A device for treating plasticizer process wastewater
By using an acidification reactor and an internal electrolysis method with a carbon-iron catalyst in the treatment of plasticizer wastewater, the problem of excessive alkali usage in existing technologies has been solved, achieving the effects of reducing operating costs and simplifying the process.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- KAIFENG JIUHONG CHEM CO LTD
- Filing Date
- 2025-07-08
- Publication Date
- 2026-07-14
AI Technical Summary
Existing technologies for treating plasticizer wastewater, especially wastewater discharged from phase separators, require large amounts of alkali to adjust the pH value for Fenton process treatment, resulting in high operating costs.
After acidification in an acidification reactor, preliminary oxidation is carried out by internal electrolysis using a carbon-iron catalyst. The generation of ferrous ion flocculents in the carbon-iron catalyst layer and the increase in pH value reduce the amount of alkali used in the subsequent Fenton process, and the process flow is simplified by internal electrolysis.
This reduces the amount of alkali required for the Fenton process to treat plasticizer wastewater, simplifies the process flow, improves work efficiency, and reduces operating costs.
Smart Images
Figure CN224493896U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of equipment for treating plasticizer process wastewater, specifically to a device for treating plasticizer process wastewater. Background Technology
[0002] During the esterification synthesis of plasticizers, a large amount of vapor is discharged from the top of the distillation column, liquefied after heat exchange in the condenser, and then sent to the phase separator. The organic phase is returned to the distillation column as reflux liquid and exchanges heat with the rising gas flow within the column. The inorganic phase is sent to the wastewater treatment unit for treatment via a wastewater pipeline. Because this wastewater discharged from the phase separator contains a large amount of emulsified lipids, its treatment is relatively complex. Furthermore, the COD of this wastewater discharged from the phase separator is higher than that of wastewater from other plasticizer production processes. Therefore, this wastewater requires separate pretreatment to reduce its COD to a preset range before it can be mixed with wastewater from other processes for subsequent treatment.
[0003] Plasticizers are classified by chemical structure into aliphatic diesters, phthalates (including phthalates and terephthalates), polyphenol esters, benzoates, polyol esters, chlorinated hydrocarbons, epoxy compounds, citrates, polyesters, and many others. There are over a hundred types of plasticizers, but the most commonly used are a group of compounds called phthalates (or phthalates salts, also known as phthalates). Taking common phthalates as an example, the wastewater discharged from phase separators contains a large amount of phthalic acid esters. Current technology utilizes the addition of sulfuric acid to this wastewater to decompose the phthalic acid esters into phthalic acid and alcohols. The phthalic acid is recovered as a solid precipitate, while the alcohol dissolves in the water. Then, chemical treatment methods are used to reduce the COD in the wastewater. The Fenton process is a commonly used chemical method. Before using the Fenton process to treat wastewater, the pH value of the solution needs to be adjusted. Adjusting plasticizer wastewater that has already undergone acid demulsification undoubtedly requires a significant amount of alkali. Therefore, there is room for improvement in the existing technology, aiming to reduce the amount of alkali needed for treating plasticizer wastewater using the Fenton process after acid demulsification, thereby reducing enterprise operating costs. Summary of the Invention
[0004] To address the shortcomings of existing technologies, this utility model provides a treatment device for plasticizer process wastewater that reduces the amount of alkali required for treatment using the Fenton process after demulsification with acid, thereby overcoming the deficiencies in existing technologies.
[0005] The technical solution adopted by this utility model is as follows: a treatment device for plasticizer process wastewater, including an acidification reactor, a first centrifuge installed at the outlet end of the acidification reactor, an inlet end of a centrifugal liquid conveying pipe installed at the liquid phase outlet end of the first centrifuge, a first shut-off valve installed on the centrifugal liquid conveying pipe, a stirring tank installed at the outlet end of the centrifugal liquid conveying pipe, a flow equalization ring installed on the outside of the stirring tank, and a plurality of first conveying branch pipes installed between the flow equalization ring and the stirring tank, each first conveying branch pipe having a valve installed at its end near the stirring tank. The microporous filter plate has an inlet end of a main delivery pipe on the flow equalization ring. The main delivery pipe has an inlet end of a booster pump and an inlet end of a catalytic converter arranged sequentially along the direction from near to far from the flow equalization ring. A guide cone is installed inside the catalytic converter on one side of the inlet end. A baffle is installed inside the catalytic converter on the side of the guide cone away from the inlet end. A cylindrical carbon-iron catalyst layer is arranged between the baffle and the guide cone. A through hole is opened on the baffle on one side of the carbon-iron catalyst layer. The centrifugal liquid delivery pipe between the first shut-off valve and the stirring tank is connected to the outlet end of the catalytic converter.
