CN108623104A - A kind of high-salinity wastewater zero-emission processing method and processing device based on NF membrane allotment - Google Patents

A kind of high-salinity wastewater zero-emission processing method and processing device based on NF membrane allotment Download PDF

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CN108623104A
CN108623104A CN201810778712.4A CN201810778712A CN108623104A CN 108623104 A CN108623104 A CN 108623104A CN 201810778712 A CN201810778712 A CN 201810778712A CN 108623104 A CN108623104 A CN 108623104A
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concentration
membrane
crystal
water
nacl
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邢卫红
张荟钦
杨刚
杨积衡
李卫星
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Nanjing University of Science and Technology
Nanjing Tech University
Jiangsu Jiuwu Hi Tech Co Ltd
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Nanjing University of Science and Technology
Jiangsu Jiuwu Hi Tech Co Ltd
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    • CCHEMISTRY; METALLURGY
    • C01INORGANIC CHEMISTRY
    • C01DCOMPOUNDS OF ALKALI METALS, i.e. LITHIUM, SODIUM, POTASSIUM, RUBIDIUM, CAESIUM, OR FRANCIUM
    • C01D3/00Halides of sodium, potassium or alkali metals in general
    • C01D3/04Chlorides
    • CCHEMISTRY; METALLURGY
    • C01INORGANIC CHEMISTRY
    • C01DCOMPOUNDS OF ALKALI METALS, i.e. LITHIUM, SODIUM, POTASSIUM, RUBIDIUM, CAESIUM, OR FRANCIUM
    • C01D3/00Halides of sodium, potassium or alkali metals in general
    • C01D3/14Purification
    • CCHEMISTRY; METALLURGY
    • C01INORGANIC CHEMISTRY
    • C01DCOMPOUNDS OF ALKALI METALS, i.e. LITHIUM, SODIUM, POTASSIUM, RUBIDIUM, CAESIUM, OR FRANCIUM
    • C01D5/00Sulfates or sulfites of sodium, potassium or alkali metals in general
    • C01D5/16Purification
    • CCHEMISTRY; METALLURGY
    • C02TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02FTREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F9/00Multistage treatment of water, waste water, or sewage
    • CCHEMISTRY; METALLURGY
    • C02TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02FTREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00Treatment of water, waste water, or sewage
    • C02F1/001Processes for the treatment of water whereby the filtration technique is of importance
    • CCHEMISTRY; METALLURGY
    • C02TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02FTREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00Treatment of water, waste water, or sewage
    • C02F1/02Treatment of water, waste water, or sewage by heating
    • C02F1/04Treatment of water, waste water, or sewage by heating by distillation or evaporation
    • C02F1/048Purification of waste water by evaporation
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    • C02TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02FTREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00Treatment of water, waste water, or sewage
    • C02F1/30Treatment of water, waste water, or sewage by irradiation
    • C02F1/302Treatment of water, waste water, or sewage by irradiation with microwaves
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    • C02TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02FTREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00Treatment of water, waste water, or sewage
    • C02F1/42Treatment of water, waste water, or sewage by ion-exchange
    • CCHEMISTRY; METALLURGY
    • C02TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02FTREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00Treatment of water, waste water, or sewage
    • C02F1/44Treatment of water, waste water, or sewage by dialysis, osmosis or reverse osmosis
    • CCHEMISTRY; METALLURGY
    • C02TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02FTREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00Treatment of water, waste water, or sewage
    • C02F1/44Treatment of water, waste water, or sewage by dialysis, osmosis or reverse osmosis
    • C02F1/441Treatment of water, waste water, or sewage by dialysis, osmosis or reverse osmosis by reverse osmosis
    • CCHEMISTRY; METALLURGY
    • C02TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02FTREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00Treatment of water, waste water, or sewage
    • C02F1/44Treatment of water, waste water, or sewage by dialysis, osmosis or reverse osmosis
    • C02F1/442Treatment of water, waste water, or sewage by dialysis, osmosis or reverse osmosis by nanofiltration
    • CCHEMISTRY; METALLURGY
    • C02TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02FTREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00Treatment of water, waste water, or sewage
    • C02F1/44Treatment of water, waste water, or sewage by dialysis, osmosis or reverse osmosis
    • C02F1/444Treatment of water, waste water, or sewage by dialysis, osmosis or reverse osmosis by ultrafiltration or microfiltration
    • CCHEMISTRY; METALLURGY
    • C02TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02FTREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00Treatment of water, waste water, or sewage
    • C02F1/46Treatment of water, waste water, or sewage by electrochemical methods
    • C02F1/469Treatment of water, waste water, or sewage by electrochemical methods by electrochemical separation, e.g. by electro-osmosis, electrodialysis, electrophoresis
    • C02F1/4693Treatment of water, waste water, or sewage by electrochemical methods by electrochemical separation, e.g. by electro-osmosis, electrodialysis, electrophoresis electrodialysis
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    • C02TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02FTREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00Treatment of water, waste water, or sewage
    • C02F1/72Treatment of water, waste water, or sewage by oxidation
    • C02F1/722Oxidation by peroxides
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    • C02TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02FTREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00Treatment of water, waste water, or sewage
    • C02F1/72Treatment of water, waste water, or sewage by oxidation
    • C02F1/725Treatment of water, waste water, or sewage by oxidation by catalytic oxidation
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    • C02TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02FTREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00Treatment of water, waste water, or sewage
    • C02F1/72Treatment of water, waste water, or sewage by oxidation
    • C02F1/78Treatment of water, waste water, or sewage by oxidation with ozone
    • CCHEMISTRY; METALLURGY
    • C02TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02FTREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00Treatment of water, waste water, or sewage
    • C02F2001/007Processes including a sedimentation step
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    • C02TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02FTREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F2103/00Nature of the water, waste water, sewage or sludge to be treated
    • C02F2103/26Nature of the water, waste water, sewage or sludge to be treated from the processing of plants or parts thereof
    • C02F2103/28Nature of the water, waste water, sewage or sludge to be treated from the processing of plants or parts thereof from the paper or cellulose industry
    • CCHEMISTRY; METALLURGY
    • C02TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02FTREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F2301/00General aspects of water treatment
    • C02F2301/08Multistage treatments, e.g. repetition of the same process step under different conditions
    • CCHEMISTRY; METALLURGY
    • C02TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02FTREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F2305/00Use of specific compounds during water treatment
    • C02F2305/02Specific form of oxidant
    • C02F2305/026Fenton's reagent
    • CCHEMISTRY; METALLURGY
    • C02TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02FTREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F3/00Biological treatment of water, waste water, or sewage
    • CCHEMISTRY; METALLURGY
    • C02TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02FTREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F5/00Softening water; Preventing scale; Adding scale preventatives or scale removers to water, e.g. adding sequestering agents

Abstract

The present invention relates to a kind of high-salinity wastewater zero-emission processing method and processing devices based on NF membrane mixing system.The technique key step is as follows:By the preprocessed system removal of impurities of high-salt wastewater, salt concentrate, after softening, concentrated water after softening enters nanofiltration mixing system, allocate the concentration of a divalent salts, make the concentration ratio of a divalent salts of nanofiltration concentrated water between 0.01~0.1, nanofiltration mixing system concentrated water enters the acquisition of sulfate crystal system and meets Nacl requirement divalent product salt and sodium chloride-containing mother liquor, nanofiltration mixing system penetrating fluid enters sodium chloride crystal system after upgrading system again and obtains sodium chloride salt product and sulfur acid mother liquid of sodium, sodium chloride crystalline mother solution enters after removal of impurities in sulfate crystal system, sulfate crystal mother liquor enters sodium chloride crystal system after removal of impurities, it realizes wastewater zero discharge and stabilizes the fluctuation of salinity in crystal system.

