Heavy metal wastewater treatment and recycling device

Abstract

The utility model discloses a heavy metal wastewater treatment and recycling device which is characterized by mainly comprising a collecting tank, a lifting pump, a reaction tank, a circulating pump, a silicon carbide membrane device, a water producing tank, a raw water pump, a cloth bag filter, a security filter, a high-pressure pump, a nanofiltration device, a recycling water tank and a backwashing pump which are sequentially connected through pipelines, and a chromic acid recycling pool and a dehydrator are arranged. The equipment disclosed by the utility model is intensive, high in safety and reliability, and capable of recycling valuable heavy metals, reducing the amount of sludge generated by a common precipitation method, deeply treating and recycling the wastewater, effectively reducing the pollution of the heavy metal wastewater to the environment, really turning waste into wealth and realizing zero discharge of the wastewater.

Description

Technical Field

[0001] This utility model relates to the technical field of wastewater treatment, and in particular to a heavy metal wastewater treatment and reuse device. Background Technology

[0002] Heavy metal wastewater mainly originates from industries such as electroplating, mining, and chemicals. Heavy metal pollutants cannot be self-purified through degradation, but they can accumulate through the food chain. During this process, the difficult-to-decompose residual heavy metals released into the natural environment will continuously accumulate, polluting soil and groundwater. They are also highly susceptible to entering the human body through food, causing chronic poisoning and posing a significant threat to human health.

[0003] my country's wastewater treatment has officially moved from the stage of meeting discharge standards to the era of zero-discharge resource utilization. Traditional zero-discharge processes for heavy metal wastewater are based on traditional biological and physicochemical processes, with the addition of membrane and evaporation processes. However, due to limitations in technology and products, they generally suffer from the following drawbacks: high investment costs, low operating pressure and low concentration ratio of traditional membrane systems, resulting in large volumes of concentrated liquid and high investment costs for evaporation systems; poor biodegradability of heavy metal wastewater, long biological treatment time in traditional processes, and high investment and operating costs for the construction and operation of the treatment tanks; large amounts of waste salt and chemical sludge generated by traditional processes, which can only be disposed of as hazardous waste through outsourcing, resulting in high treatment costs and no resource utilization of valuable substances, only water resource recovery, with heavy metals in the wastewater only treated as hazardous waste.

[0004] The current excessively high investment and operating costs are difficult for enterprises to bear. Only economical and efficient zero-discharge processes that can achieve wastewater treatment and reuse can solve the urgent problem of sustainable development in the industry. Summary of the Invention

[0005] In order to overcome the technical problems existing in the field of existing technology, this utility model provides a heavy metal wastewater treatment and reuse device to address the shortcomings of existing processes.

[0006] To achieve the above objectives, this utility model adopts the following technical solution: The device mainly consists of a collection tank, a booster pump, a reaction tank, a circulation pump, a silicon carbide membrane device, a product water tank, a raw water pump, a bag filter, a security filter, a high-pressure pump, a nanofiltration device, a recycled water tank, and a backwash pump, all connected sequentially via pipelines. It also includes a chromic acid recycling tank and a dewatering machine. The silicon carbide membrane device has an inlet pipe, a product water pipe, a product discharge pipe, a recycling pipe, a concentrate pipe, and a concentrate discharge pipe. The product water pipe and the recycling pipe are connected in parallel and each is equipped with an electric valve. The concentrate pipe is connected to the reaction tank. The silicon carbide membrane device is connected to the product water tank via the product water pipe and to the chromic acid recycling tank via the recycling pipe. The reaction tank is connected to the inlet pipe of the silicon carbide membrane device via the circulation pump, and the inlet pipe is equipped with an electric inlet valve. The circulation pump is connected to the dewatering machine via a pipeline, which is also equipped with an electric valve.

[0007] Furthermore, the reaction tank is equipped with an alkali addition system, a water addition system, a hydrogen peroxide addition system, and a stirring system, as well as a pH meter, an online OPR meter, and a level gauge. After the heavy metal wastewater is pumped into the reaction tank, alkali is added to adjust the pH for precipitation. The precipitated wastewater is then concentrated using a silicon carbide membrane device. The resulting water enters a product water tank. The concentrated precipitate in the reaction tank is continuously washed and concentrated again. The washed precipitate is then reacted with hydrogen peroxide, and the product water is separated by a silicon carbide membrane device and sent to a chromic acid recycling tank. The precipitate returns to the reaction tank and is then pumped into a dewatering machine for dewatering. The resulting residue can be used for brick making.

