Method for adsorbing and separating glyphosate and glyphosine

Abstract

The invention discloses a method for adsorbing and separating glyphosate and glyphosine, which adopts a base material loaded with amino-functionalized imidazole ionic liquid as an adsorbent to adsorb and treat wastewater containing glyphosate and glyphosine, the method comprises the following steps: treating an adsorbent adsorbed with glyphosate and glyphosine by using organic acid as an eluent, selectively eluting to obtain glyphosate, and continuously eluting by using inorganic acid / alkali as an eluent to obtain glyphosine; according to the method, the base material loaded with the amino-functionalized imidazole ionic liquid is used as the adsorbent for adsorbing the wastewater containing the glyphosate and the glyphosine, and the adsorbent is high in adsorption speed for a high-concentration glyphosate or glyphosine solution, can be filled in an adsorption column, can be repeatedly utilized and can be used in a relatively wide acid-base range.

Description

Technical Field

[0001] The invention belongs to the technical field of environmental engineering, and in particular relates to a method for adsorption separation of glyphosate and glyphosate. Background Art

[0002] Glyphosate is one of the most widely used herbicides on the market. It has the characteristics of non-selectivity and broad spectrum. Its advantages are high efficiency and low toxicity. In the chemical pesticide industry, high-concentration phosphine-containing wastewater is generated during the preparation of glyphosate powder and glyphosate aqueous solution. Its main components include 1-2% glyphosate, 3-5% glyphosate and about 5% phosphorous acid. These phosphorus-containing compounds will not only cause varying degrees of pollution to water sources, soil, air and ecosystems, but also damage human liver and kidneys. If these phosphides can be separated and recycled, great economic value can be created. For example, the price of glyphosate in the market is US$60,000 per ton, and the price of glyphosate is 100,000 yuan per ton. Therefore, the use of efficient and sustainable methods to remove phosphides in glyphosate mother liquor is of great significance for pollution remediation and resource recovery.

[0003] However, because the properties of phosphides are similar, most of the reports published on the market currently extract them together from the mother liquor, but cannot separate them. For example, patent CN102408441A uses an extraction method to add methanol, acetone and other extractants to the glyphosate mother liquor, and then heats and distills to remove the solvent, thereby achieving the purpose of recovering the phosphides in the mother liquor, but this method does not selectively separate glyphosate and glyphosate.

[0004] How to separate glyphosate and glyphosate while recycling them has become a technical problem that needs to be solved urgently. Summary of the invention

[0005] The present invention aims to provide a method for separating glyphosate and glyphosate by adsorption, which uses a specially prepared adsorbent and a targeted eluent to achieve the adsorption and separation of glyphosate and glyphosate.

[0006] In order to achieve the above purpose, the technical solutions adopted are as follows:

[0007] A method for separating glyphosate and glyphosate by adsorption, comprising the following steps:

[0008] (1) Using a substrate loaded with amino-functionalized imidazole-type ionic liquid as an adsorbent to adsorb and treat wastewater containing glyphosate and glyphosate;

[0009] (2) using an organic acid as an eluent to treat the adsorbent adsorbed with glyphosate and glyphosate, and selectively eluting to obtain glyphosate;

[0010] (3) Using an inorganic acid / base as an eluent, further treating the adsorbent obtained in step 2 to obtain glyphosate.

[0011] According to the above scheme, the wastewater containing glyphosate and glyphosate enhancer is the phosphine-containing wastewater generated during the production and use of glyphosate powder or glyphosate aqueous solution.

[0012] According to the above scheme, the amino-functionalized imidazole ionic liquid in step 1 has the following structural formula:

[0013]

[0014] Wherein, n is an integer between 1 and 8, and X is Cl, Br, or NO3 - 、BF4、NTf2、PF6、[ZnCl4] 2- , [FeCl4] - or [AlCl4] - .

[0015] According to the above scheme, the substrate in step 1 is fibers, particles or films of polymer materials.

[0016] According to the above scheme, the polymer material is preferably one of microcrystalline cellulose and its derivatives, and polystyrene.

