CN115557652A - Recycling treatment system and method for zinc-nickel-containing wastewater - Google Patents

Recycling treatment system and method for zinc-nickel-containing wastewater Download PDF

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CN115557652A
CN115557652A CN202211406519.0A CN202211406519A CN115557652A CN 115557652 A CN115557652 A CN 115557652A CN 202211406519 A CN202211406519 A CN 202211406519A CN 115557652 A CN115557652 A CN 115557652A
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wastewater
tank
zinc
sludge
primary
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CN115557652B (en
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黄慧
陈琦
石驰
黄佳伟
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Baowu Water Technology Co Ltd
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Baowu Water Technology Co Ltd
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    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F9/00—Multistage treatment of water, waste water or sewage
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00—Treatment of water, waste water, or sewage
    • C02F1/001—Processes for the treatment of water whereby the filtration technique is of importance
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00—Treatment of water, waste water, or sewage
    • C02F1/02—Treatment of water, waste water, or sewage by heating
    • C02F1/04—Treatment of water, waste water, or sewage by heating by distillation or evaporation
    • C02F1/041—Treatment of water, waste water, or sewage by heating by distillation or evaporation by means of vapour compression
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00—Treatment of water, waste water, or sewage
    • C02F1/44—Treatment of water, waste water, or sewage by dialysis, osmosis or reverse osmosis
    • C02F1/441—Treatment of water, waste water, or sewage by dialysis, osmosis or reverse osmosis by reverse osmosis
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00—Treatment of water, waste water, or sewage
    • C02F1/44—Treatment of water, waste water, or sewage by dialysis, osmosis or reverse osmosis
    • C02F1/444—Treatment of water, waste water, or sewage by dialysis, osmosis or reverse osmosis by ultrafiltration or microfiltration
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00—Treatment of water, waste water, or sewage
    • C02F1/48—Treatment of water, waste water, or sewage with magnetic or electric fields
    • C02F1/488—Treatment of water, waste water, or sewage with magnetic or electric fields for separation of magnetic materials, e.g. magnetic flocculation
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00—Treatment of water, waste water, or sewage
    • C02F1/52—Treatment of water, waste water, or sewage by flocculation or precipitation of suspended impurities
    • C02F1/5236—Treatment of water, waste water, or sewage by flocculation or precipitation of suspended impurities using inorganic agents
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00—Treatment of water, waste water, or sewage
    • C02F1/52—Treatment of water, waste water, or sewage by flocculation or precipitation of suspended impurities
    • C02F1/54—Treatment of water, waste water, or sewage by flocculation or precipitation of suspended impurities using organic material
    • C02F1/56—Macromolecular compounds
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00—Treatment of water, waste water, or sewage
    • C02F1/66—Treatment of water, waste water, or sewage by neutralisation; pH adjustment
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00—Treatment of water, waste water, or sewage
    • C02F2001/007—Processes including a sedimentation step
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00—Treatment of water, waste water, or sewage
    • C02F1/42—Treatment of water, waste water, or sewage by ion-exchange
    • C02F2001/425—Treatment of water, waste water, or sewage by ion-exchange using cation exchangers
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F2103/00—Nature of the water, waste water, sewage or sludge to be treated
    • C02F2103/16—Nature of the water, waste water, sewage or sludge to be treated from metallurgical processes, i.e. from the production, refining or treatment of metals, e.g. galvanic wastes

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  • Hydrology & Water Resources (AREA)
  • Engineering & Computer Science (AREA)
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  • Water Supply & Treatment (AREA)
  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
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Abstract

The invention discloses a zinc and nickel-containing wastewater recycling treatment system and method, which comprise a wastewater adjusting tank, a primary pH adjusting tank, a primary mixed flocculation tank, a primary high-efficiency sedimentation tank, a secondary pH adjusting tank, a secondary mixed flocculation tank, a secondary high-efficiency sedimentation tank, a sludge storage tank, a plate-and-frame filter press, a multi-medium filter, ultrafiltration, weak acid cation resin, a reverse osmosis device, an MVR evaporation concentration crystallization device and a freezing melting crystallization device. The scheme of the invention can ensure that the quality of the discharged water can reach the water quality index of industrial water, meet the aim of wastewater reuse, and can recover zinc mud and anhydrous sodium sulphate with higher purity. The scheme of the invention has stable treatment effect, high automation degree of equipment and simple and convenient operation.

Description

Recycling treatment system and method for zinc-nickel-containing wastewater
Technical Field
The invention relates to the technical field of water treatment, in particular to a system and a method for recycling zinc-nickel-containing wastewater.
Background
In recent years, the economy of China is rapidly developed, and industrial production enters a vigorous development stage. The economic benefit is created and simultaneously the increasingly intensified environmental problem is accompanied. The wastewater recycling treatment is the necessary way to realize the sustainable development of industrial production and the win-win of economy and environment.
The cold-rolled sheet is subjected to oil removal and acid cleaning and then is treated by an electrolytic process to realize a surface coating. After electroplating, the surface of the cold-rolled plate needs to be cleaned, and the cleaning waste liquid is generally electroplating liquid with lower concentration. The cold rolling zinc-nickel-containing wastewater is electroplating cleaning waste liquid, has relatively fixed components, mainly comprises zinc sulfate and nickel sulfate, and also contains a small amount of pollutants such as iron ions, calcium ions, chloride ions, oils and the like.
The traditional treatment scheme of the cold rolling zinc-nickel-containing wastewater adopts a lime precipitation process, heavy metals of zinc and nickel are changed into hydroxide precipitates, solid-liquid separation is carried out in a sedimentation tank or a tubular microfiltration membrane, sludge is sent into a plate-and-frame filter press for dehydration treatment, and the sludge is treated as hazardous waste. The traditional treatment method has a good effect of removing metal ions, but the adding cost of the medicament is high, ions need to be additionally added into the existing wastewater, the conductivity and hardness of the wastewater are improved, the advanced treatment of the wastewater in the later period is not facilitated, the sludge production amount is large, secondary pollution is caused, and resources are wasted.
In order to realize sustainable development of enterprises and enable resources to be efficiently and circularly utilized, a recycling treatment scheme of cold-rolled zinc-nickel-containing wastewater is urgently needed.
It is noted that the information disclosed in this background section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.
Disclosure of Invention
The invention aims to provide a system and a method for recycling zinc-nickel-containing wastewater, which are used for solving the problems that the traditional treatment scheme of the zinc-nickel-containing wastewater in the prior art is easy to cause secondary pollution and the resource waste is serious.