[0006] Preferably, each of the first delivery branch pipes is provided with a second shut-off valve. The main delivery pipe between the booster pump and the flow equalization ring is provided with the outlet end of the first return pipe, a third shut-off valve and a water delivery pipe in sequence along the direction from the flow equalization ring to the booster pump. The main delivery pipe between the booster pump and the catalytic tank is provided with a fourth shut-off valve. The water delivery pipe is provided with a fifth shut-off valve. The first return pipe is provided with a sixth shut-off valve. The sixth shut-off valve is connected to the inlet end of the main delivery pipe between the booster pump and the first return pipe.
[0007] Preferably, the centrifugal liquid delivery pipe and the catalytic tank are connected by a second reflux pipe. The second reflux pipe is provided with the outlet end of a second delivery branch pipe, a seventh shut-off valve, and the outlet end of a third reflux pipe in sequence along the direction from the catalytic tank to the centrifugal liquid delivery pipe. An eighth shut-off valve is provided on both the second delivery branch pipe and the third reflux pipe. The sixth shut-off valve is connected to the inlet end of the first reflux pipe and the second delivery branch pipe between the main delivery pipe and the main delivery pipe. The fourth shut-off valve is connected to the inlet end of the main delivery pipe and the third reflux pipe between the catalytic tank.
[0008] Preferably, both the mixing tank and the acidification reactor are equipped with pH sensors, the bottom of the mixing tank is provided with the inlet end of the mixed liquid delivery pipe, the mixed liquid delivery pipe is provided with a ninth shut-off valve, and the outlet end of the mixed liquid delivery pipe is provided with the inlet end of the second centrifuge.
[0009] Preferably, both the stirring tank and the acidification reactor are equipped with liquid level sensors.
[0010] Preferably, the mixing tank is provided with a mixing shaft, the mixing shaft inside the mixing tank is provided with mixing blades, and a mixing motor is drivenly connected to the mixing shaft.
[0011] The beneficial effects of this invention are as follows: First, this invention transports the plasticizer process wastewater from the phase separator to the acidification reactor to complete acidification, thereby precipitating organic acids and producing acidic wastewater. Then, the acidic wastewater is continuously transported to the carbon-iron catalyst layer. Internal electrolysis is used to perform preliminary oxidation and decomposition on the carbon-iron catalyst layer. During this process, the wastewater discharged from the carbon-iron catalyst layer carries flocculent material containing ferrous ions, which is continuously transported to the carbon-iron catalyst layer along with the acidic wastewater. According to the principle of internal electrolysis, the pH value of the acidic wastewater will continuously increase. In the process of reducing the COD of the acidic wastewater, the pH value of the acidic wastewater is increased, thereby reducing the amount of alkali required for the next step of neutralizing the acidic wastewater. Furthermore, since ferrous ions are introduced during the preliminary oxidation process, there is no need to introduce ferrous ions again in the subsequent deep oxidation process, thus simplifying the process.
[0012] Secondly, both the mixing tank and the acidification reactor described in this invention are equipped with pH sensors, which facilitate the feedback of pH parameters.
[0013] Furthermore, both the mixing tank and the acidification reactor described in this invention are equipped with liquid level sensors; installing liquid level sensors facilitates the feedback of liquid level parameters.
[0014] This utility model has a simple structure, is easy to operate, and has a clever design, which greatly improves work efficiency and has good social and economic benefits. It is a product that is easy to promote and use. Attached Figure Description
[0015] Figure 1 This is a schematic diagram of the structure of this utility model.
[0016] Figure 2 for Figure 1 A magnified view of detail A.
[0017] Figure 3 for Figure 1 A magnified view of detail B. Detailed Implementation
[0018] like Figures 1 to 3As shown, a treatment device for plasticizer process wastewater includes an acidification reactor 1. A first centrifuge 2 is installed at the outlet end of the acidification reactor 1. The inlet end of a centrifuge liquid delivery pipe 3 is installed at the liquid phase outlet end of the first centrifuge 2. A first shut-off valve 4 is installed on the centrifuge liquid delivery pipe 3. A stirring tank 5 is installed at the outlet end of the centrifuge liquid delivery pipe 3. A flow equalization ring 6 is installed on the outside of the stirring tank 5. A plurality of first delivery branch pipes 7 are installed between the flow equalization ring 6 and the stirring tank 5. A microporous filter plate 9 is installed at the end of each first delivery branch pipe 7 near the stirring tank 5. A main delivery pipe is installed on the flow equalization ring 6. At the inlet end of the main conveying pipe 8, a booster pump 10 and the inlet end of the catalytic converter 11 are sequentially arranged along the direction from near the flow equalization ring 6 to far away from the flow equalization ring 6. A guide cone 12 is installed inside the catalytic converter 11 on one side of the inlet end, and a baffle 13 is installed inside the catalytic converter 11 on the side of the guide cone 12 away from the inlet end. A cylindrical carbon-iron catalyst layer 14 is arranged between the baffle 13 and the guide cone 12. A through hole 15 is opened on the baffle 13 on one side of the carbon-iron catalyst layer 14. The centrifugal liquid conveying pipe 3 between the first shut-off valve 4 and the stirring tank 5 is connected to the outlet end of the catalytic converter 11. The diameter of the guide cone 12 near the inlet end of the catalytic converter 11 gradually increases as the guide cone 12 approaches the baffle 13.