[0017] According to the above scheme, step 1 is to load the amino-functionalized imidazole-type ionic liquid onto the substrate surface in the following manner:

[0018] Unsaturated monomers containing epoxy groups are introduced into the surface of the substrate by radiation grafting, and then amino-functionalized imidazole-type ionic liquids are loaded onto the surface of the resin substrate by epoxy ring-opening reaction.

[0019] According to the above scheme, step 1 is to load the amino-functionalized imidazole-type ionic liquid onto the substrate surface in the following manner:

[0020] Benzyl chloride is introduced into the surface of the substrate, and then the amino-functionalized imidazole-type ionic liquid is loaded onto the surface of the resin substrate through a halogenation reaction.

[0021] According to the above scheme, step 1 is to load the amino-functionalized imidazole-type ionic liquid onto the substrate surface in the following manner:

[0022] The amino-functionalized imidazolium ionic liquid containing double bonds is grafted onto the surface of the substrate through a grafting reaction.

[0023] According to the above scheme, the organic acid in step 2 is one of formic acid, acetic acid and propionic acid.

[0024] According to the above scheme, the inorganic acid / base in step 3 is one of hydrochloric acid, nitric acid, sodium hydroxide and potassium hydroxide.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] (1) The present invention uses a substrate loaded with amino-functionalized imidazole-type ionic liquid as an adsorbent to adsorb wastewater containing glyphosate and glyphosate. The adsorbent has a fast adsorption rate for high-concentration glyphosate or glyphosate solution, can be filled in an adsorption column, can be reused, and can be used in a wide acid-base range.

[0027] (2) The present invention uses a substrate loaded with amino-functionalized imidazole-type ionic liquid as an adsorbent and simultaneously introduces secondary / tertiary amine and imidazole groups, as well as hydroxyl groups formed by epoxy ring opening. The coexistence of these multifunctional groups can achieve highly selective adsorption and separation of glyphosate and glyphosate, in which the imidazole ring and -NH participate in the adsorption and separation.

[0028] (3) The present invention uses a substrate loaded with amino-functionalized imidazole-type ionic liquid as an adsorbent to adsorb glyphosate and glyphosate, and then uses organic acid and hydrochloric acid to elute glyphosate and glyphosate step by step, thereby achieving the separation of glyphosate and glyphosate.

[0029] (4) The present invention uses a substrate loaded with amino-functionalized imidazole-type ionic liquid as an adsorbent, which has a simple preparation method, easy control of conditions, low energy consumption, safety and environmental protection, and is more suitable for industrial production.

[0030] (5) The present invention uses a substrate loaded with amino-functionalized imidazole-type ionic liquid as an adsorbent raw material, which is easy to obtain, low-cost, and environmentally friendly, meets the needs of filling and using adsorption columns in industry, and has great industrial application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 : Effect of pH on the adsorption of glyphosate and glyphosate mixed solutions by two adsorbents.

[0032] Figure 2 :The effect diagram of eluting glyphosate and glyphosate with various eluents respectively.

[0033] Figure 3 : Dynamic column experimental effect diagram of dynamic co-adsorption and step-by-step elution of glyphosate and glyphosate mixed solution by adsorbent.

[0034] Figure 4 : Reusability of resins loaded with amino-functionalized imidazolium-type ionic liquids for glyphosate and glyphosate. DETAILED DESCRIPTION

[0035] The following examples further illustrate the technical solution of the present invention, but are not intended to limit the scope of protection of the present invention.

[0036] The specific embodiment provides a resin adsorbent loaded with amino-functionalized imidazole-type ionic liquid:

[0037] (1) 10 g of crystalline cellulose microspheres with a particle size of about 150 μm are vacuum-sealed; electron beam irradiation is performed using an electron accelerator to generate active free radicals that can be used for grafting reactions. Irradiation conditions: irradiation voltage 1 MeV, irradiation dose 30 kGy, dose rate 10 kGy / pass.

