydrochloric acid dosing system is connected to the wastewater equalization tank; wherein, the ammonia dosing system, the sodium hydroxide dosing system, and the hydrochloric acid dosing system all include dosing tanks, and the dosing tanks are connected to the dosing ports of the first mixing tank, the vibrating membrane permeate tank, the second mixing tank, or the wastewater equalization tank via dosing pipelines, and the dosing pipelines are equipped with corresponding valves and flow meters, etc., to supply the first mixing tank with... Ammonia (preferably 25% ammonia) is added to the low-alcohol wastewater to adjust the pH value, precipitate zirconium ions, and then the powder is concentrated step by step using a columnar vibrating ultrafiltration membrane. After concentration, the high-purity powder is recovered by pressure filtration and finally returned to the production process. Sodium hydroxide (preferably 32% sodium hydroxide) is added to the second mixing tank, and the alcohol wash water is alkali-added and then fed into the concentrated alcohol tower for distillation to remove alcohol and ammonia. Sodium hydroxide (preferably 32% sodium hydroxide) is added to the vibrating membrane product water tank, and the waste liquid in the vibrating membrane product water tank is alkali-added and then fed into the dilute alcohol tower for distillation to remove alcohol and ammonia. Hydrochloric acid is added to the wastewater equalization tank for mixing, homogenization and equalization.

[0017] As a further improvement of this utility model, the liquid phase of the deammoniation tower is dilute ethanol. After the liquid phase of the deammoniation tower is dehydrated and concentrated by the flash tank and the vaporization membrane, concentrated ethanol is output from the concentrated water meter of the vaporization membrane.

[0018] As a further improvement of this utility model, the filtration system includes a multi-media filter, a bag filter, and a first intermediate water tank arranged sequentially along the sewage treatment direction; wherein, the backwash water of the multi-media filter enters the sewage equalization tank, the backwash water of the first intermediate water tank enters the multi-media filter, and the concentrate of the low-pressure reverse osmosis membrane concentration system returns to the first intermediate water tank.

[0019] As a further improvement of this utility model, a second intermediate water tank is provided between the high-pressure reverse osmosis membrane concentration system and the low-pressure reverse osmosis membrane concentration system. The permeate from the high-pressure reverse osmosis membrane concentration system first enters the second intermediate water tank and then enters the low-pressure reverse osmosis membrane concentration system. A reverse osmosis concentrate tank is provided between the high-pressure reverse osmosis membrane concentration system and the evaporator crystallizer. The concentrate from the high-pressure reverse osmosis membrane concentration system first enters the reverse osmosis concentrate tank and then enters the evaporator crystallizer. The impurities produced by the evaporator crystallizer and the mother liquor dryer are recovered.

[0020] As a further improvement of this utility model, the product water of the low-pressure reverse osmosis membrane concentration system, the evaporation condensate of the evaporator crystallizer and the mother liquor dryer enter the first product water tank, and the effluent of the first product water tank is indirectly discharged; or, the effluent of the first product water tank enters the A / O biochemical system and the second product water tank in sequence, and the effluent of the second product water tank is directly discharged.

[0021] As a further improvement of this utility model, the evaporator crystallizer is an MVR evaporator crystallizer, a multi-effect evaporator crystallizer, or a single-effect evaporator crystallizer; the high-pressure reverse osmosis membrane concentration system is a combination of a STRO membrane and a DTRO membrane, or a combination of an MTRO membrane and a DTRO membrane.

[0022] As a further improvement of this utility model, the A / O biochemical system is a combination of an A / O tank and a secondary sedimentation tank, or a combination of an A / O tank and an MBR membrane.

[0023] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0024] This invention fully considers the characteristics of wastewater from the production of nanopowder materials and has a thorough understanding of its components. While ensuring water quality meets standards, it maximizes resource recovery. The main process adopts either "alcohol extraction and ammonia removal + membrane concentration + evaporation crystallization" or "alcohol extraction and ammonia removal + membrane concentration + evaporation crystallization + biochemical treatment." The recovered zirconium hydroxide, ethanol, and ammonia can be directly reused in production, solving the problem of high salinity in wastewater and improving the water production guarantee rate. This invention reduces the organic matter and ammonia nitrogen load of the subsequent biochemical process through pre-membrane separation. The organic matter concentration after membrane separation is less than 200 mg / L, which can meet the indirect discharge standard. It eliminates the impact of high salinity on the biochemical system and ensures that the biochemical effluent consistently meets standards. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the wastewater treatment system for the production of nano-zirconia toughened ceramic powder disclosed in this utility model.

[0026] Figure 2 This is a schematic diagram of the wastewater treatment method for the production of nano-zirconia toughened ceramic powder disclosed in this utility model.

[0027] In the picture:

[0028] 1. First mixing tank; 2. Vibrating membrane; 3. Vibrating membrane permeate tank; 4. Second mixing tank; 5. Dilute alcohol tower; 6. Concentrated alcohol tower; 7. Ammonia removal tower; 8. Ammonia absorption tower; 9. Flash tank; 10. Vaporizing membrane; 11. Wastewater equalization tank; 12. Multi-media filter; 13. Bag filter; 14. First intermediate water tank; 15. High-pressure reverse osmosis membrane concentration system; 16. Second intermediate water tank; 17. Low-pressure reverse osmosis membrane concentration system; 18. First permeate tank; 19. A / O biochemical system; 20. Second permeate tank; 21. Reverse osmosis concentrate tank; 22. Evaporator crystallizer; 23. External discharge mother liquor tank; 24. Mother liquor dryer. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0030] The present invention will now be described in further detail with reference to the accompanying drawings:

[0031] like Figure 1 As shown, this utility model provides a treatment system for wastewater from the production of nano-zirconia toughened ceramic powder. This wastewater is generated during the production of nano-zirconia toughened ceramic powder in the inorganic chemical industry. The main components of this wastewater are high-concentration ethanol, zirconium ions, organic acids, and ammonium salts of organic acids, with ammonium oxalate being the primary organic acid. The wastewater includes reaction clarified liquid, washing water, and alcohol washing water. The reaction clarified liquid and washing water are low-ethanol-content wastewater (ethanol content less than 15%), while the alcohol washing water is high-ethanol-content wastewater (ethanol content greater than 75%). The treatment system of this utility model includes a first mixing tank. 1. Vibrating membrane; 2. Vibrating membrane permeate tank; 3. Second mixing tank; 4. Dilute alcohol tower; 5. Concentrated alcohol tower; 6. Ammonia removal tower; 7. Ammonia absorption tower; 8. Flash tank; 9. Vaporization membrane; 10. Wastewater equalization tank; 11. Multi-media filter; 12. Bag filter; 13. First intermediate water tank; 14. High-pressure reverse osmosis membrane concentration system; 15. Second intermediate water tank; 16. Low-pressure reverse osmosis membrane concentration system; 17. First permeate tank; 18. A / O biochemical system; 19. Second permeate tank; 20. Reverse osmosis concentrate tank; 21. Evaporator crystallizer; 22. External discharge mother liquor tank; 23. Mother liquor dryer; 24. Specifically:

[0032] The first mixing tank 1 is used to collect low-alcohol wastewater. An ammonia dosing system is connected to the first mixing tank 1, and the dosing tank is connected to the dosing port of the first mixing tank 1 via a dosing pipeline equipped with corresponding valves and flow meters. Ammonia (preferably 25% ammonia) is added to the low-alcohol wastewater in the first mixing tank 1 to adjust the pH value and precipitate zirconium ions. The outlet of the first mixing tank 1 is connected to the inlet of the vibrating membrane 2, and the outlet of the vibrating membrane 2 is connected to the inlet of the vibrating membrane permeate tank 3. After the zirconium ions are neutralized and precipitated in the first mixing tank 1, the powder is then concentrated stage by stage using a columnar vibrating ultrafiltration membrane. The concentrated high-purity powder is then recovered by pressure filtration and ultimately returned to the production process. The effluent from the vibrating membrane 2 is collected in the vibrating membrane permeate tank 3. The vibrating membrane product tank 3 is equipped with a sodium hydroxide dosing system, which has the same structure as the ammonia dosing system. The outlet of the vibrating membrane product tank 3 is connected to the inlet of the dilute alcohol tower 5. Sodium hydroxide (preferably 32% sodium hydroxide) is added to the vibrating membrane product tank. After adding alkali solution, the waste liquid in the vibrating membrane product tank enters the dilute alcohol tower 5 for distillation to remove alcohol and ammonia.

[0033] The second mixing tank 4 is used to collect high-alcohol-content wastewater. The second mixing tank 4 is equipped with a sodium hydroxide dosing system, which has the same structure as the ammonia dosing system. The outlet of the second mixing tank 4 is connected to the inlet of the concentrated alcohol tower 6. Sodium hydroxide (preferably 32% sodium hydroxide) is added to the second mixing tank 4. After adding alkali, the alcohol wash water enters the concentrated alcohol tower 6 for distillation to remove alcohol and ammonia.

[0034] Dilute ethanol tower 5 and concentrated ethanol tower 6 are used for distillation to control the ethanol content in the liquid phase to be below 50 mg / L. The vapor phases from both dilute ethanol tower 5 and concentrated ethanol tower 6 enter ammonia stripping tower 7. Ammonia stripping tower 7 recovers ethanol from the distilled liquid phase, and the vapor phase enters ammonia absorption tower 8 to recover ammonia water with a concentration of 20%-25% for reuse in production. Cooling is achieved through two-stage cooling using cooling water and chilled water. The liquid phase from ammonia stripping tower 7 recovers dilute ethanol with a concentration ≥95%. The liquid phase from ammonia stripping tower 7 then enters flash tank 9 and vaporization membrane 10 sequentially for dehydration and concentration to 99.5%. The dilute ethanol side of vaporization membrane 10 is connected to dilute ethanol tower 5, and the concentrated ethanol side of vaporization membrane 10 outputs concentrated ethanol.

[0035] The liquid phases from the bottom of the dilute alcohol tower 5 and the concentrated alcohol tower 6 both enter the wastewater equalization tank 11. The wastewater equalization tank is connected to a hydrochloric acid dosing system, which has the same structure as the ammonia dosing system, to add hydrochloric acid into the wastewater equalization tank 11 for mixing and homogenization. The wastewater equalization tank 11 is equipped with a multi-media filter 12, a bag filter 13, a first intermediate water tank 14, and a high-pressure reverse osmosis membrane concentration system 15 in sequence along the effluent direction. The backwash water from the multi-media filter 12 enters the wastewater equalization tank 11, and the backwash water from the first intermediate water tank 14 enters the multi-media filter 12. After being filtered by the multi-media filter 12 and the bag filter 13, the wastewater from the equalization tank 11 enters the first intermediate water tank 14 for temporary storage, and then enters the high-pressure reverse osmosis membrane concentration system 15. The bag filter has a filtration accuracy of less than or equal to 5 μm. The bag filter permeate does not require ultrafiltration and can be directly concentrated in the high-pressure reverse osmosis membrane concentration system 15. The high-pressure reverse osmosis membrane concentration system 15 can be configured in the form of "STRO+DTRO", "MTRO+DTRO", etc. Alternatively, the bag filter can be replaced with ultrafiltration, or a "SWRO+DTRO" combination mode can be used.

[0036] The concentrate side of the high-pressure reverse osmosis membrane concentration system 15 is connected to the inlet of the reverse osmosis concentrate tank 21, and the outlet of the reverse osmosis concentrate tank 21 is connected to the inlet of the evaporator crystallizer 22. The evaporator crystallizer 22 can be in the form of "MVR", "multi-effect", "single-effect" etc. The concentrate of the high-pressure reverse osmosis membrane concentration system 15 first enters the reverse osmosis concentrate tank 21 and then enters the evaporator crystallizer 22. The mother liquor produced by crystallization in the evaporator crystallizer 22 enters the discharge mother liquor tank 23 and the mother liquor dryer 24 in sequence. The impurities produced by the evaporator crystallizer and the mother liquor dryer are recovered.

[0037] The permeate side of the high-pressure reverse osmosis membrane concentration system 15 is connected to the inlet of the second intermediate water tank 16, and the outlet of the second intermediate water tank 16 is connected to the inlet of the low-pressure reverse osmosis membrane concentration system 17. The permeate from the high-pressure reverse osmosis membrane concentration system 15 first enters the second intermediate water tank 16 and then enters the low-pressure reverse osmosis membrane concentration system 17. The permeate is further filtered and removed by the low-pressure reverse osmosis membrane to achieve compliant permeate and reuse. The concentrate from the low-pressure reverse osmosis membrane concentration system 17 is returned to the first intermediate water tank 14. The permeate from the low-pressure reverse osmosis membrane concentration system 14, the evaporation crystallizer 22, and the condensate from the mother liquor dryer 24 enter the first permeate tank 18. The effluent from the first permeate tank 18 is indirectly discharged. Alternatively, the effluent from the first permeate tank 18 sequentially enters the A / O biological system 19 and the second permeate tank 20. The effluent from the second permeate tank 20 is directly discharged. The A / O biological system 19 is a combination of an A / O tank and a secondary sedimentation tank, or a combination of an A / O tank and an MBR membrane.

[0038] It should be noted that the pools involved in this utility model can all be in the form of tanks or water tanks. The connection between each treatment unit is made by conventional means such as pipelines. The transportation of sewage and other media between each treatment unit is carried out by means of pumping, gravity flow, etc. Ethanol and ammonia water are reused in the plant and sewage is discharged in compliance with standards.

[0039] like Figure 2 As shown, this utility model provides a method for treating wastewater from the production of nano-zirconia toughened ceramic powder, comprising:

[0040] Step 1: Collect the reaction liquid, water washing water and alcohol washing water generated in the nano-zirconia toughened ceramic powder production area separately; wherein, the reaction liquid and water washing water are low alcohol content wastewater (ethanol content less than 15%), which are collected in the first mixing tank; the alcohol washing water is high alcohol content wastewater (ethanol content greater than 75%), which are collected in the second mixing tank 4.

[0041] Step 2: The pH value of the low-alcohol wastewater in the first mixing tank 1 is adjusted with ammonia water to convert free zirconium ions into zirconium hydroxide. Then, the zirconium hydroxide powder is concentrated step by step using a columnar vibrating ultrafiltration membrane. After concentration, the high-purity powder is recovered by pressure filtration and finally returned to the production process. The permeate is temporarily stored in the vibrating membrane permeate tank 3, and the zirconium ion concentration in the permeate is less than 20 mg / L.

[0042] Step 3: After adding alkali to the waste liquid in the vibrating membrane product water tank 3, it is distilled in the dilute alcohol tower 5. The high alcohol content wash water is distilled in the mixing tank 4 after adding alkali.

[0043] Step 4: Dilute alcohol tower 5 and concentrated alcohol tower 6 are alcohol distillation towers. The ethanol content of the liquid phase product water is controlled to be below 50 mg / L and the ammonia nitrogen content to be below 40 mg / L. The liquid phase product water is discharged into the wastewater equalization tank 11. All the gas phase enters the same ammonia removal tower 7 for cooling and distillation. The liquid phase of the ammonia removal tower is used to recover ethanol, and the gas phase enters the ammonia absorption tower 8 to recover ammonia water with a concentration of 20%-25% for reuse in production. The cooling is achieved by two-stage cooling using cooling water and chilled water.

[0044] Step 5: The liquid phase of the deammoniation tower 7 can recover ethanol with a concentration of about 95%. The concentration of ethanol is increased to more than 99.5% by the "flash tank 9 + vaporization membrane 10", which can be directly reused in production. The dilute alcohol waste liquid produced by the vaporization membrane 10 contains an ethanol concentration of about 1.0% and is mixed into the dilute alcohol tower 5 for distillation treatment. Furthermore, the vaporization membrane is a zeolite membrane, and the membrane separation unit is composed of multiple membrane modules connected in series. The operating temperature is 118-135℃.

[0045] Step 6: The wastewater collected in the wastewater equalization tank 11 is treated by pH adjustment and homogenization, and then passed through a multi-media filter 12 and a bag filter 13. The filtration accuracy of the bag filter 13 is less than or equal to 5μm. The bag filter permeate is buffered in the first intermediate water tank 14. The backwash water for the multi-media filter comes from the first intermediate water tank 14, and the backwash wastewater enters the wastewater equalization tank 11.

[0046] Step 7: The bag filter water does not require ultrafiltration. After being buffered in the first intermediate water tank 14, it is directly promoted to the high-pressure reverse osmosis membrane concentration system 15 for concentration treatment. The combination of the high-pressure reverse osmosis membrane concentration system 15 is preferably "MTRO+DTRO", which can ensure the concentration ratio and reduce the project cost.

[0047] Step 8: The feed water TDS of the high-pressure reverse osmosis membrane concentration system 15 is about 35000 mg / L. The first stage STRO or MTRO permeate water rate is 40%-50%, the second stage DTRO permeate water rate is 40%-50%, and the total permeate water rate is 64%-70%. The concentrate produced by the high-pressure reverse osmosis membrane concentration system 15 flows into the reverse osmosis concentrate tank 21, and the permeate flows into the second intermediate water tank 16.

[0048] Step 9: The effluent from the second intermediate water tank 16 is treated by the low-pressure reverse osmosis membrane concentration system 17, which consists of two low-pressure reverse osmosis membranes. The permeate is mixed with the evaporation condensate produced by the evaporator crystallizer 22 and the mother liquor dryer 24 and flows into the first permeate tank 18, which can meet the indirect discharge standards in Table 1. The concentrate from the low-pressure reverse osmosis membrane concentration system 17 flows into the first intermediate water tank 14.

[0049] Step 10: Wastewater in reverse osmosis concentrate tank 21 is pumped into evaporator crystallizer 22, eventually producing mixed salts (mainly sodium chloride and sodium organic acid salts). The evaporated condensate flows into the first product water tank 18. Evaporator crystallizer 22 can be of the form of MVR, single-effect, multi-effect, etc., with MVR being preferred.

[0050] Step 11: The mother liquor discharged from the evaporator crystallizer 22 is collected in the mother liquor tank 23 and processed by the mother liquor dryer 24. The condensate from the mother liquor dryer 24 is also collected in the first production water tank 18. The mother liquor dryer 24 is preferably a drum type, made of carbon steel with chrome plating. The crystalline impurities produced are mainly sodium formate.

[0051] Step 12: The wastewater in the first production water tank 18 contains low concentrations of ethanol and ammonia nitrogen, with COD ≤ 200 mg / L, ammonia nitrogen ≤ 20 mg / L, and TDS ≤ 500 mg / L. After treatment by the A / O biological system 19, the low-concentration production water containing ethanol and ammonia nitrogen can meet the direct discharge standards in Table 1. The preferred biological treatment process is "A / O + secondary sedimentation". Before biological treatment, two-stage membrane separation has been performed, resulting in low organic matter and ammonia nitrogen load, low sludge production, and a high rate of compliance with biological treatment standards.

[0052] The advantages of this utility model are:

[0053] This invention fully considers the characteristics of wastewater from the production of nanopowder materials and has a thorough understanding of its components. While ensuring water quality meets standards, it maximizes resource recovery. The main process adopts either "alcohol extraction and ammonia removal + membrane concentration + evaporation crystallization" or "alcohol extraction and ammonia removal + membrane concentration + evaporation crystallization + biochemical treatment." The recovered zirconium hydroxide, ethanol, and ammonia can be directly reused in production, solving the problem of high salinity in wastewater and improving the water production guarantee rate. This invention reduces the organic matter and ammonia nitrogen load of the subsequent biochemical process through pre-membrane separation. The organic matter concentration after membrane separation is less than 200 mg / L, which can meet the indirect discharge standard. It eliminates the impact of high salinity on the biochemical system and ensures that the biochemical effluent consistently meets standards.

[0054] The above are merely preferred embodiments of this utility model and are not intended to limit the scope of this utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A treatment system for wastewater from the production of nano-zirconia toughened ceramic powder, the wastewater comprising reaction clarified liquid, washing water, and alcohol washing water, wherein the reaction clarified liquid and washing water are low-alcohol wastewater, and the alcohol washing water is high-alcohol wastewater; characterized in that, include: A first mixing tank for collecting low-alcohol-content wastewater and a second mixing tank for collecting high-alcohol-content wastewater; After ammonia neutralization and zirconium removal are completed in the first mixing tank, a vibrating membrane, a vibrating membrane product water tank, and a dilute alcohol tower are sequentially installed in the water outlet direction of the first mixing tank; after alkali mixing is completed in the second mixing tank, a concentrated alcohol tower is installed in the water outlet direction of the second mixing tank. The gas phases from both the dilute alcohol tower and the concentrated alcohol tower enter the ammonia removal tower. The gas phase from the ammonia removal tower enters the ammonia absorption tower. The liquid phase from the ammonia removal tower sequentially enters the flash tank and the vaporization membrane. The dilute alcohol side of the vaporization membrane is connected to the dilute alcohol tower. The liquid phases from both the dilute alcohol tower and the concentrated alcohol tower enter the wastewater equalization tank. The wastewater equalization tank is equipped with a filtration system and a high-pressure reverse osmosis membrane concentration system in sequence at the outlet direction. The concentrated water from the high-pressure reverse osmosis membrane concentration system enters the evaporator crystallizer, and the mother liquor from the evaporator crystallizer enters the mother liquor dryer. The permeate from the high-pressure reverse osmosis membrane concentration system enters the low-pressure reverse osmosis membrane concentration system, and the concentrated water from the low-pressure reverse osmosis membrane concentration system returns to the high-pressure reverse osmosis membrane concentration system. The permeate from the low-pressure reverse osmosis membrane concentration system, the evaporator crystallizer, and the condensate from the mother liquor dryer are discharged.

2. The wastewater treatment system for the production of nano-zirconia toughened ceramic powder as described in claim 1, characterized in that, The first mixing tank is connected to an ammonia dosing system, the vibrating membrane permeate tank and the second mixing tank are connected to a sodium hydroxide dosing system, and the wastewater equalization tank is connected to a hydrochloric acid dosing system; wherein, the ammonia dosing system, the sodium hydroxide dosing system and the hydrochloric acid dosing system all include dosing tanks, and the dosing tanks are connected to the dosing ports of the first mixing tank, the vibrating membrane permeate tank, the second mixing tank or the wastewater equalization tank through dosing pipelines.

3. The wastewater treatment system for the production of nano-zirconia toughened ceramic powder as described in claim 1, characterized in that, The liquid phase in the deammoniation tower is dilute ethanol. After the liquid phase in the deammoniation tower is dehydrated and concentrated by the flash tank and vaporization membrane, concentrated ethanol is output from the concentrated water meter of the vaporization membrane.

4. The wastewater treatment system for the production of nano-zirconia toughened ceramic powder as described in claim 1, characterized in that, The filtration system includes a multi-media filter, a bag filter, and a first intermediate water tank arranged sequentially along the wastewater treatment direction; wherein, the backwash water of the multi-media filter enters the wastewater equalization tank, the backwash water of the first intermediate water tank enters the multi-media filter, and the concentrate from the low-pressure reverse osmosis membrane concentration system returns to the first intermediate water tank.

5. The wastewater treatment system for the production of nano-zirconia toughened ceramic powder as described in claim 1, characterized in that, A second intermediate water tank is provided between the high-pressure reverse osmosis membrane concentration system and the low-pressure reverse osmosis membrane concentration system; a reverse osmosis concentrate tank is provided between the high-pressure reverse osmosis membrane concentration system and the evaporator crystallizer.

6. The wastewater treatment system for the production of nano-zirconia toughened ceramic powder as described in claim 1, characterized in that, The permeate from the low-pressure reverse osmosis membrane concentration system, the condensate from the evaporator crystallizer and the mother liquor dryer enter the first permeate tank, and the effluent from the first permeate tank is indirectly discharged; or, the effluent from the first permeate tank enters the A / O biochemical system and the second permeate tank in sequence, and the effluent from the second permeate tank is directly discharged.

7. The wastewater treatment system for the production of nano-zirconia toughened ceramic powder as described in any one of claims 1 to 6, characterized in that, The evaporator crystallizer is an MVR evaporator crystallizer, a multi-effect evaporator crystallizer, or a single-effect evaporator crystallizer; the high-pressure reverse osmosis membrane concentration system is a combination of STRO membrane and DTRO membrane, or a combination of MTRO membrane and DTRO membrane.

8. The wastewater treatment system for the production of nano-zirconia toughened ceramic powder as described in claim 6, characterized in that, The A / O biochemical system is a combination of an A / O tank and a secondary sedimentation tank, or a combination of an A / O tank and an MBR membrane.

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