CN111153537A - High-salinity wastewater treatment system and process for improving sodium chloride recycling rate - Google Patents
High-salinity wastewater treatment system and process for improving sodium chloride recycling rate Download PDFInfo
- Publication number
- CN111153537A CN111153537A CN201910261285.7A CN201910261285A CN111153537A CN 111153537 A CN111153537 A CN 111153537A CN 201910261285 A CN201910261285 A CN 201910261285A CN 111153537 A CN111153537 A CN 111153537A
- Authority
- CN
- China
- Prior art keywords
- sodium chloride
- water
- mother liquor
- evaporation
- sodium sulfate
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 title claims abstract description 417
- 239000011780 sodium chloride Substances 0.000 title claims abstract description 208
- 238000000034 method Methods 0.000 title claims abstract description 81
- 230000008569 process Effects 0.000 title claims abstract description 29
- 238000004065 wastewater treatment Methods 0.000 title claims abstract description 25
- 238000004064 recycling Methods 0.000 title claims abstract description 14
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 283
- 238000001728 nano-filtration Methods 0.000 claims abstract description 197
- 150000003839 salts Chemical class 0.000 claims abstract description 157
- PMZURENOXWZQFD-UHFFFAOYSA-L Sodium Sulfate Chemical compound [Na+].[Na+].[O-]S([O-])(=O)=O PMZURENOXWZQFD-UHFFFAOYSA-L 0.000 claims abstract description 152
- 229910052938 sodium sulfate Inorganic materials 0.000 claims abstract description 149
- 235000011152 sodium sulphate Nutrition 0.000 claims abstract description 149
- 239000012452 mother liquor Substances 0.000 claims abstract description 148
- 238000001223 reverse osmosis Methods 0.000 claims abstract description 104
- 238000002425 crystallisation Methods 0.000 claims abstract description 98
- 230000008025 crystallization Effects 0.000 claims abstract description 98
- 239000012528 membrane Substances 0.000 claims abstract description 90
- 238000002156 mixing Methods 0.000 claims abstract description 86
- 238000001914 filtration Methods 0.000 claims abstract description 71
- 229910052710 silicon Inorganic materials 0.000 claims abstract description 48
- 239000010703 silicon Substances 0.000 claims abstract description 48
- 238000000926 separation method Methods 0.000 claims abstract description 46
- 239000003814 drug Substances 0.000 claims abstract description 32
- 239000002351 wastewater Substances 0.000 claims abstract description 26
- 238000004519 manufacturing process Methods 0.000 claims abstract description 13
- DGAQECJNVWCQMB-PUAWFVPOSA-M Ilexoside XXIX Chemical compound C[C@@H]1CC[C@@]2(CC[C@@]3(C(=CC[C@H]4[C@]3(CC[C@@H]5[C@@]4(CC[C@@H](C5(C)C)OS(=O)(=O)[O-])C)C)[C@@H]2[C@]1(C)O)C)C(=O)O[C@H]6[C@@H]([C@H]([C@@H]([C@H](O6)CO)O)O)O.[Na+] DGAQECJNVWCQMB-PUAWFVPOSA-M 0.000 claims abstract description 7
- 229910052708 sodium Inorganic materials 0.000 claims abstract description 7
- 239000011734 sodium Substances 0.000 claims abstract description 7
- 238000001704 evaporation Methods 0.000 claims description 176
- 230000008020 evaporation Effects 0.000 claims description 175
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 claims description 47
- 239000013078 crystal Substances 0.000 claims description 46
- 239000000047 product Substances 0.000 claims description 29
- 238000001035 drying Methods 0.000 claims description 21
- 239000011259 mixed solution Substances 0.000 claims description 20
- 239000002562 thickening agent Substances 0.000 claims description 20
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 claims description 14
- 238000004806 packaging method and process Methods 0.000 claims description 11
- 238000012856 packing Methods 0.000 claims description 11
- QAOWNCQODCNURD-UHFFFAOYSA-L Sulfate Chemical compound [O-]S([O-])(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-L 0.000 claims description 10
- LSVVNVHHHMEPJZ-UHFFFAOYSA-L [Na+].[Na+].[O-]S(=O)(=O)SS([O-])(=O)=O Chemical compound [Na+].[Na+].[O-]S(=O)(=O)SS([O-])(=O)=O LSVVNVHHHMEPJZ-UHFFFAOYSA-L 0.000 claims description 10
- 239000002002 slurry Substances 0.000 claims description 10
- 150000002500 ions Chemical class 0.000 claims description 7
- 239000002244 precipitate Substances 0.000 claims description 7
- 230000009467 reduction Effects 0.000 claims description 6
- 238000007865 diluting Methods 0.000 claims description 5
- 230000001105 regulatory effect Effects 0.000 claims description 4
- 239000012141 concentrate Substances 0.000 claims description 3
- 230000008901 benefit Effects 0.000 abstract description 4
- 238000011084 recovery Methods 0.000 abstract description 3
- 239000010802 sludge Substances 0.000 abstract description 2
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 description 10
- 229920006395 saturated elastomer Polymers 0.000 description 3
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 2
- 239000003245 coal Substances 0.000 description 2
- 238000010790 dilution Methods 0.000 description 2
- 239000012895 dilution Substances 0.000 description 2
- 239000000243 solution Substances 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 229940079593 drug Drugs 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000000717 retained effect Effects 0.000 description 1
- XJKVPKYVPCWHFO-UHFFFAOYSA-N silicon;hydrate Chemical compound O.[Si] XJKVPKYVPCWHFO-UHFFFAOYSA-N 0.000 description 1
- 159000000000 sodium salts Chemical class 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F9/00—Multistage treatment of water, waste water or sewage
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01D—COMPOUNDS OF ALKALI METALS, i.e. LITHIUM, SODIUM, POTASSIUM, RUBIDIUM, CAESIUM, OR FRANCIUM
- C01D3/00—Halides of sodium, potassium or alkali metals in general
- C01D3/04—Chlorides
- C01D3/06—Preparation by working up brines; seawater or spent lyes
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F1/00—Treatment of water, waste water, or sewage
- C02F1/001—Processes for the treatment of water whereby the filtration technique is of importance
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F1/00—Treatment of water, waste water, or sewage
- C02F1/02—Treatment of water, waste water, or sewage by heating
- C02F1/04—Treatment of water, waste water, or sewage by heating by distillation or evaporation
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F1/00—Treatment of water, waste water, or sewage
- C02F1/44—Treatment of water, waste water, or sewage by dialysis, osmosis or reverse osmosis
- C02F1/441—Treatment of water, waste water, or sewage by dialysis, osmosis or reverse osmosis by reverse osmosis
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F1/00—Treatment of water, waste water, or sewage
- C02F1/44—Treatment of water, waste water, or sewage by dialysis, osmosis or reverse osmosis
- C02F1/442—Treatment of water, waste water, or sewage by dialysis, osmosis or reverse osmosis by nanofiltration
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F1/00—Treatment of water, waste water, or sewage
- C02F1/66—Treatment of water, waste water, or sewage by neutralisation; pH adjustment
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F2301/00—General aspects of water treatment
- C02F2301/08—Multistage treatments, e.g. repetition of the same process step under different conditions
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
- Y02A20/00—Water conservation; Efficient water supply; Efficient water use
- Y02A20/124—Water desalination
- Y02A20/131—Reverse-osmosis
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Engineering & Computer Science (AREA)
- Life Sciences & Earth Sciences (AREA)
- Hydrology & Water Resources (AREA)
- Environmental & Geological Engineering (AREA)
- Water Supply & Treatment (AREA)
- Materials Engineering (AREA)
- Inorganic Chemistry (AREA)
- Separation Using Semi-Permeable Membranes (AREA)
- Heat Treatment Of Water, Waste Water Or Sewage (AREA)
Abstract
The invention discloses a high-salinity wastewater treatment system for improving the resource rate of sodium chloride, which comprises an adjusting tank, a primary nanofiltration membrane device, a sodium sulfate evaporative crystallization unit, an RO membrane device, an RO concentrated water tank, a sodium chloride evaporative crystallization unit, a secondary nanofiltration membrane device, a mother liquor mixing tank, a dosing tank, a filtering device and a miscellaneous salt evaporative crystallization unit, wherein the adjusting tank is connected with the primary nanofiltration membrane device; the water resource is saved, the environment is protected, the recovery of salt in the high-salinity wastewater is realized, and the economic benefit of enterprises is improved. The invention also discloses a high-salinity wastewater treatment process for improving the sodium chloride recycling rate, which comprises the following working procedures: the process comprises the steps of one-stage nanofiltration salt separation; reverse osmosis filtration in the second procedure; step (3) sodium trithione crystallization and sodium chloride crystallization; step four, mixing and adding medicine; step five, filtering and removing silicon; the sixth step of secondary nanofiltration salt separation; step seven, crystallizing miscellaneous salt; the recycling rate of sodium chloride is improved, and the problems of large sludge production, large medicament addition and medicament cost caused by the traditional method are solved.
