CN107200436A

CN107200436A - One kind complexing electroplating effluent treatment method, processing system and application

Info

Publication number: CN107200436A
Application number: CN201710446986.9A
Authority: CN
Inventors: 韩全; 张恒
Original assignee: Guangdong Yeanovo Environmental Protection Co Ltd
Current assignee: Guangdong Shangchen Environmental Technology Co ltd
Priority date: 2017-06-14
Filing date: 2017-06-14
Publication date: 2017-09-26
Anticipated expiration: 2037-06-14
Also published as: CN107200436B

Abstract

The present invention provides a kind of complexing electroplating effluent treatment method, it is characterised in that the processing method sequentially includes：(1) complexing electroplating wastewater is pre-processed, obtains pretreated water；(2) pretreated water for obtaining step (1) carries out biochemical treatment, obtains biochemical treatment water；(3) the biochemical treatment water for obtaining step (2) carries out concentration, obtains concentration high salt concentrated water and recycle-water；(4) the concentration high salt concentrated water that step (3) is obtained is evaporated crystallization treatment, obtains recycle-water and crystal；Wherein recycle water standard is：PH 68, electrical conductivity≤50, COD≤30, turbidity≤1；This method is simple to operate, stable, with low cost, treatment effeciency is high, so that the zero-emission or low emission of plating production complexing electroplating wastewater are reached, while realizing the recovery of higher degree to each metal ion in waste water.

Description

One kind complexing electroplating effluent treatment method, processing system and application

Technical field

The present invention relates to a kind of processing method of waste water and processing system, and in particular to a kind of processing of complexing electroplating wastewater Method and its processing system.

Background technology

Electroplating wastewater processing is complexed in handling process often using chemical precipitation method, electrolysis, conventional ion exchange process etc. Processing method.But above-mentioned processing method has some limitations and can not accomplish zero-emission.

Chemical precipitation method is the method that present processing complexing electroplating wastewater is commonly used, and this method needs to add substantial amounts of acid Alkali, while need to add ferrous sulfate, aluminium polychloride, so that the saliferous rate of water discharge is added, and the metal remained in water The discharge of ion is still difficult to reach standard.Therefore, because controlled substance content is extremely low as defined in wastewater discharge standard, row is reached The standard of putting is needed to put into the chemicals of excess, and cost is high, and waste water can not be reclaimed as process water and used.In addition, chemical Sedimentation can not directly be reclaimed to the metal ion in waste water, while will also produce in substantial amounts of sludge, sludge containing big Metal ion is measured, sludge need to be handled again, cause secondary pollution.

The handling process of electrolysis is ripe, stable, but because controlled substance content as defined in discharge standard is extremely low, so Processing method power consumption in electrolysis wastewater is larger, and processing cost is high, and is also easy to produce toxic gas, it is difficult to which processing is arrived up to standard Discharge.

Conventional ion exchange process uses organic backbone ion exchange resin, can effectively remove in waste water it is various be harmful to from Son, while water can be with reuse, but the resin demand required for the processing method is big, and regenerated liquid processing is difficult, need to consume a large amount of Soda acid, processing cost is high；And resin is in regenerative process, because regeneration, the contraction of generation of resin cause tree with expansion A large amount of ruptures of fat, economy is not high.Reverse osmosis membrane concentration electroplating wastewater is such as used, while pure water reuse, but the work Skill is only applied to the waste water system processing of single high valence ion, so using there is its limitation.

As can be seen that there are problems in the various processing methods currently for complexing electroplating wastewater, even if to each electricity The existing equipment of plating factory makes full use of the largely or entirely reuse for being still unable to reach waste water, and to valuable in waste water Value metal can not be effectively separated and reclaim.

The content of the invention

It is an object of the invention to overcome produced problem in the prior art and defect, there is provided a kind of simple to operate, operation The high complexing electroplating effluent treatment method of stable, with low cost, treatment effeciency and corresponding processing system, so as to reach plating life The zero-emission or low emission of production complexing electroplating wastewater, while realizing the recovery of higher degree to each metal ion in waste water, are saved Electroplating industry industrial water amount, substantially reduces pollution of the electroplating industry to environment, reduces the usage amount of soda acid, effectively save can provide Source reduces production cost and realizes the recovery of equipment investment, promotes and promote the cleanly production and sustainable development of electroplating industry Exhibition.

The purpose of the present invention is achieved through the following technical solutions：

The present invention provides a kind of complexing electroplating effluent treatment method, it is characterised in that the processing method sequentially includes：

(1) complexing electroplating wastewater is pre-processed, obtains pretreated water；

(2) pretreated water for obtaining step (1) carries out biochemical treatment, obtains biochemical treatment water；

(3) the biochemical treatment water for obtaining step (2) carries out concentration, obtains concentration high salt concentrated water and reuse Water；

(4) the concentration high salt concentrated water that step (3) is obtained is evaporated crystallization treatment, obtains recycle-water and crystallization Thing；

Wherein recycle water standard is：PH 6-8, electrical conductivity≤50, COD≤30, turbidity≤1.

Preferably, in the step (1),

The complexing electroplating wastewater pH 2-6, it contains copper, nickel, SS and COD；

Preferably, the step of pretreatment is：

(1-1) introduces contact break pond by electroplating wastewater is complexed, and it is 2-3 that sulfuric acid is added in contact break pond to pH, and time chlorine is added afterwards Sour sodium to ORP value is 300-400mv；

Waste water after step (1-1) processing is introduced pH regulating reservoirs by (1-2), and addition sodium hydroxide to pH is 10-11；

Waste water after step (1-2) processing is introduced chemical reaction pond by (1-3), adds coagulant, flocculant is added afterwards, is stirred Mix 20-30min；

Waste water after step (1-3) processing is introduced accurate control High-rate sedimentation system by (1-4)；

Preferably, in the step (1-1), it is 10% sulfuric acid solution regulation pH to add concentration；Preferably, concentration is added ORP value is adjusted for 10% liquor natrii hypochloritis；

Preferably, in the step (1-2), it is 10% sodium hydroxide solution regulation pH to add concentration；

Preferably, in the step (1-3), the coagulant is inorganic coagulant, more preferably FeCl₃；Preferably, institute Flocculant is stated for organic flocculant, more preferably PAM；Preferably, the time interval added between coagulant and flocculant For 20-40min；

Preferably, the wastewater pH handled through step (1-3) is 8-9；

Preferably, in the step (1-4), the accurate control High-rate sedimentation system by water distribution system, precipitation process pond, Inclined tube, effluent weir, sludge bucket are sequentially connected composition；Preferably, the waste water after step (1-3) processing is introduced into the water distribution successively System, precipitation process pond, inclined tube；Supernatant after above-mentioned processing obtains pretreated water into effluent weir, and obtained sludge sinks Enter sludge bucket；Preferably, the pressure in the precipitation process pond is 2-3Mpa.

