CN109956579A - The preprocess method and system of coal-burning power plant's desulfurization wastewater with high salt - Google Patents

The preprocess method and system of coal-burning power plant's desulfurization wastewater with high salt Download PDF

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Publication number
CN109956579A
CN109956579A CN201711407552.4A CN201711407552A CN109956579A CN 109956579 A CN109956579 A CN 109956579A CN 201711407552 A CN201711407552 A CN 201711407552A CN 109956579 A CN109956579 A CN 109956579A
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water
order reaction
level
filtering
carries out
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Inventor
钟振成
熊日华
李国涛
程子洪
陈权
刘捷
段亚威
霍卫东
李永龙
卫昶
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Shenhua Group Corp Ltd
National Institute of Clean and Low Carbon Energy
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Shenhua Group Corp Ltd
National Institute of Clean and Low Carbon Energy
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    • CCHEMISTRY; METALLURGY
    • C01INORGANIC CHEMISTRY
    • C01FCOMPOUNDS OF THE METALS BERYLLIUM, MAGNESIUM, ALUMINIUM, CALCIUM, STRONTIUM, BARIUM, RADIUM, THORIUM, OR OF THE RARE-EARTH METALS
    • C01F11/00Compounds of calcium, strontium, or barium
    • C01F11/46Sulfates
    • 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
    • C01INORGANIC CHEMISTRY
    • C01PINDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2006/00Physical properties of inorganic compounds
    • C01P2006/80Compositional purity
    • 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
    • C02F1/50Treatment of water, waste water, or sewage by addition or application of a germicide or by oligodynamic treatment
    • 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
    • C02F1/66Treatment of water, waste water, or sewage by neutralisation; pH adjustment
    • CCHEMISTRY; METALLURGY
    • C02TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02FTREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F2101/00Nature of the contaminant
    • C02F2101/10Inorganic compounds
    • CCHEMISTRY; METALLURGY
    • 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
    • C02F2103/18Nature of the water, waste water, sewage or sludge to be treated from the purification of gaseous effluents
    • CCHEMISTRY; METALLURGY
    • C02TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02FTREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F2303/00Specific treatment goals
    • C02F2303/04Disinfection
    • 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
    • C02F5/08Treatment of water with complexing chemicals or other solubilising agents for softening, scale prevention or scale removal, e.g. adding sequestering agents

Abstract

The present invention relates to the field of purification of coal-burning power plant's desulfurization wastewater with high salt, disclose the preprocess method and system of coal-burning power plant's desulfurization wastewater with high salt.Method includes: that (1) is added lime to desulfurization wastewater and carries out first order reaction, and isolated level-one clear water and level-one sludge;(2) level-one clear water is subjected to pH adjusting, obtains the second order reaction liquid that pH value is 6-8;(3) second order reaction liquid is subjected to calcium ion removing, wherein the process of calcium ion removing includes: addition sodium sulphate, then successively carries out the crystal of calcium sulfate separation under second order reaction and room temperature, obtains second level clear water and secondary sludge;(4) fungicide is added to second level clear water and carries out filtering processing, obtain filtering and produce water;(5) water addition antisludging agent and antisludging agent deactivator are produced to filtering and carries out ion isolation, obtained high concentration salt water and pretreatment produces water;Wherein, high concentration salt water is returned and step (3) progress calcium ion removing is added.Desulphurization for Coal-fired Power Plant Wastewater Pretreatment cost can be effectively reduced.

Description

The preprocess method and system of coal-burning power plant's desulfurization wastewater with high salt
Technical field
The present invention relates to the field of purification of coal-burning power plant's desulfurization wastewater with high salt, and in particular to coal-burning power plant's desulfurization wastewater with high salt Preprocess method and system.
Background technique
Overwhelming majority power plant, China, coal plant are using the SO in Wet Limestone Desulfurization technology removing flue gas2, thus The desulfurization wastewater of generation becomes one of most intractable waste water in coal-burning power plant because complicated component, pollutant kind.It is domestic at present Mainly using chemical precipitation method (being commonly called as three headers precipitating) processing desulfurization wastewater, processing water outlet salt content is higher, direct emission After be easy to cause secondary pollution.Simultaneously as desulfurization wastewater water is smaller, salt content is high, power plant, coal plant's desulfurization wastewater into The process system long-play of one step processing is unstable, and (water inlet microsolubility inorganic salt content is high, causes ultrafiltration nanofiltration reverse osmosis Scaling situation is serious), and operating cost is higher, thus at present without practical application example.But as Environmental Protection in China requires Further reinforcing, the exploitation of the further zero discharge treatment technology of desulfurization wastewater is extremely urgent, need reduce process system Technological innovation and technological development are carried out in terms of cost and raising process system stability.
The prior art is in purification coal-burning power plant desulfurization wastewater with high salt, although the monovalence in waste water, divalent ion can be removed, But two class ions are mostly to remove together, the salt of formation is that many kinds of substance mixes, and is not effectively separated monovalent ion and divalent Ion, the compound for being unfavorable for the ion of removing further utilize.The process operation cost of the prior art is also higher simultaneously, increases The burden of power plant emission processing, the scheme of urgent need to resolve.
