An organic solvent recovery treatment system
By recovering DMF solvent through a multi-stage reverse osmosis treatment system, the problems of high cost, complex process and large footprint in DMF wastewater treatment have been solved. It has achieved efficient solvent recovery and water reuse, simplified the process flow and reduced the reagent consumption of the production line and the pressure on wastewater treatment.
Patent Information
- Application Number
- CN202522116736.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-30
- Publication Date
- 2026-08-25
- Estimated Expiration
- 2035-09-30
AI Technical Summary
Existing DMF wastewater treatment methods suffer from high treatment costs, complex processes or large land areas, and high maintenance difficulties. In particular, the recovery efficiency of DMF organic solvents during reverse osmosis membrane production is low, and direct discharge will increase the treatment load of wastewater treatment plants.
An organic solvent recovery and treatment system is adopted, including an inlet tank, a first filter device, a first reverse osmosis device, a reuse concentrate tank, a second filter device, and a secondary reverse osmosis device. Through multi-stage reverse osmosis treatment, DMF is concentrated to 10-25% and reused in the production line, and the freshwater meets the production line reuse standards.
It achieves efficient recovery of organic solvents and reuse of water, simplifies the process, reduces operating costs and floor space, reduces wastewater treatment pressure, and reduces the consumption of reagents and pure water in the production line.
Smart Images
Figure CN224677867U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of wastewater treatment technology, and more specifically, to an organic solvent recovery and treatment system. Background Technology
[0002] DMF is a common solvent in reverse osmosis membrane materials, therefore, the production process of reverse osmosis membranes often results in the generation of DMF-containing wastewater. Since DMF wastewater can cause significant harm to the environment and human life, it must be effectively treated before being discharged into the environment. Currently, the main methods for treating DMF wastewater include physicochemical methods (distillation, extraction, and physical adsorption), chemical methods (photocatalytic oxidation and supercritical water oxidation), and biochemical methods. Distillation is used to recover wastewater containing more than 30 wt% DMF, while extraction is used to treat wastewater containing 10 wt%-30 wt%. When multi-stage extraction is combined with distillation, the DMF recovery rate can reach 99%. Physical adsorption can achieve compliant discharge of wastewater containing 0.05 wt%-10 wt% DMF, but it carries the risk of secondary pollution. Supercritical water oxidation can treat wastewater with DMF content of 90 wt%. Its principle is to utilize the properties of supercritical water, allowing organic pollutants in the wastewater to fully dissolve and react with oxygen, oxidizing them into non-toxic and harmless CO2, H2O, and other simple small molecule compounds, thus achieving wastewater purification. However, this method requires stringent operating conditions, including high temperature and high pressure, and is costly. Biological methods primarily utilize microbial metabolism to degrade organic matter in wastewater, including aerobic and anaerobic treatment methods. Biological methods for treating organic matter in wastewater are mature and cost-effective. However, for wastewater containing DMF, the toxicity to microorganisms is relatively high, the microbial acclimatization and cultivation period is long, and the microorganisms are prone to mutation, making DMF degradation more difficult. Therefore, biological methods are generally used to treat wastewater with DMF content less than 3 wt%.
[0003] Currently, wastewater from reverse osmosis membrane production is centrally treated at the plant's wastewater treatment plant via a biochemical system before being discharged into the municipal sewer network. The wastewater from the coagulation bath tank in the production line mainly contains 7%-9% DMF organic solvent. Directly discharging this into the plant's wastewater treatment plant would: firstly, increase the treatment load on the plant; and secondly, the pollutants in this wastewater are relatively simple, mainly containing DMF organic solvent, so direct discharge into the wastewater treatment plant would, to some extent, waste the DMF reagent.
[0004] Currently, the main methods for treating DMF wastewater suffer from high treatment costs, complex processes, large land areas, and high maintenance difficulties. Utility Model Content
[0005] To address the problem of how to recover organic solvents from wastewater, this invention provides an organic solvent recovery and treatment system, comprising:
[0006] The system includes an inlet tank, a first filter, a second filter, a first-stage reverse osmosis unit, a second-stage reverse osmosis unit, a concentrate recycling tank, and a dilute recycling tank.