Preferably, in the step (2), the biochemical treatment step is：The pretreated water that step (1) is obtained enters successively Enter anaerobic pond, Aerobic Pond, membrane bioreactor；

Preferably, anaerobic bacteria is included in the anaerobic pond；Preferably, the anaerobic bacteria is selected from saccharomycete, nitrate bacterium, shuttle One or more in bacillus or bacteroid；

Preferably, the saccharomycete, nitrate bacterium, Fusobacterium or bacteroid make it have salt tolerance through domestication；

Preferably, aerobic microbiological is included in the Aerobic Pond；

Preferably, one or more of the oxygen animalcule in bacillus, rhizobium, nitrifier or mould；

Preferably, the bacillus, rhizobium, nitrifier or mould make it have salt tolerance through domestication；

Preferably, the membrane bioreactor is made up of hollow fiber film assembly and membrane cisterna；

Preferably, the hollow fiber film assembly is located in the membrane cisterna；

Preferably, the doughnut membrane aperture is 0.01-0.1 μm；

Preferably, pH is 6-8 after the biochemical treatment.

Preferably, in the step (3), the concentration step is：The biochemical treatment water that step (2) is obtained is successively By one-level nanofiltration system, first-stage reverse osmosis system, two-stage reverse osmosis system；

Preferably, the one-level nanofiltration system is sequentially connected and constituted by accurate filter and one-level NF membrane；

Preferably, the filter core of the accurate filter is fusion-jet type PP cottons；

Preferably, the filter core aperture of the precise microfiltration device is 5 μm；

Preferably, the one-level NF membrane is technical grade equipment with high desalinization NF membrane；

Preferably, the aperture of the one-level NF membrane is 1-2nm；

Preferably, the one-level NF membrane is 50-70% to the rejection of sodium ion；

Preferably, the rejection ＞ 97% of the one-level NF membrane heavy metal ion and salinity；

Preferably, the film pressure of entering of the one-level nanofiltration system is 1.0-1.5Mpa；

Preferably, the relative molecular mass retention scope of the one-level nanofiltration system is 150-300 dalton；

Preferably, the pH of the water of the entrance one-level nanofiltration system is 6-8；

Preferably, the permeate of the one-level nanofiltration system can be used as recycle-water；

Preferably, the concentrate of the one-level nanofiltration system enters first-stage reverse osmosis system.

Preferably, in the step (3), the first-stage reverse osmosis system by accurate filter and first-stage reverse osmosis film successively Connection composition；

Preferably, the first-stage reverse osmosis film is bitter reverse osmosis membrane；

Preferably, the rejection ＞ 98% of the first-stage reverse osmosis film heavy metal ion and salinity；

Preferably, the aperture of the first-stage reverse osmosis film is 0.1-1nm；

Preferably, the film pressure of entering of the first-stage reverse osmosis system is 1.8Mpa；

Preferably, the pH of the water of the entrance first-stage reverse osmosis system is 5-6；

Preferably, pH is adjusted by adding hydrochloric acid in the first-stage reverse osmosis system；

Preferably, the salt acid for adjusting pH that concentration is 0.2-0.5% is added；

Preferably, the permeate of the first-stage reverse osmosis system returns to one-level nanofiltration system；

Preferably, the concentrate of the first-stage reverse osmosis system enters two-stage reverse osmosis system.

Preferably, in the step (3), the two-stage reverse osmosis system by accurate filter and two-pass reverse osmosis film successively Connection composition；

Preferably, the two-pass reverse osmosis film is seawater reverse osmosis membrane；

Preferably, the rejection ＞ 99.5% of the two-pass reverse osmosis film heavy metal ion and salinity；

Preferably, the aperture of the two-pass reverse osmosis film is 0.1-1nm；

Preferably, the film pressure of entering of the two-stage reverse osmosis system is 4-5Mpa；

Preferably, the pH of the water of the entrance two-stage reverse osmosis system is 6-8；

Preferably, pH is adjusted by adding hydrochloric acid in the two-stage reverse osmosis system；

Preferably, the concentration of the hydrochloric acid is 0.2-0.5%；

Preferably, the permeate of the two-stage reverse osmosis system returns to one-level nanofiltration system；

Preferably, the concentrate of the two-stage reverse osmosis system is the high salt concentrated water.

Preferably, in the step (4), the evaporative crystallization process step is：The high salt concentrated water that step (3) is obtained according to Secondary process heat exchanger, concentration evaporator, crystallizing evaporator；

Preferably, the operation temperature of the heat exchanger is 80-100 DEG C；

Preferably, the operating pressure of the heat exchanger is 0.05-0.1MPa；

Preferably, the concentration evaporator is sequentially connected group by heating chamber, separation chamber, circular chamber, liquid distributor, demister Into；

Preferably, the crystallizing evaporator is sequentially connected and constituted by separation chamber, salt leg, thickener, crystallization kettle；

Preferably, condensed water of the high salt concentrated water after concentration evaporator returns to the two-stage reverse osmosis system；

Preferably, the high salt concentrated water obtains concentrating high salt concentrated water after concentration evaporator；

Preferably, the salt content of the concentration high salt concentrated water is 30-35%；

Preferably, the concentration high salt concentrated water obtains crystal and condensed water after crystallizing evaporator；Preferably, it is described Crystal is sodium sulphate and/or sodium chloride；Preferably, the condensed water is used as recycle-water.

The present invention also provides a kind of processing system of zinc-containing water processing method of the present invention, it is characterised in that described System includes pretreatment unit, biochemical treatment unit, concentration unit and the evaporative crystallization processing unit being sequentially communicated.

Preferably, the pretreatment unit includes the broken zinc pond being sequentially communicated, pH regulating reservoirs, chemical reaction pond, accurate control High-rate sedimentation system processed；The accurate control High-rate sedimentation system is by water distribution system, precipitation process pond, inclined tube, effluent weir, sludge Bucket is sequentially connected composition.

Preferably, the biochemical treatment unit includes anaerobic pond, Aerobic Pond, the membrane bioreactor being sequentially communicated；

Preferably, the doughnut membrane aperture is 0.01-0.1 μm.

Preferably, the concentration unit include be sequentially communicated one-level nanofiltration system, first-stage reverse osmosis system, two grades Counter-infiltration system.

Preferably, the filter core aperture of the accurate filter is 5 μm；

The one-level NF membrane is technical grade equipment with high desalinization NF membrane；

Preferably, the aperture of the one-level NF membrane is 1-2nm；

Preferably, the one-level NF membrane is 50-70% to the rejection of sodium ion；Preferably, the one-level NF membrane The rejection ＞ 97% of heavy metal ion and salinity；

Preferably, the pH of the water of the entrance one-level nanofiltration system is 6-8.