Description
The technical field is as follows:
the invention relates to the field of wastewater treatment, in particular to a high-salinity wastewater treatment system and a high-salinity wastewater treatment process for improving the recycling rate of sodium chloride.
Background art:
coal chemical industry enterprises can produce a large amount of high salt waste water in the production operation, and the high salt waste water has characteristics such as complicated composition, quality of water and quantity fluctuation are big, salinity content height, because at present china's coal chemical industry enterprises mostly concentrate on the fragile western region of ecological environment, do not have the dirty water body of receiving in the periphery, do not possess the waste water and arrange the condition outward, and direct arranging such high salt waste water outward can also cause the waste of sodium salt resource, consequently must handle the back and just can externally discharge.
At present, the high-salt wastewater is treated by adopting a nanofiltration salt separation mode, chloride ions and sulfate ions in the high-salt wastewater are separated by nanofiltration, and sodium chloride crystal salt and sodium sulfate crystal salt can be obtained by respectively carrying out evaporative crystallization treatment on nanofiltration produced water and nanofiltration concentrated water. However, because the content of chloride ions and sulfate ions in the high-salt wastewater is high, a certain amount of chloride ions and a certain amount of sulfate ions are contained in nanofiltration concentrated water obtained after nanofiltration treatment, and a certain amount of sulfate radicals are also contained in nanofiltration produced water, so that the purity of finally obtained sodium chloride crystal salt and sodium sulfate crystal salt is not high, the sodium chloride crystal salt and the sodium sulfate crystal salt are difficult to reach the standard of selling, and the chloride ions cannot be fully recovered, so that the resource rate of sodium chloride is low, and the economic production of enterprises is not facilitated.
The invention content is as follows:
the first purpose of the invention is to provide a high-salinity wastewater treatment system which is safe, reliable, stable in operation and capable of improving the sodium chloride recycling rate;
the second purpose of the invention is to provide a high-salinity wastewater treatment process which has low treatment cost and can effectively recover chloride ions and improve the recycling rate of sodium chloride.
The first purpose of the invention is implemented by the following technical scheme:
the high-salinity wastewater treatment system for improving the resource rate of sodium chloride comprises an adjusting tank, a primary nanofiltration membrane device, a sodium sulfate evaporative crystallization unit, an RO membrane device, an RO concentrated water tank, a sodium chloride evaporative crystallization unit, a secondary nanofiltration membrane device, a mother liquor mixing tank, a dosing tank, a filtering device and a miscellaneous salt evaporative crystallization unit;
the water outlet of the regulating tank is communicated with the water inlet of the primary nanofiltration membrane device, and the concentrated water outlet of the primary nanofiltration membrane device is communicated with the water inlet of the sodium sulfate evaporation raw water tank of the sodium sulfate evaporation crystallization unit;
the water outlet of the first-stage nanofiltration membrane device is communicated with the water inlet of the RO membrane device, the concentrated water outlet of the RO membrane device is communicated with the water inlet of the RO concentrated water tank, and the water outlet of the RO concentrated water tank is communicated with the water inlet of the sodium chloride evaporation raw water tank of the sodium chloride evaporation crystallization unit;
a mother liquor outlet of a sodium sulfate evaporative crystallizer of the sodium sulfate evaporative crystallization unit and a mother liquor outlet of a sodium chloride evaporative crystallizer of the sodium chloride evaporative crystallization unit are both communicated with a water inlet of the mother liquor mixing tank, a water outlet of the mother liquor mixing tank is communicated with a water inlet of the filtering device, a water outlet of the filtering device is communicated with a water inlet of the secondary nanofiltration membrane device, a water production outlet of the secondary nanofiltration membrane device is communicated with a water inlet of the RO concentrated water tank, and a concentrated water outlet of the secondary nanofiltration membrane device is communicated with a water inlet of an evaporative mother liquor mixing tank of the miscellaneous salt evaporative crystallization unit;
the water outlet of the RO membrane device is divided into two paths to be respectively communicated with the mother liquor mixing tank and the water inlet of the secondary nanofiltration membrane device;
and the medicine outlet of the medicine adding tank is communicated with the water inlet of the mother liquor mixing tank.
Further, the sodium sulfate evaporation crystallization unit comprises a sodium sulfate evaporation raw water pool, a sodium sulfate evaporation crystallizer, a sodium sulfate thickener, a sodium sulfate centrifuge, a sodium sulfate drying bed and a sodium sulfate packaging machine;
the water outlet of the sodium sulfate evaporation raw water tank is communicated with the inlet of the sodium sulfate evaporation crystallizer, the crystal slurry outlet of the sodium sulfate evaporation crystallizer is communicated with the inlet of the sodium sulfate thickener, the crystal slurry outlet of the sodium sulfate thickener is communicated with the inlet of the sodium sulfate centrifugal machine, the crystallized salt outlet of the sodium sulfate centrifugal machine is communicated with the inlet of the sodium sulfate drying bed, and the outlet of the sodium sulfate drying bed is communicated with the inlet of the sodium sulfate packing machine.
Further, the sodium chloride evaporation crystallization unit comprises a sodium chloride evaporation raw water pool, a sodium chloride evaporation crystallizer, a sodium chloride thickener, a sodium chloride centrifugal machine, a sodium chloride drying bed and a sodium chloride packing machine;
the water outlet of the sodium chloride evaporation raw water tank is communicated with the water inlet of the sodium chloride evaporation crystallizer, the crystal slurry port of the sodium chloride evaporation crystallizer is communicated with the inlet of the sodium chloride thickener, the crystal slurry outlet of the sodium chloride thickener is communicated with the inlet of the sodium chloride centrifugal machine, the crystal salt outlet of the sodium chloride centrifugal machine is communicated with the inlet of the sodium chloride drying bed, and the outlet of the sodium chloride drying bed is communicated with the inlet of the sodium chloride packing machine.
Further, the mixed salt evaporation crystallization unit comprises an evaporation mother liquor mixing tank, a mixed salt evaporation crystallizer, a mixed salt centrifuge, a mixed salt dryer and a mixed salt packaging machine;
the water outlet of the evaporation mother liquor mixing tank is communicated with the water inlet of the miscellaneous salt evaporation crystallizer, the mother liquor outlet of the miscellaneous salt evaporation crystallizer is communicated with the inlet of the miscellaneous salt centrifuge, the crystallized salt outlet of the miscellaneous salt centrifuge is communicated with the inlet of the miscellaneous salt dryer, and the outlet of the miscellaneous salt dryer is communicated with the inlet of the miscellaneous salt packaging machine.
