CN215403604U - High COD waste water's of high salt recovery and zero release processing apparatus - Google Patents

Abstract

A high salt and high COD wastewater recovery and zero discharge treatment device comprises a salting-out unit, a rectification unit, an ozone oxidation unit, an evaporation concentration unit and a sheeting unit; adding wastewater and a solvent into a salting-out unit, wherein the salting-out unit is connected with a rectifying unit, the rectifying unit is connected with an ozone oxidation unit, the rectifying unit is connected with an evaporation and concentration unit, and the evaporation and concentration unit is connected with a sheeting unit. The process can meet the requirement of industrial salts, the recovery rate is more than 90 percent, the effluent is further concentrated and reduced, the biochemical requirement can be met, the process is reliable, the operation is simple and convenient, the operation elasticity is high, the equipment investment is low, and the energy consumption in the treatment process is low. The process is suitable for treating high-salinity high-COD wastewater generated in various industries, and realizes zero discharge of wastewater.

Description

High COD waste water's of high salt recovery and zero release processing apparatus

Technical Field

The utility model belongs to the technical field of industrial wastewater treatment, and particularly relates to a high-salinity high-COD wastewater recovery and zero-discharge treatment device.

Background

The living of any living things on the earth can not be boiled, water resources are the most basic condition for sustainable development of the earth ecosystem, and the protection of the water resources is the most important thing to be done by human beings. The concentration and decrement of the wastewater generated in the chemical process are usually carried out firstly, the concentrated high-salt high-COD wastewater treatment process technology is always a bottleneck problem in the water treatment field, and with the increasing requirements of human beings on environmental protection, how to treat the high-salt high-concentration organic wastewater becomes a problem which needs to be solved urgently at present. The high-salt and high-COD wastewater is extremely difficult to degrade, and the wastewater with COD higher than 2000mg/L and biodegradability coefficient lower than 0.3 is generally called high-concentration refractory organic wastewater. High-salt high-concentration organic wastewater generally has special smell, carcinogenic effect, strong chemical stability, low biochemical property and the like, and can cause great harm to human bodies and aquatic organisms if discharged into a water body without any treatment. The high-salt high-concentration organic wastewater has complex components, wherein toxic organic compounds have great threat to human health, and phenols in the wastewater can cause damage to the nervous system of a human body, so that the human body has nervous symptoms of dizziness, headache, uneasiness and the like. Heavy metals in wastewater enter the human body through the food chain causing damage to the brain, nervous system, cardiovascular and liver, and this damage is irreversible. Aromatic compounds in the wastewater can cause great harm to the central nervous system, hematopoietic organs and reproductive system of a human body. The high-salt high-concentration organic wastewater can directly cause water loss of plant cells to influence normal growth of plants and even cause death. High-salt high-concentration organic wastewater can cause serious harm to soil and water, and a large amount of inorganic salt causes soil salinization after the wastewater enters the soil, so that the pH value, the salt content and the like of the soil are changed, the physicochemical property of the soil is influenced, and the soil fertility is reduced, and the soil is not suitable for cultivation. After the high-salt high-concentration organic wastewater enters the water body, on one hand, the osmotic pressure of the water body is increased by a large amount of inorganic salt, which is not beneficial to the growth and reproduction of aquatic organisms. On the other hand, a large amount of organic matters in the wastewater can consume a large amount of dissolved oxygen in the water, so that the water body is anoxic, and the death of fishes and other aquatic organisms is caused.

The high-salt high-concentration organic wastewater has quite wide sources and is ubiquitous in the industries of chlor-alkali, electroplating, chemical industry, food processing, printing and dyeing, medicines, pesticides, papermaking and the like, and the wastewater usually contains a large amount of Na⁺、K⁺、Cl^-1、SO₄ ^2-、CO₃ ^2-And other salt substances, and aromatic and other toxic organic substances. High salt content and high COD are typical characteristics of the wastewater, the salt content of some wastewater is even more than 20%, and the COD is more about 15000mg/L, and based on the characteristics, the ideal effect of directly treating the wastewater by a biochemical method is difficult to achieve, and the method is not feasible. Mainly because the organic matters in the wastewater are mostly refractory organic matters and have strong stability, common microorganisms are difficult to decompose the organic matters, and a great deal of time is needed for domesticating the microorganisms. And the existence of a large amount of inorganic salt in the wastewater enables the activity of the metabolic enzyme of the microorganism to be inhibited, and the microorganism grows slowly, thereby inhibiting the biochemical treatment effect. In the actual treatment process, a process of biochemical treatment after dilution is mostly adopted, however, the process can not remove inorganic salts in water, and a large amount of clean water is consumed when high-concentration wastewater is encountered, so that the process is obviously not suitable. How to remove inorganic salts and organic matters in the wastewater becomes a key for treating the wastewater.

Common methods for removing inorganic salts from wastewater include: evaporation, ion exchange, membrane technology, ultrafiltration, electrodialysis, reverse osmosis, and the like. As an old and practical purification technology, the evaporation technology is very common in the treatment of high-salinity wastewater due to the simple and practical process characteristics. Although the evaporation process is adopted, the salinity and organic matters in the concentrated solution can be separated from the water phase, thereby achieving the purposes of reduction and desalination. However, the residual evaporation liquid is high-concentration and high-salt organic wastewater, and is treated by a spray furnace incineration method or a drying method, so that the energy consumption and the treatment cost are high, and the equipment investment is large; if the crystallization process is adopted for disposal, the crystallization process can be influenced by high-concentration organic matters in the concentrated solution, and the special curing agent is adopted in the curing process, so that the pollutants are bound, meanwhile, the strength can be prepared according to project requirements, and the salt and the organic matters are effectively prevented from overflowing. Methods such as ion exchange and membrane techniques can effectively separate contaminants and salts from water, but such techniques are costly and poorly reproducible. Ultrafiltration, electrodialysis and reverse osmosis techniques only separate contaminants from water and do not reduce the total amount of contaminants.