Preferably, the first-stage reverse osmosis system is sequentially connected and constituted by accurate filter and first-stage reverse osmosis film；

Preferably, the filter core aperture of the accurate filter is 5 μm；

Preferably, the aperture of the first-stage reverse osmosis film is 0.1-1nm；

Preferably, the concentration of the hydrochloric acid is 0.2-0.5%.

Preferably, the two-stage reverse osmosis system is sequentially connected and constituted by accurate filter and two-pass reverse osmosis film；

Preferably, the filter core aperture of the accurate filter is 5 μm；

Preferably, the aperture of the two-pass reverse osmosis film is 0.1-1nm；

Preferably, the concentration of the hydrochloric acid is 0.2-0.5%.

Preferably, the evaporative crystallization unit includes heat exchanger, concentration evaporator, the crystallizing evaporator being sequentially communicated；

Preferably, the operation temperature of the heat exchanger is 80-100 DEG C；

Preferably, the operating pressure of the heat exchanger is 0.05-0.1MPa；

Preferably, the crystallizing evaporator is sequentially connected and constituted by separation chamber, salt leg, thickener, crystallization kettle.

Complexing electroplating effluent treatment method of the present invention or complexing electroplating effluent treatment method processing system of the present invention The application united in processing complexing electroplating wastewater.

The present invention for overcome in the prior art complexing electroplating wastewater processing present in defect there is provided complexing electroplating wastewater Processing method be：

Complexing electroplating wastewater pollutant sources analysis of the present invention：Complexing waste water is mainly in electroplating process using complexing The workshop section that metal is electroplated, mainly constitutes plating solution by mantoquita and phosphate, with nickel sulfate, nickel acetate etc. for main salt, secondary phosphorous Hydrochlorate, sodium borohydride, borine, hydrazine etc. are reducing agent, then add various auxiliary agents, reducing agent, potassium pyrophosphate, potassium citrate, ammonia three Acetic acid, additive etc.；The material compositions such as copper, nickel, SS and COD are mainly contained in waste water.

Complexing electroplating effluent treatment method of the present invention and processing system are by the way that " effluent segregation, classification processing, waste water are returned With, resource reclaim " technology path, it is dense using the high-precision removal technology of heavy metal, high salinity wastewater biochemical technology, special membrane The fully recovering after processing, in production, is realized useless by electroplated heavy metals zinc-containing water for contracting technology and mechanical negative pressure evaporation crystallization technique Water zero discharge, 99.67% is brought up to by wastewater recycle rate, and recycling for water resource is realized to greatest extent, by waste water Pollutant be converted into solid recycling, thoroughly realize the zero-emission of waste water.

Complexing electroplating wastewater pretreating process of the present invention：

The complexing electroplating wastewater needs specific aim to remove the phosphorus in waste water, makes the PO in water₄ ^3-Generate difficulty soluble salt to remove, lead to Frequently with coagulant be lime, aluminium salt and molysite.This programme using oxidant carry out contact break, by the hypophosphites in waste water, Metaphosphate, oxidation of phosphite are into orthophosphates.

Complexing electroplating wastewater is collected separately to being complexed after electroplating wastewater regulating reservoir, full and uniform water quality and quantity, by waste water Contact break pond is introduced, sulfuric acid is added in contact break pond to pH 2-3, rear sodium hypochlorite to the ORP value that adds is 300-400mv；After will be upper State the waste water after processing and introduce pH regulating reservoirs, addition sodium hydroxide to pH is 10-11；Waste water is introduced into chemical reaction pond again, plus Enter coagulant, flocculant is added afterwards, stir 20-30min；The coagulant is FeCl₃；The flocculant is PAM, the addition Time interval between coagulant and flocculant is 20-40min；Accurate control High-rate sedimentation system is introduced afterwards；Preferably, it is described Precision control High-rate sedimentation system is sequentially connected and constituted by water distribution system, precipitation process pond, inclined tube, effluent weir, sludge bucket；Will place Waste water after reason introduces the water distribution system, sedimentation basin processing pond, inclined tube successively；Supernatant after above-mentioned processing enters water outlet Weir obtains pretreated water, and sludge sinks to sludge bucket；Above-mentioned accurate control High-rate sedimentation system shortens heavy to increase desilting area The shallow lake time, deposition efficiency is improved, acted on by waterpower water distribution, high-efficiency sedimentation of accurate control High-rate sedimentation system etc., efficiently Flco and SS are precipitated, while in setting the inclined tube in pond, the interference for making jetsam not influenceed by current stabilization reaches rapid precipitation Effect, the disposal ability of the accurate control High-rate sedimentation system is bigger than general sedimentation basin 3-7 times, and the sludge of bottom of pond is by setting The static pressure mud discharging device put is discharged into sludge-tank and further concentrated, and is then pumped into sludge filter press press filtration, and mud cake is located again according to property Reason, can remove about 80% suspension, 40-70% oils, and make delivery turbidity<30NTU, COD decline 40-60% etc.；

Complexing electroplating wastewater biochemical processing process of the present invention：Pretreated water is sequentially entered into anaerobic pond, Aerobic Pond, film Bioreactor；By A/O/MBR biodegradation, the material such as most COD, ammonia nitrogen and SS in waste water is removed；This The anaerobic technique is invented under without dissolved oxygen conditions or under anoxia condition, using the effect of anaerobic bacteria, organic matter is occurred water Solution, acidifying, remove the organic matter in waste water, improve the biodegradability of sewage, are conducive to follow-up aerobic treatment process；The present invention The aerobic process is organic matter oxidation Decomposition in the presence of aerobic microbiological under aerobic conditions, and organic concentration declines, Microbial biomass increase, the organic matter in sewage is attracted to activated sludge and biofilm surface first, and with microbial cell table Face is contacted, and the organic matter of small molecule can be directed through cell membrane into microbial body, and larger molecular organicses then must be It is hydrolyzed to after small molecule be taken in cell body by microorganism again in the presence of exoenzyme-hydrolase.Organic matter is finally divided Solution is into CO₂And H₂O；Membrane bioreactor of the present invention is made up of hollow fiber film assembly and membrane cisterna；Preferably, it is described hollow Fiber film component is located in the membrane cisterna；Membrane module is positioned in membrane cisterna, is aerated in pond, because hollow-fibre membrane is less than Zoogloea and free bacteria, all can be retained in membrane cisterna by 0.1 micron of aperture, so that mud-water separation is reached, it is various outstanding Floating particles, bacterium, algae, turbidity and organic matter are effectively removed, it is ensured that go out aqueous suspension close to zero it is excellent go out Water water quality.The efficient crown_interception of membrane bioreactor, can be smoothed out nitration reaction, effectively with effectively catching nitrifier Remove ammonia nitrogen；The larger molecular organicses for being difficult to degraded can be retained simultaneously, are extended its residence time in biochemical reaction tank, are made Decomposed to greatest extent.

