CN106186550B

CN106186550B - Wastewater resource recovery zero-discharge device and method

Info

Publication number: CN106186550B
Application number: CN201610720100.0A
Authority: CN
Inventors: 孟广祯
Original assignee: Huazi Grant Environmental Protection Technology Beijing Co ltd
Current assignee: Huazi Grant Environmental Protection Technology Beijing Co ltd
Priority date: 2016-08-25
Filing date: 2016-08-25
Publication date: 2025-03-04
Anticipated expiration: 2036-08-25
Also published as: CN106186550A

Abstract

The present invention relates to the technical field of zero-discharge of wastewater resources. The zero-discharge device for wastewater resources includes flocculation and precipitation of impure salts, addition of soda ash to obtain calcium carbonate precipitation, addition of caustic soda to obtain magnesium hydroxide, membrane filtration, pH value adjustment, ion exchange softening, advanced oxidation, biofilm biochemistry, membrane filter, nanofiltration, addition of lime milk to nanofiltration intercepted water to obtain calcium sulfate, and reflux of supernatant to the impure salt precipitation tank, nanofiltration permeate water is concentrated by reverse osmosis A and then concentrated by a brine concentrator, and the brine concentrator fresh water is concentrated by reverse osmosis B and refluxed to the brine concentrator, and the brine concentrator concentrated water enters the evaporation crystallization device, and then obtains sodium chloride and sodium nitrate respectively by heat separation and cold separation, and most of the crystallization mother liquor is refluxed for treatment, and a small part is dried for treatment; reverse osmosis produced water and distilled water are reused. The present invention recovers commercial calcium carbonate, magnesium hydroxide, calcium sulfate, sodium chloride, sodium nitrate salts and high-quality recycled water, with less solid waste discharge and low operating costs.

Description

Sewage recycling zero-emission device and method

Technical Field

The invention relates to the technical field of sewage treatment, in particular to a liquid zero discharge method for treating sewage to obtain reclaimed water and separating main salts in the water by crystallization.

Background

With the aggravation of human economic activities, water resources must become a bottleneck for economic development. Therefore, more and more cases need to regenerate sewage into regenerated water which can replace raw water, and in some cases, zero discharge of liquid needs to be realized.

The common regenerated water technology is that sewage after traditional biochemical treatment or sewage with lower organic matter pollution is subjected to flocculation precipitation, ultrafiltration and reverse osmosis treatment, and the main problem at present is that organic pollutant treatment is not deep before the sewage enters a membrane system, organic pollutant in water is still at a higher level, reverse osmosis cleaning is frequent, and reverse osmosis concentrated water cannot reach the emission standard.

The liquid zero-emission sewage treatment method generally comprises sewage chemical softening and flocculating settling, ultrafiltration, reverse osmosis, concentrated water reverse osmosis, brine concentration, evaporative crystallization and other devices, wherein the brine-brine concentration device comprises electrodialysis, a vapor mechanical compression evaporator, forward osmosis, membrane distillation, high-pressure reverse osmosis and the like. The main problem at present is that the reverse osmosis membrane needs frequent chemical cleaning due to the fact that organic pollutants are not deeply treated before entering the membrane system, and the evaporation and crystallization operation of concentrated water is difficult due to the fact that the organic pollutants in reverse osmosis concentrated water are too high in content due to the fact that the reverse osmosis membrane is not deeply treated before entering the membrane system, and a large amount of mixed salt and mixed salt mixture of the organic pollutants are obtained through evaporation and crystallization. Most of the mixed salt mixture is dissolved in water, and the improper treatment can cause environmental pollution again, so that the main mixture has high further treatment cost and even needs to be treated as dangerous waste.

The Chinese patent application (2015122599. X) mainly solves the problem of interference of organic matters in the sewage zero emission process, but does not recover indissolvable salt to ensure that the chemical sludge is too high, and obtains sodium sulfate through evaporation and crystallization to ensure that the evaporation and crystallization treatment capacity is increased, and the obtained sodium sulfate crystal containing crystal water has almost no recycling value and the treatment cost is increased.

