A method for reducing the hydrogen peroxide content of wastewater containing hydrogen peroxide

Abstract

This invention relates to a method for reducing the hydrogen peroxide content in wastewater containing hydrogen peroxide. Specifically, this invention provides a method for reducing the hydrogen peroxide content in wastewater, the method comprising: (1) providing wastewater containing hydrogen peroxide; (2) mixing the wastewater containing hydrogen peroxide from step (1) with an alkaline solution and reacting it to obtain a reaction solution; (3) adding the reaction solution from step (2) to a gas-liquid separator, and after gas-liquid separation, mixing the obtained liquid with an aqueous solution of sodium sulfite or sodium bisulfite and reacting it to reduce the hydrogen peroxide content in the wastewater. The method described in this invention can significantly reduce the hydrogen peroxide content in wastewater containing hydrogen peroxide.

Description

Technical Field

[0001] This invention relates to the field of chemical engineering, and specifically to a method for reducing the hydrogen peroxide content in wastewater containing hydrogen peroxide. Background Technology

[0002] Many industrial chemical reactions require hydrogen peroxide as an oxidant. For example, isoterpinene-4,8-epoxide is commonly prepared industrially through the epoxidation of isoterpinene. This isoterpinene-4,8-epoxide can then be further used to generate active ingredients such as the high-value chemical product terpinene-4-ol. Hydrogen peroxide is frequently used as an oxidant in the epoxidation of isoterpinene to prepare isoterpinene-4,8-epoxide. In chemical reactions involving hydrogen peroxide as an oxidant, an excess of hydrogen peroxide is generally used, resulting in a high hydrogen peroxide content in the wastewater after the reaction. Because hydrogen peroxide has a strong oxidizing effect, direct discharge into wastewater treatment systems can kill activated sludge and inactivate microorganisms, affecting the treatment efficiency of the wastewater treatment system and severely impacting its normal operation. Therefore, pretreatment to reduce the hydrogen peroxide content in wastewater before it enters the wastewater treatment system is crucial.

[0003] Therefore, there is a need in the field to develop a method for reducing the hydrogen peroxide content in wastewater containing hydrogen peroxide. Summary of the Invention

[0004] The purpose of this invention is to provide a method for reducing the hydrogen peroxide content in wastewater containing hydrogen peroxide.

[0005] The first aspect of this invention provides a method for reducing the hydrogen peroxide content in wastewater, the method comprising:

[0006] (1) Provides a wastewater containing hydrogen peroxide;

[0007] (2) The wastewater containing hydrogen peroxide from step (1) is mixed with an alkaline solution and reacted to obtain a reaction solution;

[0008] (3) The reaction liquid from step (2) is added to the gas-liquid separator. After gas-liquid separation, the resulting liquid is mixed with sodium sulfite aqueous solution or sodium bisulfite aqueous solution and reacted to reduce the hydrogen peroxide content in the wastewater.

[0009] Preferably, in step (1), the wastewater containing hydrogen peroxide is prepared by the following method:

[0010] Isopyrene, trifluoroacetophenone and hydrogen peroxide were mixed and reacted. After the reaction was completed, the mixture was separated into layers, and the water layer was separated to obtain wastewater containing hydrogen peroxide.

[0011] Preferably, in step (1), the reaction temperature is 30-70°C, more preferably 40-60°C, even more preferably 45-55°C, even more preferably 48-52°C, and most preferably 50°C.

[0012] Preferably, in step (1), the reaction time is 2-4 hours, more preferably 2.5-3.5 hours, even more preferably 2.8-3.2 hours, and most preferably 3 hours.

[0013] Preferably, in step (1), the mass ratio of trifluoroacetophenone to isoterpinene is (1-5):1, more preferably (2-4):1, even more preferably (2.5-3.5):1, even more preferably (2.8-3.2):1, and most preferably 3:1.

[0014] Preferably, in step (1), the mass ratio of hydrogen peroxide to isoterpinene is (0.3-2):1, more preferably (0.5-1.5):1, even more preferably (0.6-1.2):1, even more preferably (0.8-1.0):1, and most preferably 0.9:1.

[0015] Preferably, in step (1), the hydrogen peroxide is 20-40% hydrogen peroxide, more preferably 25-35% hydrogen peroxide, even more preferably 28-32% hydrogen peroxide, and most preferably 30% hydrogen peroxide.

[0016] Preferably, in step (1), the wastewater containing hydrogen peroxide is prepared by the following method:

[0017] Add 30.0g of isoprene and 90.1g of trifluoroacetophenone to a three-necked flask, heat to 50℃, add 27.1g of 30% hydrogen peroxide, and react at 50℃ for 3 hours. After the reaction is completed, separate the water layer to obtain wastewater containing hydrogen peroxide.

