Plasticizer wastewater treatment device

Abstract

The utility model relates to a plasticizer wastewater treatment device which comprises a wastewater conveying pipe, a rectifying tower is communicated on the wastewater conveying pipe, a reboiling circulating pipe is arranged on the rectifying tower, a first stop valve, a first booster pump, a reboiler and a first online chromatography are arranged on the reboiling circulating pipe, and a first buffer tank, an acidification reaction kettle and a first centrifugal machine are communicated on the reboiling circulating pipe. The device comprises an acidification reaction kettle, a first centrifugal machine, a first concentration reaction kettle and a second buffer tank, the second buffer tank is communicated with the first concentration reaction kettle through a first concentrated solution conveying pipe, a second concentrated solution conveying pipe is arranged on the first concentrated solution conveying pipe, a third buffer tank is communicated with the second concentrated solution conveying pipe, and the third buffer tank is communicated with the acidification reaction kettle. And the second buffer tank is sequentially communicated with an electrolytic bath, a second concentration reaction kettle, a crystallizing tank and a second centrifugal machine. The wastewater treatment device disclosed by the utility model is convenient to use and has a wide market prospect.

Description

Technical Field

[0001] The utility model relates to the field of plasticizer wastewater treatment, in particular to a plasticizer wastewater treatment device. Background Art

[0002] Plasticizers, also known as plasticizers, are widely used polymer material additives in industrial production. Plasticizers added to polymer materials can improve the performance of polymer materials, reduce production costs, and improve production efficiency. It is an important type of chemical product. As an additive, it is widely used in plastic products, even cosmetics and cleaning agents, especially in polyvinyl chloride plastic products. In order to increase the plasticity and strength of plastics, phthalates need to be added. Currently, commonly used plasticizers include phthalate plasticizers, citric acid plasticizers, paraben plasticizers, and cyclohexane dicarboxylate plasticizers.

[0003] In the production process of the above-mentioned plasticizers, organic anhydrides or organic acids react with alcohols under the catalytic action of sulfuric acid, and sodium hydroxide solution is used for neutralization after the reaction. Therefore, a large amount of wastewater containing salt and organic matter is generated in the production process. After neutralization, most enterprises conduct simple distillation to recover part of the alcohol, and then use triple-effect evaporation or steam mechanical recompression technology (MVR) to reduce and concentrate the wastewater to obtain high-concentration waste liquid or further dry it to obtain solid waste. These waste liquids contain high-concentration organic matter mainly composed of organic anhydrides and high-concentration inorganic matter mainly composed of sodium sulfate. Taking the most common phthalate plasticizer as an example, phthalic anhydride is a low-toxic dangerous substance, which is irritating to the skin and mucous membranes. It is dangerous to cause combustion when it encounters high heat, open flames or comes into contact with oxidants; the waste salt obtained by conventional methods, which contains a large amount of organic anhydrides, cannot be directly discharged as a toxic dangerous substance according to the enterprise's safety production regulations, and there is also a risk of spontaneous combustion when it is stored in the open air at high temperatures in summer, creating an unstable dangerous source. Furthermore, as one of the important raw materials for synthesizing plasticizers, organic anhydride will increase production costs for the company itself if it is not utilized rationally to the maximum extent. Therefore, conventional plasticizer wastewater treatment equipment has defects and cannot be reasonably promoted and applied. Summary of the invention

[0004] In view of the shortcomings of the prior art, the utility model provides a plasticizer wastewater treatment device which can separate organic acid and sodium sulfate from plasticizer wastewater, facilitates further treatment of wastewater residue using existing wastewater treatment devices, improves the step-by-step recovery of organic acid and sodium sulfate, and thereby reduces the production cost of the enterprise, and is used to overcome the defects in the prior art.

[0005] The technical solution adopted by the utility model is: a plasticizer wastewater treatment device, comprising a wastewater delivery pipe, the outlet end of the wastewater delivery pipe is connected with a distillation tower, the distillation tower is provided with a reboiling circulation pipe, the reboiling circulation pipe is provided with a first stop valve, a first booster pump, a reboiler and a first online density meter in sequence along the direction from the inlet end of the reboiling circulation pipe to the outlet end of the reboiling circulation pipe, the reboiling circulation pipe between the first booster pump and the reboiler is connected with the inlet end of the first buffer tank, the outlet end of the first buffer tank is connected with an acidification reactor, the lower part of the acidification reactor is connected with the inlet end of a first centrifuge, the liquid phase outlet end of the first centrifuge is connected with a first concentration reactor, the outlet end of the first concentration reactor is connected with The second buffer tank is connected to the first concentration reactor through the first concentrated liquid delivery pipe, the first concentrated liquid delivery pipe is provided with a second concentrated liquid delivery pipe, the outlet end of the second concentrated liquid delivery pipe is connected with a third buffer tank, the third buffer tank is connected to the acidification reactor, the outlet end of the second buffer tank is sequentially connected with an electrolytic cell, a second concentration reactor, a crystallization tank and a second centrifuge; the third buffer tank is connected to the acidification reactor through a fourth concentrated liquid delivery pipe, the top of the acidification reactor is connected with a sulfuric acid storage tank, the sulfuric acid storage tank and the acidification reactor are connected through a sulfuric acid delivery pipe, and the sulfuric acid delivery pipe and the fourth concentrated liquid delivery pipe are respectively provided with a first liquid flow sensor and a seventh regulating valve.

[0006] Preferably, the distillation tower is provided with a first liquefied water delivery pipe, the first liquefied water delivery pipe is provided with a heat source channel of the second heat exchanger, the outlet end of the first liquefied water delivery pipe is provided with an alkali solution preparation tank, the first liquefied water delivery pipe between the alkali solution preparation tank and the second heat exchanger is provided with a second liquefied water delivery pipe, the first liquefied water delivery pipe between the second liquefied water delivery pipe and the alkali solution preparation tank and the second liquefied water delivery pipe are respectively provided with a first regulating valve, the alkali solution preparation tank is provided with a stirring device, and the alkali solution preparation tank, the acidification reactor and the first concentration reactor are respectively provided with an acidity meter.

[0007] Preferably, the distillation tower comprises a tower body, in which a first packing layer and a second packing layer are sequentially arranged from top to bottom, the tower body between the first packing layer and the second packing layer is connected to a wastewater delivery pipe, a cold source channel of a first heat exchanger is arranged on the wastewater delivery pipe, the inlet end of the heat source channel of the first heat exchanger is connected to the top of the tower body, a gas-liquid separation tank is connected to the outlet end of the heat source channel of the first heat exchanger, the liquid phase outlet end of the gas-liquid separation tank and the tower body above the first packing layer are connected through a crude alcohol reflux pipe, a second regulating valve is arranged on the crude alcohol reflux pipe, a crude alcohol delivery pipe is arranged on the crude alcohol reflux pipe between the second regulating valve and the gas-liquid separation tank, and a third regulating valve is arranged on the crude alcohol delivery pipe.