The main cations in common sewage are sodium, calcium and magnesium, and the main anions are chloride, sulfate, nitrate and bicarbonate. Small amounts of potassium, fluorine, phosphate, etc. The sewage recycling zero-emission device and the treatment method aim to fully recycle and recycle the main cations and anions in the water and simultaneously reduce the total amount of solid wastes and the running cost.

Disclosure of Invention

The method solves the technical problems that reverse osmosis cleaning is frequent, reverse osmosis concentrated water cannot reach the discharge standard in the reclaimed water technology, reverse osmosis membranes need to be frequently and chemically cleaned in the liquid zero-discharge sewage treatment method, concentrated water is difficult to evaporate and crystallize to obtain a mixture of a large amount of mixed salt and organic pollutants, the whole system is difficult to stably operate for a long time, the salt recovery ratio is low, the chemical sludge amount is large, and the operation cost is high.

The invention discloses a sewage recycling zero-emission treatment device which sequentially comprises a flocculating agent adding device, a coagulant aid adding device, a mixed salt sedimentation tank, a soda adding device, a calcium carbonate sedimentation tank, a caustic soda adding device, a magnesium hydroxide sedimentation tank, an acid adding device, a cation exchanger, an oxidant adding device, an oxidation contactor, a biological membrane reactor, a blower, a membrane filter B, a nanofiltration membrane separator, a brine concentrator, an evaporation crystallization device, a heat separator, a cold separator and a mother liquor drier, and further comprises a cation exchanger regeneration wastewater reflux pipeline for refluxing the cation exchanger regeneration wastewater to the mixed salt sedimentation tank, a membrane filter B wastewater reflux pipeline for refluxing the membrane filter B wastewater of the mixed salt sedimentation tank, a calcium sulfate sedimentation tank for treating water retained by the nanofiltration membrane separator, a lime milk adding device for adding lime to the water retained by the nanofiltration membrane separator, a calcium sulfate reflux pipeline for refluxing the calcium sulfate filter separator to the mixed salt sedimentation tank, a reverse osmosis membrane to at least, a reverse osmosis membrane for refluxing part of the mixed salt sedimentation tank, and a plurality of reverse osmosis membrane recovery device for controlling the reverse osmosis membrane to at least one of the reverse osmosis membrane, and a plurality of reverse osmosis membrane recovery device for refluxing part of the mixed salt sedimentation tank, and a plurality of reverse osmosis membrane recovery device for producing a plurality of the reverse osmosis membrane.

And a membrane filter A waste water reflux pipeline for refluxing the membrane filter A waste water to the mixed salt sedimentation tank are also arranged between the magnesium hydroxide sedimentation tank and the cation exchanger.

And a reverse osmosis separator A is also arranged between the nanofiltration membrane separator and the brine concentrator, wherein concentrated water of the reverse osmosis separator A enters the brine concentrator, and fresh water of the reverse osmosis separator A is recycled water.

A dilution line for adding reuse water is also included between the cation exchanger and the oxidation contactor.

The brine concentrator is at least one of an electrodialysis device, a steam mechanical recompression evaporator, a multi-effect evaporator and a single-effect evaporator.

The evaporation crystallization device is at least one of a vapor mechanical recompression evaporation crystallizer, a multi-effect evaporation crystallizer and a single-effect crystallization evaporation crystallizer.