The method for removing the refractory or toxic organic matters in the water mainly comprises the following steps: fenton's method, photocatalytic method, ozone oxidation method, incineration method, wet oxidation method, ultrasonic degradation method, adsorption method, membrane separation technique, activated sludge method, biofilm method, coagulation sedimentation method, anaerobic biological treatment method, and the like. It should be clear that fenton's process is effective in removing organic matter, but does not remove inorganic salts from water, and even introduces new inorganic salts. Photocatalysis has attracted many researchers' attention and has made good progress with its property of using light energy to degrade contaminants, but the photocatalytic process requires a catalyst, which may introduce new contaminants, and photocatalysis has also failed to remove inorganic salts. The photocatalytic method is temporarily stopped in a laboratory stage due to the problems of the utilization efficiency of a light source, the utilization rate of a catalyst, mass transfer, design of a reactor and the like, and a certain time is required from engineering to engineering. After incineration treatment, the components of the smoke are not obviously changed by comparing the smoke components before and after incineration. The ultrasonic treatment method is high in consumption and not common in practical application, and the ultrasonic treatment method is only a method for removing organic matters in water and cannot remove inorganic salts in the water. Adsorption is a common removal method, but the used adsorbent itself becomes a hazardous waste. The components of the high-concentration refractory organic wastewater are very complex, the adsorbent is difficult to select, the application of an adsorption method is limited to a great extent, the regeneration treatment cost of the adsorbent is high, a large amount of resources are consumed for replacing the adsorbent, and secondary pollution is easily caused. The membrane separation technology has high cost and is easy to block a membrane system, organic matters cannot be removed by the membrane separation technology, low-concentration organic wastewater is only concentrated into high-concentration organic wastewater, and the membrane can be directly corroded or blocked by the high-concentration high-salinity organic wastewater treated by the membrane separation technology. The activated sludge process is the most widely used treatment technology in the water treatment industry, and is a water treatment technology mainly using activated sludge. The principle is that various microbial populations in the wastewater are continuously aerated and cultured to form activated sludge, and after the wastewater is mixed with the activated sludge, the activated sludge removes pollutants from the water through self adsorption and oxidation functions, so that the aim of purifying the water quality is fulfilled. The cost for treating the organic wastewater by the activated sludge method is relatively low, but the method also loses the application value in the case of high-salt organic wastewater with higher salt content. The coagulating sedimentation method has higher removal efficiency on substances such as fine suspended matters, colloids and the like, but has poorer treatment effect on water-soluble pollutants. And the secondary pollution of the medicament, large occupied area of the device and the generation of a large amount of sludge difficult to dewater are problems of a coagulating sedimentation method. Ozone, a strong oxidant, itself has a very high redox potential and can degrade organic pollutants by both direct oxidation and indirect oxidation. In an alkaline environment, ozone generates hydroxyl radicals through a series of chain reactions, and the hydroxyl radicals can nonselectively convert complex organic matters into simple organic matters. It does not produce a solid by-product (the final by-product is oxygen) compared to fenton.

Chinese patent 201310202681.5 discloses a method for treating high-salt high-COD wastewater by introducing hydrogen chloride gas to precipitate chloride salt and removing organic matters in the wastewater by introducing chlorine gas to oxidize, wherein the chlorine gas is a highly toxic gas with strong pungent smell and has asphyxiability, the hydrogen chloride used belongs to a strong corrosive liquid, and the technical process is harsh and not environment-friendly.

Chinese patent 201811200967.9 discloses a method for treating high salt and high COD wastewater by using an ultrafiltration membrane filtration device, an electrodialysis treatment device, an oxidation treatment device, a reverse osmosis treatment device and a low temperature evaporation device, wherein the membrane separation technology may directly corrode or block the membrane during the use process, the electrodialysis treatment device has high power consumption, high operating cost, high requirements on electrode materials, and easily damaged electrodes, which are not compatible with the large flux and continuous use required by industrial application, and are not suitable for industrial application.

Chinese patent 201610072832.3 discloses a method for treating high-salt high-COD wastewater by using ozone oxidation to reduce the molecular weight of organic substances in the wastewater and then using activated carbon for adsorption, which is not suitable for large-scale continuous industrial application, and has the disadvantages of high regeneration treatment cost of the adsorbent, large resource consumption for replacing the adsorbent, easy secondary pollution, etc.

Chinese patent 201810666249.4 discloses a method for treating high-salt high-COD wastewater by adopting an effective coupling integrated process of reverse osmosis and electrodialysis, which has extremely high pretreatment requirement, large investment and high operation cost and is not suitable for large-scale and continuous industrial application.

In summary, although there are many process technologies for removing high-salt and high-COD wastewater, there are problems of harsh process, environmental pollution, high energy consumption, large investment, high operating cost, inability of large-throughput or continuous use, and unsuitability for large-scale and continuous industrial application. Aiming at the removal of high-salt high-COD wastewater, no industrial application technology which is reliable, effective and economical in technological process exists.