[0007] The outlet of the inlet tank is connected to the inlet of the first filter device, the outlet of the first filter device is connected to the inlet of the first-stage reverse osmosis device, the concentrate outlet of the first-stage reverse osmosis device is connected to the inlet of the reuse concentrate tank, the dilute outlet of the first-stage reverse osmosis device is connected to the inlet of the second filter device, the outlet of the second filter device is connected to the inlet of the second-stage reverse osmosis device, the concentrate outlet of the second-stage reverse osmosis device is connected to the inlet of the inlet tank, and the dilute outlet of the second-stage reverse osmosis device is connected to the reuse dilute tank.
[0008] In some embodiments, the concentration of the organic solution in the inlet tank is lower than the concentration of the organic solution in the reuse concentrate tank.
[0009] In some embodiments, the concentration ratio of the organic solution in the inlet tank to the organic solution in the reuse concentrate tank is 7-9:10-25.
[0010] In some embodiments, the system further includes a collection tank, wherein the freshwater outlet of the first-stage reverse osmosis device is connected to the inlet of the collection tank, and the outlet of the collection tank is connected to the inlet of the second filtration device.
[0011] In some embodiments, the device further includes a first booster pump, the inlet of which is connected to the outlet of the inlet tank, and the outlet of which is connected to the inlet of the first filter device.
[0012] In some embodiments, a second booster pump is further included, the inlet of which is connected to the outlet of the collection tank, and the outlet of which is connected to the inlet of the second filter device.
[0013] In some embodiments, the outlet of the inlet tank is connected to the inlet of the first booster pump via a first pipe; the outlet of the first booster pump is connected to the first filter via a second pipe; the outlet of the first filter is connected to the inlet of the first-stage reverse osmosis unit via a third pipe; the concentrate outlet of the first-stage reverse osmosis unit is connected to the reuse concentrate tank via a fourth pipe; the dilute outlet of the first-stage reverse osmosis unit is connected to the inlet of the collection tank via a fifth pipe; the outlet of the collection tank is connected to the second booster pump via a sixth pipe; the second booster pump is connected to the inlet of the second filter via a seventh pipe; the outlet of the second filter is connected to the inlet of the second-stage reverse osmosis unit via an eighth pipe; the concentrate outlet of the second-stage reverse osmosis unit is connected to the inlet of the inlet tank via a ninth pipe; and the dilute outlet of the second-stage reverse osmosis unit is connected to the reuse dilute tank via a tenth pipe.
[0014] In some embodiments, the filter elements of the first filter device and the second filter device are less than or equal to 5 μm.
[0015] In some embodiments, the molecular weight cutoff of the first-stage reverse osmosis unit and the molecular weight cutoff of the second-stage reverse osmosis unit are 100–200 Daltons.
[0016] In some embodiments, the molecular weight cutoff of the secondary reverse osmosis unit is less than that of the primary reverse osmosis unit.
[0017] In some embodiments, the organic solvent includes DMF.
[0018] To address the problem of how to recover organic solvents from wastewater, this invention has the following advantages:
[0019] This novel organic solvent recovery and treatment system not only recovers organic solvents but also water, simplifying the recovery process, reducing operating costs compared to other processes, and facilitating implementation. The system's simple structure results in a small footprint. Concentrated organic solvents can be recycled back to the production line, reducing reagent consumption. The treated water meets the production line's reuse standards, reducing pure water usage by approximately half and alleviating pressure on pure water preparation and supply. Furthermore, this system reduces the wastewater treatment load, thereby lowering wastewater treatment pressure and decreasing wastewater discharge. Attached Figure Description
[0020] Figure 1 An embodiment of an organic solvent recovery and treatment system is shown.
[0021] Reference numerals in the attached diagram: 1-Inlet tank; 2-First filtration device; 3-First-stage reverse osmosis device; 4-Concentrate tank; 5-Collection tank; 6-Second filtration device; 7-Second-stage reverse osmosis device; 8-Dilute tank; 9-First booster pump; 10-Second booster pump; 11-First pipeline; 12-Second pipeline; 13-Third pipeline; 14-Fourth pipeline; 15-Fifth pipeline; 16-Sixth pipeline; 17-Seventh pipeline; 18-Eighth pipeline; 19-Ninth pipeline; 20-Tenth pipeline. Detailed Implementation
[0022] The present disclosure will now be discussed with reference to several exemplary embodiments. It should be understood that these embodiments are discussed only to enable those skilled in the art to better understand and thus implement the present disclosure, and are not intended to imply any limitation on the scope of the disclosure.
