A kind of method of multistage electrically-driven ion film process high slat-containing wastewater
Technical field
The present invention relates to sewage recycling field, particularly relate to by multistage electrically-driven ion film process high slat-containing wastewater field.
Background technology
In recent years, in the fast development of the industries such as petrochemical industry, electric power, metallurgy, Coal Chemical Industry, the reverse osmosis concentrated water produced in Industrial processes, industrial sewage, circulating sewage and some processes draining etc. increase year by year containing the sewage quantity of complicated component, and the sewage of these high complicated components how ultimate disposal and Utilizing question is paid attention to widely.
Current reverse osmosis technology is very fast for the treatment of waste water development ratio, but still has a large amount of making not to be effectively utilized after being through reverse-osmosis treated, and reclaims the high cost of wherein contained salt by evaporative crystallization.Reverse-osmosis membrane element is easily by Organic pollutants in addition, is tending towards saturated inorganic salt calcium, magnesium compound easily in face generation scale problems, thus affects the work-ing life of reverse-osmosis membrane element, reduces filter effect.
Chinese patent CN104355431A discloses the equipment that a kind of reverse osmosis concentrated water and high slat-containing wastewater efficiently process recovery.This equipment carries out depth type filtration purification to the fresh water obtained by reverse osmosis membrane after tentatively being filtered by two-stage vibration film, and tympanum filters the dense water obtained and then reclaims salt by evaporative crystallization.Not useless water softening is except wet goods measure, although shorten treatment process, lower to the organic efficiency of salt and fresh water.And after the process of two-stage vibration membrane concentration in dense water the content of water still higher, it is too high that evaporative crystallization reclaims the cost of salt.
Summary of the invention
For the deficiency of prior art, the invention provides a kind of method of multistage electrically-driven ion film process high slat-containing wastewater, it is characterized in that, described method is by after carrying out pre-treatment to high slat-containing wastewater, carry out osmosis filtration and electrically-driven ion membrane separation again, to reclaim de-salted water expeditiously.
Wherein said preprocessing process is made heavy metal ion, hardness ions and the organic substance in order to remove in high slat-containing wastewater by precipitation and/or flocculation adsorption and is regulated pH, obtains pretreated dense water.
Described osmosis filtration process carries out preliminary minimizing process to described pretreated dense water, to obtain the dense water of moderate by middle pressure osmosis filtration and high pressure osmosis filtration.
Described electrically-driven ion membrane separating process carries out the degree of depth by one-level electric drive film handling procedure, secondary electric drive film handling procedure and three grades of electric drive film handling procedures to the dense water of described moderate and concentrates, obtain high dense water with minimizing, thus be convenient to evaporative crystallization recovery salt.
Wherein said one-level electric drive film treating processes adopts monovalent cation selective membrane and univalent anion selective membrane, thus the monovalent cation isolated in the dense water of moderate and univalent anion, at the dense water of moderate of the salt that dense hydroecium acquisition monovalent cation and univalent anion are formed, obtain the main dense water of moderate containing high-valence cationic and/or high-valence anion after being separated at freshwater room.
The described dense water containing high-valence cationic and/or high-valence anion concentrates the dense water of height obtaining high price salt further by secondary electric drive film handling procedure, to carry out evaporative crystallization recovery,
The dense water of salt that described monovalent cation and univalent anion are formed concentrates the dense water of height obtaining salt at a low price further through three grades of electric drive film handling procedures, to carry out evaporative crystallization recovery,
In wherein said secondary electric drive film handling procedure and three grades of electric drive film handling procedures, the pressure of dense hydroecium is all than the pressure height 0.1-0.4MPa of freshwater room.
According to one preferred embodiment, described monovalent cation is sodium ion, and described univalent anion is chlorion, and described high-valence anion is sulfate ion.Described low price salt is sodium-chlor, and described high price salt is vitriol.Preferred described high price salt is sodium sulfate.
Described one-level electric drive film treating processes adopts monovalent cation selective membrane to obtain the dense water of sodium-chlor and the main dense water containing vitriol with univalent anion selective membrane to be separated.
The described main dense water containing vitriol enters secondary electric drive film handling procedure, further the concentrated dense water of height obtaining vitriol, thus directly carries out evaporative crystallization recovery.