[0008] Preferably, the first concentrated liquid delivery pipe is provided with a second booster pump, a fourth regulating valve and a first check valve in sequence along the direction from the first concentrating reactor to the second buffer tank, the electrolyzer and the second buffer tank are connected through a third concentrated liquid delivery pipe, the third concentrated liquid delivery pipe is provided with a third booster pump and a fifth regulating valve in sequence along the direction from the second buffer tank to the electrolyzer, the third concentrated liquid delivery pipe between the third booster pump and the fourth regulating valve is connected to the first concentrated liquid delivery pipe between the first check valve and the second buffer tank through a concentrated liquid circulation pipe, the concentrated liquid circulation pipe is provided with a second stop valve and a second check valve in sequence along the third concentrated liquid delivery pipe to the first concentrated liquid delivery pipe, the first concentrated liquid delivery pipe between the second booster pump and the fourth regulating valve is connected to the inlet end of the second concentrated liquid delivery pipe, and a sixth regulating valve is provided on the second concentrated liquid delivery pipe.

[0009] Preferably, the liquid phase outlet end of the second centrifuge is connected with a first centrifugal liquid delivery pipe, a fifth buffer tank is arranged on the first centrifugal liquid delivery pipe, the fifth buffer tank and the second concentration reactor are connected through the second centrifugal liquid delivery pipe, a fifth booster pump and a second liquid flow sensor are arranged in sequence on the second centrifugal liquid delivery pipe along the direction from the fifth buffer tank to the second concentration reactor, a third centrifugal liquid delivery pipe is arranged on the second centrifugal liquid delivery pipe between the fifth buffer tank and the fifth booster pump, and an eighth regulating valve is respectively arranged on the second centrifugal liquid delivery pipe between the third centrifugal liquid delivery pipe and the second liquid flow sensor and on the third centrifugal liquid delivery pipe.

[0010] Preferably, the top of the cleaning tank is connected to the bottom of the first centrifuge, a third centrifuge is arranged above the cleaning tank, the inlet end of the third centrifuge and the bottom of the cleaning tank are connected through a cleaning delivery pipe, the cleaning delivery pipe is provided with a third stop valve, a fourth booster pump and a second online density meter, the solid phase outlet end of the third centrifuge is provided with a first solid material delivery pipe and a second solid material delivery pipe, the third centrifuge and the cleaning tank are connected through the second solid material delivery pipe, the first solid material delivery pipe and the second solid material delivery pipe are respectively provided with a fourth stop valve, the first centrifuge and the first concentration reactor are connected through a fourth centrifuge delivery pipe, a seventh buffer tank is provided on the fourth centrifuge delivery pipe, and the liquid phase outlet end of the third centrifuge is connected to the seventh buffer tank.

[0011] Preferably, the gas phase outlet end of the second concentration reactor is sequentially connected with a third liquefied water delivery pipe and a sixth buffer tank, the third liquefied water delivery pipe is provided with a third heat exchanger, the sixth buffer tank and the cleaning tank are connected through a fourth liquefied water delivery pipe, the fourth liquefied water delivery pipe is provided with a fifth liquefied water delivery pipe, and the fourth liquefied water delivery pipe between the fifth liquefied water delivery pipe and the cleaning tank and the fifth liquefied water delivery pipe are respectively provided with a ninth regulating valve.

[0012] The utility model has the following beneficial effects: firstly, the utility model realizes separation of the alcohol phase contained in the plasticizer wastewater and recovery as crude alcohol, thereby effectively recovering the alcohol raw material used for plasticizer production;

[0013] In addition, the organic acid as a solid can be separated from the distillation residue by gradual separation. The recovery of the organic acid can reduce the material loss of the organic acid while reducing the organic content in the solid after concentration and crystallization, thereby reducing the hazardous waste level of the solid. After the alcohol phase and the organic acid are separated, the residual liquid still contains a small amount of organic matter. The organic matter in the remaining residual liquid is removed by electrolysis in an electrolytic cell, so that the organic content in the residual liquid transported to the second concentration reactor for secondary concentration is approximately zero. The organic content in the residual liquid is greatly reduced, making the residual liquid easier to handle.

[0014] Secondly, the utility model performs secondary concentration in the second concentration reactor to form a secondary concentrated liquid, which is transported to a crystallization tank to be added with seed crystals for crystallization of sodium sulfate, thereby realizing the recovery of sodium sulfate.

[0015] Finally, the utility model will form an acidic concentrated liquid through a first concentration reactor, and transport a portion of the formed acidic concentrated liquid to the third buffer tank for temporary storage as one of the sources of acidic medium in the acidification reactor, thereby saving material consumption for treating plasticizer wastewater.

[0016] The utility model has the advantages of simple structure, convenient operation, ingenious design, greatly improved working efficiency, good social and economic benefits, and is a product that is easy to promote and use. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural schematic diagram of the utility model.

[0018] Figure 2 for Figure 1 A partial enlarged schematic diagram of detail A. DETAILED DESCRIPTION

[0019] Example 1: Figure 1 , 2As shown, a plasticizer wastewater treatment device includes a wastewater delivery pipe 1, the outlet end of the wastewater delivery pipe 1 is connected to a distillation tower, the distillation tower is provided with a reboiling circulation pipe 2, the distillation tower includes a tower body 25, a first packing layer 26 and a second packing layer 27 are sequentially arranged from top to bottom in the tower body 25, the tower body 25 between the first packing layer 26 and the second packing layer 27 is connected to the wastewater delivery pipe 1, a cold source channel of a first heat exchanger 28 is provided on the wastewater delivery pipe 1, and the first heat exchanger 2 The inlet end of the heat source channel 8 is connected to the top of the tower body 25, the outlet end of the heat source channel of the first heat exchanger 28 is connected to the gas-liquid separation tank 29, the liquid phase outlet end of the gas-liquid separation tank 29 is connected to the tower body 25 above the first packing layer 26 through a crude alcohol reflux pipe 30, a second regulating valve 31 is provided on the crude alcohol reflux pipe 30, a crude alcohol delivery pipe 32 is provided on the crude alcohol reflux pipe 30 between the second regulating valve 31 and the gas-liquid separation tank 29, and a third regulating valve 33 is provided on the crude alcohol delivery pipe 32. The inlet end of the reboiling circulation pipe 2 is located at the bottom end of the tower body 25, and the outlet end of the reboiling circulation pipe 2 is located on the tower body 25 between the inlet end of the reboiling circulation pipe 2 and the second packing layer 27; the reboiling circulation pipe 2 is provided with a first stop valve 3, a first booster pump 4, a reboiler 5, a temperature sensor 74 and a first online density meter 6 in sequence along the direction from the inlet end of the reboiling circulation pipe 2 to the outlet end of the reboiling circulation pipe 2; the reboiling circulation pipe 2 between the first booster pump 4 and the reboiler 5 is connected to the inlet end of the first buffer tank 7; the reboiling circulation pipe 2 and the first buffer tank 7 are connected through a fifth concentrated liquid delivery pipe 76; the reboiling circulation pipe 2 between the fifth concentrated liquid delivery pipe 76 and the reboiler 5 and the fifth concentrated liquid delivery pipe 76 are respectively provided with a tenth regulating valve 75; the outlet end of the first buffer tank 7 is connected to an acidification reactor 8, and the acidification reactor 8 is connected to the acidification reactor 8. The reactor 8 and the first buffer tank 7 are connected through the sixth concentrated liquid delivery pipe 77, and the sixth concentrated liquid delivery pipe 77 is provided with a sixth booster pump 78; the lower part of the acidification reactor 8 is connected with the inlet end of the first centrifuge 9, the liquid phase outlet end of the first centrifuge 9 is connected with the first concentration reactor 10, and the outlet end of the first concentration reactor 10 is connected with the second buffer tank 11, the second buffer tank 11 and the first concentration reactor 10 are connected through the first concentrated liquid delivery pipe 12, and the first concentrated liquid delivery pipe 12 is provided with a second concentrated liquid delivery pipe 13, and the outlet end of the second concentrated liquid delivery pipe 13 is connected with the third buffer tank 14, the third buffer tank 14 is connected with the acidification reactor 8, and the outlet end of the second buffer tank 11 is connected with the electrolytic cell 15, the second concentration reactor 16, the crystallization tank 17 and the second centrifuge 18 in sequence.