[0008] Furthermore, the product water tank is equipped with a metal scavenging agent dosing system, a stirring system, and a level gauge. The waste liquid in the product water tank is then further treated by adding a metal scavenging agent, which reacts with other heavy metal ions that do not precipitate upon alkali addition to form insoluble substances. These insoluble substances are then filtered through a bag filter and further purified and reused via a nanofiltration device.

[0009] Furthermore, the reclaimed water tank is connected to the water supply system of the reaction tank via a pipeline, and the backwash pump outlet pipeline is connected to the silicon carbide membrane device and the nanofiltration device to backwash the filtration system.

[0010] The advantages of this device are as follows: it is compact, safe, and reliable; it can recycle valuable heavy metals; it reduces the amount of sludge produced by ordinary sedimentation methods; it can deeply treat and reuse wastewater, achieving zero discharge; it effectively reduces the pollution of heavy metal wastewater to the environment; it truly turns waste into treasure; and it greatly reduces the cost of production wastewater treatment. Attached Figure Description

[0011] Appendix Figure 1 This is a structural schematic diagram of one embodiment of the utility model.

[0012] In the diagram, 1. Collection tank; 2. Booster pump; 3. Reaction tank; 4. Circulation pump; 5. Silicon carbide membrane device; 6. Product water tank; 7. Raw water pump; 8. Bag filter; 9. Security filter; 10. High-pressure pump; 11. Nanofiltration device; 12. Reclaimed water tank; 13. Backwash pump; 14. Chromic acid reuse tank; 15. Dewatering machine; 16. Inlet pipe; 17. Product water pipe; 18. Product discharge pipe; 19. Reuse pipe; 20. Concentrate pipe; 21. Concentrate discharge pipe; 22. Electric valve; 23. Alkali addition system; 24. Water addition system; 25. Hydrogen peroxide addition system; 26. Stirring system; 27. pH meter; 28. OPR online instrument; 29. ​​Level gauge; 30. Metal scavenging agent dosing system. Detailed Implementation

[0013] The following is in conjunction with the appendix Figure 1 The specific embodiments of this utility model will be further described below.

[0014] like Figure 1 The diagram shows a chromium-containing electroplating wastewater treatment device. This device mainly consists of a collection tank 1, a booster pump 2, a reaction tank 3, a circulation pump 4, a silicon carbide membrane device 5, a product water tank 6, a raw water pump 7, a bag filter 8, a security filter 9, a high-pressure pump 10, a nanofiltration device 11, a recycled water tank 12, and a backwash pump 13, all connected sequentially by pipelines. It also includes a chromic acid recycling tank 14 and a dewatering machine 15. The silicon carbide membrane device 5 is equipped with an inlet pipe 16, a product water pipe 17, a product discharge pipe 18, a recycling pipe 19, and a concentration... Water pipe 20 and concentrate discharge pipe 21, the product water pipe 17 and reuse pipe 19 are connected in parallel and each is equipped with an electric valve 22. The concentrate pipe 20 is connected to the reaction tank 3. The silicon carbide membrane device 5 is connected to the product water tank 6 through the product water pipe 17 and to the chromic acid reuse tank 14 through the reuse pipe 19. The reaction tank 3 is connected to the inlet water pipe 16 of the silicon carbide membrane device 5 through the circulation pump 4. The inlet water pipe 16 is equipped with an inlet electric valve 22. The circulation pump 4 is connected to the dewatering machine 15 through a pipeline, which is also equipped with an electric valve 22. The reaction tank 3 is equipped with an alkali addition system 23, a water addition system 24, a hydrogen peroxide addition system 25 and a stirring system 26, and is equipped with a pH meter 27, an OPR online meter 28 and a level gauge 29. The product water tank 6 is equipped with a metal scavenging agent dosing system 30, a stirring system 26 and a level gauge 29.

