Comprehensive recovery treatment method for wastewater in preparation process of 7-ANCA

Abstract

The invention relates to a comprehensive recovery and treatment method for wastewater in the preparation process of 7-ANCA. The method comprises the following steps: (1) recovering methanol; (2) recycling tricalcium phosphate; (3) recovering triethylamine; and (4) recovering methanesulfonic acid and hydrochloric acid. The method disclosed by the invention is simple in route, low in cost and easy for industrial operation, and high-purity tricalcium phosphate is prepared from phosphate radicals in the wastewater through a precipitation method; performing temperature control and phase splitting through alkali replacement, and recovering triethylamine through dehydration and rectification; sodium ions in dissolution are removed through resin exchange, methanesulfonic acid and hydrochloric acid are separated through distillation, comprehensive recycling of components in wastewater is achieved, and the recycled triethylamine, saline water and hydrochloric acid can be used for recycling of the process. According to the method, the sewage treatment pressure can be effectively reduced, the environmental pollution is reduced, auxiliary material recycling is realized, and the raw material cost is reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of pharmaceutical chemical industry and relates to a comprehensive recovery and treatment method of wastewater in the preparation process of 7-ANCA. Background Art

[0002] Since their birth, cephalosporin antibiotics have been in a leading position in the field of antibiotics due to their strong antibacterial ability and few side effects, with a market share of more than 60%. Cephalosporin antibiotics are mainly obtained by introducing different groups at the 7-amino group, 3-C group and 4-carboxyl group of key mother nuclei such as 7-ANCA and 7-ADCA, 7-ACA, GCLE, etc.

[0003] 7-ANCA (7-amino-3-anoxane-3-cephalosporin-4-carboxylic acid) is the core intermediate for the synthesis of the third-generation cephalosporins cefuroxime and ceftibuten, and is also the core raw material for the new generation of antibiotics ceftaroline. Currently, the preparation process of 7-ANCA mainly has two directions:

[0004] (1) The cephalosporin intermediate 7-ACA is used as a raw material and is prepared by deesterification at the 3-position and further oxidation to remove the hydroxymethyl group. However, the raw materials of this process route are expensive, the dehydroxymethylation yield is low, and it is limited to the laboratory research level. The reaction process is as follows:

[0005]

[0006] (2) Penicillin G is used as a raw material for ring expansion and transformation. Penicillin G is prepared by esterification, sulfonation, ring opening, oxidation, hydroxyl protection, bromination, and deprotection agent rearrangement cyclization to prepare 3-hydroxycephalosporin. The double bond of the cephalosporin ring is reduced by sodium borohydride to obtain HCA (3-hydroxy-7β-phenylacetamide-3-no-3-cephem ring-2-carboxylic acid diphenylmethyl ester). HCA is esterified with methanesulfonyl chloride catalyzed by triethylamine, and the ester is eliminated by triethylamine. At the same time, the double bond of the cephalosporin ring is reduced to obtain PNCD (3-hydrogen-7β-phenylacetamide-3-no-3-cephem-2-carboxylic acid diphenylmethyl ester). PNCD is decarboxylated and amino protected to obtain 7-ANCA. The reaction flow is as follows:

[0007]

[0008]

[0009] Although the process route of penicillin G as raw material is long, it has the advantages of simple process, high yield, and cheap raw material price. It is currently a common process route for the industrial production of 7-ANCA in China. However, this route produces a lot of waste liquid. In the process of preparing PNCD from HCA, the hydroxyl groups at the 2nd and 3rd positions are esterified with mesyl chloride by triethylamine to form mesylate, and then the ester elimination reaction is catalyzed by triethylamine in an alkaline environment to eliminate the mesylate at the 3rd position, and at the same time, the double bond of the cephalosporin ring is reduced to obtain PNCD. After the reaction, phosphoric acid is used to neutralize the excess triethylamine, and water and organic solvent are added to the reaction solution for phase separation. The product is extracted from the organic phase for the next step of the reaction. The wastewater generated by the phase separation is currently discharged into sewage. The wastewater generally contains 15% to 18% triethylamine, 16% to 18% phosphate, 3% to 4% methanesulfonic acid, 18% to 20% methanol, and the rest is sodium chloride, water, trace amounts of HCA and PNCD, in weight percentage.