SUMMERY OF THE UTILITY MODEL

Aiming at the defects of the prior art, the utility model aims to provide a high-salinity high-COD wastewater recovery and zero-discharge treatment device, which has the advantages of reliable technological process, capability of meeting the requirements of production tasks of actual enterprises, simple and convenient operation, high operation flexibility, low equipment investment cost and low process energy consumption, and solves the problems of harsh technological process, environmental pollution, high energy consumption, high investment, high operation cost, incapability of large-flux or continuous use, inapplicability to large-scale and continuous industrial application and the like in the prior art.

In order to achieve the purpose, the technical scheme adopted by the utility model is as follows:

a high salt and high COD wastewater recovery and zero discharge treatment device comprises a salting-out unit, a rectification unit, an ozone oxidation unit, an evaporation concentration unit and a sheeting unit; adding wastewater and a solvent into a salting-out unit, wherein the salting-out unit is connected with a rectifying unit, the rectifying unit is connected with an ozone oxidation unit, the rectifying unit is connected with an evaporation and concentration unit, and the evaporation and concentration unit is connected with a sheeting unit.

The utility model is further improved in that the salting-out unit comprises a waste liquid storage tank, a solvent storage tank, a waste liquid feeding pump, a solvent pump, a salting-out tank and a first centrifuge; wherein, the waste liquid storage tank links to each other with the jar of salting out through waste liquid charge pump, and the solvent storage tank links to each other with the jar of salting out through the solvent pump, and the jar of salting out links to each other with first centrifuge.

The utility model is further improved in that the salting-out tank is multiple, and the multiple salting-out tanks work in parallel.

The utility model is further improved in that the salting tank is a vertical stirring tank.

The utility model has the further improvement that the rectifying unit comprises a first centrifugal mother liquor tank, a first centrifugal mother liquor pump, a stator-rotor rectifier, a first condenser, a tower top reflux tank, a tower top collecting pump, a tower bottom reboiler and a tower bottom collecting pump; wherein, the inlet of a first centrifugal mother liquor tank is connected with the salting-out unit, the outlet of the first centrifugal mother liquor tank is connected with a stator-rotor rectifier through a first centrifugal mother liquor pump, the outlet at the top of the stator-rotor rectifier is connected with a first condenser, the first condenser is connected with a tower top reflux tank, and the tower top reflux tank is connected with the stator-rotor rectifier; the bottom outlet of the stator-rotor rectifier is connected with a tower kettle reboiler, and the tower kettle reboiler is connected with a tower kettle collecting pump.

The utility model is further improved in that the reboiler at the tower bottom is a tubular heat exchanger.

The utility model has the further improvement that the ozone oxidation unit comprises a pH adjusting tank, an oxidation tower, an oxidation circulating pump, an ozone unit, an oxidation waste liquid storage tank and an oxidation waste liquid pump; wherein, the rectifying unit is connected with the inlet of the pH adjusting tank, and the outlet of the pH adjusting tank is connected with the oxidizing waste liquid pump through the oxidizing tower and the oxidizing waste liquid storage tank.

The utility model has the further improvement that the oxidation tower is connected with an oxidation circulating pump and an ozone unit; the oxidation tower is a vertical packed tower, and the packing type is pall ring.

The utility model has the further improvement that the evaporation concentration unit comprises a second condenser, a first-effect evaporator, a third condenser, circulating water inlet, circulating water outlet, a first-effect circulation extraction pump, a second-effect evaporator, a second-effect steam extraction pump, a first-effect and second-effect steam condensation water tank, a second-effect circulation extraction pump and a biochemical treatment device; wherein, the inlet of the second condenser is connected with the ozone oxidation unit, the outlet of the second condenser is divided into two paths, one path is connected with the first-effect and second-effect steam condensate water tanks, and the first-effect and second-effect steam condensate water tanks are connected with the biochemical treatment device; the other path is connected with an inlet of the first-effect evaporator, an outlet at the top of the first-effect evaporator is connected with a second condenser, an outlet at the bottom of the second condenser is connected with an inlet of the first-effect circulating extraction pump, an outlet of the first-effect circulating extraction pump is divided into two paths, the inlet of the first-effect evaporator at one path is connected, and the other path is connected with the second-effect evaporator; the outlet at the top of the double-effect evaporator is connected with the inlet of a double-effect steam extraction pump, and the outlet of the double-effect steam extraction pump is connected with the single-effect evaporator; the bottom outlet of the second-effect evaporator is connected with a second-effect circulating extraction pump.

The utility model has the further improvement that the sheeting unit comprises a hydrocyclone, a stirring crystallizer, a second centrifuge mother liquor tank, a second centrifuge mother liquor pump, a sheeting machine and a solid landfill device; wherein, the hydrocyclone inlet links to each other with the evaporation concentration unit, and hydrocyclone top export links to each other with the entry of two effect steam extraction pump, and hydrocyclone bottom export links to each other with stirring crystallizer entry, and stirring crystallizer export links to each other with the second centrifuge entry, and the second centrifuge links to each other with second centrifugation mother liquor jar, and second centrifugation mother liquor jar links to each other with the entry of second centrifugation mother liquor pump, and the export of second centrifugation mother liquor pump divide into two the tunnel, links to each other with two effect evaporators all the way, and another way links to each other with the flaker, and the flaker links to each other with solid landfill device.

