A method and system for resourceful treatment of ceftriaxone sodium mother liquor

Abstract

The application discloses a ceftriaxone sodium mother liquor resource treatment method and system, and belongs to the field of mother liquor resource treatment. The ceftriaxone sodium mother liquor resource treatment method comprises the following steps: S1, pretreatment; S2, first-stage membrane separation; S3, second-stage membrane separation; S4, obtaining a high-purity ceftriaxone sodium product; S5, obtaining a byproduct accelerator M; and S6, deep treatment. The system comprises a pretreatment unit, a first-stage membrane separation unit, a second-stage membrane separation unit, a first refining unit, a second refining unit and a deep treatment unit. The application solves the problems of low resource utilization, poor treatment efficiency, high operation cost and secondary pollution in the prior art. The application improves the resource utilization and treatment efficiency, reduces the labor cost and operation cost, and avoids the pollution of the direct discharge of the ceftriaxone sodium mother liquor to the environment.

Description

Technical Field

[0001] This invention relates to the field of mother liquor resource utilization technology, specifically to a method and system for the resource utilization of ceftriaxone sodium mother liquor. Background Technology

[0002] Ceftriaxone sodium, as a third-generation cephalosporin antibiotic, has broad-spectrum antibacterial activity and is widely used in clinical treatment. Its production process generates a large amount of ceftriaxone sodium mother liquor, which has a complex composition. This mother liquor contains not only incompletely reacted ceftriaxone sodium, 7-aminocephalosporanic acid (7-ACA), triazine rings, and other valuable pharmaceutical intermediates, but also high concentrations of salts (such as sodium chloride and sodium sulfate), organic solvents (such as ethanol and acetone), and trace amounts of heavy metal ions and other contaminants.

[0003] Existing technologies for treating ceftriaxone sodium mother liquor mainly include biochemical treatment, advanced oxidation treatment, membrane separation, and evaporation crystallization. However, these methods all have significant drawbacks, making it difficult to achieve efficient resource utilization of the mother liquor: biochemical treatment cannot recover valuable components from the mother liquor, resulting in low resource utilization; while advanced oxidation treatment can degrade organic pollutants in the mother liquor to a certain extent, it also cannot effectively recover pharmaceutical intermediates, only degrading pollutants, which does not conform to the development trend of resource-based treatment; separation methods are difficult to achieve efficient separation and recovery of valuable intermediates, salts, and water; evaporation crystallization is mainly used to recover salts from the mother liquor, but organic pollutants are easily volatilized or decomposed during evaporation, resulting in low purity of the recovered salts, making resource utilization impossible. Existing combined processes, such as "pretreatment + membrane separation + evaporation crystallization," have limited pretreatment methods and cannot effectively remove colloids, suspended solids, and some organic impurities from the mother liquor, leading to easy clogging of subsequent membrane separation components. Therefore, these methods do not meet current needs. To address this, we propose a resource-based treatment method and system for ceftriaxone sodium mother liquor. Summary of the Invention

[0004] The purpose of this invention is to provide a resource-based treatment method and system for ceftriaxone sodium mother liquor. This method achieves precise recovery of solvents, ceftriaxone sodium products, and by-product promoter M from the mother liquor across the entire chain. The treated wastewater meets discharge standards, improving product recovery rate, purity, and resource utilization. It effectively removes impurities from the mother liquor, reduces membrane fouling risk, and improves membrane separation efficiency. The overall process is stable, highly automated, and reduces labor and operating costs. It avoids direct discharge of ceftriaxone sodium mother liquor, thus reducing environmental pollution and achieving pollutant reduction, harmlessness, and resource utilization, solving the problems mentioned in the background section.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a method for the resource utilization of ceftriaxone sodium mother liquor, comprising the following steps: S1: The ceftriaxone sodium mother liquor is introduced into the pretreatment unit and sequentially filtered, pH value adjusted and suspended solids removed to obtain the pretreated solution; S2: The pretreated mother liquor is passed into the primary membrane separation unit and separated using a nanofiltration membrane module to obtain primary permeate and primary concentrate. S3: The obtained primary permeate is passed into the secondary membrane separation unit and separated using a reverse osmosis membrane module to obtain secondary permeate and secondary concentrate; S4: The first-stage concentrate is fed into the first refining unit, where solvents are first recovered by distillation, and then subjected to low-temperature crystallization, centrifugation and recrystallization to obtain high-purity ceftriaxone sodium product. S5: Pass the secondary concentrate into the second refining unit, and sequentially perform distillation to recover residual solvent, ion exchange, vacuum distillation and crystallization to obtain by-product promoter M; S6: The saline waste liquid generated after the second refining unit is passed into the salt recovery unit and subjected to evaporation concentration, cooling crystallization and centrifugal drying in sequence to obtain high-purity industrial-grade salt products. S6: The distilled wastewater generated after the secondary permeate and by-product promoter M are fed into the advanced treatment unit, where it undergoes advanced oxidation, biochemical treatment, and activated carbon adsorption treatment in sequence. The treated wastewater meets the discharge standards.