Summary of the invention
The purpose of the invention is to overcome removing product of the existing technology impure, process operation higher cost is asked Topic, provides the preprocess method and system of coal-burning power plant's desulfurization wastewater with high salt, this method and systematic difference can be effectively The monovalent ion and divalent ion in desulfurization wastewater are separated, and the higher calcium sulfate of purity can be recycled, and coal-burning power plant can be reduced Desulfurization wastewater with high salt purifies pretreated operating cost.
To achieve the goals above, first aspect present invention provides a kind of pretreatment side of coal-burning power plant's desulfurization wastewater with high salt Method, comprising:
(1) lime is added to desulfurization wastewater and carries out first order reaction, obtained first order reaction product is separated by solid-liquid separation through level-one Obtain level-one clear water and level-one sludge;
(2) the level-one clear water is subjected to pH adjusting, obtains the second order reaction liquid that pH value is 6-8;
(3) the second order reaction liquid is subjected to calcium ion removing, wherein the process of the calcium ion removing includes: to be added Then sodium sulphate successively carries out the crystal of calcium sulfate separation under second order reaction and room temperature, obtains second level clear water and secondary sludge;
(4) Xiang Suoshu second level clear water is added fungicide and carries out filtering processing, obtains filtering and produces water;
(5) Xiang Suoshu filtering produces water and antisludging agent and antisludging agent deactivator is added and carries out ion isolation, obtains high salt concentration Water and pretreatment produce water;
Wherein, the high concentration salt water is returned and step (3) progress calcium ion removing is added.
Preferably, in step (1), the additional amount of lime makes the pH 10.5-12 of the first order reaction product.
Preferably, the temperature of the first order reaction is 10-30 DEG C, and the pressure of the first order reaction is 0.02-0.1MPa, The time of the first order reaction is 60-180min.
Preferably, in step (3), the additional amount of sodium sulphate makes the total hardness of the second level clear water be 10-40mmol/ L。
Preferably, in step (3), the temperature of the second order reaction is 10-30 DEG C, and the pressure of the second order reaction is 0.02-0.1MPa, the time of the second order reaction are 120-360min.
Preferably, in step (4), the fungicide is selected from sodium hypochlorite and/or hydrogen peroxide;The addition of the fungicide Amount is the 1-20 mass ppm of the second level clear water.
Preferably, in step (4), the filtering processing is ultrafiltration and/or sand filtration.
Preferably, in step (4), the SDI value that the filtering produces water is 1 or less.
Preferably, in step (5), the antisludging agent is nanofiltration or reverse osmosis membrane antisludging agent, the antisludging agent deactivator choosing From ferric trichloride and/or hydrogen peroxide.
Preferably, in step (5), the additional amount of the antisludging agent is the 1-20 mass ppm that the filtering produces water, the resistance The additional amount of dirty agent deactivator is the 1-20 mass ppm that the filtering produces water.
Preferably, in step (5), the ion isolation is nanofiltration separation.
Preferably, nanofiltration separation temperature is 10-30 DEG C, and nanofiltration separation pressure is 0.8-1.5MPa, and the pretreatment produces water Water yield be the filtering produce water 30-70%.
Preferably, the weight ratio of the second order reaction liquid and the high concentration salt water is (1.5-3.5): 1.
Second aspect of the present invention provides a kind of system of coal-burning power plant's desulfurization wastewater with high salt, comprising: first order reaction unit 1, Acidity adjustment unit 2, second order reaction unit 3, filtering unit 4 and ion isolation unit 5;
The first order reaction unit is used to that lime to be added to desulfurization wastewater and carries out first order reaction, and isolated level-one is clear Water and level-one sludge;
The acidity adjustment unit is used to level-one clear water progress pH being adjusted to second order reaction liquid;
The second order reaction unit is used to that sodium sulphate to be added to the second order reaction liquid and carries out calcium ion removing, and separates Obtain second level clear water and secondary sludge;
The filtering unit is used to that fungicide to be added to the second level clear water and carries out filtering processing, obtains filtering and produces water;
The ion isolation unit is used to produce water to the filtering and antisludging agent and antisludging agent deactivator is added and carries out ion Separation, obtains high concentration salt water and pretreatment produces water;
The high salt concentration water out of the ion isolation unit is connected to the entrance of the second order reaction unit, and being used for will be described High concentration salt water is passed through the second order reaction unit and carries out the calcium ion removing.
Through the above technical solutions, the purification that the present invention takes substep to carry out coal-burning power plant's desulfurization wastewater with high salt pre-processes, Substep delivering medicament lime and sodium sulphate may be implemented to efficiently separate monovalent ion and high valence ion in desulfurization wastewater, monovalence Ion enrichment produces in water in finally obtained pretreatment, is further processed removing monovalent ion by downstream process.And two Valence ion can be deposited in the level-one sludge and secondary sludge that this method obtains, then dirty through corresponding level-one Treatment of Sludge and second level Mud handles to obtain the higher calcium sulfate byproduct of purity, uses for architecture of high quality or food gypsum, raising desulfurization wastewater are net The increment effect of change.While efficiently separating the monovalent ion and divalent ion in desulfurization wastewater, method of the invention and it is Unite the substep operation taken, launch lime and sodium sulphate, the operation of entire technique normal temperature and pressure, reduce the operation of entire technique at This.