The second purpose of the invention is implemented by the following technical scheme:
the high-salinity wastewater treatment process for improving the resource utilization rate of sodium chloride comprises the following working procedures: the process comprises the steps of one-stage nanofiltration salt separation; reverse osmosis filtration in the second procedure; step (3) sodium trithione crystallization and sodium chloride crystallization; step four, mixing and adding medicine; step five, filtering and removing silicon; the sixth step of secondary nanofiltration salt separation; step seven, crystallizing miscellaneous salt; wherein:
the process comprises the following steps of one-stage nanofiltration salt separation: adjusting the pH value in the adjusting tank to 6-9, wherein TDS is more than or equal to 40000mg/L, c (SO)4 2-)≥5000mg/L，c(SO4 2-):c(Cl-) Sending the high-salinity wastewater with the concentration of less than or equal to 1, the concentration of c (Si) less than or equal to 20mg/L and the concentration of COD less than or equal to 450mg/L into a first-stage nanofiltration membrane device of a high-salinity wastewater treatment system for improving the resource rate of sodium chloride, and carrying out first-stage nanofiltration salt separation treatment to obtain first-stage nanofiltration product water and first-stage nanofiltration concentrated water SO as to enrich sulfate ions in the first-stage nanofiltration concentrated water and concentrate c (SO) in the first-stage nanofiltration concentrated water4 2-) 80000-100000 mg/L;
reverse osmosis filtration in the second procedure: sending the primary nanofiltration product water obtained in the primary nanofiltration salt separation in the first step into an RO membrane device for reverse osmosis filtration treatment, further concentrating ions in the primary nanofiltration product water to obtain RO concentrated water and RO product water, wherein the TDS in the RO concentrated water is more than 50000 mg/L;
the procedure comprises the following steps of sodium trithionate crystallization and sodium chloride crystallization: sending the first-stage nanofiltration concentrated water obtained in the first-stage nanofiltration salt separation of the procedure into a sodium sulfate evaporation crystallizer for evaporation crystallization to obtain sodium sulfate crystallized salt and sodium sulfate evaporation mother liquor, wherein c (SO) in the sodium sulfate evaporation mother liquor4 2-)＝48000mg/L，c(Cl-) 160000-180000 mg/L;
feeding the RO concentrated water obtained in the reverse osmosis filtration in the second procedure into a sodium chloride evaporation crystallizer for evaporation crystallization to obtain sodium chloride crystal salt and sodium chloride evaporation mother liquor c (Cl)-) 180000mg/L, sodium chloride evaporated c (SO) in mother liquor4 2-)≤48000mg/L；
The fourth step is mixing and adding medicine: feeding sodium sulfate evaporation mother liquor and sodium chloride evaporation mother liquor obtained in the sodium sulfate crystal and sodium chloride crystal in the working procedure and RO product water obtained in reverse osmosis filtration in the working procedure II into a mother liquor mixing tank for mixing and homogenizing, wherein the RO product water amount entering the mother liquor mixing tank is 1-3 times of the total amount of the sodium sulfate evaporation mother liquor and the sodium chloride evaporation mother liquor entering the mother liquor mixing tank, and diluting the sodium sulfate evaporation mother liquor and the sodium chloride evaporation mother liquor to prevent the sodium sulfate evaporation mother liquor and the sodium chloride evaporation mother liquor from being separated out due to the temperature reduction of the sodium sulfate evaporation mother liquor and the sodium chloride evaporation mother liquor after entering the mother liquor mixing tank; adding hydrochloric acid into the mother liquor mixing tank through a medicine adding tank to obtain a mixed solution with the pH of 8-8.5 so as to reduce the solubility of silicon in the mixed solution;
and the fifth step is to filter and remove silicon: sending the mixed solution obtained in the mixing and adding of the step four into a filtering device for filtering treatment, removing silicon precipitates separated out from the mixed solution to obtain silicon-removed water, wherein c (Si) in the silicon-removed water is less than or equal to 150 mg/L;
the six-stage nanofiltration salt separation of the working procedure: feeding RO produced water obtained in the reverse osmosis filtration in the second procedure and silicon-removed water obtained in the silicon removal filtration in the fifth procedure into a secondary nanofiltration membrane device, and performing secondary nanofiltration salt separation treatment to obtain secondary nanofiltration produced water and secondary nanofiltration concentrated water; the concentration of silicon is diluted by RO produced water, so that c (Si) in the water entering the secondary nanofiltration membrane device is less than or equal to 75mg/L, and the water inlet requirement of the secondary nanofiltration membrane device is met; c (SO) in concentrated water of secondary nanofiltration4 2-) 80000-100000 mg/L of the secondary nanofiltration water production is returned to the sodium trithionate crystal and the sodium chloride crystal in the working procedure for sodium chloride crystallization treatment;
the process comprises the following steps: and (3) feeding the secondary nanofiltration concentrated water obtained in the secondary nanofiltration salt separation in the sixth procedure into a mixed salt evaporation crystallizer for evaporation crystallization to obtain mixed salt.
The invention has the advantages that:
the system saves water resources, protects the environment, has stable operation, safety, reliability and lower operation cost, avoids the damage of high-salinity wastewater to the environment caused by external emission, and has great social benefit; the recycling of salt in the high-salinity wastewater is realized, the recycling rate of sodium chloride is improved, the obtained sodium chloride crystal salt and sodium sulfate crystal salt have higher purity, can reach the standard of selling, and the economic benefit of enterprises is improved.
According to the process, divalent ions in the high-salinity wastewater are intercepted through a primary nanofiltration membrane device, and the obtained primary nanofiltration concentrated water is evaporated and crystallized to obtain anhydrous sodium sulfate; concentrating chloride ions in the obtained first-stage nanofiltration water through an RO membrane device, and evaporating and crystallizing the obtained RO concentrated water to obtain sodium chloride crystal salt; the sodium sulfate evaporation mother liquor and the sodium chloride evaporation mother liquor enter a mother liquor mixing tank to be mixed and homogenized, and RO (reverse osmosis) production water is added into the mother liquor mixing tank to dilute the sodium chloride and the sodium sulfate, so that the crystallized salt is ensured not to be separated out; then adding a medicament into the mother liquor mixing tank through a medicament adding tank to adjust the pH value, so that the solubility of silicon in the wastewater in the mother liquor mixing tank is reduced to the minimum, and then filtering the precipitated silicon precipitate through a filtering device; then, nanofiltration treatment is carried out through a secondary nanofiltration membrane device, chloride ions are further separated, and the obtained secondary nanofiltration produced water is returned to a sodium chloride evaporation crystallization unit, so that the sodium chloride is fully recovered, and the resource utilization rate of the sodium chloride is improved; most of COD and sulfate ions are intercepted on the side of the secondary nanofiltration concentrated water, and finally enter a mixed salt evaporation crystallization unit to obtain mixed salt after evaporation crystallization.
According to the process, the sodium sulfate evaporation mother liquor and the sodium chloride evaporation mother liquor are further subjected to salt separation through a secondary nanofiltration salt separation process, so that further recovery of chloride ions is realized, and the resource rate of sodium chloride is improved; the pH value of the wastewater is adjusted by adding hydrochloric acid, the solubility of total silicon in the wastewater is reduced to the maximum extent, and the precipitated silicon is removed by core-type filtration, so that the problems of large sludge generation amount, large medicament addition amount and medicament cost caused in the process of removing silicon by adding sodium metaaluminate are avoided; dilute mixing the mother liquor in introducing the mother liquor mixing tank through producing water with RO, ensure that sodium chloride and sodium sulfate can not appear, produce water through producing RO and cause the second grade to receive the filter membrane device and dilute except that the silicon water, with the concentration of silicon concentration and each ion in the reduction aquatic, not only realized producing the effective utilization of water to RO, the restriction has been made to the retrieval and utilization volume of water is produced to RO simultaneously, avoided dilution multiple too high to make sodium chloride evaporation crystallization unit inflow too big and the higher problem of investment cost and working costs that causes.
Description of the drawings:
in order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.
FIG. 1 is a schematic view of the system configuration of embodiment 1;
in the figure: an adjusting tank 1, a primary nanofiltration membrane device 2, a sodium sulfate evaporation crystallization unit 3, a sodium sulfate evaporation raw water tank 3-1, a sodium sulfate evaporation crystallizer 3-2, a sodium sulfate thickener 3-3, a sodium sulfate centrifuge 3-4, a sodium sulfate drying bed 3-5, a sodium sulfate packaging machine 3-6, an RO membrane device 4, a sodium chloride evaporation crystallization unit 5, a sodium chloride evaporation raw water tank 5-1, a sodium chloride evaporation crystallizer 5-2, a sodium chloride thickener 5-3, a sodium chloride centrifuge 5-4, a sodium chloride drying bed 5-5, a sodium chloride packaging machine 5-6, a secondary nanofiltration membrane device 6, a filtering device 7, a miscellaneous salt evaporation crystallization unit 8, an evaporation mother liquor mixing tank 8-1, a miscellaneous salt evaporation crystallizer 8-2, a miscellaneous salt centrifuge 8-3, a miscellaneous salt dryer 8-4, 8-5 parts of a miscellaneous salt packaging machine, 9 parts of an RO concentrated water tank, 10 parts of a mother liquor mixing tank and 11 parts of a medicine adding tank.