The dense water of described sodium-chlor enters three grades of electric drive film handling procedures, further the concentrated dense water of height obtaining sodium-chlor, thus directly carries out evaporative crystallization recovery.
In wherein said secondary electric drive film handling procedure and three grades of electric drive film handling procedures, the pressure of dense hydroecium is all than the pressure height 0.2-0.35MPa of freshwater room.
The organism of the hardness ions of fouling, heavy metal ion and easy polluted membrane is removed by pre-treatment, the work-ing life of the film in reverse-osmosis filtering device is increased greatly, also mitigate the burden of follow-up osmosis filtration and electric drive membrane sepn in addition, making to filter increases with the efficiency be separated, and the rate of recovery of fresh water is improved.
By selectivity electrically-driven ion membrane sepn sodium-chlor and vitriol, after the electric drive film degree of depth concentrates minimizing, directly carry out evaporative crystallization afterwards obtain sodium-chlor and vitriol.
Through the multistage minimizing process of reverse-osmosis treated and electrically-driven ion film, in dense water, salts contg raises greatly, thus alleviates the burden that evaporative crystallization reclaims salt, also makes fresh water reclaim more abundant.
According to one preferred embodiment, described one-level electric drive film device adopts NeoseptaCMS monovalent cation selective membrane and NeoseptaACS univalent anion selective membrane.
According to one preferred embodiment, the dense hydroecium pressure of described secondary electric drive film device and three grades of electric drive film devices is all higher than the pressure of freshwater room.
According to one preferred embodiment, the pressure difference of the dense hydroecium of described secondary electric drive film device and freshwater room is 0.25MPa-0.35MPa, and the dense hydroecium of described three grades of electric drive film devices and the pressure difference of freshwater room are 0.2MPa-0.3MPa,
According to one preferred embodiment, after preprocessing process, the TDS value of described dense water is 0.1 × 10
4mg/L ~ 1 × 10
4mg/L, after osmosis filtration process, the TDS value of the dense water of described moderate is 1 × 10
4mg/L ~ 6 × 10
4mg/L, after electrically-driven ion membrane separating process, the TDS value of the dense water of described height is 1 × 10
5mg/L ~ 3 × 10
5mg/L.
According to one preferred embodiment, after preprocessing process, the TDS value of described dense water is 0.5 × 10
4mg/L ~ 1 × 10
4mg/L, after osmosis filtration process, the TDS value of the dense water of described moderate is 5 × 10
4mg/L ~ 6 × 10
4mg/L, after electrically-driven ion membrane separating process, the TDS value of the dense water of described height is 1.2 × 10
5mg/L ~ 2 × 10
5mg/L.
According to one preferred embodiment, after the process of one-level electric drive film, the TDS value of the high dense water of described sodium-chlor and the high dense water of vitriol is about 1 × 10
5mg/L, after the film process of secondary electric drive and the process of three grades of electric drive films, the TDS value of the high dense water of described sodium-chlor and the high dense water of vitriol is about 2 × 10
5mg/L.
Most water has been reclaimed by reverse osmosis process, the waste water of high saliferous is obtained concentrated, again after the process of two-stage electric drive film, further recovery fresh water also makes waste water advanced concentrated, by minimizing process, thus greatly reduce the water yield needing evaporation when salt is reclaimed in crystallization, save energy consumption, and improve the rate of recovery of water and salt.
According to one preferred embodiment, all there is hard porous film support component to make liquid stream homogenizing in the freshwater room of described secondary electric drive film device and three grades of electric drive film devices, chaotic stream is there is and can mix in liquid at the film support component through porous, and add the distance that liquid flows through, extend the residence time of liquid, make separation more abundant.Film support component is that electric drive film provides support power, makes pressure that film is subject to more even, balances the osmotic pressure of dense hydroecium, prevent electric drive film impaired under stress.
According to one preferred embodiment, film support component is porous stone and/or sponge plastics.Preferably, described film support component is filled in freshwater room.
According to one preferred embodiment, the effective porosity on described film support component surface is greater than 50%.
According to one preferred embodiment, described film support component is by the fixing porous cloth of stereoplasm frame.Described porous cloth is fixed in freshwater room, near electric drive film or fit with electric drive film.