Detailed description of the invention
Fig. 1 is the preprocess method of coal-burning power plant provided by the invention desulfurization wastewater with high salt and the flow diagram of system.
Description of symbols
1, first order reaction unit 2, acidity adjustment unit 3, second order reaction unit
4, filtering unit 5, ion isolation unit 6, level-one sludge treating block
7, secondary sludge processing unit
Specific embodiment
The endpoint of disclosed range and any value are not limited to the accurate range or value herein, these ranges or Value should be understood as comprising the value close to these ranges or value.For numberical range, between the endpoint value of each range, respectively It can be combined with each other between the endpoint value of a range and individual point value, and individually between point value and obtain one or more New numberical range, these numberical ranges should be considered as specific open herein.
First aspect present invention provides a kind of preprocess method of coal-burning power plant's desulfurization wastewater with high salt, comprising:
(1) lime is added to desulfurization wastewater and carries out first order reaction, obtained first order reaction product is separated by solid-liquid separation through level-one Obtain level-one clear water and level-one sludge;
(2) the level-one clear water is subjected to pH adjusting, obtains the second order reaction liquid that pH value is 6-8;
(3) the second order reaction liquid is subjected to calcium ion removing, wherein the process of the calcium ion removing includes: to be added Then sodium sulphate successively carries out the crystal of calcium sulfate separation under second order reaction and room temperature, obtains second level clear water and secondary sludge;
(4) Xiang Suoshu second level clear water is added fungicide and carries out filtering processing, obtains filtering and produces water;
(5) Xiang Suoshu filtering produces water and antisludging agent and antisludging agent deactivator is added and carries out ion isolation, obtains high salt concentration Water and pretreatment produce water;
Wherein, the high concentration salt water is returned and step (3) progress calcium ion removing is added.
The desulfurization wastewater that the present invention is handled can be the waste water from Desulphurization for Coal-fired Power Plant device, can be through waste-water vortex The desulfurization wastewater discharged after device eddy flow, wherein including organic matters and the nothings such as a large amount of suspended matter, calcium sulfate, magnesium sulfate, sodium chloride Machine salt impurity.Wherein, calcium ions and magnesium ions, chloride ion content are high.Method provided by the invention, which can be effectively removed in waste water, to be existed Above-mentioned impurity, and monovalence and divalent ion in waste water can be separated, such as separate magnesium ion, calcium ion, sulfate ion with Chloride ion, improves the water quality of the desulfurization wastewater, and obtains the calcium sulfate of purity is high, and has the advantage of low cost.
The preferably manageable desulfurization wastewater of method provided by the invention, composition can be 400- containing concentration The sodium ion of 1500mg/L, the chloride ion of 4000-15000mg/L, 3000-8000mg/L sulfate ion, 1000- The calcium ion of 3000mg/L and the magnesium ion of 1500-5000mg/L.
The above-mentioned multistep of method provided by the invention point, and delivering medicament lime and sodium sulphate in two steps, realize the desulfurization Monovalence and divalent ion in waste water can be effectively separated, and monovalent ion stays in finally obtained pretreatment and produces in water, can To facilitate technique and the equipment in downstream to isolate monovalent ion.And divalent ion is removed in level-one sludge and secondary sludge, And the higher calcium sulfate of the available purity of secondary sludge, be conducive to subsequent high value added utilization.
In the present invention, step (1) is mainly used for that the Mg in the desulfurization wastewater can be reduced2+, especially noncarbonate Mg2+It generates Mg (OH)2Precipitating, while most of Si can also be reduced.Preferably, in step (1), the additional amount of lime makes described The pH of first order reaction product is 10.5-12.Wherein lime can be added in the form of concentration is the lime solution of 8-12 weight %. The first order reaction product is solidliquid mixture.
In the present invention, the condition of the first order reaction can complete the precipitating of magnesium ion, can be in the normal of mild condition It is carried out under normal temperature and pressure;It can be in stirred tank and carry out.Preferably, the temperature of the first order reaction is 10-30 DEG C, and the level-one is anti- The pressure answered is 0.02-0.1MPa, and the time of the first order reaction is 60-180min.
In the present invention, flocculant and flocculation aid can also be added in (1) in step.It can be flocculation commonly used in the art Agent and flocculation aid do not have to specific restriction, can be preferably polyacrylamide, Polyferric Sulfate etc..Additional amount reaches the flocculating effect of needs , can be this field conventional amount used, as flocculant and flocculation aid can distinguish the 1-20 matter that dosage is the desulfurization wastewater Measure ppm.
The first order reaction product is also subjected to the level-one separation of solid and liquid, isolated method in step (1) of the invention It can be and stand the first order reaction product and filter, obtaining solid is level-one sludge, wherein it is rich in divalent ion, such as Mg2+.It can be with Mg in the level-one clear water2+Concentration reduce, such as can be with Mg2+Concentration be 10mg/L or less.
The composition for the level-one clear water that method provided by the invention preferably obtains can be 3500- containing concentration The sodium ion of 4500mg/L, the chloride ion of 4000-15000mg/L, 5000-6000mg/L sulfate ion, 4000- The calcium ion of 5000mg/L and the magnesium ion of 20-40mg/L.
