Complete equipment for recycling heavy metal wastewater

Abstract

The utility model relates to the technical field of heavy metal wastewater treatment, in particular to complete equipment for recycling heavy metal wastewater. The equipment comprises a nanofiltration separation device, the nanofiltration separation device is connected with a low-concentration wastewater storage pool through a pipeline so that low-concentration heavy metal wastewater can be conveyed into the nanofiltration separation device to be subjected to nanofiltration treatment, the nanofiltration separation device comprises a nanofiltration membrane separation concentrated water chamber, and the nanofiltration membrane separation concentrated water chamber is communicated with a high-concentration wastewater storage pool through a pipeline. The high-concentration heavy metal wastewater is conveyed into the high-concentration wastewater storage pool to be stored; the device is connected with a high-concentration wastewater storage pool through a pipeline and placed into an electro-deposition tank, the high-concentration heavy metal wastewater subjected to nanofiltration treatment is fed into the electro-deposition tank for electro-deposition treatment through the electro-deposition tank, and the electro-deposition tank is further connected with a low-concentration wastewater storage pool through a pipeline. By utilizing the equipment disclosed by the utility model, treated heavy metal wastewater can be recycled, zero emission is realized, and heavy metals in water with all concentrations can be effectively recovered.

Description

Technical Field

[0001] This utility model relates to the field of heavy metal wastewater treatment technology, specifically to a complete set of equipment for the resource utilization of heavy metal wastewater. Background Technology

[0002] Heavy metal wastewater mainly originates from industries such as mining, metallurgy, electronics, electroplating, and machining. These industries generate large amounts of low- to high-concentration heavy metal wastewater daily. Untreated discharge not only severely harms soil and water environments but also wastes valuable heavy metal and water resources. If heavy metals can be recovered while ensuring the effluent meets standards for recycling and achieving zero discharge, not only will the wastewater pollution problem be solved, but the resource shortage problem can also be addressed to some extent.

[0003] Currently, the main technologies for treating heavy metal wastewater are nanofiltration membrane separation and micro-electrolysis. Nanofiltration membrane separation requires a nanofiltration membrane separation device, which includes a nanofiltration raw water tank, a water pump, and a nanofiltration membrane module. The wastewater containing heavy metals is pumped into the nanofiltration membrane module for concentration and separation, recovering heavy metals while discharging treated water that meets standards. However, this nanofiltration membrane separation device is only suitable for treating wastewater with a concentration <300 mg / L because the membrane is easily fouled, leading to excessively high system pressure and leakage. Micro-electrolysis, on the other hand, requires the selection of suitable electrodes and an electrolytic cell. This device requires a raw water tank, an electrolytic cell, a power supply, electrodes, and an effluent tank. Wastewater is pumped into the electrolytic module, and the concentration is reduced through electrochemical principles to achieve purification. This device is suitable for treating wastewater with a concentration >400 mg / L, but its treatment efficiency is low. Since the wastewater treatment devices mentioned above have limitations on the concentration of wastewater that can be treated and cannot achieve zero wastewater discharge, there is an urgent need for a complete set of heavy metal wastewater resource recovery equipment that can treat heavy metal wastewater of any concentration and achieve zero wastewater discharge. Summary of the Invention

[0004] The purpose of this invention is to overcome the aforementioned problems in the existing technology and to provide a complete set of equipment for the resource recovery of heavy metal wastewater that not only enables the treated heavy metal wastewater to be recycled and reused, achieving zero discharge, but also effectively recovers heavy metals from water of all concentrations.

[0005] This utility model provides a complete set of equipment for the resource utilization of heavy metal wastewater, including: a nanofiltration separation device, which is connected to a low-concentration wastewater storage tank via a pipeline, so that the low-concentration heavy metal wastewater is sent to the nanofiltration separation device for nanofiltration treatment; the nanofiltration separation device includes a nanofiltration membrane separation concentrate chamber, which is connected to a high-concentration wastewater storage tank via a pipeline, so that the nanofiltration-treated high-concentration heavy metal wastewater is sent to the high-concentration wastewater storage tank for storage; and further includes:

[0006] The electrodeposition tank is connected to a high-concentration wastewater storage tank via pipelines, so that the high-concentration heavy metal wastewater after nanofiltration is sent into the electrodeposition tank for electrodeposition treatment. The electrodeposition tank is also connected to a low-concentration wastewater storage tank via pipelines, so that the low-concentration heavy metal wastewater after electrodeposition treatment is sent into the low-concentration wastewater storage tank for storage.