Description

A kind of high-salinity wastewater zero-emission processing method and processing device based on NF membrane allotment
Technical field
The present invention relates to a kind of high-salinity wastewater zero-emission processing method and processing devices based on NF membrane allotment, belong to water process Technical field.
Background technology
The waste water of the discharges such as paper industry, printing and dyeing industry, chemical engineering industry, pharmaceuticals industry contains certain density inorganic Salt, all referred in wastewater zero discharge processing procedure how the technique for detaching inorganic salts from waste water.For brine waste zero Discharge reduces COD and SS using advanced oxidation pretreatment, is concentrated on this basis using reverse osmosis membrane, with cycles of concentration Rising, the hardness in waste water also gradually rises." two alkaline process " or " resin tenderizer " removing can be used in waste water after concentrated Hardness in waste water.Waste water through removing hardness is tied after the techniques such as reverse osmosis or electrodialysis further concentration using evaporation Brilliant technique obtains Nacl.The clear water that film concentration process generates is used for each production workshop section according to water quality difference.Such brine waste Technique of zero discharge Chinese invention patent(CN103508602A, CN104071808A)It has been reported that but not related in these patents And how to realize the separation problem of a divalent salts, obtained carnallite is difficult to recycling.
Brine waste zero emission technique is divided into cycle pretreatment, cycle minimizing and zero by Chinese patent CN105540972A Three parts of exhaust unit.The separation of sal prunella is realized during evaporative crystallization technique.The technique is mainly in brine waste Monovalent salt and the larger system of divalent salts concentration difference, can be obtained by controlling the operating condition of crystallization processes technical grade monovalent salt and Divalent salts, due to industrial wastewater complicated component and monovalent salt is difficult to meet the separation of sal prunella with divalent salts concentration difference, this is specially The restricted application of profit.
Chinese patent CN104370405A carries out a point salt treatment using nanofiltration to high concentration brine, by nanofiltration fresh water into It is used for regenerating softener after row concentration.Nanofiltration concentrated water obtains solid content for evaporative crystallization, can get the divalent salts production of high-purity Object, but the fresh water of nanofiltration does not do concentrate and obtains monovalence product salt, the outer row for causing this part brine waste or the interior enrichment of system, it should Patent addresses only the problem of part salt utilizes.
Invention content
The technical problem to be solved by the present invention is to:For the concentration ratio of sodium chloride in brine waste and sodium sulphate discomfort Close using method for crystallising separation the problem of, using nanofiltration technique in brine waste monovalent salt and divalent salinity adjust Section so that waste water of the NF membrane after proportion adjustment can further be concentrated using reverse osmosis or electrodialysis process, concentration Brine waste can obtain sodium chloride and sodium sulphate Nacl by corresponding crystallization processes respectively.
The first aspect of the invention:
A kind of high-salinity wastewater zero-emission method, includes the following steps:
1st step cleans the preprocessed system of brine waste;
2nd step carries out concentration to the waste water that the 1st step obtains;
3rd step carries out sofening treatment to the waste water that the 2nd step obtains;
4th step is handled the waste water that the 3rd step obtains using nanofiltration membrane, adjusts the NaCl and Na in waste water2SO4Concentration ratio Example;
The concentrated water of 5th step, NF membrane is sent into Na2SO4Crystal system obtains Na by Crystallization Separation2SO4Nacl and first Mother liquor;The fresh water of NF membrane is concentrated and then is sent into NaCl crystal system, and NaCl Nacls are obtained by Crystallization Separation And second mother liquor;
6th step, the first mother liquor, which is sent into NaCl crystal systems, carries out crystallization treatment, and the second mother liquor is sent into Na2SO4Crystal system into Row crystallization treatment.
In one embodiment, pretreatment system is discharged COD between 10~200mg/L in the 1st step, SS 3~ 50mg/L。
In one embodiment, the pretreatment in the 1st step refers to pre-filtering, biofilter, precipitation, oxidation or ultrafiltration In one or more combinations.
In one embodiment, pre-filtering is one or more in sand filtration, multi-medium filtering or activated carbon filtering Combination.
In one embodiment, oxidation is using one in ozonation technology, Fenton oxidation technology or microwave oxidation Kind or a variety of combinations;Biofilter refers to activated carbon bio-filter.
In one embodiment, concentration makes in waste water TDS in 20~60g/L;Concentration process is dense using NF membrane One or more process combinations in contracting, reverse osmosis concentration or electrodialysis concentration.
In one embodiment, melded system goes out the water hardness between 20~200mg/L in the 3rd step;Softening process can Using one or more process combinations in film softening, medicament softening or ion exchange resin softening.
In one embodiment, in the 4th step, the NaCl in NF membrane concentrated water and Na2SO4The concentration mass ratio of concentration 0.01~0.07:1;Na in the concentrated water of NF membrane2SO4Mass concentration 8~15%.
In one embodiment, in the 5th step, the fresh water of NF membrane carry out concentration be using high pressure reverse osmosis membrane technique, The combination of one or more of DTRO techniques, electrodialysis process, MVR evaporation technologies or multiple-effect evaporation technique;NF membrane fresh water NaCl mass concentrations are between 10~20% after concentration.
In one embodiment, the first mother liquor is re-fed into NaCl crystal systems after concentration and carries out at crystallization Reason, the second mother liquor are re-fed into Na after crossing concentration2SO4Crystal system carries out crystallization treatment.
The second aspect of the invention:
A kind of high-salinity wastewater zero-emission processing unit, including:
Pretreatment system, for carrying out pretreatment removal of impurities to high-salt wastewater;
Concentration systems are connected to pretreatment system, and the waste water for being obtained to pretreatment system carries out concentration;
Melded system is connected to concentration systems, for carrying out sofening treatment to the waste water after concentration;
NF membrane is connected to melded system, the separation for carrying out a divalent salts to the production water after sofening treatment;
Sulfate crystal system is connected to the dope side of NF membrane, for nanofiltration dope crystallization treatment, obtaining Na2SO4
Sodium chloride crystal system is connected to the light liquid side of NF membrane, for the light liquid crystallization treatment of nanofiltration, obtaining NaCl.