[0023] As used herein, the term "comprising" and its variations are to be interpreted as open-ended terms meaning "including but not limited to". The term "based on" is to be interpreted as "at least partially based on". The terms "one embodiment" and "an embodiment" are to be interpreted as "at least one embodiment". The term "another embodiment" is to be interpreted as "at least one other embodiment". The terms "upper", "lower", "left", "right", "front", "rear", "top", "bottom", "inner", "outer", "vertical", "horizontal", "lateral", "longitudinal", etc., indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. These terms are primarily for the purpose of better describing this application and its embodiments and are not intended to limit the indicated devices, elements, or components to having a specific orientation or being constructed and operated in a specific orientation. Furthermore, some of the above terms may be used to indicate other meanings besides orientations or positional relationships; for example, the term "upper" may in some cases indicate a dependency or connection relationship. Those skilled in the art can understand the specific meaning of these terms in this application according to the specific circumstances. In addition, the terms "installed", "set up", "equipped with", "connected", and "linked" should be interpreted broadly. For example, it can be a fixed connection, a detachable connection, or an integral structure; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or an internal connection between two devices, elements, or components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances. Furthermore, the terms "first," "second," etc., are mainly used to distinguish different devices, elements, or components (the specific types and structures may be the same or different), and are not used to indicate or imply the relative importance or quantity of the indicated devices, elements, or components. Unless otherwise stated, "a plurality of" means two or more.
[0024] This embodiment discloses an organic solvent recovery and treatment system, such as Figure 1 As shown, it includes:
[0025] Inlet tank 1, first filter device 2, second filter device 6, first-stage reverse osmosis device 3, second-stage reverse osmosis device 7, concentrate recycling tank 4 and dilute recycling tank 8;
[0026] The outlet of the inlet tank 1 is connected to the inlet of the first filter device 2, the outlet of the first filter device 2 is connected to the inlet of the first-stage reverse osmosis device 3, the concentrate outlet of the first-stage reverse osmosis device 3 is connected to the inlet of the reuse concentrate tank 4, the dilute outlet of the first-stage reverse osmosis device 3 is connected to the inlet of the second filter device 6, the outlet of the second filter device 6 is connected to the inlet of the second-stage reverse osmosis device 7, the concentrate outlet of the second-stage reverse osmosis device 7 is connected to the inlet of the inlet tank 1, and the dilute outlet of the second-stage reverse osmosis device 7 is connected to the reuse dilute tank 8.
[0027] In this embodiment, when the organic solvent recovery and treatment system treats the wastewater from reverse osmosis membrane production, the concentration of DMF (N,N-dimethylformamide) organic solvent in the wastewater is 7-9%. The wastewater first enters the feed tank 1. After homogenization and equalization in the feed tank 1, the wastewater enters the first filter device 2. The first filter device 2 removes larger particulate impurities from the water. The permeate from the first filter device 2 passes through its outlet to the first-stage reverse osmosis device 3. The DMF organic solvent in the wastewater is concentrated by the first-stage reverse osmosis device 3 and then enters the reuse concentrate tank 4 from the concentrate outlet of the first-stage reverse osmosis device 3 along with the first-stage reverse osmosis concentrate. The concentration of DMF organic solvent concentrated by the first-stage reverse osmosis device 3 reaches 10-25%. The DMF organic solvent in tank 4 is returned to the workshop production line for reuse. The concentration of DMF organic solvent in the permeate water of the first-stage reverse osmosis unit 3 is 1-2%, which is lower than the requirements of the workshop production line. The permeate water of the first-stage reverse osmosis unit 3 enters the second filtration unit 6 through the desalination outlet. The second filtration unit 6 removes larger impurities from the wastewater. The permeate water of the second filtration unit 6 enters the second-stage reverse osmosis unit 7 through its outlet. The permeate water of the second-stage reverse osmosis unit 7 meets the requirements for reuse in the production line and can be returned to the workshop production line for reuse. The permeate water of the second-stage reverse osmosis unit 7 enters the reuse desalination tank 8 through its desalination outlet. The water in the reuse desalination tank 8 is sent to the workshop for use as pure water makeup. The concentrate of the second-stage reverse osmosis unit 7 enters the inlet tank 1 through the concentrate outlet for further recycling.
[0028] The antifouling reverse osmosis membrane concentrates the DMF (7%-9%) organic solvent in the production wastewater and then recycles it in the production workshop. The concentration of the concentrated DMF organic solvent can reach 10%-25%.