In order to achieve the aim, the invention discloses a sewage recycling zero-emission treatment method using the sewage recycling zero-emission treatment device, which comprises the steps that raw water is added with flocculant through a flocculant adding device and a coagulant aid adding device to add a small amount of indissolvable mixed salt containing phosphate and organic pollutants generated by the coagulant aid is precipitated in a mixed salt precipitation tank, and the indissolvable mixed salt forms solid waste; adding micro excessive sodium carbonate (sodium carbonate) into water produced in a mixed salt sedimentation tank through a sodium carbonate adding device, precipitating the generated calcium carbonate in the calcium carbonate sedimentation tank to obtain calcium carbonate, adding sodium hydroxide (sodium hydroxide) into water produced in the calcium carbonate sedimentation tank through the sodium carbonate adding device until the pH value is 11-12, precipitating the generated magnesium hydroxide in the magnesium hydroxide sedimentation tank to obtain magnesium hydroxide, adding acid into water produced in the magnesium hydroxide sedimentation tank through an acid adding device to adjust the pH value to 5-8, softening the water produced in the magnesium hydroxide sedimentation tank, introducing the water into a cation exchanger, refluxing regenerated wastewater of the cation exchanger into the mixed salt sedimentation tank through a regenerated wastewater reflux pipeline of the cation exchanger, adding an oxidant into the water produced in the cation exchanger through an oxidant adding device, introducing the water produced in the cation exchanger into an oxidation contactor, improving the biodegradability of organic pollutants through oxidation reaction, introducing water produced in the oxidation contactor into a biological membrane reactor, filtering the water produced in the biological membrane reactor through a membrane filter B, refluxing the wastewater produced by the membrane filter B through the membrane filter to the wastewater reflux pipeline of the membrane filter to the mixed salt sedimentation tank, introducing the water produced by the membrane filter B into a membrane separator, intercepting the water produced in the calcium sulfate emulsion sedimentation tank through the lime adding device, precipitating calcium sulfate in the calcium sulfate sedimentation tank, the method comprises the steps of enabling produced water in a calcium sulfate sedimentation tank to flow back to a nanofiltration membrane separator of a mixed salt sedimentation tank (1) through a backflow pipeline of the calcium sulfate sedimentation tank, enabling the permeate water to enter a brine concentrator, enabling fresh water in the brine concentrator to flow back to the brine concentrator through a backflow pipeline of the reverse osmosis B to enter water, enabling concentrated water produced by the brine concentrator to enter an evaporation crystallization device, enabling steam produced by the evaporation crystallization device to flow back to the mixed salt sedimentation tank through a heat recovery device, enabling sodium nitrate to be nearly saturated in hot mother liquor in the evaporation crystallization device, separating the hot mother liquor through a heat separator to obtain sodium chloride, enabling mother liquor separated by the heat separator to cool, enabling sodium nitrate to be separated through a cold separator to obtain sodium nitrate, enabling most of mother liquor separated through the cold separator to flow back to the evaporation crystallization device through a backflow pipeline of the mother liquor, enabling the mother liquor to be continuously circulated, enabling part of mother liquor to flow back to the mixed salt sedimentation tank through the mother liquor backflow pipeline of the mixed salt sedimentation tank when organic pollutants and other impurities affect purity of sodium chloride and sodium nitrate, enabling most of pollutants to be eliminated through the mixed salt sedimentation tank and the subsequent processes, enabling sodium nitrate and enabling the mother liquor to be further guaranteed to be dried to be a small in order to produce a dry mother liquor with little purity.

And a membrane filter A is further arranged between the magnesium hydroxide sedimentation tank and the acid adding device, water produced by the membrane filter A enters the cation exchanger after acid is added, and waste water of the membrane filter A flows back to the mixed salt sedimentation tank through a waste water backflow pipeline of the membrane filter A.

A reverse osmosis separator A is arranged between the nanofiltration membrane separator and the brine concentrator, fresh water of the reverse osmosis separator A is recycled water, and concentrated water of the reverse osmosis separator A enters the brine concentrator.

Repeating the adding of the oxidizing agent and the biochemical degradation reaction at least once.

And adding reuse water between the cation exchanger and the oxidation contactor through a dilution pipeline to adjust the salt content to be less than 2%.