In one embodiment, the mother liquor outlet of sulfate crystal system is connected to sodium chloride crystal system, sodium chloride The mother liquor outlet of crystal system is connected to sulfate crystal system.
In one embodiment, the pretreatment system includes pre-filtrating equipment, biofilter, settler, oxygen Makeup set or ultrafiltration apparatus in one or more combinations.
In one embodiment, pre-filtrating equipment is sand filtering device, multi-medium filtering device or activated carbon filtering dress One or more combinations in setting.
In one embodiment, bacteria filter device is activated carbon bio-filter device.
In one embodiment, oxidation unit is ozone-oxidizing device, Fenton oxidation device or microwave oxidation unit In one or more combinations.
In one embodiment, the concentration systems include nanofiltration film condensing device, reverse osmosis concentrated compression apparatus or One or more combinations in electrodialysis enrichment facility.
In one embodiment, the light liquid side of NF membrane is connect by enrichment facility with sodium chloride crystal system.
In one embodiment, enrichment facility is selected from high pressure reverse osmosis membrane apparatus, DTRO devices, electrodialysis plant, MVR The combination of one or more of vaporising device or multi-effect evaporating device.
Advantageous effect
The targeted brine waste wide adaptability of the present invention adjusts monovalent salt by controlling nanofiltration cycles of concentration and rejection With the ratio of divalent salts, meet follow-up NaCl and Na2SO4The requirement for crystallizing reuse technology respectively, realizes wastewater zero discharge, and obtain The monovalent salt and divalent product salt for obtaining the high technical grade of purity, have the advantages that energy-efficient emission reduction.
The present invention main innovation point be by NF membrane be used for in high-salt wastewater monovalent salt and divalent salts ratio into Row is adjusted, and meets NaCl and Na2SO4The requirement crystallized respectively recycles the mother liquor of crystallization process, reduces mother liquor amount, Improve the efficiency that sal prunella joint process salt utilizes.The monovalent salt of high-purity is finally obtained while realizing brine waste zero emission With divalent salts, the recycling of water and inorganic salts is realized.
In addition, due in NaCl and Na2SO4During crystallizing respectively, the NaCl and Na in feed liquid are crystallized2SO4Concentration It is bigger than differing, more it is conducive to the crystal salt that crystallization process forms high-purity.And since the salinity in high-salt wastewater can be sent out Raw periodically fluctuation, is easy to cause the fluctuation for obtaining the generating period of the concentration in light liquid and dope in nanofiltration process, influences To crystallization process.Therefore, by being returned again to later to upper level using the further concentrate of reverse osmosis membrane to the mother liquor after crystallization Crystal system can effectively make NaCl and Na2SO4Concentration ratio fluctuation numerical value reduce, it is suppressed that the shakiness in crystallization process Qualitatively occur.
Description of the drawings
Fig. 1 is method overall flow figure provided by the invention.
Fig. 2 is installation drawing provided by the invention.
Wherein, 1, pretreatment system;2, concentration systems;3, melded system;4, NF membrane;5, sulfate crystal system;6、 Sodium chloride crystal system.
Specific implementation mode
Below by specific implementation mode, invention is further described in detail.But those skilled in the art will manage Solution, the following example is merely to illustrate the present invention, and should not be taken as limiting the scope of the invention.Specific skill is not specified in embodiment Art or condition person carry out according to technology or condition described in document in the art or according to product description.Examination used Production firm person is not specified in agent or instrument, and being can be with conventional products that are commercially available.
The value expressed using range format should be interpreted as not only in a flexible way including clearly enumerating as range The numerical value of limit value, but also include all single numbers or the subinterval covered in the range, like each numerical value and sub-district Between be expressly recited out.For example, the concentration range of " about 0.1% to about 5% " should be understood as including not only clearly enumerating The concentration of about 0.1% to about 5% further includes the single concentration in how(Such as, 1%, 2%, 3% and 4%)The subinterval and(Example Such as, 0.1% to 0.5%, 1% to 2.2%, 3.3% to 4.4%).
" one embodiment " for addressing in the present specification, " another embodiment ", " embodiment " etc., refer to In conjunction with the specific features of embodiment description, structure or it is included at least one embodiment generally described herein. It is not centainly to refer to the same embodiment that statement of the same race, which occur, in multiple places in the description.Furthermore, it is understood that in conjunction with any When embodiment describes a specific features, structure or feature, what is advocated is that this spy is realized in conjunction with other embodiment Sign, structure or feature are also fallen in the application scope of the claimed.
It should be understood that when an element is mentioned with another element " connection ", it can be direct with other elements It is connected or is indirectly connected with other elements, and inserted with element between them.Unless there are clearly opposite explanation, otherwise term It includes listed element that " comprising " and " having ", which is interpreted as statement, and non-excluded arbitrary other elements.
Word "include", "comprise" used herein, " having " or its any other variant are intended to cover non-exclusionism Including.E.g., including technique, method, article or the equipment for listing element are not necessarily limited by those elements, but may include Other are not explicitly listed or belong to this technique, method, article or the intrinsic element of equipment.
The present invention relates to a kind of technique of high-salinity wastewater zero-emission, required high-salt wastewater to be processed be primarily referred to as containing NaCl、Na2SO4, the substances such as COD waste water, wherein also containing some Ca2+、Mg2+Hardness etc..High-salt wastewater mainly can be with Middle water that middle water and tail water in paper-making process after treatment, which can also be coal chemical industrial waste water, to be obtained by processing and Tail water etc..Some typical water quality situations are:COD is in COD in 10~200mg/L, 50~1000 mg/L of total hardness(With CaCO3 Meter), TDS is in 1000~20000 mg/L, and total suspended matter SS is in 3~50mg/L, and NaCl concentration is in 200~5000mg/L, Na2SO4 200~5000mg/L of concentration range.Method of the invention is particularly suitable for NaCl and Na2SO4Concentration proportion can not be direct The case where the two is detached by way of evaporative crystallization;Such as NaCl and Na2SO4Mass concentration ratio 10:1~1:10 this A range can also be 5:1~1:5, can also be 2:1~1:2.