[0038] (2) After irradiation, the crystalline cellulose microspheres were immediately put into a deoxygenated emulsion reaction system consisting of glycidyl methacrylate (GMA): Tween 20: water = 30:3:67 wt% for graft polymerization. The graft polymerization reaction was carried out at 50°C and terminated after about 2 hours (the grafting rate of the substrate reached about 250%). The microspheres were washed with water to obtain an adsorbent precursor.

[0039] (3) The above-mentioned adsorbent precursor was mixed with 20 ml of a mixed solution of ethanol and water (ethanol: water 2:1) and 10 g of 1-aminoethyl-3-vinyl imidazole bromide for epoxy ring-opening reaction, and the mixture was shaken at 80° C. for 24 hours. The mixture was taken out, washed with ethanol and water, and dried to obtain an amino-functionalized imidazole-type ionic liquid-supported resin ([AE]Br). The functional group density of the [AE]Br resin was 1.87 mmol / g-ad. The obtained resin was white spherical with a particle size of about 400 μm.

[0040] The specific embodiment also provides another resin adsorbent loaded with amino-functionalized imidazole-type ionic liquid:

[0041] 1-aminopropyl-3-vinylimidazolium bromide was used to replace 1-aminoethyl-3-vinylimidazolium bromide as a reaction monomer to obtain another amino-functionalized imidazole-type ionic liquid-supported resin ([AP]Br), and the functional group density of [AP]Br was 1.78mmol / g-ad. The obtained resin was white spherical with a particle size of about 400um.

[0042] Example 1

[0043] Weigh 0.01 g of the prepared amino-functionalized imidazole ionic liquid-loaded resin, put it into 10 mL of a mixed aqueous solution containing glyphosate and glyphosate at room temperature, adjust the pH range to 1 to 12 with dilute acid and dilute alkali, and conduct a static adsorption test. The above adsorption test was stirred at room temperature, and after 24 hours of adsorption, the concentration of glyphosate was measured with an ultraviolet spectrophotometer, and the concentration was calculated to calculate the resin adsorption amount (Qe).

[0044] The adsorption of phosphides by amino-functionalized imidazolium ionic liquid-supported resins is affected by pH. Figure 1As shown in the figure, it can be seen that these two aminoimidazole ionic liquid adsorbents both show ultra-high adsorption affinity for glyphosate in the binary mixed adsorption of glyphosate and glyphosate, and can adsorb most of the glyphosate in the mixed solution at the concentration of glyphosate and glyphosate. Figure 1 It can be seen that at a pH of 3 to 10, both ionic liquid adsorbents exhibited high adsorption activity, indicating that the adsorbents can be used in a wide acid-base range.

[0045] Example 2

[0046] In order to study how to separate the adsorbed glyphosate and glyphosate, different eluents were used to elute the resin adsorbed with glyphosate and glyphosate. In the elution experiment, 10 mg of amino-functionalized imidazole-type ionic liquid loaded resin was used to adsorb 10 mL of glyphosate and glyphosate at a concentration of 200 mg / L and at the optimal pH for adsorption, and the adsorption time was 24 hours. After the adsorption was completed, 10 mL of various commonly used eluents at a concentration of 1 mol / L were added, placed in a constant temperature oscillator, taken out after 24 hours, and the concentrations of glyphosate and glyphosate in the solution were measured. The results of the elution experiment are shown in the figure. Figure 2 As shown, it can be seen that the organic acid (acetic acid) has different elution effects on glyphosate and glyphosate, and can selectively elute glyphosate.

[0047] Example 3

[0048] Based on the phenomenon that the organic acid acetic acid can selectively elute glyphosate, a binary dynamic column experiment was performed to separate the adsorbed glyphosate and glyphosate by step-by-step elution. First, the adsorbent was loaded into the column, and a binary mixed solution of glyphosate and glyphosate was passed through at a uniform rate. After a certain period of adsorption, the adsorbent now contains glyphosate and glyphosate. At this time, acetic acid was first passed through at a uniform rate to selectively elute glyphosate until no more glyphosate was eluted; then the elution was continued with inorganic acid to elute the glyphosate in the adsorbent. Thus, the effect of separating glyphosate and glyphosate was achieved. The results of the dynamic column experiment are shown in the figure below. Figure 3 shown.