The method has the advantages of degrading most organic pollutants, ensuring stable operation of a membrane system and an evaporator, recycling five salts of calcium carbonate, magnesium hydroxide, calcium sulfate, sodium chloride and sodium nitrate, recycling all common main ions in raw water, remarkably reducing solid wastes, obtaining high-quality reuse water, precipitating sulfate radicals, reducing evaporation of strong brine and reducing operation cost.

Drawings

FIG. 1 is a schematic flow chart of a sewage recycling treatment method.

The device comprises a mixed salt sedimentation tank 1, a calcium carbonate sedimentation tank 2, a magnesium hydroxide sedimentation tank 3, a membrane filter A4, a cation exchanger 5, an oxidation contactor 6, a biological membrane reactor 7, a membrane filter B8, a nanofiltration membrane separator 9, a calcium sulfate sedimentation tank 10, a reverse osmosis membrane separator A11, a brine concentrator 12, a reverse osmosis concentrator B13, a reverse osmosis concentrator 14, an evaporation crystallization device 15, a heat separator 16, a cold separator 17 and a mother liquor drier.

110. Membrane filter A wastewater return line, 120. Cation exchanger regeneration wastewater return line, 130, membrane filter B wastewater return line, 140, nanofiltration concentrate return line, 150, a water-producing return pipeline of a calcium sulfate sedimentation tank, 160, a reverse osmosis B concentrated water return pipeline, 170, a mother liquor return crystallizer pipeline and 180, a mother liquor return mixed salt sedimentation tank pipeline;

210. Flocculant adding device, 220, coagulant aid adding device, 230, soda adding device, 240, caustic soda adding device, 250, acid adding device, 260, oxidant adding device, 270, air blower, 280 and lime milk adding device;

300. Raw water 310, reclaimed water 320, calcium carbonate 330, magnesium hydroxide 340, calcium sulfate 350, sodium chloride 360, sodium nitrate;

410. insoluble salt, 420. Mother liquor drying product.

Detailed Description

As shown in figure 1, the sewage recycling zero-emission treatment device sequentially comprises a flocculating agent adding device (210), a coagulant aid adding device (220), a mixed salt sedimentation tank (1), a soda adding device (230), a calcium carbonate sedimentation tank (2), a caustic soda adding device (240), a magnesium hydroxide sedimentation tank (3), an acid adding device (250), a cation exchanger (5), an oxidizing agent adding device (260), an oxidation contactor (6), a biological membrane reactor (7) and a blower (270), a membrane filter B (8), a nanofiltration membrane separator (9), a brine concentrator (12), an evaporation crystallization device (14), a thermal separator (15), a cold separator (16) and a mother liquor desiccator (17), and further comprises a cation exchanger regenerated wastewater reflux pipeline (120) for refluxing the regenerated wastewater of the cation exchanger (5) to the mixed salt sedimentation tank (1), a membrane filter B wastewater reflux pipeline (130) for refluxing the wastewater of the membrane filter B (8) to the mixed salt sedimentation tank (1), a membrane filter B wastewater reflux pipeline (10) for treating the retention membrane separator (9), a concentrated sulfuric acid reflux pipeline (140) for refluxing the precipitated calcium sulfate reflux of the sedimentation tank (10), the device comprises a nanofiltration membrane separator (9), a lime milk adding device (280) for adding lime into trapped water of the nanofiltration membrane separator, a calcium sulfate sedimentation tank produced water backflow pipeline (150) for backflow of water produced by a calcium sulfate sedimentation tank (10) to a mixed salt sedimentation tank (1), a reverse osmosis B concentrated water backflow pipeline (160) for backflow of concentrated water of a reverse osmosis separator B (13) to a brine concentrator (12), a mother liquor backflow crystallizer pipeline (170) for backflow of part of crystallization mother liquor to an evaporator, a mother liquor backflow mixed salt sedimentation tank pipeline (180) for backflow of part of crystallization mother liquor to the mixed salt sedimentation tank (1), a plurality of sediment filter pressing drying devices, a plurality of membrane backwashing chemical cleaning devices, at least one cation exchanger regenerating device, a plurality of lifting pumps and an automatic control device.