Main technological process is as follows:
Step 1:By the preprocessed system removal of impurities of high-salt wastewater, pretreatment system water outlet;
Step 2:Enter salt upgrading system after removal of impurities, makes in waste water that for TDS in 20~60g/L, reverse osmosis freshwater enters reuse water system System;
Step 3, salt upgrading system concentrated water enter melded system, and melded system goes out the water hardness between 50~200mg/L;
Concentrated water after step 4, softening enters nanofiltration mixing system, allocates the concentration of a divalent salts, makes a divalent of nanofiltration concentrated water The concentration ratio of salt is between 0.01~0.1;
Step 5, nanofiltration mixing system concentrated water enter Na2SO4Crystal system acquisition meets Nacl requirement Na2SO4Nacl and mother Liquid;
Step 6, nanofiltration mixing system penetrating fluid after upgrading system again enter NaCl crystal systems obtain NaCl Nacls and Mother liquor;
Step 7, Na2SO4The condensed water of crystal system and NaCl crystal systems enters reuse water system Na2SO4Crystal system discharges Mother liquor enters after removal of impurities in NaCl crystal systems, and NaCl crystal systems discharge mother liquor and enter Na after removal of impurities2SO4Crystal system In, realize wastewater zero discharge;
Step 8, each system purified water meet different reuse requirements after the allotment of reuse water system, realize quality classification water supply.
Further, pretreatment unit described in step 1 is mainly to carry out pre- removal of impurities processing to water quality using some conventional Process, main purpose is to get rid of the impurity that removal is easier in waste water, and mitigate subsequent membrane process, evaporation process etc. Load, and water quality can be improved, pretreatment here can be carried out according to conventional processing step, may include pre-filtering, It is one or more in precipitation, oxidation technology.Wherein pre-filtering is usually that can enumerate centrifugation mode, expression separation side Formula, filter type, floating separate mode, sedimentation separation mode.As the mode of centrifugation, horizontal continuous centrifugal point may be exemplified It disembarks (processing of spiral decanter), detach board-like centrifugal separator, filter centrifugal, tall building Pu Lesi type UCF ultracentrifuges, make For filter type, band filter, belt press, flypress, precoat filter, filter press are may be exemplified, is detached as floating Mode may be exemplified continuous floating separator, as sedimentation separation mode, may be exemplified agglutination sedimentation separation machine, sinks rapidly Seperator etc. is dropped, but is not particularly limited in above-mentioned any one.However it can be reduced by above-mentioned any one or combinations thereof To the load of film when secondary filter film and/or ultrafiltration membrane treatment.It is particularly preferred that sand filtration, more Jie may be used in pretreating process One or more combinations in matter filtering, activated carbon filtering.Here biofilter process refers to using with high-specific surface area Sorbing material as carrier in water macromolecular or other impurity be removed, carrier used herein above may be used often The organic or inorganic adsorbing material of rule, such as:The sorbing materials such as macroporous absorbent resin, zeolite, activated carbon;Bioactivity carbon filtration Using lower to flow pattern formula, water inlet dissolved oxygen content generally in 5~10mg/L or so, can fully ensure that biodegradation to dissolved oxygen in pond Demand;Two-part air-water backwashing may be used in filter tank, i.e., is discharged first with air bump rinse operation, again with the sand filtration of non-chlorination anti- Punching, backwashing period are 1~10 day;In biofilter if when being loaded using activated carbon as carrier, generally use iodine number and Asia First orchid adsorptive value carries out the standard of evaluation activated carbon, can be respectively 300~2000 mg/g and 50~500mg/g with adsorbance, living Property carbon build-up density can be 50~600g/L.Precipitation described here refers to by gravitational settling or in other outer force effects Under sedimentation using the method that detaches granule foreign with waste water, the method that may be used is sedimentation basin etc.;Oxidation is profit With pollutant in oxidizing Decomposition Wastewater, the method to purify waste water, when being handled using advanced oxidation, mainly Fenton Oxidizing process, ozone co-oxidation method, wet oxidation process, supercritical water oxidation method, photocatalytic oxidation and ultrasonic oxidation method etc. are several Class particularly preferably uses in ozonation technology, Fenton technology, microwave oxidation and one or more is combined processing.Using When ozone oxidation, ozone concentration can be 10~500ppm, and oxidizing temperature can be 10~50 DEG C;When using Fenton oxidation, Fe2+ And H2O2Concentration can be respectively 10~50mg/L and 20~900mg/L, and system pH is 3~6, and reaction temperature is 10~60 DEG C, Reaction time is 10~240min;When being aoxidized using microwave, 400~3000MHz of frequency, 10~60 DEG C of oxidizing temperature, processing 20~200min of time.The ultrafiltration used in pretreatment refers to being carried out to the colloid in water, big molecular impurity by ultrafiltration membrane The process of filter, " ultrafiltration membrane " in this specification refer to the filter membrane and/or molecular cut off that aperture is 0.001~0.01 μm For 1000~300000 or so filter membrane, inoranic membrane and organic film may be used in the material of ultrafiltration membrane, is further divided into thin Aqueous and hydrophily.As hydrophobic organic film, it is not limited to this, polysulfones can be enumerated, polyether sulfone, polyethers, gathered partially Difluoroethylene, polyethylene, polypropylene etc..As hydrophilic organic film, be not limited to this, can enumerate polyacrylonitrile, Polyamide, polyimides, cellulose acetate etc..Its filter core shape includes that flat membrane, tubular film, spiral membrane, doughnut are (hollow Silk) film etc..
Further, the salt concentration systems described in step 2, cycles of concentration is between 2~20 times, according to water inlet salinity Suitable cycles of concentration is selected, 10~40g/L of its salinity is for preferred salinity but according to salt component in water after concentration Difference and water inlet salinity variation can suitably adjust, which is not the decision condition of process implementing.The salt concentrate of step 2 System is using one or more process combinations in NF membrane concentration, reverse osmosis concentration, electrodialysis concentration.
NF membrane involved in institute of the invention is defined as " preventing the drive of the pressure of the particle less than 2nm and the macromolecular of dissolving The film of dynamic film ", can use cellulose acetate based polymer, polyamide, sulfonated polysulfone, polyacrylonitrile, polyester, polyimides and The high molecular materials such as polyvinyl.Reverse osmosis membrane in the present invention can use cellulose acetate Type of Collective object, polyamides The high molecular materials such as amine, polyester, polyimides, polyvinyl.The operating pressure of NF membrane can control 0.5~ 4.0MPa, the operating pressure of reverse osmosis membrane can control the range in 1.0MPa~10MPa.
Further, the purpose of the softening process of the 3rd step gets rid of the Ca in waste water2+、Mg2+It is soft that film can be used in ion Change, medicament softening(Such as NaOH and Na is added2CO3), ion exchange resin softening.
Further, the NaCl and Na in common middle water2SO4Concentration proportion cannot meet respectively crystallization obtain NaCl And Na2SO4Requirement when, NF membrane is used to that monovalent salt and the divalent salts ratio in high-salt wastewater to be adjusted by the present invention, is expired Sufficient NaCl and Na2SO4The requirement crystallized respectively recycles the mother liquor of crystallization process, reduces mother liquor amount, improves sal prunella The efficiency that joint process salt utilizes.The monovalent salt and divalent of high-purity are finally obtained while realizing brine waste zero emission Salt realizes the recycling of water and inorganic salts.NaCl and Na in the nanofiltration concentrated water of 4th step2SO4Mass concentration ratio 0.01 ~0.07 is selection process.