According to one preferred embodiment, described porous cloth is the fabric that glass fibre and/or flaxen fiber are made.
According to one preferred embodiment, the hole on described film support component is the irregular hole be interconnected.
According to one preferred embodiment, the fresh water obtained in described electrically-driven ion membrane separating process carries out osmosis filtration process again with further separate fresh and salt.The water inlet of electrically-driven ion membrane separating process is the dense water of moderate that saltiness is higher, and isolated fresh water saltiness is also slightly high, by carrying out again reverse-osmosis treated to it to increase the rate of recovery of salt.
According to one preferred embodiment, described middle pressure osmosis filtration process employing width of flow path is the middle pressure reverse osmosis unit of 50mil-70mil, and described high pressure osmosis filtration process employing width of flow path is the high pressure reverse osmosis unit of 70mil-90mil.
According to one preferred embodiment, described middle pressure osmosis filtration process employing width of flow path is the middle pressure reverse osmosis unit of 65mil, and described high pressure osmosis filtration process employing width of flow path is the high pressure reverse osmosis unit of 80mil.Make osmosis filtration element that fouling or organic fouling not easily occur by large runner design.
According to one preferred embodiment, described preprocessing process comprises by adding pretreating agent and carry out precipitating and/or after flocculation adsorption tentatively discharging mud, more again discharges mud by micro-filtration, to obtain described dense water.
According to one preferred embodiment, described preprocessing process comprises pre-treatment treatment, micro-filtration process and resin except hard process, to generate dense water.By resin except hardness ions in desat waste water, prevent fouling on the film in reverse osmosis process.What preferred described micro-filtration process adopted is tubular type micro-filtration or immersed microfiltration device.Preferred described resin is Zeo-karb.
According to one preferred embodiment, described preprocessing process removes organism, silicon ion, magnesium ion and/or calcium ion by precipitation and/or flocculation adsorption effect and regulates the pH of dense water in alkalescence, to prevent fouling and scaling in reverse osmosis process.
According to one preferred embodiment, described pretreating agent comprises one or more in lime, sodium hydroxide, sodium carbonate, polymerize aluminum chloride and polyacrylamide flocculant.
According to one preferred embodiment, described preprocessing process is for add sodium hydroxide, sodium carbonate, polymerize aluminum chloride and polyacrylamide flocculant successively, reacted by sodium hydroxide and sodium carbonate and heavy metal ion and hardness ions and generate throw out and regulate the PH of waste water, by polymerize aluminum chloride and polyacrylamide flocculant, coagulation and absorption are carried out to throw out and organic substance, become sludge settling to get off under gravity.Described sludge settling is discharged in the bottom of pretreatment unit, and supernatant liquor enters tubular type micro-filtration and further filters, and removes throw out residual in waste water, prevents from causing detrimentally affect to follow-up reverse-osmosis filtering device and electrically-driven ion membrane separation unit.
According to one preferred embodiment, the PH of the dense water of described pre-treatment is 7.5-10.0.
According to one preferred embodiment, the PH of the dense water of described pre-treatment is 8.0-9.5, and the PH of the dense water of preferred described pre-treatment is 8.5-9.0.Alkaline condition can suppress the tendency of silicon fouling on reverse osmosis membrane surface and Organic pollutants.
According to one preferred embodiment, the dense water of described moderate will carry out except hard process through resin before entering electrically-driven ion membrane separating process, and preferred described resin is Zeo-karb.
According to one preferred embodiment, described mud forms dewatered sludge by filter-press dehydration, and the water deviate from enters preprocessing process and again processes.
According to one preferred embodiment, to, through cartridge filter, prevent foreign material from causing detrimentally affect to device before described waste water presses reverse-osmosis filtering device, high pressure reverse-osmosis filtering device, one-level electric drive film device and/or secondary electric drive film device in entering.
According to one preferred embodiment, the reverse osmosis membrane of described middle pressure reverse-osmosis filtering device and/or described high pressure reverse-osmosis filtering device adopts aromatic polyamide matrix material.
