Hydrolyzing agent for treating wastewater from difluoropyrazole production and preparation method and application thereof

Abstract

The invention discloses a hydrolyzing agent for treating wastewater from the production of difluoropyrazole acid, and a preparation method and application thereof. The hydrolyzing agent is prepared by reacting a solid mineral and a liquid activator, wherein the solid mineral is a mixture of calcium ferrite, calcium aluminate, silicon dioxide and manganese dioxide, and the liquid activator is a zinc chloride solution, a cupric chloride solution or a magnesium sulfate solution. The preparation method comprises mixing the solid mineral with the liquid activator and stirring, impregnating, calcining and activating, to obtain the hydrolyzing agent. The hydrolyzing agent of the invention has the advantages of reducing the hydrolysis temperature, shortening the hydrolysis time, improving the hydrolysis effect, etc. The preparation method has the advantages of simple operation, easy availability of raw materials, green environmental protection, etc., and is suitable for continuous large-scale batch production. The hydrolyzing agent of the invention can be applied to the treatment of wastewater from the production of difluoropyrazole acid, has a significant effect on reducing the concentration of COD, total nitrogen and fluoride ions in the wastewater, can significantly reduce the chromaticity of the wastewater, greatly improves the biodegradability, and has a good application prospect.

Description

Technical Field

[0001] The invention belongs to the technical field of pesticide wastewater treatment, and specifically relates to a hydrolyzing agent for treating difluoropyrazole acid production wastewater, a preparation method thereof, and application thereof in treating difluoropyrazole acid production wastewater. Background Art

[0002] Difluoropyrazole acid, full name 3-difluoromethyl-1-methyl-1H-pyrazole-4-carboxylic acid, is a key intermediate of pyrazole amide fungicides such as fluopyram, fluopyram, fluopyram hydroxylamide, pyraclostrobin, bixafen and benzovintriazole. Fluorinated pyrazole amide fungicides are a type of fungicide that has developed rapidly in recent years and have become a new hotspot in fungicide research and development. Therefore, difluoropyrazole acid has a large market demand.

[0003] The wastewater produced by diflupyrazole acid is highly toxic, highly chromatic, and difficult to degrade. Its COD is as high as 80,000 to 100,000 mg / L, and its total nitrogen is 3,000 to 4,200 mg / L. In order to make the wastewater meet the standards for entering the biochemical system, the concentration of COD and other nitrogen-containing and fluorine-containing pollutants in the wastewater must be greatly reduced, thereby improving the biodegradability of the wastewater.

[0004] At present, there are few studies on the treatment of wastewater from the production of difluoropyrazole acid. The applicant found through repeated experiments that high-temperature alkaline hydrolysis cannot significantly reduce the COD of wastewater, and the color of the wastewater after treatment is darker; during the high-temperature Fenton oxidation reaction, a thick foam layer is generated in the system, which is difficult to use in large-scale wastewater treatment; after distilling the wastewater, the color of the wastewater is significantly improved, but the COD of the mother liquor after distillation is as high as hundreds of thousands of ppm, the odor is heavy, and subsequent treatment is difficult. Summary of the invention

[0005] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a hydrolyzing agent for treating difluoropyrazole acid production wastewater, which can improve the hydrolysis efficiency of difluoropyrazole acid production wastewater, reduce the hydrolysis time and temperature, and have a decolorizing effect on the production wastewater. Accordingly, a preparation method and application of the hydrolyzing agent for treating difluoropyrazole acid production wastewater are also provided.

[0006] In order to solve the above technical problems, the present invention adopts the following technical solutions.

[0007] A hydrolyzing agent for treating difluoropyrazole acid production wastewater is prepared by reacting a solid mineral and a liquid activator, wherein the solid mineral is a mixture of calcium ferrite, calcium aluminate, silicon dioxide and manganese dioxide, and the liquid activator is a zinc chloride solution, a cupric chloride solution or a magnesium sulfate solution.