In order to improve the regeneration period of the cation exchanger, a membrane filter A (4) and a membrane filter A waste water reflux pipeline (110) for refluxing the waste water of the membrane filter A (4) to the mixed salt sedimentation tank (1) are also arranged between the magnesium hydroxide sedimentation tank (3) and the cation exchanger (5).

The membrane filter A (4) is at least one of a cross-flow internal pressure tubular membrane filter and a cross-flow internal pressure capillary membrane filter. The membrane filter B is one of various ultrafiltration or microfiltration.

When the salt content of the raw water is less than 2%, a reverse osmosis separator A (11) is arranged between the nanofiltration membrane separator (9) and the brine concentrator (12), the concentrated water of the reverse osmosis separator A (11) enters the brine concentrator (12), and the fresh water is recycled water (310).

When the salt content of the raw water is more than 2%, the method is characterized in that a dilution pipeline (190) for adding reuse water (310) is arranged between the cation exchanger (5) and the oxidation contactor (6), and the salt content is adjusted to be between 1 and 2 percent so as to be beneficial to the reaction efficiency of the subsequent biological membrane reactor (7).

The oxidant is ozone, and the oxidant adding device (260) is an ozone generator, an ozone adding facility and an ozone catalytic bed.

The oxidant is hydrogen peroxide, and the oxidant adding device (260) is a hydrogen peroxide metering and adding facility.

The brine concentrator (12) is at least one of an Electrodialysis (ED) unit, a steam mechanical recompression evaporator, a multiple effect evaporator, a single effect evaporator.

The mother liquor dryer is one of a spray dryer and an evaporation pond.

The sewage recycling zero-emission treatment method using the sewage recycling zero-emission treatment device comprises the steps of adding flocculant and coagulant aid additive by raw water (300) through a flocculant adding device (210), adding a small amount of indissolvable mixed salt (410) containing phosphate and organic pollutants generated by coagulant aid by the coagulant aid adding device (220) to precipitate in a mixed salt precipitation tank (1), forming solid waste by indissolvable mixed salt (410), adding micro excessive sodium carbonate (sodium carbonate) into produced water of the mixed salt precipitation tank (1) through a soda adding device (230), precipitating produced calcium carbonate (320) in a calcium carbonate precipitation tank (2) to obtain calcium carbonate (320), adding caustic soda (sodium hydroxide) to pH=11-12 by the calcium carbonate precipitation tank (2) through a caustic soda adding device (240), precipitating produced magnesium hydroxide (330) in a magnesium hydroxide precipitation tank (3), adding acid to adjust pH value to 5-8 by the produced water of the magnesium hydroxide precipitation tank (3), softening by a cation exchanger (5), regenerating waste water by a cation exchanger (5) through a cation exchanger (120), oxidizing waste water by a waste water of the cation exchanger (6) to enter a waste water oxidizing agent in a reflux device (260), the biodegradability of organic pollutants is improved through oxidation reaction, water discharged from an oxidation contactor (6) enters a biological membrane reactor (7) to be subjected to biochemical degradation reaction of the organic pollutants, water produced by the biological membrane reactor (7) is filtered by a membrane filter B, wastewater produced by the filtration of the membrane filter B is returned to a salt water sedimentation tank (1) through a wastewater return pipeline (130) of the membrane filter B, water produced by the membrane filter B enters a nanofiltration membrane separator (9), water trapped by the nanofiltration membrane separator (9) is added with lime milk through a lime milk adding device (280), calcium sulfate (340) produced is precipitated in a calcium sulfate sedimentation tank (10) to obtain calcium sulfate (340), water produced by the calcium sulfate sedimentation tank (10) is returned to the salt water sedimentation tank (1) through a return pipeline (150), water produced by the nanofiltration membrane separator (9) is transmitted to a salt water concentrator (12), fresh water produced by the salt water concentrator (12) is processed through a reverse osmosis B (13) to obtain reclaimed water (310), the reverse osmosis B (13) is returned to the salt water concentrator (12) through a reverse osmosis B concentrated water return pipeline (160), the brine water produced by the reverse osmosis B (12) is returned to a crystallization water concentrator (14) is heated to obtain water concentrate (14) which is recovered and enters a crystallization water recovery device (14) to obtain heat recovery device, and the heat recovery device is nearly saturated with water vapor (14), the method comprises the steps of separating hot mother liquor through a hot separator (15) to obtain sodium chloride (350), cooling the mother liquor separated by the hot separator (15), initiating a sodium nitrate crystallization process, separating the mother liquor through a cold separator (16) to obtain sodium nitrate (360), refluxing most of the mother liquor separated by the cold separator (16) to an evaporation crystallization device (14) through a mother liquor reflux crystallizer pipeline (170) for continuous evaporation crystallization, circulating in such a way, refluxing part of the mother liquor to a mixed salt precipitation tank (1) through a mother liquor reflux mixed salt precipitation tank pipeline (180) when organic pollutants and other impurities of the mother liquor influence the purity of the sodium chloride (350) and the sodium nitrate (360), and eliminating most of pollutants in the mother liquor through the mixed salt precipitation tank (1) and the subsequent processes, and drying a small part of the mother liquor through a mother liquor dryer (17) to further ensure the purity of the sodium chloride (350) and the sodium nitrate (360), so as to generate a dried product (420).