In step (2) of the invention, the pH value for the level-one clear water that adjustable step (1) obtains is described to be suitble to Second order reaction.It is excessive wherein to adjust pH value, is unfavorable for the whole implementation of method of the invention, can not achieve the present invention can be rear Selective Separation calcium ion in continuous step, obtains the gypsum of high-quality.Such as pH value is greater than 11, then can also contain in level-one sludge Calcium sulfate precipitation is unfavorable for the gypsum that the secondary sludge that the present invention designs obtains high-quality.Being added can for the pH reagent adjusted To be selected from sulfuric acid or hydrochloric acid solution, the concentrated solution or weak solution of sulfuric acid or hydrochloric acid can be.
In the present invention, step (3) is used to the suitably described second order reaction liquid of pH value further removing divalent ion.Pass through Sodium sulphate, which is added, can mainly isolate the Ca in the second order reaction liquid2+, generate CaSO4.The CaSO generated simultaneously4In second level Solubility in reaction solution reaches supersaturation and crystalline deposit is precipitated from the second order reaction liquid, then through the second level solid-liquid point From obtaining secondary sludge.The secondary sludge obtained in this way is through the available purity of further Treatment of Sludge up to 96.0% or more Gypsum can satisfy for building or food standard, there is higher added value.Preferably, in step (3), sodium sulphate adds Entering amount makes the total hardness of the second level clear water be 10-40mmol/L.Total hardness refers to the total concentration of calcium ion and magnesium ion, single Position is scaled mmol/L.Wherein sodium sulphate can be added in the form of concentration is the metabisulfite solution of 8-12 weight %.
In the present invention, participate in step (3) further include being recycled back to from downstream the high concentration salt water.Preferably, The weight ratio of the second order reaction liquid and the high concentration salt water is (1.5-3.5): 1.It is possible thereby to improve by the calcium from Son removing reduces Ca in the second order reaction liquid2+Effect, be better achieved separation desulfurization waste liquor in divalent ion.Sodium sulphate It can be and be added in the mixture of the second order reaction liquid and the high concentration salt water.
In the present invention, the calcium ion removing can carry out at normal temperatures and pressures.Divalent ion in the desulfurization wastewater, Predominantly Ca2+It can be isolated in the form of crystal of calcium sulfate.Preferably, in step (3), the temperature of the second order reaction is 10-30 DEG C, the pressure of the second order reaction is 0.02-0.1MPa, and the time of the second order reaction is 120-360min.
In the present invention, a large amount of oversaturated sulfuric acid will be formed in the second order reaction product that obtains by the second order reaction Calcium separates through the crystal of calcium sulfate under room temperature, calcium sulfate is discharged in secondary sludge, plays the role of removing calcium ion.Herein Room temperature can be preferably 10-35 DEG C.
Further include that second level is separated by solid-liquid separation in step (3) of the invention, obtains secondary sludge and second level clear water.Secondary sludge is rich Containing Ca2+, and calcium sulfate purity is high, the gypsum product of high-quality can be done.
In the present invention, the second level clear water that step (3) obtains further reduced Ca2+Content, can be with Ca2+Concentration be 1000mg/L or less.
In the present invention, flocculant and flocculation aid can also be added in (3) in step.It can be flocculation commonly used in the art Agent and flocculation aid do not have to specific restriction, can be preferably polyacrylamide, Polyferric Sulfate etc..Additional amount reaches the flocculating effect of needs , can be this field conventional amount used, as flocculant and flocculation aid can distinguish the 1-20 that dosage is the second order reaction liquid The 1-20 mass ppm of the mixture of quality ppm or the second order reaction liquid and the high concentration salt water.
The composition for the second level clear water that method provided by the invention preferably obtains can be 6500- containing concentration The sodium ion of 7500mg/L, the chloride ion of 4000-15000mg/L, 200-300mg/L sulfate ion, 800-1000mg/L Calcium ion and 20-40mg/L magnesium ion.
In the present invention, step (4) can be used for further removing the suspended matter and colloid in the second level clear water, be downstream The step of (5) provide can be applicable in ion isolation charging.Preferably, in step (4), the fungicide is selected from sodium hypochlorite And/or hydrogen peroxide;The additional amount of the fungicide is the 1-20 mass ppm of the second level clear water.
In the present invention, the condition of the filtering processing guarantees to obtain the charging for being suitble to the ion isolation.Preferably, In step (4), the filtering processing is ultrafiltration and/or sand filtration;Preferably, in step (4), the SDI value that the filtering produces water is 1 or less.SDI value is the pollution index value of water quality indicator, can be measured according to ASTM method 4189-95 using SDI instrument.
In the present invention, step (5) can be used for being additionally separated out the filtering produce in water there is likely to be divalent Or more ion.Preferably, in step (5), the antisludging agent is nanofiltration or reverse osmosis membrane antisludging agent;The antisludging agent adds Entering amount is the 1-20 mass ppm that the filtering produces water.The antisludging agent is known substance, can be commercially available, such as nail (unit of length) section The pc-191 of company, Ondeo Nalco Co. OSM-60.
Preferably, the antisludging agent deactivator is selected from ferric trichloride and/or hydrogen peroxide;The antisludging agent deactivator adds Entering amount is the 1-20 mass ppm that the filtering produces water.