[0008] The above-mentioned hydrolyzing agent for treating difluoropyrazole acid production wastewater, preferably, the mass volume ratio of the solid mineral to the liquid activator is 13g~18g:7mL, the mass ratio of the calcium ferrite, calcium aluminate, silicon dioxide, and manganese dioxide is 6~8:4~6:2~3:1, and the mass concentration of the liquid activator is 0.1mol / L~0.6mol / L.

[0009] As a general technical concept, the present invention also provides a method for preparing the above-mentioned hydrolyzing agent for treating difluoropyrazole acid production wastewater, comprising the following steps:

[0010] S1. Mixing and stirring the solid mineral and the liquid activator, and impregnating;

[0011] S2, calcining and activating after impregnation to obtain a hydrolyzing agent for treating wastewater from the production of difluoropyrazole acid.

[0012] In the above-mentioned method for preparing a hydrolyzing agent for treating difluoropyrazole acid production wastewater, preferably, in step S2, the calcination activation temperature is 400° C. to 800° C., and the calcination activation time is 2 h to 5 h.

[0013] The above-mentioned method for preparing a hydrolyzing agent for treating difluoropyrazole acid production wastewater, preferably, in step S1, the stirring speed is 120r / min~180r / min, the stirring temperature is 20℃~30℃, the stirring time is 15min~30min, the immersion temperature is 20℃~30℃, and the immersion time is 1h~2h.

[0014] As a general technical concept, the present invention also provides the above-mentioned hydrolyzing agent for treating difluoropyrazole acid production wastewater or the use of the hydrolyzing agent prepared by the above-mentioned preparation method in treating difluoropyrazole acid production wastewater.

[0015] The above application preferably comprises the following steps:

[0016] (1) adjusting the pH of difluoropyrazole acid production wastewater to 10-11, adding the hydrolyzing agent, stirring and mixing, first heating to 80° C.-100° C. and keeping the temperature, then cooling and filtering;

[0017] (2) The pH value of the wastewater filtered in step (1) is adjusted to 9-10, and aeration is performed to complete the pretreatment of the difluoropyrazole production wastewater.

[0018] In the above application, preferably, in step (1), a sodium hydroxide solution is used to adjust the pH value of the difluoropyrazole acid production wastewater, the amount of the sodium hydroxide solution added is 4% to 6% of the mass of the difluoropyrazole acid production wastewater, and the mass fraction of NaOH in the sodium hydroxide solution is 30% to 36%; the amount of the hydrolyzing agent added is 3% to 6% of the mass of the difluoropyrazole acid production wastewater; the insulation time is 2h to 3h, and the cooling is to cool the difluoropyrazole acid production wastewater to 20°C to 30°C.

[0019] In the above application, preferably, in step (2), sodium hydroxide solution is used to adjust the pH value of the filtered wastewater, the amount of the sodium hydroxide solution added is 0.5% to 2% of the mass of the filtered wastewater, and the mass fraction of NaOH in the sodium hydroxide solution is 30% to 36%; the aeration temperature is 20°C to 30°C, the aeration time is 2h to 3h, and the aeration volume is 0.5m 3 / h~0.8m 3 / h.

[0020] Compared with the prior art, the advantages of the present invention are:

[0021] (1) The present invention provides a hydrolyzing agent for treating difluoropyrazole acid production wastewater, which is essentially a hydrolyzing agent prepared by a solid mineral mixture and a liquid activator. In the present invention, after the solid mineral is mixed with the liquid activator, the effective active substances of the solid mineral powder are directly leached, so that the number of holes on the solid surface increases, the specific surface area increases, the pore size distribution becomes more uniform, and the pore structure becomes richer. At the same time, the effective ingredients in the hydrolyzing agent can adsorb small molecular organic matter, inorganic anions, etc. in the system after hydrolysis, and effectively reduce the concentration of COD and inorganic matter in the wastewater. The difluoropyrazole acid production wastewater is brown-red under acidic conditions and brown-black under neutral to alkaline conditions. The chromaticity is relatively high, which is not conducive to the biochemical and discharge of the wastewater in the later stage. The addition of the hydrolyzing agent of the present invention can effectively reduce the chromaticity of the wastewater, and the treated wastewater is light yellow.