In order to improve the regeneration cycle of the cation exchanger, a membrane filter A (4) is further arranged between the magnesium hydroxide sedimentation tank (3) and the acid adding device (250), the produced water of the membrane filter A (4) enters the cation exchanger (5) after being added with acid, and the wastewater of the membrane filter A (4) flows back to the mixed salt sedimentation tank (1) through a wastewater backflow pipeline (110) of the membrane filter A.

When the salt content of the raw water is less than 2%, a reverse osmosis separator A (11) is arranged between the nanofiltration membrane separator (9) and the brine concentrator (12), the fresh water of the reverse osmosis separator A (11) is recycled water (310), and the concentrated water of the reverse osmosis separator A (11) enters the brine concentrator (12).

When the content of refractory organic pollutants in raw water is high, the oxidant and the biochemical degradation reaction are repeatedly added at least once.

When the salt content of the raw water is more than 2%, the reuse water (310) is added between the cation exchanger (5) and the oxidation contactor through the dilution pipeline (190), and the salt content is regulated to be less than 2% so as to be beneficial to the reaction efficiency of the subsequent biological membrane reactor (7).

Claims

1. A wastewater resource recovery zero-discharge treatment device, characterized in that it comprises, in sequence, a flocculant addition device (210), a coagulant aid addition device (220), a salt precipitation tank (1), a soda ash addition device (230), a calcium carbonate precipitation tank (2), a caustic soda addition device (240), a magnesium hydroxide precipitation tank (3), an acid addition device (250), a cation exchanger (5), an oxidant addition device (260), an oxidation contactor (6), and a biofilm reactor. The invention also comprises a cation exchanger regeneration wastewater return pipe (120) for returning the regeneration wastewater of the cation exchanger (5) to the mixed salt precipitation tank (1), a membrane filter B (8), a nanofiltration membrane separator (9), a salt water concentrator (12), an evaporation crystallization device (14), a hot separator (15), a cold separator (16), and a mother liquor dryer (17); and also comprises a cation exchanger regeneration wastewater return pipe (120) for returning the regeneration wastewater of the cation exchanger (5) to the mixed salt precipitation tank (1), a membrane filter B wastewater return pipe (120) for returning the wastewater of the membrane filter B (8) to the mixed salt precipitation tank (1), and a membrane filter B wastewater return pipe (121) for returning the wastewater of the membrane filter B (8) to the mixed salt precipitation tank (1). a water return pipe (130), a calcium sulfate precipitation tank (10) for treating the retained water of the nanofiltration membrane separator (9), a nanofiltration concentrated water return pipe (140) for returning the retained water of the nanofiltration membrane separator (9) to the calcium sulfate precipitation tank (10), a lime milk adding device (280) for adding lime to the retained water of the nanofiltration membrane separator (9); a calcium sulfate precipitation tank produced water return pipe (150) for returning the produced water of the calcium sulfate precipitation tank (10) to the miscellaneous salt precipitation tank (1), and a nanofiltration concentrated water return pipe (140) for returning the retained water of the nanofiltration membrane separator (9) to the calcium sulfate precipitation tank (10); and a lime milk adding device (280) for adding lime to the retained water of the nanofiltration membrane separator (9). The reverse osmosis separator B (13) includes a reverse osmosis B concentrated water return pipe (160) for returning concentrated water to the salt water concentrator (12), a mother liquor return crystallizer pipe (170) for returning part of the crystallized mother liquor to the evaporator, and a mother liquor return mixed salt precipitation tank pipe (180) for returning part of the crystallized mother liquor to the mixed salt precipitation tank (1); and also includes a plurality of sediment filter press drying devices, a plurality of membrane backwashing and chemical cleaning devices, at least one cation exchanger regeneration device, a plurality of lifting pumps and an automatic control device.