[0020] The acidification reactor 8, the first concentration reactor 10 and the second concentration reactor 16 are respectively provided with a pressure sensor 72, a temperature sensor 74 and a liquid level sensor 73. The acidification reactor 8, the first concentration reactor 10 and the second buffer tank 11 are respectively provided with an acidity meter 24.

[0021] The number of the acidification reactor 8, the second concentration reactor 16 and the crystallization tank 17 are all several, the several acidification reactors 8 are connected in parallel with each other, the several second concentration reactors 16 are connected in parallel with each other, and the several crystallization tanks 17 are connected in parallel with each other.

[0022] Before the formal start-up operation stage, a pre-operation process is required. In this case, the pre-operation process is divided into two stages, namely the first pre-operation process stage and the second pre-operation process stage. The first pre-operation process stage includes the following steps: S1: the wastewater generated in the plasticizer production system is transported from the wastewater transport pipe 1 through the cold source channel of the first heat exchanger 28 to the inner cavity of the tower body 25 between the first packing layer 26 and the second packing layer 27, and flows to the bottom of the tower body 25 through the second packing layer 27 due to gravity.

[0023] S2: The medium at the bottom of the tower body 25 enters the inlet end of the reboiling circulation pipe 2 and is pressurized by the first booster pump 4. All the wastewater entering the reboiling circulation pipe 2 moves along the inlet end of the reboiling circulation pipe 2 to the outlet end of the reboiling circulation pipe 2. During this period, it is heated by the reboiler 5 and then fed back by the first online density meter 6 to the mixed liquid density and the temperature sensor 74 to feed back the temperature. Then, it flows back to the bottom of the tower body 25 to form a heat source. A large amount of alcohol components and water components form a gas phase and flow along the second packing layer 27 to the top of the tower body 25. During this period, the rising steam and the wastewater in the inner cavity of the tower body 25 between the first packing layer 26 and the second packing layer 27 are countercurrently exchanged. The rising steam part is cooled and refluxed to the bottom of the tower. The alcohol component part contained in the wastewater is evaporated and flows to the tower body 25 through the first packing layer 26 along with the rising steam; the steam is a gaseous mixture of alcohol and water.

[0024] S3: The steam enters the heat source channel of the first heat exchanger 28 through the tower body 25 and performs heat exchange with the wastewater transported through the wastewater transport pipe 1 that enters the cold source channel of the first heat exchanger 28. The steam passing through the heat source channel of the first heat exchanger 28 is cooled, the alcohol phase and the water phase are liquefied, and a small amount of non-condensable gas is cooled; the wastewater transported through the wastewater transport pipe 1 that passes through the cold source channel of the first heat exchanger 28 is heated and then transported to the inner cavity of the tower body 25. The liquefied gas phase component enters the gas-liquid separation tank 29, and the non-condensable gas is discharged from the top of the gas-liquid separation tank 29 and sent to the industrial torch for combustion treatment. The liquid phase component is a liquid mixture of alcohol and water, which is enriched at the bottom of the gas-liquid separation tank 29 to form crude alcohol; a part of the crude alcohol is refluxed to the inner cavity of the tower body 25 above the first packing layer 26 through the crude alcohol reflux pipe 30 as another cold source and continuously descends under the action of gravity and the steam that continuously rises through the first packing layer 26 is countercurrently exchanged, and the water phase component in the steam is liquefied and then descends to the bottom of the tower body 25, and the alcohol phase in the liquid crude alcohol entering the inner cavity of the tower body 25 is evaporated and continuously rises, and the water phase continues to descend along the first packing layer 26 to the bottom of the tower body 25. Another part of the crude alcohol is transported to the crude alcohol distillation section through the crude alcohol delivery pipe 32 for crude alcohol distillation, and then the alcohol phase is recovered to save costs. When the value fed back by the first online density meter 6 is continuously stable to the preset range, the first pre-operation process stage can be ended.

[0025] The purpose of the first pre-operation process is to form a liquid residue with low alcohol content at the bottom of the tower body 25. The second pre-operation process can be carried out on the basis of the first stage pre-operation process. The second pre-operation process stage includes steps S1 to S3 of the first pre-operation process stage. However, the difference between step S2 of the second pre-operation process stage and step S2 of the first pre-operation process stage is that the wastewater entering the reboiling circulation pipe 2 is no longer all moved along the inlet end of the reboiling circulation pipe 2 to the outlet end of the reboiling circulation pipe 2; instead, part of the wastewater entering the reboiling circulation pipe 2 moves along the inlet end of the reboiling circulation pipe 2 to the outlet end of the reboiling circulation pipe 2. The liquid moves toward the outlet end of the circulation pipe 2, during which part is heated by the reboiler 5, and after the liquid composition is fed back by the first online density meter 6 and the temperature is fed back by the temperature sensor 74, it flows back to the bottom of the tower body 25 to form a heat source; another part is delivered to the first buffer tank 7 through the fifth concentrated liquid delivery pipe 76, and the distribution ratio of the part flowing back to the tower body 25 and the liquid delivered to the first buffer tank 7 is comprehensively adjusted by adjusting the opening of the tenth regulating valve 75 installed on the reboiler circulation pipe 2 between the fifth concentrated liquid delivery pipe 76 and the reboiler 5, and the opening of the tenth regulating valve 75 installed on the fifth concentrated liquid delivery pipe 76. Since a liquid residue with a low alcohol content is formed at the bottom of the tower body 25 during the first pre-operation process, in the step S2, the wastewater continuously transported to the inner cavity of the tower body 25 through the wastewater transport pipe 1 has a large amount of alcohol phase evaporated during the countercurrent heat exchange between the wastewater in the second packing layer 27 and the steam generated at the bottom of the tower body 25. The residual liquid falling to the bottom of the tower body 25 and the liquid refluxed from the bottom of the tower body 25 are mixed to form wastewater entering the reboiler circulation pipe 2, and the alcohol phase content of this part of wastewater is relatively low.