The specific implementation mode is as follows:
the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Example 1:
the high-salinity wastewater treatment system for improving the resource utilization rate of sodium chloride shown in fig. 1 comprises an adjusting tank 1, a primary nanofiltration membrane device 2, a sodium sulfate evaporative crystallization unit 3, an RO membrane device 4, an RO concentrated water tank 9, a sodium chloride evaporative crystallization unit 5, a secondary nanofiltration membrane device 6, a mother liquor mixing tank 10, a drug adding tank 11, a filtering device 7 and a miscellaneous salt evaporative crystallization unit 8;
the water outlet of the regulating tank 1 is communicated with the water inlet of the primary nanofiltration membrane device 2, and the concentrated water outlet of the primary nanofiltration membrane device 2 is communicated with the water inlet of a sodium sulfate evaporation raw water tank 3-1 of a sodium sulfate evaporation crystallization unit 3;
a water outlet of the primary nanofiltration membrane device 2 is communicated with a water inlet of an RO membrane device 4, a concentrated water outlet of the RO membrane device 4 is communicated with a water inlet of an RO concentrated water tank 9, and a water outlet of the RO concentrated water tank 9 is communicated with a water inlet of a sodium chloride evaporation raw water tank 5-1 of a sodium chloride evaporation crystallization unit 5;
a mother liquor outlet of a sodium sulfate evaporative crystallizer 3-2 of a sodium sulfate evaporative crystallization unit 3 and a mother liquor outlet of a sodium chloride evaporative crystallizer 5-2 of a sodium chloride evaporative crystallization unit 5 are both communicated with a water inlet of a mother liquor mixing tank 10, a water outlet of the mother liquor mixing tank 10 is communicated with a water inlet of a filtering device 7, a water outlet of the filtering device 7 is communicated with a water inlet of a secondary nanofiltration membrane device 6, a water production outlet of the secondary nanofiltration membrane device 6 is communicated with a water inlet of an RO concentrated water tank 9, and a concentrated water outlet of the secondary nanofiltration membrane device 6 is communicated with a water inlet of an evaporative mother liquor mixing tank 8-1 of a miscellaneous salt evaporative crystallization unit 8;
the water outlet of the RO membrane device 4 is respectively communicated with the mother liquor mixing tank 10 and the water inlet of the secondary nanofiltration membrane device 6 in two ways;
the medicine outlet of the medicine adding tank 11 is communicated with the water inlet of the mother liquor mixing pool 10.
The sodium sulfate evaporation crystallization unit 3 comprises a sodium sulfate evaporation raw water pool 3-1, a sodium sulfate evaporation crystallizer 3-2, a sodium sulfate thickener 3-3, a sodium sulfate centrifuge 3-4, a sodium sulfate drying bed 3-5 and a sodium sulfate packing machine 3-6;
the water outlet of the sodium sulfate evaporation raw water tank 3-1 is communicated with the inlet of a sodium sulfate evaporation crystallizer 3-2, the magma outlet of the sodium sulfate evaporation crystallizer 3-2 is communicated with the inlet of a sodium sulfate thickener 3-3, the magma outlet of the sodium sulfate thickener 3-3 is communicated with the inlet of a sodium sulfate centrifuge 3-4, the crystallized salt outlet of the sodium sulfate centrifuge 3-4 is communicated with the inlet of a sodium sulfate drying bed 3-5, and the outlet of the sodium sulfate drying bed 3-5 is communicated with the inlet of a sodium sulfate packing machine 3-6.
The sodium chloride evaporation crystallization unit 5 comprises a sodium chloride evaporation raw water pool 5-1, a sodium chloride evaporation crystallizer 5-2, a sodium chloride thickener 5-3, a sodium chloride centrifuge 5-4, a sodium chloride drying bed 5-5 and a sodium chloride packing machine 5-6;
the water outlet of the sodium chloride evaporation raw water tank 5-1 is communicated with the water inlet of a sodium chloride evaporation crystallizer 5-2, the crystal slurry port of the sodium chloride evaporation crystallizer 5-2 is communicated with the inlet of a sodium chloride thickener 5-3, the crystal slurry outlet of the sodium chloride thickener 5-3 is communicated with the inlet of a sodium chloride centrifugal machine 5-4, the crystal salt outlet of the sodium chloride centrifugal machine 5-4 is communicated with the inlet of a sodium chloride drying bed 5-5, and the outlet of the sodium chloride drying bed 5-5 is communicated with the inlet of a sodium chloride packing machine 5-6.
The mixed salt evaporation crystallization unit 8 comprises an evaporation mother liquor mixing tank 8-1, a mixed salt evaporation crystallizer 8-2, a mixed salt centrifuge 8-3, a mixed salt dryer 8-4 and a mixed salt packaging machine 8-5;
the water outlet of the evaporation mother liquor mixing tank 8-1 is communicated with the water inlet of the miscellaneous salt evaporation crystallizer 8-2, the mother liquor outlet of the miscellaneous salt evaporation crystallizer 8-2 is communicated with the inlet of the miscellaneous salt centrifuge 8-3, the crystallized salt outlet of the miscellaneous salt centrifuge 8-3 is communicated with the inlet of the miscellaneous salt dryer 8-4, and the outlet of the miscellaneous salt dryer 8-4 is communicated with the inlet of the miscellaneous salt packaging machine 8-5.
In the embodiment, the sodium sulfate evaporative crystallizer 3-2, the sodium chloride evaporative crystallizer 5-2 and the miscellaneous salt evaporative crystallizer 8-2 can adopt OSLO type evaporators; the filter device 7 is a pleated filter.
After the high-salinity wastewater in the regulating tank 1 is subjected to salt separation by the primary nanofiltration membrane device 2, sodium sulfate is mainly retained on the concentrated water side of primary nanofiltration, sodium chloride is mainly concentrated on the water production side of the primary nanofiltration, and meanwhile, the concentrated water side of the primary nanofiltration still contains sodium chloride and the water production side of the primary nanofiltration also contains sodium sulfate; and (3) passing the concentrated water subjected to primary nanofiltration through a sodium sulfate evaporation crystallization unit 3, separating anhydrous sodium sulfate, drying and packaging, and selling. In the process of sodium sulfate evaporation crystallization, the discharge amount of sodium sulfate evaporation mother liquor is controlled to ensure that the concentration of sodium chloride in the sodium sulfate evaporation mother liquor is lower than 180000mg/L and ensure that the sodium sulfate evaporation mother liquorSodium chloride in the product cannot be saturated and separated out; meanwhile, the amount of steam introduced into the sodium sulfate evaporation crystallizer 3-2 is controlled, COD is controlled to be lower than 20000mg/L, the concentration of silicon is controlled to be lower than 5000mg/L, silicon and COD are ensured not to be separated out, and the quality of the finally obtained anhydrous sodium sulfate reaches the qualified product standard of class II salt in the standard GB/T6009-2014. The discharged sodium sulfate evaporation mother liquor enters a mother liquor mixing tank 10, and the discharged sodium sulfate evaporates the mother liquor c (SO)4 2-) 48000mg/L, sodium sulfate concentration in saturated state, c (Cl)-) Below 180000mg/L, the concentration of sodium chloride is close to saturation.
The concentration of the first-stage nanofiltration produced water is further improved by the RO membrane device 4, so that the TDS is>50000mg/L to reduce the water inflow of the sodium chloride evaporative crystallization unit 5; the RO concentrated water concentrated by the RO membrane device 4 enters a sodium chloride evaporation crystallization unit 5, sodium chloride is separated and crystallized, and the sodium chloride is dried, packaged and sold. In the process of sodium chloride evaporation crystallization, the discharge amount of sodium chloride evaporation mother liquor is controlled, so that the concentration of sodium sulfate in the sodium chloride evaporation mother liquor is lower than 48000mg/L, and the sodium sulfate in the sodium chloride evaporation mother liquor is ensured not to be saturated and separated out; meanwhile, the amount of steam introduced into the sodium chloride evaporative crystallizer 5-2 is controlled to control COD to be lower than 20000mg/L and the concentration of silicon to be lower than 5000mg/L, so that silicon and COD are not separated out, and the quality of the finally obtained sodium chloride crystal salt reaches the secondary standard of refined industrial dry salt in GB/T5462-2015 Industrial salt standard. The discharged sodium chloride evaporation mother liquor enters a mother liquor mixing tank 10, and the discharged sodium chloride evaporation mother liquor is c (Cl)-) 180000mg/L, saturated sodium chloride concentration, c (SO)4 2-) 48000mg/L or less, and the concentration of sodium sulfate is close to saturation state.