Further, the upgrading system again of the 6th step uses high pressure reverse osmosis membrane technique, DTRO techniques, electrodialysis process, MVR evaporation technologies or multiple-effect evaporation technique may be used.
Further, NaCl mass concentrations are between 10~20% after the nanofiltration fresh water of the 4th step concentrates.
Further, Na after the nanofiltration concentrated water concentration of the 4th step2SO4Mass concentration is between 8~15%.
Further, the 5th NaCl crystal systems, the Na described in step 6 step2SO4The evaporative crystallization that crystal system uses Technique is one kind in multiple-effect evaporation or MVR evaporations.
Further, the dedoping step described in step 7 step is using one in ozone oxidation, wet oxidation or light electrolysis oxidation Kind or multiple combinations technique.
Further, the reuse water system described in the 8th step can realize quality classification water supply according to each system producing water water quality, be used for It is one or more in boiler feedwater front end, industrial water, plant area's reclaimed water, recirculated water, landscape water.
Further, Na2SO4Crystal system mother liquor is re-fed into NaCl crystal systems after concentration and carries out at crystallization Reason, NaCl crystal system mother liquors are re-fed into Na after crossing concentration2SO4Crystal system carries out crystallization treatment.Due to the monovalence in waste water It can occur constantly to fluctuate with the concentration of divalent salts, and then influence whether the process of subsequent nanofiltration, crystallization so that technological parameter The variation for carrying out constantly being adapted to salinity in water is needed, therefore operating process can be caused unstable, crystal salt pure Degree cannot reach requirement.Meanwhile in NaCl and Na2SO4During crystallizing respectively, the NaCl and Na in feed liquid are crystallized2SO4's Concentration ratio difference is bigger, is more conducive to the crystal salt that crystallization process forms high-purity.Such as:In the process crystallized to NaCl In, the NaCl in crystal solution and Na2SO4Concentration proportion be C1(NaCl)/C1(Na2SO4), when by Na2SO4It is obtained after crystallization Mainly contain the mother liquor of NaCl(Concentration is calculated as C2And C (NaCl),2(NaCl)> C1(NaCl))Further added after concentration During being crystallized to NaCl, you can so that the concentration on the molecule of ratio increases, improve concentration proportion;According to numerical value Calculating could be aware that, as 10 < C1(NaCl)/C1(Na2SO4) < 100 when fluctuation, makes molecular concentration increase that can make in ranges The fluctuating range of whole ratio is obviously reduced, and plays the effect for stabilizing fluctuation.Similarly Na2SO4Crystallization process in, a divalent The concentration proportion of salt is C1(Na2SO4)/C1(NaCl), what is obtained after crystallizing NaCl mainly contains Na2SO4Mother liquor concentrations Afterwards, the C that will be obtained2(Na2SO4) concentrate is back to Na2SO4Crystallization process in after, due to C2(Na2SO4)> C1(Na2SO4), Similarly play the role of stabilizing crystallization process fluctuation of concentration.Therefore, by using reverse osmosis membrane to the mother liquor after crystallization It is returned again to the crystal system of upper level after further concentrate, can effectively make NaCl and Na2SO4Concentration ratio fluctuation Numerical value reduces, it is suppressed that the instable generation in crystallization process.
Based on above method, processing unit provided by the invention is as shown in Fig. 2, include:
Pretreatment system 1, for carrying out pretreatment removal of impurities to high-salt wastewater;
Concentration systems 2 are connected to pretreatment system 1, and the waste water for being obtained to pretreatment system 1 carries out concentration;
Melded system 3 is connected to concentration systems 2, for carrying out sofening treatment to the waste water after concentration;
NF membrane 4 is connected to melded system 3, the separation for carrying out a divalent salts to the production water after sofening treatment;
Sulfate crystal system 5 is connected to the dope side of NF membrane 4, for nanofiltration dope crystallization treatment, obtaining Na2SO4
Sodium chloride crystal system 6 is connected to the light liquid side of NF membrane 4, for the light liquid crystallization treatment of nanofiltration, obtaining NaCl.
In one embodiment, sulfate crystal system 5, mother liquor outlet be connected to sodium chloride crystal system 6, chlorination The mother liquor outlet of sodium crystal system 6 is connected to sulfate crystal system 5.
In one embodiment, the pretreatment system 1 includes pre-filtrating equipment, biofilter, oxidation unit, sinks One or more combinations in shallow lake device, oxidation unit or ultrafiltration apparatus.
In one embodiment, pre-filtrating equipment is sand filtering device, multi-medium filtering device or activated carbon filtering dress One or more combinations in setting.
In one embodiment, oxidation unit is ozone-oxidizing device, Fenton oxidation device or microwave oxidation unit In one or more combination biofilters refer to activated carbon bio-filter device.
In one embodiment, the concentration systems 2 include nanofiltration film condensing device, reverse osmosis concentrated compression apparatus or One or more combinations in electrodialysis enrichment facility.
In one embodiment, the light liquid side of NF membrane 4 is connect by enrichment facility with sodium chloride crystal system.
In one embodiment, enrichment facility is selected from high pressure reverse osmosis membrane apparatus, DTRO devices, electrodialysis plant, MVR The combination of one or more of vaporising device or multi-effect evaporating device.
Embodiment 1
Wastewater zero discharge and Nacl recycling are realized using nanofiltration and crystallization joint production process for certain pulp-making waste-water.Slurrying Waste water raw water day output is 40000 tons.Main water quality parameter see the table below:
Pulp-making waste-water raw water carries out in advance water using sand filtration and ozone, activated carbon bio-filter technique after the homogeneous of homogeneous pond Processing, ozone concentration 150ppm, ozone oxidation time 40min;Hydraulic detention time 15min;The activated carbon bio-filter charcoal height of bed Spend 2.0m, 25~30 DEG C for the treatment of temperature, air-land combat 20min;Waste water SS is down to 12~18mg/L after pretreatment, COD concentration is down to 45~53mg/L, and the pretreated water rate of recovery is more than 97%.
Enter ultrafiltration system, the molecular cut off 100kDa of ultrafiltration membrane, ultrafiltration work pressure by pretreated brine waste Power 0.3MPa, ultrafiltration operating flux 50L/(m2·h), the ultrafiltration membrane cleaning frequency is more than 90 days, and ultrafiltration production water SDI is turbid less than 2.5 Degree is less than 0.2NTU, and the ultrafiltration system rate of recovery is more than 93%.
Ultrafiltration production water enters first-stage reverse osmosis system, reverse osmosis operating pressure 1.5MPa, 30 DEG C of temperature, the reverse osmosis rate of recovery 65%, 15 L/ of average flux(m2·h), production water TDS is less than 105mg/L.Water yield per day is 24500m3.First-stage reverse osmosis concentrated water into Enter weak-acid ion exchange resin bed melded system, waste water hardness is down to 170 in 1200~1430mg/L after melded system ~187mg/L is down to 26mg/L by weak acid cation bed hardness, meets the reverse osmosis requirement of back segment.