In the present invention, the condition of the ion isolation completes to separate divalent and the above ion and one in the filtering production water Valence ion.Preferably, in step (5), the ion isolation is nanofiltration separation;Preferably, nanofiltration separation temperature is 10-30 DEG C, nanofiltration separation pressure is 0.8-1.5MPa, and the pretreatment produces the 30-70% that the water yield of water produces water for the filtering.It is excellent Selecting the pretreatment to produce the water yield of water is that the filtering produces the 50% of water.The pretreatment can be significantly improved and produce monovalence in water The rate of recovery of ion.The nanofiltration membrane component that the nanofiltration separation uses is known substance, can be commercially available.Such as GE DL system Column nanofiltration membrane component, GE SWSR series nanofiltration membrane component, DOW NF270 series nanofiltration membrane component or TCK company, South Korea NE8040-40 nanofiltration membrane component.Ion isolation through above-mentioned condition, the pretreatment produce water contain total concentration be 1mmol/L with Under calcium ion and sulfate ion.Meanwhile the high concentration salt water contain total concentration be 90 weight % or more calcium ion and Sulfate ion.
The composition that the pretreatment that method provided by the invention preferably obtains produces water can be 6500- containing concentration The sodium ion of 7500mg/L, the chloride ion of 4000-15000mg/L, the sulfate ion of 150-300mg/L, 100-250mg/L The magnesium ion of calcium ion and 0.1-11mg/L.
In the present invention, the preprocess method can also include at the level-one sludge and secondary sludge that will be obtained Reason, prevents secondary pollution.The method of processing, which can be, to be entered grey field for the level-one sludge and secondary sludge blending or admixes stone In cream semi-finished product.Wherein, the secondary sludge is through handling the gypsum of available 96.0% or more purity.
Second aspect of the present invention provides a kind of system of coal-burning power plant's desulfurization wastewater with high salt, comprising: first order reaction unit 1, Acidity adjustment unit 2, second order reaction unit 3, filtering unit 4 and ion isolation unit 5;
The first order reaction unit is used to that lime to be added to desulfurization wastewater and carries out first order reaction, and isolated level-one is clear Water and level-one sludge;
The acidity adjustment unit is used to level-one clear water progress pH being adjusted to second order reaction liquid;
The second order reaction unit is used to that sodium sulphate to be added to the second order reaction liquid and carries out calcium ion removing, and separates Obtain second level clear water and secondary sludge;
The filtering unit is used to that fungicide to be added to the second level clear water and carries out filtering processing, obtains filtering and produces water;
The ion isolation unit is used to produce water to the filtering and antisludging agent and antisludging agent deactivator is added and carries out ion Separation, obtains high concentration salt water and pretreatment produces water;
The high salt concentration water out of the ion isolation unit is connected to the entrance of the second order reaction unit, and being used for will be described High concentration salt water is passed through the second order reaction unit and carries out the calcium ion removing.
In the present invention, the first order reaction unit may include lime adding apparatus, the first reaction vessel and separation equipment, Such as lime investment adder, pot type are stirred to react settler, sludge remover apparatus etc..
In the present invention, the acidity adjustment unit may include acid solution supply device, pot type stirred reactor.
In the present invention, the second order reaction unit may include sodium sulphate investment adder, pot type be stirred to react settler, Sludge remover apparatus.
In the present invention, the filtering unit may include fungicide adding apparatus, sand filter, ultrafiltration apparatus.
In the present invention, the ion isolation unit may include scale inhibitor adding apparatus, antisludging agent deactivator adding apparatus, Nanofiltration membrane separation device.
The present invention can also include level-one sludge treatment equipment 6 and secondary sludge processing unit 7.
It is connected between each unit, device, equipment or the container for including in the present invention by pipeline, to complete coal-burning power plant's height Salt desulfurization wastewater removes out divalent and the above ion and monovalent ion, obtains satisfactory pretreatment and produces water.
The present invention will be described in detail by way of examples below.
The composition of coal-burning power plant's desulfurization wastewater with high salt is as shown in table 1.
Table 1
Embodiment 1
It is with high salt that coal-burning power plant's desulfurization wastewater (flow 20t/h) with high salt of composition such as table 1 is passed through coal-burning power plant shown in FIG. 1 The system of desulfurization wastewater, in first order reaction unit be added concentration be 10 weight % lime solution, at 25 DEG C, 0.1MPa into The pH of row first order reaction 120min, the first order reaction product that lime solution additional amount makes reach 10.5;
Then first order reaction product is stood and is obtained by filtration level-one sludge and level-one clear water, the composition of level-one clear water As shown in table 2;
20% salt acid for adjusting pH value of concentration is added in level-one clear water and obtains second order reaction liquid for 7, while downstream ion is added The weight ratio of isolated high concentration salt water, second order reaction liquid and high concentration salt water is 1.5:1;
To the metabisulfite solution that concentration is 8 weight % is added in second order reaction liquid and high concentration salt water, 10 DEG C, Second order reaction 360min is carried out under 0.1MPa, and carries out crystal of calcium sulfate precipitating, and it is solid that obtained second order reaction product carries out second level Liquid separation, obtains secondary sludge and second level clear water, and the additional amount of metabisulfite solution keeps the composition of second level clear water as shown in table 2, The hardness of middle second level clear water is in the range of 10-40mmol/L;
The sodium hypochlorite for the 5 mass ppm that dosage is second level clear water is added into second level clear water, and carries out ultrafiltration (GE company The ultrafiltration apparatus of offer), it obtains filtering and produces water, SDI value is 0.5;
Water being produced to filtering, the hydrogen peroxide that dosage is the 20 mass ppm that filtering produces water being added, dosage is that filtering produces the 10 of water Then quality ppm antisludging agent deactivator pc-191 carries out nanofiltration ion isolation (Tao Shi NF270-2540 film), obtains high concentration Salt water and pretreatment produce water, and the water yield of pretreatment production water is the 50 weight % that filtering produces water;Pretreatment produces water composition and 2 institute of table Show;High concentration salt water, which returns, participates in above-mentioned second order reaction.
