A method for extracting and recovering glyphosate and glyphosate from glyphosate wastewater

Abstract

The present invention discloses a method for recovering glyphosate from glyphosate mother liquor. The main steps include: extracting glyphosate and glyphosate directly from the glyphosate mother liquor using solvent extraction, then stripping the glyphosate and glyphosate using a mixed salt solution and a loaded organic phase, and recycling the loaded organic phase. This patent proposes using solvent extraction to extract the amphoteric organic substances glyphosate and glyphosate, achieving extraction rates of up to 95% for glyphosate and 95% for glyphosate, respectively. The organic phase is recycled, achieving economic and environmental benefits. This patent aims to address challenges faced by the glyphosate industry, significantly reduce production costs, and generate significant social and economic benefits.

Description

Technical Field

[0001] The present invention relates to the field of treatment of phosphorus-containing organic wastewater generated in the glyphosate production process, and in particular to a method for green and efficient recycling of glyphosate and glyphosate containing glyphosate, glyphosate-enhanced, diglyphosate and their metabolites (containing phosphino / carboxyl functional groups). Background Art

[0002] The glyphosate production process generates wastewater (i.e., glyphosate wastewater) containing greater than 0.8% glyphosate, approximately 2% glyphosate-enhanced and its metabolites, and other organic phosphorus. The mother liquor has complex components, a salinity of approximately 15%, and a chemical oxygen demand (COD) greater than 20,000, making it extremely difficult to treat. Direct discharge can cause environmental pollution and even impact the entire ecosystem. Therefore, the effective recovery and utilization of glyphosate and glyphosate-enhanced in glyphosate wastewater can not only effectively avoid environmental pollution but also bring huge economic benefits.

[0003] Glyphosate, chemically known as N-(phosphomethyl)glycine, is a broad-spectrum organophosphorus pesticide with high herbicidal activity. Its mechanism of action is to inhibit the synthesis of aromatic amino acids and shikimic acid, thereby inhibiting photosynthetic phosphorylation and the activity of adenosine triphosphatase (ATPase), thereby hindering plant growth and metabolism. Glyphosate, chemically known as N,N-bis(phosphonomethyl)glycine, can complex metal cations such as calcium and iron to form a dense protective film, forming a coordination or chelation effect to effectively reduce the corrosion rate of metal substances. Glyphosate can also inhibit the activity of sugarcane acid invertase, thereby increasing the sweetness of sugarcane.

[0004] Currently, there are few reports on the selective recovery of glyphosate from glyphosate mother liquor. Patent 110229186A provides a method for recovering glyphosate and glyphosate from glyphosate mother liquor. The method involves separating crude sodium chloride by quenching, followed by acidification and vacuum dehydration to obtain an organic mixture of glyphosate and glyphosate. Water is then added to the colloid solidified by a gelling agent to obtain water-soluble glyphosate and colloidally precipitated glyphosate. This method is expected to achieve a 25% yield of glyphosate and glyphosate, but the process is lengthy and generates new acidification wastewater and colloidal wastewater. Patent 102127112B discloses a method for separating glyphosate solids from concentrated glyphosate mother liquor. This involves adding calcium chloride as a precipitant to obtain a filter cake, dissolving it with acid, adjusting the pH, and recovering the glyphosate using an ion exchange resin. A disadvantage of this method is that the filter cake is complex, containing calcium salts of organic phosphine compounds, requiring further separation using an ion exchange resin. Patent 113336790A adds a soluble solid salt to a glyphosate mother liquor, reacts and separates the solid and liquid, then adds an alkaline solution to the precipitate, separates and dries it, and produces glyphosate. Patent 112745349B adds a soluble solid salt to a glyphosate mother liquor, then directly adds an inorganic acid to adjust the pH, and allows the mixture to stand for crystallization and separation to produce the glyphosate product. This simplifies the process for selective separation and recovery of glyphosate. However, the disadvantage is that the glyphosate product contains calcium ions and other substances, resulting in low purity. Summary of the Invention

[0005] The present invention addresses the deficiencies of existing technologies and provides a method for the green and economical recovery of glyphosate and glyphosate from glyphosate production wastewater. This method utilizes the bipolar nature of the molecular structures of glyphosate and glyphosate to extract and separate glyphosate and glyphosate using an ionic liquid extractant and an organic solvent. The single-stage extraction rate reaches 55% or higher, more preferably 60% or higher, more preferably 65% ​​or higher, more preferably 70% or higher, more preferably 75% or higher, more preferably 80% or higher, more preferably 85% or higher, more preferably 90% or higher, and more preferably 95% or higher. The organic phase loaded with glyphosate and glyphosate is stripped with an alkaline solution to obtain the glyphosate and glyphosate products.