[0026] On the basis of the first stage pre-operation process, the second stage pre-operation process adds the following steps in sequence after step S3: S4: the concentrated liquid continues to enter the first buffer tank 7 through the fifth concentrated liquid delivery pipe 76 for temporary storage; the first buffer tank 7 delivers the concentrated liquid to the acidification reactor 8 through the sixth concentrated liquid delivery pipe 77 under the pressure of the sixth booster pump 78 according to the needs of the corresponding acidification reactor 8 to the preset liquid level of the acidification reactor 8.

[0027] S5: the acidification reactor 8 receives the wastewater delivered from the first buffer tank 7 and reaches the preset liquid level, and then a predetermined amount of sulfuric acid is added to the acidification reactor 8 to acidify the wastewater to form a strong acid environment with a pH value of no more than 2; then continuous stirring is performed, during which, after the wastewater is acidified, the organic acid component in the wastewater forms an organic acid solid that continuously precipitates to form a suspension, and after stirring for a preset time, it is transported to the first centrifuge 9 for solid-liquid separation, and the liquid phase component is transported to the first concentration reactor 10 through the liquid phase component outlet of the first centrifuge 9, and the solid phase component is discharged through the solid phase component outlet of the first centrifuge 9; in this step, the organic acid component forms a solid phase and is separated, and is discharged through the solid phase component outlet of the first centrifuge 9 for recycling and reuse.

[0028] S6: After the liquid entering the first concentration reactor 10 reaches the preset liquid level, it can be started. The first concentration reactor 10 concentrates the liquid entering the first concentration reactor 10 once to form an acidic concentrated liquid. The acidic concentrated liquid is divided into two parts: one part is transported to the third buffer tank 14, and the remaining part is transported to the second buffer tank 11 for temporary storage.

[0029] S7: adding sodium hydroxide lye to the second buffer tank 11 until the value fed back by the acidity meter 24 on the second buffer tank 11 is neutral, forming a neutral concentrated solution; transporting part of the neutral concentrated solution to the electrolytic cell 15 for electrolysis to remove the remaining organic matter contained during the period, forming a residual solution after electrolysis.

[0030] S8: The residual liquid after electrolysis is transported to the second concentration reactor 16 for secondary concentration to form a secondary concentrated liquid.

[0031] S9: The secondary concentrated liquid is transported to one of the crystallization tanks 17 that is waiting to receive the secondary concentrated liquid. After the transport is completed, a seed crystal is added to the crystallization tank 17 to crystallize sodium sulfate. The crystallization process is fully allowed to stand to form sodium sulfate crystals and residual liquid after crystallization. The sodium sulfate crystals are then transported to the second centrifuge 18 for solid-liquid separation. The sodium sulfate crystals are discharged from the solid phase outlet of the second centrifuge 18, and the residual liquid after crystallization is discharged from the liquid phase outlet of the second centrifuge 18.

[0032] After completing the above steps and the third buffer tank 14 reaches the preset liquid level, the second pre-operation process stage is completed, and the production steps of the formal start-up operation stage can be carried out, including steps S1 to S9 of the second pre-operation stage, but step S5 of the formal start-up operation stage is different from step S5 of the second pre-operation stage. The difference is that in step S5 of the formal operation stage, the source of the acidic medium in the acidification reactor 8 is partly derived from sulfuric acid added from the outside, and the other part is derived from the concentrated acidic concentrate stored in the third buffer tank 14.

[0033] Through Example 1, the alcohol phase contained in the plasticizer wastewater is separated and recovered as crude alcohol, and the alcohol raw material used for plasticizer production is effectively recovered; in addition, the organic acid as a solid is separated from the distillation residue by step-by-step separation, and the recovery of the organic acid reduces the material loss of the organic acid and also reduces the hazardous waste level of the solid after the concentration and crystallization. After the alcohol phase and the organic acid are separated, the residual liquid still contains a small amount of organic matter, and the remaining organic matter contained in the residual liquid is electrolyzed and removed by the electrolytic cell 15, so that it is transported to the second concentration reactor. The organic matter content in the residual liquid after the secondary concentration by 16 is approximately zero; the content of organic matter in the residual liquid is greatly reduced, making the residual liquid easier to handle; then, the second concentration reactor 16 performs secondary concentration to form a crystalline residual liquid and transports it to the crystallization tank 17 to add crystal seeds for crystallization of sodium sulfate, thereby realizing the recovery of sodium sulfate; finally, the first concentration reactor 10 performs a primary concentration to form an acidic concentrated liquid, and a part of the formed acidic concentrated liquid is transported to the third buffer tank 14 for temporary storage as one of the sources of the acidic medium in the acidification reactor 8, thereby saving the material consumption for treating plasticizer wastewater.

[0034] Embodiment 2, as Figure 1 and Figure 2 As shown, the difference from Example 1 is that Example 2 is provided with a first liquefied water delivery pipe 19 on the distillation tower on the basis of Example 1, a heat source channel of a second heat exchanger 20 is provided on the first liquefied water delivery pipe 19, an alkali solution preparation tank 21 is provided on the outlet end of the first liquefied water delivery pipe 19, a second liquefied water delivery pipe 22 is provided on the first liquefied water delivery pipe 19 between the alkali solution preparation tank 21 and the second heat exchanger 20, a first regulating valve 23 is provided on the first liquefied water delivery pipe 19 between the second liquefied water delivery pipe 22 and the alkali solution preparation tank 21 and on the second liquefied water delivery pipe 22, the bottom of the alkali solution preparation tank 21 is connected to the top of the second buffer tank 11, and the first regulating valve 23 is also installed on the connecting pipe between the alkali solution preparation tank 21 and the second buffer tank 11; the alkali solution preparation tank 21 is provided with a stirring device, and the alkali solution preparation tank 21 is also equipped with an acidity meter 24.

[0035] In step S1 to step S3 in Example 1, high-concentration water vapor is generated during the distillation process of the wastewater generated in the plasticizer production system in the distillation tower. In Example 2, it is transported outward through the first liquefied water delivery pipe 19, during which it passes through the heat source channel of the second heat exchanger 20 and the cold source continuously transported in the cold source channel of the second heat exchanger 20 for heat exchange. The water vapor described in the heat source channel of the second heat exchanger 20 is liquefied to form liquefied water, which is discharged from the outlet end of the heat source channel of the second heat exchanger 20 and continues to move along the first liquefied water delivery pipe 19 toward the alkali solution preparation tank 21, wherein a part of the liquefied water enters the alkali solution preparation tank 21, and another part of the liquefied water is transported to the biochemical treatment device through the second liquefied water delivery pipe 22 for treatment.

[0036] The liquefied water entering the alkali solution preparation tank 21 is used as a solvent for alkali solution preparation. A preset amount of sodium hydroxide is added according to the liquid level feedback on the alkali solution preparation tank 21 to form a sodium hydroxide solution of a preset concentration. The acidity value of the sodium hydroxide solution is fed back by the acidity meter 24 installed in the alkali solution preparation tank 21, which serves as the source of the sodium hydroxide alkali solution required by the second buffer tank 11 in step S7 in Example 1.