Secondary sludge obtains calcium sulfate, purity 96.0% through processing.
Through cost accounting, processing cost is about 8.67 yuan/ton.
Embodiment 2
It is with high salt that coal-burning power plant's desulfurization wastewater (flow 20t/h) with high salt of composition such as table 1 is passed through coal-burning power plant shown in FIG. 1 The system of desulfurization wastewater, in first order reaction unit be added concentration be 12 weight % lime solution, at 10 DEG C, 0.1MPa into The pH of row first order reaction 60min, the first order reaction product that lime solution additional amount makes reach 12;
Then first order reaction product is stood and is obtained by filtration level-one sludge and level-one clear water, the composition of level-one clear water As shown in table 2;
15% sulfuric acid solution of concentration adjusting pH value is added in level-one clear water and obtains second order reaction liquid for 8, while downstream is added The weight ratio of the high concentration salt water that ion isolation obtains, second order reaction liquid and high concentration salt water is 3.5:1;
To the metabisulfite solution that concentration is 8 weight % is added in second order reaction liquid and high concentration salt water, 20 DEG C, Second order reaction 120min is carried out under 0.1MPa, and carries out crystal of calcium sulfate precipitating, and it is solid that obtained second order reaction product carries out second level Liquid separation, obtains secondary sludge and second level clear water, and the additional amount of metabisulfite solution keeps the composition of second level clear water as shown in table 2, The hardness of middle second level clear water is in the range of 10-40mmol/l;
The sodium hypochlorite for the 10 mass ppm that dosage is second level clear water is added into second level clear water, and carries out ultrafiltration (Hang Zhoushui The ultrafiltration apparatus that processing equipment company provides), it obtains filtering and produces water, SDI value is 0.8;
Water being produced to filtering, the ferric trichloride that dosage is the 5 mass ppm that filtering produces water being added, dosage is 20 matter that filtering produces water Ppm antisludging agent deactivator pc-191 is measured, then nanofiltration ion isolation (Tao Shi NF270-2540 film) is carried out, obtains high salt concentration Water and pretreatment produce water, and the water yield of pretreatment production water is the 30 weight % that filtering produces water;Pretreatment produces water composition and 2 institute of table Show;High concentration salt water, which returns, participates in above-mentioned second order reaction.
Secondary sludge obtains calcium sulfate, purity 98% through processing.
Through cost accounting, processing cost is about 10 yuan/ton.
Embodiment 3
It is with high salt that coal-burning power plant's desulfurization wastewater (flow 20t/h) with high salt of composition such as table 1 is passed through coal-burning power plant shown in FIG. 1 The system of desulfurization wastewater, in first order reaction unit be added concentration be 8 weight % lime solution, at 30 DEG C, 0.1MPa into The pH of row first order reaction 180min, the first order reaction product that lime solution additional amount makes reach 11;
Then first order reaction product is stood and is obtained by filtration level-one sludge and level-one clear water, the composition of level-one clear water As shown in table 2;
It is that adjust pH value be 6 to obtain second order reaction liquid to 15% hydrochloric acid solution by level-one clear water addition concentration, while under being added The weight ratio of the isolated high concentration salt water of free son, second order reaction liquid and high concentration salt water is 2:1;
To the metabisulfite solution that concentration is 8 weight % is added in second order reaction liquid and high concentration salt water, 30 DEG C, Second order reaction 240min is carried out under 0.1MPa, and carries out crystal of calcium sulfate precipitating, and it is solid that obtained second order reaction product carries out second level Liquid separation, obtains secondary sludge and second level clear water, and the additional amount of metabisulfite solution keeps the composition of second level clear water as shown in table 2, The hardness of middle second level clear water is in the range of 10-40mmol/l;
The hydrogen peroxide for the 5 mass ppm that dosage is second level clear water is added into second level clear water, and carries out ultrafiltration (GE company The ultrafiltration apparatus of offer), it obtains filtering and produces water, SDI value is 0.6;
Water being produced to filtering, the ferric trichloride that dosage is the 10 mass ppm that filtering produces water being added, dosage is 5 matter that filtering produces water Ppm antisludging agent deactivator OSM-60 is measured, then nanofiltration ion isolation (Tao Shi NF270-2540 film) is carried out, obtains high salt concentration Water and pretreatment produce water, and the water yield of pretreatment production water is the 70 weight % that filtering produces water;Pretreatment produces water composition and 2 institute of table Show;High concentration salt water, which returns, participates in above-mentioned second order reaction.