[0019] As the filtration time of the liquid in the mixing tank 5 increases with the number of microporous filter plates 9, the flow resistance of each microporous filter plate 9 will become too high due to the adhesion of impurities. Therefore, each of the first delivery branch pipes 7 of this product is respectively equipped with a second shut-off valve 16. The main delivery pipe 8 between the booster pump 10 and the flow equalization ring 6 is sequentially equipped with the outlet end of the first return pipe 17, a third shut-off valve 18 and a water delivery pipe 19 along the direction from the flow equalization ring 6 to the booster pump 10. The main delivery pipe 8 between the booster pump 10 and the catalytic tank 11 is equipped with a fourth shut-off valve 20. The water delivery pipe 19 is equipped with a fifth shut-off valve 21. The first return pipe 17 is equipped with a sixth shut-off valve 22. The sixth shut-off valve 22 is connected to the inlet end of the main delivery pipe 8 between the booster pump 10 and the first return pipe 17. By supplying tap water to the water pipe 19, the tap water is pressurized by the booster pump 10 and then sent back to the equalization ring 6 via the first return pipe 17. Then, the second shut-off valve 16 is opened in sequence, and several first delivery branch pipes 7 supply tap water to the mixing tank 5 in sequence, thereby achieving backflushing of several microporous filter plates 9 in sequence, thereby reducing the impurities attached to the upper surface of the microporous filter plates 9.
[0020] Furthermore, the outer surface of the carbon-iron catalyst layer 14 will also be covered with precipitates formed by ferrous ions, thereby increasing the flow resistance of the carbon-iron catalyst layer 14. Therefore, the centrifugal liquid delivery pipe 3 and the catalyst tank 11 are connected by the second return pipe 23. The second return pipe 23 is provided with the outlet end of the second delivery branch pipe 24, the seventh shut-off valve 25 and the outlet end of the third return pipe 26 in sequence along the direction from the catalyst tank 11 to the centrifugal liquid delivery pipe 3. The second delivery branch pipe 24 and the third return pipe 26 are each provided with an eighth shut-off valve 27. The sixth shut-off valve 22 is connected to the inlet end of the first return pipe 17 and the second delivery branch pipe 24 between the delivery main pipe 8 and the sixth shut-off valve 22. The fourth shut-off valve 20 is connected to the inlet end of the delivery main pipe 8 and the third return pipe 26 between the catalyst tank 11. Tap water is supplied through water pipe 19. After being pressurized by booster pump 10, the pressurized tap water is sequentially delivered to the outlet of catalytic tank 11 via first return pipe 17 and second delivery branch pipe 24. The pressurized tap water then enters the inner cavity of carbon-iron catalyst layer 14 through through hole 15, thereby backflushing impurities adhering to the outer surface of carbon-iron catalyst layer 14. The backflushed tap water is then sequentially delivered to the stirring tank 5 via the inlet of catalytic tank 11, third return pipe 26, second return pipe 23, and centrifugal liquid delivery pipe 3. This process backflushing impurities adhering to the outer surface of carbon-iron catalyst layer 14 reduces the flow resistance of carbon-iron catalyst layer 14.
[0021] Both the stirring tank 5 and the acidification reactor 1 are equipped with pH sensors 28, which facilitates the feedback of pH parameters. The bottom of the stirring tank 5 is provided with the inlet end of the mixed liquid conveying pipe 29, the mixed liquid conveying pipe 29 is provided with a ninth shut-off valve 30, and the outlet end of the mixed liquid conveying pipe 29 is provided with the inlet end of the second centrifuge 31.
[0022] Both the stirring tank 5 and the acidification reactor 1 are equipped with liquid level sensors 32; the installation of liquid level sensors 32 facilitates the feedback of liquid level parameters.