Reverse osmosis concentrated water after softened enters two sections of counter-infiltration systems, reverse osmosis operating pressure 2.0MPa, 30 DEG C of temperature, Water inlet TDS is 10250~10560mg/L, and COD is 187~202mg/L, 3520~3640mg/L of sodium chloride concentration, and sodium sulphate is dense Spend 6300~6550mg/L, day output 13500m3.The water rate of recovery is 75%, fresh water yield 10120m3/ d, concentrated water amount 3380m3/d.It producing water TDS and is less than 210mg/L, concentrated water TDS is 40750~41300mg/L, sodium chloride concentration 13450 in concentrated water~ 13920mg/L, 24700~25530mg/L of sodium sulfate concentration, 392~434mg/L of hardness.Concentrated water is soft again by weak acid cation bed Hardness is reduced to 4~6mg/L after change.
Two-pass reverse osmosis concentrated water carries out inorganic salts ratio allotment by NF membrane, and operating pressure 54bar is handled through nanofiltration Afterwards, fresh water amount is 2910m3/ d, 14700~15340mg/L of sodium chloride concentration, 260~285mg/L of fresh water sodium sulfate concentration.It receives After filter fresh water uses high pressure is reverse osmosis and homogeneous membrane electrodialytic technique is further to concentrate, concentration liquid measure is 245m3/ d, sodium chloride are dense Spend 191100~203700mg/L, 5380~5500mg/L of sodium sulfate concentration.Nanofiltration concentrated water amount is 480m3/ d, sodium chloride concentration 11320~11890mg/L, 174200~17950mg/L of sodium sulfate concentration.
Nanofiltration fresh water is after reverse osmosis membrane concentrates, NaCl concentration 31100~31880mg/L, NaCl and Na2SO4Quality it is dense Degree is than about 53:1, meet the production requirement into NaCl crystallization processes sections.Sodium chloride crystal system uses triple effect evaporation, uses Advection feed-often imitates out the mode of operation of salt-mother liquor reflux, and control crystallization temperature is between 40~50 DEG C, in crystalline mother solution Na2SO4Mass concentration 5380mg/L, send to sulfate crystal system reuse, day obtains 45.7 tons of sodium chloride.Nanofiltration concentrated water into Enter sulfate crystal system, sulfate crystal system carries out Na using MVR techniques2SO4Crystallization, control crystallization temperature is 90~105 Between DEG C, Na2SO4Mass concentration ratio with NaCl is about 13:1, meet and enters Na2SO4The technological requirement of crystallization, crystalline mother solution The mass concentration 58400mg/L of middle NaCl is sent to sodium chloride crystal system reuse, which produces 82.5 tons of anhydrous sodium sulfate daily. The sodium chloride purity of two kinds of techniques reaches 98.3%, and sodium sulphate purity reaches 99.0%.
Using Nanofiltration-membrane technique in brine waste sodium chloride and sodium sulfate concentration be adjusted, fresh water and concentrated water chlorination Sodium and sodium sulphate ratio meet the requirement for carrying out sodium sulphate or sodium chloride joint production process, finally the zero-emission of realization waste water, and from The sodium chloride and sodium sulfate salt that can be recycled are obtained in waste water.
Embodiment 2
The existing Sewage Disposal of certain coal chemical industry enterprises one, wastewater discharge 2750m3/ h, waste water energy, which meets qualified discharge, to be wanted It asks.It is as follows to discharge water water quality index:
Inorganic salts ingredients are mainly sodium chloride and sodium sulphate in waste water.Zero-emission is carried out to waste water with crystallization joint production process using nanofiltration Put processing.
Coal chemical industrial waste water is delivered to zero-emission raw water after the homogeneous of homogeneous pond using sand filtration and ozone, activated carbon from plant area Absorbing process pre-processes water, ozone concentration 200ppm, ozone oxidation time 50min;20 DEG C of activated carbon adsorption temperature, Hydraulic detention time 12min;Waste water SS is down to 5~9mg/L after pretreatment, and COD concentration is down to 20~31mg/L, pretreatment The water rate of recovery is more than 98%.
Enter ultrafiltration system, the molecular cut off 50kDa of ultrafiltration membrane, ultrafiltration operating pressure by pretreated brine waste 0.4MPa, ultrafiltration operating flux 45L/(m2·h), the ultrafiltration membrane cleaning frequency is more than 60 days, and ultrafiltration produces water SDI and is less than 2, and turbidity is low In 0.3NTU, the ultrafiltration system rate of recovery is more than 92%.
Ultrafiltration production water enters first-stage reverse osmosis system, reverse osmosis operating pressure 2.0MPa, and the reverse osmosis rate of recovery 60% is averaged 15 L/ of flux(m2·h), production water TDS is less than 50 mg/L, water yield 1625m3/h.First-stage reverse osmosis concentrated water enters faintly acid Ion exchange resin bed melded system, waste water hardness drops 30~42mg/L, warp in 1050~1250mg/L after melded system It crosses weak acid cation bed hardness and is down to 4mg/L hereinafter, meeting the reverse osmosis requirement of back segment.
Reverse osmosis concentrated water after softened enters two sections of counter-infiltration systems, reverse osmosis operating pressure 1.5MPa, and water inlet TDS is 4700~5230mg/L, COD are 38~47mg/L, 735~920mg/L of sodium chloride concentration, 3860~4340mg/ of sodium sulfate concentration L, treating capacity 1150m3/h.The water rate of recovery is 75%, fresh water yield 860m3/ h, concentrated water amount 290m3/h.Production water TDS is less than 100mg/L, concentrated water TDS are 18500~20560mg/L, 2900~3130mg/L of sodium chloride concentration in concentrated water, sodium sulfate concentration 15460~17240mg/L, 76~85mg/L of hardness.
Two sections of reverse osmosis concentrated waters enter three sections of counter-infiltration systems, and water inlet TDS is 18500~19840mg/L, COD for 150~ 167mg/L, 2900~3170mg/L of sodium chloride concentration, 15460~16710mg/L of sodium sulfate concentration, treating capacity 290m3/h。 The water rate of recovery is 60%, fresh water yield 175m3/ h, concentrated water amount 115m3/h.It produces water TDS and is less than 400mg/L, concentrated water TDS is 46250~48220mg/L, 7050~7280mg/L of sodium chloride concentration, 38600~40530mg/L of sodium sulfate concentration in concentrated water, firmly Spend 76~87mg/L.