[0029] The organic solvent recovery and treatment system in this embodiment not only recovers organic solvents but also water, simplifying the recovery process, reducing operating costs compared to other processes, and facilitating implementation. The system's simple structure results in a small footprint. The concentrated DMF organic solvent can be recycled back to the production line, reducing reagent consumption. The treated water meets the production line's reuse water standards, reducing pure water usage by approximately half and alleviating pressure on pure water preparation and supply. Furthermore, this system reduces the wastewater treatment load, thereby lowering wastewater treatment pressure and decreasing wastewater discharge.
[0030] Preferably, both the first filter device 2 and the second filter device 6 are security filters.
[0031] In some embodiments, the concentration of the organic solution in the inlet tank 1 is lower than the concentration of the organic solution in the reuse concentrate tank 4.
[0032] In this embodiment, the reuse concentrate tank 4 is provided for temporary storage of the organic solvent concentrate concentrated by the first-stage reverse osmosis unit 3.
[0033] In some embodiments, the concentration ratio of the organic solution in the inlet tank 1 to the organic solution in the reuse concentrate tank 4 is 7-9:10-25.
[0034] In this embodiment, the recovery of organic solvents is demonstrated.
[0035] In some embodiments, the system further includes a collection tank 5, wherein the freshwater outlet of the first-stage reverse osmosis device 3 is connected to the inlet of the collection tank 5, and the outlet of the collection tank 5 is connected to the inlet of the second filtration device 6.
[0036] In this embodiment, a collection tank 5 is provided for temporarily storing the freshwater produced by the first-stage reverse osmosis unit 3.
[0037] In some embodiments, the system further includes a first booster pump 9, the inlet of which is connected to the outlet of the inlet tank 1, and the outlet of which is connected to the inlet of the first filter device 2.
[0038] In this embodiment, the first booster pump 9 is provided to ensure that the liquid in the inlet tank 1 can flow into the first filter device 2.
[0039] In some embodiments, a second booster pump 10 is also included, the inlet of which is connected to the outlet of the collection tank 5, and the outlet of which is connected to the inlet of the second filter device 6.
[0040] In this embodiment, the second booster pump 10 is provided to ensure that the liquid in the collection tank 5 can flow into the second filter device 6.
[0041] In some embodiments, the outlet of the inlet tank 1 is connected to the inlet of the first booster pump 9 via a first pipe 11; the outlet of the first booster pump 9 is connected to the first filter device 2 via a second pipe 12; the outlet of the first filter device 2 is connected to the inlet of the first-stage reverse osmosis device 3 via a third pipe 13; the concentrate outlet of the first-stage reverse osmosis device 3 is connected to the reuse concentrate tank 4 via a fourth pipe 14; and the dilute outlet of the first-stage reverse osmosis device 3 is connected to the collection tank 5 via a fifth pipe 15. The inlet of the liquid collection tank 5 is connected to the outlet of the second lift pump 10 via the sixth pipe 16. The second lift pump 10 is connected to the inlet of the second filter device 6 via the seventh pipe 17. The outlet of the second filter device 6 is connected to the inlet of the secondary reverse osmosis device 7 via the eighth pipe 18. The concentrate outlet of the secondary reverse osmosis device 7 is connected to the inlet of the inlet tank 1 via the ninth pipe 19. The dilute outlet of the secondary reverse osmosis device 7 is connected to the reuse dilute tank 8 via the tenth pipe 20.
[0042] In this embodiment, the reliability of the connections between the various structures of the organic solvent recovery and treatment system is ensured by the arrangement of pipelines.
[0043] In some embodiments, the filter elements of the first filter device 2 and the second filter device 6 are less than or equal to 5 μm.
[0044] In this embodiment, by setting the filter elements of the first filter device 2 and the second filter device 6 to be less than or equal to 5μm, it is ensured that the first filter device 2 and the second filter device 6 can remove impurities smaller than 5μm.
[0045] In some embodiments, the molecular weight cutoff of the first-stage reverse osmosis unit 3 and the molecular weight cutoff of the second-stage reverse osmosis unit 7 are 100 to 200 Daltons.
[0046] In this embodiment, by setting the molecular weight cutoff of the first-stage reverse osmosis unit 3 and the molecular weight cutoff of the second-stage reverse osmosis unit 7 to be 100-200 Daltons, not only is the concentration of the organic solvent concentrate produced by the first-stage reverse osmosis unit 3 guaranteed, but also the quality of the freshwater produced by the first-stage reverse osmosis unit 3 is guaranteed.
[0047] In some embodiments, the molecular weight cutoff of the secondary reverse osmosis unit 7 is less than that of the primary reverse osmosis unit 3.