[0022] (2) The hydrolyzing agent for treating difluoropyrazole acid production wastewater of the present invention uses calcium ferrite, calcium aluminate, silicon dioxide and manganese dioxide as mineral raw materials, and zinc chloride solution, cupric chloride solution or magnesium sulfate solution as liquid activator. Practice shows that the metal oxide generated by the liquid activator after calcination and activation generates polymers with substances such as Fe, Al, Si, Mn, Ca in the mineral raw materials, which can effectively destroy the chemical bonds of organic pollutants in the wastewater and disassemble highly toxic long-chain organic matter into non-toxic or low-toxic short-chain small molecular organic matter. When the hydrolyzing agent of the present invention is used in treating difluoropyrazole acid production wastewater, the hydrolysis temperature can be reduced from 180-200°C to 80-100°C, the hydrolysis time can be reduced from 5 hours to 2-3 hours, and the hydrolysis reaction pH can be reduced from 13-14 to 10-11, which significantly improves the hydrolysis efficiency and greatly improves the biodegradability of the wastewater.

[0023] (3) The preparation method of the present invention is simple to operate, the raw materials are readily available, and it is green and environmentally friendly, and is suitable for continuous large-scale batch production.

[0024] (4) The hydrolyzing agent of the present invention can be applied to the treatment (specifically pretreatment) of difluoropyrazole acid production wastewater, adopts hydrolysis-aeration process synergy, is easy to operate, is carried out under normal pressure, and does not produce secondary pollution during the treatment process. Adding the hydrolyzing agent of the present invention during the hydrolysis process can effectively improve the hydrolysis efficiency, and the reaction conditions are also milder, reducing the material requirements for the equipment and increasing the service life of the reaction equipment. Practice shows that the hydrolyzing agent of the present invention has a good treatment effect on difluoropyrazole acid production wastewater, and the biodegradability of the wastewater is significantly improved, the fluoride ion removal rate is above 85%, the COD removal rate is above 88%, the total nitrogen removal rate is above 84%, and the wastewater biodegradability is above 0.45. DETAILED DESCRIPTION

[0025] The present invention is further described below in conjunction with specific preferred embodiments, but the protection scope of the present invention is not limited thereby. The materials and instruments used in the following embodiments are all commercially available, and the obtained data are the average values ​​of more than three tests.

[0026] In the following examples, the treatment object is difluoropyrazole acid production wastewater, and the water quality is: pH value is 1, fluoride ion concentration is 525 mg / L, COD concentration is 91600 mg / L, total nitrogen concentration is 3570 mg / L, and wastewater biodegradability B / C=0.04.

[0027] Example 1

[0028] The invention discloses a hydrolyzing agent for treating wastewater from difluoropyrazole acid production. The hydrolyzing agent is prepared by the joint reaction of a solid mineral and a liquid activator.

[0029] In this embodiment, the solid mineral is a mixture of calcium ferrite, calcium aluminate, silicon dioxide and manganese dioxide, and the mass ratio of calcium ferrite, calcium aluminate, silicon dioxide and manganese dioxide is 6:4:2:1.

[0030] In this embodiment, the liquid activator is a zinc chloride solution with a mass concentration of 0.1 mol / L.

[0031] In this embodiment, the mass volume ratio of the solid mineral to the liquid activator is 13 g:7 mL.

[0032] A method for preparing a hydrolyzing agent for treating difluoropyrazole acid production wastewater according to the present embodiment comprises the following steps:

[0033] S1. Weigh 6 g of calcium ferrite, 4 g of calcium aluminate, 2 g of silicon dioxide and 1 g of manganese dioxide, mix with 7 mL of 0.1 mol / L zinc chloride solution, stir at 20°C for 15 min, rotate at 120 r / min, and soak at 20°C for 1 h after stirring;

[0034] S2. After impregnation, the mixture was activated at 400° C. for 2 h. After activation, 13.20 g of a hydrolyzing agent for treating wastewater from the production of difluoropyrazole acid was obtained.