Complexing electroplating wastewater concentration technique of the present invention：By biochemical treatment water sequentially pass through one-level nanofiltration system, First-stage reverse osmosis system, two-stage reverse osmosis system；The present invention is realizes the zero-emission of complexing electroplating wastewater, in biochemical treatment system Rear end sets concentrating and treating system, for handling the strong brine of biochemical treatment system generation；Concentrating and treating system of the present invention The technique combined for multistage concentration, nanofiltration/reverse osmosis concentration, by the concentration step by step of film, make the water of high content of salt waste water by Gradually reduction (the high salt concentrated water salt content obtained is 40-60g/L) is so as to reduce investment and the fortune of subsequent evaporation crystal system Row expense；The concentration technique to need strong brine to be processed in follow-up evaporation and crystallization system, at conventional concentration Reason system reduces 80%, makes the cost of investment of whole Waste Water Treatment and reduces 20-30%, the operating cost of wastewater treatment 30-40% is reduced, the automaticity of system is improved.

Complexing electroplating wastewater evaporative crystallization handling process of the present invention：The high salt concentrated water that concentration is obtained is passed through successively Cross heat exchanger, concentration evaporator, crystallizing evaporator；The present invention accomplishes fully recovering after wastewater treatment to evaporative crystallization stage It is complexed the zero-emission of electroplating wastewater；Waste water is introduced into the heat exchanger in the evaporation and crystallization system, by heat exchange, is removed useless O in water₂And CO₂Gas, the waste water after heat exchange, which enters in concentration evaporator, is evaporated concentration, when waste water salt concentration to 30- When 35% before sodium sulphate and sodium chloride crystallization is produced, the waste water is delivered into crystallizing evaporator, crystal and condensation is obtained Water, condensed water is used as recycle-water.Evaporation and crystallization system of the present invention causes waste water evaporation part using mechanical temperature raising device The negative pressure divided, can save the energy, and the waste steam through overcompression heats supercharging and entered outside the pipe of concentration evaporator, latent heat Pipe is passed to, itself condenses into condensed water, while the brine waste evaporation in pipe.Evaporation and crystallization system of the present invention Feature is small volume, is taken up an area less, energy consumption is low, and the thermal efficiency is high, and the power consumption of general one ton of waste water is 16-20kwh, and its thermal efficiency is 27 times of single-action flash system, are 7 times of quadruple effect flash system, are current state-of-the-art evaporation concentration systems, produced by it Crystal can be through handling or sending relevant departments' purification to utilize, and its main component is sodium sulphate and sodium chloride.

The advantage of above-mentioned evaporation and crystallization system is as follows：(1) system makes identical water tonnage device of making using mixed journey feedwater Ton water power consumes more external technique and reduces 40-50%；(2) it is dense by the high salt of concentrating and treating system because the system mixes journey feedwater Water sequentially enters low temperature effect from the high temperature effect of evaporation and crystallization system, and concentration is gradually risen, and temperature is gradually reduced.Avoid external work In skill, imitated from low temperature to being raised caused by high temperature effect make-up cooling water in high temperature effect feed water concentration, be effectively reduced the knot of high temperature effect Dirt and corrosion condition；(3) it is evenly distributed by the high salt concentrated water of concentrating and treating system on concentration evaporator, it is to avoid existing steaming Send out the uneven susceptible to plugging shortcoming of spray nozzle type feedwater in crystal system；(4) vacuum system uses differential pressure air extractor, accurate between each effect Really form design pressure difference so that the system run all right is reliable.

The processing system of complexing electroplating effluent treatment method of the present invention, using programmable logic controller (PLC), while real Now electric and instrument automatic control and monitoring, using industrial computer, operation process state and operational factor to system are monitored. In addition, the membranous system in the system periodically uses permeate to rinse to rinse the pollutant of film surface, diaphragm；And set up online Chemical cleaning system, it is ensured that system is long-term, stably, Effec-tive Function.

At present, there are chemical precipitation technology, biological treatment on being complexed the Technology development of electroplating wastewater in the prior art Technology and membrane separation technique, routine techniques essentially according to " qualified discharge " highway route design, with the present invention compared with exist it is following not Foot：

(1) routine techniques system wastewater recycle rate is 60%, wherein, water resource is not recycled fully, after wastewater treatment Discharge adds the load of surrounding enviroment；

(2) microorganism is to the poor resistance of salinity in routine biochemistry treatment technology, and sludge concentration is generally 3000mg/L, this The sludge concentration of inventive technique mesophytization system is 7000-8000mg/L.

(3) heavy metal ion not yet 100% is removed, and environmental pollution is still present；

(4) concentrated water that film concentration systems are produced need to be handled again, otherwise can cause two layers of pollution；

(5) routine techniques reuse water conductivity is 200-300 μ S/cm, the μ S/ of the technology of the present invention reuse water conductivity≤50 cm。

Complexing electroplating effluent treatment method of the present invention, the beneficial effect of processing system：

(1) condition that complexing electroplating wastewater pretreating process of the present invention reacts according to various heavy metal ion is different, Using online monitoring instruments such as pH, ORP, measuring pump quantitative dosing is automatically controlled, medicament is added and is fully reacted with waste water, and pass through Precision control High-rate sedimentation system carries out separation of solid and liquid processing, and removal of heavy metal ions rate is up to 99.99%.

(2) complexing electroplating wastewater biochemical process of the present invention uses A/O/MBR techniques, and system is by biochemistry pool, membrane module With membrane cisterna composition, activated sludge can be all retained in membrane cisterna, the various pollutions such as various suspended particulates, bacterium, organic matter The thing residence time is long, so as to be sufficiently removed, it is ensured that effluent quality is excellent, SS is almost nil.This process volume load is high, right Water quality and quantity adaptive faculty is strong, using through taming the extraordinary microorganism with salt tolerant to salt content height and being given up containing difficult degradation COD Water removal efficiency is high, and denitrification effect is good.

(3) complexing electroplating wastewater concentration technology of the present invention using special membrane concentration technique by the salinity in waste water according to The technology that desalination and concentration and smart desalination and concentration are combined is by more than 30 times of Waste water concentrating, and the production water of advanced treatment system can direct reuse In production.Special membrane concentration technique still with efficient salt rejection rate, with higher mechanical strength and uses the longevity under with high flow rate Life, good, the characteristics of cost performance is high of waving function, chemical stability can be being issued compared with low operating pressure.

(4) complexing electroplating wastewater evaporative crystallization of the present invention is using the extraordinary both vapor compression technology of Germany, by distillation hydro-thermal Exchanger, concentration evaporator, crystallizer and centrifuge etc. are constituted, when evaporator handles waste water, the heat energy needed for evaporating waste water Release heat energy is provided when steam condenses and condenses water cooling again, and in the process of running, the loss without latent heat realizes waste water Low-temperature negative-pressure evaporates.In compressor compresses, pressure and temperature is lifted, and high enthalpy steam can fully reclaim steaming as thermal source again Distilled water and dope heat, save energy consumption.Evaporated during evaporation using pipe is outer, not only never incrustation in efficiency high and pipe.