[0023] The mixing tank 5 is equipped with a stirring shaft 33, and stirring blades 34 are provided on the stirring shaft 33 inside the mixing tank 5. A stirring motor 35 is driven and connected to the stirring shaft 33; thereby facilitating the stirring of the medium in the mixing tank 5.
[0024] The usage instructions for this product are as follows: Figures 1 to 3 As shown, it includes the following steps:
[0025] S1. Process wastewater from the phase separator is transported to the acidification reactor 1 to a preset liquid level. Then, sulfuric acid is added to the acidification reactor 1. When the parameter fed back by the pH sensor 28 on the acidification reactor 1 reaches a preset range, the addition of sulfuric acid to the acidification reactor 1 is stopped. Then, the process wastewater in the acidification reactor 1 is intermittently stirred. At this time, the process wastewater in the acidification reactor 1 has completed acidification. The process wastewater in the acidification reactor 1 continues to precipitate organic acid. After acidification is completed and the intermittent stirring is completed for a preset time, the process wastewater in the acidification reactor 1 no longer precipitates organic acid. The process wastewater in the acidification reactor 1 is then thoroughly stirred to form a suspension, and this suspension is transported to the first centrifuge 2 for solid-liquid separation. The organic acid precipitate is discharged through the solid phase outlet of the first centrifuge 2. The workers can recover the organic acid for further processing and use it as raw material. The remaining liquid phase is transported to the mixing tank 5 through the centrifugal liquid conveying pipe 3.
[0026] S2. Open several second shut-off valves 16 and booster pump 10. The centrifugal liquid in the stirring tank 5 enters the flow equalization ring 6 through several first delivery branch pipes 7, and then enters the delivery main pipe 8. After being pressurized by the booster pump 10, it enters the inner cavity of the catalytic tank 11 through the inlet end of the catalytic tank 11. After being guided by the guide cone 12, it enters the inner cavity between the carbon-iron catalyst layer 14 and the catalytic tank 11. Then, it is catalyzed by the carbon-iron catalyst layer 14. The catalyzed liquid contains flocculent matter containing ferrous ions to form a mixed liquid flow. Then, the mixed liquid flow is sent back to the stirring tank 5 through the through hole 15, the outlet end of the catalytic tank 11, the second return pipe 23 and the centrifugal liquid delivery pipe 3. The medium in the stirring tank 5 is filtered by the microporous filter plate 9 and then enters the flow equalization ring 6 again through several first delivery branch pipes 7 to form a circulation. During this period, the flocculent matter containing ferrous ions is retained in the stirring tank 5 by several microporous filter plates 9.
[0027] S3. When the pH sensor 28 installed on the mixing tank 5 reaches the first preset range, the booster pump 10 and several second shut-off valves 16 are turned off. Then, sodium hydroxide is continuously added to the mixing tank 5 and the stirring motor 35 is turned on to drive the stirring shaft 33 and stirring blades 34 to rotate, thereby stirring the medium in the mixing tank 5. When the pH sensor 28 installed on the mixing tank 5 reaches the second preset range, the addition of sodium hydroxide to the mixing tank 5 is stopped. Then, a preset amount of hydrogen peroxide is added to the mixing tank 5 and the stirring motor 35 is turned on to drive the stirring shaft 33 and stirring blades 34 to rotate, thereby stirring the medium in the mixing tank 5, causing ferrous ions to form flocculent precipitates and be oxidized to ferric ions to form flocculent precipitates, thereby completing the Fenton reaction. After the stirring shaft 33 and stirring blades 34 have stirred the medium in the stirring tank 5 for a preset time, the stirring motor 35 is turned off, and finally the ninth shut-off valve 30 is opened to transport the medium in the stirring tank 5 to the second centrifuge 31 for solid-liquid separation. The liquid phase is sent to the next process for further processing, while the solid phase is iron sludge that is collected and centrally processed.
[0028] In this embodiment, the plasticizer process wastewater transported by the phase separator is fed into the acidification reactor 1 to complete acidification, thereby precipitating organic acids and producing acidic wastewater. This acidic wastewater is then continuously fed to the carbon-iron catalyst layer 14, where it undergoes preliminary oxidation and decomposition using internal electrolysis. During this process, the wastewater discharged from the carbon-iron catalyst layer 14 carries flocculent material containing ferrous ions, which continues to be transported to the catalyst layer 14 along with the acidic wastewater. According to the principle of internal electrolysis, the pH value of the acidic wastewater will continuously increase. The process of reducing the COD of the acidic wastewater increases its pH value, thereby reducing the amount of alkali required for the next step of neutralizing the acidic wastewater. Furthermore, since ferrous ions are introduced during the preliminary oxidation process, they do not need to be introduced again during the subsequent deep oxidation process, simplifying the process.