Three-level reverse osmosis concentrated water carries out inorganic salts ratio allotment by NF membrane, and operating pressure 48bar is handled through nanofiltration Afterwards, fresh water amount is 77m3/ h, 7120~7330mg/L of sodium chloride concentration, 390~419mg/L of fresh water sodium sulfate concentration.Nanofiltration is light After water uses high pressure is reverse osmosis and homogeneous membrane electrodialytic technique is further to concentrate, concentration liquid measure is 5.1m3/ h, sodium chloride concentration 106080~113500mg/L, 5840~6010mg/L of sodium sulfate concentration.Nanofiltration concentrated water amount is 38m3/ h, sodium chloride concentration 7035 ~7230mg/L, 115800~123400mg/L of sodium sulfate concentration.
Nanofiltration fresh water is after reverse osmosis membrane concentrates, NaCl and Na2SO4Mass concentration ratio be about 18:1, meet and enters chlorination The production requirement of sodium crystal system.Sodium chloride crystal system uses triple effect evaporation, and salt-mother liquor is often imitated out using advection charging- The mode of operation of reflux, control crystallization temperature is between 40~50 DEG C, Na in crystalline mother solution2SO4Mass concentration 3070mg/L, It send to sulfate crystal system reuse, day obtains 12.7 tons of sodium chloride.Nanofiltration concentrated water enters sulfate crystal system, sodium sulphate knot Crystallographic system system uses MVR techniques, and control crystallization temperature is between 90~105 DEG C, Na2SO4Mass concentration ratio with NaCl is about 16: 1, meet the technological requirement into sodium chloride and sodium sulphate, the mass concentration 33120mg/L of NaCl, send to chlorination in crystalline mother solution Sodium crystal system reuse, the technique produce 102.6 tons of anhydrous sodium sulfate daily.The sodium chloride purity of two kinds of techniques reaches 98.4%, sulfuric acid Sodium purity reaches 99.3%.
Using Nanofiltration-membrane technique in coal chemical industrial waste water sodium chloride and sodium sulfate concentration be adjusted, fresh water and concentrated water chlorine Change sodium and sodium sulphate ratio meets the requirement for carrying out sodium chloride and sulfate crystal technique, finally realizes the zero-emission of waste water, and The sodium chloride and sodium sulfate salt of technical grade are obtained from waste water.
Embodiment 3
Wastewater zero discharge and Nacl recycling are realized using nanofiltration and crystallization joint production process for certain pulp-making waste-water.Slurrying Waste water raw water day output is 40000 tons.Main water quality parameter see the table below:
Pulp-making waste-water raw water carries out in advance water using sand filtration and ozone, activated carbon bio-filter technique after the homogeneous of homogeneous pond Processing, ozone concentration 150ppm, ozone oxidation time 40min;Hydraulic detention time 15min;The activated carbon bio-filter charcoal height of bed Spend 2.0m, 25~30 DEG C for the treatment of temperature, air-land combat 20min;Waste water SS is down to 12~18mg/L after pretreatment, COD concentration is down to 45~53mg/L, and the pretreated water rate of recovery is more than 97%.
Enter ultrafiltration system, the molecular cut off 100kDa of ultrafiltration membrane, ultrafiltration work pressure by pretreated brine waste Power 0.3MPa, ultrafiltration operating flux 50L/(m2·h), the ultrafiltration membrane cleaning frequency is more than 90 days, and ultrafiltration production water SDI is turbid less than 2.5 Degree is less than 0.2NTU, and the ultrafiltration system rate of recovery is more than 93%.
Ultrafiltration production water enters first-stage reverse osmosis system, reverse osmosis operating pressure 1.5MPa, 30 DEG C of temperature, the reverse osmosis rate of recovery 65%, 15 L/ of average flux(m2·h), production water TDS is less than 105mg/L.Water yield per day is 24500m3.First-stage reverse osmosis concentrated water into Enter weak-acid ion exchange resin bed melded system, waste water hardness is down to 170 in 1200~1430mg/L after melded system ~187mg/L is down to 26mg/L by weak acid cation bed hardness, meets the reverse osmosis requirement of back segment.
Reverse osmosis concentrated water after softened enters two sections of counter-infiltration systems, reverse osmosis operating pressure 2.0MPa, 30 DEG C of temperature, Water inlet TDS is 10250~10560mg/L, and COD is 187~202mg/L, 3520~3640mg/L of sodium chloride concentration, and sodium sulphate is dense Spend 6300~6550mg/L, day output 13500m3.The water rate of recovery is 75%, fresh water yield 10120m3/ d, concentrated water amount 3380m3/d.It producing water TDS and is less than 210mg/L, concentrated water TDS is 40750~41300mg/L, sodium chloride concentration 13450 in concentrated water~ 13920mg/L, 24700~25530mg/L of sodium sulfate concentration, 392~434mg/L of hardness.Concentrated water is soft again by weak acid cation bed Hardness is reduced to 4~6mg/L after change.
Two-pass reverse osmosis concentrated water carries out inorganic salts ratio allotment by NF membrane, and operating pressure 54bar is handled through nanofiltration Afterwards, fresh water amount is 2910m3/ d, 14700~15340mg/L of sodium chloride concentration, 260~285mg/L of fresh water sodium sulfate concentration.It receives After filter fresh water uses high pressure is reverse osmosis and homogeneous membrane electrodialytic technique is further to concentrate, concentration liquid measure is 245m3/ d, sodium chloride are dense Spend 191100~203700mg/L, 5380~5500mg/L of sodium sulfate concentration.Nanofiltration concentrated water amount is 480m3/ d, sodium chloride concentration 11320~11890mg/L, 174200~17950mg/L of sodium sulfate concentration.
Nanofiltration fresh water is after reverse osmosis membrane concentrates, NaCl concentration 31100~31880mg/L, NaCl and Na2SO4Quality it is dense Degree is than about 53:1, meet the production requirement into NaCl crystallization processes sections.Sodium chloride crystal system uses triple effect evaporation, uses Advection feed-often imitates out the mode of operation of salt-mother liquor reflux, and control crystallization temperature is between 40~50 DEG C, crystalline mother solution warp Na after high pressure reverse osmosis concentration2SO4Mass concentration 217710mg/L, send to sulfate crystal system reuse, day obtains sodium chloride 48.6 tons.Nanofiltration concentrated water enters sulfate crystal system, and sulfate crystal system carries out Na using MVR techniques2SO4Crystallization, control Crystallization temperature is between 90~105 DEG C, Na2SO4Mass concentration ratio with NaCl is about 13:1, meet and enters Na2SO4Crystallization Technological requirement, the mass concentration 63320mg/L of crystalline mother solution middle NaCl after high pressure reverse osmosis concentration, send to sodium chloride system of crystallization System reuse, the technique produce 84.7 tons of anhydrous sodium sulfate daily.The sodium chloride purity of two kinds of techniques reaches 99.0%, and sodium sulphate purity reaches To 99.4%.