Brief description of the drawings

Hereinafter, embodiment of the present invention is described in detail with reference to accompanying drawing, wherein：

Fig. 1 is complexing electroplating waste water treatment system schematic diagram of the present invention.

Embodiment

Illustrate the present invention referring to specific embodiment.It will be appreciated by those skilled in the art that these embodiments are only For illustrating the present invention, it does not limit the scope of the present invention in any way.

Experimental method in following embodiments, is conventional method unless otherwise specified.Original used in following embodiments Material, reagent material etc., unless otherwise specified, are commercially available products.

First, complexing electroplating wastewater pollutant sources analysis of the present invention：Complexing waste water, which is mainly in electroplating process, to be used The workshop section that complexing metal is electroplated, mainly constitutes plating solution by mantoquita and phosphate, secondary with nickel sulfate, nickel acetate etc. for main salt Phosphite, sodium borohydride, borine, hydrazine etc. be reducing agent, then add various auxiliary agents, reducing agent, potassium pyrophosphate, potassium citrate, Nitrilotriacetic acid, additive etc.；The material compositions such as copper, nickel, SS and COD are mainly contained in waste water.

2nd, complexing electroplating wastewater pretreating process of the present invention：Complexing electroplating wastewater is collected separately to complexing plating After wastewater equalization pond, full and uniform water quality and quantity, waste water is introduced into contact break pond, is added in contact break pond and adds sulphur in contact break pond Acid is to pH 2-3, and rear sodium hypochlorite to the ORP value that adds is 300-400mv；The waste water after above-mentioned processing is introduced into pH regulating reservoirs afterwards, Add sodium hydroxide to pH be 10-11；Waste water is introduced into chemical reaction pond again, coagulant is added, flocculant is added afterwards, is stirred 20-30min；The coagulant is FeCl₃；The flocculant is PAM, between the time between the addition coagulant and flocculant It is divided into 20-40min；Accurate control High-rate sedimentation system is introduced afterwards；Preferably, the accurate control High-rate sedimentation system is by water distribution System, precipitation process pond, inclined tube, effluent weir, sludge bucket are sequentially connected composition；Waste water after processing is introduced into the water distribution successively System, precipitation process pond, inclined tube；Supernatant after above-mentioned processing obtains pretreated water into effluent weir, and sludge sinks to sludge Bucket；Above-mentioned accurate control High-rate sedimentation system shortens the sedimentation time, improves deposition efficiency, pass through essence to increase desilting area The effects such as waterpower water distribution, the high-efficiency sedimentation of close control High-rate sedimentation system, efficient precipitation flco and SS, while in setting in pond The inclined tube, the interference for making jetsam not influenceed by current stabilization reaches rapid precipitation effect, the accurate control High-rate sedimentation system The disposal ability of system is bigger than general sedimentation basin 3-7 times, and the sludge of bottom of pond is discharged into sludge-tank by the static pressure mud discharging device of setting Further concentration, is then pumped into sludge filter press press filtration, mud cake is reprocessed according to property, can remove about 80% suspension, 40- 70% oils, and make delivery turbidity<30NTU, COD decline 40-60% etc.；

3rd, complexing electroplating wastewater biochemical processing process of the present invention：Pretreated water is sequentially entered into anaerobic pond, it is aerobic Pond, membrane bioreactor；By A/O/MBR biodegradation, the thing such as most COD, ammonia nitrogen and SS in waste water is removed Matter；Anaerobic technique of the present invention, using the effect of anaerobic bacteria, sends out organic matter under without dissolved oxygen conditions or under anoxia condition Unboiled water solution, acidifying, remove the organic matter in waste water, improve the biodegradability of sewage, are conducive to follow-up aerobic treatment process；This It is organic matter oxidation Decomposition in the presence of aerobic microbiological, organic concentration under aerobic conditions to invent the aerobic process Decline, microbial biomass increase, the organic matter in sewage is attracted to activated sludge and biofilm surface, and and microorganism first Cell surface is contacted, and the organic matter of small molecule can be directed through cell membrane and enter in microbial body, and larger molecular organicses are then It must be hydrolyzed to after small molecule be taken in cell body by microorganism again in the presence of exoenzyme-hydrolase.Organic matter is most CO is broken down into eventually₂And H₂O；Membrane bioreactor of the present invention is made up of hollow fiber film assembly and membrane cisterna；Preferably, institute Hollow fiber film assembly is stated in the membrane cisterna；Membrane module is positioned in membrane cisterna, is aerated in pond, due to doughnut Film is less than 0.1 micron of aperture, can all be retained in zoogloea and free bacteria in membrane cisterna, so that mud-water separation is reached, Various suspended particulates, bacterium, algae, turbidity and organic matter are effectively removed, it is ensured that go out aqueous suspension close to zero Excellent effluent quality.The efficient crown_interception of membrane bioreactor, can be such that nitration reaction smoothly enters with effectively catching nitrifier OK, ammonia nitrogen is effectively removed；The larger molecular organicses for being difficult to degraded can be retained simultaneously, extend its stop in biochemical reaction tank Time, it is allowed to be decomposed to greatest extent.

4th, complexing electroplating wastewater concentration technique of the present invention：Biochemical treatment water is sequentially passed through into one-level nanofiltration system System, first-stage reverse osmosis system, two-stage reverse osmosis system；The present invention is realizes the zero-emission of complexing electroplating wastewater, in biochemical treatment System Back-end sets concentrating and treating system, for handling the strong brine of biochemical treatment system generation；Concentration of the present invention The technique that system combines for multistage concentration, nanofiltration/reverse osmosis concentration, by the concentration step by step of film, makes the water of high content of salt waste water Amount gradually reduces (the high salt concentrated water salt content obtained is 40-60g/L) to reduce the investment of subsequent evaporation crystal system And operating cost；The concentration technique to need strong brine to be processed in follow-up evaporation and crystallization system, denseer than routine Contracting processing system reduces 80%, makes the cost of investment of whole Waste Water Treatment and reduces 20-30%, the operation of wastewater treatment Cost reduces 30-40%, improves the automaticity of system.

