Wastewater treatment device for realizing zero discharge of nickel ions in electroplating wastewater

Abstract

The utility model relates to the technical field of sewage treatment, and particularly discloses a wastewater treatment device for realizing zero discharge of nickel ions in electroplating wastewater, which comprises a wastewater collection tank, a complex breaking reaction tank, a chemical reaction tank and an ultrafiltration membrane filter tank which are sequentially arranged, lifting to a complex breaking reaction tank through a lifting pump; a complex breaking reaction stirrer is arranged in the complex breaking reaction tank; the complex breaking reaction tank is communicated with the chemical reaction tank through a top self-flowing groove, and the chemical reaction tank is externally connected with a PAC dosing device, a PAM dosing device and a liquid caustic soda dosing device; the chemical reaction tank is communicated with the ultrafiltration membrane filtering tank through a top self-flowing groove. The device is specially used for wastewater treatment for realizing zero discharge of nickel ions in electroplating wastewater, a chemical complex breaking process section is arranged in the wastewater treatment device, and meanwhile, an ultrafiltration membrane filtration mode is adopted, so that final wastewater discharge can be realized, and the operation and treatment cost is relatively low.

Description

TECHNICAL FIELD

[0001] The utility model relates to sewage treatment technical field, concretely relates to a wastewater treatment device for realizing zero discharge of nickel ions in electroplating wastewater. BACKGROUND

[0002] In today's society, for such nickel-containing wastewater, in the case of relatively stringent treatment requirements, heavy metal capture agents are usually used to induce chemical reactions to achieve precipitation treatment. However, when nickel exists in the form of complex compounds, even if heavy metal capture agents are used, it is difficult to achieve the desired precipitation effect. This easily leads to nickel concentration exceeding the discharge standard in the wastewater discharge link. Moreover, given the high cost of using heavy metal capture agents, enterprises face great challenges in cost control and are difficult to maintain this treatment method in the long term. SUMMARY

[0003] The utility model provides a wastewater treatment device for realizing zero discharge of nickel ions in electroplating wastewater is provided with chemical breakage process section, adopts the mode of ultrafiltration membrane filtration simultaneously, so that the final wastewater discharge can be realized, and the operation disposal cost is lower.

[0004] The utility model solves the above technical problem through the following technical scheme:

[0005] A wastewater treatment device for realizing zero discharge of nickel ions in electroplating wastewater, comprising wastewater collection pool, breakage reaction pool, chemical reaction pool and ultrafiltration membrane filtration pool arranged in sequence, the wastewater collection pool is connected with breakage reaction pool pipeline, and is lifted to breakage reaction pool through the lifting pump, the breakage reaction pool is connected with ferrous sulfate dosing device, sulfuric acid dosing device and hydrogen peroxide dosing device, and breakage reaction agitator is arranged in the breakage reaction pool, the breakage reaction pool is communicated with chemical reaction pool through top self-flowing groove, and the chemical reaction pool is connected with PAC dosing device, PAM dosing device and liquid alkali dosing device, the chemical reaction pool is communicated with ultrafiltration membrane filtration pool through top self-flowing groove.

[0006] In a specific embodiment, the ferrous sulfate dosing device includes an online metering pump, a pH sensor and a flow meter, the added sodium sulfide concentration is 0.1%-0.5%(w / v), and the mixing residence time is 5-15min.

[0007] In a specific embodiment, the device further includes a PLC automatic control system, which is electrically connected with the pH sensor, metering pump and flow meter in the ferrous sulfate dosing device.

[0008] In a specific embodiment, the ultrafiltration membrane filtration pool includes at least two series nanofiltration membrane assemblies, the membrane pore size is between 0.5-2nm, and the operating pressure is 1.0-2.5MPa.

[0009] In some embodiments, all pipes, containers and valves in contact with the wastewater are made of polytetrafluoroethylene, polyethylene or acid and alkali resistant stainless steel.

[0010] The utility model discloses the beneficial effect lies in:

[0011] 1. The device can not use expensive heavy metal capture agent reagent, and the operation cost is low,

[0012] 2. The ultrafiltration membrane filtration form is adopted to replace the sedimentation tank, and the wastewater treatment equipment and facilities are small in land occupation scale.