According to one preferred embodiment, the working pressure of described middle pressure reverse-osmosis filtering device is 1.5-4MPa, and the working pressure of described high pressure reverse-osmosis filtering device is 3-5MPa.In preferred, the working pressure of pressure reverse-osmosis filtering device is 2.0-3.5MPa, and the working pressure of described high pressure reverse-osmosis filtering device is 3.5-4.5MPa.
According to one preferred embodiment, the dense water of described height carries out evaporative crystallization reclaim(ed) sulfuric acid sodium and sodium-chlor by steam mechanical recompression.
According to one preferred embodiment, described method first carries out flocculation sediment remove portion organism by the pretreating agent adding alkalescence, silicon ion, dense water is obtained after magnesium ion and/or calcium ion, be in 65mil, press reverse osmosis unit and width of flow path to be that the high pressure reverse osmosis unit of 80mil carries out osmosis filtration by width of flow path successively again, carry out preliminary minimizing process to reclaim fresh water, the dense water of the moderate that reverse osmosis obtains is separated monovalent ion and high valence ion by one-level electric drive film device, to obtain the dense water of sodium-chlor respectively at dense hydroecium, the main dense water containing vitriol is obtained with at freshwater room, wherein said one-level electric drive film device adopts NeoseptaCMS monovalent cation selective membrane and NeoseptaACS univalent anion selective membrane, the described main dense water containing vitriol is by the secondary electric drive film device concentrated dense water of height obtaining vitriol further, the pressure height 0.3MPa of the pressure ratio freshwater room of the dense hydroecium of wherein said secondary electric drive film device, the dense water of described sodium-chlor is by three grades of electric drive film devices concentrated dense water of height obtaining sodium-chlor further, the pressure height 0.2MPa of the pressure ratio freshwater room of wherein said three grades of dense hydroeciums of electric drive film device, the freshwater room of described secondary electric drive film device and three grades of electric drive film devices all containing porous stone and/or sponge plastics as film support component to prevent electric drive film impaired under stress, the fresh water obtained in described electrically-driven ion membrane separating process carries out osmosis filtration process again with further separate fresh and salt.
The method of multistage electrically-driven ion film process high slat-containing wastewater provided by the invention, by carrying out pre-treatment removing heavy metal ion, hardness ions and organism etc. wherein to high slat-containing wastewater, prevents the detrimentally affect that fouling or fouling membrane etc. cause reverse osmosis unit.Coordinated by two steps ro device and three grades of electrically-driven ion film sole duties, stage treatment waste water, substantially increase the organic efficiency of fresh water, by the degree of depth is concentrated, minimizing process is carried out to waste water simultaneously, alleviate evaporation burden when saline crystallization reclaims, the method is simple, fresh water and the salt rate of recovery high, cost is low.
Accompanying drawing explanation
Fig. 1 is the process flow sheet of the present invention's multistage electrically-driven ion film process high slat-containing wastewater; With
Fig. 2 is the system and device schematic diagram of the present invention's multistage electrically-driven ion film process high slat-containing wastewater.
Reference numerals list
10: preprocessing process 61: sodium sulfate reclaims
11: homogeneous all measures process 62: sodium-chlor reclaims
12: pre-treatment treatment 101: equalizing tank
13: micro-filtration process 102: highly dense pond
14: one-level sofening treatment 103: tubular type micro-strainer
20: preliminary minimizing process 104: one-level resin container
21: middle pressure osmosis filtration 201: middle pressure reverse osmosis unit
22: high pressure osmosis filtration 202: high pressure reverse osmosis unit
23: secondary softening process 203: second resin tank
30: depth minus quantizing process 301: one-level electric drive film device
31: one-level electric drive film process 302: secondary electric drive film device
32: secondary electric drive film process 303: three grades of electric drive film devices
33: three grades of electric drive films process 401: return water tank
40: fresh water removal process 501: sludge sump
50: sludge handling process 601: sodium sulfate retrieving arrangement
60: salt removal process 602: sodium-chlor retrieving arrangement
Embodiment
Be described in detail below in conjunction with accompanying drawing.
Embodiment
As depicted in figs. 1 and 2, multistage electrically-driven ion film process high slat-containing wastewater technique of the present invention comprises preprocessing process 10, preliminary minimizing process 20, depth minus quantizing process 30, fresh water removal process 40, sludge handling process 50 and salt removal process 60.