A high salt and high COD waste water recovery treatment process based on the device comprises the steps of carrying out centrifugal separation and segregation on waste water and solvent after salting out by a salting-out unit to obtain crystallized salt and centrifugal mother liquor, carrying out desolventizing treatment on the centrifugal mother liquor by a rectifying unit, then adjusting pH, then, feeding the centrifugal mother liquor into an ozone oxidation unit for degradation, feeding a concentrated solution containing solid-phase salt generated after the degraded oxidation waste liquid is concentrated by an evaporation and concentration unit into a flaking unit, and carrying out flaking treatment by the flaking unit and then carrying out landfill treatment.

Compared with the prior art, the utility model has the beneficial effects that: compared with evaporation, the solvent salting-out has the advantages of lower energy consumption, simple process and better salt recovery rate and quality in the wastewater. According to the utility model, salts in the high-salt high-COD wastewater and organic matters in the ozone oxidation degradation wastewater are removed and recovered firstly, and then evaporation concentration reduction is carried out, so that the influence of a large amount of organic matters in the high-salt high-COD wastewater on evaporation efficiency can be avoided, when the content of the organic matters in the wastewater is higher, the wastewater becomes viscous when the evaporation concentration is carried out to a certain degree, further evaporation cannot be carried out, the evaporation efficiency is improved, and the energy consumption is lower. The utility model can realize zero discharge of wastewater, and is particularly suitable for zero discharge of high-salinity high-COD wastewater after concentration.

The utility model provides a salting-out, ozone oxidation and evaporation concentration process for high-salt and high-COD wastewater difficult to treat, which can achieve the purposes of removing and recovering salts in the wastewater, concentrating and reducing the wastewater and enabling the effluent to meet the requirements of biochemical treatment. The process can meet the requirement of industrial salts, the recovery rate is more than 90 percent, the effluent is further concentrated and reduced, the biochemical requirement can be met, the process is reliable, the operation is simple and convenient, the operation elasticity is high, the equipment investment is low, and the energy consumption in the treatment process is low. The process is suitable for treating high-salinity high-COD wastewater generated in various industries, and realizes zero discharge of wastewater. The method for treating the high-salt high-COD wastewater is reliable in process, meets the requirements of production tasks of actual enterprises, is simple and convenient to operate, high in operation elasticity, low in equipment investment cost and low in process energy consumption, and solves the problems that the process is harsh, not environment-friendly, high in energy consumption, large in investment, high in operation cost, incapable of being used in large-flux or continuous mode, not suitable for large-scale and continuous industrial application and the like in the prior art.

Drawings

FIG. 1 is a schematic process flow diagram of the present invention.

FIG. 2 is a schematic diagram of the apparatus of the present invention.

In the figure, 1, a waste liquid storage tank; 2. a solvent storage tank; 3. a waste liquid feed pump; 4. a solvent pump; 5. salting out a tank; 6. a first centrifuge; 7. recovering salt from the solid; 8. a first centrifuge mother liquor tank; 9. a first centrifuge mother liquor pump; 10. a stator-rotor rectifier; 11. A first condenser; 12. a top reflux drum; 13. a tower top collection pump; 14. a tower kettle reboiler; 15. a tower kettle collecting pump; 16. A pH adjusting liquid; 17. a pH adjusting tank; 18. an oxidation tower; 19. an oxidation circulation pump; 20. an ozone unit; 21. an oxidation waste liquid storage tank; 22. an oxidation waste liquid pump; 23. a second condenser; 24. a first-effect evaporator; 25. a third condenser; 26. circulating water to enter; 27. circulating water is discharged; 28. a first effect circulation extraction pump; 29. a second effect evaporator; 30. a secondary steam extraction pump; 31. a first effect and a second effect steam condensate tank; 32. a two-effect circulating extraction pump; 33. biochemical treatment; 34. a hydrocyclone separator; 35. stirring a crystallizer; 36. a second centrifuge; 37. salt pollution; 38. a second centrifuge mother liquor tank; 39. a second centrifuge mother liquor pump; 40. sheeting machine; 41. solid landfill device.

Detailed Description

The following detailed description of embodiments of the utility model refers to the accompanying drawings. It should be understood that the detailed description and specific examples, while indicating the present invention, are given by way of illustration and explanation only, not limitation.

Because the high-salt high-concentration organic wastewater can not adopt the conventional biochemical treatment technology, the utility model provides a salting-out, ozone oxidation and evaporation concentration process for the high-salt high-COD wastewater difficult to treat, and the purposes of removing and recovering the salts in the high-salt high-COD wastewater, concentrating and reducing the wastewater and outputting the water to meet the requirements of biochemical treatment can be achieved.

Referring to fig. 1, the utility model provides a high-salt high-COD wastewater recovery and zero-discharge treatment device, comprising a salting-out unit, a rectifying unit, an ozone oxidation unit, an evaporation concentration unit and a sheeting unit;

the salting-out unit comprises a waste liquid storage tank 1, a solvent storage tank 2, a waste liquid feeding pump 3, a solvent pump 4, a salting-out tank 5 and a first centrifuge 6; wherein, waste liquid storage tank 1 links to each other with salting-out jar 5 through waste liquid charge pump 3, and solvent storage tank 2 links to each other with salting-out jar 5 through solvent pump 4, and salting-out jar 5 links to each other with first centrifuge 6, obtains solid recovery salt 7 after first centrifuge 6 centrifugation.