[0010] The above wastewater is directly discharged to sewage treatment, which puts great pressure on sewage treatment and also causes pollution of water and soil environment; and the triethylamine in the wastewater is expensive, and phosphate also has important application value in various fields, such as tricalcium phosphate can be used in food industry, feed industry, agriculture and pharmaceutical industry, which is harmless to human body. Methanesulfonate is also widely used in the fields of food, medicine, chemical industry, optics, agriculture, etc., and industrial sodium chloride also has the value of recycling and repeated use. Triethylamine and methanol can be used for PNCD production and recycling. Therefore, the direct sewage treatment of this wastewater not only increases the cost of sewage treatment, pollutes the environment, but also causes a great waste of resources. Therefore, it is necessary to extract the components in this wastewater, which can not only reduce pollution and reduce wastewater costs, but also save resources and create value. Summary of the invention

[0011] Therefore, the object of the present invention is to provide a comprehensive recovery and treatment method for wastewater in the preparation process of 7-ANCA. The method has a simple route, low cost, and is easy to industrialize. High-purity tricalcium phosphate is prepared by precipitation method using phosphate in wastewater; temperature separation is carried out by alkali replacement, and triethylamine is recovered by dehydration and distillation; sodium ions in the solution are removed by resin exchange, and methanesulfonic acid and hydrochloric acid are separated by distillation, so as to realize comprehensive recovery and utilization of components in wastewater, and the recovered triethylamine, brine and hydrochloric acid can be used for recycling in the process.

[0012] According to the present invention, the comprehensive recovery and treatment method of wastewater in the preparation process of 7-ANCA provided by the present invention comprises:

[0013] (1) Recovery of methanol

[0014] The pH of the wastewater is adjusted to 5.5-6.8 using phosphoric acid or hydrochloric acid, and then subjected to reduced pressure distillation to obtain crude methanol and wastewater from which methanol has been removed; the crude methanol is dehydrated with calcium oxide and then distilled to obtain purified methanol;

[0015] (2) Recovery of tricalcium phosphate

[0016] Adding a calcium source to the above-mentioned methanol removal wastewater at room temperature, stirring the reaction, precipitating a white tricalcium phosphate precipitate, filtering and collecting the filtrate, and washing the tricalcium phosphate filter cake with a water:alcohol solution in a volume ratio of 1:2 to 1:8, rinsing with purified water, and drying to obtain purified tricalcium phosphate;

[0017] (3) Recovery of triethylamine

[0018] Adding sodium hydroxide or potassium hydroxide to the filtrate collected in step (2) to adjust the pH to 9-14, controlling the feed liquid temperature at 25°C-40°C to perform static phase separation, obtaining crude triethylamine in the upper layer and brine in the lower layer; adding a dehydrating agent to the crude triethylamine to dehydrate it, and then performing rectification to obtain purified triethylamine;

[0019] (4) Recovery of methanesulfonic acid and hydrochloric acid

[0020] The brine obtained in the above step (3) is adjusted to neutrality with hydrochloric acid, and passed through a cation exchange resin to obtain a strongly acidic flow-through liquid, wherein the sodium ions in the brine are exchanged for hydrogen ions; the strongly acidic flow-through liquid is distilled, wherein the hydrogen chloride tail gas is subjected to a two-stage absorption treatment, wherein the first stage is absorbed by water and the second stage is absorbed by alkaline water, and the bottom of the kettle is cooled to obtain solid methanesulfonic acid.

[0021] Beneficial Effects

[0022] The invention provides a comprehensive recovery and treatment method for wastewater in the preparation process of 7-ANCA. The method has a simple route, low cost and is easy to be industrially operated. High-purity tricalcium phosphate is prepared by precipitation method using phosphate in the wastewater; temperature separation is performed by alkali replacement and dehydration and rectification is performed to recover triethylamine; sodium ions in the solution are removed by resin exchange, and methanesulfonic acid and hydrochloric acid are separated by distillation, so as to realize comprehensive recovery and utilization of components in the wastewater, and the recovered triethylamine, brine and hydrochloric acid can be used for recycling in the process.

