High-salt sodium hypochlorite wastewater treatment system in polyvinyl chloride production

Abstract

The utility model discloses a high-salt sodium hypochlorite wastewater treatment system in polyvinyl chloride production. Comprising a sodium hypochlorite wastewater tank, a hardness removal lift pump, a pipeline mixer I, a hardness removal device, a pipeline mixer II, a hardness removal buffer tank, an ultrafiltration lift pump, a sand filtration device, an ultrafiltration device security filter, an ultrafiltration device, an ultrafiltration water production tank, a reverse osmosis lift pump, a pipeline mixer III, a reverse osmosis device security filter, a reverse osmosis high-pressure pump and a reverse osmosis device which are connected in sequence, sodium hypochlorite wastewater with the TDS content being smaller than or equal to 20000 mg / L and the COD content being smaller than or equal to 800 mg / L is separated into a low-salt-content reuse water reuse system through a reverse osmosis inter-section pressure pump, a comprehensive adjusting tank, a concentrated water pump, a reuse water tank and a reuse water pump, high-salt-content concentrated water is evaporated and concentrated and then reused for salt dissolving, the problems of resource waste and environmental pollution of the sodium hypochlorite wastewater are fundamentally solved, and the system is suitable for industrial production. And reduction, harmlessness and resource utilization of the sodium hypochlorite wastewater are realized.

Description

Technical Field

[0001] The utility model belongs to the field of wastewater treatment, and particularly relates to a high-salt sodium hypochlorite wastewater treatment system in polyvinyl chloride production. Background Art

[0002] In the calcium carbide method polyvinyl chloride industry, the vast majority of enterprises use sodium hypochlorite solution to remove impurities such as PH3 and H2S contained in crude acetylene gas. In industrial production, sodium hypochlorite with an available chlorine content (mass fraction, the same below) of 0.08% - 0.12% is usually used for washing. When the available chlorine content drops to 0.06%, sodium hypochlorite loses the ability to remove gas impurities, and this part of the ineffective sodium hypochlorite is called sodium hypochlorite wastewater. The purification treatment technology of sodium hypochlorite wastewater mainly includes the precipitation of acetylene gas dissolved in the waste liquid, the reduction of the waste liquid (the reuse and compounding of sodium hypochlorite wastewater cannot fundamentally solve the environmental problems brought by the wastewater), and the resource utilization of the wastewater. After the precipitation of acetylene gas and phosphorus removal treatment, the sodium hypochlorite wastewater still contains a large amount of high-salt impurities such as chlorides, calcium, and magnesium, which makes the impurities in the reaction calcium carbide slag more, resulting in the reduction of the quality of downstream cement. Therefore, the development of the reduction, harmlessness, and resource utilization technology of sodium hypochlorite wastewater is the key idea for current enterprise treatment. According to the wastewater situation, different processes are combined and designed to achieve the lowest wastewater treatment cost and the highest resource utilization efficiency, further alleviating the contradiction between water supply and demand, reducing environmental pollution, and promoting the healthy and stable development of the industry. In view of this, a high-salt sodium hypochlorite wastewater treatment system is designed to fundamentally solve the problems of resource waste and environmental pollution of sodium hypochlorite wastewater. Summary of the Utility Model

[0003] The purpose of the utility model is to solve the problem that the existing technology for purifying and treating sodium hypochlorite wastewater cannot completely achieve zero discharge and reuse of sodium hypochlorite wastewater, and provides a high-salt sodium hypochlorite wastewater treatment system to fundamentally solve the problems of resource waste and environmental pollution of sodium hypochlorite wastewater, and realize the reduction, harmlessness, and resource utilization of sodium hypochlorite wastewater.

[0004] In order to achieve the above object of the utility model, the following technical solutions are adopted:

[0005] A high-salt sodium hypochlorite wastewater treatment system in PVC production, comprising a sodium hypochlorite wastewater tank, a hardness removal lift pump, a pipeline mixer I, a hardness removal device, a pipeline mixer II, a hardness removal buffer tank, an ultrafiltration lift pump, a sand filtration device, a security filter of the ultrafiltration device, an ultrafiltration device, an ultrafiltration product water tank, a reverse osmosis lift pump, a pipeline mixer III, a security filter of the reverse osmosis device, a reverse osmosis high-pressure pump, a reverse osmosis device, an inter-stage pressure boosting pump for reverse osmosis, a comprehensive regulation tank, a concentrated water pump, a reused water tank, and a reused water pump; the discharge port of the sodium hypochlorite wastewater tank is connected to the feed inlet of the hardness removal device through the hardness removal lift pump and the pipeline mixer I, the discharge port of the hardness removal device is connected to the hardness removal buffer tank through the pipeline mixer II, and the discharge port of the hardness removal buffer tank is connected to the feed inlet of the sand filtration device, the security filter of the ultrafiltration device, and the ultrafiltration device in sequence through the ultrafiltration lift pump; the discharge of the ultrafiltration device includes an ultrafiltration product water pipe and an ultrafiltration concentrated water pipe, and the ultrafiltration concentrated water pipe is connected to the hardness removal device; the ultrafiltration device is connected to the ultrafiltration product water tank, the reverse osmosis lift pump, the pipeline mixer III, the security filter of the reverse osmosis device, the reverse osmosis high-pressure pump, and the reverse osmosis device through the ultrafiltration product water pipe; the discharge of the reverse osmosis device includes a reverse osmosis product water pipe and a reverse osmosis concentrated water pipe, the reverse osmosis product water pipe is connected to the reused water tank and the reused water pump, and the reverse osmosis concentrated water pipe is connected to the comprehensive regulation tank and the concentrated water pump.