2. The wastewater resource zero-discharge treatment device according to claim 1 is characterized in that it also includes a membrane filter A (4) and a membrane filter A wastewater return pipe (110) for returning the wastewater of the membrane filter A (4) to the mixed salt precipitation tank (1) between the magnesium hydroxide precipitation tank (3) and the cation exchanger (5).

3. The wastewater resource recovery zero-discharge treatment device according to claim 1 is characterized in that a reverse osmosis separator A (11) is provided between the nanofiltration membrane separator (9) and the brine concentrator (12), and the concentrated water of the reverse osmosis separator A (11) enters the brine concentrator (12), and the fresh water thereof is recycled water (310).

4. The wastewater resource recovery zero-discharge treatment device according to claim 1 is characterized in that it also includes a dilution pipeline (190) for adding recycled water (310) between the cation exchanger (5) and the oxidation contactor (6).

5. The wastewater resource zero-discharge treatment device according to claim 1 is characterized in that the brine concentrator (12) is at least one of an electrodialysis (ED) device, a steam mechanical recompression evaporator, a multiple-effect evaporator, and a single-effect evaporator.

6. The wastewater resource zero-discharge treatment device according to claim 1 is characterized in that the evaporation crystallization device (14) is at least one of a steam mechanical recompression evaporation crystallizer, a multi-effect evaporation crystallizer, and a single-effect crystallization evaporation crystallizer.