[0015] The working process of this device is as follows: Heavy metal wastewater in collection tank 1 is first pumped to reaction tank 3 by lift pump 2. After reaching the set liquid level, lift pump 2 is turned off, and stirring device 26 and alkali addition system 23 are turned on. The pH value is monitored, and alkali addition system 23 is stopped after reaching the set range. After reacting for about half an hour, circulation pump 4 is turned on. The precipitated wastewater undergoes solid-liquid separation through silicon carbide membrane device 5. Electric valve 22 of product water pipe 17 is opened, and electric valve 22 of return pipe 19 is closed. Product water enters product water tank 6. Water addition system 24 is turned on to allow the precipitated wastewater to pass through. After cleaning and concentration, the water supply system 24 is closed, and the hydrogen peroxide supply system 25 is opened for reaction. The electric valve 22 of the product water pipe 17 is closed, and the electric valve 22 of the return pipe 19 is opened. The clear liquid separated by the silicon carbide membrane device 5 enters the chromic acid return tank 14, and the precipitate returns to the reaction tank 3 for concentration. The electric valve 22 on the inlet water pipe 16 of the silicon carbide membrane device 5 is closed, and the electric valve 22 on the pipe connecting to the dewatering machine 15 is opened. The precipitate enters the dewatering machine 15 through the circulation pump 4 for dewatering. The resulting residue can be used for brick making. The waste liquid enters the product water tank 6, and the metal scavenging agent dosing system 30 and the stirring system 26 are opened. By adding the metal scavenging agent, other heavy metal ions that do not precipitate after alkali addition react to generate insoluble substances, which enter the bag filter 8 through the raw water pump 7 for filtration, and then enter the nanofiltration device 11 for water purification after passing through the security filter 9 and the high-pressure pump 10. The product water of the nanofiltration device enters the return water tank 12, and the concentrated water can be returned to the collection tank 1. The recycled water tank 12 is connected to the water supply system 24 of the reaction tank 3 via a pipeline. The recycled water tank 12 is connected to the silicon carbide membrane device 5 and the nanofiltration device 11 via the outlet pipe of the backwash pump 13, which can backwash the membrane filtration system.

[0016] This device features integrated equipment, high system safety and reliability, and can recycle valuable heavy metals. It reduces the amount of sludge produced by ordinary sedimentation methods, can deeply treat and reuse wastewater, achieve zero discharge, effectively reduce the pollution of heavy metal wastewater to the environment, truly turn waste into treasure, and greatly reduce the cost of production wastewater treatment.

Claims

1. A device for heavy metal wastewater treatment and reuse, characterized in that: It mainly consists of a collection tank, a booster pump, a reaction tank, a circulation pump, a silicon carbide membrane device, a product water tank, a raw water pump, a bag filter, a security filter, a high-pressure pump, a nanofiltration device, a recycled water tank, and a backwash pump, all connected sequentially by pipelines. It also includes a chromic acid recycling tank and a dewatering machine. The silicon carbide membrane device has an inlet pipe, a product water pipe, a product discharge pipe, a recycling pipe, a concentrate pipe, and a concentrate discharge pipe. The product water pipe and the recycling pipe are connected in parallel and both are equipped with electric valves. The concentrate pipe is connected to the reaction tank. The silicon carbide membrane device is connected to the product water tank via the product water pipe and to the chromic acid recycling tank via the recycling pipe. The reaction tank is connected to the inlet pipe of the silicon carbide membrane device via the circulation pump, which is equipped with an inlet electric valve. The circulation pump is connected to the dewatering machine via a pipeline, which is also equipped with an electric valve.

2. The heavy metal wastewater treatment and reuse device according to claim 1, characterized in that: The reaction tank is equipped with an alkali addition system, a water addition system, a hydrogen peroxide addition system, and a stirring system, as well as a pH meter, an OPR online meter, and a level gauge.

3. The apparatus for heavy metal wastewater treatment and reuse according to claim 1, wherein: The water production tank is equipped with a metal scavenging agent dosing system, a stirring system, and a level gauge.

4. The apparatus for heavy metal wastewater treatment and reuse according to claim 1, wherein: The recycled water tank is connected to the water supply system of the reaction tank via a pipeline, and the backwash pump outlet pipe is connected to the silicon carbide membrane device and the nanofiltration device.

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