[0023] This method can effectively reduce the pressure of sewage treatment, reduce environmental pollution, realize the recycling of auxiliary materials, and reduce the cost of raw materials. DETAILED DESCRIPTION

[0024] Hereinafter, the comprehensive recovery and treatment method of wastewater in the preparation process of 7-ANCA of the present invention will be described in detail to facilitate the understanding of the present invention. However, the embodiments of the present invention may be modified in various different forms, and the scope of the present invention is not limited to the embodiments to be described below. The embodiments of the present invention are provided to make the present disclosure clear and complete, so as to fully explain the present invention to those of ordinary skill in the art.

[0025] As described above, in the preparation process of 7-ANCA, in the process of preparing PNCD from HCA, the hydroxyl groups at positions 2 and 3 are esterified with mesyl chloride by triethylamine to form mesylate, and then the mesylate at position 3 is eliminated by an ester elimination reaction catalyzed by an excess of triethylamine in an alkaline environment, and the double bond of the cephalexin ring is reduced to obtain PNCD. After the reaction, phosphoric acid is used to neutralize the excess triethylamine, and water and an organic solvent are added to the reaction solution for phase separation. The product is extracted from the organic phase for the next reaction, and the wastewater generated by the phase separation is currently discharged into sewage, which generally contains 15% to 18% triethylamine, 16% to 18% phosphate, 3% to 4% methanesulfonic acid, 18% to 20% methanol, and the rest is sodium chloride, water, and residual trace amounts of HCA and PNCD, in terms of weight percentage.

[0026] In the step (1) of recovering methanol, the pH of the wastewater is adjusted to 5.5-6.8 using phosphoric acid or hydrochloric acid, and then the crude methanol and the de-methanolized wastewater are obtained by vacuum distillation; the crude methanol is dehydrated with calcium oxide and then distilled to obtain purified methanol.

[0027] Specifically, phosphoric acid or hydrochloric acid is used to adjust the pH of the wastewater to 5.5-6.8, preferably 6.0-6.5, for example, 85wt% phosphoric acid or 32wt% hydrochloric acid is used to adjust the pH of the wastewater to 5.5-6.8, preferably 6.0-6.5, and then reduced pressure distillation is carried out under a vacuum of -0.085 to -0.090MPa and a temperature of 25°C to 36°C to obtain crude methanol and wastewater from which methanol is removed. The crude methanol is dehydrated with calcium oxide and then distilled to obtain purified methanol.

[0028] In the step (2) of recovering tricalcium phosphate, a calcium source is added to the above-mentioned wastewater from methanol removal at room temperature, the reaction is stirred to precipitate a white tricalcium phosphate precipitate, the filtrate is collected by filtration, and the tricalcium phosphate filter cake is washed with a solution of water:alcohol in a volume ratio of 1:2 to 1:8, rinsed with purified water, and dried to obtain purified tricalcium phosphate.

[0029] Wherein, the calcium source can be one or more selected from calcium carbonate, calcium oxide, calcium hydroxide and calcium chloride, and is preferably calcium oxide, and the amount of calcium source can be calculated according to the molar ratio of calcium ions to phosphate ions in the wastewater of about 3:2; the water:alcohol solution is in a volume ratio of 1:2 to 1:8, wherein the alcohol can be methanol or ethanol; the drying is carried out at a temperature of 90°C to 110°C and a vacuum of -0.085 to -0.090MPa.

[0030] In the step (3) of recovering triethylamine, sodium hydroxide or potassium hydroxide is added to the filtrate collected in the step (2) to adjust the pH to 9-14, and the feed liquid temperature is controlled at 25° C.-40° C. to perform static phase separation, so that crude triethylamine is obtained in the upper layer and brine is obtained in the lower layer; a dehydrating agent is added to the crude triethylamine to dehydrate it, and then distilled to obtain purified triethylamine.