In the embodiment, RO produced water with the water quantity equal to that in the mother liquor mixing tank 10 is added into the mother liquor mixing tank 10 to dilute the sodium chloride and the sodium sulfate, so that the crystallized salt is ensured not to be separated out. Then adding a medicament (hydrochloric acid or sulfuric acid) into the mother liquor mixing tank 10 through a medicament adding tank 11 to control the pH value of the wastewater in the mother liquor mixing tank 10 to be 8-8.5, further minimizing the solubility of silicon in the wastewater in the mother liquor mixing tank 10 to reduce the silicon concentration in the water to be below 150mg/L, then filtering the precipitated silicon precipitate through a filtering device 7, then entering a secondary nanofiltration membrane device 6, simultaneously adding RO produced water with the same water amount as that in the secondary nanofiltration membrane device 6 into the secondary nanofiltration membrane device 6 to dilute sodium chloride and sodium sulfate so as to reduce the silicon concentration in the water to be below 75mg/L, performing nanofiltration salt separation treatment through the secondary nanofiltration membrane device 6 after dilution so that chloride ions pass through a nanofiltration membrane, namely the nanofiltration membrane is enriched at the secondary nanofiltration water production side, and returning to a sodium chloride evaporative crystallization unit 5 to realize the full recovery of sodium chloride, thereby improving the resource utilization rate of the sodium chloride; most of COD and sulfate ions are intercepted on the side of the secondary nanofiltration concentrated water and finally enter a mixed salt evaporation crystallization unit 8 to obtain mixed salt after evaporation and crystallization.
Example 2:
the process for treating high-salinity wastewater by using the high-salinity wastewater treatment system for improving the sodium chloride recycling rate in embodiment 1 comprises the following steps of: the process comprises the steps of one-stage nanofiltration salt separation; reverse osmosis filtration in the second procedure; step (3) sodium trithione crystallization and sodium chloride crystallization; step four, mixing and adding medicine; step five, filtering and removing silicon; the sixth step of secondary nanofiltration salt separation; step seven, crystallizing miscellaneous salt; wherein:
the process comprises the following steps of (1) one-stage nanofiltration salt separation: adjusting the pH value of the adjusting tank 1 to 6, TDS to 47000mg/L, c (SO)4 2-) Is 5000mg/L, c (SO)4 2-):c(Cl-) Sending the high-salinity wastewater with the concentration of 0.7 and the concentration of c (Si) of 10mg/L, COD of 300mg/L into a first-stage nanofiltration membrane device 2 of a high-salinity wastewater treatment system for improving the resource rate of sodium chloride, carrying out first-stage nanofiltration treatment to obtain first-stage nanofiltration product water and first-stage nanofiltration concentrated water, SO that sulfate ions are enriched in the first-stage nanofiltration concentrated water, and c (SO) in the first-stage nanofiltration concentrated water4 2-) 86000mg/L, and c (Cl) in the first-stage nanofiltration produced water-) 15000 mg/L;
and (2) reverse osmosis filtration: one obtained in the one-stage nanofiltration salt separation of the working proceduresThe water produced by the first-stage nanofiltration is sent into an RO membrane device 4 for reverse osmosis filtration treatment, so that ions in the water produced by the first-stage nanofiltration are further concentrated to obtain RO concentrated water and RO produced water, wherein the TDS in the RO concentrated water is 55000mg/L, and c (Cl) in the RO concentrated water-) 25000 mg/L;
step (2), sodium trithionate crystallization and sodium chloride crystallization: feeding the first-stage nanofiltration concentrated water obtained in the step of one-stage nanofiltration salt separation into a sodium sulfate evaporative crystallizer 3-2 for evaporative crystallization to obtain sodium sulfate crystalline salt and sodium sulfate evaporation mother liquor, wherein c (SO) in the sodium sulfate evaporation mother liquor4 2-) 48000mg/L, c (Cl)-) 175000 mg/L;
feeding the RO concentrated water obtained in the reverse osmosis filtration in the second procedure into a sodium chloride evaporation crystallizer 5-2 for evaporation crystallization to obtain sodium chloride crystal salt and sodium chloride evaporation mother liquor, wherein c (Cl) in the sodium chloride evaporation mother liquor-) 180000mg/L, c (SO)4 2-) 47000 mg/L;
and step four, mixing and adding medicine: feeding sodium sulfate evaporation mother liquor and sodium chloride evaporation mother liquor obtained in the sodium sulfate crystal and sodium chloride crystal in the working procedure and RO product water obtained in reverse osmosis filtration in the working procedure II into a mother liquor mixing tank 10 for mixing and homogenizing, wherein the RO product water amount entering the mother liquor mixing tank 10 is equal to the sodium sulfate evaporation mother liquor and the sodium chloride evaporation mother liquor entering the mother liquor mixing tank 10, and the sodium sulfate evaporation mother liquor and the sodium chloride evaporation mother liquor are diluted to prevent the sodium sulfate and the sodium chloride from being separated out due to the temperature reduction of the sodium sulfate evaporation mother liquor and the sodium chloride evaporation mother liquor after entering the mother liquor mixing tank 10; adding hydrochloric acid into the mother liquor mixing tank 10 from a medicine adding tank 11 to obtain a mixed solution with the pH maintained at 8.1 so as to reduce the solubility of silicon in the mixed solution;
and a fifth step of filtering and removing silicon: sending the mixed solution obtained in the mixing and adding of the step four into a filtering device 7, filtering, removing silicon precipitates separated out from the mixed solution, and obtaining silicon-removed water, wherein c (Si) in the silicon-removed water is 120 mg/L;
and (3) carrying out secondary nanofiltration salt separation: the RO produced water obtained in the reverse osmosis filtration in the second procedure and the silicon-removed water obtained in the silicon removal filtration in the fifth procedure are sent into a secondary nanofiltration membrane device 6 for secondary nanofiltration treatment to obtain secondary nanoFiltering the produced water and the secondary nanofiltration concentrated water; the RO water yield entering the secondary nanofiltration membrane device 6 is equal to the silicon removal water yield entering the secondary nanofiltration membrane device 6, and the RO water yield is used for diluting the silicon concentration, so that the c (Si) in the water entering the secondary nanofiltration membrane device 6 is 60mg/L, and the water inlet requirement of the secondary nanofiltration membrane device 6 is met; c (SO) in concentrated water of secondary nanofiltration4 2-) 90000mg/L, returning the secondary nanofiltration water production to sodium trithionate crystallization and sodium chloride crystallization in the working procedure, and performing sodium chloride crystallization treatment;
step seven miscellaneous salt crystallization: and (3) feeding the secondary nanofiltration concentrated water obtained in the sixth secondary nanofiltration into a mixed salt evaporative crystallizer 8-2 for evaporative crystallization to obtain mixed salt.