5th, complexing electroplating wastewater evaporative crystallization handling process of the present invention：The high salt concentrated water that concentration is obtained according to Secondary process heat exchanger, concentration evaporator, crystallizing evaporator；The present invention by fully recovering after wastewater treatment to evaporative crystallization stage, Accomplish the zero-emission of complexing electroplating wastewater；Waste water is introduced into the heat exchanger in the evaporation and crystallization system, by heat exchange, is removed Fall the O in waste water₂And CO₂Gas, the waste water after heat exchange, which enters in concentration evaporator, is evaporated concentration, when waste water salt concentration To during 30-35% produce sodium sulphate and sodium chloride crystallization before, the waste water is delivered into crystallizing evaporator, obtain crystal and Condensed water, condensed water is used as recycle-water.Evaporation and crystallization system of the present invention causes waste water to steam using mechanical temperature raising device The negative pressure of part is sent out, the energy can be saved, and the waste steam through overcompression heats supercharging and entered outside the pipe of concentration evaporator, Latent heat passes to pipe, and itself condenses into condensed water, while the brine waste evaporation in pipe.Evaporative crystallization system of the present invention The characteristics of system is small volume, is taken up an area less, energy consumption is low, and the thermal efficiency is high, and the power consumption of general one ton of waste water is 16-20kwh, its thermal effect Rate is 27 times of single-action flash system, is 7 times of quadruple effect flash system, is current state-of-the-art evaporation concentration system, it is produced Raw crystal can be through handling or sending relevant departments' purification to utilize, and its main component is sodium sulphate and sodium chloride.

The technological process of following examples of the present invention, its basic handling flow is：Electroplating and complexing electroplating wastewater → pretreatment Technique → biochemical processing process → entrance anaerobic pond → entrance Aerobic Pond → membrane bioreactor → supercharging → one-level NF membrane point From → supercharging → first-stage reverse osmosis UF membrane → supercharging → two-pass reverse osmosis UF membrane, high salt concentrated water enters evaporative crystallization after separation System；In evaporation and crystallization system, high salt concentrated water handles the condensed water produced by concentration evaporator, can meet workshop recycle-water Water quality requirement.

Embodiment 1

(1) complexing electroplating wastewater is pre-processed, and obtains pretreated water

Complexing electroplating wastewater is taken first, and the complexing waste water is mainly the work electroplated in electroplating process using complexing metal Section, mainly constitutes plating solution by mantoquita and phosphate, with nickel sulfate, nickel acetate etc. for main salt, hypophosphite, sodium borohydride, boron Alkane, hydrazine etc. are reducing agent, then add various auxiliary agents, reducing agent, potassium pyrophosphate, potassium citrate, nitrilotriacetic acid, additive etc.；It is useless The material compositions such as copper, nickel, SS and COD are mainly contained in water.

Complexing electroplating wastewater is collected separately to being complexed after electroplating wastewater regulating reservoir, full and uniform water quality and quantity, by waste water Contact break pond is introduced, the sulfuric acid solution that addition concentration is 10% in contact break pond to pH 2-3 is rear to add the secondary chlorine that concentration is 10% Acid sodium solution to ORP value is 300-400mv；The waste water after above-mentioned processing is introduced into pH regulating reservoirs afterwards, it is 10% to add concentration Sodium hydroxide solution to pH be 10-11；Waste water is introduced into chemical reaction pond again, coagulant FeCl is added₃, flocculant is added afterwards PAM, stirs 20-30min；The time interval added between coagulant and flocculant is 20-40min；Accurate control is introduced afterwards High-rate sedimentation system processed；Preferably, the accurate control High-rate sedimentation system is by water distribution system, precipitation process pond, inclined tube, water outlet Weir, sludge bucket are sequentially connected composition；Waste water after processing is introduced into the water distribution system, precipitation process pond, inclined tube successively；Through upper State the supernatant after processing and obtain pretreated water into effluent weir, sludge sinks to sludge bucket；Above-mentioned accurate control High-rate sedimentation system System shortens the sedimentation time to increase desilting area, improves deposition efficiency, passes through the waterpower cloth of accurate control High-rate sedimentation system Water, high-efficiency sedimentation etc. are acted on, efficient precipitation flco and SS, while in setting the inclined tube in pond, making jetsam not by steady The interference of influence is flowed, rapid precipitation effect is reached, the disposal ability of the accurate control High-rate sedimentation system is than general precipitation Pond is big 3-7 times, and the sludge of bottom of pond is discharged into sludge-tank by the static pressure mud discharging device of setting and further concentrated, and is then pumped into sludge pressure Filter press filtration, mud cake is reprocessed according to property, can remove about 80% suspension, 40-70% oils, and makes delivery turbidity< 30NTU, COD decline 40-60% etc.；

(2) pretreated water is subjected to biochemical treatment, obtains biochemical treatment water

The pretreated water is sequentially entered into anaerobic pond, Aerobic Pond, membrane bioreactor；Wherein, include and detest in anaerobic pond Aerobic microbiological is included in oxygen bacterium, wherein Aerobic Pond；The oxygen animalcule is selected from bacillus, rhizobium, nitrifier or mould In one or more；The bacillus, rhizobium, nitrifier or mould make it have salt tolerance through domestication；The anaerobism Anaerobic bacteria is included in pond；Preferably, one kind in saccharomycete, nitrate bacterium, Fusobacterium or bacteroid of the anaerobic bacteria or A variety of, the saccharomycete, nitrate bacterium, Fusobacterium or bacteroid make it have salt tolerance through domestication；Enter membrane biological reaction afterwards Device, the membrane bioreactor is made up of hollow-fibre membrane (aperture of hollow-fibre membrane is 0.01-0.1 μm) component and membrane cisterna； Membrane module is positioned in membrane cisterna, is aerated in pond, and pH is 6-8 after the biochemical treatment, can be removed most in waste water The materials such as COD, ammonia nitrogen and SS；Anaerobic technique of the present invention utilizes anaerobic bacteria under without dissolved oxygen conditions or under anoxia condition Effect, organic matter is occurred hydrolysis, acidifying, remove the organic matter in waste water, improve the biodegradability of sewage, be conducive to follow-up Aerobic treatment process；Aerobic process of the present invention is organic matter oxygen in the presence of aerobic microbiological under aerobic conditions Change and decompose, organic concentration declines, microbial biomass increases, the organic matter in sewage is attracted to activated sludge and biology first Film surface, and contacted with microbial cell surface, the organic matter of small molecule can be directed through cell membrane and enter in microbial body, And larger molecular organicses must then be hydrolyzed to after small molecule be taken in carefully by microorganism again in the presence of exoenzyme-hydrolase In cell space.Organic matter is finally broken down into CO₂And H₂O；Membrane bioreactor of the present invention is by hollow fiber film assembly and membrane cisterna Composition, membrane module is positioned in membrane cisterna, is aerated in pond, the aperture due to hollow-fibre membrane less than 0.1 micron, can be by Zoogloea and free bacteria are all retained in membrane cisterna, so that mud-water separation is reached, various suspended particulates, bacterium, algae, turbidity And organic matter is effectively removed, it is ensured that go out aqueous suspension close to zero excellent effluent quality.Membrane bioreactor Efficient crown_interception, can be smoothed out nitration reaction, is effectively removed ammonia nitrogen with effectively catching nitrifier；It can retain simultaneously The larger molecular organicses of degraded are difficult to, extends its residence time in biochemical reaction tank, is allowed to be decomposed to greatest extent.