[0048] Since the first-stage reverse osmosis unit 3 has concentrated and recovered most of the organic solvents in the wastewater, the energy consumption of the second-stage reverse osmosis unit 7 can be reduced by setting the molecular weight cutoff of the second-stage reverse osmosis unit 7 to be smaller than that of the first-stage reverse osmosis unit 3. This makes the organic solvent recovery and treatment system of this embodiment have the characteristic of reducing energy consumption.
[0049] In some embodiments, the organic solvent includes DMF.
[0050] In this embodiment, the organic solvent recovery and treatment system recovers and treats wastewater containing DMF organic solvent.
[0051] The organic solvent recovery and treatment system in this embodiment can also treat organic solvent wastewater with similar polarity to DMF organic solvent, such as dichloromethane.
[0052] Those skilled in the art will understand that the above embodiments are specific examples of implementing this disclosure, and in practical applications, various changes can be made in form and detail without departing from the scope of this disclosure.
Claims
1. An organic solvent recovery and treatment system, characterized in that, include: The system includes an inlet tank, a first filter, a second filter, a first-stage reverse osmosis unit, a second-stage reverse osmosis unit, a concentrate recycling tank, and a dilute recycling tank. The outlet of the inlet tank is connected to the inlet of the first filter device, the outlet of the first filter device is connected to the inlet of the first-stage reverse osmosis device, the concentrate outlet of the first-stage reverse osmosis device is connected to the inlet of the reuse concentrate tank, the dilute outlet of the first-stage reverse osmosis device is connected to the inlet of the second filter device, the outlet of the second filter device is connected to the inlet of the second-stage reverse osmosis device, the concentrate outlet of the second-stage reverse osmosis device is connected to the inlet of the inlet tank, and the dilute outlet of the second-stage reverse osmosis device is connected to the reuse dilute tank.
2. The organic solvent recovery and treatment system according to claim 1, characterized in that, The concentration of the organic solution in the inlet tank is lower than the concentration of the organic solution in the reuse concentrate tank.
3. The organic solvent recovery and treatment system according to claim 2, characterized in that, The concentration ratio of the organic solution in the inlet tank to the organic solution in the reuse concentrate tank is 7-9:10-25.
4. The organic solvent recovery and treatment system according to claim 1, characterized in that, It also includes a collection tank, with the freshwater outlet of the first-stage reverse osmosis device connected to the inlet of the collection tank, and the outlet of the collection tank connected to the inlet of the second filtration device.
5. The organic solvent recovery and treatment system according to claim 4, characterized in that, It also includes a first booster pump, the inlet of which is connected to the outlet of the inlet tank, and the outlet of which is connected to the inlet of the first filter device.
6. The organic solvent recovery and treatment system according to claim 5, characterized in that, It also includes a second lift pump, the inlet of which is connected to the outlet of the collection tank, and the outlet of which is connected to the inlet of the second filter device.
7. The organic solvent recovery and treatment system according to claim 6, characterized in that, The outlet of the inlet tank is connected to the inlet of the first booster pump via a first pipe. The outlet of the first booster pump is connected to the first filter via a second pipe. The outlet of the first filter is connected to the inlet of the first-stage reverse osmosis unit via a third pipe. The concentrate outlet of the first-stage reverse osmosis unit is connected to the reuse concentrate tank via a fourth pipe. The dilute outlet of the first-stage reverse osmosis unit is connected to the inlet of the collection tank via a fifth pipe. The outlet of the collection tank is connected to the second booster pump via a sixth pipe. The second booster pump is connected to the inlet of the second filter via a seventh pipe. The outlet of the second filter is connected to the inlet of the second-stage reverse osmosis unit via an eighth pipe. The concentrate outlet of the second-stage reverse osmosis unit is connected to the inlet of the inlet tank via a ninth pipe. The dilute outlet of the second-stage reverse osmosis unit is connected to the reuse dilute tank via a tenth pipe.
8. The organic solvent recovery and treatment system according to claim 1, characterized in that, The filter elements of the first and second filter devices are less than or equal to 5 μm.
9. An organic solvent recovery and treatment system according to claim 1, characterized in that, The molecular weight cutoff of the first-stage reverse osmosis unit and the molecular weight cutoff of the second-stage reverse osmosis unit are 100 to 200 Daltons.
10. An organic solvent recovery and treatment system according to claim 9, characterized in that, The molecular weight cutoff of the secondary reverse osmosis unit is less than that of the primary reverse osmosis unit.