[0037] By comparing Example 2 with Example 1, Example 2 uses the liquefied water formed by liquefying the water vapor discharged from the distillation tower as the source of the sodium hydroxide lye required by the second buffer tank 11 in step S7 in Example 1. The liquefied water formed by liquefying the water vapor discharged from the distillation tower still contains a small amount of alcohol phase components, which is used as the source of the sodium hydroxide lye required by the second buffer tank 11 in step S7. The sodium hydroxide lye provided by the second buffer tank 11 is added to the second buffer tank 11 in a neutral state to form a neutral concentrated solution; after being transported to the electrolytic cell 15 for electrolysis, the additional alcohol phase components carried by this part of the solvent will be decomposed into inorganic components after the electrolysis process in the electrolytic cell 15. Although some electricity is consumed, the addition of foreign liquid phase medium in the wastewater treatment process is reduced, and the total amount of wastewater treated is reduced.

[0038] Embodiment 3, as Figure 1 and Figure 2 As shown, the difference from Example 1 is that in Example 4, based on Example 1, the third buffer tank 14 and the acidification reactor 8 are connected through a fourth concentrated liquid delivery pipe 44, a sulfuric acid storage tank 45 is connected above the acidification reactor 8, the sulfuric acid storage tank 45 and the acidification reactor 8 are connected through a sulfuric acid delivery pipe 46, and a first liquid flow sensor 47 and a seventh regulating valve 48 are respectively provided on the sulfuric acid delivery pipe 46 and the fourth concentrated liquid delivery pipe 44.

[0039] In addition, the difference from Example 1 is that in step S5 of the formal operation stage, part of the sulfuric acid in the acidification reactor 8 comes from the outside and is provided by the sulfuric acid storage tank 45 and transported through the sulfuric acid delivery pipe 46. The volume parameter of the sulfuric acid delivered to the acidification reactor 8 through the sulfuric acid delivery pipe 46 is fed back by the first liquid flow sensor 47 installed on the sulfuric acid delivery pipe 46; the acidic concentrated liquid from the third buffer tank 14 and delivered to the acidification reactor 8 is transported through the fourth concentrated liquid delivery pipe 44, and the volume parameter of the acidic concentrated liquid delivered to the acidification reactor 8 through the fourth concentrated liquid delivery pipe 44 is fed back by the first liquid flow sensor 47 installed on the fourth concentrated liquid delivery pipe 44.

[0040] By comparing Example 3 with Example 1, Example 3 facilitates feedback of the volume parameter of sulfuric acid delivered from the sulfuric acid storage tank 45 to the acidification reactor 8 by providing a sulfuric acid storage tank 45, a sulfuric acid delivery pipe 46, and a first liquid flow sensor 47 provided on the sulfuric acid delivery pipe 46; and facilitates feedback of the volume parameter of the acidic concentrated liquid delivered from the third buffer tank 14 to the acidification reactor 8 by providing a fourth concentrated liquid delivery pipe 44 and a first liquid flow sensor 47 installed on the fourth concentrated liquid delivery pipe 44.

[0041] Embodiment 4, as Figure 1 and Figure 2 As shown, the difference from Example 3 is that, on the basis of Example 3, the first concentrated liquid delivery pipe 12 is provided with a second booster pump 34, a fourth regulating valve 35 and a first check valve 36 in sequence along the direction from the first concentration reactor 10 to the second buffer tank 11, the electrolytic cell 15 and the second buffer tank 11 are connected through a third concentrated liquid delivery pipe 37, and the third concentrated liquid delivery pipe 37 is provided with a third booster pump 38 and a fifth regulating valve 39 in sequence along the direction from the second buffer tank 11 to the electrolytic cell 15, the third booster pump 38 and the fourth The third concentrated liquid delivery pipe 37 between the regulating valves 35 is connected with the first one-way valve 36 and the first concentrated liquid delivery pipe 12 between the second buffer tank 11 through a concentrated liquid circulation pipe 40. The concentrated liquid circulation pipe 40 is sequentially provided with a second stop valve 41 and a second one-way valve 42 along the third concentrated liquid delivery pipe 37 to the first concentrated liquid delivery pipe 12. The first concentrated liquid delivery pipe 12 between the second boosting pump 34 and the fourth regulating valve 35 is connected with the inlet end of the second concentrated liquid delivery pipe 13. The second concentrated liquid delivery pipe 13 is provided with a sixth regulating valve 43.

[0042] The difference from Example 3 is that step S6: the first concentration reactor 10 once concentrates the liquid entering the first concentration reactor 10 to form an acidic concentrated liquid, which is divided into two parts: one part is transported to the third buffer tank 14, and the part of the acidic concentrated liquid transported to the third buffer tank 14 is transported through the first concentrated liquid transport pipe 12 and the second concentrated liquid transport pipe 13, and is pressurized by the second booster pump 34 on the first concentrated liquid transport pipe 12; the remaining part is transported to the second buffer tank 11 for temporary storage, and the part transported to the second buffer tank 11 is pressurized by the second booster pump 34 and then transported through the first concentrated liquid transport pipe 12; the ratio between the acidic concentrated liquid transported to the second buffer tank 11 and the acidic concentrated liquid transported to the third buffer tank 14 is comprehensively adjusted by adjusting the opening of the fourth regulating valve 35 installed on the first concentrated liquid transport pipe 12 and adjusting the opening of the sixth regulating valve 43 installed on the second concentrated liquid transport pipe 13. It is worth mentioning that the liquid phase component separated by the first centrifuge 9 in step S5 of Example 3 is transported to the first concentration reactor 10, and part of the organic acid will still be dissolved in the liquid phase component. Then, in the process of concentrating the liquid phase component in the first concentration reactor 10, as the volume of the liquid phase component decreases, part of the organic acid will precipitate to form solid precipitation, that is, the acidic concentrated liquid transported by the first concentration reactor 10 to the third buffer tank 14 and the second buffer tank 11 is a suspension; the organic acid precipitate contained in the acidic concentrated liquid transported to the third buffer tank 14 and the acidification reactor 8 is collected again during the acidification process, thereby improving the recovery rate of the organic acid. To be more specific; the inlet end of the third concentrated liquid delivery pipe 37 is located above the bottom end of the second buffer tank 11, and a sewage pipe is provided on the bottom end of the second buffer tank 11, and a sewage stop valve is provided on the sewage pipe. The solid organic acid contained in the acidic concentrated liquid transported to the second buffer tank 11 is enriched at the bottom of the inner cavity of the second buffer tank 11. The sewage shut-off valve is opened regularly to discharge the acidic concentrated liquid containing organic acid from the second buffer tank 11 through the sewage pipe, and the organic acid precipitate is separated to obtain the organic acid to the greatest extent, thereby reducing the amount of organic matter decomposed by the electrolytic cell 15.

[0043] In addition, the difference from Example 3 is that in step S7, sodium hydroxide lye is added to the second buffer tank 11 until the value fed back by the acidity meter 24 on the second buffer tank 11 is neutral, and in the process of forming a neutral concentrated solution, in the process of the second buffer tank 11 receiving the sodium hydroxide lye, it is necessary to open the third booster pump 38 and the second stop valve 41 and close the fifth regulating valve 39. In the process of the second buffer tank 11 receiving the sodium hydroxide lye, the acidic concentrated solution entering the concentrated solution circulation pipe 40 through the third concentrated solution delivery pipe 37 is pressurized by the third booster pump 38, so that the acidic concentrated solution temporarily stored in the second buffer tank 11 passes through the third concentrated solution delivery pipe 37 and the concentrated solution circulation pipe 40 in turn, and finally flows back to the second buffer tank 11 to form a cycle.