In order to solve the technical problems, the invention provides a zinc-nickel-containing wastewater recycling treatment system which comprises a wastewater adjusting tank, a primary pH adjusting tank, a primary mixing flocculation tank, a primary efficient sedimentation tank, a secondary pH adjusting tank, a secondary mixing flocculation tank, a secondary efficient sedimentation tank, a sludge storage tank, a plate-and-frame filter press, a final neutralization tank, a multi-media filter, an ultrafiltration device, weak acid cation resin, a reverse osmosis device, an MVR evaporation crystallization device, a freezing melting crystallization device and a miscellaneous salt drying device;
the wastewater adjusting tank is used for receiving wastewater, so that the wastewater is uniformly mixed in the wastewater adjusting tank and is output to the primary pH adjusting tank;
the pH of the wastewater is adjusted to 7.5-8.0 by adding sodium hydroxide into the primary pH adjusting tank to form zinc hydroxide precipitate, and the wastewater is output to the primary mixed flocculation tank;
the primary mixed flocculation tank comprises polyferric oxide and magnetic powder, the wastewater is coagulated with an anionic high molecular flocculant in the primary mixed flocculation tank to form large-particle flocs, and the wastewater is output to the primary high-efficiency sedimentation tank;
the primary high-efficiency sedimentation tank is used for separating solid and liquid of the wastewater, zinc-containing sludge partially reflows to the primary mixed flocculation tank through a reflow sludge pump, part of the zinc-containing sludge is discharged into a shearing machine and a magnetic powder collector through a residual sludge pump, the collected magnetic powder returns to the primary mixed flocculation tank, zinc hydroxide sludge is discharged into a zinc sludge storage tank, and the zinc hydroxide sludge is recycled after being dewatered by a plate and frame filter press and is output to the secondary pH adjustment tank;
the secondary pH adjusting tank is used for adjusting the pH of the wastewater to 9.5-10.0 by adding sodium hydroxide to form nickel hydroxide precipitate and outputting the wastewater to the secondary mixed flocculation tank;
the secondary mixed flocculation tank is used for adding sodium carbonate, adding a small amount of polyferric oxide and PAM according to the condition of floc particles, and outputting the wastewater to the secondary efficient sedimentation tank;
the secondary high-efficiency sedimentation tank is used for carrying out solid-liquid separation on the wastewater, part of the mixed sludge containing nickel and calcium carbonate flows back to the secondary mixed flocculation tank through a return sludge pump, and the wastewater is output to the final neutralization tank;
the sludge storage tank is used for receiving the mixed sludge, and the mixed sludge is dewatered by the plate-and-frame filter press and then transported to an outside for disposal;
the final neutralizing tank is used for adding sulfuric acid, adjusting the pH back to 6.5-7 and outputting to the multi-media filter;
the multi-medium filter and the ultrafiltration device are used for removing small-particle suspended matters, so that the SDI of the effluent is less than or equal to 3;
the weak acid cation resin is used for reducing the content of heavy metals in the wastewater;
the reverse osmosis device is used for reducing and concentrating the wastewater, and the produced water meets the industrial water reuse standard;
the MVR evaporation crystallization device is used for controlling the concentration of the discharged concentrated solution in the evaporation process, discharging the concentrated solution into a thickener, and dehydrating the concentrated solution through a centrifugal machine to obtain anhydrous sodium sulphate;
the freezing and melting crystallization device is used for reducing the amount of the impurity salt, mother liquor of the MVR evaporation crystallization device is sent into the freezing and melting crystallization device, the mother liquor is quickly reduced to minus 5 ℃ to 0 ℃ for crystallization, and sodium sulfate decahydrate solid is obtained after the discharged low-temperature crystal mush is filtered and dehydrated. Discharging sodium sulfate decahydrate into a sodium sulfate dissolving tank, melting and evaporating again, controlling the autolytic concentration to be 35-40% of sodium sulfate solution, and centrifugally dewatering to obtain anhydrous sodium sulfate;
the mixed salt drying device is used for receiving the cold nitre liquid and changing the cold nitre liquid into mixed salt to be transported outside.
Optionally, the bottom of the wastewater adjusting tank is provided with a perforated aeration pipe.
Optionally, the perforated aeration pipe is made of UPVC, perforations of the perforated aeration pipe are arranged in a 45-degree crossing manner with a vertical line downwards, and the aperture is 3mm.
Optionally, 10% sodium hydroxide is used as a pH adjusting agent in the primary pH adjusting tank.
Optionally, the primary mixed flocculation tank is used for adding magnetic powder and a coagulant, the concentration of the magnetic powder in the primary mixed flocculation tank is 8-12g/L, the adding amount of the magnetic powder is 200-500ppm, the coagulant is polyferric, the adding amount is 100-200 ppm, and the primary mixed flocculation tank is used for adding an anionic high-molecular flocculant, wherein the adding amount is 1-3ppm.
Optionally, part of sludge in the primary high-efficiency sedimentation tank flows back to the primary mixed flocculation tank, the amount of the returned sludge is 10-20m & lt 3 & gt/h, the residual sludge is lifted to a shearing machine through a pump, sludge flocs are destroyed and then sent to a magnetic drum recoverer, and magnetic powder is recovered and then returned to the primary mixed flocculation tank.
Optionally, a coagulant is added into the primary mixed flocculation tank, wherein the coagulant is polyferric, and the adding amount is 50-100 ppm. And adding sodium carbonate and an anionic high-molecular flocculant into the primary mixing flocculation tank, determining the adding amount of the sodium carbonate according to the hardness of inlet water, wherein the adding amount of the anionic high-molecular flocculant is 0.1-0.5 ppm.
Optionally, the final neutralization tank is adjusted back by using 10% dilute sulfuric acid, and the pH is controlled to be 6.5-7.
Optionally, the filter material of the multi-media filter is quartz sand and anthracite.
Optionally, the running time of the multi-media filter is 24 hours, the air-water backwashing is performed for 1 time, and the air-water backwashing time is 10-15min.
Optionally, the ultrafiltration device employs external pressure ultrafiltration, dead-end filtration.
Optionally, the running time of the ultrafiltration device is 30min, the air-water backwashing is 1 time, and the air-water backwashing time is 5-6min.
Optionally, after the weak acid cation resin is saturated by adsorption, the weak acid cation resin is regenerated by using 4-5% sulfuric acid and 4-5% sodium hydroxide, and an adsorption solution returns to the wastewater adjusting tank.
Optionally, the reverse osmosis unit employs an anti-fouling reverse osmosis membrane.
Optionally, the MVR evaporative crystallization device adopts waste heat steam to evaporate, and the concentration of the discharged concentrated solution is controlled to be 20-25%.
Optionally, the miscellaneous salt drying device adopts a vacuum rake dryer or a roller dryer, the feed concentration is 25-30%, and the frozen crystallization concentrated cold nitre solution is treated.
Based on the same inventive concept, the invention also provides a zinc-nickel-containing wastewater recycling treatment method, which utilizes the zinc-nickel-containing wastewater recycling treatment system in any one of the above characteristic descriptions, and the zinc-nickel-containing wastewater recycling treatment method comprises the following steps:
the wastewater adjusting tank receives wastewater, so that the wastewater is uniformly mixed in the wastewater adjusting tank and is output to the primary pH adjusting tank;
the pH of the wastewater is adjusted to 7.5-8.0 by adding sodium hydroxide into the primary pH adjusting tank to form zinc hydroxide precipitate, and the wastewater is output to the primary mixed flocculation tank;
the primary mixed flocculation tank comprises polyferric oxide and magnetic powder, the wastewater is coagulated with an anionic high molecular flocculant in the primary mixed flocculation tank to form large granular flocs, and the wastewater is output to the primary high-efficiency sedimentation tank;
the primary high-efficiency sedimentation tank enables the wastewater to be subjected to solid-liquid separation, zinc-containing sludge partially reflows to the primary mixed flocculation tank through a backflow sludge pump, part of the zinc-containing sludge is discharged into a shearing machine and a magnetic powder collector through a residual sludge pump, the collected magnetic powder returns to the primary mixed flocculation tank, zinc hydroxide sludge is discharged into a zinc sludge storage tank, and the zinc hydroxide sludge is recycled after being dewatered by a plate and frame filter press and is output to the secondary pH adjustment tank;
the secondary pH adjusting tank adjusts the pH of the wastewater to 9.5-10.0 by adding sodium hydroxide to form nickel hydroxide precipitate, and the wastewater is output to the secondary mixed flocculation tank;
the secondary mixed flocculation tank is used for adding sodium carbonate, adding a small amount of polyferric oxide and PAM according to the condition of floc particles, and outputting the wastewater to the secondary efficient sedimentation tank;
the secondary high-efficiency sedimentation tank is used for carrying out solid-liquid separation on the wastewater, part of the mixed sludge containing nickel and calcium carbonate flows back to the secondary mixed flocculation tank through a return sludge pump, and the wastewater is output to the final neutralization tank;
the sludge storage tank receives the mixed sludge, and the mixed sludge is dewatered by the plate-and-frame filter press and then transported to an outside for disposal;
adding sulfuric acid into the final neutralizing tank, adjusting the pH back to 6.5-7, and outputting to the multi-media filter;
the multi-medium filter and the ultrafiltration device remove small-particle suspended matters, so that the SDI of the effluent is less than or equal to 3;
the weak acid cation resin is used for reducing the content of heavy metals in the wastewater;
the reverse osmosis device reduces and concentrates the wastewater, and the produced water meets the industrial water reuse standard;
the MVR evaporation crystallization device discharges the discharged concentrated solution into a thickener by controlling the concentration of the discharged concentrated solution in the evaporation process, and dehydrates the concentrated solution through a centrifugal machine to obtain anhydrous sodium sulphate;
the freezing and melting crystallization device reduces the amount of impurity salt, mother liquor of the MVR evaporation crystallization device is sent into the freezing and melting crystallization device, the mother liquor is quickly reduced to minus 5 ℃ to 0 ℃ for crystallization, and sodium sulfate decahydrate solid is obtained after the discharged low-temperature crystal mush is filtered and dehydrated. Discharging sodium sulfate decahydrate into a sodium sulfate dissolving tank, melting and evaporating again, controlling the autolytic concentration to be 35-40% of sodium sulfate solution, and centrifugally dewatering to obtain anhydrous sodium sulfate;
and the miscellaneous salt drying device receives the cold nitre liquid and turns into miscellaneous salt for outward transportation.