Using Nanofiltration-membrane technique in brine waste sodium chloride and sodium sulfate concentration be adjusted, fresh water and concentrated water chlorination Sodium and sodium sulphate ratio meet the requirement for carrying out sodium sulphate or sodium chloride joint production process, finally the zero-emission of realization waste water, and from The sodium chloride and sodium sulfate salt that can be recycled are obtained in waste water.

Claims (10)

1. a kind of high-salinity wastewater zero-emission method, which is characterized in that include the following steps:
1st step cleans the preprocessed system of brine waste;
2nd step carries out concentration to the waste water that the 1st step obtains;
3rd step carries out sofening treatment to the waste water that the 2nd step obtains;
4th step is handled the waste water that the 3rd step obtains using nanofiltration membrane, adjusts the NaCl and Na in waste water2SO4Concentration ratio Example;
The concentrated water of 5th step, NF membrane is sent into Na2SO4Crystal system obtains Na by Crystallization Separation2SO4Nacl and the first mother Liquid;The fresh water of NF membrane is concentrated and then is sent into NaCl crystal system, by Crystallization Separation obtain NaCl Nacls with And second mother liquor;
6th step, the first mother liquor, which is sent into NaCl crystal systems, carries out crystallization treatment, and the second mother liquor is sent into Na2SO4Crystal system into Row crystallization treatment.
2. high-salinity wastewater zero-emission method according to claim 1, which is characterized in that pretreatment system is discharged in the 1st step COD is between 10~200mg/L, and SS is in 3~50mg/L;Pretreatment in 1st step refers to pre-filtering, biofilter, precipitation, oxygen One or more combinations in change or ultrafiltration;Pre-filtering is one kind in sand filtration, multi-medium filtering or activated carbon filtering Or a variety of combination;Biofilter refers to activated carbon bio-filter;Oxidation using ozonation technology, Fenton oxidation technology or One or more combinations in microwave oxidation.
3. high-salinity wastewater zero-emission method according to claim 1, which is characterized in that concentration makes TDS in waste water exist 20~60g/L;Concentration process is using one or more technique groups in NF membrane concentration, reverse osmosis concentration or electrodialysis concentration It closes.
4. high-salinity wastewater zero-emission method according to claim 1, which is characterized in that melded system goes out hydraulic in the 3rd step Degree is between 20~200mg/L;One kind in film softening, medicament softening or ion exchange resin softening can be used in softening process Or kinds of processes combination.
5. high-salinity wastewater zero-emission method according to claim 1, which is characterized in that in the 4th step, in NF membrane concentrated water NaCl and Na2SO4The concentration mass ratio of concentration(0.01~0.07):1;Na in the concentrated water of NF membrane2SO4Mass concentration 8~ 15%;In 5th step, the fresh water of NF membrane carry out concentration be using high pressure reverse osmosis membrane technique, DTRO techniques, electrodialysis process, The combination of one or more of MVR evaporation technologies or multiple-effect evaporation technique;NaCl mass concentrations exist after the concentration of NF membrane fresh water Between 10~20%.
6. high-salinity wastewater zero-emission method according to claim 1, which is characterized in that sulfate crystal mother liquor is by concentration It is re-fed into later in NaCl crystal systems and carries out crystallization treatment, Na is re-fed into after the contracting of chlorination mother liquid of sodium overrich2SO4Crystal system Carry out crystallization treatment.
7. a kind of high-salinity wastewater zero-emission processing unit, which is characterized in that including:
Pretreatment system(1), for carrying out pretreatment removal of impurities to high-salt wastewater;
Concentration systems(2), it is connected to pretreatment system(1), for pretreatment system(1)Obtained waste water carries out at concentration Reason;
Melded system(3), it is connected to concentration systems(2), for carrying out sofening treatment to the waste water after concentration;
NF membrane(4), it is connected to melded system(3), the separation for carrying out a divalent salts to the production water after sofening treatment;
Sulfate crystal system(5), it is connected to NF membrane(4)Dope side obtain for nanofiltration dope crystallization treatment Na2SO4
Sodium chloride crystal system(6), it is connected to NF membrane(4)Light liquid side obtain for the light liquid crystallization treatment of nanofiltration NaCl。
8. high-salinity wastewater zero-emission processing unit according to claim 11, which is characterized in that sulfate crystal system (5), mother liquor outlet be connected to sodium chloride crystal system(6), sodium chloride crystal system(6)Mother liquor outlet be connected to sodium sulphate Crystal system(5);The pretreatment system(1)Including pre-filtrating equipment, biofilter, oxidation unit, settler, oxidation One or more combinations in device or ultrafiltration apparatus;Pre-filtrating equipment be sand filtering device, multi-medium filtering device or One or more combinations in active carbon filtering device;Oxidation unit is ozone-oxidizing device, Fenton oxidation device or micro- One or more combination biofilters in wave oxidation unit refer to activated carbon bio-filter device;The concentration systems (2)Including one or more combinations in nanofiltration film condensing device, reverse osmosis concentrated compression apparatus or electrodialysis enrichment facility.
9. high-salinity wastewater zero-emission processing unit according to claim 7, which is characterized in that NF membrane(4)Light liquid side It is connect with sodium chloride crystal system by enrichment facility.
10. high-salinity wastewater zero-emission processing unit according to claim 9, which is characterized in that enrichment facility is selected from high pressure The group of one or more of reverse osmosis membrane apparatus, DTRO devices, electrodialysis plant, MVR vaporising devices or multi-effect evaporating device It closes.
CN201810778712.4A 2018-07-16 2018-07-16 A kind of high-salinity wastewater zero-emission processing method and processing device based on NF membrane allotment Pending CN108623104A (en)

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109516625A (en) * 2018-12-05 2019-03-26 北京环球中科水务科技有限公司 A kind of processing method of high salt organic waste water
CN109607574A (en) * 2019-01-03 2019-04-12 中国中轻国际工程有限公司 A kind of strong brine production sal prunella technique
WO2020223829A1 (en) * 2019-05-09 2020-11-12 Investigaciones Forestales Bioforest S.A. Method for recovering water and chemicals from plants for treating effluents from pulp and paper factories
CN112875976A (en) * 2021-02-07 2021-06-01 天津工业大学 Preparation method for recycling inorganic salt in printing and dyeing wastewater

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109516625A (en) * 2018-12-05 2019-03-26 北京环球中科水务科技有限公司 A kind of processing method of high salt organic waste water
CN109607574A (en) * 2019-01-03 2019-04-12 中国中轻国际工程有限公司 A kind of strong brine production sal prunella technique
WO2020223829A1 (en) * 2019-05-09 2020-11-12 Investigaciones Forestales Bioforest S.A. Method for recovering water and chemicals from plants for treating effluents from pulp and paper factories
CN112875976A (en) * 2021-02-07 2021-06-01 天津工业大学 Preparation method for recycling inorganic salt in printing and dyeing wastewater

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