Method for recycling and resource utilization of acephate acetylmethylamine phosphorylation wastewater

Abstract

The present application relates to wastewater treatment technical field, particularly to a kind of acetyl methyl amine phosphorus acylation wastewater circulation and resource utilization method, its main content is to first acetyl methyl amine phosphorus acylation wastewater is concentrated to recover the organic matter methanol and dichloromethane in wastewater, the first mother liquor after concentration is cooled crystallization and separation ammonium sulfate, again alkaline solution is reacted with the first mother liquor, ammonia gas produced by heating reaction liquid can be recycled for the neutralization process of acetylation or with water absorption to make ammonia water, after deamination the reaction liquid cooling crystallization obtains sodium acetate trihydrate and second mother liquor, second mother liquor is recycled for the back extraction water of acetyl methyl amine phosphorus after decoloring, this method not only recovers the solvent methanol and dichloromethane in acetyl methyl amine phosphorus acylation wastewater, but also recycles ammonia in the neutralization process of acetylation reaction, and the product quality of sodium acetate trihydrate obtained by crystallization can reach national standard.

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment technology, and in particular to a method for recycling and resource utilization of acetylmethylamine phosphorylated wastewater. Background Technology

[0002] In the production of acephate, isomerization and acetylation yield acephate crude oil. This crude oil is neutralized with ammonia and water, then extracted with dichloromethane. The organic phase undergoes solvent removal, crystallization, and filtration to obtain acephate crystals. The raffinate phase is acephate acylation wastewater containing ammonium acetate and a small amount of ammonium sulfate. Acetaminophen acylation wastewater belongs to the category of organophosphorus pesticide wastewater. Due to its complex and diverse production processes, complex composition, and difficult-to-degrade pollutants, it is characterized by high COD and high ammonia nitrogen levels, exhibiting strong toxicity and posing a significant risk to the environment and human health.

[0003] Currently, the main method for treating acetyl methylamine phosphorylation wastewater is to add concentrated sulfuric acid to the wastewater, then extract and recover the acetic acid, and finally concentrate and evaporate the raffinate to recover ammonium sulfate. This process is lengthy, costly, and the recovered acetic acid has an odor. Summary of the Invention

[0004] This application provides a method for recycling and utilizing acetaminophen phosphorylation wastewater, which solves the problems of long process, high cost and odor of the recovered acetic acid in traditional acetaminophen phosphorylation wastewater treatment methods.

[0005] To solve the above-mentioned technical problems, one technical solution adopted in this application is: to provide a method for recycling and utilizing acetaminophen phosphorylation wastewater, the method comprising:

[0006] The acetylaminophosphorylation wastewater is evaporated and concentrated. The generated steam is cooled and separated into layers. The lower layer is an oil phase containing dichloromethane, and the upper layer is an aqueous phase. The aqueous phase is distilled to obtain methanol. The concentrated acetylaminophosphorylation wastewater is the first mother liquor.

[0007] The first mother liquor is cooled to allow ammonium sulfate to crystallize out. The ammonium sulfate crystals are then separated by filtration, and the filtrate is an ammonium acetate solution.

[0008] An alkaline solution is added to the filtrate to form a reaction solution. The reaction solution is heated to generate ammonia gas. The ammonia gas is recycled for the acetylation neutralization process in the acetophos production process, or the ammonia gas is absorbed by water to produce ammonia water, which is then recycled for the neutralization of the reaction solution.

[0009] The deaminated reaction solution was cooled and crystallized, and sodium acetate trihydrate crystals and a second mother liquor were obtained by filtration.

[0010] The second mother liquor is decolorized and then recycled into the acetamiprid acylation wastewater as back-extraction water for acetamiprid.

[0011] Optionally, the evaporation method used for evaporating and concentrating the acetylmethamine phosphorylated wastewater is multi-effect evaporation, with an evaporation temperature of 50°C to 130°C and an evaporation pressure of -0.95 atm to 3 atm.

[0012] Optionally, the cooling temperature for cooling the first mother liquor so that ammonium sulfate crystallizes from the first mother liquor is between 0°C and 60°C.

[0013] Optionally, the mass fraction of the alkaline solution is 30% to 100%.

[0014] Optionally, the cooling temperature for cooling and crystallizing the deaminated reaction solution is between 0°C and 60°C.

[0015] Optionally, during the process of obtaining methanol from the aqueous phase through distillation, the top temperature of the column is 64°C and the bottom temperature is 105°C.

[0016] Optionally, the heating temperature for heating the reaction solution to generate ammonia gas is in the range of 100°C to 130°C.

[0017] The beneficial effects of this application are as follows: by concentrating the acetaminophen phosphorylation wastewater to recover the organic matter methanol and dichloromethane in the wastewater, the concentrated first mother liquor is cooled and crystallized to separate ammonium sulfate, and then an alkaline solution is added to react with the first mother liquor. The ammonia gas generated by heating the reaction solution can be recycled for the acetylation neutralization process or absorbed with water to produce ammonia water. The deammoniated reaction solution is cooled and crystallized to obtain sodium acetate trihydrate and a second mother liquor. The second mother liquor is decolorized and recycled for the back-extraction water of acetaminophen. This method not only recovers the solvents methanol and dichloromethane in the acetaminophen phosphorylation wastewater, but also recovers ammonia and recycles it in the neutralization process of the acetylation reaction. Moreover, the quality of the sodium acetate trihydrate product obtained by crystallization can meet the national standards. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Wherein:

[0019] Figure 1This is a flowchart of a method for recycling and utilizing acetylmethamine phosphorylation wastewater provided in an embodiment of this application. Detailed Implementation

[0020] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0021] It should be noted that if the embodiments of this application involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0022] Furthermore, if the embodiments of this application involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, features defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed in this application.