[0018] Preferably, in step (2), the alkaline solution is selected from aqueous solutions of the following alkaline reagents: sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, or combinations thereof.

[0019] Preferably, in step (2), the alkaline solution comprises an aqueous solution of hydroxide.

[0020] Preferably, the hydroxide is selected from the group consisting of sodium hydroxide, potassium hydroxide, or a combination thereof.

[0021] Preferably, in step (2), the alkaline solution comprises an aqueous solution of sodium hydroxide.

[0022] Preferably, the hydroxide content in the aqueous hydroxide solution is 5-40 wt%, more preferably 10-30 wt%, more preferably 15-25 wt%, more preferably 18-22 wt%, more preferably 19-21 wt%, and most preferably 15 wt% or 20 wt%.

[0023] Preferably, the sodium hydroxide content in the aqueous sodium hydroxide solution is 5-40 wt%, more preferably 10-30 wt%, more preferably 15-25 wt%, more preferably 18-22 wt%, more preferably 19-21 wt%, and most preferably 15 wt% or 20 wt%.

[0024] Preferably, in step (2), the mass ratio of the wastewater containing hydrogen peroxide to the alkaline solution is (15-35):1, more preferably (10-30):1, even more preferably (15-25):1, even more preferably (18-22):1, and most preferably 20:1 or 10:1.

[0025] Preferably, in step (2), the content of the alkaline reagent in the mixture of hydrogen peroxide-containing wastewater and alkaline solution in step (1) is 0.3-5 wt%, more preferably 0.5-2 wt%, more preferably 0.9-1.4 wt%, and most preferably 0.95 wt% or 1.36 wt%.

[0026] Preferably, in step (2), the reaction temperature is 60-100℃, more preferably 80-100℃, even more preferably 90-100℃, even more preferably 93-97℃, and most preferably 95℃.

[0027] Preferably, in step (2), the reaction time is 20-40 min, more preferably 25-35 min, even more preferably 28-32 min, and most preferably 30 min or 20 min.

[0028] Preferably, in step (2), the reaction is carried out in a tubular reactor.

[0029] Preferably, in step (2), the wastewater containing hydrogen peroxide and the alkaline solution from step (1) are mixed in a tubular reactor and then reacted in the tubular reactor.

[0030] Preferably, in step (3), the sodium sulfite content in the sodium sulfite aqueous solution is 3-30 wt%, more preferably 3-20 wt%, more preferably 4-16 wt%, more preferably 5-15 wt%, more preferably 8-12 wt%, and most preferably 10 wt% or 20 wt%.

[0031] Preferably, in step (3), the sodium bisulfite content in the sodium bisulfite aqueous solution is 3-40 wt%, more preferably 3-30 wt%, more preferably 5-25 wt%, more preferably 10-20 wt%, more preferably 13-17 wt%, and most preferably 15 wt%.

[0032] Preferably, in step (3), the mass ratio of the liquid obtained after gas-liquid separation to the sodium sulfite aqueous solution or sodium bisulfite aqueous solution is (1-25):1, more preferably (3-20):1, more preferably (5-15):1, more preferably (8-13):1, even more preferably (10-12):1, even more preferably (10.5-11):1, and most preferably 11:1 or 10.5:3.

[0033] Preferably, in step (3), the reaction temperature is 50-100℃, more preferably 60-100℃, even more preferably 80-100℃, even more preferably 90-100℃, even more preferably 93-97℃, and most preferably 65℃ or 95℃.

[0034] Preferably, in step (3), the reaction time is 10-40 min, more preferably 15-35 min, even more preferably 20-30 min, even more preferably 23-27 min, and most preferably 25 min or 30 min.

[0035] Preferably, in step (3), the reaction is carried out in a tubular reactor.

[0036] Preferably, in step (3), the liquid obtained after gas-liquid separation is mixed with an aqueous solution of sodium sulfite or an aqueous solution of sodium bisulfite in a tubular reactor, and then the reaction is carried out in the tubular reactor.

[0037] It should be understood that, within the scope of this invention, the above-described technical features of this invention and the technical features specifically described below (such as in the embodiments) can be combined with each other to form new or preferred technical solutions. Detailed Implementation

[0038] This invention develops a method for reducing the hydrogen peroxide content in wastewater containing hydrogen peroxide. The method includes mixing the wastewater containing hydrogen peroxide with an alkaline solution and reacting it to obtain a reaction liquid. The reaction liquid is then added to a gas-liquid separator. After gas-liquid separation, the resulting liquid is mixed with an aqueous solution of sodium sulfite or sodium bisulfite and reacted to reduce the hydrogen peroxide content in the wastewater.

[0039] the term

[0040] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0041] As used herein, the terms “comprising,” “including,” and “containing” are used interchangeably and include not only open-ended definitions but also semi-closed and closed definitions. The terms include “consisting of” and “substantially consisting of”.