Compared with the prior art, the invention has the following beneficial effects:
1. the invention provides a zinc-nickel-containing wastewater recycling treatment system, which has stable treatment effect and simple and convenient operation, ensures that the effluent meets the water quality standard of industrial water, the wastewater is completely recycled, and zinc hydroxide and anhydrous sodium sulphate with higher purity are recycled, thereby realizing the resource utilization of the zinc-nickel-containing wastewater;
2. the invention provides a zinc-nickel-containing wastewater recycling treatment system, which reduces the sludge production as much as possible and reduces the treatment cost of hazardous wastes;
3. the invention provides a zinc-nickel-containing wastewater recycling treatment system, which realizes zero discharge of wastewater, evaporates a small amount of final evaporation mother liquor to form a small amount of miscellaneous salts, and carries out curing treatment.
The zinc-nickel-containing wastewater recycling treatment method provided by the invention and the zinc-nickel-containing wastewater recycling treatment system belong to the same inventive concept, so that the zinc-nickel-containing wastewater recycling treatment method has the same beneficial effects, and the details are not repeated.
Drawings
Fig. 1 is a schematic structural diagram of a recycling treatment system for waste water containing zinc and nickel provided by an embodiment of the invention.
Detailed Description
The following describes in more detail embodiments of the present invention with reference to the schematic drawings. The advantages and features of the present invention will become more apparent from the following description. It is to be noted that the drawings are in a very simplified form and are not to precise scale, which is merely for the purpose of facilitating and distinctly claiming the embodiments of the present invention.
In the description of the present invention, it is to be understood that the terms "center", "upper", "lower", "left", "right", and the like indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience in describing the present invention and simplifying the description, but do not indicate or imply that the device or element referred to must have a specific orientation, be constructed in a specific orientation, and be operated, and thus, should not be construed as limiting the present invention.
Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or to implicitly indicate the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.
Referring to fig. 1, an embodiment of the present invention provides a system for recycling wastewater containing zinc and nickel, including a wastewater adjusting tank, a primary pH adjusting tank, a primary mixed flocculation tank, a primary efficient sedimentation tank, a secondary pH adjusting tank, a secondary mixed flocculation tank, a secondary efficient sedimentation tank, a sludge storage tank, a plate-and-frame filter press, a final neutralization tank, a multi-media filter, an ultrafiltration apparatus, a weak acid cation resin, a reverse osmosis apparatus, an MVR evaporative crystallization apparatus, a freezing and melting crystallization apparatus, and a miscellaneous salt drying apparatus;
the wastewater adjusting tank is used for receiving wastewater, so that the wastewater is uniformly mixed in the wastewater adjusting tank and is output to the primary pH adjusting tank;
the pH of the wastewater is adjusted to 7.5-8.0 by adding sodium hydroxide into the primary pH adjusting tank to form zinc hydroxide precipitate, and the wastewater is output to the primary mixed flocculation tank;
the primary mixed flocculation tank comprises polyferric oxide and magnetic powder, the wastewater is coagulated with an anionic high molecular flocculant in the primary mixed flocculation tank to form large granular flocs, and the wastewater is output to the primary high-efficiency sedimentation tank;
the primary high-efficiency sedimentation tank is used for separating solid and liquid of the wastewater, zinc-containing sludge partially reflows to the primary mixed flocculation tank through a reflow sludge pump, part of the zinc-containing sludge is discharged into a shearing machine and a magnetic powder collector through a residual sludge pump, the collected magnetic powder returns to the primary mixed flocculation tank, zinc hydroxide sludge is discharged into a zinc sludge storage tank, and the zinc hydroxide sludge is recycled after being dewatered by a plate and frame filter press and is output to the secondary pH adjustment tank;
the secondary pH adjusting tank is used for adjusting the pH of the wastewater to 9.5-10.0 by adding sodium hydroxide to form nickel hydroxide precipitate and outputting the wastewater to the secondary mixed flocculation tank;
the secondary mixed flocculation tank is used for adding sodium carbonate, adding a small amount of polyferric oxide and PAM according to the condition of floc particles, and outputting the wastewater to the secondary efficient sedimentation tank;
the secondary high-efficiency sedimentation tank is used for carrying out solid-liquid separation on the wastewater, part of the mixed sludge containing nickel and calcium carbonate flows back to the secondary mixed flocculation tank through a return sludge pump, and the wastewater is output to the final neutralization tank;
the sludge storage tank is used for receiving the mixed sludge, and the mixed sludge is dewatered by the plate-and-frame filter press and then transported to an outside for disposal;
the final neutralizing tank is used for adding sulfuric acid, adjusting the pH back to 6.5-7 and outputting to the multi-media filter;
the multi-medium filter and the ultrafiltration device are used for removing small-particle suspended matters, so that the SDI of the effluent is less than or equal to 3;
the weak acid cation resin is used for reducing the content of heavy metals in the wastewater;
the reverse osmosis device is used for reducing and concentrating the wastewater, and the produced water meets the industrial water reuse standard;
the MVR evaporation crystallization device is used for discharging the discharged concentrated solution into a thickener by controlling the concentration of the discharged concentrated solution in the evaporation process, and dehydrating the discharged concentrated solution through a centrifugal machine to obtain anhydrous sodium sulphate;
the freezing and melting crystallization device is used for reducing the amount of the impurity salt, mother liquor of the MVR evaporation crystallization device is sent into the freezing and melting crystallization device, the mother liquor is quickly reduced to minus 5 ℃ to 0 ℃ for crystallization, and sodium sulfate decahydrate solid is obtained after the discharged low-temperature crystal mush is filtered and dehydrated. Discharging sodium sulfate decahydrate into a sodium sulfate dissolving tank, melting and evaporating again, controlling the autolytic concentration to be 35-40% of sodium sulfate solution, and centrifugally dewatering to obtain anhydrous sodium sulfate;
the mixed salt drying device is used for receiving the cold nitre liquid and changing the cold nitre liquid into mixed salt to be transported outside.
The zinc-nickel-containing wastewater recycling system is characterized by being stable in treatment effect and simple and convenient to operate, so that effluent meets the water quality standard of industrial water, wastewater is recycled completely, and zinc hydroxide and anhydrous sodium sulphate with high purity are recycled, so that the zinc-nickel-containing wastewater is recycled; the production amount of sludge is reduced as much as possible, and the treatment cost of hazardous waste is reduced; the scheme of this application still can realize the waste water zero release, will finally a small amount of evaporation mother liquor evaporate and form a small amount of miscellaneous salt, solidification treatment.