[0006] Preferably, during the pH adjustment process, the pH of the ceftriaxone sodium mother liquor is adjusted to 2.5-3.5, and a composite coagulant is added. The composite coagulant is composed of polyaluminum chloride, polyacrylamide, and diatomaceous earth in a mass ratio of 5:1:2. The dosage of the composite coagulant is 0.4%-0.6% of the mass of the mother liquor, and the mixture is stirred for 50-70 minutes. High-efficiency sedimentation is carried out in an inclined tube sedimentation tank for 80-120 minutes. Precision filtration is carried out using a precision filter with a filtration accuracy of 0.1-0.2 μm.

[0007] Preferably, the nanofiltration membrane module is selected from nanofiltration membranes with a molecular weight cutoff of 200-300 Da, the operating pressure is controlled at 1.5-2.0 MPa, the temperature is controlled at 25-30℃, and the flow rate is controlled at 50-80 L / h; the primary concentrate is rich in ceftriaxone sodium and solvents, including ethanol, dichloromethane, acetone and triethylamine, and the primary permeate contains some small molecule organic matter, salts and residual solvents.

[0008] Preferably, the reverse osmosis membrane module is a reverse osmosis membrane with a rejection rate of ≥99%, the operating pressure is controlled at 2.5-3.0 MPa, the temperature is controlled at 20-25℃, and the flow rate is controlled at 30-60 L / h; the secondary concentrate is rich in the promoter M precursor, salt and residual solvent, and the secondary permeate is water after preliminary purification.

[0009] Preferably, the reverse osmosis membrane module uses a reverse osmosis membrane with a rejection rate of ≥99%, the operating pressure is controlled at 2.5-3.0 MPa, the temperature is controlled at 20-25℃, and the flow rate is controlled at 30-60 L / h; the secondary permeate is pre-purified water, the ion exchange uses D001 type strong acid cation exchange resin, the adsorption time is 50-70 min, and ammonia water with a mass concentration of 5%-8% is used as the desorbent; the vacuum degree of vacuum distillation is controlled at 0.08-0.09 MPa, and the temperature is controlled at 60-70℃.

[0010] Preferably, the evaporation and concentration are carried out using a triple-effect evaporator, with the evaporation temperature controlled at 95-110℃ and the vacuum degree controlled at 0.06-0.08MPa, evaporating and concentrating to a salt concentration of 30%-40%; cooling and crystallization are carried out at 10-15℃ for 3-5 hours; and centrifugal drying is carried out using hot air drying with the temperature controlled at 80-90℃ for 1.5-2.5 hours.

[0011] Preferably, the advanced oxidation adopts the UV-Fenton advanced oxidation process, with the molar ratio of FeSO4·7H2O to H2O2 being 1:10-12, the Fenton reagent dosage being 0.6%-1.0% of the wastewater mass, and the UV irradiation reaction time being 50-80 min; the biological treatment adopts the A / O process, with the anaerobic tank retention time being 4-6 h, the aerobic tank retention time being 7-10 h, the aeration intensity in the aerobic tank being 1.8-2.5 m³ / (m²·h); and the activated carbon adsorption time being 30-50 min.