[0006] The specific technical solutions of the present invention are as follows:

[0007] A method for extracting and recovering glyphosate and glyphosate from glyphosate wastewater, the method is as follows:

[0008] (1) Adding an extractant to the glyphosate mother liquor produced during the glyphosate production process;

[0009] (2) stirring the mixed solution formed above, and then allowing it to stand for separation to obtain an organic phase and an aqueous phase;

[0010] (3) The separated extracted organic phase and salt solution are stirred and mixed, and allowed to stand for stratification to obtain a stripping organic phase and a stripping aqueous phase; the organic phase is further used to extract the glyphosate mother liquor;

[0011] (4) The stripping aqueous phase is concentrated to obtain glyphosate and glyphosate products.

[0012] The glyphosate mother solution includes glyphosate, glyphosate-enhanced, glyphosate-bis(glyphosate), glyphosate-methyl, glyphosate-aminomethyl, glyphosate-hydroxymethyl, and glycine, wherein the contents of glyphosate and glyphosate are 0.8-2.0% and 2.0-6.0%, respectively, and the contents of other phosphorus-containing components are 0.8-1.5%.

[0013] The extractant is a mixture of a quaternary ammonium or quaternary phosphonium ion liquid extractant and an organic solvent, and the mass fraction of the extractant is 20%-70%.

[0014] The ionic liquid extractant is selected from any one of trialkylmethylammonium chloride (Aliquat 336), trihexyl(tetradecyl)phosphine chloride (Cyphos IL 101), and trihexyltetradecylphosphonium di(2,4,4-trimethylpentyl)phosphite (Cyphos IL 104).

[0015] The organic solvent is selected from any one of toluene, kerosene and dodecane.

[0016] The volume ratio of the extractant to the glyphosate mother liquor is 1:1-4, the volume ratio of the extracted organic phase to the saline solution is 1:1-4, and the saline solution is selected from a sodium chloride aqueous solution. The extracted organic phase is recycled.

[0017] The stirring speed of step (2) and step (3) is 100-500 r / min, and the stirring time is 5 min-2 h; the standing time for stratification is 10 min-2 h.

[0018] The glyphosate mother liquor contains complex components, all of which are functional groups such as amino, carboxyl, or phosphoric acid, with similar physicochemical properties, making selective recovery and separation challenging. As organic polyphosphates with excellent chelating properties, glyphosate and glyphosate-enhanced can assume various forms depending on the solution pH. Compared to other components, they have more anionic functional groups, enabling synergistic extraction through both positive and negative electron coordination (anion exchange) and chelation. Furthermore, the nitrogen atom's lone electron pair forms a p-π conjugated system with the carbonyl groups C=O and P=O. However, the two phosphate groups and one carboxyl group significantly shield the nitrogen atom, hindering the proton's access to the nitrogen atom and causing significant steric hindrance for glyphosate-enhanced. Taking these factors into account, the extraction and separation of glyphosate-enhanced ions primarily relies on the large number of anionic functional groups to mitigate their steric hindrance. Quaternary ammonium or quaternary phosphonium ionic liquids with alkalinity and weak chelating properties are used as extractants. By exploiting the differences in the complexing abilities of components in the mother liquor with the extractant, highly selective extraction and separation of glyphosate and glyphosate-enhanced ions can be achieved. The chemical reaction equation is shown in (1-2):

[0019] [P + ]Cl - + NPG - = [P + ] NPG - + Cl - (1)

[0020] [N + ]Cl - + NPG - = [N + ] NPG - + Cl - (2)

[0021] The technical solution of the present invention provides a green and economical method for recovering glyphosate and glyphosate from glyphosate production wastewater. This method utilizes the bipolarity of the molecular structures of glyphosate and glyphosate to extract and separate glyphosate and glyphosate using an ionic liquid extractant and an organic solvent, achieving a single-stage extraction rate of approximately 95%. The organic phase loaded with glyphosate and glyphosate is then stripped with a saline solution to obtain the glyphosate and glyphosate products.

[0022] The ionic liquid extractant used in the present invention has a mass fraction of 20% to 70% in the organic phase mixed with the organic solvent. Below a mass fraction of 20%, the extraction rate of glyphosate and glyphosate is low; above a mass fraction of 70%, the extraction rate of glyphosate and glyphosate is not significantly improved.

[0023] The present invention adopts a solvent extraction method to directly extract glyphosate and glyphosate from glyphosate mother liquor, which has a short process.

[0024] The present invention has a high single-stage extraction rate for glyphosate or glyphosate; the single-stage extraction rate reaches 55% and above, more preferably 60% and above, more preferably 65% ​​and above, more preferably 70% and above, more preferably 75% and above, more preferably 80% and above, more preferably 85% and above, more preferably 90% and above, more preferably 95% and above.

[0025] The loaded organic phase of the present invention can be recycled, which is economical and environmentally friendly. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a process flow chart of the present invention. DETAILED DESCRIPTION

[0027] The present invention will be described in detail below with reference to specific embodiments, which have no limiting effect on the present invention.

[0028] The glyphosate mother liquor wastewater in the embodiments of this application has a pH of 9.14 and a total phosphorus content of 106,353 ppm, including 15,287 ppm of glyphosate, 46,012 ppm of glyphosate, 9,854 ppm of other phosphorus components, including glyphosate, methyl glyphosate, aminomethyl phosphonic acid, and hydroxymethyl phosphonic acid. The inorganic phosphorus content is 35,200 ppm. The chemical oxygen demand (COD) is 27,840.

[0029] Example 1

[0030] The method for wastewater resource treatment of the present invention is as follows:

[0031] Prepare 200 mL of Aliquat 336-toluene organic extractant (Aliquat 336 mass fraction 20%) and mix it with 200 mL of glyphosate mother liquor. Stir at 300 r / min for 5 minutes, then let it stand for 20 minutes to separate the layers. Remove the lower aqueous phase and analyze the glyphosate and glyphosate contents. Remove the upper organic phase and mix it with 200 mL of 2 mol / L NaCl solution. Stir at 300 r / min for 5 minutes, then let it stand for 20 minutes to separate the layers. Remove the lower aqueous phase and analyze the glyphosate and glyphosate contents, which were 36810 ppm and 11455 ppm, respectively. No other impurities were detected.

[0032] Example 2

[0033] Prepare 200 mL of an Aliquat 336-toluene organic extract (50% by mass Aliquat 336) and mix it with 200 mL of glyphosate mother liquor. Stir at 300 r / min for 5 minutes, then let it stand for 20 minutes to separate the layers. Remove the lower aqueous phase and analyze its glyphosate and glyphosate contents. Remove the upper organic phase and mix it with 200 mL of a 2 mol / L NaCl solution. Stir at 300 r / min for 5 minutes, then let it stand for 20 minutes to separate the layers. The lower aqueous phase was removed and analyzed, revealing glyphosate and glyphosate contents of 41,415 ppm and 13,755 ppm, respectively. No other impurities were detected.

[0034] Example 3

[0035] Prepare 200 mL of an Aliquat 336-toluene organic extract (70% by mass Aliquat 336) and mix it with 200 mL of glyphosate mother liquor. Stir at 300 r / min for 5 minutes, then let it stand for 20 minutes to separate the layers. Remove the lower aqueous phase and analyze its glyphosate and glyphosate contents. Remove the upper organic phase and mix it with 200 mL of a 2 mol / L NaCl solution. Stir at 300 r / min for 5 minutes, then let it stand for 20 minutes to separate the layers. The lower aqueous phase was removed and analyzed, revealing glyphosate and glyphosate contents of 43,712 ppm and 14,523 ppm, respectively. No other impurities were detected.

[0036] Example 4

[0037] Prepare 200 mL of an Aliquat 336-toluene organic extract (Aliquat 336 at a mass fraction of 15%) and mix it with 200 mL of glyphosate mother liquor. Stir at 300 r / min for 5 minutes, then let it stand for 20 minutes to separate the layers. Remove the lower aqueous phase and analyze its glyphosate and glyphosate contents. Remove the upper organic phase and mix it with 200 mL of a 2 mol / L NaCl solution. Stir at 300 r / min for 5 minutes, then let it stand for 20 minutes to separate the layers. Remove the lower aqueous phase and analyze its glyphosate and glyphosate contents, which were 27610 ppm and 8407 ppm, respectively. No other impurities were detected.