Specifically, in this embodiment, the bottom of the wastewater adjusting tank is provided with a perforated aeration pipe.
Specifically, in this embodiment, the perforated aeration pipe is made of UPVC, and the perforations of the perforated aeration pipe are arranged to intersect the vertical line at an angle of 45 ° downward, and have an aperture of 3mm.
Specifically, in this embodiment, 10% sodium hydroxide is used as the pH adjusting agent in the first-stage pH adjusting tank.
Specifically, in this embodiment, the primary mixed flocculation tank is filled with magnetic powder and a coagulant, the magnetic powder in the primary mixed flocculation tank has a concentration of 8-12g/L, the magnetic powder is filled at 200-500ppm, the coagulant is polyferric, the filling amount is 100-200 ppm, and the primary mixed flocculation tank is filled with an anionic polymeric flocculant at 1-3ppm.
Specifically, in this embodiment, a part of sludge in the first-stage high-efficiency sedimentation tank flows back to the first-stage mixed flocculation tank, the amount of the returned sludge is 10-20m3/h, the residual sludge is lifted to a shearing machine through a pump, sludge flocs are destroyed and then sent to a magnetic drum recoverer, and magnetic powder is recovered and then returned to the first-stage mixed flocculation tank.
Specifically, in this embodiment, a coagulant is added into the first-stage mixing flocculation tank, the coagulant is polyferric, and the addition amount is 50-100 ppm. And adding sodium carbonate and an anionic high-molecular flocculant into the primary mixing flocculation tank, determining the adding amount of the sodium carbonate according to the hardness of inlet water, wherein the adding amount of the anionic high-molecular flocculant is 0.1-0.5 ppm.
Specifically, in this example, the final neutralization tank was adjusted back using 10% dilute sulfuric acid, and the pH was controlled to 6.5-7.
Specifically, in this embodiment, the filter material of the multi-media filter is quartz sand and anthracite.
Optionally, the running time of the multi-media filter is 24 hours, the air-water backwashing is performed for 1 time, and the air-water backwashing time is 10-15min.
Specifically, in this embodiment, the ultrafiltration device employs external pressure type ultrafiltration, dead-end filtration.
Specifically, in the embodiment, the running time of the ultrafiltration device is 30min, the air-water backwashing is performed for 1 time, and the air-water backwashing time is 5-6min.
Specifically, in this embodiment, after the weak acid cation resin is saturated by adsorption, it is regenerated by using 4-5% sulfuric acid and 4-5% sodium hydroxide, and the adsorption solution is returned to the wastewater conditioning tank.
Specifically, in this embodiment, the reverse osmosis apparatus employs an anti-pollution reverse osmosis membrane.
Specifically, in this embodiment, the MVR evaporative crystallization apparatus evaporates using waste heat steam, and controls the concentration of the discharged concentrated solution to 20-25%.
Specifically, in this embodiment, the miscellaneous salt drying device adopts a vacuum rake dryer, the feeding concentration is 25-30%, and the frozen crystallization concentrated cold nitre solution is treated.
Aiming at the water quality characteristics of the cold-rolled zinc-nickel-containing wastewater, the embodiment provides a process system suitable for recycling the zinc-nickel-containing wastewater, the treatment effect of the scheme is stable, the wastewater can be completely recycled, the zinc hydroxide and the anhydrous sodium sulphate with higher purity are recycled, and the zinc-nickel-containing wastewater is recycled. The equipment has high automation operation degree, is simple and convenient to operate and operate, and is suitable for industrial production.
The method comprises the following specific steps:
the parameters of the zinc-nickel containing wastewater are assumed as follows: pH is 1-3, total oil is less than or equal to 3mg/L, suspended matter is less than or equal to 200mg/L, COD is less than or equal to 30mg/L, hardness is less than or equal to 200mg/L, zn 2+ ≤8000mg/L，Ni 2+ ≤100mg/L，SO 4 2- ≤8000mg/L，C l- ≤50mg/L，TDS≤15000mg/L。
The treatment process comprises the following steps: the system comprises a wastewater adjusting tank, a first-stage pH adjusting tank, a first-stage mixing flocculation tank, a first-stage efficient sedimentation tank, a second-stage pH adjusting tank, a second-stage mixing flocculation tank, a second-stage efficient sedimentation tank, a sludge storage tank, a plate-and-frame filter press, a multi-media filter, an ultrafiltration device, weak acid cation resin, a reverse osmosis device, an MVR evaporation crystallization device, a freezing and melting crystallization device and a miscellaneous salt drying device.
(1) A wastewater adjusting tank: the wastewater is discharged into a wastewater adjusting tank, and a perforated aeration pipe is arranged at the bottom of the tank to ensure that the incoming water is uniformly mixed in the adjusting tank; the bottom of the adjusting tank is provided with a perforated aeration pipe which is made of UPVC, the holes are arranged downwards and form 45-degree cross arrangement with the vertical line, and the aperture is 3mm.
(2) Primary neutralization coagulation flocculation: the wastewater is lifted to a first-stage pH adjusting tank, and the pH is adjusted to 7.5-8.0 by adding sodium hydroxide to form zinc hydroxide precipitate. The wastewater automatically flows to a coagulation tank, added with polyferric oxide and magnetic powder, discharged into the flocculation tank and coagulated with an anionic polymeric flocculant (PAM) to form large-particle flocs. 10% sodium hydroxide is used as pH regulating agent, and the pH of the first-stage pH regulating tank is controlled to be 7.5-8.0. And adding magnetic powder and a coagulant into the primary coagulation tank, wherein the concentration of the magnetic powder in the coagulation tank is 8-12g/L, and the adding amount of the magnetic powder is 200-500ppm. The coagulant is polyferric, and the adding amount is 100-200 ppm. And adding an anionic high-molecular flocculant into the flocculation tank, wherein the adding amount is 1-3ppm.
(3) First-stage efficient precipitation: the wastewater automatically flows into a first-level efficient sedimentation tank for solid-liquid separation, the zinc-containing sludge partially flows back into a flocculation tank through a return sludge pump, part of the zinc-containing sludge is discharged into a shearing machine and a magnetic powder collector through a residual sludge pump, and the collected magnetic powder returns to a coagulation tank. And discharging the zinc hydroxide sludge into a zinc sludge storage pool, dehydrating by using a plate-and-frame filter press, and recycling. Part of sludge in the first-stage efficient sedimentation tank flows back to the flocculation tank, and the amount of the returned sludge is generally 10-20m & lt 3 & gt/h; and lifting the residual sludge to a shearing machine through a pump, damaging sludge flocs, sending the sludge flocs to a magnetic drum recoverer, and recovering magnetic powder and returning the sludge flocs to a coagulation tank. The recovery rate of magnetic powder is more than or equal to 95 percent. Zinc hydroxide sludge is discharged into a zinc sludge storage tank, is dehydrated through a plate-and-frame filter press and then is recycled, and zinc sludge cakes can also be sent into a sludge drying device, so that the water content of the sludge is further reduced, and the later-period outward transportation is facilitated.
(4) Secondary neutralization coagulation flocculation: and (3) flowing the supernatant of the first-stage efficient precipitation to a second-stage pH adjusting tank, and adding sodium hydroxide to adjust the pH to 9.5-10.0 to form nickel hydroxide precipitation. The wastewater flows to a mixing flocculation tank automatically, sodium carbonate is added, and a small amount of polyferric oxide and PAM are added according to the condition of floc particles. And automatically flowing into a secondary efficient sedimentation tank for solid-liquid separation. The pH value of the second-stage pH adjusting tank is controlled to be 9.5-10.0. And (3) adding a coagulant into the secondary coagulation tank, wherein the coagulant is polyferric, and the adding amount is 50-100 ppm. Sodium carbonate and anionic high molecular flocculant are added into the flocculation tank. The adding amount of sodium carbonate is determined according to the hardness of inlet water, and the adding amount of the anionic polymeric flocculant is 0.1-0.5 ppm.
(5) Secondary efficient precipitation: effluent from the second-stage neutralization coagulation flocculation tank automatically flows into a second-stage efficient sedimentation tank for solid-liquid separation, and the mixed sludge containing nickel and calcium carbonate partially flows back into the flocculation tank through a return sludge pump, so that the dosage of the medicament is reduced. Discharging the mixed sludge into a mixed sludge storage tank, dehydrating by a plate-and-frame filter press, and transporting outside.
(6) Final neutralization tank: the supernatant from the second-stage high-efficiency precipitation is passed to a final neutralization tank where sulfuric acid is added to adjust the pH back to 6.5-7. And adjusting the pH value of the final neutralization tank to 6.5-7 by using 10% dilute sulfuric acid.
(7) Multi-media filter and ultrafiltration device: the precipitated effluent is lifted to a multi-media filter and an ultrafiltration device through a pump, and small-particle suspended matters are further removed, so that the effluent SDI is less than or equal to 3, and the requirement of reverse osmosis water inflow is met. The filter material of the multi-medium filter is quartz sand and anthracite. The running time is 24h, the air-water backwashing is carried out for 1 time, and the backwashing time is about 10-15min. The ultrafiltration device adopts external pressure type ultrafiltration and dead-end filtration. The running time is 30min, and the air-water backwashing time is about 5-6min after 1 time of backwashing. According to the pollution condition, chemical strengthening cleaning is carried out regularly.
(8) Weak acid cation resin: the ultrafiltration effluent is lifted to a weak acid cation resin device to further reduce the heavy metal content (such as calcium, magnesium, zinc, nickel and the like) in the wastewater. After the weak acid cation resin is adsorbed and saturated, 4-5% sulfuric acid and 4-5% sodium hydroxide are adopted for regeneration, and the adsorption solution returns to a wastewater adjusting tank.
(9) A reverse osmosis device: and a secondary reverse osmosis device is arranged to reduce the amount of the wastewater and concentrate the wastewater, and the produced water meets the industrial water reuse standard. The reverse osmosis device adopts an anti-pollution reverse osmosis membrane, and the concentrated water TDS is concentrated to about 80g/L through secondary reverse osmosis;
(10) MVR evaporative crystallization: the reverse osmosis concentrated water promotes MVR evaporation crystallization system, the concentration (20-25%) of the concentrated solution discharged in the evaporation process is controlled, the concentrated solution is discharged into a thickener, and the anhydrous sodium sulphate is obtained by dewatering through a centrifuge. The condensed water meets the industrial water recycling standard for recycling. MVR evaporation crystallization adopts waste heat steam for evaporation, the concentration of discharged concentrated solution needs to be controlled to be 20-25%, and the centrifugal dehydration condition of anhydrous sodium sulfate is met; the content of chloride in the concentrated mother liquor is controlled to ensure the purity of anhydrous sodium sulphate. When the concentration of sodium chloride exceeds 15-18%, the mother liquor of MVR evaporation crystallization is continuously sent into a freezing crystallization system, rapidly reduced to-5-0 ℃, and dehydrated to form sodium sulfate decahydrate.
(11) Freezing, melting and crystallizing: in order to reduce the amount of impurity salt, mother liquor of MVR evaporation crystallization is continuously sent into a freezing crystallization system and is rapidly reduced to-5-0 ℃ for crystallization. And filtering and dehydrating the discharged low-temperature crystal mush to obtain sodium sulfate decahydrate solid. Discharging the sodium sulfate decahydrate into a sodium sulfate dissolving tank, melting and evaporating again, controlling the autolytic concentration to be (35-40%) sodium sulfate solution, and centrifugally dehydrating to obtain anhydrous sodium sulfate. Sending the cold nitre solution into a miscellaneous salt drying device to be changed into miscellaneous salt for outward transportation. The condensed water meets the industrial water recycling standard for recycling. The miscellaneous salt drying device adopts a vacuum rake dryer, the feeding concentration is 25-30%, and the frozen crystallization concentrated cold nitre solution is processed.
To facilitate a better understanding of the aspects of the present application by those skilled in the art, a more specific example is provided below:
the parameters of the wastewater containing zinc and nickel are the same as the assumed parameters. Zinc-nickel-containing waste water resourceful treatment system includes: the system comprises a wastewater adjusting tank, a primary pH adjusting tank, a primary mixed flocculation tank, a primary high-efficiency sedimentation tank, a secondary pH adjusting tank, a secondary mixed flocculation tank, a secondary high-efficiency sedimentation tank, a sludge storage tank, a plate-and-frame filter press, a multi-media filter, an ultrafiltration device, weak acid cation resin, a reverse osmosis device, an MVR evaporative crystallization device, a freezing and melting crystallization device and a miscellaneous salt drying device.
The pH value of the primary neutralization is 7.5-8, the polyferric oxide and magnetic powder are added into the primary coagulation tank, and the mixture is discharged into the flocculation tank to be coagulated with an anionic high molecular flocculant (PAM) to form large-particle flocs and form zinc hydroxide precipitate. The pH value of the secondary neutralization is 9.5-10, the polyferric is added into a secondary coagulation tank, and the sodium carbonate and the anionic high molecular flocculant are added into a secondary flocculation tank to form nickel hydroxide and calcium carbonate precipitates.
And discharging sludge in the first-stage high-efficiency sedimentation tank into a shearing machine and a magnetic powder collector, and returning the collected magnetic powder to the coagulation tank. The recovery rate of magnetic powder is more than or equal to 95 percent. And (3) discharging the zinc hydroxide sludge into a zinc sludge storage tank, dehydrating by using a plate-and-frame filter press, wherein the water content of the sludge cake is less than or equal to 70%, and in order to reduce the water content of the sludge, the sludge cake can be sent into a sludge drying device, so that the water content is less than or equal to 30%, and the transportation and the recycling are convenient. The sludge in the secondary efficient sedimentation tank is mixed sludge, the main components of which are nickel hydroxide and calcium carbonate, and the mixed sludge is transported outside after being dehydrated by a plate-and-frame filter press. The plate-and-frame filter presses of two kinds of different sludge are separately arranged, so that the purity of the zinc hydroxide sludge is ensured, and the recycling value is improved. Through analysis and detection, the zinc oxide content of the zinc hydroxide sludge after dehydration treatment is 75-85%, and the rest main impurities are ferric oxide and silicon dioxide (magnetic powder content).
The ultrafiltration device of the embodiment adopts external pressure type ultrafiltration, and the turbidity of the inlet water is preferably less than or equal to 5NTU, so that the front end adopts a multi-medium filter and a self-cleaning filter to intercept larger particle suspended matters. If submerged ultrafiltration is used, the front-end pretreatment can be relaxed appropriately.
The weak acid cation resin bed can adopt a fixed bed or a floating bed, the weak acid cation resin bed of the embodiment adopts a floating bed, and the designed filtration speed is less than or equal to 25-28m/h. In the regeneration process, 4-5% of sulfuric acid, 4-5% of sodium hydroxide and softened water are adopted for regeneration. Firstly, sulfuric acid is adopted for regeneration, and the regeneration flow rate is 2.3-2.5m/h; then water washing is adopted, and the flow rate of the water washing is 3-3.2m/h; sodium hydroxide is adopted for transformation, and the regeneration flow rate is 2.3-2.5m/h; finally, water washing is adopted, and the flow rate of the water washing is 3-3.2m/h.
The reverse osmosis device adopts an anti-pollution reverse osmosis membrane, the first-stage reverse osmosis is low-pressure reverse osmosis, the recovery rate is 60-70%, and concentrated water is concentrated to 35-40g/L; the second-stage reverse osmosis is high-pressure reverse osmosis, the recovery rate is 60-70%, and the TDS of the concentrated water is concentrated to 80-10g/L. The low-pressure reverse osmosis produced water and the high-pressure reverse osmosis produced water are mixed to be used as industrial reuse water, and the water quality meets the design specification of industrial circulating cooling water treatment (GB/T50050-2017).
The evaporative crystallization process section can select multi-effect evaporation under the condition of residual heat steam, thereby reducing the operation cost. In the embodiment, residual heat steam resources are not used, and a mechanical compression evaporative crystallization process (MVR evaporative crystallization) is adopted. The concentration and temperature of the materials must be controlled during the operation process, thereby ensuring the purity of the anhydrous sodium sulphate. The quality of the anhydrous sodium sulphate can meet the standard of class II first-class products in the standard table 1 of GB/T6009-2014 'Industrial anhydrous sodium sulphate'.
Finally, the frozen, crystallized, concentrated and cold nitre solution passes through a vacuum rake dryer to be transported out as miscellaneous salt.
Based on the same inventive concept, the invention also provides a zinc-nickel-containing wastewater recycling method, which utilizes the zinc-nickel-containing wastewater recycling system in any one of the above characteristic descriptions, and the zinc-nickel-containing wastewater recycling method comprises the following steps:
the wastewater adjusting tank receives wastewater, so that the wastewater is uniformly mixed in the wastewater adjusting tank and is output to the primary pH adjusting tank;
the pH of the wastewater is adjusted to 7.5-8.0 by adding sodium hydroxide into the primary pH adjusting tank to form zinc hydroxide precipitate, and the wastewater is output to the primary mixed flocculation tank;
the primary mixed flocculation tank comprises polyferric oxide and magnetic powder, the wastewater is coagulated with an anionic high molecular flocculant in the primary mixed flocculation tank to form large granular flocs, and the wastewater is output to the primary high-efficiency sedimentation tank;
the primary high-efficiency sedimentation tank enables the wastewater to be subjected to solid-liquid separation, zinc-containing sludge partially reflows to the primary mixed flocculation tank through a backflow sludge pump, part of the zinc-containing sludge is discharged into a shearing machine and a magnetic powder collector through a residual sludge pump, the collected magnetic powder returns to the primary mixed flocculation tank, zinc hydroxide sludge is discharged into a zinc sludge storage tank, and the zinc hydroxide sludge is recycled after being dewatered by a plate and frame filter press and is output to the secondary pH adjustment tank;
the secondary pH adjusting tank adjusts the pH of the wastewater to 9.5-10.0 by adding sodium hydroxide to form nickel hydroxide precipitate, and the wastewater is output to the secondary mixed flocculation tank;
the secondary mixed flocculation tank is used for adding sodium carbonate, adding a small amount of polyferric oxide and PAM according to the condition of floc particles, and outputting the wastewater to the secondary efficient sedimentation tank;
the secondary high-efficiency sedimentation tank carries out solid-liquid separation on the wastewater, the mixed sludge containing nickel and calcium carbonate partially reflows to the secondary mixed flocculation tank through a reflowing sludge pump, and the wastewater is output to the final neutralization tank;
the sludge storage tank receives the mixed sludge, and the mixed sludge is dewatered by the plate-and-frame filter press and then transported to an outside for disposal;
adding sulfuric acid into the final neutralization tank, adjusting the pH back to 6.5-7, and outputting to the multi-media filter;
the multi-medium filter and the ultrafiltration device remove small-particle suspended matters, so that the SDI of the effluent is less than or equal to 3;
the weak acid cation resin is used for reducing the content of heavy metals in the wastewater;
the reverse osmosis device reduces and concentrates the wastewater, and the produced water meets the industrial water reuse standard;
the MVR evaporation crystallization device discharges the discharged concentrated solution into a thickener by controlling the concentration of the discharged concentrated solution in the evaporation process, and dehydrates the concentrated solution through a centrifugal machine to obtain anhydrous sodium sulphate;
the freezing and melting crystallization device reduces the amount of impurity salt, mother liquor of the MVR evaporation crystallization device is sent into the freezing and melting crystallization device, the mother liquor is quickly reduced to minus 5 ℃ to 0 ℃ for crystallization, and sodium sulfate decahydrate solid is obtained after the discharged low-temperature crystal mush is filtered and dehydrated. Discharging sodium sulfate decahydrate into a sodium sulfate dissolving tank, melting and evaporating again, controlling the autolytic concentration to be 35-40% of sodium sulfate solution, and centrifugally dewatering to obtain anhydrous sodium sulfate;
and the miscellaneous salt drying device receives the cold nitre liquid and turns into miscellaneous salt for outward transportation.
Compared with the prior art, the invention has the following beneficial effects:
1. the invention provides a zinc-nickel-containing wastewater recycling treatment system, which has stable treatment effect and simple and convenient operation, ensures that the effluent meets the water quality standard of industrial water, the wastewater is completely recycled, and zinc hydroxide and anhydrous sodium sulphate with higher purity are recycled, thereby realizing the resource utilization of the zinc-nickel-containing wastewater;
2. the invention provides a zinc-nickel-containing wastewater recycling treatment system, which reduces the sludge production as much as possible and reduces the treatment cost of hazardous wastes;
3. the invention provides a zinc-nickel-containing wastewater recycling treatment system, which realizes zero discharge of wastewater, evaporates a small amount of evaporated mother liquor to form a small amount of miscellaneous salts and carries out curing treatment.
The zinc-nickel-containing wastewater recycling treatment method provided by the invention and the zinc-nickel-containing wastewater recycling treatment system belong to the same invention concept, so that the zinc-nickel-containing wastewater recycling treatment method has the same beneficial effects, and the details are not repeated.
In the description herein, references to the description of "one embodiment," "some embodiments," "an example" or "a specific example" or the like are intended to mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. And the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments. Furthermore, various embodiments or examples described in this specification can be combined and combined by those skilled in the art.
The above description is only a preferred embodiment of the present invention, and does not limit the present invention in any way. It will be understood by those skilled in the art that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims (17)

1. A zinc-nickel-containing wastewater recycling treatment system is characterized by comprising a wastewater adjusting tank, a primary pH adjusting tank, a primary mixed flocculation tank, a primary high-efficiency sedimentation tank, a secondary pH adjusting tank, a secondary mixed flocculation tank, a secondary high-efficiency sedimentation tank, a sludge storage tank, a plate-and-frame filter press, a final neutralization tank, a multi-medium filter, an ultrafiltration device, a weak acid cation resin, a reverse osmosis device, an MVR evaporation crystallization device, a freezing and melting crystallization device and a mixed salt drying device;
the waste water adjusting tank is used for receiving waste water, so that the waste water is uniformly mixed in the waste water adjusting tank and is output to the primary pH adjusting tank;
the pH of the wastewater is adjusted to 7.5-8.0 by adding sodium hydroxide into the primary pH adjusting tank to form zinc hydroxide precipitate, and the wastewater is output to the primary mixed flocculation tank;
the primary mixed flocculation tank comprises polyferric oxide and magnetic powder, the wastewater is coagulated with an anionic high molecular flocculant in the primary mixed flocculation tank to form large-particle flocs, and the wastewater is output to the primary high-efficiency sedimentation tank;
the primary high-efficiency sedimentation tank is used for separating solid and liquid of the wastewater, zinc-containing sludge partially reflows to the primary mixed flocculation tank through a reflow sludge pump, part of the zinc-containing sludge is discharged into a shearing machine and a magnetic powder collector through a residual sludge pump, the collected magnetic powder returns to the primary mixed flocculation tank, zinc hydroxide sludge is discharged into a zinc sludge storage tank, and the zinc hydroxide sludge is recycled after being dewatered by a plate and frame filter press and is output to the secondary pH adjustment tank;
the secondary pH adjusting tank is used for adjusting the pH of the wastewater to 9.5-10.0 by adding sodium hydroxide to form nickel hydroxide precipitate and outputting the wastewater to the secondary mixed flocculation tank;
the secondary mixed flocculation tank is used for adding sodium carbonate, adding a small amount of polyferric oxide and PAM (polyacrylamide) according to the condition of floc particles, and outputting the wastewater to the secondary efficient sedimentation tank;
the secondary high-efficiency sedimentation tank is used for carrying out solid-liquid separation on the wastewater, part of the mixed sludge containing nickel and calcium carbonate flows back to the secondary mixed flocculation tank through a return sludge pump, and the wastewater is output to the final neutralization tank;
the mixed sludge storage tank is used for receiving mixed sludge, and the mixed sludge is dewatered by the plate-and-frame filter press and then transported to an outside for disposal;
the final neutralizing tank is used for adding sulfuric acid, adjusting the pH back to 6.5-7 and outputting to the multi-media filter;
the multi-medium filter and the ultrafiltration device are used for removing small-particle suspended matters, so that the SDI of the effluent is less than or equal to 3;
the weak acid cation resin is used for reducing the content of heavy metals in the wastewater;
the reverse osmosis device is used for reducing and concentrating the wastewater, and the produced water meets the industrial water reuse standard;
the MVR evaporation crystallization device is used for controlling the concentration of the discharged concentrated solution in the evaporation process, discharging the concentrated solution into a thickener, and dehydrating the concentrated solution through a centrifugal machine to obtain anhydrous sodium sulphate;
the freezing and melting crystallization device is used for reducing the amount of the impurity salt, mother liquor of the MVR evaporation crystallization device is sent into the freezing and melting crystallization device, the mother liquor is quickly reduced to minus 5 ℃ to 0 ℃ for crystallization, and sodium sulfate decahydrate solid is obtained after the discharged low-temperature crystal mush is filtered and dehydrated. Discharging sodium sulfate decahydrate into a sodium sulfate dissolving tank, melting and evaporating again, controlling the autolytic concentration to be 35-40% sodium sulfate solution, and centrifugally dewatering to obtain anhydrous sodium sulfate;
the mixed salt drying device is used for receiving the cold nitre liquid and changing the cold nitre liquid into mixed salt to be transported outside.
2. The recycling system for wastewater containing zinc and nickel according to claim 1, characterized in that the bottom of the wastewater adjusting tank is provided with a perforated aeration pipe.
3. The recycling treatment system for wastewater containing nickel and zinc according to claim 2, wherein the perforated aeration pipe is made of UPVC, the perforations of the perforated aeration pipe are arranged in a 45-degree crossing manner with the vertical line downwards, and the aperture is 3mm.
4. The recycling treatment system for wastewater containing nickel and zinc according to claim 1, wherein 10% sodium hydroxide is used as a pH adjusting agent in the first-stage pH adjusting tank.
5. The recycling treatment system for wastewater containing zinc and nickel according to claim 1, characterized in that magnetic powder and coagulant are added into the primary mixing flocculation tank, the concentration of the magnetic powder in the primary mixing flocculation tank is 8-12g/L, the addition amount of the magnetic powder is 200-500ppm, the coagulant is polyferric, the addition amount is 100-200 ppm, and the addition amount of anionic polymeric flocculant into the primary flocculation tank is 1-3ppm.
6. The recycling treatment system for wastewater containing zinc and nickel according to claim 1, wherein part of sludge in the primary high-efficiency sedimentation tank flows back to the primary mixed flocculation tank, the amount of the returned sludge is 10-20m3/h, the residual sludge is lifted to a shearing machine through a pump, sludge flocs are destroyed and then sent to a magnetic drum recoverer, and magnetic powder is recovered and then returned to the primary mixed flocculation tank.
7. The recycling treatment system for wastewater containing zinc and nickel according to claim 1, wherein the coagulant is added into the primary mixing flocculation tank, the coagulant is polyferric, and the adding amount is 50-100 ppm. And adding sodium carbonate and an anionic high-molecular flocculant into the primary mixing flocculation tank, determining the adding amount of the sodium carbonate according to the hardness of inlet water, wherein the adding amount of the anionic high-molecular flocculant is 0.1-0.5 ppm.
8. The recycling treatment system for waste water containing zinc and nickel according to claim 1, characterized in that the final neutralization tank is adjusted back by 10% dilute sulfuric acid, and the pH is controlled to 6.5-7.
9. The recycling treatment system for waste water containing zinc and nickel according to claim 1, wherein the filter material of the multi-media filter is quartz sand and anthracite.
10. The recycling treatment system for wastewater containing nickel and zinc according to claim 9, wherein the operation time of the multi-media filter is 24 hours, the air-water backwashing is performed for 1 time, and the air-water backwashing time is 10-15min.
11. The recycling treatment system for wastewater containing zinc and nickel according to claim 1, wherein the ultrafiltration device adopts external pressure type ultrafiltration and dead-end filtration.
12. The recycling treatment system for wastewater containing zinc and nickel according to claim 1, wherein the running time of the ultrafiltration device is 30min, the air-water backwashing is performed for 1 time, and the air-water backwashing time is 5-6min.
13. The recycling treatment system for wastewater containing zinc and nickel according to claim 1, wherein the weak acid cation resin is regenerated by using 4-5% sulfuric acid and 4-5% sodium hydroxide after being saturated by adsorption, and the adsorption solution returns to the wastewater adjusting tank.
14. The recycling treatment system for wastewater containing zinc and nickel according to claim 1, characterized in that the reverse osmosis device adopts an anti-pollution reverse osmosis membrane.
15. The recycling treatment system for waste water containing zinc and nickel according to claim 1, wherein the MVR evaporation crystallization device adopts waste heat steam to evaporate, and the concentration of the discharged concentrated solution is controlled to be 20-25%.
16. The recycling treatment system for wastewater containing zinc and nickel according to claim 1, wherein the miscellaneous salt drying device adopts a vacuum rake dryer or a roller dryer, the feed concentration is 25-30%, and the frozen crystalline concentrated cold nitrate solution is treated.