[0031] Specifically, solid sodium hydroxide or potassium hydroxide is added to the filtrate collected in step (2) to adjust the pH to 9-14, preferably 12-13, and then the feed liquid temperature is controlled at 25°C-40°C, preferably 28°C-32°C for static phase separation, and crude triethylamine is obtained in the upper layer and brine is obtained in the lower layer; the crude triethylamine has a water content of about 1%-5%, and a dehydrating agent such as molecular sieve, sodium hydroxide, sodium chloride, etc. can be added to the crude triethylamine for dehydration, and then distillation is performed to obtain purified triethylamine with a water content of less than 0.05% and a purity of more than 99.9%.

[0032] In the step (4) of recovering methanesulfonic acid and hydrochloric acid, the brine obtained in the above step (3) is adjusted to neutrality with hydrochloric acid, and is passed through a cation exchange resin to obtain a strongly acidic flow-through liquid, wherein the sodium ions in the brine are exchanged for hydrogen ions; the strongly acidic flow-through liquid is distilled, wherein the hydrogen chloride tail gas is subjected to a two-stage absorption treatment, wherein the first stage is water absorption and the second stage is alkaline water absorption, and the bottom of the kettle is cooled to obtain solid methanesulfonic acid.

[0033] The cation exchange resin is a strongly acidic cation exchange resin, such as the model LXT-140 cation exchange resin of Gaoling Lanxiao Technology New Materials Co., Ltd., which is activated to a hydrogen form by soaking in hydrochloric acid before use. The brine obtained in the above step (3) is adjusted to neutrality with hydrochloric acid, and passed through the cation exchange resin to obtain a strongly acidic flow-through liquid, whose pH value is less than 1.

[0034] Then, the strongly acidic flow-through liquid is transferred to a distillation kettle for atmospheric distillation, the kettle temperature is slowly raised to 120° C., water is recovered at the top of the tower, and no fraction is generated at the top of the tower. The temperature in the distillation kettle is lowered to obtain light yellow methanesulfonic acid with a content of up to 99.5%. The hydrogen chloride gas in the distillation tail gas is subjected to secondary absorption using water and sodium hydroxide liquid alkali. The hydrochloric acid obtained by absorbing the hydrogen chloride gas with water has a concentration of 5% and can be used for activation and regeneration of cationic resin. The hydrogen chloride gas is absorbed by sodium hydroxide alkaline water to reach a neutral pH and can be used as brine for phase separation in the 7-ANCA preparation process.

[0035] The comprehensive recovery and treatment method of wastewater in the preparation process of 7-ANCA of the present invention is further described in detail below through examples, and the protection scope of the present invention is not limited to the following examples, which are listed only for illustrative purposes and do not limit the present invention in any way.

[0036] In the preparation process of 7-ANCA, the wastewater obtained by phase separation in the preparation of PNCD has a pH of 7.5, a triethylamine content of 16%, a phosphate content of 18%, a methanesulfonic acid content of 3.6%, a methanol content of 18%, and the rest is sodium chloride, water, trace amounts of HCA and PNCD.

[0037] Example 1

[0038] (1) Recovery of methanol

[0039] Take 2500g of the above waste water, add 85% phosphoric acid to adjust the pH to 6.5, use a rotary evaporator, vacuum -0.089MPa, temperature 36 ° C, vacuum distillation to recover 501g of crude methanol (water content of about 10%, methanol content of 90%, methanol purity of 99.6%), and collect 1980g of waste water after desolventization, and distill and volatilize and lose 19g of water. The crude methanol is dehydrated by adding calcium oxide and then distilled to obtain 431g of finished methanol (water content of 0.05%), with a purity of 99.6%, and a methanol recovery rate of up to 95.7%.

[0040] (2) Recovery of tricalcium phosphate

[0041] Slowly add 398 g of solid calcium oxide to 1980 g of the waste water after desolventization at room temperature, stir and react for 10 minutes to precipitate white tricalcium phosphate, and collect 1585 g of the filtrate by filtration;

[0042] The tricalcium phosphate filter cake was washed with 300 ml of a solution of water:methanol in a volume ratio of 1:5, and then rinsed with 600 ml of purified water. The solid was dried in a vacuum drying oven at 100°C and vacuum -0.085 MPa to constant weight to obtain 721 g of tricalcium phosphate. The tricalcium phosphate content was 99.3% and the phosphate recovery rate was 98.2%.