Wherein in preprocessing process 10, high slat-containing wastewater carries out entering highly dense pond 102 after homogeneous all measures process 11 in equalizing tank 101, in highly dense pond 102, carry out pre-treatment treatment 12.In highly dense pond 102, sodium hydroxide, sodium carbonate, PAC and PAM solution is added successively successively by chemicals dosing plant.Wherein sodium hydroxide is mixed with the solution of 20% concentration, and dosage is 1.5g/L, and sodium carbonate is mixed with the solution of 15% concentration, and dosage is 3g/L, for carrying out chemical precipitation reaction demineralized water; PAC is made into the solution of 20% concentration, and dosage is the solution that 30mg/L, PAM are made into 0.3% concentration, and dosage is 3mg/L, for the particle carrying out coagulation and adsorb organic compound and be settled out.Chemical feeding quantity is unsuitable excessive, need adjust, otherwise easily cause fouling membrane, affect the work-ing life of film according to each ionic concn changing conditions in the actual water inlet of water quality.
The mud produced under gravity enters sludge sump 501 from the bottom in highly dense pond 102 and carries out sludge handling process 50, and supernatant liquor enters into tubular type micro-strainer 103 or micro-filtration process 13 is carried out in immersed microfiltration pond, with further disgorging.Wherein filter tank total hrt is 2.5h.The mud produced enters in sludge sump 501 equally, and filtrate enters in one-level resin container 104 carries out one-level sofening treatment 14.
Wherein tubular type micro-strainer 103 adopts the low pressure of 0.07-0.7MPa, adopts the mode of cross-flow to filter simultaneously.Under low pressure solid particulate is deposited in film surface film surface cross-flow passes is constantly concentrated along with solidliquid mixture, thus isolates the high concentration suspended solid in liquid.
Mud wherein in sludge sump 501 carries out mud-water separation by press filtration.The dewatered sludge produced carries out final recovery or emission treatment, and the water deviate from then returns in highly dense pond 102 or equalizing tank 101 and again processes.
Sulfonic acid ion exchange resin and/or carboxylic acid type cation exchange resin is adopted, further except the calcium, magnesium etc. in anhydrating easily causes the ion of fouling in one-level resin container 104.The dense water generated enters preliminary minimizing process 20.TDS content wherein in dense water, i.e. dissolvability solid amount, generally 0.5 × 10
4mg/L to 1.0 × 10
4the scope of mg/L.
According to one preferred embodiment, at equalizing tank 101, highly dense pond 102, tubular type micro-strainer 103, be separately installed with topping-up pump and/or lift pump between one-level resin container 104 and middle pressure reverse osmosis unit 201, in order to shift high slat-containing wastewater successively between the various devices.
According to one separately preferred embodiment, between tubular type micro-strainer 103 and one-level resin container 104, and between one-level resin container 104 and middle pressure reverse osmosis unit 201, intermediate pool and topping-up pump are also installed, intermediate pool is in order to collect and temporarily to store the high slat-containing wastewater after upper stage arrangement process, and topping-up pump is in order to transfer to the high slat-containing wastewater in intermediate pool in low-level device.
In preliminary minimizing process 20, dense water enters middle pressure reverse osmosis unit 201 and carries out middle pressure osmosis filtration 21, and the product water accounted for into water total amount more than 70% enters return water tank 401, enters fresh water removal process 40; The reverse osmosis dope accounted for into water total amount 30% enters high pressure reverse osmosis unit 202.After high pressure osmosis filtration 22, the product water accounted for into water total amount more than 65% enters return water tank 401, enters fresh water removal process 40; The reverse osmosis dope accounted for into water total amount 35% enters in second resin tank 203 and carries out secondary softening process 23.Sulfonic acid ion exchange resin and/or carboxylic acid type cation exchange resin is adopted, further except the calcium, magnesium etc. in anhydrating easily causes the ion of fouling in second resin tank 203.The moderate dense water penetration depth minimizing process 30 generated.
Wherein, pressure reverse osmosis unit 201 adopts press mold element in the concentrated antipollution of GTR3-8040F-65 type special type, and width of flow path is 65mil, is about 1.65mm; High pressure reverse osmosis unit 202 adopts the concentrated antipollution high-pressure membrane element of GTR4-8040F-80 type special type, and width of flow path is 80mil, is about 2.03mm.After preliminary minimizing process, the TDS of the dense water of moderate can reach about 5 × 10
4mg/L.Now the rate of recovery of fresh water reaches about 85%.
According to one preferred embodiment, at middle pressure reverse osmosis unit 201, high pressure reverse osmosis unit 202, between second resin tank 203 and one-level electric drive film device 301, intermediate pool and topping-up pump are installed, intermediate pool is in order to collect and temporarily to store the high slat-containing wastewater after upper stage arrangement process, and topping-up pump is in order to transfer to the high slat-containing wastewater in intermediate pool in low-level device.
According to a preferred embodiment of the present invention, between high pressure reverse osmosis unit 202 and second resin tank 203, also activated charcoal filter is installed.Reverse osmosis dope after filtration enters second resin tank 203 after activated charcoal filter filters to carry out sofening treatment and obtains the dense water of moderate.
According to another preferred embodiment of the present invention, middle pressure reverse osmosis unit 201 and high pressure reverse osmosis unit 202 are respectively containing cartridge filter, before high slat-containing wastewater to be filtered presses reverse osmosis unit 201 in entering and before entering high pressure reverse osmosis unit 202, need enter cartridge filter respectively and carry out security personnel's filtration, removing may cause dysgenic gritty particle to reverse osmosis unit.
In depth minus quantizing process 30, the dense water of moderate enters one-level electric drive film device 301, isolates monovalent cation and univalent anion through one-level electric drive film process 31, obtains the dense water of sodium-chlor at dense hydroecium, obtains the dense water of vitriol at freshwater room.
The dense water of vitriol enters secondary electric drive film device 302, through secondary electric drive film process 32, further concentrates.The wherein pressure height 0.35MPa of the pressure ratio freshwater room of the dense hydroecium of secondary electric drive film device 302 employing.The dense water of sodium-chlor enters three grades of electric drive film devices 303, through three grades of electric drive films process 33, further concentrates.The pressure height 0.3MPa of the pressure ratio freshwater room of the dense hydroecium of three grades of electric drive film device 303 employings.
For preventing film to be out of shape under stress and impaired, near the film of freshwater room side, be provided with film support component.This film support component is by the fixing porous cloth of stereoplasm frame.The stretch-proof performance of the stretch-proof Performance Ratio electric drive film of this porous cloth preferred is good; namely the deformation of the deformation ratio electric drive film of this porous cloth is at the same pressure little; thus protection electric drive film can not to differ from large deformation because of its pressure at both sides excessive and impaired, also ensure that the volume ratio of the dense hydroecium of electric drive film device and freshwater room is relatively stable simultaneously.This porous cloth preferred is the fabric that natural flaxen fiber is made.
Wherein, secondary electric drive film process 32 and three grades of electric drive films process 33 are isolated respectively and are accounted for into water total amount 85% de-salted water, and this de-salted water returns preliminary minimizing process 20 and again processes.This de-salted water preferred returns middle pressure reverse osmosis unit 201 and mixes with dense water and carry out osmosis filtration.According to of the present invention another preferred embodiment, this de-salted water returns high pressure reverse osmosis unit 202 and again carries out osmosis filtration program.
The isolated high dense water of sodium-chlor accounted for into water weight 15% is about 2 × 10 with the TDS value accounted for into the high dense water of vitriol of water weight 15%
5mg/L.The high dense water of described sodium-chlor and the high dense water of vitriol enter the reclaimer of sodium-chlor and vitriol respectively.
According to one preferred embodiment, between one-level electric drive film device 301 and secondary electric drive film device 302, between one-level electric drive film device 301 and three grades of electric drive film devices 303, between secondary electric drive film device 302 and sodium sulfate retrieving arrangement 601, and between three grades of electric drive film devices 303 and sodium-chlor retrieving arrangement 602, be separately installed with intermediate water tank and topping-up pump, intermediate pool is in order to collect and temporarily to store the high slat-containing wastewater after upper stage arrangement process, and topping-up pump is in order to transfer to the high slat-containing wastewater in intermediate pool in low-level device.