(3) the biochemical treatment water is subjected to concentration, obtains high salt concentrated water and recycle-water

Biochemical treatment water is sequentially passed through into one-level nanofiltration system, first-stage reverse osmosis system, two-stage reverse osmosis system；Described one Level nanofiltration system is sequentially connected and constituted by accurate filter and one-level NF membrane, and wherein the filter core of accurate filter is fusion-jet type PP Cotton, the aperture of precise microfiltration device is 5 μm, and the aperture of the one-level NF membrane is 1nm, and pending water passes through one-level NF membrane When, the rejection to sodium ion is 50%, and the rejection of heavy metal ion and salinity is 98%；Afterwards by one-level nanofiltration system System, pH is 6-8, enters film pressure for 1.5Mpa；The relative molecular mass retention scope of the one-level nanofiltration system is 300 dalton； The permeate of the one-level nanofiltration system can be continuing with through ion exchange as recycle-water；

Concentrate of the above-mentioned processing water Jing Guo one-level nanofiltration system enters first-stage reverse osmosis system, the first-stage reverse osmosis system System is sequentially connected composition by accurate filter and first-stage reverse osmosis film (bitter reverse osmosis membrane, aperture is 0.1-1nm), and one-level is anti- The film pressure of entering of osmosis system is 1.8Mpa, and it is 5-6 to adjust pH by 0.2% hydrochloric acid, by the first-stage reverse osmosis film, counterweight The rejection of metal ion and salinity is 99%；Permeate of the above-mentioned processing water Jing Guo first-stage reverse osmosis system returns to one-level nanofiltration System, its concentrate enters two-stage reverse osmosis system.The two-stage reverse osmosis system is by accurate filter and two-pass reverse osmosis film (seawater reverse osmosis membrane, aperture is 0.1-1nm) is sequentially connected composition；The film pressure of entering of two-stage reverse osmosis system is 5Mpa, is passed through 0.2% hydrochloric acid adjustment pH is 6-8, by the two-pass reverse osmosis film, and the rejection of heavy metal ion and salinity is 99.9%； Above-mentioned processing water returns to one-level nanofiltration system by the permeate of two-stage reverse osmosis system, and its concentrate is high salt concentrated water, high salt The salt content of concentrated water is 40g/L.

The present invention sets concentrating and treating system to realize the zero-emission of complexing electroplating wastewater in biochemical treatment system rear end, For handling the strong brine of biochemical treatment system generation；Concentrating and treating system of the present invention is multistage concentration, nanofiltration/counter-infiltration The technique combined is concentrated, by the concentration step by step of film, making the water of high content of salt waste water gradually reduces (the high salt concentrated water obtained Salt content is 40g/L) so as to reduce investment and the operating cost of subsequent evaporation crystal system；After the concentration technique causes Strong brine to be processed is needed in continuous evaporation and crystallization system, 80% is reduced than conventional concentrating and treating system, makes whole waste water The cost of investment of processing system reduces 30%, and the operating cost of wastewater treatment reduces 40%, makes the automaticity of system Improve.Above-mentioned complexing electroplating wastewater concentration technique, carries out pre-concentration, by one-level nanofiltration system through one-level nanofiltration system Permeate can be used as recycle-water after ion exchange, and the concentrate of the one-level nanofiltration system enters first-stage reverse osmosis system System；The permeate of the first-stage reverse osmosis system returns to one-level nanofiltration system, and the concentrate of the first-stage reverse osmosis system enters Two-stage reverse osmosis system；The permeate of the two-stage reverse osmosis system returns to one-level nanofiltration system, the two-stage reverse osmosis system Concentrate be the high salt concentrated water.

(4) the high salt concentrated water is evaporated crystallization treatment, obtains recycle-water and crystal

Above-mentioned high salt concentrated water is sequentially passed through into heat exchanger, concentration evaporator, crystallizing evaporator；The operation temperature of the heat exchanger Spend for 80-100 DEG C；The operating pressure of the heat exchanger is 0.05-0.1MPa；The concentration evaporator by heating chamber, separation chamber, Circular chamber, liquid distributor, demister are sequentially connected composition；The crystallizing evaporator by separation chamber, salt leg, thickener, crystallization kettle according to Secondary connection composition；Condensed water of the above-mentioned high salt concentrated water after concentration evaporator returns to above-mentioned two-stage reverse osmosis system；High salt is dense The concentrate that water is obtained after concentration evaporator is concentration high salt concentrated water, and salt content is 40-60g/L；The concentration high salt concentrated water Crystal and condensed water are obtained after crystallizing evaporator；Obtained crystal is sodium sulphate and/or sodium chloride；And condensed water is made Workshop is returned to for recycle-water to be continuing with.

Wherein, the concentration evaporator is made up of the multiple evaporators being serially connected, and (90 DEG C or so) heating of low temperature are steamed Vapour is introduced into the first effect, heats feed liquid therein, feed liquid is produced the almost equivalent evaporation lower than vapor (steam) temperature.The steam of generation The second effect is introduced into as heating steam, makes the feed liquid of the second effect with than the first effect lower temperature evaporation.This process is always Repeat to last effect.The solidifying water of first effect is returned at thermal source, and other each solidifying water of effect are exported after collecting as desalination water, a steaming Vapour is put into, and the water that can evaporate many times comes out.Meanwhile, feed liquid is passed through by the concentration successively of the first effect to most end effect, in most end Effect reaches supersaturation and crystallizes and separate out.It is achieved in the separation of solid and liquid of feed liquid.

The technical parameter of the evaporation and crystallization system processing concentrated water is as follows：

(1) desalination water salt content (TDS) is less than 10ppm

(2) ton desalination water steam consumption quantity=(1/ effect number)/90%t/t

(3) 2~4kwh/t of ton desalination water power consumption

A kind of complexing electroplating effluent treatment method of the present invention not only improves wastewater recycle rate relative to prior art To 99.67%, while processing cost, the metal ion recycling reduced in solid waste yield and waste water can be greatly reduced, thoroughly Realize the zero-emission of waste water.

In a word, specific description of embodiments of the present invention is not intended to limit the present invention for the above, and those skilled in the art can be with It is variously modified or is deformed according to the present invention, without departing from the spirit of the present invention, all should belong to right appended by the present invention will The scope asked.