[0043] (3) Recovery of triethylamine

[0044] Solid sodium hydroxide was added to 1585 g of the filtrate collected in step (2) to adjust the pH to 13, and the feed liquid temperature was controlled at 28° C. to allow static phase separation, wherein 401 g of crude triethylamine (water content: 1.5%) was present in the upper layer and 1190 g of brine was present in the lower layer; 20 g of molecular sieve was added to the crude triethylamine for dehydration, and then distillation was performed to obtain 365 g of finished triethylamine with a water content of 0.02%, a purity of 99.96%, and a triethylamine yield of 91.25%.

[0045] (4) Recovery of methanesulfonic acid and hydrochloric acid

[0046] 1190 g of the brine obtained in step (3) above was adjusted to neutrality with 32 wt % hydrochloric acid, and passed through a cation exchange resin column (LXT-140 cation exchange resin produced by Gaoling Lanxiao Technology New Materials Co., Ltd., with a loading of 600 ml and a height-to-diameter ratio of 3:1) at a flow rate of 2 BV / h to obtain a strongly acidic flow-through liquid (pH 0.3), wherein the sodium ions in the brine were exchanged for hydrogen ions, and 1 BV of water was used for top washing, and the collected top washing liquid was incorporated into the strongly acidic flow-through liquid, totaling 1812 g; then, the strongly acidic flow-through liquid 181 2g is transferred to a distillation kettle for atmospheric distillation, the kettle temperature is slowly raised to 120°C, water is recovered at the top of the tower, and the distillation is stopped until no fraction is produced at the top of the tower. The temperature in the distillation kettle is lowered to obtain 86g of light yellow methanesulfonic acid with a yield of 95.5%; the hydrogen chloride gas in the distillation tail gas is subjected to secondary absorption by water and sodium hydroxide liquid alkali, the hydrochloric acid obtained by absorbing the hydrogen chloride gas with water has a concentration of 5%, which can be used for activation and regeneration of cationic resin, and the hydrogen chloride gas is absorbed by sodium hydroxide alkaline water to reach a neutral pH, which can be used as brine for phase separation in the preparation process of 7-ANCA.

[0047] Example 2

[0048] (1) Recovery of methanol

[0049] Take 2500g of the above waste water, add 32% hydrochloric acid to adjust the pH to 6.0, use a rotary evaporator, vacuum -0.089MPa, temperature 36 ° C, vacuum distillation to recover 521g of crude methanol, and collect 1962g of waste water after desolventization, and lose 17g of water by distillation and volatilization. The crude methanol is dehydrated by adding calcium oxide and then distilled to obtain 419g of finished methanol (water content 0.02%), with a purity of 99.9% and a methanol recovery rate of 93.1%.

[0050] (2) Recovery of tricalcium phosphate

[0051] Slowly add 526 g of solid calcium hydroxide to 1962 g of the waste water after desolventization at room temperature, stir and react for 10 minutes to precipitate white tricalcium phosphate precipitate, and collect 1637 g of the filtrate by filtration;

[0052] The tricalcium phosphate filter cake was washed with 300 ml of a solution of water:methanol in a volume ratio of 1:8, and then rinsed with 600 ml of purified water. The solid was dried in a vacuum drying oven at 100°C and vacuum -0.085 MPa to constant weight to obtain 713 g of tricalcium phosphate. The tricalcium phosphate content was 99.3% and the phosphate recovery rate was 97.1%.

[0053] (3) Recovery of triethylamine

[0054] Solid sodium hydroxide was added to 1637 g of the filtrate collected in step (2) to adjust the pH to 13, and the feed liquid temperature was controlled at 28° C. to allow static phase separation, wherein 350 g of crude triethylamine (water content: 2.4%) was present in the upper layer and 1287 g of brine was present in the lower layer; 20 g of molecular sieve was added to the crude triethylamine for dehydration, and then distillation was performed to obtain 337 g of finished triethylamine with a water content of 0.05%, a purity of 99.92%, and a triethylamine yield of 84.25%.