Secondary sludge obtains calcium sulfate, purity 97% through processing.
Through cost accounting, processing cost is about 12 yuan/ton.
Comparative example 1
It is with high salt that coal-burning power plant's desulfurization wastewater (flow 20t/h) with high salt of composition such as table 1 is passed through coal-burning power plant shown in FIG. 1 The system of desulfurization wastewater, in first order reaction unit be added concentration be 10 weight % lime solution, at 25 DEG C, 0.1MPa into The pH of row first order reaction 120min, the first order reaction product that lime solution additional amount makes reach 10.5;
Then first order reaction product is stood and is obtained by filtration level-one sludge and level-one clear water, the composition of level-one clear water As shown in table 2;
It is that adjust pH value be 7 to obtain second order reaction liquid to 15% hydrochloric acid solution by level-one clear water addition concentration, while under being added The weight ratio of the isolated high concentration salt water of free son, second order reaction liquid and high concentration salt water is 1.5:1;
The sodium carbonate liquor that concentration is 8 weight % is added into second order reaction liquid, second level is carried out at 10 DEG C, 0.1MPa 360min is reacted, obtained second order reaction product carries out second level separation of solid and liquid, obtains secondary sludge and second level clear water, sodium carbonate is molten The additional amount of liquid is 12kg/t desulfurization wastewater;
The sodium hypochlorite for the 5 mass ppm that dosage is second level clear water is added into second level clear water, and carries out ultrafiltration (Hang Zhoushui The ultrafiltration apparatus that processing company provides), it obtains filtering and produces water, SDI value is 0.5;
Water being produced to filtering, the hydrogen peroxide that dosage is the 20 mass ppm that filtering produces water being added, dosage is that filtering produces the 10 of water Then quality ppm antisludging agent deactivator pc-191 carries out nanofiltration ion isolation, obtain high concentration salt water and pretreatment produces water;
High concentration salt water, which returns, participates in above-mentioned second order reaction, and the composition that pretreatment produces water is as shown in table 2.
Secondary sludge obtains calcium carbonate through processing.
Through cost accounting, processing cost is about 26.99 yuan/ton.
Comparative example 2
The stone for being 10 weight % to the middle addition concentration of coal-burning power plant's desulfurization wastewater (flow 20t/h) with high salt of composition such as table 1 Grey solution and concentration are the metabisulfite solution of 8 weight %, and reaction 120min is carried out at 25 DEG C, 0.1MPa, and wherein lime is molten The pH for the reaction product that liquid additional amount makes reaches 10.5;By the isolated clear water of reaction product and sludge, metabisulfite solution Additional amount make the hardness of clear water in the range of 10-40mmol/L;
The sodium hypochlorite for the 5 mass ppm that dosage is clear water is added into clear water, and carries out ultrafiltration (GE company provides super Filter equipment), it obtains filtering and produces water, SDI value is 0.5;
Water being produced to filtering, the hydrogen peroxide that dosage is the 20 mass ppm that filtering produces water being added, dosage is that filtering produces the 10 of water Then quality ppm antisludging agent deactivator pc-191 carries out nanofiltration ion isolation, obtain high concentration salt water and pretreatment produces water;
High concentration salt water, which returns, participates in above-mentioned reaction, and the weight ratio of desulfurization wastewater and high concentration salt water is 1.5:1;Pretreatment The composition for producing water is as shown in table 2.
Sludge obtains calcium sulfate, purity 96% through processing.
Through cost accounting, processing cost is about 26.99 yuan/ton.
Table 2
Can be seen that by the result of embodiment, comparative example and table 2 can using the embodiment of method and system of the invention It to effectively realize the separation of divalent and the above ion and monovalent ion, is removed from desulfurization wastewater step by step, ensure that second level dirt Mud can be further processed calcium sulfate (gypsum) byproduct for obtaining high-purity, while pre-processing to produce in water and containing monovalent ion, It can be convenient the purified treatment of subsequent treatment process.And method and system of the invention, take step-by-step processing, substep adding medicine It is mildly operated under lime and sodium sulphate and normal temperature and pressure, the cost of overall operation can substantially reduce.
In comparative example 1-2, although can also have the bivalent ions effect of removing, the calcium sulfate that cannot be obtained or obtain Purity is low, and entire process operation is at high cost.
It is described the prefered embodiments of the present invention in detail above in conjunction with attached drawing, still, the present invention is not limited thereto.At this , can be with various simple variants of the technical solution of the present invention are made in the range of the technology design of invention, including each technical characteristic It is combined with any other suitable method, these simple variants and combination equally should be considered as in disclosed in this invention Hold, all belongs to the scope of protection of the present invention.