[0007] Preferably, the high-concentration wastewater storage tank is connected to a high-concentration wastewater inlet pipe.

[0008] Preferably, the low-concentration wastewater storage tank is connected to a low-concentration heavy metal wastewater conveying pipe.

[0009] Preferably, all of the pipelines are equipped with valves.

[0010] Preferably, the pipeline is equipped with a variable frequency pump.

[0011] Preferably, both the high-concentration wastewater storage tank and the low-concentration wastewater storage tank are equipped with stirring equipment.

[0012] Preferably, the electrodeposition tank is connected to an electrodeposited heavy metal discharge pipe.

[0013] Preferably, the nanofiltration separation device further includes a nanofiltration membrane separation desalination chamber, and the nanofiltration membrane separation desalination chamber is connected to a nanofiltration membrane separation desalination chamber outlet pipeline.

[0014] Preferably, all of the pipelines are equipped with flow meters.

[0015] Preferably, all of the pipelines are made of corrosion-resistant materials.

[0016] Compared with the prior art, the beneficial effects of this utility model are:

[0017] The complete set of heavy metal wastewater resource recovery equipment provided by this utility model not only enables the recycling of treated heavy metal wastewater, achieving zero discharge, but also effectively recovers heavy metals from all concentrations of water. This equipment treats high-concentration heavy metal wastewater using an electrodeposition tank, effectively recovering heavy metals while avoiding the problems of shortened membrane life and low heavy metal recovery rates caused by nanofiltration separation devices. The low-concentration heavy metal wastewater after electrodeposition is sent to a nanofiltration membrane separation device for further treatment, avoiding environmental pollution caused by the low-concentration heavy metal wastewater discharged from the electrodeposition tank. Furthermore, the low-concentration heavy metal wastewater discharged from the electrodeposition tank still contains a small amount of heavy metals, which are then concentrated and separated by the nanofiltration membrane separation device. The concentrated high-concentration heavy metal wastewater is recycled and reused, undergoing another electrodeposition treatment in the electrodeposition tank. The freshwater discharged from the nanofiltration membrane separation desalination chamber after separation can be reused, achieving zero discharge and resource recovery of heavy metal wastewater. It is applicable to the treatment of heavy metal wastewater of any concentration; no chemical agents are required during the treatment process, and no secondary pollutants such as sludge are generated. While recovering heavy metals, it can also make the treated effluent meet the standards for recycling. Attached Figure Description

[0018] Figure 1 This is a diagram of the device according to this utility model.

[0019] Explanation of reference numerals in the attached figures:

[0020] 1. High-concentration wastewater inlet pipe; 2. Low-concentration heavy metal wastewater conveying pipe; 3. High-concentration wastewater storage tank; 4. Low-concentration wastewater storage tank; 5. Electrodeposition tank; 6. Nanofiltration separation device; 7. Electrodeposited heavy metal discharge pipe; 8. Nanofiltration membrane separation freshwater chamber outlet pipeline. Detailed Implementation

[0021] The following is in conjunction with the appendix Figure 1 The specific embodiments of this utility model are described in detail below, but it should be understood that the protection scope of this utility model is not limited to the specific embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without inventive effort are within the protection scope of this utility model.

[0022] This invention enables the recycling and reuse of treated heavy metal wastewater, achieving zero discharge, and also effectively recovers heavy metals from water of all concentrations.

[0023] This utility model provides a complete set of equipment for the resource utilization of heavy metal wastewater. The equipment includes: a nanofiltration separation device 6, which is connected to a low-concentration wastewater storage tank 4 via a pipeline, so that the low-concentration heavy metal wastewater is sent to the nanofiltration separation device 6 for nanofiltration treatment; the nanofiltration separation device 6 includes a nanofiltration membrane separation concentrate chamber, which is connected to a high-concentration wastewater storage tank 3 via a pipeline, so that the nanofiltration-treated high-concentration heavy metal wastewater is sent to the high-concentration wastewater storage tank 3 for storage; and further includes:

[0024] The electrodeposition tank 5 is connected to the high-concentration wastewater storage tank 3 via pipelines, so that the high-concentration heavy metal wastewater after nanofiltration is sent into the electrodeposition tank 5 for electrodeposition treatment. The electrodeposition tank 5 is also connected to the low-concentration wastewater storage tank 4 via pipelines, so that the low-concentration heavy metal wastewater after electrodeposition treatment is sent into the low-concentration wastewater storage tank 4 for storage.