The rectifying unit comprises a first centrifugal mother liquor tank 8, a first centrifugal mother liquor pump 9, a stator-rotor rectifier 10, a first condenser 11, a tower top reflux tank 12, a tower top collecting pump 13, a tower kettle reboiler 14 and a tower kettle collecting pump 15; wherein, the inlet of the first centrifugal mother liquor tank 8 is connected with the first centrifuge 6, the outlet of the first centrifugal mother liquor tank 8 is connected with the stator-rotor rectifier 10 through the first centrifugal mother liquor pump 9, the outlet of the top of the stator-rotor rectifier 10 is connected with the first condenser 11, the first condenser 11 is connected with the tower top reflux tank 12, the tower top reflux tank 12 is connected with the stator-rotor rectifier 10; the outlet at the bottom of the stator-rotor rectifier 10 is connected with a tower bottom reboiler 14, and the tower bottom reboiler 14 is connected with a tower bottom collection pump 15.

The ozone oxidation unit comprises a pH adjusting liquid 16, a pH adjusting pool 17, an oxidation tower 18, an oxidation circulating pump 19, an ozone unit 20, an oxidation waste liquid storage tank 21 and an oxidation waste liquid pump 22; wherein, the tower bottom collecting pump 15 is connected with the inlet of the pH adjusting tank 17, the pH adjusting tank 17 is also provided with a pH adjusting liquid 16, the outlet of the pH adjusting tank 17 is connected with an oxidation waste liquid pump 22 through an oxidation tower 18 and an oxidation waste liquid storage tank 21, and the oxidation tower 18 is connected with an oxidation circulating pump 19 and an ozone unit 20.

The evaporation concentration unit comprises a second condenser 23, a first-effect evaporator 24, a third condenser 25, a circulating water inlet 26, a circulating water outlet 27, a first-effect circulation extraction pump 28, a second-effect evaporator 29, a second-effect steam extraction pump 30, a first-effect and second-effect steam condensation water tank 31, a second-effect circulation extraction pump 32 and a biochemical treatment device 33; wherein, the inlet of the second condenser 23 is connected with the oxidation waste liquid pump 22, the outlet of the second condenser 23 is divided into two paths, one path is connected with the first-effect and second-effect steam condensate water tank 31, and the first-effect and second-effect steam condensate water tank 31 is connected with the biochemical treatment device 33; the other path is connected with an inlet of a first-effect evaporator 24, an outlet at the top of the first-effect evaporator 24 is connected with a second condenser 23, an outlet at the bottom of the second condenser 23 is connected with an inlet of a first-effect circulating extraction pump 28, an outlet of the first-effect circulating extraction pump 28 is divided into two paths, one path is connected with the inlet of the first-effect evaporator 24, and the other path is connected with a second-effect evaporator 29. The outlet at the top of the second-effect evaporator 29 is connected with the inlet of a second-effect steam extraction pump 30, and the outlet of the second-effect steam extraction pump 30 is connected with the first-effect evaporator 24. The outlet at the bottom of the double-effect evaporator 29 is connected with a double-effect circulation extraction pump 32.

The sheeting unit comprises a hydrocyclone 34, a stirred crystallizer 35, a second centrifuge 36, dirty salt 37, a second centrifuge mother liquor tank 38, a second centrifuge mother liquor pump 39, a sheeting machine 40 and a solids landfill 41. Wherein, the inlet of the hydrocyclone 34 is connected with the double-effect circulation extraction pump 32, the outlet at the top of the hydrocyclone 34 is connected with the inlet of the double-effect steam extraction pump 30, the outlet at the bottom of the hydrocyclone 34 is connected with the inlet of the stirring crystallizer 35, the outlet of the stirring crystallizer 35 is connected with the inlet of the second centrifuge 36, the polluted salt 37 is obtained by centrifuging through the second centrifuge 36, the second centrifuge 36 is connected with the second centrifuge mother liquor tank 38, the second centrifuge mother liquor tank 38 is connected with the inlet of the second centrifuge mother liquor pump 39, the outlet of the second centrifuge mother liquor pump 39 is divided into two paths, one path is connected with the double-effect evaporator 29, the other path is connected with the flaking machine 40, and the flaking machine 40 is connected with the solid landfill device 41.

The salting-out unit comprises a salting-out tank 5, the waste liquid after salting-out is separated out by a first centrifuge 6 to separate out crystal salt and is recovered, and the recovery rate is more than 90%; the centrifugal mother liquor enters a rectification unit for desolventizing treatment, and the rectification unit adopts a stator-rotor rectifier 10 and is connected with a tower kettle reboiler 14 and a first condenser 11; the pH of the waste liquid after the solvent removal enters an ozone oxidation unit, the ozone oxidation unit is provided with an oxidation tower 18, the equipment type of the oxidation tower 18 is a vertical packed tower, the packing type is pall ring, and the oxidation tower 18 is connected with an oxidation circulating pump and an ozone unit; the degraded oxidation waste liquid enters an evaporation concentration unit, multi-effect evaporation is adopted, evaporation condensate water can meet the biochemical requirement and is subjected to biochemical treatment, a concentrated solution containing solid-phase salt generated after concentration is subjected to centrifugal separation after passing through a hydrocyclone and a stirring crystallizer, and a solid phase is extracted and sent out of the home; after the mother liquor is circularly evaporated and concentrated for many times, the COD can reach about 15 percent, and the mother liquor enters a flaking unit to be subjected to landfill treatment after flaking.