[0035] An application of the hydrolyzing agent for treating difluoropyrazole acid production wastewater of this embodiment comprises the following steps:

[0036] (1) Take 100g of difluoropyrazole acid production wastewater, add 4g of 30% sodium hydroxide solution, adjust the wastewater to pH 10, add 3g of the above hydrolyzing agent, stir and mix evenly, heat to 80°C, keep warm for 2h, cool to 20°C, and filter;

[0037] (2) Take 100 g of the filtered wastewater, add 0.5 g of 30% sodium hydroxide solution, adjust the pH of the wastewater to 9, and start aeration. The aeration temperature is 20 °C, the time is 2 h, and the aeration volume is 0.5 m 3 / h, after aeration, the pretreatment of difluoropyrazole acid production wastewater is completed.

[0038] According to the test, after the hydrolysis-aeration pretreatment of the present invention, the fluoride ion concentration in the effluent of the above-mentioned difluoropyrazole acid production wastewater was 77 mg / L, and the fluoride ion removal rate was 85%; the COD concentration was 8601 mg / L, and the COD removal rate was 91%; the total nitrogen concentration was 576 mg / L, and the total nitrogen removal rate was 84%, and the wastewater B / C was increased to 0.45.

[0039] Example 2

[0040] The invention discloses a hydrolyzing agent for treating wastewater from difluoropyrazole acid production. The hydrolyzing agent is prepared by the joint reaction of a solid mineral and a liquid activator.

[0041] In this embodiment, the solid mineral is a mixture of calcium ferrite, calcium aluminate, silicon dioxide and manganese dioxide, and the mass ratio of calcium ferrite, calcium aluminate, silicon dioxide and manganese dioxide is 8:6:3:1.

[0042] In this embodiment, the liquid activator is a cupric chloride solution with a mass concentration of 0.6 mol / L.

[0043] In this embodiment, the mass volume ratio of the solid mineral to the liquid activator is 18 g:7 mL.

[0044] A method for preparing a hydrolyzing agent for treating difluoropyrazole acid production wastewater according to the present embodiment comprises the following steps:

[0045] S1. Weigh 8 g of calcium ferrite, 6 g of calcium aluminate, 3 g of silicon dioxide and 1 g of manganese dioxide, mix with 7 mL of 0.6 mol / L copper chloride solution, stir at 30 ° C for 30 min, speed 180 r / min, and soak at 30 ° C for 2 h after stirring;

[0046] S2. After impregnation, the mixture was activated at 800°C for 5 hours, and 18.57 g of hydrolyzing agent for difluoropyrazole acid production wastewater was obtained after activation.

[0047] An application of the hydrolyzing agent for treating difluoropyrazole acid production wastewater of this embodiment comprises the following steps:

[0048] (1) Take 100g of difluoropyrazole acid production wastewater, add 6g of 36% sodium hydroxide solution, adjust the pH of the wastewater to 11, add 6g of the above hydrolyzing agent, stir and mix evenly, heat to 100°C, keep warm for 3h, cool to 30°C, and filter;

[0049] (2) Take 100 g of the filtered wastewater, add 2 g of 36% sodium hydroxide solution, adjust the pH of the wastewater to 10, and start aeration. The aeration temperature is 30 °C, the time is 3 h, and the aeration volume is 0.8 m 3 / h, after aeration, the pretreatment of difluoropyrazole acid production wastewater is completed.

[0050] According to the test, after the hydrolysis-aeration pretreatment of the present invention, the fluoride ion concentration in the effluent of the above-mentioned difluoropyrazole acid production wastewater was 52 mg / L, and the fluoride ion removal rate was 90%; the COD concentration was 4836 mg / L, and the COD removal rate was 95%; the total nitrogen concentration was 417 mg / L, and the total nitrogen removal rate was 88%, and the wastewater B / C was increased to 0.57.

[0051] Example 3

[0052] The invention discloses a hydrolyzing agent for treating wastewater from difluoropyrazole acid production. The hydrolyzing agent is prepared by the joint reaction of a solid mineral and a liquid activator.

[0053] In this embodiment, the solid mineral is a mixture of calcium ferrite, calcium aluminate, silicon dioxide and manganese dioxide, and the mass ratio of calcium ferrite, calcium aluminate, silicon dioxide and manganese dioxide is 7:5:2.5:1.

[0054] In this embodiment, the liquid activator is a magnesium sulfate solution with a mass concentration of 0.4 mol / L.

[0055] In this embodiment, the mass volume ratio of the solid mineral to the liquid activator is 15.5 g:7 mL.

[0056] A method for preparing a hydrolyzing agent for difluoropyrazole acid production wastewater according to the above embodiment comprises the following steps:

[0057] S1. Weigh 7 g of calcium ferrite, 5 g of calcium aluminate, 2.5 g of silicon dioxide and 1 g of manganese dioxide, mix with 7 mL of 0.4 mol / L magnesium sulfate solution, stir at 25 ° C for 20 min, speed 150 r / min, and then immerse at 30 ° C for 1.5 h;

[0058] S2. After impregnation, the mixture was activated at 600°C for 4 hours, and 15.83 g of hydrolyzing agent for difluoropyrazole acid production wastewater was obtained after activation.

[0059] An application of the hydrolyzing agent for treating difluoropyrazole acid production wastewater of this embodiment comprises the following steps:

[0060] (1) Take 100 g of difluoropyrazole acid production wastewater, add 5 g of 33% sodium hydroxide solution, adjust the pH of the wastewater to 10.6, add 4.5 g of the above hydrolyzing agent, stir and mix evenly, heat to 90° C., keep warm for 2.5 h, cool to 25° C., and filter;

[0061] (2) Take 100 g of the filtered wastewater, add 1 g of 33% sodium hydroxide solution, adjust the pH of the wastewater to 9.5, and start aeration. The aeration temperature is 25 °C, the time is 2.5 h, and the aeration volume is 0.7 m 3 / h, after aeration, the pretreatment of difluoropyrazole acid production wastewater is completed.

[0062] According to the test, after the hydrolysis-aeration pretreatment of the present invention, the fluoride ion concentration in the effluent of the above-mentioned difluoropyrazole acid production wastewater was 63 mg / L, and the fluoride ion removal rate was 88%; the COD concentration was 6240 mg / L, and the COD removal rate was 93%; the total nitrogen concentration was 495 mg / L, and the total nitrogen removal rate was 86%, and the wastewater B / C was increased to 0.51.

[0063] Comparative Example 1

[0064] A method for pretreating difluoropyrazole acid production wastewater is basically the same as Example 2, except that: in step (1), no hydrolyzing agent for treating difluoropyrazole acid production wastewater is added.

[0065] According to the test, after the hydrolysis-aeration pretreatment of the present invention, the fluoride ion concentration in the effluent of the above-mentioned difluoropyrazole acid production wastewater was 497 mg / L, and the fluoride ion removal rate was 5%; the COD concentration was 45360 mg / L, and the COD removal rate was 50%; the total nitrogen concentration was 1916 mg / L, and the total nitrogen removal rate was 46%, and the wastewater B / C was increased to 0.12.

[0066] From the above content, it can be seen that the hydrolysis-aeration pretreatment of the present invention, due to the addition of the hydrolyzing agent prepared by the present invention during the hydrolysis process, makes the fluoride ions, COD, and total nitrogen in the wastewater removed more thoroughly, and the hydrolysis effect is significantly improved. Practice shows that the hydrolyzing agent used for the treatment of difluoropyrazole acid production wastewater of the present invention has a good treatment effect on difluoropyrazole acid production wastewater, the method is simple to operate, the COD degradation efficiency is high, the biodegradability of the wastewater is significantly improved, the fluoride ion removal rate is greater than 85%, the COD removal rate is greater than 88%, the total nitrogen removal rate is greater than 86%, and the wastewater biodegradability is higher than 0.45.

[0067] The above is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as above in the preferred embodiment, it is not used to limit the present invention. Any technician familiar with the art can make many possible changes and modifications to the technical solution of the present invention by using the methods and technical contents disclosed above without departing from the spirit and technical solution of the present invention, or modify it into an equivalent embodiment of equivalent changes. Therefore, any simple modification, equivalent replacement, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention, still fall within the scope of protection of the technical solution of the present invention.

Claims

1. A hydrolyzing agent for treating difluoropyrazole acid production wastewater, characterized in that: The hydrolyzing agent is prepared by mixing a solid mineral and a liquid activator and calcining and activating them. The solid mineral is a mixture of calcium ferrite, calcium aluminate, silicon dioxide and manganese dioxide. The liquid activator is a zinc chloride solution, a cupric chloride solution or a magnesium sulfate solution. The calcining and activating temperature is 400° C. to 800° C. The mass volume ratio of the solid mineral to the liquid activator is 13g-18g:7mL, the mass ratio of the calcium ferrite, calcium aluminate, silicon dioxide and manganese dioxide is 6-8:4-6:2-3:1, and the mass concentration of the liquid activator is 0.1mol / L-0.6mol / L.

2. A method for preparing a hydrolyzing agent for treating difluoropyrazole acid production wastewater as claimed in claim 1, characterized in that: The following steps are involved: S1. Mixing and stirring the solid mineral and the liquid activator, and impregnating; S2, calcining and activating after impregnation, wherein the calcining and activation temperature is 400° C. to 800° C., and the calcining and activation time is 2 h to 5 h, to obtain a hydrolyzing agent for treating wastewater from the production of difluoropyrazole acid.

3. The method for preparing a hydrolyzing agent for treating difluoropyrazole acid production wastewater according to claim 2, characterized in that: In step S1, the stirring speed is 120r / min~180r / min, the stirring temperature is 20℃~30℃, the stirring time is 15min~30min, the immersion temperature is 20℃~30℃, and the immersion time is 1h~2h.

4. Use of the hydrolyzing agent for treating difluoropyrazole acid production wastewater as claimed in claim 1 or the hydrolyzing agent prepared by the preparation method as claimed in claim 2 or 3 in treating difluoropyrazole acid production wastewater.

5. The use according to claim 4, characterized in that: The following steps are involved: (1) adjusting the pH of difluoropyrazole acid production wastewater to 10-11, adding the hydrolyzing agent, stirring and mixing, first heating to 80° C.-100° C. and keeping the temperature, then cooling and filtering; (2) The pH value of the wastewater filtered in step (1) is adjusted to 9-10, and aeration is performed to complete the pretreatment of the difluoropyrazole production wastewater.

6. The use according to claim 5, characterized in that: In step (1), a sodium hydroxide solution is used to adjust the pH value of the difluoropyrazole acid production wastewater, the amount of the sodium hydroxide solution added is 4% to 6% of the mass of the difluoropyrazole acid production wastewater, and the mass fraction of NaOH in the sodium hydroxide solution is 30% to 36%; the amount of the hydrolyzing agent added is 3% to 6% of the mass of the difluoropyrazole acid production wastewater; the insulation time is 2h to 3h, and the cooling is to cool the difluoropyrazole acid production wastewater to 20°C to 30°C.

7. The use according to claim 5 or 6, characterized in that: In step (2), a sodium hydroxide solution is used to adjust the pH value of the filtered wastewater, the amount of the sodium hydroxide solution added is 0.5% to 2% of the mass of the filtered wastewater, and the mass fraction of NaOH in the sodium hydroxide solution is 30% to 36%; the aeration temperature is 20°C to 30°C, the aeration time is 2h to 3h, and the aeration volume is 0.5m 3 / h~0.8m 3 / h.