[0025] Specifically, a high-concentration wastewater inlet pipe 1 is connected to the high-concentration wastewater storage tank 3, and the high-concentration wastewater inlet pipe 1 is used to supply high-concentration wastewater to the high-concentration wastewater storage tank 3.

[0026] Specifically, a low-concentration wastewater storage tank 4 is connected to a low-concentration heavy metal wastewater conveying pipe 2 for the discharge of low-concentration heavy metal wastewater.

[0027] Specifically, valves are installed on all pipelines. These valves control the inlet and outlet water, extending the residence time of water in each device and enhancing treatment efficiency.

[0028] Specifically, a variable frequency pump is installed on the pipeline. The pump's operating status is adjusted according to actual needs, significantly reducing energy consumption. This reduces frequent pump start-ups and shutdowns, extends pump lifespan, and provides stable flow and pressure.

[0029] Specifically, both the high-concentration wastewater storage tank 3 and the low-concentration wastewater storage tank 4 are equipped with stirring devices to mix the wastewater and stabilize its concentration.

[0030] Specifically, the electrodeposition tank 5 is connected to an electrodeposited heavy metal discharge pipe 7.

[0031] Specifically, the nanofiltration separation device 6 also includes a nanofiltration membrane separation desalination chamber, and a nanofiltration membrane separation desalination chamber outlet pipeline 8 is connected to the nanofiltration membrane separation desalination chamber.

[0032] Specifically, flow meters are installed on all pipelines. The flow rate is controlled by the flow meters, which in turn controls the hydraulic retention time, thereby improving wastewater treatment efficiency.

[0033] Specifically, all pipelines are made of corrosion-resistant materials. PP polypropylene water pipes are used, which have stable corrosion resistance, high temperature resistance, and are transparent with good electrical insulation.

[0034] Example 1

[0035] This embodiment mainly examines the treatment effect of the complete set of heavy metal wastewater resource utilization equipment provided by this utility model on high-concentration copper-containing wastewater.

[0036] like Figure 1 As shown, high-concentration copper-containing wastewater with a copper ion concentration >400 mg / L is gravity-fed at a flow rate of 4 L / h to an 80 L high-concentration wastewater storage tank 3. After 10 hours, it is pumped at a flow rate of 8 L / h into an electrodeposition tank 5 for electrolytic copper recovery. The voltage of the electrodeposition tank 5 is 2.5 V, the volume of the electrodeposition tank 5 is 4 L, and the hydraulic retention time of the wastewater is 0.5 h. The low-concentration copper-containing wastewater from the electrodeposition tank flows into an 80 L low-concentration wastewater storage tank 4 for storage. After 10 hours... The wastewater is then pumped into the nanofiltration separation device 6 at a flow rate of 4 L / h in the concentrated chamber and 4 L / h in the dilute chamber for separation. The nanofiltration membrane separation device 6 has 200 membrane pairs and an applied voltage of 50V. The effluent from the dilute chamber is recycled through the nanofiltration membrane separation effluent pipeline, while the effluent from the concentrated chamber flows into the high-concentration wastewater storage tank 3 and is thoroughly mixed with the high-concentration copper-containing wastewater transported by the high-concentration wastewater inlet pipe 1 before entering the next cycle. After continuous and stable operation, samples are taken every half hour at the inlet and outlet of the electrodeposition tank 5, the inlet of the nanofiltration separation device 6, the outlet of the concentrated chamber, and the outlet of the dilute chamber of the nanofiltration separation device 6. Table 1 shows the test results of the equipment of this utility model under the process conditions.

[0037] Table 1 shows the experimental results of treating high-concentration wastewater using a combined electrodeposition-nanofiltration membrane separation technology (concentration refers to copper ion concentration, unit: mg / L; conductivity unit: μS / cm).