[0013] 3. The operation flexibility is high, and the automatic operation of the complete set of devices can be realized. BRIEF DESCRIPTION OF DRAWINGS

[0014] In order to more clearly illustrate the technical scheme in the utility model embodiment or prior art, the following will briefly introduce the drawings needed to be used in the embodiment or prior art description, and obviously, the drawings in the following description are only the embodiments of the utility model, and for those skilled in the art, other drawings can be obtained without creative labor on the premise of providing the drawings.

[0015] Figure 1 The structure schematic view of the utility model is shown as the structure schematic view of the utility model,

[0016] In the drawings, 1 is a lifting pump, 2 is an ultrafiltration membrane drainage pump, 3 is a PAC dosing device, 4 is a PAM dosing device, 5 is a ferrous sulfate dosing device, 6 is a sulfuric acid dosing device, 7 is a liquid alkali dosing device, 8 is a hydrogen peroxide dosing device, 10 is a wastewater inlet, 11 is a wastewater collection tank, 12 is a breakage reaction tank, 13 is a breakage reaction stirrer, 14 is a chemical reaction tank, 15 is a chemical reaction stirrer, 16 is an ultrafiltration membrane filter tank, 17 is an ultrafiltration membrane, and 18 is a wastewater discharge port. DETAILED DESCRIPTION

[0017] The technical scheme in the utility model embodiment will be described clearly and completely in combination with the drawings in the utility model embodiment, and obviously, the described embodiments are only part of the embodiments of the utility model, rather than all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by those skilled in the art without creative labor belong to the protection scope of the utility model.

[0018] Embodiment one

[0019] As Figure 1 shown, a wastewater treatment device for realizing zero discharge of nickel ions in electroplating wastewater includes a wastewater collection tank 11, a breakage reaction tank 12, a chemical reaction tank 14 and an ultrafiltration membrane filter tank 16. The process flow and parameters are as follows:

[0020] uniform water quality and quantity

[0021] Take the electroplating workshop wastewater as an example, the electroplating workshop produces nickel-containing wastewater which is collected by pipeline to wastewater collection tank 11, 2m 3 capacity, liquid level sensor and grid, automatic removal of suspended solids. The lift pump 1 raises the wastewater to 5m 3 / h flow to the complex breaking reaction tank 12.

[0022] complex breaking reaction (decomplexing)

[0023] The complex breaking reaction tank 12 has a volume of 3m 3 , equipped with a complex breaking reaction stirrer 13 (rotation speed 200 rpm).

[0024] External connection:

[0025] Ferrous sulfate dosing device 5: online metering pump, pH sensor, flow meter linkage control;

[0026] Sulfuric acid dosing device 6;

[0027] Hydrogen peroxide dosing device 8.

[0028] In this embodiment, the ferrous sulfate solution concentration is 10g / L, added at 0.2% (w / v), pH adjusted to 6.5, and mixed for 10min, to break the nickel complex and preliminary oxidation and precipitation.

[0029] Chemical reaction pretreatment

[0030] The complex breaking reaction tank 12 is provided with a self-flowing tank in the upper part, and the effluent flows into the chemical reaction tank 14. The chemical reaction tank 14 has a volume of 4m 3 , equipped with a stirrer and online pH / conductivity monitoring. External connection dosing device:

[0031] PAC (polyaluminum chloride) dosing device 3: flocculant, dosage 30mg / L;

[0032] PAM (polyacrylamide) dosing device 4: coagulant, dosage 1mg / L;

[0033] Liquid alkali (NaOH) dosing device 7: adjust pH to 7.0.

[0034] The flocculation reaction stops for 15min, generating flocs and removing part of the colloids and heavy metals.

[0035] Ultrafiltration membrane depth filtration

[0036] The treated water flows into the ultrafiltration membrane filtration tank 16 from the self-flowing tank in the upper part of the chemical reaction tank 14. The ultrafiltration unit is a two-stage series nanofiltration membrane assembly, with a single membrane area of 1.0m 2, membrane pore size 0.5-2nm, operating pressure 1.5MPa, cut off nickel ions and macromolecular organic matter. The concentration of nickel ions in the permeate is <0.1mg / L, realizing near-zero discharge.

