Electroplating nickel-containing wastewater treatment method

Abstract

The invention discloses an electroplating nickel-containing wastewater treatment method which comprises a wastewater collection system, a pretreatment system, a separation system, a concentration system, a hyperconcentration system and a sludge treatment system. The wastewater collection system comprises a wastewater collection pool and a collection pool lifting pump; the pretreatment system comprises a microfiltration concentrated water tank, a microfiltration circulating pump, a microfiltration membrane device, a microfiltration water producing tank, a microfiltration water producing tank booster pump and a carbon filter; the separation system comprises a security filter, a separation high-pressure pump, a separation device, a fresh water tank and a fresh water recycling pump; the concentration system comprises a concentration water tank, a concentration high-pressure pump and a concentration device; the hyper-concentration system comprises a hyper-concentration water tank, a hyper-concentration high-pressure pump, a hyper-concentration device, a hyper-concentration water tank booster pump, a concentrated solution collecting tank and a concentrated solution recycling pump; the sludge treatment system comprises a sludge tank, a sludge pump and a sludge dewatering machine. The system is high in automation degree, the conductivity of fresh water generated by the system reaches 200 us / cm or below, and the fresh water can be reused in a rinsing bath of an electroplating production line; the concentration of nickel contained in the concentrated solution is not lower than 40g / L, and the concentrated solution can be reused in a production line electroplating mother bath.

Description

Technical Field

[0001] The present invention belongs to the technical field of wastewater treatment, and particularly relates to a method for treating nickel-containing electroplating wastewater. Background Art

[0002] Nickel-containing wastewater mainly comes from the rinsing water in the nickel plating section of the electroplating production line. If it is discharged into the water body without effective treatment, it will cause serious impacts on the environment and human health. In addition, due to the high price of nickel and the continuous reduction of nickel resources, nickel-containing wastewater has high recycling value. If the nickel-containing electroplating wastewater can be recycled, it can not only reduce environmental pollution, but also reduce the production cost of enterprises, save water resources and promote the clean production level of the industry.

[0003] Membrane concentration separation technology has been widely used in the treatment of heavy metal wastewater. Generally, when only using a reverse osmosis membrane to concentrate heavy metal wastewater, the concentration limit is relatively large, and it is difficult for the concentration of the concentrated liquid after concentration to reach the concentration of the electroplating solution in the electroplating mother tank. Summary of the Invention

[0004] The purpose of the present invention is to provide a method for treating nickel-containing electroplating wastewater to separate and concentrate the nickel-containing electroplating wastewater, so as to achieve the purpose that the concentrated liquid can be reused in the electroplating mother tank of the production line, and the fresh water can be reused in the water washing tank of the electroplating production line.

[0005] To achieve the above purpose, the technical solution adopted by the present invention is: A method for treating nickel-containing electroplating wastewater, which includes a wastewater collection system, a pretreatment system, a separation system, a concentration system, an ultra-concentration system, and a sludge treatment system; the wastewater collection system includes a wastewater collection tank and a collection tank lift pump; the pretreatment system includes a microfiltration concentration water tank, a microfiltration circulation pump, a microfiltration membrane device, a microfiltration product water tank, a microfiltration product water tank booster pump, and a carbon filter; the separation system includes a security filter, a separation high-pressure pump, a separation device, a fresh water tank, and a fresh water reuse pump; the concentration system includes a concentration water tank, a concentration high-pressure pump, and a concentration device; the ultra-concentration system includes an ultra-concentration water tank, an ultra-concentration high-pressure pump, an ultra-concentration device, an ultra-concentration water tank booster pump, a concentrated liquid collection tank, and a concentrated liquid reuse pump; the sludge treatment system includes a sludge tank, a sludge pump, and a sludge dehydrator.

[0006] The water outlet of the wastewater collection tank is connected to the water inlet of the collection tank lift pump; the water outlet of the collection tank lift pump is connected to the water inlet of the microfiltration and concentration water tank; the water outlet of the microfiltration and concentration water tank is connected to the water inlet of the microfiltration circulation pump; the water outlet of the microfiltration circulation pump is respectively connected to the water inlets of the microfiltration membrane device and the sludge tank; the fresh water outlet of the microfiltration membrane device is connected to the water inlet of the microfiltration product water tank, and the concentrated water outlet of the microfiltration membrane device is connected to the water inlet of the microfiltration and concentration water tank; the water outlet of the microfiltration product water tank is connected to the water inlet of the microfiltration product water tank lift pump; the water outlet of the microfiltration product water tank booster pump is connected to the water inlet of the carbon filter; the water outlet of the carbon filter is connected to the water inlet of the security filter; the water outlet of the security filter is connected to the water inlet of the separation high-pressure pump; the fresh water outlet of the separation device is connected to the water inlet of the fresh water tank, and the concentrated water outlet of the separation device is connected to the water inlet of the concentration water tank; the water outlet of the concentration water tank is connected to the water inlet of the concentration high-pressure pump; the water outlet of the concentration high-pressure pump is connected to the water inlet of the concentration device; the fresh water outlet of the concentration device is connected to the water inlet of the microfiltration product water tank, and the concentrated water outlet of the concentration device is connected to the water inlet of the ultra-concentration water tank; the water outlet of the ultra-concentration water tank is respectively connected to the water inlets of the ultra-concentration high-pressure pump and the ultra-concentration water tank booster pump; the water outlet of the ultra-concentration high-pressure pump is connected to the water inlet of the ultra-concentration device; the fresh water outlet of the ultra-concentration device is connected to the water inlet of the concentration water tank, and the concentrated water outlet of the ultra-concentration device is connected to the water inlet of the ultra-concentration water tank; the water outlet of the fresh water tank is connected to the water inlet of the fresh water reuse pump; the water outlet of the fresh water reuse pump is connected to the water washing tank of the production line; the water outlet of the ultra-concentration water tank booster pump is connected to the water inlet of the concentrated liquid collection tank; the water outlet of the concentrated liquid collection tank is connected to the water inlet of the concentrated liquid reuse pump; the water outlet of the concentrated liquid reuse pump is connected to the electroplating mother tank of the production line; the water outlet of the sludge tank is connected to the water inlet of the sludge pump; the water outlet of the sludge pump is connected to the water inlet of the sludge dehydrator.

[0007] As a further preference of this solution, a foot valve is provided at the bottom of the water inlet pipeline of the collection tank lift pump.

[0008] As a further preference of this solution, the pretreatment system uses a microfiltration membrane device and a carbon filter to filter the wastewater.

[0009] As a further preference of this solution, the wastewater in the microfiltration and concentration water tank is sent into the microfiltration membrane device through the microfiltration circulation pump for circulating filtration, and the final waste liquid in the microfiltration and concentration water tank is regularly discharged into the sludge treatment system through the microfiltration circulation pump for treatment.

[0010] As a further preference of this solution, the separation device uses a reverse osmosis membrane for brackish water desalination to separate the wastewater; both the concentration device and the ultra-concentration device use D-series nanofiltration membranes to concentrate the wastewater.

[0011] As a further preference of this solution, the fresh water tank is used to collect the fresh water from the separation device. With a conductivity of less than 200 us / cm, it can be reused in the water washing tank of the electroplating production line.

[0012] As a further preference of this solution, the wastewater in the ultra-concentrated water tank is sent into the ultra-concentration device through the ultra-concentrated high-pressure pump for circulating concentration treatment. The concentration of nickel in the concentrated liquid is not less than 40 g / L, and finally it is sent into the concentrated liquid collection tank through the ultra-concentrated water tank booster pump for collection and reused in the electroplating mother tank of the production line.

[0013] As a further preference of this solution, both the fresh water reuse pump and the concentrated liquid reuse pump are variable-frequency constant-pressure pumps. The fresh water reuse pump is provided with a ball valve on its outlet pipeline and near the water washing tank of the production line to control the reuse water from entering the water washing tank. When the ball valve is opened, the internal pressure of the pipeline decreases, and the fresh water reuse pump is turned on, and the fresh water is sent into the water washing tank. When the ball valve is closed, the internal pressure of the pipeline rises, and the fresh water reuse pump is turned off, and the fresh water stops being sent into the water washing tank. The concentrated liquid reuse pump is provided with a ball valve on its outlet pipeline and near the electroplating mother tank of the production line to control the tank liquid from entering the electroplating mother tank. When the ball valve is opened, the internal pressure of the pipeline decreases, and the concentrated liquid reuse pump is turned on, and the concentrated liquid is sent into the electroplating mother tank. When the ball valve is closed, the internal pressure of the pipeline rises, and the concentrated liquid reuse pump is turned off, and the concentrated liquid stops being sent into the electroplating mother tank.

[0014] As a further preference of this solution, the sewage generated by the sludge dewatering machine flows back to the wastewater collection pool, and the generated sludge is entrusted to a professional agency for disposal as hazardous waste.

[0015] As a further preference of this solution, a liquid level control system is provided in the wastewater collection tank to control the start and stop of the collection tank lift pump. When the liquid level is high, the collection tank lift pump starts; when the liquid level is low, the collection tank lift pump stops. A liquid level control system is provided in the microfiltration and concentration water tank to control the start and stop of the microfiltration circulation pump. When the liquid level is high, the microfiltration circulation pump starts; when the liquid level is low, the microfiltration circulation pump stops. A liquid level control system is provided in the microfiltration product water tank to control the start and stop of the microfiltration product water tank booster pump and the separation high-pressure pump. When the liquid level is high, the microfiltration product water tank booster pump and the separation high-pressure pump start in sequence; when the liquid level is low, the separation high-pressure pump and the microfiltration product water tank booster pump stop in sequence. A liquid level control system is provided in the fresh water tank to control the start and stop of the separation high-pressure pump and the fresh water reuse pump. When the liquid level is high, the separation high-pressure pump stops; when the liquid level is low, the fresh water reuse pump stops. A liquid level control system is provided in the concentrated water tank to control the start and stop of the concentrated high-pressure pump. When the liquid level is high, the concentrated high-pressure pump starts; when the liquid level is low, the concentrated high-pressure pump stops. A liquid level gauge is provided in the ultra-concentrated water tank to control the start and stop of the ultra-concentrated high-pressure pump and the ultra-concentrated water tank booster pump. When the liquid level is high, the ultra-concentrated high-pressure pump starts; when the liquid level is low, the ultra-concentrated high-pressure pump and the ultra-concentrated water tank booster pump stop. A liquid level control system is provided in the concentrated liquid collection tank to control the start and stop of the ultra-concentrated water tank booster pump and the concentrated liquid reuse pump. When the liquid level is high, the ultra-concentrated water tank booster pump stops; when the liquid level is low, the concentrated liquid reuse pump stops. A liquid level control system is provided in the sludge tank to control the start and stop of the sludge pump. When the liquid level is high, the sludge pump starts; when the liquid level is low, the sludge pump stops.

[0016] The beneficial effects of the present invention are as follows: (1) A bottom valve is provided at the bottom of the inlet pipe of the collection tank lift pump, which can prevent the backflow of water in the water pump and reduce the inflow of sundries, reducing the risk of system blockage.

[0017] (2) The pretreatment system adopts a microfiltration membrane device and a carbon filter. The microfiltration membrane device mainly uses a microporous membrane to intercept and separate suspended solids with a particle size greater than or equal to its pore size (50 - 1000 nm). The diameter of nickel ions is 0.110 - 0.138 nm, which can pass through the microfiltration membrane device and enter the microfiltration product water tank; and the microfiltration membrane device can eliminate the sedimentation tank and multi-media filtration, without the need to add flocculants. Through the concentration effect of the tubular membrane, there are enough suspended solids in the concentration tank to promote coprecipitation. Generally, the overall sludge volume is less than that of the traditional process, with a higher concentration, and it can be directly sent to the sludge dewatering machine without further concentration. The carbon filter is mainly used to remove organic matter to avoid the fouling of the membrane by organic matter.

[0018] (3) The separation device adopts a reverse osmosis membrane for brackish water desalination, and the conductivity of the produced fresh water reaches below 200 us / cm, which can be reused in the water washing tank of the electroplating production line.

[0019] (4) The concentration device and the ultra-concentration device both use the nanofiltration membrane of the D series to concentrate the wastewater. It can not only intercept divalent nickel ions, but also reduce the pressure requirements for the high-pressure pump and pipeline compared with the seawater desalination membrane. The nickel concentration in the concentrated liquid is not less than 40 g / L and can be recycled to the electroplating mother tank of the production line.

[0020] (5) The fresh water reuse pump and the concentrated liquid reuse pump both use variable frequency constant pressure pumps. The reuse of fresh water and concentrated liquid only needs to open the corresponding ball valves for control, which can not only protect the reuse pump, but also has a high degree of automation of the system.

[0021] (6) In the wastewater collection tank, microfiltration concentration water tank, microfiltration product water tank, concentration water tank, ultra-concentration water tank, fresh water tank and concentrated liquid collection tank, the start and stop of the pump are controlled by setting a liquid level control system, which can realize the automatic operation of the wastewater treatment system. Description of the Drawings

[0022] Figure 1 It is the process flow chart of a method for treating electroplating nickel-containing wastewater of the present invention.

[0023] Reference numerals in the figure: 1 is the wastewater collection tank, 2 is the collection tank lift pump, 3 is the microfiltration concentration water tank, 4 is the microfiltration circulation pump, 5 is the microfiltration membrane device, 6 is the microfiltration product water tank, 7 is the microfiltration product water tank booster pump, 8 is the carbon filter; 9 is the security filter, 10 is the separation high-pressure pump, 11 is the separation device, 12 is the fresh water tank, 13 is the fresh water reuse pump, 14 is the concentration water tank, 15 is the concentration high-pressure pump, 16 is the concentration device, 17 is the ultra-concentration water tank, 18 is the ultra-concentration high-pressure pump, 19 is the ultra-concentration device, 20 is the ultra-concentration booster pump, 21 is the concentrated liquid collection tank, 22 is the concentrated liquid reuse pump, 23 is the sludge tank, 24 is the sludge pump, 25 is the sludge dehydrator. Embodiments

[0024] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0025] Such as Figure 1As shown in the figure, a method for treating nickel-containing electroplating wastewater includes a wastewater collection system, a pretreatment system, a separation system, a concentration system, an ultra-concentration system, and a sludge treatment system; the wastewater collection system includes a wastewater collection tank 1 and a collection tank lift pump 2; the pretreatment system includes a microfiltration concentrated water tank 3, a microfiltration circulation pump 4, a microfiltration membrane device 5, a microfiltration product water tank 6, a microfiltration product water tank booster pump 7, and a carbon filter 8; the separation system includes a security filter 9, a separation high-pressure pump 10, a separation device 11, a fresh water tank 12, and a fresh water reuse pump 13; the concentration system includes a concentration water tank 14, a concentration high-pressure pump 15, and a concentration device 16; the ultra-concentration system includes an ultra-concentration water tank 17, an ultra-concentration high-pressure pump 18, an ultra-concentration device 19, an ultra-concentration booster pump 20, a concentrated liquid collection tank 21, and a concentrated liquid reuse pump 22; the sludge treatment system includes a sludge tank 23, a sludge pump 24, and a sludge dehydrator 25.

[0026] The water outlet of the wastewater collection tank 1 is connected to the water inlet of the collection tank lift pump 2; the water outlet of the collection tank lift pump 2 is connected to the water inlet of the microfiltration and concentration water tank 3; the water outlet of the microfiltration and concentration water tank 3 is connected to the water inlet of the microfiltration circulation pump 4; the water outlet of the microfiltration circulation pump 4 is respectively connected to the water inlets of the microfiltration membrane device 5 and the sludge tank 23; the fresh water outlet of the microfiltration membrane device 5 is connected to the water inlet of the microfiltration product water tank 6, and the concentrated water outlet of the microfiltration membrane device 5 is connected to the water inlet of the microfiltration and concentration water tank 3; the water outlet of the microfiltration product water tank 6 is connected to the water inlet of the microfiltration product water tank lift pump 7; the water outlet of the microfiltration product water tank booster pump 7 is connected to the water inlet of the carbon filter 8; the water outlet of the carbon filter 8 is connected to the water inlet of the security filter 9; the water outlet of the security filter 9 is connected to the water inlet of the separation high-pressure pump 10; the fresh water outlet of the separation device 11 is connected to the water inlet of the fresh water tank 12, and the concentrated water outlet of the separation device 11 is connected to the water inlet of the concentration water tank 14; the water outlet of the concentration water tank 14 is connected to the water inlet of the concentration high-pressure pump 15; the water outlet of the concentration high-pressure pump 15 is connected to the water inlet of the concentration device 16; the fresh water outlet of the concentration device 16 is connected to the water inlet of the microfiltration product water tank 6, and the concentrated water outlet of the concentration device 16 is connected to the water inlet of the ultra-concentration water tank 17; the water outlet of the ultra-concentration water tank 17 is respectively connected to the water inlets of the ultra-concentration high-pressure pump 18 and the ultra-concentration water tank booster pump 20; the water outlet of the ultra-concentration high-pressure pump 18 is connected to the water inlet of the ultra-concentration device 19; the fresh water outlet of the ultra-concentration device 19 is connected to the water inlet of the concentration water tank 14, and the concentrated water outlet of the ultra-concentration device 19 is connected to the water inlet of the ultra-concentration water tank 17; the water outlet of the fresh water tank 12 is connected to the water inlet of the fresh water reuse pump 13; the water outlet of the fresh water reuse pump 13 is connected to the production line washing tank; the water outlet of the ultra-concentration water tank booster pump 20 is connected to the water inlet of the concentrated liquid collection tank 21; the water outlet of the concentrated liquid collection tank 21 is connected to the water inlet of the concentrated liquid reuse pump 22; the water outlet of the concentrated liquid reuse pump 22 is connected to the production line electroplating mother tank; the water outlet of the sludge tank 23 is connected to the water inlet of the sludge pump 24; the water outlet of the sludge pump 24 is connected to the water inlet of the sludge dehydrator 25.

[0027] A foot valve is provided at the bottom of the water inlet pipeline of the collection tank lift pump 2 to prevent the backflow of water in the water pump and reduce the inflow of sundries, thereby reducing the risk of system blockage.

[0028] The pretreatment system uses the microfiltration membrane device 5 and the carbon filter 8 to filter the wastewater.

[0029] The wastewater in the microfiltration and concentration water tank 3 is sent into the microfiltration membrane device 5 through the microfiltration circulation pump 4 for circulating filtration, and the final waste liquid in the microfiltration and concentration water tank 3 is regularly discharged into the sludge treatment system through the microfiltration circulation pump 4 for treatment.

[0030] The separation device 11 uses a reverse osmosis membrane for brackish water desalination to separate the wastewater; both the concentration device 16 and the ultra-concentration device 19 use a nanofiltration membrane of the D series to concentrate the wastewater.

[0031] The fresh water tank 12 is used to collect the fresh water from the separation device 11. The conductivity reaches below 200 us / cm and can be reused in the water washing tank of the electroplating production line.

[0032] The wastewater in the ultra-concentration water tank 17 is sent into the ultra-concentration device 19 by the ultra-concentration high-pressure pump 18 for circulating concentration treatment. The concentration of nickel in the concentrated liquid is not less than 40 g / L, and finally it is sent into the concentrated liquid collection tank 21 by the ultra-concentration water tank booster pump 20 for collection and reused in the electroplating master tank of the production line.

[0033] Both the fresh water reuse pump 13 and the concentrated liquid reuse pump 22 use variable frequency constant pressure pumps. The fresh water reuse pump 13 is provided with a ball valve on its outlet pipeline and near the water washing tank of the production line to control the recycled water from entering the water washing tank. When the ball valve is opened, the internal pressure of the pipeline decreases, and the fresh water reuse pump 13 is turned on, and the fresh water is sent into the water washing tank. When the ball valve is closed, the internal pressure of the pipeline rises, and the fresh water reuse pump 13 is turned off, and the fresh water stops being sent into the water washing tank. The concentrated liquid reuse pump 22 is provided with a ball valve on its outlet pipeline and near the electroplating master tank of the production line to control the bath solution from entering the electroplating master tank. When the ball valve is opened, the internal pressure of the pipeline decreases, and the concentrated liquid reuse pump 22 is turned on, and the concentrated liquid is sent into the electroplating master tank. When the ball valve is closed, the internal pressure of the pipeline rises, and the concentrated liquid reuse pump 22 is turned off, and the concentrated liquid stops being sent into the electroplating master tank.

[0034] The sewage generated by the sludge dewatering machine 25 flows back to the wastewater collection tank 1, and the generated sludge is entrusted to a professional agency for disposal as hazardous waste.

[0035] A liquid level control system is provided in the wastewater collection tank 1 to control the start and stop of the collection tank lift pump 2. When the liquid level is high, the collection tank lift pump 2 starts; when the liquid level is low, the collection tank lift pump 2 stops. A liquid level control system is provided in the microfiltration and concentration water tank 3 to control the start and stop of the microfiltration circulation pump 4. When the liquid level is high, the microfiltration circulation pump 4 turns on; when the liquid level is low, the microfiltration circulation pump 4 stops. A liquid level control system is provided in the microfiltration product water tank 6 to control the start and stop of the microfiltration product water tank booster pump 7 and the separation high-pressure pump 10. When the liquid level is high, the microfiltration product water tank booster pump 7 and the separation high-pressure pump 10 are turned on in sequence; when the liquid level is low, the separation high-pressure pump 10 and the microfiltration product water tank booster pump 7 stop in sequence. A liquid level control system is provided in the fresh water tank 12 to control the start and stop of the separation high-pressure pump 11 and the fresh water reuse pump 13. When the liquid level is high, the separation high-pressure pump 11 stops; when the liquid level is low, the fresh water reuse pump 13 stops. A liquid level control system is provided in the concentrated water tank 14 to control the start and stop of the concentrated high-pressure pump 15. When the liquid level is high, the concentrated high-pressure pump 15 turns on; when the liquid level is low, the concentrated high-pressure pump 15 stops. A liquid level gauge is provided in the ultra-concentrated water tank 17 to control the start and stop of the ultra-concentrated high-pressure pump 18 and the ultra-concentrated water tank booster pump 20. When the liquid level is high, the ultra-concentrated high-pressure pump 18 turns on; when the liquid level is low, the ultra-concentrated high-pressure pump 18 and the ultra-concentrated water tank booster pump 20 stop. A liquid level control system is provided in the concentrated liquid collection tank 21 to control the start and stop of the ultra-concentrated water tank booster pump 20 and the concentrated liquid reuse pump 22. When the liquid level is high, the ultra-concentrated water tank booster pump 20 stops; when the liquid level is low, the concentrated liquid reuse pump 22 stops. A liquid level control system is provided in the sludge tank 23 to control the start and stop of the sludge pump 24. When the liquid level is high, the sludge pump 24 turns on; when the liquid level is low, the sludge pump 24 stops.

[0036] During use: The nickel-containing electroplating wastewater enters the wastewater collection tank 1 by overflow, and then is sent into the microfiltration and concentration water tank 3 by the collection tank lift pump 2, and is sent into the microfiltration membrane device 5 by the microfiltration circulation pump 4 for circulating filtration to remove suspended solids. The waste liquid in the microfiltration and concentration water tank 3 is regularly discharged into the sludge treatment system by the microfiltration circulation pump 4 for treatment. The water filtered by the microfiltration membrane device 5 enters the microfiltration product water tank 6, and then is sent into the carbon filter 8 by the microfiltration product water tank booster pump 7 to remove organic matters, and after removing fine particles through the security filter 9, it is then sent into the separation device 11 by the high-pressure pump 10 for separation; the fresh water from the separation device 11 enters the fresh water tank 12 for storage and can be reused in the electroplating production line washing tank. The concentrated water generated by the separation device 11 enters the concentrated water tank 14, and then is sent into the concentration device 16 by the concentrated high-pressure pump 15 for primary concentration. The fresh water from the concentration device 16 returns to the front-end microfiltration product water tank 6, and the concentrated water enters the ultra-concentrated water tank 17; then it is sent into the ultra-concentration device 19 by the ultra-concentrated high-pressure pump 18 for secondary circulating concentration. The fresh water returns to the front-end concentrated water tank 14, and the concentrated water is concentrated into a concentrated liquid with a nickel content of not less than 40 g / L, and is sent into the concentrated liquid collection tank 21 by the ultra-concentrated water tank booster pump 20. The concentrated liquid can be reused in the electroplating mother tank of the production line.

[0037] In summary, for the nickel-containing electroplating wastewater treatment method of the present invention, the pretreatment system uses a microfiltration membrane device and a carbon filter to filter the wastewater, which can not only intercept and separate suspended solids but also retain nickel ions that need to be recovered. Moreover, sedimentation tanks and multimedia filtration can be omitted, and flocculants do not need to be added. Generally, the overall sludge volume is less than that of traditional processes, and the concentration is relatively high, so it can be directly sent to the sludge dewatering machine without further concentration. The carbon filter can effectively prevent the fouling of the membrane by organic matter. The separation device uses a reverse osmosis membrane for brackish water desalination, and the conductivity of the produced fresh water reaches below 200 us / cm, which can be reused in the water washing tank of the electroplating production line. Both the concentration device and the ultra-concentration device use D-series nanofiltration membranes to concentrate the wastewater, which can not only intercept divalent nickel ions but also reduce the pressure requirements for high-pressure pumps and pipelines compared with seawater desalination membranes. The nickel concentration in the concentrated liquid is not less than 40 g / L and can be reused in the electroplating mother tank of the production line. Both the fresh water reuse pump and the concentrated liquid reuse pump use variable frequency constant pressure pumps. When reusing, only the corresponding ball valves need to be opened for control, which not only protects the reuse pumps but also improves the automation level of the system. In the wastewater collection tank, microfiltration concentration water tank, microfiltration product water tank, concentration water tank, ultra-concentration water tank, fresh water tank, and concentrated liquid collection tank, the start and stop of the pumps are controlled by setting a liquid level control system, which can realize the automatic operation of the wastewater treatment system.

[0038] The above shows and describes the basic principles, main features, and advantages of the present invention. Those of ordinary skill in the art should understand that the above embodiments do not limit the protection scope of the present invention in any form. Any technical solutions obtained by means of equivalent replacement and the like fall within the protection scope of the present invention. The parts not involved in the present invention are the same as or can be implemented by the prior art.

Claims

1. A method for treating electroplating nickel-containing wastewater, characterized in that, It includes a wastewater collection system, a pretreatment system, a separation system, a concentration system, an ultra-concentration system, and a sludge treatment system; the wastewater collection system includes a wastewater collection tank (1) and a collection tank lift pump (2); the pretreatment system includes a microfiltration and concentration water tank (3), a microfiltration circulation pump (4), a microfiltration membrane device (5), a microfiltration product water tank (6), a microfiltration product water tank booster pump (7), and a carbon filter (8); the separation system includes a security filter (9), a separation high-pressure pump (10), a separation device (11), a fresh water tank (12), and a fresh water reuse pump (13); the concentration system includes a concentration water tank (14), a concentration high-pressure pump (15), and a concentration device (16); the ultra-concentration system includes an ultra-concentration water tank (17), an ultra-concentration high-pressure pump (18), an ultra-concentration device (19), an ultra-concentration booster pump (20), a concentrated liquid collection tank (21), and a concentrated liquid reuse pump (22); the sludge treatment system includes a sludge tank (23), a sludge pump (24), and a sludge dehydrator (25).The water outlet of the wastewater collection tank (1) is connected to the water inlet of the collection tank lift pump (2); the water outlet of the collection tank lift pump (2) is connected to the water inlet of the microfiltration and concentration water tank (3); the water outlet of the microfiltration and concentration water tank (3) is connected to the water inlet of the microfiltration circulation pump (4); the water outlet of the microfiltration circulation pump (4) is respectively connected to the water inlets of the microfiltration membrane device (5) and the sludge tank (23); the fresh water outlet of the microfiltration membrane device (5) is connected to the water inlet of the microfiltration product water tank (6), and the concentrated water outlet of the microfiltration membrane device (5) is connected to the water inlet of the microfiltration and concentration water tank (3); the water outlet of the microfiltration product water tank (6) is connected to the water inlet of the microfiltration product water tank lift pump (7); the water outlet of the microfiltration product water tank booster pump (7) is connected to the water inlet of the carbon filter (8); the water outlet of the carbon filter (8) is connected to the water inlet of the security filter (9); the water outlet of the security filter (9) is connected to the water inlet of the separation high-pressure pump (10); the fresh water outlet of the separation device (11) is connected to the water inlet of the fresh water tank (12), and the concentrated water outlet of the separation device (11) is connected to the water inlet of the concentration water tank (14); the water outlet of the concentration water tank (14) is connected to the water inlet of the concentration high-pressure pump (15); the water outlet of the concentration high-pressure pump (15) is connected to the water inlet of the concentration device (16); the fresh water outlet of the concentration device (16) is connected to the water inlet of the microfiltration product water tank (6), and the concentrated water outlet of the concentration device (16) is connected to the water inlet of the ultra-concentration water tank (17); the water outlet of the ultra-concentration water tank (17) is respectively connected to the water inlets of the ultra-concentration high-pressure pump (18) and the ultra-concentration water tank booster pump (20); the water outlet of the ultra-concentration high-pressure pump (18) is connected to the water inlet of the ultra-concentration device (19); the fresh water outlet of the ultra-concentration device (19) is connected to the water inlet of the concentration water tank (14), and the concentrated water outlet of the ultra-concentration device (19) is connected to the water inlet of the ultra-concentration water tank (17); the water outlet of the fresh water tank (12) is connected to the water inlet of the fresh water reuse pump (13); the water outlet of the fresh water reuse pump (13) is connected to the water washing tank of the production line; the water outlet of the ultra-concentration water tank booster pump (20) is connected to the water inlet of the concentrated liquid collection tank (21); the water outlet of the concentrated liquid collection tank (21) is connected to the water inlet of the concentrated liquid reuse pump (22); the water outlet of the concentrated liquid reuse pump (22) is connected to the electroplating mother tank of the production line; the water outlet of the sludge tank (23) is connected to the water inlet of the sludge pump (24); the water outlet of the sludge pump (24) is connected to the water inlet of the sludge dehydrator (25).

2. The electroplating nickel-containing wastewater treatment method according to claim 1, wherein A foot valve is provided at the bottom of the inlet pipeline of the collection tank lift pump (2).

3. A method for treating nickel-containing electroplating wastewater according to claim 1, characterized in that, The pretreatment system uses a microfiltration membrane device (5) and a carbon filter (8) to filter the wastewater.

4. A method for treating electroplating nickel-containing wastewater according to claim 1, characterized in that, The wastewater in the microfiltration concentration water tank (3) is sent into the microfiltration membrane device (5) by the microfiltration circulation pump (4) for circulating filtration. The final waste liquid in the microfiltration concentration water tank (3) is regularly discharged into the sludge treatment system through the microfiltration circulation pump (4) for treatment.

5. A method for treating electroplating nickel-containing wastewater according to claim 1, characterized in that, The separation device (11) uses a brackish water desalination reverse osmosis membrane to separate the wastewater; both the concentration device (16) and the ultra-concentration device (19) use a D-series nanofiltration membrane to concentrate the wastewater.

6. The electroplating nickel-containing wastewater treatment method according to claim 1, wherein, The fresh water tank (12) is used to collect the fresh water of the separation device (11). When the conductivity reaches below 200 us / cm, it can be reused in the water washing tank of the electroplating production line.

7. A method for treating nickel-containing electroplating wastewater according to claim 1, characterized in that, The wastewater in the ultra-concentration water tank (17) is sent into the ultra-concentration device (19) by the ultra-concentration high-pressure pump (18) for circulating concentration treatment. The concentration of nickel in the concentrated liquid is not less than 40 g / L, and finally it is sent into the concentrated liquid collection tank (21) through the ultra-concentration water tank booster pump (20) for collection and reused in the electroplating mother tank of the production line.

8. A method for treating electroplating nickel-containing wastewater according to claim 1, characterized in that, Both the fresh water reuse pump (13) and the concentrated liquid reuse pump (22) use variable frequency constant pressure pumps. The fresh water reuse pump (13) is provided with a ball valve on its outlet pipeline and near the water washing tank of the production line to control the recycled water from entering the water washing tank. When the ball valve is opened, the internal pressure of the pipeline decreases, and the fresh water reuse pump (13) is turned on, and the fresh water is sent into the water washing tank. When the ball valve is closed, the internal pressure of the pipeline rises, and the fresh water reuse pump (13) is turned off, and the fresh water stops being sent into the water washing tank. The concentrated liquid reuse pump (22) is provided with a ball valve on its outlet pipeline and near the electroplating mother tank of the production line to control the bath liquid from entering the electroplating mother tank. When the ball valve is opened, the internal pressure of the pipeline decreases, and the concentrated liquid reuse pump (22) is turned on, and the concentrated liquid is sent into the electroplating mother tank. When the ball valve is closed, the internal pressure of the pipeline rises, and the concentrated liquid reuse pump (22) is turned off, and the concentrated liquid stops being sent into the electroplating mother tank.

9. A method for treating electroplating nickel-containing wastewater according to claim 1, characterized in that, The sewage generated by the sludge dewatering machine (25) flows back to the wastewater collection tank (1), and the generated sludge is entrusted to a professional agency for disposal as hazardous waste.

10. A method for treating electroplating nickel-containing wastewater according to claim 1, characterized in that, A liquid level control system is set in the wastewater collection tank (1) to control the start and stop of the collection tank lift pump (2). When the liquid level is high, the collection tank lift pump (2) starts; when the liquid level is low, the collection tank lift pump (2) stops. A liquid level control system is set in the microfiltration and concentration water tank (3) to control the start and stop of the microfiltration circulation pump (4). When the liquid level is high, the microfiltration circulation pump (4) turns on; when the liquid level is low, the microfiltration circulation pump (4) stops. A liquid level control system is set in the microfiltration product water tank (6) to control the start and stop of the microfiltration product water tank booster pump (7) and the separation high-pressure pump (10). When the liquid level is high, the microfiltration product water tank booster pump (7) and the separation high-pressure pump (10) are turned on in sequence; when the liquid level is low, the separation high-pressure pump (10) and the microfiltration product water tank booster pump (7) stop in sequence. A liquid level control system is set in the fresh water tank (12) to control the start and stop of the separation high-pressure pump (11) and the fresh water reuse pump (13). When the liquid level is high, the separation high-pressure pump (11) stops; when the liquid level is low, the fresh water reuse pump (13) stops. A liquid level control system is set in the concentrated water tank (14) to control the start and stop of the concentrated water high-pressure pump (15). When the liquid level is high, the concentrated water high-pressure pump (15) turns on; when the liquid level is low, the concentrated water high-pressure pump (15) stops. A liquid level gauge is set in the ultra-concentrated water tank (17) to control the start and stop of the ultra-concentrated water high-pressure pump (18) and the ultra-concentrated water tank booster pump (20). When the liquid level is high, the ultra-concentrated water high-pressure pump (18) turns on; when the liquid level is low, the ultra-concentrated water high-pressure pump (18) and the ultra-concentrated water tank booster pump (20) stop. A liquid level control system is set in the concentrated liquid collection tank (21) to control the start and stop of the ultra-concentrated water tank booster pump (20) and the concentrated liquid reuse pump (22). When the liquid level is high, the ultra-concentrated water tank booster pump (20) stops; when the liquid level is low, the concentrated liquid reuse pump (22) stops. A liquid level control system is set in the sludge tank (23) to control the start and stop of the sludge pump (24). When the liquid level is high, the sludge pump (24) turns on; when the liquid level is low, the sludge pump (24) stops.

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