[0042] As used herein, the term "wt%" refers to a percentage by weight. For example, "5wt% sodium bisulfite aqueous solution" means that the sodium bisulfite in the aqueous solution is 5% by weight, and so on.

[0043] As used in this article, the structure of the term "isoterpinene" is as follows:

[0044]

[0045] The structure of trifluoroacetophenone is as follows:

[0046]

[0047] As used herein, the structure of the term "isoterpinene-4,8-epoxide" is as follows:

[0048]

[0049] method

[0050] This invention provides a method for reducing the hydrogen peroxide content in wastewater, the method comprising:

[0051] (1) Provides a wastewater containing hydrogen peroxide;

[0052] (2) The wastewater containing hydrogen peroxide from step (1) is mixed with an alkaline solution and reacted to obtain a reaction solution;

[0053] (3) The reaction liquid from step (2) is added to the gas-liquid separator. After gas-liquid separation, the resulting liquid is mixed with sodium sulfite aqueous solution or sodium bisulfite aqueous solution and reacted to reduce the hydrogen peroxide content in the wastewater.

[0054] Specifically, the method described in this invention is as described in the first aspect of this invention above.

[0055] The main technical effects of this invention include:

[0056] This invention develops a method to reduce the hydrogen peroxide content in wastewater containing hydrogen peroxide, particularly a method to significantly reduce the hydrogen peroxide content in wastewater containing high levels of hydrogen peroxide generated during the epoxidation reaction of isoterpinene to prepare isoterpinene-4,8-epoxide. This avoids the problem of activated sludge in the biological system being killed and microorganisms in the wastewater treatment system being deactivated after the wastewater containing high levels of hydrogen peroxide is discharged into the wastewater treatment system, thus ensuring the normal operation of the wastewater treatment system.

[0057] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention.

[0058] Example

[0059] The structure of isoprene is as follows:

[0060]

[0061] The structure of trifluoroacetophenone is as follows:

[0062]

[0063] The structure of isoprene-4,8-epoxide is as follows:

[0064]

[0065] Example 1

[0066] This embodiment 1 provides a method for reducing the hydrogen peroxide content in wastewater generated from the epoxidation reaction of isoprene under hydrogen peroxide oxidant conditions, as detailed below:

[0067] (1) Add 30.0g of isoprene and 90.1g of trifluoroacetophenone to a three-necked flask, heat to 50°C, add 27.1g of 30% hydrogen peroxide, react at 50°C for 3h, and after the reaction is completed, separate the water layer to obtain wastewater containing hydrogen peroxide.

[0068] (2) The wastewater containing hydrogen peroxide obtained in step (1) and 20wt% sodium hydroxide aqueous solution are fed into a tubular reactor at a mass ratio of 10:0.5. The reaction temperature in the tubular reactor is controlled at 95℃ by heat transfer oil. The residence time of the mixture in the tubular reactor is 30min to obtain the reaction solution.

[0069] (3) The reaction liquid from step (2) is added to the gas-liquid separator. After separation by the gas-liquid separator, the liquid is discharged from the bottom of the gas-liquid separator and pumped into the tubular reactor at a mass ratio of 11:1 with a 10wt% sodium sulfite aqueous solution. The reaction temperature in the tubular reactor is controlled at 95℃ by heat transfer oil. The residence time of the mixture in the tubular reactor is 25min. The hydrogen peroxide content in the resulting wastewater is 0.08%, which can be directly discharged into the sewage treatment system.

[0070] Example 2

[0071] This embodiment 2 provides a method for reducing the hydrogen peroxide content in wastewater generated from the epoxidation reaction of isoprene under hydrogen peroxide oxidant conditions, as detailed below:

[0072] (1) Add 30.0g of isoprene and 90.1g of trifluoroacetophenone to a three-necked flask, heat to 50°C, add 27.1g of 30% hydrogen peroxide, react at 50°C for 3h, and after the reaction is completed, separate the water layer to obtain wastewater containing hydrogen peroxide.

[0073] (2) The wastewater containing hydrogen peroxide obtained in step (1) and 15wt% potassium hydroxide aqueous solution are fed into a tubular reactor at a mass ratio of 10:1. The reaction temperature in the tubular reactor is controlled at 95℃ by heat transfer oil. The residence time of the mixture in the tubular reactor is 20min to obtain the reaction solution.

[0074] (3) The reaction liquid from step (2) is added to a gas-liquid separator. After separation in the gas-liquid separator, the liquid is discharged from the bottom of the gas-liquid separator and pumped into a tubular reactor at a mass ratio of 11:1 with a 15wt% sodium bisulfite aqueous solution. The reaction temperature in the tubular reactor is controlled at 95℃ by heat transfer oil. The residence time of the mixture in the tubular reactor is 25min. The hydrogen peroxide content in the resulting wastewater is 0.12%.