[0038] Example 5

[0039] Prepare 200 mL of an Aliquat 336-toluene organic extract (Aliquat 336 at 80% by mass) and mix it with 200 mL of glyphosate mother liquor. Stir at 300 r / min for 5 minutes, then let it stand for 20 minutes to separate the layers. Remove the lower aqueous phase and analyze its glyphosate and glyphosate contents. Remove the upper organic phase and mix it with 200 mL of a 2 mol / L NaCl solution. Stir at 300 r / min for 5 minutes, then let it stand for 20 minutes to separate the layers. The lower aqueous phase was removed and analyzed for glyphosate and glyphosate contents, revealing glyphosate and glyphosate contents of 44,172 ppm and 14,830 ppm, respectively. No other impurities were detected.

[0040] Example 6

[0041] Prepare 200 mL of Cyphos IL 101-toluene organic extract (Cyphos IL 101, 50% by mass) and mix with 200 mL of glyphosate mother liquor. Stir at 300 r / min for 5 minutes, then let it stand for 20 minutes to separate the layers. Remove the lower aqueous phase and analyze the glyphosate and glyphosate contents. Remove the upper organic phase and mix it with 200 mL of 2 mol / L NaCl solution. Stir at 300 r / min for 5 minutes, then let it stand for 20 minutes to separate the layers. Remove the lower aqueous phase and analyze the glyphosate and glyphosate contents, which were 40,032 ppm and 13,760 ppm, respectively. No other impurities were detected.

[0042] Example 7

[0043] Prepare 200 mL of Cyphos IL 104-toluene organic extract (Cyphos IL 104 mass fraction 50%) and mix it with 200 mL of glyphosate mother liquor. Stir at 300 r / min for 5 minutes, then let it stand for 20 minutes to separate the layers. Remove the lower aqueous phase and analyze the glyphosate and glyphosate contents. Remove the upper organic phase and mix it with 200 mL of 2 mol / L NaCl solution. Stir at 300 r / min for 5 minutes, then let it stand for 20 minutes to separate the layers. Remove the lower aqueous phase and analyze the glyphosate and glyphosate contents, which were 38189 ppm and 14369 ppm, respectively. No other impurities were detected.

Claims

1. A method for extracting and recovering glyphosate and glyphosate from glyphosate wastewater, characterized in that: Here’s how: (1) adding an extractant to the glyphosate mother liquor produced in the glyphosate production process, wherein the extractant is a mixture of a quaternary ammonium or quaternary phosphonium ionic liquid extractant and an organic solvent, wherein the ionic liquid extractant is selected from any one of Aliquat 336, CyphosIL 101, and Cyphos IL 104, and the organic solvent is selected from any one of toluene, kerosene, and dodecane; (2) stirring the mixed solution formed above, and then allowing it to stand for separation to obtain an organic phase and an aqueous phase; (3) stirring and mixing the separated extracted organic phase and a saline solution, wherein the saline solution is selected from a sodium chloride aqueous solution, and allowing the mixture to stand and separate to obtain a stripping organic phase and a stripping aqueous phase; (4) The stripping aqueous phase is concentrated to obtain glyphosate and glyphosate products.

2. The method for extracting and recovering glyphosate and glyphosate from glyphosate wastewater according to claim 1, characterized in that: The glyphosate mother liquor comprises glyphosate, glyphosate-enhanced, glyphosate-bis(glyphosate), methyl glyphosate, aminomethyl phosphonic acid, hydroxymethyl phosphonic acid and glycine, wherein the contents of glyphosate and glyphosate are 0.8-2.0% and 2.0-6.0% respectively, and the contents of other phosphorus-containing components are 0.8-1.5%.

3. The method for extracting and recovering glyphosate and glyphosate from glyphosate wastewater according to claim 1, characterized in that: The mass fraction of the ionic liquid extractant in the extractant is 20%-70%.

4. The method for extracting and recovering glyphosate and glyphosate from glyphosate wastewater according to claim 1, wherein: The volume ratio of the extractant to the glyphosate mother liquor is 1:1-4, and the volume ratio of the extracted organic phase to the salt solution is 1:1-4.

5. The method for extracting and recovering glyphosate and glyphosate from glyphosate wastewater according to claim 1, characterized in that: The stirring speed of step (2) and step (3) is 100-500 r / min, and the stirring time is 5 min-2 h; The standing time for stratification is 10 min-2 h.

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