[0049] Example 4

[0050] In order to study the reusability of amino-functionalized imidazole ionic liquid-loaded resin, five adsorption-desorption-adsorption cycles were performed. In each adsorption experiment, 10 mg of amino-functionalized imidazole ionic liquid-loaded resin was used to adsorb 10 mL of glyphosate and glyphosate at a concentration of 200 mg / L and at the optimal pH for adsorption, and the adsorption time was 24 hours. After the adsorption was completed, 10 mL of 1 mol / L HCl was added and placed in a constant temperature oscillator. After 24 hours, it was taken out and the concentrations of glyphosate and glyphosate in the solution were measured. The adsorbent was then washed with deionized water five times to remove the HCl adsorbed on the surface, and the next adsorption experiment was performed. The adsorption experiment results are shown in the figure. Figure 4 As shown, after 5 cycles of adsorption-desorption, the adsorption capacity of the amino-functionalized imidazole ionic liquid-loaded resin for glyphosate and glyphosate still remained above 90%, indicating that they have good reusability.

Claims

1. A method for separating glyphosate and glyphosate by adsorption, characterized in that The following steps are involved: (1) Using a substrate loaded with amino-functionalized imidazole-type ionic liquid as an adsorbent to adsorb and treat wastewater containing glyphosate and glyphosate; (2) using an organic acid as an eluent to treat the adsorbent adsorbed with glyphosate and glyphosate, and selectively eluting to obtain glyphosate; (3) Using an inorganic acid / base as an eluent, further treating the adsorbent obtained in step (2) to obtain glyphosate.

2. The method for separating glyphosate and glyphosate by adsorption as claimed in claim 1, characterized in that The wastewater containing glyphosate and glyphosate enhancer is phosphine-containing wastewater generated during the production and use of glyphosate powder or glyphosate aqueous solution.

3. The method for separating glyphosate and glyphosate by adsorption as claimed in claim 1, characterized in that The amino-functionalized imidazole ionic liquid in step 1 has the following structural formula: Wherein, n is an integer between 1 and 8, and X is Cl, Br, or NO3 - 、BF4、NTf2、PF6、[ZnCl4] 2- , [FeCl4] - or [AlCl4] - .

4. The method for separating glyphosate and glyphosate by adsorption as claimed in claim 1, characterized in that The substrate in step (1) is fibers, particles or films of polymer materials.

5. The method for separating glyphosate and glyphosate by adsorption as claimed in claim 4, characterized in that The polymer material is one of microcrystalline cellulose and its derivatives and polystyrene.

6. The method for separation of glyphosate and glyphosate by adsorption as claimed in claim 1, characterized in that Step (1) The amino-functionalized imidazole ionic liquid is loaded onto the surface of the substrate in the following manner: Unsaturated monomers containing epoxy groups are introduced into the surface of the substrate by radiation grafting, and then amino-functionalized imidazole-type ionic liquids are loaded onto the surface of the resin substrate by epoxy ring-opening reaction.

7. The method for separation of glyphosate and glyphosate by adsorption as claimed in claim 1, characterized in that Step (1) The amino-functionalized imidazole ionic liquid is loaded onto the surface of the substrate in the following manner: Benzyl chloride is introduced into the surface of the substrate, and then the amino-functionalized imidazole-type ionic liquid is loaded onto the surface of the resin substrate through a halogenation reaction.

8. The method for separation of glyphosate and glyphosate by adsorption as claimed in claim 1, characterized in that Step 1: Load the amino-functionalized imidazole ionic liquid onto the substrate surface in the following manner: The amino-functionalized imidazolium ionic liquid containing double bonds is grafted onto the surface of the substrate through a grafting reaction.

9. The method for separation of glyphosate and glyphosate by adsorption as claimed in claim 1, characterized in that The organic acid in step (2) is one of formic acid, acetic acid and propionic acid.

10. The method for separation of glyphosate and glyphosate by adsorption as claimed in claim 1, characterized in that The inorganic acid / base in step (3) is one of hydrochloric acid, nitric acid, sodium hydroxide and potassium hydroxide.

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