[0044] By comparing Example 4 with Example 3, Example 3 provides a first concentrated liquid delivery pipe 12 and a second concentrated liquid delivery pipe 13, and installs a fourth regulating valve 35 on the first concentrated liquid delivery pipe 12, and a sixth regulating valve 43 on the second concentrated liquid delivery pipe 13, so as to facilitate adjustment of the ratio of the acidic concentrated liquid delivered to the second buffer tank 11 and the third buffer tank 14; in addition, a concentrated liquid circulation pipe 40 and a third concentrated liquid delivery pipe 37 are provided, and a third boosting pump 38 is installed on the third concentrated liquid delivery pipe 37, and the flow guidance function provided by the first one-way valve 36 installed on the first concentrated liquid delivery pipe 12 and the second one-way valve 42 installed on the concentrated liquid circulation pipe 40 is utilized. In the process of the second buffer tank 11 receiving the sodium hydroxide solution, after the third booster pump 38 is driven, the acidic concentrated liquid in the second buffer tank 11 flows back to the second buffer tank 11 through the concentrated liquid circulation pipe 40 to form a circulation, so that the acidic concentrated liquid in the second buffer tank 11 and the sodium hydroxide solution entering the second buffer tank 11 can be quickly mixed, thereby reducing the occurrence of the technical problem of excessive addition of sodium hydroxide solution.

[0045] Embodiment 5, as Figure 1 and Figure 2 As shown, the difference from Example 1 is that in Example 5, based on Example 1, the liquid phase outlet end of the second centrifuge 18 described in Example 1 is connected with a first centrifugal liquid delivery pipe 49, a fifth buffer tank 50 is arranged on the first centrifugal liquid delivery pipe 49, the fifth buffer tank 50 and the second concentration reactor 16 are connected through a second centrifugal liquid delivery pipe 51, a fifth booster pump 52 and a second liquid flow sensor 53 are sequentially arranged on the second centrifugal liquid delivery pipe 51 along the direction from the fifth buffer tank 50 to the second concentration reactor 16, a third centrifugal liquid delivery pipe 54 is arranged on the second centrifugal liquid delivery pipe 51 between the fifth buffer tank 50 and the fifth booster pump 52, and an eighth regulating valve 55 is respectively arranged on the second centrifugal liquid delivery pipe 51 between the third centrifugal liquid delivery pipe 54 and the second liquid flow sensor 53.

[0046] In addition, the difference from Example 1 is that after the residual liquid after crystallization is discharged from the liquid phase outlet of the second centrifuge 18 in step S9, the residual liquid after crystallization is transported to the fifth buffer tank 50 for temporary storage; a part of the residual liquid after crystallization in the fifth buffer tank 50 is discharged to the drying furnace through the third centrifugal liquid delivery pipe 54 for drying and collecting the residual inorganic solids, and the other part is transported to the second concentration reactor 16 through the second centrifugal liquid delivery pipe 51 and mixed with the residual liquid after electrolysis in the second concentration reactor 16 for secondary concentration to form a secondary concentrated liquid. And in step S9, it is transported to the crystallization tank 17 as the secondary concentrated liquid to add seed crystals for crystallization.

[0047] By comparing Example 5 with Example 1, Example 5 performs secondary concentration by re-transporting part of the residual liquid after crystallization back to the second concentration reactor 16, and mixing it with the residual liquid after electrolysis in the second concentration reactor 16, to form a secondary concentrated liquid, which is transported to the crystallization tank 17 for adding seed crystals for crystallization. Since the residual liquid after crystallization discharged from the liquid phase outlet of the second centrifuge 18 contains a high concentration of sodium sulfate solute, the above operation method improves the recovery rate of sodium sulfate.

[0048] Embodiment 6, as Figure 1 and Figure 2 As shown, the difference from Example 1 is that Example 6 is based on Example 1, and the top of the cleaning tank 59 is connected below the first centrifuge 9, the cleaning tank 59 is provided with a stirring device, and a third centrifuge 60 is provided above the cleaning tank 59. The inlet end of the third centrifuge 60 and the bottom of the cleaning tank 59 are connected through a cleaning delivery pipe 61, and the cleaning delivery pipe 61 is provided with a third stop valve 62, a fourth booster pump 63 and a second online density meter 64. The solid phase outlet end of the third centrifuge 60 is provided with a first solid material delivery pipe 65 and a second solid material delivery pipe 66, the third centrifuge 60 and the cleaning tank 59 are connected through the second solid material delivery pipe 66, and the first solid material delivery pipe 65 and the second solid material delivery pipe 66 are respectively provided with a fourth stop valve 67, the first centrifuge 9 and the first concentration reactor 10 are connected through a fourth centrifuge liquid delivery pipe 79, and the fourth centrifuge liquid delivery pipe 79 is provided with a seventh buffer tank 71, and the liquid phase outlet end of the third centrifuge 60 is connected to the seventh buffer tank 71. The gas phase outlet end of the second concentration reactor 16 is connected in sequence with a third liquefied water delivery pipe 56 and a sixth buffer tank 57, the third liquefied water delivery pipe 56 is provided with a third heat exchanger 58, the sixth buffer tank 57 and the cleaning tank 59 are connected through a fourth liquefied water delivery pipe 68, the fourth liquefied water delivery pipe 68 is provided with a fifth liquefied water delivery pipe 69, and the fourth liquefied water delivery pipe 68 between the fifth liquefied water delivery pipe 69 and the cleaning tank 59 and the fifth liquefied water delivery pipe 69 are respectively provided with a ninth regulating valve 70.

[0049] In addition, the difference from Example 1 is that the solid phase component in step S5 is discharged through the solid phase component outlet of the first centrifuge 9; the solid phase component is mostly composed of organic acid in solid form, carrying a small amount of impurities. After being discharged from the solid phase component outlet of the first centrifuge 9, it is transported to the cleaning tank 59 for temporary storage.

[0050] Another difference from Example 1 is that the steam generated by the secondary concentration process of the second concentration reactor 16 in step S8 does not contain organic matter in the residual liquid after electrolysis that enters the second concentration reactor 16 for secondary concentration. The steam generated in the secondary concentration process is basically pure water vapor. The steam generated in the secondary concentration process is liquefied to form liquefied water through heat exchange through the heat source channel of the third heat exchanger 58 and the cold source continuously transported by the cold source channel of the third heat exchanger 58. The formed liquefied water is transported to the sixth buffer tank 57 for temporary storage. The liquefied water temporarily stored in the sixth buffer tank 57 is transported to the cleaning tank 59 and is fully mixed with the solid organic acid transported to the cleaning tank 59 under the drive of the stirring device installed on the cleaning tank 59 to replace the impurities carried on the surface of the solid organic acid. Then the suspension is transported to the third centrifuge 60 for solid-liquid separation, and the liquid phase component is transported to the seventh buffer tank 71; the solid phase component is re-transported to the cleaning tank 59 through the second solid material conveying pipe 66, and then washed with the liquefied water temporarily stored in the sixth buffer tank 57. The above process is repeated many times until the value fed back by the second online density meter 64 on the cleaning conveying pipe 61 reaches the preset range and is then transported to the third centrifuge 60 for the last solid-liquid separation. The liquid phase is also transported to the seventh buffer tank 71, and the solid phase component after washing is discharged through the first solid material conveying pipe 65 for collection.