Example 3:
the process for treating high-salinity wastewater by using the high-salinity wastewater treatment system for improving the sodium chloride recycling rate in embodiment 1 comprises the following steps of: the process comprises the steps of one-stage nanofiltration salt separation; reverse osmosis filtration in the second procedure; step (3) sodium trithione crystallization and sodium chloride crystallization; step four, mixing and adding medicine; step five, filtering and removing silicon; the sixth step of secondary nanofiltration salt separation; step seven, crystallizing miscellaneous salt; wherein:
the process comprises the following steps of (1) one-stage nanofiltration salt separation: adjusting the pH value of the adjusting tank 1 to 7, the TDS to 45000mg/L, c (SO)4 2-) Is 5500mg/L, c (SO)4 2-):c(Cl-) High-salinity wastewater with the concentration of 0.8 and the concentration of c (Si) of 15mg/L, COD mg/L to 250mg/L is sent into a first-stage nanofiltration membrane device 2 of a high-salinity wastewater treatment system for improving the resource rate of sodium chloride, and first-stage nanofiltration treatment is carried out to obtain first-stage nanofiltration product water and first-stage nanofiltration concentrated water, SO that sulfate ions are enriched in the first-stage nanofiltration concentrated water, and c (SO) in the first-stage nanofiltration concentrated water4 2-) 96000mg/L, and the water c (Cl) is produced by the first-stage nanofiltration-) 13000 mg/L;
and (2) reverse osmosis filtration: the first-stage nanofiltration product water obtained in the first-stage nanofiltration salt separation of the working procedures is sent to an RO membrane device 4 for reverse osmosis filtration treatment, ions in the first-stage nanofiltration product water are further concentrated to obtain RO concentrated water and RO product water, the TDS in the RO concentrated water is 54000mg/L, and c (Cl) in the RO concentrated water-) 21000 mg/L;
process for crystallization of sodium trithionate and sodium chloride: feeding the first-stage nanofiltration concentrated water obtained in the step of one-stage nanofiltration salt separation into a sodium sulfate evaporative crystallizer 3-2 for evaporative crystallization to obtain sodium sulfate crystalline salt and sodium sulfate evaporation mother liquor, wherein c (SO) in the sodium sulfate evaporation mother liquor4 2-) 48000mg/L, c (Cl)-) 172000 mg/L;
feeding the RO concentrated water obtained in the reverse osmosis filtration in the second procedure into a sodium chloride evaporation crystallizer 5-2 for evaporation crystallization to obtain sodium chloride crystal salt and sodium chloride evaporation mother liquor, wherein c (Cl) in the sodium chloride evaporation mother liquor-) 180000mg/L, c (SO)4 2-) 46000 mg/L;
and step four, mixing and adding medicine: feeding sodium sulfate evaporation mother liquor and sodium chloride evaporation mother liquor obtained in the sodium sulfate crystal and sodium chloride crystal in the working procedure and RO product water obtained in reverse osmosis filtration in the working procedure II into a mother liquor mixing tank 10 for mixing and homogenizing, wherein the RO product water amount entering the mother liquor mixing tank 10 is equal to the sodium sulfate evaporation mother liquor and the sodium chloride evaporation mother liquor entering the mother liquor mixing tank 10, and the sodium sulfate evaporation mother liquor and the sodium chloride evaporation mother liquor are diluted to prevent the sodium sulfate and the sodium chloride from being separated out due to the temperature reduction of the sodium sulfate evaporation mother liquor and the sodium chloride evaporation mother liquor after entering the mother liquor mixing tank 10; adding hydrochloric acid into the mother liquor mixing tank 10 from a medicine adding tank 11 to obtain a mixed solution with the pH maintained at 8.2 so as to reduce the solubility of silicon in the mixed solution;
and a fifth step of filtering and removing silicon: sending the mixed solution obtained in the mixing and adding of the step four into a filtering device 7, filtering, removing silicon precipitates separated out from the mixed solution, and obtaining silicon-removed water, wherein c (Si) in the silicon-removed water is 130 mg/L;
and (3) carrying out secondary nanofiltration salt separation: feeding RO produced water obtained in the reverse osmosis filtration in the second procedure and silicon-removed water obtained in the silicon removal filtration in the fifth procedure into a secondary nanofiltration membrane device 6, and performing secondary nanofiltration treatment to obtain secondary nanofiltration produced water and secondary nanofiltration concentrated water; the RO water yield entering the secondary nanofiltration membrane device 6 is equal to the silicon removal water yield entering the secondary nanofiltration membrane device 6, and the RO water yield is used for diluting the silicon concentration, so that the c (Si) in the water entering the secondary nanofiltration membrane device 6 is 65mg/L, and the water inlet requirement of the secondary nanofiltration membrane device 6 is met; c (SO) in concentrated water of secondary nanofiltration4 2-) 85000mg/L, returning the water produced by the secondary nanofiltration to sodium trithionate crystal and sodium chloride crystal in the working procedure, and carrying out sodium chloride crystallization treatment;
step seven miscellaneous salt crystallization: and (3) feeding the secondary nanofiltration concentrated water obtained in the secondary nanofiltration salt separation in the step six into a mixed salt evaporation crystallizer 8-2 of a system for improving the recycling rate of sodium chloride in the nanofiltration salt separation to perform evaporation crystallization to obtain mixed salt.
Example 4:
the process for treating high-salinity wastewater by using the high-salinity wastewater treatment system for improving the sodium chloride recycling rate in embodiment 1 comprises the following steps of: the process comprises the steps of one-stage nanofiltration salt separation; reverse osmosis filtration in the second procedure; step (3) sodium trithione crystallization and sodium chloride crystallization; step four, mixing and adding medicine; step five, filtering and removing silicon; the sixth step of secondary nanofiltration salt separation; step seven, crystallizing miscellaneous salt; wherein:
the process comprises the following steps of (1) one-stage nanofiltration salt separation: adjusting the pH value of the adjusting tank 1 to 8, the TDS to 50000mg/L, and the concentration of c (SO)4 2-) Is 5000mg/L, c (SO)4 2-):c(Cl-) High-salinity wastewater with the concentration of 0.9 and the concentration of c (Si) of 20mg/L, COD mg/L and the concentration of 200mg/L is sent into a first-stage nanofiltration membrane device 2 of a high-salinity wastewater treatment system for improving the resource rate of sodium chloride, and first-stage nanofiltration treatment is carried out to obtain first-stage nanofiltration product water and first-stage nanofiltration concentrated water, SO that sulfate ions are enriched in the first-stage nanofiltration concentrated water, and c (SO) in the first-stage nanofiltration concentrated water4 2-) 90000mg/L of water produced by the first-stage nanofiltration-) 12000 mg/L;
and (2) reverse osmosis filtration: the first-stage nanofiltration product water obtained in the first-stage nanofiltration salt separation of the working procedures is sent into an RO membrane device 4 for reverse osmosis filtration treatment, ions in the first-stage nanofiltration product water are further concentrated to obtain RO concentrated water and RO product water, the TDS in the RO concentrated water is 52000mg/L, and c (Cl) in the RO concentrated water-) 23000 mg/L;
step (2), sodium trithionate crystallization and sodium chloride crystallization: feeding the first-stage nanofiltration concentrated water obtained in the step of one-stage nanofiltration salt separation into a sodium sulfate evaporative crystallizer 3-2 for evaporative crystallization to obtain sodium sulfate crystalline salt and sodium sulfate evaporation mother liquor, wherein c (SO) in the sodium sulfate evaporation mother liquor4 2-) Is 48000mg/L，c(Cl-) 170000 mg/L;
feeding the RO concentrated water obtained in the reverse osmosis filtration in the second procedure into a sodium chloride evaporation crystallizer 5-2 for evaporation crystallization to obtain sodium chloride crystal salt and sodium chloride evaporation mother liquor, wherein c (Cl) in the sodium chloride evaporation mother liquor-) 180000mg/L, c (SO)4 2-) 45000 mg/L;
and step four, mixing and adding medicine: feeding sodium sulfate evaporation mother liquor and sodium chloride evaporation mother liquor obtained in the sodium sulfate crystal and sodium chloride crystal in the working procedure and RO product water obtained in reverse osmosis filtration in the working procedure II into a mother liquor mixing tank 10 for mixing and homogenizing, wherein the RO product water amount entering the mother liquor mixing tank 10 is equal to the sodium sulfate evaporation mother liquor and the sodium chloride evaporation mother liquor entering the mother liquor mixing tank 10, and the sodium sulfate evaporation mother liquor and the sodium chloride evaporation mother liquor are diluted to prevent the sodium sulfate and the sodium chloride from being separated out due to the temperature reduction of the sodium sulfate evaporation mother liquor and the sodium chloride evaporation mother liquor after entering the mother liquor mixing tank 10; adding hydrochloric acid into the mother liquor mixing tank 10 from a medicine adding tank 11 to obtain a mixed solution with the pH maintained at 8.3 so as to reduce the solubility of silicon in the mixed solution;
and a fifth step of filtering and removing silicon: sending the mixed solution obtained in the mixing and adding of the step four into a filtering device 7, filtering, removing silicon precipitates separated out from the mixed solution, and obtaining silicon-removed water, wherein c (Si) in the silicon-removed water is 140 mg/L;
and (3) carrying out secondary nanofiltration salt separation: feeding RO produced water obtained in the reverse osmosis filtration in the second procedure and silicon-removed water obtained in the silicon removal filtration in the fifth procedure into a secondary nanofiltration membrane device 6, and performing secondary nanofiltration treatment to obtain secondary nanofiltration produced water and secondary nanofiltration concentrated water; the RO water yield entering the secondary nanofiltration membrane device 6 is equal to the silicon removal water yield entering the secondary nanofiltration membrane device 6, and the RO water yield is used for diluting the silicon concentration, so that the c (Si) in the water entering the secondary nanofiltration membrane device 6 is 70mg/L, and the water inlet requirement of the secondary nanofiltration membrane device 6 is met; c (SO) in concentrated water of secondary nanofiltration4 2-) The concentration of the water produced by the secondary nanofiltration is 95000mg/L, and the water is returned to the sodium trithionate crystal and the sodium chloride crystal in the working procedure for sodium chloride crystallization treatment;
step seven miscellaneous salt crystallization: and (3) feeding the secondary nanofiltration concentrated water obtained in the secondary nanofiltration salt separation in the sixth procedure into a mixed salt evaporative crystallizer 8-2 for evaporative crystallization to obtain mixed salt.