[0023] like Figure 1 As shown, this application provides a method for recycling and utilizing acetylmethamine phosphorylation wastewater. In a specific embodiment:

[0024] 200g of acetamiprid phosphorylation wastewater was added to a 500ml three-necked flask. The flask was then placed in a magnetic stirring heating mantle, forming a simple distillation apparatus. The acetamiprid phosphorylation wastewater was heated to 110℃ under an evaporation pressure of 1 atm for evaporation, concentration, and dehydration until the acetamiprid phosphorylation wastewater was concentrated to about 67%. During the evaporation and concentration process, steam was generated. The steam was collected and condensed by a condenser to form a condensate. The condensate consists of two layers: a lower oil phase containing dichloromethane, which can be recycled for the extraction of acetamiprid; and an upper aqueous solution. The upper aqueous solution was distilled to obtain methanol at the top of the column, while the bottom liquid, after cooling, can be recycled for the back-extraction of acetamiprid.

[0025] The above-mentioned process involves evaporating and concentrating the acetamiprid phosphorylation wastewater to obtain a first mother liquor. This mother liquor is then cooled to 10°C, causing ammonium sulfate crystals to precipitate. The mother liquor is then filtered to separate the ammonium sulfate crystals, which have a mass fraction of 99%. The resulting filtrate is an ammonium acetate solution. 33.3g of a 60% sodium hydroxide solution is added to the filtrate to obtain a reaction solution. The sodium hydroxide solution converts ammonium acetate into sodium acetate and ammonia. The reaction solution is heated to 100°C, causing ammonia gas to evaporate. The evaporated ammonia gas is absorbed with water to obtain a 20% ammonia solution. Furthermore, the ammonia gas obtained by heating the reaction solution can be recycled for the acetylation neutralization process in the acetamiprid production process.

[0026] The reaction solution after the ammonia gas is evaporated is cooled to 10°C, causing sodium acetate trihydrate to crystallize out. The sodium acetate trihydrate crystals and the second mother liquor are obtained by filtration. The mass fraction of the sodium acetate trihydrate crystals is 59.6%. After drying and dehydration, anhydrous sodium acetate crystals are obtained. The second mother liquor is decolorized by ozone or hydrogen peroxide. The decolorized second mother liquor is recycled back to the evaporation and concentration process of acetamiprid phosphate wastewater and used as back-extraction water for acetamiprid.

[0027] The above are all preferred embodiments of this application and are not intended to limit the scope of protection of this application. For those skilled in the art, various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of this application. Therefore, all equivalent changes made to the structure, shape, and principle of this application should be covered within the scope of protection of this application.

Claims

1. A method for recycling and resource utilization of acephate acetylation wastewater, characterized in that, include: The acetaminophen phosphorylation wastewater is evaporated and concentrated. The generated steam is cooled and separated into layers. The lower layer is an oil phase containing dichloromethane, and the upper layer is an aqueous phase. The aqueous phase is distilled to obtain methanol. The concentrated acetaminophen phosphorylation wastewater is the first mother liquor. The oil phase containing dichloromethane is recycled for the extraction process of acetaminophen. The first mother liquor is cooled to allow ammonium sulfate to crystallize out. The ammonium sulfate crystals are then separated by filtration, and the filtrate is an ammonium acetate solution. An alkaline solution is added to the filtrate to form a reaction solution. The reaction solution is heated to generate ammonia gas, which is then recycled for the acetylation neutralization process in the acetophos production process. The deaminated reaction solution was cooled and crystallized, and sodium acetate trihydrate crystals and a second mother liquor were obtained by filtration. The second mother liquor is decolorized and then recycled into the acetamiprid acylation wastewater as back-extraction water for acetamiprid.

2. The method for recycling and resource utilization of acephate acetylation wastewater according to claim 1, characterized in that, The evaporation method used to concentrate the acetylmethamine phosphorylated wastewater is multi-effect evaporation, with an evaporation temperature of 50℃ to 130℃ and an evaporation pressure of -0.95atm to 3atm.

3. The method for recycling and resource utilization of acephate acetylation wastewater according to claim 1, characterized in that, The cooling temperature for cooling the first mother liquor so that ammonium sulfate crystallizes out of the first mother liquor is between 0°C and 60°C.

4. The method for recycling and resource utilization of acephate acetylation wastewater according to claim 1, characterized in that, The cooling temperature for cooling and crystallizing the deaminated reaction solution is from 0°C to 60°C.

5. The method for recycling and resource utilization of acephate acetylation wastewater according to claim 1, characterized in that, During the process of obtaining methanol from the aqueous phase through distillation, the top temperature of the column is 64°C and the bottom temperature is 105°C.

6. The method for recycling and resource utilization of acetylmethamine phosphorylation wastewater according to claim 1, characterized in that, The heating temperature range for heating the reaction solution to generate ammonia is 100°C to 130°C.

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