[0051] By comparing Example 6 with Example 1, Example 6 sets a cleaning tank 59, a third centrifuge 60, a sixth buffer tank 57, a third liquefied water delivery pipe 56, a fourth liquefied water delivery pipe 68 and a fifth liquefied water delivery pipe 69 to repeatedly clean the separated solid organic acid with the relatively pure water vapor generated in the wastewater treatment process. The liquid after repeated cleaning contains some organic matter, which is decomposed by the electrolytic cell 15. No additional wastewater that needs to be treated by other systems is generated during the cleaning process. In addition, after the sixth buffer tank 57 exceeds the warning water level, it can be directly discharged through the fifth liquefied water delivery pipe 69, and the amount of discharge is controlled by the ninth regulating valve 70 installed on the fifth liquefied water delivery pipe 69.

[0052] Example 7: Figure 1 and Figure 2As shown, the difference from Example 1 is that this example takes dioctyl phthalate wastewater as an example, and its anhydride is phthalic anhydride as an example. In this example, the wastewater is added to the acidification reactor 8 to form phthalic acid; the solubility of phthalic acid is 7g / L at 25°C. In the S5 step of the formal operation stage, the amount of the acidic medium composed of sulfuric acid and acid concentrate in the acidification reactor 8 is not the more the better. The relationship expressed in the following formula 1 should be satisfied:

[0053] Right now Wherein A1 is the parameter fed back by the acidometer 24 installed on the acidification reactor 8 for the wastewater containing organic acid which has not been acidified in the acidification reactor 8; 10 -A2 is the concentration of H+ when H+ in the concentrated sulfuric acid stored in the sulfuric acid storage tank 45 is completely hydrolyzed; 10 -A3 is the concentration of H+ when the acid solution concentrated by the first concentration reactor 10 and stored in the third buffer tank 14 is completely hydrolyzed; A4 is the parameter fed back by the acidity meter 24 installed on the wastewater acidification reactor 8 after acidification in the acidification reactor 8; is the concentration of phthalic anhydride in the wastewater containing organic acid that has not been acidified in the acidification reactor 8; λ is the coefficient; V1 is the volume of the wastewater containing organic acid that has not been acidified and is transported to the acidification reactor 8 via the first buffer tank 7; V2 is the volume of concentrated sulfuric acid that is transported to the acidification reactor 8 via the sulfuric acid storage tank 45; V3 is the volume of the concentrated acid solution that is transported to the acidification reactor 8 via the third buffer tank 14.

[0054] And the relationship expressed in the following formula 2 is satisfied:

[0055]

[0056] in, is the concentration of phthalic acid; K a1 is the coefficient of primary ionization of phthalic acid; is the concentration of monohydrogen phthalate, is the hydrogen ion concentration.

[0057] At the same time, phthalic acid will also have secondary ionization, but since the acid is excessive in this case and the final solution is a strong acid medium, the secondary ionization of phthalic acid can be ignored due to its extremely small amount. When phthalic anhydride forms phthalic acid and inhibits the hydrolysis degree of the generated phthalic acid in the strong acid medium, it will reduce the solubility of phthalic acid in the strong acid medium, thereby obtaining more phthalic acid, but the concentrated sulfuric acid stored in the sulfuric acid storage tank 45 and the acid stored in the third buffer tank 14 after being concentrated by the first concentration reactor 10 and added to the acidification reactor 8 should be controlled within a reasonable range, that is, the following relationship is obtained by combining formula 1 and formula 2:

[0058]

[0059] Wherein: A1 is the parameter fed back by the acidometer 24 installed on the acidification reactor 8 of the wastewater containing organic acid that has not been acidified in the acidification reactor 8; 10 -A2 is the concentration of H+ when H+ in the concentrated sulfuric acid stored in the sulfuric acid storage tank 45 is completely hydrolyzed; 10 -A3 is the H+ concentration when the acid solution concentrated by the first concentration reactor 10 and stored in the third buffer tank 14 is completely hydrolyzed; V1 is the volume of the wastewater containing organic acid that is not acidified and is delivered to the acidification reactor 8 via the first buffer tank 7; V2 is the volume of the concentrated sulfuric acid delivered to the acidification reactor 8 via the sulfuric acid storage tank 45; V3 is the volume of the concentrated acid solution delivered to the acidification reactor 8 via the third buffer tank 14; is the concentration of phthalic acid; K a1 is the coefficient of primary ionization of phthalic acid; is the concentration of monohydrogen phthalate; is the concentration of phthalic anhydride in the wastewater containing organic acid which has not been acidified in the acidification reactor 8; λ is the coefficient.

[0060] In this case, the total amount of concentrated sulfuric acid stored in the sulfuric acid storage tank 45 and the acid solution concentrated in the first concentration reactor 10 stored in the third buffer tank 14 added to the acidification reactor 8 is not the greater the better, but should meet a certain range. The reason is that when When the concentration is lower than the preset concentration, the continued addition of concentrated sulfuric acid and / or concentrated acid solution will increase the total volume of the solution, that is, the phthalic acid that has been precipitated will be redissolved due to the increase in the total volume of the solution.

[0061] The embodiments described above are only preferred embodiments of the present invention and are not intended to limit the scope of implementation of the present invention. Therefore, any equivalent changes or modifications made based on the structures, features and principles described in the patent scope of the present invention should be included in the patent application scope of the present invention.

Claims

1. A plasticizer wastewater treatment device, characterized in that: The invention comprises a wastewater conveying pipe (1), the outlet end of the wastewater conveying pipe (1) is connected to a distillation tower, the distillation tower is provided with a reboiling circulation pipe (2), the reboiling circulation pipe (2) is provided with a first stop valve (3), a first booster pump (4), a reboiler (5) and a first online density meter (6) in sequence along the direction from the inlet end of the reboiling circulation pipe (2) to the outlet end of the reboiling circulation pipe (2), the reboiling circulation pipe (2) between the first booster pump (4) and the reboiler (5) is connected to the inlet end of a first buffer tank (7), the outlet end of the first buffer tank (7) is connected to an acidification reactor (8), the lower part of the acidification reactor (8) is connected to the inlet end of a first centrifuge (9), the liquid phase outlet end of the first centrifuge (9) is connected to a first concentration reactor (10), the outlet end of the first concentration reactor (10) is connected to a second buffer tank (11), and a liquid phase outlet end of the first centrifuge (9) is connected to a first concentration reactor (10), and a liquid phase outlet end of the first concentration reactor (10) is connected to a second buffer tank (11), and a liquid phase outlet end of the first centrifuge (9) is connected to a first concentration reactor (10). The first concentrated liquid delivery pipe (12) is connected to the second concentrated liquid delivery pipe (13), the outlet end of the second concentrated liquid delivery pipe (13) is connected to a third buffer tank (14), the third buffer tank (14) is connected to the acidification reactor (8), and the outlet end of the second buffer tank (11) is connected to an electrolytic cell (15), a second concentrated reactor (16), a crystallization tank (17) and a second centrifuge (18) in sequence; the third buffer tank (14) and the acidification reactor (8) are connected to each other through a fourth concentrated liquid delivery pipe (44), a sulfuric acid storage tank (45) is connected above the acidification reactor (8), the sulfuric acid storage tank (45) and the acidification reactor (8) are connected to each other through a sulfuric acid delivery pipe (46), and a first liquid flow sensor (47) and a seventh regulating valve (48) are respectively provided on the sulfuric acid delivery pipe (46) and the fourth concentrated liquid delivery pipe (44).