Claims (10)

1. a kind of preprocess method of coal-burning power plant's desulfurization wastewater with high salt, comprising:
(1) lime is added to desulfurization wastewater and carries out first order reaction, obtained first order reaction product is separated by solid-liquid separation to obtain through level-one Level-one clear water and level-one sludge;
(2) the level-one clear water is subjected to pH adjusting, obtains the second order reaction liquid that pH value is 6-8;
(3) the second order reaction liquid is subjected to calcium ion removing, wherein the process of the calcium ion removing includes: addition sulfuric acid Then sodium successively carries out the crystal of calcium sulfate separation under second order reaction and room temperature, obtains second level clear water and secondary sludge;
(4) Xiang Suoshu second level clear water is added fungicide and carries out filtering processing, obtains filtering and produces water;
(5) Xiang Suoshu filtering produces water and antisludging agent and antisludging agent deactivator is added and carries out ion isolation, obtain high concentration salt water and Pretreatment produces water;
Wherein, the high concentration salt water is returned and step (3) progress calcium ion removing is added.
2. preprocess method according to claim 1, wherein in step (1), the additional amount of lime makes the first order reaction The pH of product is 10.5-12;
Preferably, the temperature of the first order reaction is 10-30 DEG C, and the pressure of the first order reaction is 0.02-0.1MPa, described one The time of order reaction is 60-180min.
3. preprocess method according to claim 1, wherein in step (3), the additional amount of sodium sulphate makes the second level The total hardness of clear water is 10-40mmol/L.
4. preprocess method according to claim 1, wherein in step (3), the temperature of the second order reaction is 10-30 DEG C, the pressure of the second order reaction is 0.02-0.1MPa, and the time of the second order reaction is 120-360min.
5. preprocess method according to claim 1, wherein in step (4), the fungicide be selected from sodium hypochlorite and/ Or hydrogen peroxide;The additional amount of the fungicide is the 1-20 mass ppm of the second level clear water.
6. preprocess method according to claim 1, wherein in step (4), the filtering processing is ultrafiltration and/or sand Filter;Preferably, it is 1 or less that the filtering, which produces the SDI value of water,.
7. preprocess method according to claim 1, wherein in step (5), the antisludging agent is nanofiltration or reverse osmosis membrane Antisludging agent, the antisludging agent deactivator are selected from ferric trichloride and/or hydrogen peroxide;
Preferably, the additional amount of the antisludging agent is the 1-20 mass ppm that the filtering produces water, and the antisludging agent deactivator adds Entering amount is the 1-20 mass ppm that the filtering produces water.
8. preprocess method according to claim 1, wherein in step (5), the ion isolation is nanofiltration separation;It receives Filtering separation temperature is 10-30 DEG C, and nanofiltration separation pressure is 0.8-1.5MPa, and the water yield that the pretreatment produces water is the filtering Produce the 30-70% of water.
9. preprocess method described in any one of -8 according to claim 1, wherein the second order reaction liquid and described highly concentrated The weight ratio for spending salt water is (1.5-3.5): 1.
10. a kind of system of coal-burning power plant's desulfurization wastewater with high salt, comprising: first order reaction unit (1), acidity adjustment unit (2), two Order reaction unit (3), filtering unit (4) and ion isolation unit (5);
The first order reaction unit is used to that lime to be added to desulfurization wastewater and carries out first order reaction, and isolated level-one clear water and Level-one sludge;
The acidity adjustment unit is used to level-one clear water progress pH being adjusted to second order reaction liquid;
The second order reaction unit is used to that sodium sulphate to be added to the second order reaction liquid and carries out calcium ion removing, and isolated Second level clear water and secondary sludge;
The filtering unit is used to that fungicide to be added to the second level clear water and carries out filtering processing, obtains filtering and produces water;
The ion isolation unit is used to produce water to the filtering and antisludging agent and antisludging agent deactivator is added and carries out ion isolation, It obtains high concentration salt water and pretreatment produces water;
The high salt concentration water out of the ion isolation unit is connected to the entrance of the second order reaction unit, and being used for will be described highly concentrated Degree salt water is passed through the second order reaction unit and carries out the calcium ion removing.
CN201711407552.4A 2017-12-22 2017-12-22 The preprocess method and system of coal-burning power plant's desulfurization wastewater with high salt Pending CN109956579A (en)

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Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS56144792A (en) * 1980-04-15 1981-11-11 Hitachi Plant Eng & Constr Co Ltd Disposal of fluorine-containing waste water
CN102616962A (en) * 2012-03-30 2012-08-01 中国石油化工股份有限公司 Deep stage treatment method for industrial wastewater
CN106882892A (en) * 2017-03-31 2017-06-23 中国神华能源股份有限公司 A kind of processing method of desulfurization wastewater
CN107117758A (en) * 2017-06-05 2017-09-01 南京工大环境科技有限公司 A kind of power plant desulfurization wastewater low consumption Zero discharge treatment method

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS56144792A (en) * 1980-04-15 1981-11-11 Hitachi Plant Eng & Constr Co Ltd Disposal of fluorine-containing waste water
CN102616962A (en) * 2012-03-30 2012-08-01 中国石油化工股份有限公司 Deep stage treatment method for industrial wastewater
CN106882892A (en) * 2017-03-31 2017-06-23 中国神华能源股份有限公司 A kind of processing method of desulfurization wastewater
CN107117758A (en) * 2017-06-05 2017-09-01 南京工大环境科技有限公司 A kind of power plant desulfurization wastewater low consumption Zero discharge treatment method

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Application publication date: 20190702