Specifically, referring to fig. 2, a waste liquid storage tank 1 is connected with a salting-out tank 5 through a waste liquid feeding pump 3, a solvent storage tank 2 is connected with the salting-out tank 5 through a solvent pump 4, the waste liquid enters a first centrifuge 6 from the bottom of the salting-out tank 5 after being salted out, and a solid recovery salt 7 and a first centrifugal mother liquor 8 are obtained through centrifugation; the first centrifugal mother liquor 8 enters a first centrifugal mother liquor tank 8, the centrifugal mother liquor in the first centrifugal mother liquor tank 8 enters a stator-rotor rectifier 10 through a first centrifugal mother liquor pump 9, light components of a solvent A at the top of the tower in the stator-rotor rectifier 10 flow into a tower top reflux tank 12 after being condensed by a first condenser 11, and the solvent A in the tower top reflux tank 12 enters a solvent storage tank 2 through a tower top collection pump 13; the waste liquid after the rectification by the stator-rotor rectifier 10 passes through a tower kettle reboiler 14 to obtain desolventizing waste liquid, and the desolventizing waste liquid enters a pH adjusting tank 17 through a tower kettle collecting pump 15, and pH adjusting liquid 16 also enters the pH adjusting tank 17. The desolventizing waste liquid enters an oxidation tower 18 after being subjected to pH adjustment in a pH adjusting tank 17, the oxidation tower 18 is connected with an oxidation circulating pump 19 and an ozone unit 20, and the oxidation waste liquid oxidized by the oxidation tower 18 enters an oxidation waste liquid storage tank 21; the oxidized waste liquid in the oxidized waste liquid storage tank 21 enters a second condenser 23 through an oxidized waste liquid pump 22 and is used for cooling steam evaporated from the top of a first-effect evaporator 24, the steam is condensed by a third condenser 25 and then enters a first-effect and second-effect steam condensate water tank 31, the third condenser 25 is connected with a circulating water inlet 26 and a circulating water outlet 27, the oxidized waste liquid enters a first-effect evaporator 24 through the second condenser 23, a first-effect circulating extraction pump 28 is arranged at the bottom of the first-effect evaporator 24, the extracted liquid of the first-effect evaporator 24 continues to enter a second-effect evaporator 29 through the first-effect circulating extraction pump 28, the steam at the top of the second-effect evaporator 29 enters the first-effect evaporator 24 through the second-effect steam extraction pump 30 and is used as a heat source of the first-effect evaporator 24, a second-effect circulating extraction pump 32 is arranged at the bottom of the second-effect evaporator 29, and the liquid at the bottom of the second-effect evaporator 29 enters a hydrocyclone 34 through the second-effect circulating extraction pump 32, the liquid at the bottom of the second condenser 23 and the liquid at the bottom of the third condenser 25 pass through a first-effect steam condensate tank 31 and a second-effect steam condensate tank 31 and then enter a biochemical treatment device 33; the two-effect produced liquid enters a hydrocyclone 34, the top of the hydrocyclone 34 is connected with a first-effect evaporator 24 through a two-effect steam production pump 30, steam at the top of the hydrocyclone 34 is also used as a heat source of the first-effect evaporator 24, concentrated liquid flowing out of the bottom of the hydrocyclone 34 enters a second centrifuge 36 through a stirring crystallizer 35 for centrifugation to obtain polluted salt 37 and centrifugal mother liquid after centrifugation, the centrifugal mother liquid enters a second centrifugal mother liquid tank 38, the centrifugal mother liquid in the second centrifugal mother liquid tank 38 is circularly evaporated for multiple times through a second centrifugal mother liquid pump 39 and then enters a flaking machine 40, and the precipitated liquid is sent to the outside for landfill through a solid landfill device 41 after being flaked through the flaking machine 40.

The recovered salt of the process can meet the requirements of industrial salts, after salting out and centrifugal separation treatment, the salt recovery rate in the wastewater is more than 90 percent and meets the requirements of industrial salts, the rest of polluted salt is sent to the outside for landfill treatment, the effluent is further concentrated and reduced in amount and can meet the biochemical requirements, the process is reliable, the operation is simple and convenient, the operation elasticity is high, the equipment investment is low, and the energy consumption in the treatment process is low. The process is suitable for treating high-salinity high-COD wastewater generated in various industries, and realizes zero discharge of wastewater.

The recovery process is suitable for treating high-salt high-COD wastewater generated in various industries, and is particularly suitable for zero discharge of the concentrated high-salt high-COD wastewater, and the salt type mainly comprises one or more salts of sodium chloride, potassium chloride, calcium chloride, sodium sulfate, sodium carbonate and the like; the salt mass concentration of the high-salt high-COD wastewater is 10-30%, the COD content is 10000 mg/L-20000 mg/L, the pH value is 6-10, and the wastewater amount is 0.5 t/h-2 t/h.

Further, the salt species is sodium sulfate.

The salting-out tank 5 can be provided with a plurality of salting-out tanks working in parallel, the equipment type of the salting-out tank 5 is a vertical stirring tank, the equipment is made of enamel, and the equipment volume is 2-10m³The salting-out tank 5 is provided with two liquid inlets for respectively adding the wastewater and the solvent, and a mechanical stirring device, wherein the stirring speed is 40-100rpm, and the salting-out temperature is 10-80 ℃.

The utility model achieves the purpose of salt precipitation by adding the solvent to reduce the solubility of the salts in the wastewater, and compared with evaporation, the solvent salt precipitation has the advantages of lower energy consumption, simple and convenient process and better salt recovery rate and quality in the wastewater.

The solvent added in the salting-out process is ethanol or methanol, and the mass ratio range of the wastewater to the solvent is (1-5): 1, preferably, the adding mass ratio range of the wastewater to the solvent is (1-2): 1.

the rectifying unit adopts steam stripping rectification to remove the solvent, the rectifying equipment is in the form of a stator-rotor rectifier 10, the stator-rotor rectifier is provided with a tower kettle reboiler 14 and a first condenser 11, centrifugal mother liquor flows from the inner layer to the outer layer of the stator-rotor rectifier 10 and is in countercurrent contact with heating steam, mass and heat transfer are carried out, the solvent in the liquid phase enters the first condenser 11, and the desolventizing waste liquor enters the tower kettle reboiler 14.

Wherein, the centrifugal mother liquor is preheated by heat exchange with the desolventizing waste liquor sent from the tower kettle before entering the rectifier.

The tower kettle reboiler 14 is a BKU tubular heat exchanger (horizontal type), and is heated by steam, the heating steam pressure range is 0.2 MPa-1 MPa, and the heating steam pressure range is 0.5-0.7 MPa.

The oxidation tower 18 is a vertical packing tower, the packing type is pall ring, and the oxidation tower 18 is connected with an oxidation circulating pump and an ozone unit. The ozone output range of the ozone unit is 4-10kg/h, and preferably, the ozone output range is 5-7 kg/h.

Before entering the ozone oxidation unit, the waste liquid after the solvent removal is subjected to pH adjustment by using a pH adjusting solution 16 (liquid caustic soda, namely sodium hydroxide), wherein the mass concentration of the liquid caustic soda is 30-32% or 40-42%, and preferably, the pH of the waste liquid after the solvent removal is subjected to pH adjustment by using liquid caustic soda with the mass concentration of 32%. The pH value of the waste liquid after solvent removal is adjusted by liquid caustic soda is 10-14, preferably, the pH value of the waste liquid after solvent removal is adjusted by liquid caustic soda is 12-14.

The inside of the oxidation tower 18 is divided into 1 to 4 areas, the desolventizing waste liquid is contacted and reacted with ozone in a countercurrent mode step by step, COD in the waste liquid is reduced, and the waste liquid is sent into a concentration unit through an oxidation circulating pump until the waste liquid is oxidized to reach the standard.

The degraded oxidation waste liquid enters an evaporation concentration unit, multi-effect evaporation is carried out by arranging a first-effect evaporator 24 and a second-effect evaporator 29, heat coupling integrated utilization can be realized among the multi-effect evaporation, secondary steam generated in a second-effect evaporation tank can serve as a heat source for a first-effect heater, and the evaporation tank is connected with a circulating pump.

Furthermore, the method adopts the steps of firstly removing and recovering salts in the high-salt high-COD wastewater and oxidizing and degrading organic matters in the wastewater by ozone, and then evaporating, concentrating and reducing, so that the influence of a large amount of organic matters in the high-salt high-COD wastewater on the evaporation efficiency can be avoided, when the content of the organic matters in the wastewater is high, the wastewater becomes viscous and cannot be further evaporated, and the evaporation efficiency is improved.

Furthermore, the evaporation condensate water can meet the biochemical requirement and is sent for biochemical treatment.

Further, the concentrated solution containing solid-phase salt generated after concentration is subjected to centrifugal separation after passing through a hydrocyclone and a stirring crystallizer, and solid-phase polluted salt is extracted and sent to outside for treatment.

Further, after the mother liquor is subjected to cyclic evaporation and concentration for many times, the COD can reach about 15%, and the mother liquor enters a flaking unit and is sent to the outside for landfill treatment after flaking.

Example 1

The method comprises the following steps of (1) carrying out small and medium test on the wastewater, wherein the amount of the wastewater produced by a chemical enterprise is 1t/h, the salt content is 21 percent, the pH value is 9, taking 100mL of the wastewater to place in a 500mL separating funnel, adding 80mL of a solvent A, fully shaking, uniformly mixing, standing for 0.5h, obviously observing precipitated solid salt, carrying out liquid-solid separation by using a centrifugal machine, obtaining the yield of the salt after drying, and distilling a centrifugal mother liquor at 160 ℃ to smoothly evaporate the solvent A; adjusting the pH value of the waste liquid after solvent removal to 13 by using liquid caustic soda with the mass concentration of 32%, and then connecting the waste liquid with an ozone generator, wherein the ozone introduction amount is 40g/L, and the COD removal rate is 82%; and (3) further evaporating and concentrating the oxidation waste liquid, and separating out a very small amount of polluted salt after crystallization and centrifugation.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are included in the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims (10)

1. A high salt and high COD wastewater recovery and zero discharge treatment device is characterized by comprising a salting-out unit, a rectifying unit, an ozone oxidation unit, an evaporation concentration unit and a sheeting unit; adding wastewater and a solvent into a salting-out unit, wherein the salting-out unit is connected with a rectifying unit, the rectifying unit is connected with an ozone oxidation unit, the rectifying unit is connected with an evaporation and concentration unit, and the evaporation and concentration unit is connected with a sheeting unit.