[0037] PLC automatic control

[0038] The entire system is equipped with a PLC automatic control system. The PLC is linked with a pH sensor, a flow meter, a metering pump and an electric valve. The dosing amount and pump speed are adjusted in real time according to a preset PID algorithm. An alarm is triggered when the nickel concentration in the effluent is >0.5mg / L.

[0039] All pipes, pumps, valves, reaction tanks and membrane shells that are in contact with the wastewater are made of polytetrafluoroethylene (PTFE), polyethylene (PE) or acid and alkali resistant stainless steel (316L), ensuring long-term stable operation and corrosion resistance of the system.

[0040] The process flow is as follows: the nickel-containing wastewater enters the wastewater collection tank 11 through the water inlet 10, the water quality and quantity are uniform in the tank, and then the wastewater is lifted to the complex breaking reaction tank 13 by the wastewater lifting pump 1 in the collection tank. According to the concentration of each pollutant in the waste liquid, various dosing devices (ferrous sulfate dosing device 5, sulfuric acid dosing device 6, hydrogen peroxide dosing device 8) are used to dose into the complex breaking reaction tank 13, and the complex breaking reaction agitator 12 is opened for sufficient stirring and reaction. After the reaction is complete, it flows into the chemical reaction tank 14, various reagents (PAC dosing device 3, PAM dosing device 4, liquid alkali dosing device 7) are added into the chemical reaction tank 14, and the chemical reaction agitator 15 is opened for sufficient stirring and reaction. After the reaction is complete, it flows into the ultrafiltration membrane filter tank 16, and the clean water is pumped out from the ultrafiltration membrane 17 by the ultrafiltration membrane drainage pump 2, and finally discharged from the wastewater discharge port 18.

[0041] The embodiments in the specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the device disclosed in the embodiments, since it corresponds to the method disclosed in the embodiments, the description is relatively simple, and the related parts can be referred to the method part.

[0042] The above description of the disclosed embodiments enables a person skilled in the art to implement or use the utility. Various modifications to the embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the utility. Therefore, the utility will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A wastewater treatment device for achieving zero discharge of nickel ions from electroplating wastewater, characterized in that, The system comprises, in sequence: a wastewater collection tank, a complex-breaking reaction tank, a chemical reaction tank, and an ultrafiltration membrane filtration tank. The wastewater collection tank is connected to the complex-breaking reaction tank via pipeline, and the wastewater is pumped to the complex-breaking reaction tank via a lift pump. The complex-breaking reaction tank is externally connected to a ferrous sulfate dosing device, a sulfuric acid dosing device, and a hydrogen peroxide dosing device, and a complex-breaking reaction stirrer is installed inside the complex-breaking reaction tank. The complex-breaking reaction tank and the chemical reaction tank are connected via a top gravity flow channel, and the chemical reaction tank is externally connected to a PAC dosing device, a PAM dosing device, and a liquid alkali dosing device. The chemical reaction tank and the ultrafiltration membrane filtration tank are connected via a top gravity flow channel.

2. The apparatus according to claim 1, characterized in that, The ferrous sulfate dosing device includes an online metering pump, a pH sensor, and a flow meter. The concentration of sodium sulfide added is 0.1%–0.5% (w / v), and the mixing residence time is 5–15 min.

3. The apparatus according to claim 2, characterized in that, The device also includes a PLC automatic control system, which is electrically connected to the pH sensor, metering pump, and flow meter in the ferrous sulfate dosing device.

4. The apparatus according to claim 1, characterized in that, The ultrafiltration membrane filtration pool includes at least two nanofiltration membrane modules connected in series, with membrane pore sizes between 0.5 and 2 nm and operating pressures between 1.0 and 2.5 MPa.

5. The apparatus according to claim 1, characterized in that, All pipes, containers, and valves that come into contact with wastewater are made of polytetrafluoroethylene, polyethylene, or acid and alkali resistant stainless steel.

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