[0038]

[0039] Example 2

[0040] This embodiment mainly examines the treatment effect of the complete set of heavy metal wastewater resource utilization equipment provided by this utility model on low-concentration copper-containing wastewater.

[0041] like Figure 1As shown, low-concentration copper-containing wastewater with a copper ion concentration <300 mg / L is gravity-fed at a flow rate of 4 L / h to an 80 L low-concentration wastewater storage tank 4. After 10 hours, it is pumped into a nanofiltration separation device 6 at a flow rate of 4 L / h in both the concentrate chamber and the dilute chamber for separation. The nanofiltration separation device 6 has a membrane pair of 200 and an applied voltage of 40 V. The effluent from the dilute chamber of the nanofiltration membrane separation is recycled, while the effluent from the concentrate chamber of the nanofiltration membrane separation is recycled. Water flows into the high-concentration wastewater storage tank 3; after 10 hours, it is pumped into the electrodeposition tank 5 at a flow rate of 4L / h for copper recovery through electrodeposition. The voltage of the electrodeposition tank 5 is 2.0V, the volume of the electrodeposition tank 5 is 4L, and the hydraulic retention time of the wastewater is 1h. The low-concentration copper-containing wastewater from the electrodeposition tank flows into the 80L low-concentration wastewater storage tank 4, where it is thoroughly mixed and homogenized with the low-concentration heavy metal wastewater transported by the low-concentration heavy metal wastewater transport pipe before entering the next cycle. After continuous and stable operation, samples are taken every half hour at the inlet and outlet of the electrodeposition tank 5, the inlet, the concentrated chamber outlet, and the dilute chamber outlet of the nanofiltration separation device 6. Table 2 shows the test results of the equipment of this utility model under the process conditions.

[0042] Table 2 shows the experimental results of treating low-concentration wastewater using the combined electrodeposition-nanofiltration membrane separation technology (concentration refers to copper ion concentration, unit mg / L, conductivity unit μS / cm).

[0043]

[0044] Example 3

[0045] This embodiment mainly examines the effect of the device of this utility model in simultaneously treating high-concentration copper-containing wastewater and low-concentration copper-containing wastewater.

[0046] like Figure 1As shown, high-concentration copper-containing wastewater with a copper ion concentration >400 mg / L is gravity-fed to an 80 L high-concentration wastewater storage tank 3 at a flow rate of 4 L / h, and low-concentration copper-containing wastewater with a copper ion concentration <300 mg / L is gravity-fed to an 80 L low-concentration wastewater storage tank 4 at a flow rate of 4 L / h. After 10 hours, the wastewater in the high-concentration wastewater storage tank 3 is pumped to an electrodeposition tank 5 at a flow rate of 4 L / h for copper recovery by electrodeposition. The voltage of the electrodeposition tank 5 is 2.0 V, the volume of the electrodeposition tank 5 is 4 L, and the hydraulic retention time of the wastewater is 1 h. The low-concentration copper-containing wastewater in the low-concentration wastewater storage tank 4 is pumped to a nanofiltration separation device 6 at a flow rate of 4 L / h in the concentration chamber and 4 L / h in the dilute chamber for separation treatment. The membrane pair of the nanofiltration separation device 6 is 200, and the applied voltage of the nanofiltration separation device 6 is 40 V. The treated low-concentration copper-containing wastewater from the electrodeposition tank flows into the low-concentration wastewater storage tank 4, where it is thoroughly mixed with the low-concentration copper-containing wastewater before entering the next cycle. The effluent from the dilute chamber of the nanofiltration separation device 6 is recycled, while the effluent from the concentrate chamber of the nanofiltration separation device 6 flows into the high-concentration wastewater storage tank 3, where it is thoroughly mixed with the high-concentration copper-containing wastewater before entering the next cycle. After continuous and stable operation, samples are taken every half hour from the inlet and outlet of the electrodeposition tank 5, the inlet, concentrate chamber outlet, and dilute chamber outlet of the nanofiltration separation device 6, respectively. Table 3 shows the test results of the equipment of this utility model under these process conditions.

[0047] Table 3 shows the experimental results of treating high / low concentration wastewater using the combined electrodeposition-nanofiltration membrane separation technology (concentration refers to copper ion concentration, unit mg / L, conductivity unit μS / cm).