[0012] Preferably, in step S2, the primary membrane separation unit is equipped with an intelligent circulating flow control system, which includes a programmable logic controller (PLC), a variable frequency circulating pump, and pressure sensors, flow sensors, and temperature sensors respectively installed at the inlet and outlet of the membrane module and on the permeate side. The PLC is configured to execute a dynamic flux maintenance strategy based on electro-viscous resistance compensation, the specific steps of which include: Continuous real-time monitoring of transmembrane pressure difference in nanofiltration membrane modules Permeation flux and mother liquor temperature ; The PLC calculates the target circulation flow rate at the current moment in real time according to the following calculation model. : in, The preset baseline circulation flow rate; The dynamic viscosity of the mother liquor at the current temperature. Viscosity at reference temperature; For real-time transmembrane pressure difference; This is the preset osmotic pressure compensation value; For real-time permeation flux; This is the inherent resistance constant of the cleaning membrane; and This is an empirical coefficient determined based on the concentration of ceftriaxone sodium in the mother liquor; It represents an exponential function with the natural constant e as its base; The PLC calculates... The frequency of the variable frequency circulating pump is adjusted in real time so that the actual circulating flow rate in the membrane module tracks the target circulating flow rate, thereby ensuring that the shear stress on the membrane surface is sufficient to strip the concentration polarization layer while compensating for fluctuations in fluid viscous resistance caused by temperature changes.

[0013] Preferably, the crystallization process in step S4 employs an adaptive metastable region cruise control strategy based on turbidity change rate feedback. This strategy does not rely on a preset fixed cooling curve, but rather the controller executes the following logical steps: Preset turbidity change rate threshold K and temperature rollback value ; During the cooling process, the turbidity value of the crystallization system was collected at a fixed sampling period, and the first derivative of turbidity with time was calculated. ; Real-time calculation Compare with the threshold K; like If the temperature is less than K, the controller maintains the current cooling rate; like If the temperature is greater than or equal to K, the controller determines that explosive nucleation has occurred in the system and immediately triggers the remelting protection procedure: cooling is immediately stopped, and the heating device is controlled to raise the system temperature. And maintain a constant temperature until detected Restored to zero or a negative value; After the remelting protection procedure ends, the controller restarts the cooling process and adjusts the cooling rate to 50%-80% of the rate before triggering, so as to ensure that the crystallization process always runs in the metastable region on the side close to the solubility curve and suppresses impurity encapsulation.

[0014] A resource recovery system for ceftriaxone sodium mother liquor, applied in a method for resource recovery of ceftriaxone sodium mother liquor, includes: The pretreatment unit is used to remove suspended solids, colloids, some organic impurities and trace heavy metal ions from the ceftriaxone sodium mother liquor; The primary membrane separation unit is used to separate the ceftriaxone sodium mother liquor using a nanofiltration membrane module to obtain a primary permeate and a primary concentrate. The primary concentrate is rich in ceftriaxone sodium and solvents, while the primary permeate contains some small molecule organic matter, salts, and residual solvents. The secondary membrane separation unit is used to pass the obtained primary permeate into the secondary membrane separation unit, and to separate it using a reverse osmosis membrane module to obtain secondary permeate and secondary concentrate; wherein, the secondary concentrate is rich in promoter M precursor, salt and residual solvent, and the secondary permeate is water after preliminary purification; The first refining unit is used to pass the primary concentrate into the first refining unit, where it undergoes low-temperature crystallization, centrifugation, and recrystallization in sequence to obtain high-purity ceftriaxone sodium product. The second refining unit is used to pass the secondary concentrate into the second refining unit, where it undergoes distillation to recover residual solvent, ion exchange, vacuum distillation, and crystallization treatment in sequence to obtain the by-product promoter M. The salt recovery unit is used to pass the salt-containing waste liquid generated after the second refining unit into the salt recovery unit, and then perform evaporation concentration, cooling crystallization and centrifugal drying in sequence to obtain high-purity industrial-grade salt products. The advanced treatment unit is used to receive the secondary permeate from the secondary membrane separation unit and the distillation wastewater from the second purification unit, and to treat the wastewater to meet discharge standards.