[0006] Further, the pipeline mixer I is connected to an alkali pipe, a sodium carbonate pipe, a PAC pipe, and a PAM pipe; the pipeline mixer II is connected to a reducing agent pipe I and an acid pipe; the pipeline mixer III is connected to a reducing agent pipe II and a scale inhibitor pipe.

[0007] Further, a sand filtration inlet valve is provided on the feed pipe of the sand filtration device, a sand filtration discharge valve is provided on the discharge pipe, a reflux pipe is provided on the feed pipe and the discharge pipe of the sand filtration device, and a backwashing pipe is further provided on the sand filtration device, and the backwashing pipe is connected to the reused water tank.

[0008] Further, a reprocessing pipe is provided at the discharge of the comprehensive regulation tank, and the reprocessing pipe is connected to the inlet of the hardness removal lift pump.

[0009] Further, the sodium hypochlorite wastewater is wastewater with a TDS ≤ 20000 mg / L and a COD content ≤ 800 mg / L.

[0010] The beneficial effects of the present utility model are as follows: A high-salt sodium hypochlorite wastewater treatment system provided by the present utility model separates sodium hypochlorite wastewater with a TDS content ≤ 20000 mg / L and a COD content ≤ 800 mg / L into a reused water with low salt content for reuse in the system, and the high-salt concentrated water is reused for salt melting after evaporation and concentration, fundamentally solving the problems of resource waste and environmental pollution of sodium hypochlorite wastewater, and realizing the reduction, harmlessness, and resource utilization of sodium hypochlorite wastewater. Description of the Drawings

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

[0012] In the figure: 1. Sodium hypochlorite wastewater tank; 2. Hardness removal lift pump; 3. Pipe mixer I; 4. Alkali pipe; 5. Sodium carbonate pipe; 6. PAC pipe; 7. PAM pipe; 8. Hardness removal device; 9. Pipe mixer II; 10. Reducing agent pipe I; 11. Acid pipe; 12. Hardness removal buffer tank; 13. Ultrafiltration lift pump; 14. Sand filtration device; 14-1. Sand filtration inlet valve; 14-2. Sand filtration outlet valve; 14-3. Sand filtration return pipe; 14-4. Backwashing pipe; 15. Security filter of ultrafiltration device; 16. Ultrafiltration device; 16-1. Ultrafiltration product water pipe; 16-2. Ultrafiltration concentrated water pipe; 17. Ultrafiltration product water tank; 18. Reverse osmosis lift pump; 19. Reducing agent pipe II; 20. Scale inhibitor pipe; 21. Pipe mixer III; 22. Security filter of reverse osmosis device; 23. Reverse osmosis high-pressure pump; 24. Reverse osmosis device; 24-1. Reverse osmosis product water pipe; 24-2. Reverse osmosis concentrated water pipe; 25. Reverse osmosis inter-stage pressure boosting pump; 26. Comprehensive regulation tank; 26-1. Reprocessing pipe; 27. Concentrated water pump; 28. Reclaimed water tank; 29. Reclaimed water pump; 30. pH meter; 31. ORP meter. Specific embodiments

[0013] In order to enable those skilled in the art to more clearly and accurately understand the technical solution of the present utility model, the following will be explained in detail by way of examples. Obviously, the accompanying drawings in the following description are some embodiments of the present utility model. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts. Embodiment

[0014] Refer to Figure 1As shown in the figure, a high-salt secondary sodium wastewater treatment system in PVC production includes a secondary sodium wastewater tank 1, a hardness removal lift pump 2, a pipeline mixer I 3, a hardness removal device 8, a pipeline mixer II 9, a hardness removal buffer tank 12, an ultrafiltration lift pump 13, a sand filtration device 14, a security filter for the ultrafiltration device 15, an ultrafiltration device 16, an ultrafiltration product water tank 17, a reverse osmosis lift pump 18, a pipeline mixer III 21, a security filter for the reverse osmosis device 22, a reverse osmosis high-pressure pump 23, a reverse osmosis device 24, a reverse osmosis inter-stage pressurizing pump 25, a comprehensive regulation tank 26, a concentrated water pump 27, a recycled water tank 28, and a recycled water pump 29. The discharge port of the secondary sodium wastewater tank 1 is connected to the inlet of the hardness removal device 8 through the hardness removal lift pump 2 and the pipeline mixer I 3. The discharge port of the hardness removal device 8 is connected to the hardness removal buffer tank 12 through the pipeline mixer II 9. The discharge port of the hardness removal buffer tank 12 is connected to the inlet of the sand filtration device 14, the security filter for the ultrafiltration device 15, and the ultrafiltration device 16 in sequence through the ultrafiltration lift pump 13. The discharge of the ultrafiltration device 16 includes an ultrafiltration product water pipe 16-1 and an ultrafiltration concentrated water pipe 16-2. The ultrafiltration concentrated water pipe 16-2 is connected to the hardness removal device 8. The ultrafiltration device 16 is connected to the ultrafiltration product water tank 17, the reverse osmosis lift pump 18, the pipeline mixer III 21, the security filter for the reverse osmosis device 22, the reverse osmosis high-pressure pump 23, and the reverse osmosis device 24 through the ultrafiltration product water pipe 16-1. The discharge of the reverse osmosis device 24 includes a reverse osmosis product water pipe 24-1 and a reverse osmosis concentrated water pipe 24-2. The reverse osmosis product water pipe 24-1 is connected to the recycled water tank 28 and the recycled water pump 29. The reverse osmosis concentrated water pipe 24-2 is connected to the comprehensive regulation tank 26 and the concentrated water pump 27.

[0015] Further, the pipeline mixer I 10 is connected to an alkali pipe 4, a sodium carbonate pipe 5, a PAC pipe 6, and a PAM pipe 7. The pipeline mixer II 9 is connected to a reducing agent pipe I 10 and an acid pipe 11. The pipeline mixer III 21 is connected to a reducing agent pipe II 19 and a scale inhibitor pipe 20.

[0016] Further, a sand filtration inlet valve 14-1 is provided on the inlet pipe of the sand filtration device 14, a sand filtration discharge valve 14-2 is provided on the discharge pipe, a reflux pipe 14-3 is provided on the inlet pipe and the discharge pipe of the sand filtration device 14, and a backwash pipe 14-4 is further provided on the sand filtration device 14. The backwash pipe 14-4 is connected to the recycled water tank 28.

[0017] Further, a reprocessing pipe 26-1 is provided at the discharge of the comprehensive regulation tank 26. The reprocessing pipe 26-1 is connected to the inlet of the hardness removal lift pump 2.

[0018] Further, the secondary sodium wastewater is wastewater with a TDS ≤ 20000 mg / L and a COD content ≤ 800 mg / L.

[0019] The operation process of this system: The hypochlorite wastewater with a TDS content of ≤20,000 mg / L and a COD content of ≤800 mg / L is first sent into the hypochlorite wastewater tank 1 for homogenization and equalization, and then conveyed into the hardness removal device 8 by the hardness removal lift pump 2. The pipe mixer Ⅰ set on the pipeline before entering the hardness removal device is connected to the alkali pipe 4, sodium carbonate pipe 5, PAC pipe 6, and PAM pipe 7, and reagents are added to make Ca 2+ and Mg 2+ in the hypochlorite wastewater form precipitates. Then, by adding PAC and PAM, the precipitates are aggregated to form sludge, reducing the hardness of the incoming water and achieving the purpose of hardness removal.

[0020] The effluent from the hardness removal device enters the hardness removal buffer tank 12 through the pipeline filter Ⅱ 9. The reducing agent pipe Ⅰ 10 and acid pipe 11 connected to the pipeline filter Ⅱ 9 add acid and reducing agent, and are monitored in real time by the set pH meter 30 and ORP meter 31; it is sent into the sand filter device 14 for filtration by the ultrafiltration lift pump 13, and then enters the ultrafiltration device 16 through the ultrafiltration device security filter 15. The water molecules, inorganic salts, and small molecule organic substances in the hypochlorite wastewater pass through, while the macromolecular substances such as suspended solids, colloids, proteins, and microorganisms are intercepted, thus achieving the purpose of purification and separation. The ultrafiltration produced water is sent into the ultrafiltration produced water tank 17 through the ultrafiltration produced water pipe 16-1, and the ultrafiltration concentrated water is sent into the hardness removal device 8 for re-treatment through the ultrafiltration concentrated water pipe 16-2.

[0021] The hypochlorite wastewater in the ultrafiltration produced water tank 17 is pressurized by the reverse osmosis lift pump 18, pipeline filter 3, and reverse osmosis device security filter 22 and then sent into the reverse osmosis device 24 for separation again. Reverse osmosis is a separation method that separates the solute and solvent in a solution by means of the selective retention of a semi-permeable membrane under the drive of pressure. The reverse osmosis system mainly removes dissolved salts in water and obtains high-quality product water. The reverse osmosis produced water is sent into the reused water tank 28 through the reverse osmosis produced water pipe 24-1 and then into the reused water system. The reverse osmosis produced water meets the requirements of reused water. The reverse osmosis concentrated water is sent into the comprehensive regulation tank 26 through the reverse osmosis concentrated water pipe 24-2 and then goes to evaporation crystallization for salt reuse. If the concentration of the concentrated water in the comprehensive regulation tank 26 does not meet the standard, it is sent to the inlet of the hardness removal lift pump 2 for re-treatment through the re-treatment pipe 26-1, fundamentally solving the problems of resource waste and environmental pollution of hypochlorite wastewater, and realizing the reduction, harmlessness, and resource utilization of hypochlorite wastewater.

[0022] The above is only the preferred specific implementation manner of the present utility model, but the protection scope of the present utility model is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present utility model, according to the technical solution of the present utility model and its inventive concept, makes equivalent substitutions or changes, and all should be covered within the protection scope of the present utility model.

Claims

1. High-salt and low-sodium wastewater treatment system in polyvinyl chloride production, characterized by: It includes a sodium-substitute wastewater tank, a hardness removal lifting pump, a pipeline mixer I, a hardness removal device, a pipeline mixer II, a hardness removal buffer tank, an ultrafiltration lifting pump, a sand filtration device, an ultrafiltration device security filter, an ultrafiltration device, an ultrafiltration water production tank, a reverse osmosis lifting pump, a pipeline mixer III, a reverse osmosis device security filter, a reverse osmosis high-pressure pump, a reverse osmosis device, a reverse osmosis inter-stage booster pump, a comprehensive regulating tank, a concentrated water pump, a recycled water tank, and a recycled water pump, which are connected in sequence; the discharge port of the sodium-substitute wastewater tank is connected to the feed port of the hardness removal device through the hardness removal lifting pump and the pipeline mixer I, the discharge port of the hardness removal device is connected to the hardness removal buffer tank through the pipeline mixer II, and the hardness removal device is connected to the hardness removal buffer tank through the pipeline mixer II. The discharge port of the hard buffer tank is connected to the sand filter device, the ultrafiltration device safety filter and the ultrafiltration device inlet in sequence through the ultrafiltration lifting pump; the ultrafiltration device discharge includes an ultrafiltration water production pipe and an ultrafiltration concentrated water pipe, and the ultrafiltration concentrated water pipe is connected to the hardness removal device; the ultrafiltration device is connected to the ultrafiltration water production tank, the reverse osmosis lifting pump, the pipeline mixer III, the reverse osmosis device safety filter, the reverse osmosis high-pressure pump and the reverse osmosis device through the ultrafiltration water production pipe; the reverse osmosis device discharge includes a reverse osmosis water production pipe and a reverse osmosis concentrated water pipe, the reverse osmosis water production pipe is connected to the reuse water tank and the reuse water pump, and the reverse osmosis concentrated water pipe is connected to the comprehensive adjustment tank and the concentrated water pump.

2. The high-salt hyposodium wastewater treatment system in polyvinyl chloride production according to claim 1 is characterized in that: The pipeline mixer I is connected to the alkali tube, the sodium carbonate tube, the PAC tube and the PAM tube; the pipeline mixer II is connected to the reducing agent tube I and the acid tube; the pipeline mixer III is connected to the reducing agent tube II and the antiscalant tube.

3. The high-salt hyposodium wastewater treatment system in polyvinyl chloride production according to claim 1 is characterized in that: The sand filter device has a sand filter inlet valve on the inlet pipe, a sand filter outlet valve on the outlet pipe, a reflux pipe on the sand filter inlet pipe and the outlet pipe. The sand filter device is also provided with a backwash pipe, which is connected to a recycled water tank.

4. The high-salt hyposodium wastewater treatment system in polyvinyl chloride production according to claim 1 is characterized in that: The discharge of the comprehensive regulating tank is provided with a reprocessing pipe, and the reprocessing pipe is connected to the inlet of the hardness removal lifting pump.

5. The high-salt hyposodium wastewater treatment system in polyvinyl chloride production according to claim 1 is characterized in that: The sub-sodium wastewater is wastewater with a TDS content of ≤20000 mg / L and a COD content of ≤800 mg / L.

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