[0048]

[0049] Example 1 demonstrates the treatment effect of the novel heavy metal wastewater resource recovery equipment on high-concentration copper-containing wastewater. Example 2 shows the treatment of low-concentration wastewater using the same equipment. Example 3 presents an experiment on the simultaneous treatment of high-concentration and low-concentration wastewater. Table 1 shows the treatment effect on high-concentration (504.31 mg / L) wastewater. )Copper-containing wastewater can be treated to a concentration of 0.38 mg / L in freshwater, with a conductivity of 69.5 μS / cm. Table 2 shows that for treating low-concentration (281.16 mg / L) copper-containing wastewater, the concentration can be reduced to 1.25 mg / L in freshwater, with a conductivity of 144.5 μS / cm. Table 3 shows that when simultaneously treating high-concentration (446.51 mg / L) and low-concentration (165.33 mg / L) wastewater, the effluent concentration is reduced to 0.72 mg / L, with a conductivity of 95.6 μS / cm. In Examples 1-3, all water quality indicators meet the reuse standards, the effluent has a low concentration of metal ions, and a high water reuse rate is achieved, significantly alleviating the water shortage problem in electroplating. The results confirm that this invention is effective in treating heavy metal wastewater of all concentrations, achieving zero discharge and resource recovery of heavy metal wastewater.

[0050] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A complete set of heavy metal wastewater resource utilization equipment, comprising: The nanofiltration separation device (6) is connected with the low-concentration wastewater storage tank (4) through a pipeline, so that the low-concentration heavy metal wastewater is sent to the nanofiltration separation device (6) for nanofiltration treatment, and the nanofiltration membrane separation concentrated water chamber is characterized in that the nanofiltration membrane separation concentrated water chamber is communicated with the high-concentration wastewater storage tank (3) through a pipeline, so that the high-concentration heavy metal wastewater treated by nanofiltration is sent to the high-concentration wastewater storage tank (3) for storage; and the nanofiltration separation device (6) further comprises: The electrodeposition tank (5) is connected with the high-concentration wastewater storage tank (3) through a pipeline, so that the high-concentration heavy metal wastewater treated by nanofiltration is sent to the electrodeposition tank (5) for electrodeposition treatment, and the electrodeposition tank (5) is also connected with the low-concentration wastewater storage tank (4) through a pipeline, so that the low-concentration heavy metal wastewater treated by electrodeposition is sent to the low-concentration wastewater storage tank (4) for storage.

2. The complete set of equipment for heavy metal wastewater resource recovery according to claim 1, characterized in that, The high-concentration wastewater storage tank (3) is connected with a high-concentration wastewater inlet pipe (1).

3. The complete set of equipment for heavy metal wastewater resource recovery according to claim 2, characterized in that, The low-concentration wastewater storage tank (4) is connected with a low-concentration heavy metal wastewater conveying pipe (2).

4. The complete set of equipment for heavy metal wastewater resource recovery according to claim 3, characterized in that, Valves are arranged on all the pipelines.

5. The complete set of equipment for heavy metal wastewater resource recovery according to claim 1, characterized in that, Variable frequency pumps are arranged on the pipelines.

6. The complete set of equipment for heavy metal wastewater resource recovery according to claim 1, characterized in that, The high-concentration wastewater storage tank (3) and the low-concentration wastewater storage tank (4) are both provided with stirring equipment.

7. The complete set of equipment for heavy metal wastewater resource recovery according to claim 1, characterized in that, The electrodeposition tank (5) is connected with an electrodeposition heavy metal discharge pipe (7).

8. The complete set of equipment for heavy metal wastewater resource recovery according to claim 1, characterized in that, The nanofiltration separation device (6) further comprises a nanofiltration membrane separation fresh water chamber, and the nanofiltration membrane separation fresh water chamber is connected with a nanofiltration membrane separation fresh water chamber outlet pipeline (8).

9. The heavy metal wastewater resource utilization complete equipment according to claim 1, characterized in that, Flow meters are arranged on all the pipelines.

10. The heavy metal wastewater resource utilization complete equipment according to claim 1, characterized in that, All the pipelines are made of corrosion-resistant materials.

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