[0075] Example 3

[0076] This embodiment 3 provides a method for reducing the hydrogen peroxide content in wastewater generated from the epoxidation reaction of isoprene under hydrogen peroxide oxidant conditions, as detailed below:

[0077] (1) Add 30.0g of isoprene and 90.1g of trifluoroacetophenone to a three-necked flask, heat to 50°C, add 27.1g of 30% hydrogen peroxide, react at 50°C for 3h, and after the reaction is completed, separate the water layer to obtain wastewater containing hydrogen peroxide.

[0078] (2) The wastewater containing hydrogen peroxide obtained in step (1) and 10wt% sodium hydroxide aqueous solution are fed into a tubular reactor at a mass ratio of 10:3. The reaction temperature of the tubular reactor is controlled at 75℃ by heat transfer oil. The residence time of the mixture in the tubular reactor is 25min to obtain the reaction solution.

[0079] (3) The reaction liquid from step (2) is added to a gas-liquid separator. After separation in the gas-liquid separator, the liquid is discharged from the bottom of the gas-liquid separator and pumped into a tubular reactor at a mass ratio of 11:1 with a 10wt% sodium sulfite aqueous solution. The reaction temperature in the tubular reactor is controlled at 95℃ by heat transfer oil. The residence time of the mixture in the tubular reactor is 25min. The hydrogen peroxide content in the resulting wastewater is 0.35%.

[0080] Example 4

[0081] Example 4 provides a method for reducing the hydrogen peroxide content in wastewater generated from the epoxidation reaction of isoprene under hydrogen peroxide oxidant conditions, as detailed below:

[0082] (1) Add 30.0g of isoprene and 90.1g of trifluoroacetophenone to a three-necked flask, heat to 50°C, add 27.1g of 30% hydrogen peroxide, react at 50°C for 3h, and after the reaction is completed, separate the water layer to obtain wastewater containing hydrogen peroxide.

[0083] (2) The wastewater containing hydrogen peroxide obtained in step (1) and 15wt% sodium hydroxide aqueous solution are fed into a tubular reactor at a mass ratio of 10:0.5. The reaction temperature of the tubular reactor is controlled at 60℃ by heat transfer oil. The residence time of the mixture in the tubular reactor is 20min to obtain the reaction solution.

[0084] (3) The reaction liquid from step (2) is added to a gas-liquid separator. After separation by the gas-liquid separator, the liquid is discharged from the bottom of the gas-liquid separator and fed into a tubular reactor at a mass ratio of 10.5:3 with a 20wt% sodium sulfite aqueous solution. The reaction temperature in the tubular reactor is controlled at 65℃ by heat transfer oil. The residence time of the mixture in the tubular reactor is 30min. The hydrogen peroxide content in the resulting wastewater is 0.46%.

[0085] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A method for reducing the hydrogen peroxide content in wastewater, characterized in that, The method includes: (1) Provides a wastewater containing hydrogen peroxide; (2) The wastewater containing hydrogen peroxide from step (1) is mixed with an alkaline solution and reacted to obtain a reaction solution; (3) The reaction liquid from step (2) is added to the gas-liquid separator. After gas-liquid separation, the resulting liquid is mixed with sodium sulfite aqueous solution and reacted to reduce the hydrogen peroxide content in the wastewater. In step (1), the wastewater containing hydrogen peroxide is prepared by the following method: Isoprene, trifluoroacetophenone and hydrogen peroxide are mixed and reacted. After the reaction is completed, the mixture is separated into layers, and the water layer is separated to obtain wastewater containing hydrogen peroxide. In step (2), the alkaline solution comprises an aqueous solution of hydroxide, wherein the hydroxide is selected from the group consisting of sodium hydroxide, potassium hydroxide, or a combination thereof; and the content of the hydroxide in the aqueous solution of hydroxide is 20 wt%. In step (2), the mass ratio of the wastewater containing hydrogen peroxide to the alkaline solution is 20:1; In step (2), the reaction temperature is 95°C; In step (2), the reaction time is 30 minutes; In step (3), the sodium sulfite content in the sodium sulfite aqueous solution is 10 wt%. In step (3), the mass ratio of the liquid obtained after gas-liquid separation to the sodium sulfite aqueous solution is 11:1; In step (3), the reaction temperature is 95°C; In step (3), the reaction time is 25 minutes.

2. The method as described in claim 1, characterized in that, In step (1), the wastewater containing hydrogen peroxide is prepared by the following method: Add 30.0g of isoprene and 90.1g of trifluoroacetophenone to a three-necked flask, heat to 50℃, add 27.1g of 30% hydrogen peroxide, and react at 50℃ for 3 hours. After the reaction is completed, separate the water layer to obtain wastewater containing hydrogen peroxide.

Images