[0029] The embodiments described above are merely preferred embodiments of this utility model and are not intended to limit the scope of implementation of this utility model. Therefore, all equivalent changes or modifications made to the structure, features and principles described in the patent claims of this utility model should be included within the scope of the patent application of this utility model.
Claims
1. A device for treating plasticizer process wastewater, characterized in that: The system includes an acidification reactor (1), a first centrifuge (2) is installed at the outlet end of the acidification reactor (1), the inlet end of a centrifugal liquid delivery pipe (3) is installed at the liquid phase outlet end of the first centrifuge (2), a first shut-off valve (4) is installed on the centrifugal liquid delivery pipe (3), a stirring tank (5) is installed at the outlet end of the centrifugal liquid delivery pipe (3), a flow equalization ring (6) is installed on the outside of the stirring tank (5), and several first delivery branch pipes (7) are installed between the flow equalization ring (6) and the stirring tank (5). Each first delivery branch pipe (7) is provided with a microporous filter plate (9) at one end near the stirring tank (5). The inlet end of a main delivery pipe (8) is installed on the flow equalization ring (6). A booster pump (10) and the inlet end of a catalyst tank (11) are arranged sequentially along the direction from near the flow equalization ring (6) to away from the flow equalization ring (6). A guide cone (12) is arranged in the catalyst tank (11) on one side of the inlet end of the catalyst tank (11). A baffle (13) is arranged in the catalyst tank (11) on the side of the guide cone (12) away from the inlet end of the catalyst tank (11). A carbon-iron catalyst layer (14) in the shape of a circular tube is arranged between the baffle (13) and the guide cone (12). A through hole (15) is opened on the baffle (13) on one side of the carbon-iron catalyst layer (14). The centrifugal liquid delivery pipe (3) between the first shut-off valve (4) and the stirring tank (5) is connected to the outlet end of the catalyst tank (11).
2. The device for treating plasticizer process wastewater according to claim 1, characterized in that: Each of the first delivery branch pipes (7) is provided with a second shut-off valve (16). The main delivery pipe (8) between the booster pump (10) and the flow equalization ring (6) is provided with the outlet end of the first return pipe (17), the third shut-off valve (18) and the water delivery pipe (19) in sequence along the direction from the flow equalization ring (6) to the booster pump (10). The main delivery pipe (8) between the booster pump (10) and the catalyst tank (11) is provided with a fourth shut-off valve (20). The water delivery pipe (19) is provided with a fifth shut-off valve (21). The first return pipe (17) is provided with a sixth shut-off valve (22). The sixth shut-off valve (22) is connected to the inlet end of the main delivery pipe (8) between the booster pump (10) and the first return pipe (17).
3. The device for treating plasticizer process wastewater according to claim 1, characterized in that: The centrifugal liquid delivery pipe (3) and the catalyst tank (11) are connected by a second return pipe (23). The second return pipe (23) is provided with the outlet end of the second delivery branch pipe (24), the seventh shut-off valve (25) and the outlet end of the third return pipe (26) in sequence along the direction from the catalyst tank (11) to the centrifugal liquid delivery pipe (3). The second delivery branch pipe (24) and the third return pipe (26) are each provided with an eighth shut-off valve (27). The sixth shut-off valve (22) is connected to the first return pipe (17) between the delivery main pipe (8) and the inlet end of the second delivery branch pipe (24). The fourth shut-off valve (20) is connected to the inlet end of the delivery main pipe (8) between the catalyst tank (11) and the third return pipe (26).
4. The device for treating plasticizer process wastewater according to claim 1, characterized in that: Both the stirring tank (5) and the acidification reactor (1) are equipped with a pH sensor (28). The bottom of the stirring tank (5) is provided with the inlet end of the mixed liquid conveying pipe (29). The mixed liquid conveying pipe (29) is provided with a ninth shut-off valve (30). The outlet end of the mixed liquid conveying pipe (29) is provided with the inlet end of the second centrifuge (31).
5. The device for treating plasticizer process wastewater according to claim 1, characterized in that: The stirring tank (5) and the acidification reactor (1) are each equipped with a liquid level sensor (32).
6. The apparatus for treating plasticizer process wastewater according to claim 1, characterized in that: The mixing tank (5) is provided with a stirring shaft (33), and the stirring shaft (33) inside the mixing tank (5) is provided with stirring blades (34). A stirring motor (35) is connected to the stirring shaft (33).