17. A zinc-nickel-containing wastewater recycling method, characterized in that, by using the zinc-nickel-containing wastewater recycling system according to any one of claims 1 to 16, the zinc-nickel-containing wastewater recycling method comprises:
the wastewater adjusting tank receives wastewater, so that the wastewater is uniformly mixed in the wastewater adjusting tank and is output to the primary pH adjusting tank;
the pH of the wastewater is adjusted to 7.5-8.0 by adding sodium hydroxide into the primary pH adjusting tank to form zinc hydroxide precipitate, and the wastewater is output to the primary mixed flocculation tank;
the primary mixed flocculation tank comprises polyferric oxide and magnetic powder, the wastewater is coagulated with an anionic high molecular flocculant in the primary mixed flocculation tank to form large granular flocs, and the wastewater is output to the primary high-efficiency sedimentation tank;
the primary high-efficiency sedimentation tank enables the wastewater to be subjected to solid-liquid separation, zinc-containing sludge partially reflows to the primary mixed flocculation tank through a reflowing sludge pump, part of the zinc-containing sludge is discharged into a shearing machine and a magnetic powder collector through a residual sludge pump, the collected magnetic powder returns to the primary mixed flocculation tank, zinc hydroxide sludge is discharged into a zinc sludge storage tank, the zinc hydroxide sludge is dehydrated through a plate and frame filter press and then recycled, and the wastewater is output to the secondary pH adjustment tank;
the secondary pH adjusting tank adjusts the pH of the wastewater to 9.5-10.0 by adding sodium hydroxide to form nickel hydroxide precipitate, and the wastewater is output to the secondary mixed flocculation tank;
the secondary mixed flocculation tank is used for adding sodium carbonate, adding a small amount of polyferric oxide and PAM according to the condition of floc particles, and outputting the wastewater to the secondary efficient sedimentation tank;
the secondary high-efficiency sedimentation tank is used for carrying out solid-liquid separation on the wastewater, part of the mixed sludge containing nickel and calcium carbonate flows back to the secondary mixed flocculation tank through a return sludge pump, and the wastewater is output to the final neutralization tank;
the sludge storage tank receives the mixed sludge, and the mixed sludge is dewatered by the plate-and-frame filter press and then transported to an outside for disposal;
adding sulfuric acid into the final neutralizing tank, adjusting the pH back to 6.5-7, and outputting to the multi-media filter;
the multi-medium filter and the ultrafiltration device remove small-particle suspended matters, so that the SDI of the effluent is less than or equal to 3;
the weak acid cation resin is used for reducing the content of heavy metals in the wastewater;
the reverse osmosis device reduces and concentrates the wastewater, and the produced water meets the industrial water reuse standard;
the MVR evaporative crystallization device is discharged into a thickener by controlling the concentration of a discharged concentrated solution in the evaporation process, and is dehydrated by a centrifugal machine to obtain anhydrous sodium sulphate;
the freezing and melting crystallization device reduces the amount of the impurity salt, the mother liquor of the MVR evaporation crystallization device is fed into the freezing and melting crystallization device, the mother liquor is rapidly reduced to minus 5 ℃ to 0 ℃ for crystallization, and sodium sulfate decahydrate solid is obtained after the discharged low-temperature crystal mush is filtered and dehydrated. Discharging sodium sulfate decahydrate into a sodium sulfate dissolving tank, melting and evaporating again, controlling the autolytic concentration to be 35-40% of sodium sulfate solution, and centrifugally dewatering to obtain anhydrous sodium sulfate;
and the miscellaneous salt drying device receives the cold nitre liquid and turns into miscellaneous salt for outward transportation.
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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN116621387A (en) * 2023-06-30 2023-08-22 青岛水务集团有限公司 Concentrated solution full-quantification treatment system and method

Citations (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1437523A (en) * 1973-03-29 1976-05-26 Kayaba Industry Co Ltd Method for the recycle treatment of waste water from nickel plating
KR20000000456A (en) * 1999-10-25 2000-01-15 지은상 System of treated for industrial wastewater
JP2005232517A (en) * 2004-02-18 2005-09-02 Astec Irie Co Ltd Method for recycling electroless nickel plating waste solution
JP2005238181A (en) * 2004-02-27 2005-09-08 Nippon Steel Corp Method for treating wastewater to recover valuable metal and plating solution manufacturing method
CN104310651A (en) * 2014-10-28 2015-01-28 温玉友 Oily stainless steel cold-rolled wastewater treatment device and method
CN104787864A (en) * 2015-03-30 2015-07-22 湖南科技大学 Preparation method of composite decoloring flocculant for printing and dyeing wastewater treatment
CN105016569A (en) * 2014-04-25 2015-11-04 宝山钢铁股份有限公司 Processing system and method for cold rolling reverse osmosis strong brine
CN106116005A (en) * 2016-08-19 2016-11-16 天津美能科技有限公司 The process for reclaiming of electroplating wastewater and equipment thereof
CN108033523A (en) * 2017-12-21 2018-05-15 江南大学 A kind of electric flocculation handles the technique containing zinc-nickel complex compound electroplating wastewater
CN109775899A (en) * 2019-03-25 2019-05-21 南通科闻智能科技有限公司 The recovery method of nickel in a kind of stainless steel acid cleaning waste water
CN110921751A (en) * 2018-09-19 2020-03-27 宝山钢铁股份有限公司 Treatment method and system for removing total zinc and total organic carbon in cold rolling zinc-containing wastewater
CN111392962A (en) * 2020-03-23 2020-07-10 东莞道汇环保科技股份有限公司 Treatment equipment and process for zinc-nickel alloy electroplating wastewater
CN112645530A (en) * 2021-02-03 2021-04-13 湖南惟创环境科技有限公司 Pretreatment device and process flow for zinc-containing nickel-containing electroplating wastewater
CN113816526A (en) * 2021-09-18 2021-12-21 武汉钢铁有限公司 Water quenching water recycling treatment process for cold rolling continuous annealing unit
CN218811188U (en) * 2022-11-10 2023-04-07 宝武水务科技有限公司 Zinc-nickel-containing wastewater recycling treatment system

Patent Citations (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1437523A (en) * 1973-03-29 1976-05-26 Kayaba Industry Co Ltd Method for the recycle treatment of waste water from nickel plating
KR20000000456A (en) * 1999-10-25 2000-01-15 지은상 System of treated for industrial wastewater
JP2005232517A (en) * 2004-02-18 2005-09-02 Astec Irie Co Ltd Method for recycling electroless nickel plating waste solution
JP2005238181A (en) * 2004-02-27 2005-09-08 Nippon Steel Corp Method for treating wastewater to recover valuable metal and plating solution manufacturing method
CN105016569A (en) * 2014-04-25 2015-11-04 宝山钢铁股份有限公司 Processing system and method for cold rolling reverse osmosis strong brine
CN104310651A (en) * 2014-10-28 2015-01-28 温玉友 Oily stainless steel cold-rolled wastewater treatment device and method
CN104787864A (en) * 2015-03-30 2015-07-22 湖南科技大学 Preparation method of composite decoloring flocculant for printing and dyeing wastewater treatment
CN106116005A (en) * 2016-08-19 2016-11-16 天津美能科技有限公司 The process for reclaiming of electroplating wastewater and equipment thereof
CN108033523A (en) * 2017-12-21 2018-05-15 江南大学 A kind of electric flocculation handles the technique containing zinc-nickel complex compound electroplating wastewater
CN110921751A (en) * 2018-09-19 2020-03-27 宝山钢铁股份有限公司 Treatment method and system for removing total zinc and total organic carbon in cold rolling zinc-containing wastewater
CN109775899A (en) * 2019-03-25 2019-05-21 南通科闻智能科技有限公司 The recovery method of nickel in a kind of stainless steel acid cleaning waste water
CN111392962A (en) * 2020-03-23 2020-07-10 东莞道汇环保科技股份有限公司 Treatment equipment and process for zinc-nickel alloy electroplating wastewater
CN112645530A (en) * 2021-02-03 2021-04-13 湖南惟创环境科技有限公司 Pretreatment device and process flow for zinc-containing nickel-containing electroplating wastewater
CN113816526A (en) * 2021-09-18 2021-12-21 武汉钢铁有限公司 Water quenching water recycling treatment process for cold rolling continuous annealing unit
CN218811188U (en) * 2022-11-10 2023-04-07 宝武水务科技有限公司 Zinc-nickel-containing wastewater recycling treatment system

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
FUKUTA等: "SULFURATION TREATMENT OF ELECTROPLATING WASTEWATER FOR SELECTIVE RECOVERY OF COPPER, ZINC AND NICKEL RESOURCE", GLOBAL NEST JOURNAL, vol. 8, no. 2, 31 December 2006 (2006-12-31), pages 131 - 136 *
张鹤鸣: "宝钢冷轧电镀锌废水处理", 工业用水与废水, vol. 31, no. 3, 31 December 2000 (2000-12-31), pages 25 - 27 *

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN116621387A (en) * 2023-06-30 2023-08-22 青岛水务集团有限公司 Concentrated solution full-quantification treatment system and method
CN116621387B (en) * 2023-06-30 2023-11-14 青岛水务集团有限公司 Concentrated solution full-quantification treatment system and method

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