2. The recycling and zero-emission treatment device of high-salinity and high-COD wastewater according to claim 1, characterized in that the salting-out unit comprises a waste liquid storage tank (1), a solvent storage tank (2), a waste liquid feeding pump (3), a solvent pump (4), a salting-out tank (5) and a first centrifuge (6); wherein, the waste liquid storage tank (1) is connected with the salting-out tank (5) through a waste liquid feeding pump (3), the solvent storage tank (2) is connected with the salting-out tank (5) through a solvent pump (4), and the salting-out tank (5) is connected with the first centrifuge (6).

3. The recycling and zero-emission treatment device for high-salinity and high-COD wastewater according to claim 2, characterized in that the salting-out tank (5) is provided in plurality, and a plurality of salting-out tanks are connected in parallel for operation.

4. The recycling and zero discharge treatment device of high salinity and COD wastewater according to claim 2 is characterized in that the salting-out tank (5) is a vertical stirring tank.

5. The recycling and zero emission treatment device of high salinity and high COD wastewater according to claim 1, characterized in that the rectification unit comprises a first centrifuge mother liquor tank (8), a first centrifuge mother liquor pump (9), a stator-rotor rectifier (10), a first condenser (11), an overhead reflux tank (12), an overhead collection pump (13), a kettle reboiler (14) and a kettle collection pump (15); wherein, the inlet of a first centrifugal mother liquor tank (8) is connected with a salting-out unit, the outlet of the first centrifugal mother liquor tank (8) is connected with a stator-rotor rectifier (10) through a first centrifugal mother liquor pump (9), the outlet at the top of the stator-rotor rectifier (10) is connected with a first condenser (11), the first condenser (11) is connected with a tower top reflux tank (12), and the tower top reflux tank (12) is connected with the stator-rotor rectifier (10); the outlet at the bottom of the stator-rotor rectifier (10) is connected with a tower bottom reboiler (14), and the tower bottom reboiler (14) is connected with a tower bottom collection pump (15).

6. The device for recycling and zero emission of high salinity and high COD wastewater according to claim 5, wherein the tower reboiler (14) is a tubular heat exchanger.

7. The recycling and zero emission treatment device of high salinity and COD wastewater according to claim 1, characterized in that the ozone oxidation unit comprises a pH adjusting tank (17), an oxidation tower (18), an oxidation circulating pump (19), an ozone unit (20), an oxidation waste liquid storage tank (21) and an oxidation waste liquid pump (22); wherein, the rectifying unit is connected with the inlet of a pH adjusting tank (17), and the outlet of the pH adjusting tank (17) is connected with an oxidation waste liquid pump (22) through an oxidation tower (18) and an oxidation waste liquid storage tank (21).

8. The recycling and zero emission treatment device of high salinity and high COD wastewater according to claim 7, wherein the oxidation tower (18) is connected with an oxidation circulation pump (19) and an ozone unit (20); the oxidation tower (18) is a vertical packed tower, and the packing type is pall ring.

9. The device for recycling and zero-emission treatment of high-salinity high-COD wastewater according to claim 1, characterized in that the evaporation concentration unit comprises a second condenser (23), a first-effect evaporator (24), a third condenser (25), a circulating water inlet (26), a circulating water outlet (27), a first-effect circulating extraction pump (28), a second-effect evaporator (29), a second-effect steam extraction pump (30), a first-effect and second-effect steam condensation water tank (31), a second-effect circulating extraction pump (32) and a biochemical treatment device (33); wherein, the inlet of the second condenser (23) is connected with the ozone oxidation unit, the outlet of the second condenser (23) is divided into two paths, one path is connected with the first-effect and second-effect steam condensate water tanks (31), and the first-effect and second-effect steam condensate water tanks (31) are connected with the biochemical treatment device (33); the other path is connected with an inlet of a first-effect evaporator (24), an outlet at the top of the first-effect evaporator (24) is connected with a second condenser (23), an outlet at the bottom of the second condenser (23) is connected with an inlet of a first-effect circulating extraction pump (28), an outlet of the first-effect circulating extraction pump (28) is divided into two paths, one path of the inlet of the first-effect evaporator (24) is connected, and the other path of the inlet of the first-effect evaporator (24) is connected with a second-effect evaporator (29); the outlet at the top of the second-effect evaporator (29) is connected with the inlet of a second-effect steam extraction pump (30), and the outlet of the second-effect steam extraction pump (30) is connected with the first-effect evaporator (24); the bottom outlet of the double-effect evaporator (29) is connected with a double-effect circulating extraction pump (32).

10. The recycling and zero-emission treatment device of high-salinity high-COD wastewater according to claim 1, characterized in that the sheeting unit comprises a hydrocyclone (34), a stirred crystallizer (35), a second centrifuge (36), a second centrifuge mother liquor tank (38), a second centrifuge mother liquor pump (39), a sheeting machine (40) and a solid landfill device (41); the inlet of the hydrocyclone (34) is connected with the evaporation concentration unit, the outlet at the top of the hydrocyclone (34) is connected with the inlet of the double-effect steam extraction pump (30), the outlet at the bottom of the hydrocyclone (34) is connected with the inlet of the stirring crystallizer (35), the outlet of the stirring crystallizer (35) is connected with the inlet of the second centrifugal machine (36), the second centrifugal machine (36) is connected with the second centrifugal mother liquor tank (38), the second centrifugal mother liquor tank (38) is connected with the inlet of the second centrifugal mother liquor pump (39), the outlet of the second centrifugal mother liquor pump (39) is divided into two paths, one path is connected with the double-effect evaporator (29), the other path is connected with the sheeting apparatus (40), and the sheeting apparatus (40) is connected with the solid landfill device (41).

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