[0055] (4) Recovery of methanesulfonic acid and hydrochloric acid

[0056] 1287g of the brine obtained in the above step (3) was adjusted to neutrality with 32wt% hydrochloric acid, and passed through a cation exchange resin column (same as in Example 1) at a flow rate of 2BV / h to obtain a strongly acidic flow-through liquid (pH 0.6), wherein the sodium ions in the brine were exchanged for hydrogen ions, and 1BV of water was used for top washing, and the collected top washing liquid was merged into the strongly acidic flow-through liquid, totaling 1890g; then, the strongly acidic flow-through liquid was transferred to a distillation kettle for atmospheric distillation, and the kettle temperature was slowly raised to 120°C, and water was recovered at the top of the tower. When no fraction was produced at the top of the tower, the distillation was stopped, and the temperature in the distillation kettle was lowered to obtain 85g of light yellow methanesulfonic acid, with a yield of 94.4%; the hydrogen chloride gas in the distillation tail gas was subjected to secondary absorption using water and sodium hydroxide liquid alkali.

[0057] Example 3

[0058] (1) Recovery of methanol

[0059] Take 2500g of the above waste water, add 85% phosphoric acid dropwise to adjust the pH to 6.5, use a rotary evaporator, vacuum -0.089MPa, temperature 30°C, vacuum distillation to recover 452g of crude methanol (water content of about 8%, methanol content of 92%, methanol purity of 99.7%), and collect 2037g of waste water after desolventization, and distillation and volatilization loss of 11g of water. The crude methanol is dehydrated by adding calcium oxide and then distilled to obtain 414g of finished methanol (water content of 0.03%), with a purity of 99.9%, and a methanol recovery rate of up to 92%.

[0060] (2) Recovery of tricalcium phosphate

[0061] Slowly add 788 g of solid calcium chloride to 2037 g of the waste water after desolventization at room temperature, stir and react for 10 minutes to precipitate white tricalcium phosphate precipitate, and collect 1864 g of the filtrate by filtration;

[0062] The tricalcium phosphate filter cake was washed with 300 ml of a solution of water:methanol in a volume ratio of 1:8, and then rinsed with 600 ml of purified water. The solid was dried in a vacuum drying oven at 100°C and vacuum -0.085 MPa to constant weight to obtain 725 g of tricalcium phosphate. The tricalcium phosphate content was 99.6% and the phosphate recovery rate was 98.8%.

[0063] (3) Recovery of triethylamine

[0064] Solid sodium hydroxide was added to 1864 g of the filtrate collected in step (2) to adjust the pH to 12, and the feed liquid temperature was controlled at 30° C. to allow static phase separation, resulting in 431 g of crude triethylamine (water content: 1.7%) in the upper layer and 1433 g of brine in the lower layer; 20 g of molecular sieve was added to the crude triethylamine for dehydration, followed by rectification to obtain 359 g of finished triethylamine with a water content of 0.02%, a purity of 99.97%, and a triethylamine yield of 89.75%.

[0065] (4) Recovery of methanesulfonic acid and hydrochloric acid

[0066] 1433g of the brine obtained in the above step (3) was adjusted to neutrality with 32wt% hydrochloric acid, and passed through a cation exchange resin column (same as in Example 1) at a flow rate of 2BV / h to obtain a strongly acidic flow-through liquid (pH 0.5), wherein the sodium ions in the brine were exchanged for hydrogen ions, and 1BV of water was used for top washing, and the collected top washing liquid was merged into the strongly acidic flow-through liquid, totaling 2036g; then, the strongly acidic flow-through liquid was transferred to a distillation kettle for atmospheric distillation, and the kettle temperature was slowly raised to 120°C, and water was recovered at the top of the tower. When no fraction was produced at the top of the tower, the distillation was stopped, and the temperature in the distillation kettle was lowered to obtain 81g of light yellow methanesulfonic acid, with a yield of 90%; the hydrogen chloride gas in the distillation tail gas was secondary absorbed using water and sodium hydroxide liquid alkali.