7. A method for treating wastewater as a resource with zero discharge, characterized in that the wastewater as a resource with zero discharge treatment device according to claim 1, 4, 5 or 6 is used, comprising: adding flocculant to raw water (300) through a flocculant adding device (210) and adding flocculant aid to raw water (220); a small amount of insoluble salts (410) containing phosphate and organic pollutants are precipitated in a salt precipitation tank (1), and the insoluble salts (410) form solid waste; adding a small amount of soda ash (sodium carbonate) to the water produced by the salt precipitation tank (1) through a soda ash adding device (230), and the generated calcium carbonate (320) is precipitated in a calcium carbonate precipitation tank (2) to obtain calcium carbonate (320); adding caustic soda (sodium hydroxide) to the water produced by the calcium carbonate precipitation tank (2) to pH = 11-12 through a caustic soda adding device (240), and the generated magnesium hydroxide (330) is precipitated in a magnesium hydroxide precipitation tank (3). Precipitation to obtain magnesium hydroxide (330); the water produced by the magnesium hydroxide precipitation tank (3) is acidified by an acid adding device (250) to adjust the pH value to 5-8, and enters the cation exchanger (5) for softening; the regenerated wastewater of the cation exchanger (5) is returned to the salt precipitation tank (1) through the cation exchanger regeneration wastewater return pipe (120); the oxidant is added to the water produced by the cation exchanger (5) through the oxidant adding device (260), and enters the oxidation contactor (6), and the biodegradability of organic pollutants is improved through oxidation reaction; the effluent of the oxidation contactor (6) enters the biofilm reactor (7), and the biochemical degradation reaction of organic pollutants occurs; the water produced by the biofilm reactor (7) is filtered through the membrane filter B, and the wastewater generated by the filtration of the membrane filter B is returned to the salt precipitation tank (1) through the membrane filter B wastewater return pipe (130); the water produced by the membrane filter B enters the nanofiltration membrane separator (9), and the nanofiltration The retained water of the membrane separator (9) is added with lime milk through a lime milk adding device (280), and the generated calcium sulfate (340) is precipitated in a calcium sulfate precipitation tank (10) to obtain calcium sulfate (340). The produced water of the calcium sulfate precipitation tank (10) is refluxed to the miscellaneous salt precipitation tank (1) through a calcium sulfate precipitation tank reflux pipe (150), and the permeated water of the nanofiltration membrane separator (9) enters a salt water concentrator (12); the fresh water of the salt water concentrator (12) is treated by reverse osmosis B (13) to obtain recycled water (310), and the concentrated water of the reverse osmosis B (13) is refluxed to the salt water concentrator (12) through a reverse osmosis B concentrated water reflux pipe (160); the concentrated water generated by the salt water concentrator (12) enters an evaporation crystallization device (14), and the steam generated by the evaporation crystallization device (14) is passed through a heat recovery device to obtain recycled water (310), and the evaporation concentration is controlled so that sodium nitrate is absorbed in the hot mother liquor in the evaporation crystallization device (14). When the mother liquor is close to saturation, the hot mother liquor is separated by a hot separator (15) to obtain sodium chloride (350). The mother liquor separated by the hot separator (15) is cooled to initiate a sodium nitrate crystallization process, and is separated by a cold separator (16) to obtain sodium nitrate (360). Most of the mother liquor separated by the cold separator (16) is refluxed to the evaporation crystallization device (14) through the mother liquor reflux crystallizer pipeline (170) to continue evaporation crystallization, and the cycle is repeated. When organic pollutants and other impurities in the mother liquor affect the purity of sodium chloride (350) and sodium nitrate (360), part of the mother liquor is refluxed to the miscellaneous salt precipitation tank (1) through the mother liquor reflux miscellaneous salt precipitation tank pipeline (180), and most of the pollutants therein are eliminated by the miscellaneous salt precipitation tank (1) and its subsequent processes. In order to further ensure the purity of sodium chloride (350) and sodium nitrate (360), a small part of the mother liquor is dried by a mother liquor dryer (17) to produce a mother liquor dried product (420).

8. The method for treating wastewater as a resource with zero discharge according to claim 7 is characterized in that a membrane filter A (4) is further provided between the magnesium hydroxide precipitation tank (3) and the acid adding device (250), the water produced by the membrane filter A (4) enters the cation exchanger (5) after acid addition, and the wastewater of the membrane filter A (4) is returned to the miscellaneous salt precipitation tank (1) through the wastewater return pipe (110) of the membrane filter A.

9. The method for treating wastewater as a resource with zero discharge according to claim 7 is characterized in that a reverse osmosis separator A (11) is provided between the nanofiltration membrane separator (9) and the brine concentrator (12), the fresh water of the reverse osmosis separator A (11) is recycled water (310), and the concentrated water of the reverse osmosis separator A (11) enters the brine concentrator (12).

10. The method for treating wastewater as a resource with zero discharge according to claim 7, 8 or 9, characterized in that the addition of oxidant and the biochemical degradation reaction are repeated at least once.

11. The method for treating wastewater as a resource with zero discharge according to claim 7, 8, 9 or 10, characterized in that recycled water (310) is added between the cation exchanger (5) and the oxidation contactor through a dilution line (190) to adjust the salt content to less than 2%.