The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.
Claims (5)
1. The high-salinity wastewater treatment system for improving the resource utilization rate of sodium chloride is characterized by comprising an adjusting tank, a primary nanofiltration membrane device, a sodium sulfate evaporative crystallization unit, an RO membrane device, an RO concentrated water tank, a sodium chloride evaporative crystallization unit, a secondary nanofiltration membrane device, a mother liquor mixing tank, a dosing tank, a filtering device and a miscellaneous salt evaporative crystallization unit;
the water outlet of the regulating tank is communicated with the water inlet of the primary nanofiltration membrane device, and the concentrated water outlet of the primary nanofiltration membrane device is communicated with the water inlet of the sodium sulfate evaporation raw water tank of the sodium sulfate evaporation crystallization unit;
the water outlet of the first-stage nanofiltration membrane device is communicated with the water inlet of the RO membrane device, the concentrated water outlet of the RO membrane device is communicated with the water inlet of the RO concentrated water tank, and the water outlet of the RO concentrated water tank is communicated with the water inlet of the sodium chloride evaporation raw water tank of the sodium chloride evaporation crystallization unit;
a mother liquor outlet of a sodium sulfate evaporative crystallizer of the sodium sulfate evaporative crystallization unit and a mother liquor outlet of a sodium chloride evaporative crystallizer of the sodium chloride evaporative crystallization unit are both communicated with a water inlet of the mother liquor mixing tank, a water outlet of the mother liquor mixing tank is communicated with a water inlet of the filtering device, a water outlet of the filtering device is communicated with a water inlet of the secondary nanofiltration membrane device, a water production outlet of the secondary nanofiltration membrane device is communicated with a water inlet of the RO concentrated water tank, and a concentrated water outlet of the secondary nanofiltration membrane device is communicated with a water inlet of an evaporative mother liquor mixing tank of the miscellaneous salt evaporative crystallization unit;
the water outlet of the RO membrane device is divided into two paths to be respectively communicated with the mother liquor mixing tank and the water inlet of the secondary nanofiltration membrane device;
and the medicine outlet of the medicine adding tank is communicated with the water inlet of the mother liquor mixing tank.
2. The high-salinity wastewater treatment system for improving the resource utilization rate of sodium chloride according to claim 1, wherein the sodium sulfate evaporative crystallization unit comprises a sodium sulfate evaporative raw water tank, the sodium sulfate evaporative crystallizer, a sodium sulfate thickener, a sodium sulfate centrifuge, a sodium sulfate drying bed and a sodium sulfate packing machine;
the water outlet of the sodium sulfate evaporation raw water tank is communicated with the inlet of the sodium sulfate evaporation crystallizer, the crystal slurry outlet of the sodium sulfate evaporation crystallizer is communicated with the inlet of the sodium sulfate thickener, the crystal slurry outlet of the sodium sulfate thickener is communicated with the inlet of the sodium sulfate centrifugal machine, the crystallized salt outlet of the sodium sulfate centrifugal machine is communicated with the inlet of the sodium sulfate drying bed, and the outlet of the sodium sulfate drying bed is communicated with the inlet of the sodium sulfate packing machine.
3. The high-salinity wastewater treatment system for improving the resource utilization rate of sodium chloride according to claim 1, wherein the sodium chloride evaporative crystallization unit comprises a sodium chloride evaporative raw water tank, a sodium chloride evaporative crystallizer, a sodium chloride thickener, a sodium chloride centrifuge, a sodium chloride drying bed and a sodium chloride packing machine;
the water outlet of the sodium chloride evaporation raw water tank is communicated with the water inlet of the sodium chloride evaporation crystallizer, the crystal slurry port of the sodium chloride evaporation crystallizer is communicated with the inlet of the sodium chloride thickener, the crystal slurry outlet of the sodium chloride thickener is communicated with the inlet of the sodium chloride centrifugal machine, the crystal salt outlet of the sodium chloride centrifugal machine is communicated with the inlet of the sodium chloride drying bed, and the outlet of the sodium chloride drying bed is communicated with the inlet of the sodium chloride packing machine.
4. The high-salinity wastewater treatment system for improving the resource utilization rate of sodium chloride according to claim 1, wherein the miscellaneous salt evaporation and crystallization unit comprises an evaporation mother liquor mixing tank, a miscellaneous salt evaporation crystallizer, a miscellaneous salt centrifuge, a miscellaneous salt dryer and a miscellaneous salt packaging machine;
the water outlet of the evaporation mother liquor mixing tank is communicated with the water inlet of the miscellaneous salt evaporation crystallizer, the mother liquor outlet of the miscellaneous salt evaporation crystallizer is communicated with the inlet of the miscellaneous salt centrifuge, the crystallized salt outlet of the miscellaneous salt centrifuge is communicated with the inlet of the miscellaneous salt dryer, and the outlet of the miscellaneous salt dryer is communicated with the inlet of the miscellaneous salt packaging machine.
5. The process for treating high-salinity wastewater by using the high-salinity wastewater treatment system for improving the sodium chloride recycling rate as claimed in any one of claims 1 to 4 is characterized by comprising the following steps of: the process comprises the steps of one-stage nanofiltration salt separation; reverse osmosis filtration in the second procedure; step (3) sodium trithione crystallization and sodium chloride crystallization; step four, mixing and adding medicine; step five, filtering and removing silicon; the sixth step of secondary nanofiltration salt separation; step seven, crystallizing miscellaneous salt; wherein:
the process comprises the following steps of one-stage nanofiltration salt separation: adjusting the pH value in the adjusting tank to 6-9, wherein TDS is more than or equal to 40000mg/L, c (SO)4 2-)≥5000mg/L，c(SO4 2-):c(Cl-) Sending the high-salinity wastewater with the concentration of less than or equal to 1, the concentration of c (Si) less than or equal to 20mg/L and the concentration of COD less than or equal to 450mg/L into a first-stage nanofiltration membrane device of a high-salinity wastewater treatment system for improving the resource rate of sodium chloride, and carrying out first-stage nanofiltration salt separation treatment to obtain first-stage nanofiltration product water and first-stage nanofiltration concentrated water SO as to enrich sulfate ions in the first-stage nanofiltration concentrated water and concentrate c (SO) in the first-stage nanofiltration concentrated water4 2-) 80000-100000 mg/L;
reverse osmosis filtration in the second procedure: sending the primary nanofiltration product water obtained in the primary nanofiltration salt separation in the first step into an RO membrane device for reverse osmosis filtration treatment, further concentrating ions in the primary nanofiltration product water to obtain RO concentrated water and RO product water, wherein the TDS in the RO concentrated water is more than 50000 mg/L;
the procedure comprises the following steps of sodium trithionate crystallization and sodium chloride crystallization: sending the first-stage nanofiltration concentrated water obtained in the first-stage nanofiltration salt separation of the procedure into a sodium sulfate evaporation crystallizer for evaporation crystallization to obtain sodium sulfate crystallized salt and sodium sulfate evaporation mother liquor, wherein c (SO) in the sodium sulfate evaporation mother liquor4 2-)＝48000mg/L，c(Cl-) 160000-180000 mg/L;
feeding the RO concentrated water obtained in the reverse osmosis filtration in the second procedure into a sodium chloride evaporation crystallizer for evaporation crystallization to obtain sodium chloride crystal salt and sodium chloride evaporation mother liquor c (Cl)-) 180000mg/L, sodium chloride evaporated c (SO) in mother liquor4 2-)≤48000mg/L；