Claims

1. one kind complexing electroplating effluent treatment method, it is characterised in that the processing method sequentially includes：

(3) the biochemical treatment water for obtaining step (2) carries out concentration, obtains concentration high salt concentrated water and recycle-water；

(4) the concentration high salt concentrated water that step (3) is obtained is evaporated crystallization treatment, obtains recycle-water and crystal；

2. processing method according to claim 1, it is characterised in that in the step (1), the complexing electroplating wastewater pH 2-6, it contains copper, nickel, SS and COD；

Preferably, the step of pretreatment is：

(1-1) will be complexed electroplating wastewater and introduce contact break pond, and it is 2-3 that sulfuric acid is added in contact break pond to pH, and sodium hypochlorite is added afterwards It is 300-400mv to ORP value；

Waste water after step (1-2) processing is introduced chemical reaction pond by (1-3), adds coagulant, flocculant is added afterwards, is stirred 20-30min；

Preferably, in the step (1-1), it is 10% sulfuric acid solution regulation pH to add concentration；Preferably, adding concentration is 10% liquor natrii hypochloritis's regulation ORP value；

Preferably, in the step (1-3), the coagulant is inorganic coagulant, more preferably FeCl₃；Preferably, the wadding Solidifying agent is organic flocculant, more preferably PAM；Preferably, the time interval added between coagulant and flocculant is 20- 40min；

Preferably, the wastewater pH handled through step (1-3) is 8-9；

Preferably, in the step (1-4), the accurate control High-rate sedimentation system is by water distribution system, precipitation process pond, tiltedly Pipe, effluent weir, sludge bucket are sequentially connected composition；Preferably, the waste water after step (1-3) processing is introduced described with water system successively System, precipitation process pond, inclined tube；Supernatant after above-mentioned processing obtains pretreated water into effluent weir, and obtained sludge is sunk to Sludge bucket；Preferably, the pressure in the precipitation process pond is 2-3Mpa.

3. processing method according to claim 1 or 2, it is characterised in that in the step (2), the biochemical treatment step Suddenly it is：The pretreated water that step (1) is obtained sequentially enters anaerobic pond, Aerobic Pond, membrane bioreactor；

Preferably, anaerobic bacteria is included in the anaerobic pond；Preferably, the anaerobic bacteria is selected from saccharomycete, nitrate bacterium, Fusobacterium Or the one or more in bacteroid；

Preferably, aerobic microbiological is included in the Aerobic Pond；

Preferably, the doughnut membrane aperture is 0.01-0.1 μm；

Preferably, pH is 6-8 after the biochemical treatment.

4. processing method according to any one of claim 1 to 3, it is characterised in that described dense in the step (3) Contracting process step is：The biochemical treatment water that step (2) is obtained sequentially passes through one-level nanofiltration system, first-stage reverse osmosis system, two Level counter-infiltration system；

Preferably, the aperture of the one-level NF membrane is 1-2nm；

5. processing method according to any one of claim 1 to 4, it is characterised in that in the step (3), described one Level counter-infiltration system is sequentially connected and constituted by accurate filter and first-stage reverse osmosis film；

Preferably, the aperture of the first-stage reverse osmosis film is 0.1-1nm；

6. processing method according to any one of claim 1 to 5, it is characterised in that in the step (3), described two Level counter-infiltration system is sequentially connected and constituted by accurate filter and two-pass reverse osmosis film；

Preferably, the aperture of the two-pass reverse osmosis film is 0.1-1nm；

Preferably, the concentration of the hydrochloric acid is 0.2-0.5%；

7. processing method according to any one of claim 1 to 6, it is characterised in that in the step (4), described to steam Sending out crystallization treatment step is：The high salt concentrated water that step (3) is obtained sequentially passes through heat exchanger, concentration evaporator, crystallizing evaporator；

Preferably, the operation temperature of the heat exchanger is 80-100 DEG C；

Preferably, the operating pressure of the heat exchanger is 0.05-0.1MPa；

Preferably, the concentration evaporator is sequentially connected by heating chamber, separation chamber, circular chamber, liquid distributor, demister and constituted；

Preferably, the concentration high salt concentrated water obtains crystal and condensed water after crystallizing evaporator；Preferably, the crystallization Thing is sodium sulphate and/or sodium chloride；Preferably, the condensed water is used as recycle-water.

8. the processing system of electroplating effluent treatment method is complexed as any one of claim 1 to 7, it is characterised in that institute State pretreatment unit, biochemical treatment unit, concentration unit and evaporative crystallization processing unit that system includes being sequentially communicated.

9. processing system according to claim 8, it is characterised in that the pretreatment unit includes the broken zinc being sequentially communicated Pond, pH regulating reservoirs, chemical reaction pond, accurate control High-rate sedimentation system；The accurate control High-rate sedimentation system is by with water system System, precipitation process pond, inclined tube, effluent weir, sludge bucket are sequentially connected composition.

10. processing system according to claim 8 or claim 9, it is characterised in that the biochemical treatment unit includes being sequentially communicated Anaerobic pond, Aerobic Pond, membrane bioreactor；

Preferably, the doughnut membrane aperture is 0.01-0.1 μm.

11. the processing system according to any one of claim 8 to 10, it is characterised in that the concentration unit bag Include the one-level nanofiltration system being sequentially communicated, first-stage reverse osmosis system, two-stage reverse osmosis system.

12. the processing system according to any one of claim 8 to 11, it is characterised in that the one-level nanofiltration system by Accurate filter and one-level NF membrane are sequentially connected composition；

Preferably, the filter core aperture of the accurate filter is 5 μm；

Preferably, the aperture of the one-level NF membrane is 1-2nm；

Preferably, the one-level NF membrane is 50-70% to the rejection of sodium ion；Preferably, the one-level NF membrane counterweight The rejection ＞ 97% of metal ion and salinity；

13. the processing system according to any one of claim 8 to 12, it is characterised in that the first-stage reverse osmosis system It is sequentially connected and is constituted by accurate filter and first-stage reverse osmosis film；

Preferably, the filter core aperture of the accurate filter is 5 μm；

Preferably, the aperture of the first-stage reverse osmosis film is 0.1-1nm；

Preferably, the concentration of the hydrochloric acid is 0.2-0.5%.

14. the processing system according to any one of claim 8 to 13, it is characterised in that the two-stage reverse osmosis system It is sequentially connected and is constituted by accurate filter and two-pass reverse osmosis film；

Preferably, the filter core aperture of the accurate filter is 5 μm；

Preferably, the aperture of the two-pass reverse osmosis film is 0.1-1nm；

Preferably, the concentration of the hydrochloric acid is 0.2-0.5%.

15. the processing system according to any one of claim 8 to 14, it is characterised in that the evaporative crystallization unit bag Include the heat exchanger being sequentially communicated, concentration evaporator, crystallizing evaporator；

Preferably, the operation temperature of the heat exchanger is 80-100 DEG C；

Preferably, the operating pressure of the heat exchanger is 0.05-0.1MPa；

16. the processing any one of processing method or claim 8 to 15 as any one of claim 1 to 7 Application of the system in processing complexing electroplating wastewater.