Claims

1. A comprehensive method for recycling wastewater in the preparation process of 7-ANCA, comprising: (1) Recovery of methanol The pH of the wastewater is adjusted to 5.5-6.8 using phosphoric acid or hydrochloric acid, and then subjected to reduced pressure distillation to obtain crude methanol and wastewater from which methanol has been removed; the crude methanol is dehydrated with calcium oxide and then distilled to obtain purified methanol; (2) Recovery of tricalcium phosphate Adding a calcium source to the above-mentioned methanol removal wastewater at room temperature, stirring the reaction, precipitating a white tricalcium phosphate precipitate, filtering and collecting the filtrate, and washing the tricalcium phosphate filter cake with a water:alcohol solution in a volume ratio of 1:2 to 1:8, rinsing with purified water, and drying to obtain purified tricalcium phosphate; (3) Recovery of triethylamine Adding sodium hydroxide or potassium hydroxide to the filtrate collected in step (2) to adjust the pH to 9-14, controlling the feed liquid temperature at 25°C-40°C to perform static phase separation, obtaining crude triethylamine in the upper layer and brine in the lower layer; adding a dehydrating agent to the crude triethylamine to dehydrate it, and then performing rectification to obtain purified triethylamine; (4) Recovery of methanesulfonic acid and hydrochloric acid The brine obtained in the above step (3) is adjusted to neutrality with hydrochloric acid, and passed through a cation exchange resin to obtain a strongly acidic flow-through liquid, wherein the sodium ions in the brine are exchanged for hydrogen ions; the strongly acidic flow-through liquid is distilled, wherein the hydrogen chloride tail gas is subjected to a two-stage absorption treatment, wherein the first stage is absorbed by water and the second stage is absorbed by alkaline water, and the bottom of the kettle is cooled to obtain solid methanesulfonic acid.

2. The comprehensive recovery and treatment method for wastewater in the preparation process of 7-ANCA according to claim 1, characterized in that: The wastewater is produced in the process of preparing PNCD, i.e., 3-hydrogen-7β-phenylacetamide-3-no-3-cephem-2-carboxylic acid diphenylmethyl ester from HCA, i.e., 3-hydroxy-7β-phenylacetamide-3-no-3-cephem-2-carboxylic acid diphenylmethyl ester. The wastewater contains 15% to 18% of triethylamine, 16% to 18% of phosphate radical, 3% to 4% of methanesulfonic acid, 18% to 20% of methanol, and the rest is sodium chloride, water, and trace amounts of HCA and PNCD, calculated by weight percentage.

3. The comprehensive recovery and treatment method for wastewater in the preparation process of 7-ANCA according to claim 1, characterized in that In the step (1) of recovering methanol, the pH value of the waste water is adjusted to 5.5-6.8 using phosphoric acid or hydrochloric acid, and then reduced pressure distillation is performed at a vacuum of -0.085-0.090 MPa and a temperature of 25°C-36°C to obtain crude methanol and waste water from which methanol is removed. The crude methanol is dehydrated with calcium oxide and then distilled to obtain purified methanol.

4. The comprehensive recovery and treatment method for wastewater in the preparation process of 7-ANCA according to claim 3, characterized in that In the step (1) of recovering methanol, the pH value of the wastewater is adjusted to 6.0-6.5 using 85wt% phosphoric acid or 32wt% hydrochloric acid, and then reduced pressure distillation is performed at a vacuum of -0.085-0.090MPa and a temperature of 25°C-36°C to obtain crude methanol and wastewater from which methanol is removed. The crude methanol is dehydrated with calcium oxide and then distilled to obtain purified methanol.

5. The comprehensive recovery and treatment method for wastewater in the preparation process of 7-ANCA according to claim 1, characterized in that In the step (2) of recovering tricalcium phosphate, the calcium source is one or more selected from calcium carbonate, calcium oxide, calcium hydroxide and calcium chloride.

6. The comprehensive recovery and treatment method for wastewater in the preparation process of 7-ANCA according to claim 5, characterized in that The step (2) recovers the tricalcium phosphate, wherein the water:alcohol solution has a volume ratio of 1:2 to 1:8, wherein the alcohol is methanol or ethanol; and the drying is performed at a temperature of 90° C. to 110° C. and a vacuum of -0.085 to -0.090 MPa.

7. The comprehensive recovery and treatment method for wastewater in the preparation process of 7-ANCA according to claim 1, characterized in that In the step (3) of recovering triethylamine, solid sodium hydroxide or potassium hydroxide is added to the filtrate collected in the step (2) to adjust the pH to 12-13, and then the feed liquid temperature is controlled at 28°C-32°C for static phase separation, and crude triethylamine is obtained on the upper layer, and brine is obtained on the lower layer; the crude triethylamine has a water content of 1%-5%, and molecular sieves, sodium hydroxide or sodium chloride dehydrating agents are added to the crude triethylamine for dehydration, and then distillation is performed to obtain purified triethylamine, with a water content of less than 0.05% and a purity of more than 99.9%.

8. The comprehensive wastewater recovery and treatment method in the preparation process of 7-ANCA according to claim 1, characterized in that In the step (4) of recovering methanesulfonic acid and hydrochloric acid, the cation exchange resin is a strongly acidic cation exchange resin, which is activated to a hydrogen form by soaking in hydrochloric acid before use.

9. The comprehensive recovery and treatment method for wastewater in the preparation process of 7-ANCA according to claim 1, characterized in that In the step (4), methanesulfonic acid and hydrochloric acid are recovered, the strongly acidic flow-through liquid is transferred to a distillation kettle for atmospheric distillation, the kettle temperature is slowly raised to 120° C., water is recovered at the top of the tower, and when no fraction is produced at the top of the tower, the temperature in the distillation kettle is lowered to obtain light yellow methanesulfonic acid, and the hydrogen chloride gas in the distillation tail gas is subjected to secondary absorption using water and sodium hydroxide liquid alkali.

10. The comprehensive wastewater recovery and treatment method in the preparation process of 7-ANCA according to claim 1, characterized in that In the step (1), in recovering methanol, the pH value of the wastewater is adjusted to 5.5 to 6.8 using phosphoric acid or hydrochloric acid, and then vacuum distillation is performed at a vacuum of -0.085 to -0.090 MPa and a temperature of 25°C to 36°C to obtain crude methanol and wastewater from which methanol is removed. The crude methanol is dehydrated with calcium oxide and then distilled to obtain purified methanol; In the step (2) of recovering tricalcium phosphate, the calcium source is one or more selected from calcium carbonate, calcium oxide, calcium hydroxide and calcium chloride, the water:alcohol solution is in a volume ratio of 1:2 to 1:8, wherein the alcohol is methanol or ethanol; the drying is carried out at a temperature of 90° C. to 110° C. and a vacuum of -0.085 to -0.090 MPa; In the step (3) of recovering triethylamine, solid sodium hydroxide or potassium hydroxide is added to the filtrate collected in the step (2) to adjust the pH to 12-13, and then the feed liquid temperature is controlled at 28° C.-32° C. to perform static phase separation, and crude triethylamine is obtained on the upper layer, and brine is obtained on the lower layer; the crude triethylamine has a water content of 1%-5%, and molecular sieves, sodium hydroxide or sodium chloride dehydrating agents are added to the crude triethylamine for dehydration, and then distillation is performed to obtain purified triethylamine, with a water content of less than 0.05% and a purity of more than 99.9%; In the step (4) of recovering methanesulfonic acid and hydrochloric acid, the cation exchange resin is a strongly acidic cation exchange resin, which is activated to a hydrogen form by soaking in hydrochloric acid before use; the strongly acidic flow-through liquid is transferred to a distillation kettle for atmospheric distillation, the kettle temperature is slowly raised to 120° C., water is recovered at the top of the tower until no fraction is generated at the top of the tower, the temperature in the distillation kettle is lowered to obtain light yellow methanesulfonic acid, and the hydrogen chloride gas in the distillation tail gas is subjected to secondary absorption using water and sodium hydroxide liquid alkali.

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