The fourth step is mixing and adding medicine: feeding sodium sulfate evaporation mother liquor and sodium chloride evaporation mother liquor obtained in the sodium sulfate crystal and sodium chloride crystal in the working procedure and RO product water obtained in reverse osmosis filtration in the working procedure II into a mother liquor mixing tank for mixing and homogenizing, wherein the RO product water amount entering the mother liquor mixing tank is 1-3 times of the total amount of the sodium sulfate evaporation mother liquor and the sodium chloride evaporation mother liquor entering the mother liquor mixing tank, and diluting the sodium sulfate evaporation mother liquor and the sodium chloride evaporation mother liquor to prevent the sodium sulfate evaporation mother liquor and the sodium chloride evaporation mother liquor from being separated out due to the temperature reduction of the sodium sulfate evaporation mother liquor and the sodium chloride evaporation mother liquor after entering the mother liquor mixing tank; adding hydrochloric acid into the mother liquor mixing tank through a medicine adding tank to obtain a mixed solution with the pH of 8-8.5 so as to reduce the solubility of silicon in the mixed solution;
and the fifth step is to filter and remove silicon: sending the mixed solution obtained in the mixing and adding of the step four into a filtering device for filtering treatment, removing silicon precipitates separated out from the mixed solution to obtain silicon-removed water, wherein c (Si) in the silicon-removed water is less than or equal to 150 mg/L;
the six-stage nanofiltration salt separation of the working procedure: feeding RO produced water obtained in the reverse osmosis filtration in the second procedure and silicon-removed water obtained in the silicon removal filtration in the fifth procedure into a secondary nanofiltration membrane device, and performing secondary nanofiltration salt separation treatment to obtain secondary nanofiltration produced water and secondary nanofiltration concentrated water; the concentration of silicon is diluted by RO produced water, so that c (Si) in the water entering the secondary nanofiltration membrane device is less than or equal to 75mg/L, and the water inlet requirement of the secondary nanofiltration membrane device is met; c (SO) in concentrated water of secondary nanofiltration4 2-) 80000-100000 mg/L of the secondary nanofiltration water production is returned to the sodium trithionate crystal and the sodium chloride crystal in the working procedure for sodium chloride crystallization treatment;
the process comprises the following steps: and (3) feeding the secondary nanofiltration concentrated water obtained in the secondary nanofiltration salt separation in the sixth procedure into a mixed salt evaporation crystallizer for evaporation crystallization to obtain mixed salt.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910261285.7A CN111153537B (en) | 2019-04-02 | 2019-04-02 | High-salt wastewater treatment system and process for improving sodium chloride recycling rate |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910261285.7A CN111153537B (en) | 2019-04-02 | 2019-04-02 | High-salt wastewater treatment system and process for improving sodium chloride recycling rate |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN111153537A true CN111153537A (en) | 2020-05-15 |
| CN111153537B CN111153537B (en) | 2023-10-31 |
Family
ID=70555628
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910261285.7A Active CN111153537B (en) | 2019-04-02 | 2019-04-02 | High-salt wastewater treatment system and process for improving sodium chloride recycling rate |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN111153537B (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112110593A (en) * | 2020-10-12 | 2020-12-22 | 江苏迈安德节能蒸发设备有限公司 | TDI industrial wastewater's resourceful treatment system |
| CN112607750A (en) * | 2021-01-12 | 2021-04-06 | 导洁(北京)环境科技有限公司 | System and process for co-producing sodium sulfate and sodium chloride by using flue gas dry desulfurization waste residues |
| CN113173674A (en) * | 2021-05-24 | 2021-07-27 | 陕西省石油化工研究设计院 | High-salinity concentrated water recycling treatment system and method |
| CN115872567A (en) * | 2022-12-29 | 2023-03-31 | 中国天辰工程有限公司 | Salt separation zero-emission process and system with low miscellaneous salt rate and high salt and nitrate quality |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107619144A (en) * | 2017-10-20 | 2018-01-23 | 侯新春 | A kind of high slat-containing wastewater divides salt process for reclaiming and system |
| CN207525017U (en) * | 2017-09-22 | 2018-06-22 | 内蒙古久科康瑞环保科技有限公司 | High slat-containing wastewater step nanofiltration divides salt treatment system |
| CN209740903U (en) * | 2019-04-02 | 2019-12-06 | 内蒙古晶泰环境科技有限责任公司 | high-salinity wastewater treatment system for improving sodium chloride recycling rate |
-
2019
- 2019-04-02 CN CN201910261285.7A patent/CN111153537B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN207525017U (en) * | 2017-09-22 | 2018-06-22 | 内蒙古久科康瑞环保科技有限公司 | High slat-containing wastewater step nanofiltration divides salt treatment system |
| CN107619144A (en) * | 2017-10-20 | 2018-01-23 | 侯新春 | A kind of high slat-containing wastewater divides salt process for reclaiming and system |
| CN209740903U (en) * | 2019-04-02 | 2019-12-06 | 内蒙古晶泰环境科技有限责任公司 | high-salinity wastewater treatment system for improving sodium chloride recycling rate |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112110593A (en) * | 2020-10-12 | 2020-12-22 | 江苏迈安德节能蒸发设备有限公司 | TDI industrial wastewater's resourceful treatment system |
| CN112110593B (en) * | 2020-10-12 | 2023-04-07 | 江苏迈安德节能蒸发设备有限公司 | TDI industrial wastewater's resourceful treatment system |
| CN112607750A (en) * | 2021-01-12 | 2021-04-06 | 导洁(北京)环境科技有限公司 | System and process for co-producing sodium sulfate and sodium chloride by using flue gas dry desulfurization waste residues |
| CN113173674A (en) * | 2021-05-24 | 2021-07-27 | 陕西省石油化工研究设计院 | High-salinity concentrated water recycling treatment system and method |
| CN115872567A (en) * | 2022-12-29 | 2023-03-31 | 中国天辰工程有限公司 | Salt separation zero-emission process and system with low miscellaneous salt rate and high salt and nitrate quality |
Also Published As
| Publication number | Publication date |
|---|---|
| CN111153537B (en) | 2023-10-31 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN111153537A (en) | High-salinity wastewater treatment system and process for improving sodium chloride recycling rate | |
| CN108623104A (en) | High-salinity wastewater zero-discharge treatment method and device based on nanofiltration membrane blending | |
| JP5166034B2 (en) | Method for crystallizing soluble salt of divalent anion from salt water | |
| CN104193067B (en) | Method and device for treating heparin sodium casing producing wastewater | |
| CN104140174A (en) | Combined treatment method for ammonia chloride waste water through rare earth extraction separation | |
| CN110342545A (en) | High-salt wastewater divides salt system and its technique | |
| CN209740903U (en) | high-salinity wastewater treatment system for improving sodium chloride recycling rate | |
| CN113716772A (en) | Recycling and zero-discharge process for divalent salt in organic wastewater of synthetic ammonia | |
| TWI798413B (en) | Treating method and treating device for polarizer manufacturing waste liquid | |
| CN208667421U (en) | High salt waste water zero release processing apparatus based on receive filter membrane allotment | |
| CN111153538B (en) | High-salt wastewater treatment system capable of guaranteeing stable operation of salt and nitrate co-production and process thereof | |
| CN108726756B (en) | Method for treating ammonium salt-containing wastewater | |
| JP2021531225A (en) | Methods and systems for preparing lithium carbonate from lithium ore | |
| CN110451529A (en) | A kind of method of purification of sodium chloride for injection | |
| CN111153540B (en) | Salt separation system and technology for guaranteeing quality of high-salt wastewater crystalline salt | |
| CN209940737U (en) | Salt separation system for ensuring quality of high-salinity wastewater crystal salt | |
| CN213011990U (en) | Production device for purifying and separating potassium sulfate from light salt water | |
| CN112607890B (en) | Zero-discharge water treatment process for high-salt-content water containing calcium and magnesium ions | |
| CN209778557U (en) | High-salinity wastewater treatment system capable of ensuring stable operation of salt and nitrate co-production | |
| CN210559423U (en) | Thermal denitration system for dechlorination light salt brine | |
| CN112777815A (en) | Treatment method and treatment system for salt-containing water | |
| CN113929121A (en) | Method for extracting magnesium sulfate from seawater | |
| CN114105797A (en) | Method for recovering D-p-hydroxyphenylglycine from crystallization mother liquor | |
| CN208667351U (en) | Pulping and papermaking wastewater zero-discharge softening device | |
| CN103435226B (en) | Comprehensive treatment technology for formation water in natural gas extraction |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |