CN103243348B - Method and equipment for recovering heavy metals in electroplating wastewater - Google Patents

Abstract

The invention discloses a method and equipment for recovering heavy metals in electroplating wastewater, belonging to the technical field of electroplating wastewater treatment. The method comprises the following steps: (1) treating the electroplating wastewater with an ion exchange resin, so that the heavy metal ions in the electroplating wastewater are adsorbed on the ion exchange resin; (2) using a regeneration agent to elute the heavy metal ions adsorbed on the ion exchange resin, Obtain regeneration solution; (3) Electrolyze the regeneration solution by using swirl electrolysis technology to precipitate heavy metals on the negative electrode. The equipment includes a resin exchange treatment unit and an electrolysis recovery treatment unit, and the electrolysis recovery treatment unit includes a cyclone electrolyzer and a backflow device for controlling the flow rate of the liquid. Through the introduction of swirling flow electrolysis technology, concentration polarization can be avoided, and the elemental metal that is finally electrolyzed is smoother and more selective. Exchange resin regeneration solution can be applied in practical engineering.

Description

Method and equipment for recovering heavy metals in electroplating wastewater

technical field

The invention relates to the technical field of electroplating wastewater treatment, in particular to a method and equipment for recovering heavy metals in electroplating wastewater.

Background technique

The wastewater in the electroplating industry has the characteristics of large water volume, complex composition, serious environmental pollution, and many precious metals and heavy metals. At present, the domestic treatment of this type of wastewater generally adopts general physical and chemical treatment methods, and at the same time, it uses non-standard reflux to the accident pool for further treatment. Discharge after meeting environmental protection requirements. However, this method has the following defects: First, a large amount of chemicals need to be added in the process of physical and chemical treatment, thereby generating a large amount of physical and chemical sludge, which causes secondary pollution to the environment; second, a large amount of precious metals and heavy metals in the electroplating wastewater cannot be recycled. Not only cause environmental pollution, but also have the disadvantage of waste. In response to the above problems, people have carried out research and development, and obtained the technical means of combining ion exchange resin and electrolysis technology, which can better treat electroplating wastewater and recover heavy metals in it at the same time, but these technical means also have some defects to varying degrees , because the electrolysis method will eventually produce concentration polarization, which has the disadvantages of low selectivity, low purity of electrolyzed copper, and not easy to form flakes, many burrs and pinholes, ugly appearance, low current efficiency, and inability to electrolyze low-concentration solutions, etc. , which in turn affects the operation of the entire system. Due to the limitations of these technologies, the electrolytic treatment of the exchange resin regeneration solution still remains in the laboratory stage or the small test and pilot test stages, and is rarely used in actual engineering treatment. Moreover, in the conventional technology, when the combination of ion exchange resin treatment and physical and chemical treatment is adopted, the ion exchange resin treatment process is usually placed after the physical and chemical treatment process, which can ensure the stability of the ion exchange resin and prolong its service life. , and can fully purify the electroplating wastewater to ensure the quality of the effluent.

With the vigorous development of the surface treatment industry, the electroplating industry is particularly important and has the characteristics of rapid development, which makes the treatment of wastewater in the electroplating industry more urgent, and urges people to seek a method that is both environmentally friendly and economical, and can discharge electroplating wastewater up to standard or A treatment method for electroplating wastewater that meets the quality requirements of influent water for reuse.

Contents of the invention

Based on this, the purpose of the present invention is to overcome the defects of the prior art and provide a method for reclaiming heavy metals in electroplating wastewater, which can avoid the generation of concentration polarization and enable the electrolytic treatment of exchange resin regeneration solution to be applied to practical projects middle.

To achieve the above object, the present invention takes the following technical solutions:

A method for reclaiming heavy metals in electroplating wastewater, comprising the following steps:

(1) The electroplating wastewater is treated with ion exchange resin, so that the heavy metal ions in the electroplating wastewater are adsorbed on the ion exchange resin;

(2) Elute the heavy metal ions adsorbed on the ion exchange resin with a regenerant to obtain a regenerated solution;

(3) Using swirl electrolysis technology, control the circulation flow rate to 0.4-0.8m/s, voltage 2-4V, current density 50-200A/M ² , and electrolyze the regeneration solution at 10-30°C to precipitate heavy metals on the negative electrode .

When using the above method to treat electroplating wastewater, firstly, through the principle of ion exchange, the heavy metal cations in the electroplating wastewater are exchanged with the hydrogen ions on the ion exchange resin, and the hydrogen ions enter the solution, while the heavy metal cations are adsorbed on the stationary phase—that is, on the ion exchange resin. , and then eluted with an acidic regenerant, let the hydrogen ions in the eluent elute the heavy metal cations from the stationary phase, and then use swirl electrolysis to electrolyze the heavy metals under the condition of high-speed swirling of the solution , to complete the purpose of recycling heavy metals. The circulating flow rate is in units of the height of the regenerating liquid in the circulating swirling flow electrolyzer per second. When the parameter value is constant, the absolute value of the circulating flow rate is related to the cross-sectional area of the swirling flow electrolyzer used. If the cross-sectional area is small, the circulating flow rate will be absolute. The smaller the value, the larger the cross-sectional area, the larger the absolute value of the circulation flow. Since heavy metal ions in electroplating wastewater are relatively simple, generally mainly copper, nickel, and zinc ions, and copper ions have a large potential difference compared with other metal ions in electroplating wastewater, copper ions are preferentially precipitated at the cathode, so swirl electrolysis is used technology, avoiding the limitation of concentration polarization in the traditional electrolysis process, and high-quality metal products can be electrolyzed through simple swirl electrolysis conditions.

In one of the embodiments, when swirl electrolysis is used, the circulation flow rate is controlled to be 0.4-0.6 m/s, the voltage is 2-3V, the current density is 100-200A/M ² , and the temperature is 15-25°C.

In one embodiment, the ion exchange resin is a copper-specific adsorption resin. For example, the hydrogen-type cation resin produced by Dow Company has special adsorption capacity for copper. It is difficult for general resins to separate copper ions, and the concentration of copper ions in the final regeneration solution is only about 10g/L. However, the use of this copper-specific adsorption resin can make the concentration of metal ions in the regeneration solution higher, reaching about 40g/L, making the current The efficiency is high, and the electrolytic metal element with a purity of more than 95% can be recovered. Moreover, the ion exchange resin is not easy to be polluted, and the service life can reach 3 to 5 years, and has the characteristics of long service life.

In one embodiment, the regeneration agent is sulfuric acid solution. The choice of its concentration is a conventional choice, and it can be controlled at 5% to 10%. Sulfuric acid regeneration is used instead of hydrochloric acid regeneration to produce sulfate, and the gas generated by the anode is oxygen, which has a small corrosion effect and will not cause secondary pollution, avoiding the generation of toxic chlorine gas during electrolysis and subsequent corrosion of equipment. The tail liquid produced after electrolysis has high acidity. Moreover, when the recovered metal is copper, the copper sulfate produced after treatment with the regenerant is blue, and the regeneration end point can be judged by the color, and the regenerant can be used reasonably for regeneration to save the dosage of chemicals.

In one of the embodiments, a step of performing physical and chemical treatment on the electroplating wastewater treated with the ion exchange resin is also included. After the electroplating wastewater is treated by a combination of ion exchange resin and physical and chemical treatment, the heavy metal content in the effluent is ≤0.3mg/L, which can meet the discharge requirements and can be reused in the electroplating system, which solves the problem of electroplating wastewater, especially acid copper wastewater Difficult to meet standards and achieve emission reduction targets. The complete physical and chemical treatment process can effectively ensure that the effluent meets the influent requirements of reuse water or can meet the national discharge standards.

The present invention also provides a device for recovering heavy metals in electroplating wastewater by adopting the method for recovering heavy metals in electroplating wastewater, which includes a resin exchange treatment unit and an electrolysis recovery treatment unit connected in sequence through pipelines, and the pipeline is connected in series with a lifting device for promoting the flow of wastewater. pump; the electrolytic recovery treatment unit is a swirl electrolysis unit, which includes a swirl electrolyzer and a return device for controlling the flow rate of the liquid.

The regenerated liquid circulates through the reflux device to form a tangential force, reduce the concentration polarization, provide a good environment for electrolysis, and electrolyze the flat metal element, and it is more selective, and can electrolyze the low-concentration regenerated liquid to ensure The effect of electrolysis is improved, so that the electrolytic treatment of exchange resin regeneration solution can be applied in practical projects. The reflux device can be installed inside the swirl electrolyzer to form an internal reflux, or installed outside the swirl electrolyzer to form a reflux with the external container. The reflux device is mainly composed of a reflux pump and a flow meter, which can be controlled to generate a constant flow rate and ensure that the swirl electrolysis is carried out in a stable environment.

In one of the embodiments, the resin exchange treatment unit includes a waste water sump, a protection column, an ion exchange resin column, and a regeneration device that are connected in sequence; the regeneration device includes a regenerant dispensing box and a regeneration pump that are connected in sequence. The regeneration pump is connected with the water outlet of the ion exchange resin. The water outlet end of the ion-exchange resin column is also provided with a resin catcher, a conductivity meter and a pH meter. The resin catcher can prevent the loss of the resin and ensure that the total amount of the resin remains unchanged. The resin can also be judged according to the conductivity meter and the pH meter. Replace the situation, and use the regenerant reasonably for regeneration. The wastewater collection tank can mix the electroplating wastewater discharged in different time periods to achieve the purpose of uniform water quality. The protective column can intercept suspended matter and large particle colloids, prevent resin pores from being blocked, and ensure the resin exchange effect, thereby achieving the purpose of protecting the resin. Resin regeneration adopts countercurrent regeneration, which is beneficial to ensure the quality of effluent water. Both the guard column and the ion exchange resin column are equipped with a backwashing system to prevent suspended solids from clogging the equipment and causing an increase in pressure difference.

In one of the embodiments, there are two ion-exchange resin columns, namely ion-exchange resin column A and ion-exchange resin column B, between the water outlet end of the ion-exchange resin column A and the water inlet end of the ion-exchange resin column B, And the water outlet of ion exchange resin column B and the water inlet of ion exchange resin column A are all connected by pipelines, and switching valves are all arranged on the pipelines; the water inlets of described ion exchange resin column A and ion exchange resin column B are both Connected with the protection column, the water inlet and outlet of the ion exchange resin column A and the ion exchange resin column B are provided with valves. By adopting the above-mentioned connection method and cooperating with the opening and closing of the valve, the regenerated ion exchange resin column can be connected in series to the back of the unregenerated one to achieve a better ion exchange effect. And because the two columns are connected in series, and the resin has the same effect, when one resin column fails, the other can also operate normally, avoiding the impact of waste water on the physical and chemical treatment unit.

In one of the embodiments, the swirl electrolysis unit further includes a current stabilizer for controlling the current, a regeneration solution collection tank and an electrolyte circulation tank connected in sequence, the regeneration solution collection tank is connected to the resin exchange treatment unit, and the electrolysis The liquid circulation tank is also connected to the cyclone electrolyzer through two electrolyte circulation pipelines; the electrolyte circulation tank is also connected to the resin exchange unit through the tail liquid circulation pipe; the shell of the cyclone electrolyzer is made of insulating material , the anode is made of titanium and the cathode is made of stainless steel. After the cyclone electrolysis is completed, the electrolytic tail liquid directly enters the resin exchange unit through the tail liquid circulation pipe for resin regeneration. The shell is made of insulating material to ensure the safety of operation. The anode is made of titanium rod, which is not easy to corrode. On the one hand, it increases the service life. It is used to regenerate the resin to achieve the purpose of recycling the tail liquid. The cathode uses a stainless steel plate, which is conducive to the shedding of copper sheets and has the advantages of low price.

In one of the embodiments, the equipment further includes a physical and chemical treatment unit connected to the resin exchange treatment unit through pipelines. Putting the physical and chemical treatment process after the ion exchange, the treatment is less difficult, and it is easy to meet the standard stably. The sludge contains low heavy metals, which will not cause waste of resources, and the sludge is much less than the direct physical and chemical treatment of electroplating wastewater. The complete physical and chemical treatment process can effectively ensure that the effluent meets the influent requirements of reuse water or can meet the national discharge standards.

In one of the embodiments, the physical and chemical treatment unit includes resin effluent collection tank, pH adjustment tank, reserved oxidation tank, coagulation tank, flocculation tank, sedimentation tank and clear water tank connected in sequence; the bottom of the sedimentation tank is a slope shape, and the lowest part of the slope-shaped bottom is provided with a mud discharge pipe. Because the resin is regenerated with acid, the acidity of the effluent at the initial stage after regeneration is high, and the resin effluent in different periods is mixed and balanced here through the resin effluent collection tank, and the pH value tends to be stable, which ensures that the pH adjustment in the later stage is stable and simple; The role of water quality. When the quality of the effluent is poor and some complexes cannot be precipitated, start the reserved oxidation tank and put in the oxidant to allow the complexes to oxidize and precipitate, so that the quality of the effluent can be guaranteed.

Compared with the prior art, the present invention has the following beneficial effects:

The method for recovering heavy metals in electroplating wastewater of the present invention adopts the swirling flow electrolysis technology, which can generate tangential force under high-speed swirling flow, so that the mixed solution avoids concentration polarization, and also makes the final electrolyzed elemental metal It is smoother and more selective, and can electrolyze low-concentration regeneration solutions, that is, treat the concentration of heavy metals in the solution containing heavy metals to below 1g/L, which ensures the electrolysis effect and makes the electrolytic treatment of exchange resin regeneration solutions practical. Under construction.

In addition, because the resin regeneration agent used in this method is sulfuric acid, and the anode uses titanium rods, etc., the tail liquid after electrolysis can be directly used for regeneration, which reduces equipment investment and management. This method is a technology that turns waste into wealth, can create profits, and is applicable to actual projects, which is conducive to its implementation in electroplating wastewater treatment, creates a new situation for the treatment of electroplating wastewater, and further promotes electroplating wastewater treatment technology. development of.

The equipment for recovering heavy metals in electroplating wastewater of the present invention reduces the effect of concentration polarization through the application of the swirl electrolysis unit, provides a good environment for electrolysis, and enables the electrolytic treatment of exchange resin regeneration solution to be applied in practical projects. Moreover, the electrolytic tail liquid in the electrolytic recovery treatment unit is not polluted, and can be directly used to regenerate resin to achieve the purpose of tail liquid recycling.

At the same time, the exchange column in the resin exchange treatment unit is connected by switching, and the regenerated resin column can be connected in series to the back of the unregenerated one, so that the quality of the effluent water can be guaranteed.

Description of drawings

Fig. 1 is the connection schematic diagram of each component of the equipment of the recovery heavy metal in electroplating waste water described in embodiment 1;

Fig. 2 is a schematic diagram of connection of ion exchange resin columns A and B and the regeneration device in the equipment for recovering heavy metals in electroplating wastewater described in Example 1.

Among them: 1. Waste water collection tank; 2. Waste water lift pump; 3. Guard column; 4. Ion exchange resin column A; 5. Ion exchange resin column B; 6. Regeneration solution collection tank; 7. Regeneration solution lift pump; .Electrolyte circulation tank; 9. Electrolyte reflux pump; 10. Cyclone electrolyzer; 11. Resin outlet water collection tank; 12. Physicochemical reaction water inlet lift pump; 13. pH adjustment pool I; 15. pH adjustment tank II; 16. Coagulation tank; 17. Flocculation tank; 18. Sedimentation tank; 19. Clear water tank; 20. Sludge discharge pipeline; 21. Electrolyte circulation pipeline; Mud concentration pool; 24. Plate and frame filter press; 25. Filter cake outsourcing treatment; 26. Regeneration dispensing box; 27. Regeneration pool; 28. Tail liquid lifting pump; 29. Regeneration agent lifting pump; A. Ion exchange resin column A water inlet valve; B. Switching valve; C. Ion exchange resin column B water outlet valve; D. Ion exchange resin column B water inlet valve; E. Switching valve; F. Ion exchange resin column A water outlet G. Regenerant water inlet valve; H. Regenerant water inlet valve; I. Regenerant liquid outlet valve, J. Regenerant liquid outlet valve.

Detailed ways

The present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments.

Example 1

As shown in Figure 1, a kind of equipment that reclaims the heavy metal in the electroplating waste water, comprises the resin exchange treatment unit and the electrolytic recovery treatment unit that are connected successively by pipeline, and the physical and chemical treatment unit that is connected after the resin exchange treatment unit by pipeline, and described pipeline A lift pump to promote the flow of waste water is connected in series.

The resin exchange treatment unit includes a waste water sump 1, a waste water lift pump 2, a guard column 3, two ion exchange resin columns A4 and B5 connected in a switching manner, and a regeneration device connected in sequence. The water outlet end of the ion exchange resin column is also provided with a resin catcher, a conductivity meter and a pH meter. As shown in Figure 2, between the water outlet end of the ion exchange resin column A4 and the water inlet end of the ion exchange resin column B5, and between the water outlet end of the ion exchange resin column B5 and the water inlet end of the ion exchange resin column A4, all are connected by pipelines, Switching valves are provided on the pipelines, respectively, switching valve B and switching valve E, and the water inlet ends of ion exchange resin column A4 and ion exchange resin column B5 are connected with the guard column, and ion exchange resin column A4 and ion exchange resin column The water inlet and outlet of B5 are equipped with valves, which are water inlet valve A of ion exchange resin column A, water inlet valve D of ion exchange resin column B, water outlet valve F of ion exchange resin column A, water outlet valve of ion exchange resin column B c. In practical application, water can be taken in by water inlet valve A, water out by switch valve B, then water in by water inlet valve D, enters ion exchange column B, and water out by water outlet valve C; water can also be taken in by water inlet valve D, Switch valve E to discharge water, then enter ion exchange column A, and discharge valve F to discharge water; through the above switching method, the regenerated ion exchange resin column can be connected in series to the unregenerated back to achieve better ion exchange effect. The regeneration device includes a regenerant dispensing box 26 , a regenerant agent lift pump 29 connected in sequence, and a regenerated water pool 27 connected to the water outlet of the ion exchange resin column through a regenerated water pump 30 . The regenerated water pump 30 is connected to the water outlets of the ion exchange resin column A4 and the ion exchange resin column B5 respectively through pipelines, the pipelines are respectively provided with a regenerant water inlet valve G and a regenerant water inlet valve H, and the ion exchange The water inlet ends of the resin column A4 and the ion-exchange resin column B5 are also provided with a regeneration liquid outlet valve I and a regeneration liquid outlet valve J respectively, and the regeneration liquid outlet valve I and the regeneration liquid outlet valve J are connected to the regeneration liquid in the swirling flow electrolysis unit. The collection tank 6 is connected. When the ion-exchange resin column B5 is regenerated, water can be fed into the water inlet valve A and water out from the water outlet valve F; when the ion-exchange column resin A4 is regenerated, water can be fed into the water inlet valve D and water out from the water outlet valve C to realize switching and ensure continuous operation. Regenerated agent can enter ion exchange column resin A4 or ion exchange resin column B5 from water inlet valve G or water inlet valve H, and regeneration liquid comes out from outlet valve I or outlet valve J.

The electrolytic recovery treatment unit is a swirl electrolysis unit, which includes a swirl electrolyzer 10, a return device for controlling the flow rate of the liquid, and a current stabilizer for controlling the current. The return device is mainly composed of a return pump (in this example, the electrolyte return pump 9 ) and a flow meter. The swirling flow electrolysis unit also includes a regeneration solution collection tank 6, a regeneration solution lifting pump 7 and an electrolyte circulation tank 8 connected in sequence, the regeneration solution collection tank 6 is connected to an ion exchange resin column, and the electrolyte circulation tank 8 is also It is connected with the cyclone electrolyzer through two electrolyte circulation pipelines 21, and the return pump and flow meter are arranged on the circulation pipeline; the electrolyte circulation tank 8 is also connected with the regeneration agent dispensing box 26 in the resin exchange unit It is connected through a tail liquid circulation pipe, on which a tail liquid lifting pump 28 is arranged; the shell of the cyclone electrolyzer 10 is made of insulating material, the anode is made of titanium, and the cathode is made of stainless steel.

The physical and chemical treatment unit includes sequentially connected resin outlet water collection tank 11, physical and chemical reaction water inlet lift pump 12, pH adjustment tank I13, reserved oxidation tank 14, pH adjustment tank II15, coagulation tank 16, flocculation tank 17, sedimentation tank 18 and a clear water tank 19; the bottom of the sedimentation tank 18 is slope-shaped, and the lowest point of the slope-shaped bottom is provided with a mud discharge pipe 20.

Example 2

The method of reclaiming the heavy metals in the electroplating wastewater by the equipment of the recovery electroplating wastewater of embodiment 1 is as follows:

First, the electroplating industrial acid copper wastewater with a copper ion concentration of 200-300 mg/L enters the wastewater collection tank 1 and stays there for 6 hours, which can stabilize the water quality. The protective column 3 is equipped with an inert resin (plastic floating ball), which is used to intercept suspended matter and part of the colloidal matter in the waste water. The purpose is to reduce the suspended matter from entering the ion exchange resin column and improve the operation stability of the ion exchange resin column. Then enter the series ion exchange resin column A4 and ion exchange resin column B5. The ion exchange resin column adopts the Ambersep M64 resin developed by Dow that has special adsorption for copper. The exchange column tank is 3000mm in diameter and 4000mm in height. Cylindrical, filled with 10 cubic resin, the processing flow rate is maintained at 90m ³ /h. The two ion-exchange resin columns are operated in a switching mode, and the waste water passes through the unregenerated ion-exchange resin column first, and then through the regenerated ion-exchange resin column to ensure the quality of the effluent.

The electroplating wastewater passing through the ion exchange resin column enters the resin outlet water collection tank 11 for mixing, stays for 1 hour to make the water quality more stable, and then enters the water through the physical and chemical reaction into the lifting pump 12 with an effective volume of 40m ³ , and a large-hole aeration head is installed at the bottom In the pH adjustment pool I13, adjust the pH with sodium hydroxide and stay for 27 minutes. The reason for choosing to use sodium hydroxide to adjust pH is that it has good water solubility and is not easy to precipitate in the solution. If calcium hydroxide is used to adjust pH, its solubility is low, which may cause problems of blocking other equipment during reuse. Then enter the reserved oxidation tank 14 with an effective volume of 135m ^{3 and} a large-pore aeration head at the bottom to stay for 1.5h, and then enter the pH adjustment tank II15 with an effective volume of 40m ³ and a large-pore aeration head at the bottom. Adjust the pH with sodium hydroxide and stay for 27min. Then enter the coagulation tank 16 with an effective volume of 40m ³ and a large-hole aeration head at the bottom, and add PAC (polyaluminum chloride) as a coagulant. At this time, the aeration mainly plays the role of mixing wastewater and stays for 27 minutes. . Then enter the flocculation tank 17 with an effective volume of 40m ³ , a large-hole aeration head at the bottom, and a mixer for 27 minutes. At this time, the aeration volume is small, and the mixer is mainly used to stir the flocs so that the flocs are not broken up. Then enter the sedimentation tank 18 with an effective volume of 180m ³ , which is divided into a gravity sedimentation area (effective volume: 90m ³ ) and an inclined tube sedimentation area (effective volume: 90m ³ ) and stay in the sedimentation tank 18 for 2 hours. The clear water after sedimentation enters the clear water tank 19 with an effective volume of 135m ³ and a large-hole aeration head installed at the bottom, adjusts the pH value as required, and stays there for 1.5 hours. The final treated clean water meets the requirements and is discharged up to the standard 22 or can be reused in the reclaimed water reuse system, with a reuse rate higher than 60%. The sludge obtained through sedimentation is discharged from the sludge discharge pipe 20 and enters the sludge thickening tank 23 . After being filtered by the plate and frame filter press 24 , the filter cake is formed, and the filter cake is outsourced 25 .

When the ion exchange resin column needs to be regenerated according to the conductivity meter, pH meter or color, use 5% sulfuric acid to regenerate in the middle row, and use an electronic flowmeter or rotameter to control the regeneration flow rate to 2BV/h, and the regeneration consumes 5% sulfuric acid. 1.5-2BV of the resin, the low-concentration regeneration solution produced is used for regeneration.

The eluted regeneration solution enters the regeneration solution collection tank 6, which has a volume of 20m ³ to ensure that it can hold the twice-regenerated electrolyte. According to needs, another regeneration solution collection tank can also be provided. It mainly collects low-concentration regeneration solution for mechanical regeneration. The regenerated liquid with a suitable concentration is lifted by the regenerated liquid lift pump 7 into the electrolyte circulation tank 8, and due to the action of the electrolyte return pump 9, the regenerated liquid passes through the electrolyte circulation pipeline 21 in the swirl electrolyzer 10 and the electrolyte circulation tank A closed reflux system is formed in 8 to ensure that the liquid in the swirl electrolyzer 10 circulates at a high speed all the time, forming a tangential force and electrolyzing flat copper sheets. During swirl electrolysis, the flow rate is controlled to be 0.4m/s, the voltage is 2.4V, the current density is 100A/M ² , and electrolysis is performed at 15°C. The purity of copper obtained by electrolysis is above 99%. The tail liquid generated after electrolysis is used again to regenerate the resin to achieve the purpose of recycling the tail liquid.

Example 3

Adopt the method that the heavy metal in the recovery electroplating waste water of embodiment 1 carries out the method for reclaiming heavy metal in the electroplating waste water, differs from embodiment 2 in that:

(1) When the ion exchange resin column is regenerated, 10% sulfuric acid is used to regenerate in the countercurrent middle row.

(2) During swirl electrolysis, control the flow rate to 0.6m/s, voltage 4V, current density 200A/M ² , and electrolyze at 25°C.

Embodiment 4 electroplating wastewater treatment result

The water samples at various stages in the treatment process of the above-mentioned Examples 2 and 3 were taken, and the copper ion content, conductivity and pH value were detected. The results are shown in Table 1 below.

Table 1. Table of water samples at each stage of electroplating wastewater treatment.

It can be seen from the results in Table 1 above that after treatment, the copper ion content in the electroplating wastewater was significantly reduced, meeting the requirements of the "Electroplating Industry Water Pollutant Discharge Standard".

Example 5 Ion-exchange resin adsorption copper ion effect test

According to the method in Example 2, the electroplating wastewater was treated with different resins, the resin was regenerated by the method in Example 2, and the concentration of copper ions in the regeneration solution was detected. The results are shown in Table 2 below.

Table 2. The concentration of copper ions in the regeneration solution after ion exchange with different resins.

It can be seen from the results in Table 2 above that after the electroplating wastewater is treated with the copper-specific adsorption resin in Example 2, the concentration of copper ions in the regeneration solution is much higher than that of other resins, which provides a guarantee for the effect of the subsequent swirl electrolysis.

The above-mentioned embodiments only express several implementation modes of the present invention, and the description thereof is relatively specific and detailed, but should not be construed as limiting the patent scope of the present invention. It should be pointed out that those skilled in the art can make several modifications and improvements without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent for the present invention should be based on the appended claims.

Claims (3)

1. reclaim a method for heavy metal out of electroplating wastewater, it is characterized in that comprising the following steps:

(1) electroplating wastewater is carried out to ion exchange resin treatment, make heavy metal ion adsorbed on ion exchange resin in electroplating wastewater;

(2) be adsorbed in the heavy metal ion on ion exchange resin with regenerator wash-out, obtain regenerated liquid;

(3) adopt cyclone electrolytic cell technology, control, controls flow is 0.4m/s, voltage 2.4V, and current density 100A/M2, electrolysis at 15 DEG C, makes to belong on negative potential and separate out with much money; Described ion exchange resin is the special polymeric adsorbent of copper; Described regenerator is sulphuric acid soln, and concentration is 5%～10%;

Also comprise the step of the electroplating wastewater through ion exchange resin treatment being carried out to materialization processing;

Wherein, the method that reclaims heavy metal out of electroplating wastewater adopts the equipment that reclaims heavy metal in electroplating wastewater, described equipment comprises the resins exchange processing unit and the electrolytic recovery processing unit that connect successively by pipeline, is in series with and promotes the mobile lift pump of waste water on described pipeline; Described electrolytic recovery processing unit is cyclone electrolytic cell unit, and this cyclone electrolytic cell unit comprises cyclone electrolytic cell device and controls the reflux of flow rate of liquid;

Described resins exchange processing unit comprises the wastewater collecting basin, guard column, ion exchange resin column, the regenerating unit that connect successively; Described regenerating unit comprises the regenerator Scatula, the regenerative pump that connect successively, and described regenerative pump is connected with ion exchange resin water side;

Described ion exchange resin column is two, be respectively ion exchange resin column A and ion exchange resin column B, between this ion exchange resin column A water side and ion exchange resin column B water intake end, and be all connected by pipeline between ion exchange resin column B water side and ion exchange resin column A water intake end, on this pipeline, be equipped with switching valve; The water intake end of described ion exchange resin column A and ion exchange resin column B is all connected with guard column, and water intake end and the water side of ion exchange resin column A and ion exchange resin column B are equipped with valve.

2. the method for recovery heavy metal out of electroplating wastewater according to claim 1, it is characterized in that: described cyclone electrolytic cell unit also comprises regenerated liquid receiving tank and the circulation of elecrolyte groove of controlling the current stabilizer of electric current, connection successively, described regenerated liquid receiving tank connects resin switch processing unit, and described circulation of elecrolyte groove is also interconnection by two circulation of elecrolyte pipelines with cyclone electrolytic cell device; Described circulation of elecrolyte groove is also connected by tail washings circulation tube with resins exchange unit; Described cyclone electrolytic cell device shell is made up of insulating material, and anode is made of titanium, and negative electrode is made up of stainless steel.

3. the method for recovery heavy metal out of electroplating wastewater according to claim 1, is characterized in that: described equipment also comprises by pipeline and is connected in the physicochemical treatment unit after resins exchange processing unit.