According to another preferred embodiment of the present invention, one-level electric drive film device 301, secondary electric drive film device 302 and three grades of electric drive film devices 303 are respectively containing cartridge filter, high slat-containing wastewater to be filtered is before entering one-level electric drive film device 301, secondary electric drive film device 302 and three grades of electric drive film devices 303, need enter cartridge filter respectively and carry out security personnel's filtration, removing may cause dysgenic gritty particle to electric drive film device.
Adopt steam mechanical recompression in salt reclaimer 60, namely MVR technology carry out evaporative crystallization concentrate, to isolate sodium sulfate and/or sodium-chlor.Salt reclaimer 60 comprises sodium sulfate and reclaims 61 and sodium-chlor recovery 62.The dense water inventory of height entering salt reclaimer 60 account for high slat-containing wastewater total amount less than 5%.The high dense water of this sodium sulfate and the high dense water of sodium-chlor enter sodium sulfate retrieving arrangement 601 and sodium-chlor retrieving arrangement 602 respectively, after preheating, enter evaporative crystallizer, utilize recycle pump to carry out circulating-heating to feed liquid and well heater.
When sodium sulfate reclaims 61, under negative pressure state, raw steam is utilized to provide preliminary heat to heat the high dense water of sodium sulfate to boiling, then the low temperature secondary dead steam utilizing evaporation to produce is undertaken by vapour compressor compressing the temperature improving exhaust steam, substitute raw steam and circulating-heating is carried out to feed liquid, realize the saline solution be continuously in nitre tank and heat energy is provided.Secondary high-temperature steam after compression, after heat exchanger heat exchange, becomes high-temperature condensation water, after entering one-level preheater and feed liquid heat exchange, is condensed into cryogenic condensation water, delivers to return water tank 401 and enters fresh water removal process 40.
Reach oversaturated feed liquid to discharge from evaporative crystallizer, enter one-level thickener, the ten water nitre be separated with follow-up freezing nitre mix and carry out hot melt, be separated obtain nitre through centrifugation apparatus.Mother liquor after nitre is separated reaches-5 degree through freezing, is separated and obtains ten water nitre, returns last unit and supersaturation feed liquid and carries out hot melt and isolate nitre.The stoste that remaining mother liquor is separated as sodium-chlor, mixes with the high dense water of sodium-chlor entering sodium-chlor and reclaim 62 programs, enters sodium-chlor retrieving arrangement 602, after preheating, enter in sodium-chlor evaporative crystallizer.
When sodium-chlor reclaims 62, by the high dense water of raw steam heating sodium-chlor to boiling, Low Temperature Steam after utilizing vapour compressor to extract evaporation, compression improves its temperature, substitute raw steam and continuous heating is carried out to stoste, salt cellar is under negative pressure state, and continue to carry out water yield evaporation concentration, feed temperature maintains about 108 degree.To the temperature lower water of condensation of the high-temperature condensation water that well heater produces after the heat exchange of secondary preheater, delivers to return water tank 401 and enters fresh water removal process 40.
According to salt-water system Na
+/ Cl
-, SO
4 2-the content of main ingredient in-H2O phasor, makes to reach oversaturated sodium-chlor and discharges from salt evaporative crystallizer, enter secondary thickener, be separated obtain sodium-chlor through centrifugation apparatus.
The water entered in fresh water removal process 40 reaches the water quality of process water substantially, can directly again utilize, or utilizes after further purifying treatment.
Indices change (mg/L) in table 1 treating processes of the present invention
Table 1 show adopt process of the present invention high slat-containing wastewater Central Plains water, CODCr, TDS, total hardness, Cl in dense water after pre-treatment water outlet and minimizing
-, SO
4 2-, Ca
2+, Mg
2+, Na
+change in concentration.As can be seen from the above table with Na
+ion is that benchmark calculates, and the rate of recovery of method water of the present invention can reach 96%, and the rate of recovery of salt reaches more than 96%.
It should be noted that; above-mentioned specific embodiment is exemplary; those skilled in the art can find out various solution under the inspiration of the disclosure of invention, and these solutions also all belong to open scope of the present invention and fall within protection scope of the present invention.It will be understood by those skilled in the art that specification sheets of the present invention and accompanying drawing thereof are illustrative and not form limitations on claims.Protection scope of the present invention is by claim and equivalents thereof.