2. The plasticizer wastewater treatment device according to claim 1, characterized in that: The distillation tower is provided with a first liquefied water delivery pipe (19), a heat source channel of a second heat exchanger (20) is provided on the first liquefied water delivery pipe (19), an alkali solution preparation tank (21) is provided at the outlet end of the first liquefied water delivery pipe (19), a second liquefied water delivery pipe (22) is provided on the first liquefied water delivery pipe (19) between the alkali solution preparation tank (21) and the second heat exchanger (20), first regulating valves (23) are provided on the first liquefied water delivery pipe (19) between the second liquefied water delivery pipe (22) and the alkali solution preparation tank (21) and on the second liquefied water delivery pipe (22), the alkali solution preparation tank (21) is provided with a stirring device, and the alkali solution preparation tank (21), the acidification reactor (8), and the first concentration reactor (10) are provided with acidity meters (24) respectively.

3. The plasticizer wastewater treatment device according to claim 1, characterized in that: The distillation tower comprises a tower body (25), wherein a first packing layer (26) and a second packing layer (27) are sequentially arranged in the tower body (25) from top to bottom, the tower body (25) between the first packing layer (26) and the second packing layer (27) is connected to a wastewater delivery pipe (1), a cold source channel of a first heat exchanger (28) is arranged on the wastewater delivery pipe (1), an inlet end of the heat source channel of the first heat exchanger (28) is connected to the top of the tower body (25), and the heat source channel of the first heat exchanger (28) is connected to the top of the tower body (25). The outlet end of the source channel is connected to a gas-liquid separation tank (29), the liquid phase outlet end of the gas-liquid separation tank (29) and the tower body (25) above the first packing layer (26) are connected via a crude alcohol reflux pipe (30), a second regulating valve (31) is provided on the crude alcohol reflux pipe (30), a crude alcohol delivery pipe (32) is provided on the crude alcohol reflux pipe (30) between the second regulating valve (31) and the gas-liquid separation tank (29), and a third regulating valve (33) is provided on the crude alcohol delivery pipe (32).

4. The plasticizer wastewater treatment device according to claim 1, characterized in that: The first concentrated liquid delivery pipe (12) is provided with a second booster pump (34), a fourth regulating valve (35) and a first check valve (36) in sequence along the direction from the first concentration reactor (10) to the second buffer tank (11); the electrolytic cell (15) and the second buffer tank (11) are connected via a third concentrated liquid delivery pipe (37); the third concentrated liquid delivery pipe (37) is provided with a third booster pump (38) and a fifth regulating valve (39) in sequence along the direction from the second buffer tank (11) to the electrolytic cell (15); the third concentrated liquid delivery pipe (37) is provided with a third booster pump (38) and a fifth regulating valve (39) in sequence along the direction from the second buffer tank (11) to the electrolytic cell (15); The first concentrated liquid delivery pipe (12) between the delivery pipe (37) and the first non-return valve (36) and the second buffer tank (11) is connected via a concentrated liquid circulation pipe (40); the concentrated liquid circulation pipe (40) is provided with a second stop valve (41) and a second non-return valve (42) in sequence along the third concentrated liquid delivery pipe (37) to the first concentrated liquid delivery pipe (12); the first concentrated liquid delivery pipe (12) between the second boosting pump (34) and the fourth regulating valve (35) is connected to the inlet end of the second concentrated liquid delivery pipe (13); and a sixth regulating valve (43) is provided on the second concentrated liquid delivery pipe (13).

5. The plasticizer wastewater treatment device according to claim 1, characterized in that: The liquid phase outlet end of the second centrifuge (18) is connected to a first centrifugal liquid delivery pipe (49), a fifth buffer tank (50) is arranged on the first centrifugal liquid delivery pipe (49), the fifth buffer tank (50) and the second concentration reactor (16) are connected via a second centrifugal liquid delivery pipe (51), a fifth booster pump (52) and a second liquid flow sensor (53) are arranged in sequence on the second centrifugal liquid delivery pipe (51) along the direction from the fifth buffer tank (50) to the second concentration reactor (16), a third centrifugal liquid delivery pipe (54) is arranged on the second centrifugal liquid delivery pipe (51) between the fifth buffer tank (50) and the fifth booster pump (52), and an eighth regulating valve (55) is respectively arranged on the second centrifugal liquid delivery pipe (51) between the third centrifugal liquid delivery pipe (54) and the second liquid flow sensor (53) and on the third centrifugal liquid delivery pipe (54).

6. The plasticizer wastewater treatment device according to claim 1, characterized in that: The first centrifuge (9) is connected to the top of the cleaning tank (59) below, and a third centrifuge (60) is arranged above the cleaning tank (59). The inlet end of the third centrifuge (60) and the bottom of the cleaning tank (59) are connected through a cleaning delivery pipe (61). The cleaning delivery pipe (61) is provided with a third stop valve (62), a fourth booster pump (63) and a second online density meter (64). The solid phase outlet end of the third centrifuge (60) is provided with a first solid material delivery pipe (65) and a second solid material delivery pipe (66), the third centrifuge (60) and the cleaning tank (59) are connected via a second solid material delivery pipe (66), the first solid material delivery pipe (65) and the second solid material delivery pipe (66) are respectively provided with a fourth stop valve (67), the first centrifuge (9) and the first concentration reactor (10) are connected via a fourth centrifuge liquid delivery pipe (79), a seventh buffer tank (71) is provided on the fourth centrifuge liquid delivery pipe (79), and the liquid phase outlet of the third centrifuge (60) is connected to the seventh buffer tank (71).

7. The plasticizer wastewater treatment device according to claim 6, characterized in that: The gas phase outlet end of the second concentration reactor (16) is connected in sequence to a third liquefied water delivery pipe (56) and a sixth buffer tank (57); the third liquefied water delivery pipe (56) is provided with a third heat exchanger (58); the sixth buffer tank (57) and the cleaning tank (59) are connected via a fourth liquefied water delivery pipe (68); a fifth liquefied water delivery pipe (69) is provided on the fourth liquefied water delivery pipe (68); the fourth liquefied water delivery pipe (68) between the fifth liquefied water delivery pipe (69) and the cleaning tank (59) and the fifth liquefied water delivery pipe (69) are both provided with a ninth regulating valve (70).

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