[0015] Compared with the prior art, the beneficial effects of the present invention are: This invention achieves precise recovery of solvents, ceftriaxone sodium, and by-product promoter M from the mother liquor throughout the entire process. The treated wastewater meets discharge standards, improving resource utilization. Through precise pretreatment and staged membrane separation, impurities in the mother liquor are effectively removed, reducing membrane fouling risk and improving membrane separation efficiency. Each refining and recovery unit is highly targeted, further improving product recovery rate and purity. The advanced treatment unit achieves efficient wastewater purification, improving treatment efficiency. The pretreatment unit uses a composite coagulant, which has good coagulation effect and requires less dosage. The overall process operates stably with a high degree of automation, reducing labor and operating costs and avoiding direct discharge of ceftriaxone sodium mother liquor, thus achieving pollutant reduction, harmlessness, and resource utilization. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of a method for resource recovery of ceftriaxone sodium mother liquor according to the present invention; Figure 2 This is a schematic diagram of a resource recovery system for ceftriaxone sodium mother liquor according to the present invention. Detailed Implementation

[0017] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0018] Example 1 To address the problems of low resource utilization, poor processing efficiency, high operating costs, and the potential for secondary pollution associated with existing technologies, please refer to [link / reference needed]. Figures 1-2 This embodiment provides the following technical solution: A method for the resource utilization of ceftriaxone sodium mother liquor includes the following steps: S1: The ceftriaxone sodium mother liquor is fed into the pretreatment unit, where it undergoes acid adjustment and coagulation, high-efficiency sedimentation, and precision filtration sequentially to remove suspended solids, colloids, some organic impurities, and trace heavy metal ions. During acid adjustment and coagulation, the pH of the ceftriaxone sodium mother liquor is adjusted to 3.5, and a composite coagulant is added. The composite coagulant consists of polyaluminum chloride, polyacrylamide, and diatomaceous earth in a mass ratio of 5:1:2, with a dosage of 0.6% of the mother liquor mass. The mixture is stirred for 70 minutes. High-efficiency sedimentation is performed in an inclined tube sedimentation tank for 120 minutes. Precision filtration uses a 0.2 μm precision filter. S2: The pretreated mother liquor is passed into the primary membrane separation unit and separated using a nanofiltration membrane module to obtain a primary permeate and a primary concentrate. The nanofiltration membrane module is a nanofiltration membrane with a molecular weight cutoff of 300 Da, and the operating pressure is controlled at 2.0 MPa, the temperature at 30°C, and the flow rate at 80 L / h. The primary concentrate is rich in ceftriaxone sodium and solvents, including ethanol, dichloromethane, acetone, and triethylamine. The primary permeate contains some small molecule organic matter, salts, and residual solvents. S3: The obtained primary permeate is passed into the secondary membrane separation unit and separated using a reverse osmosis membrane module to obtain secondary permeate and secondary concentrate; wherein, the reverse osmosis membrane module is selected with a rejection rate of ≥99%, the operating pressure is controlled at 3.0MPa, the temperature is controlled at 25℃, and the flow rate is controlled at 60L / h; the secondary concentrate is rich in promoter M precursor, salt and residual solvent, and the secondary permeate is water after preliminary purification; S4: The primary concentrate is fed into the first refining unit for distillation to recover solvents. The distillation vacuum is controlled at 0.09 MPa, the temperature at 70°C, and the reflux ratio at 2.3:1. Ethanol (96.2% purity), dichloromethane (95.8% purity), acetone (95.5% purity), and triethylamine (95.3% purity) are recovered. The remaining liquid after distillation is cooled to 2°C and crystallized for 6 hours. Then, it is centrifuged to obtain crude ceftriaxone sodium. The crude ceftriaxone sodium is fed into a recrystallization tank, and an ethanol solution (80% ethanol volume fraction) is added. After heating to dissolve and cooling to crystallize, centrifugation is performed to obtain ceftriaxone sodium product with a purity of 99.6% and a recovery rate of 86%. S5: The secondary concentrate is passed into the second refining unit for residual solvent recovery. The distillation vacuum is controlled at 0.09 MPa, the temperature at 70°C, and the reflux ratio at 1.8:1. The recovered residual solvent has a purity of 95.3%. The remaining liquid after distillation is passed into an ion exchange column filled with D001 type strong acid cation exchange resin. After adsorption for 70 min, 8% ammonia solution is added for desorption. The desorbed liquid is then subjected to vacuum distillation at 0.09 MPa and 70°C for concentration. After cooling and crystallization, the by-product promoter M has a purity of 98% and a recovery rate of 80%. S6: The distilled wastewater generated after treatment with the secondary permeate and by-product promoter M is fed into the advanced treatment unit, where it undergoes advanced oxidation, biological treatment, and activated carbon adsorption treatment in sequence. The treated wastewater meets discharge standards. The advanced oxidation process uses a UV-Fenton advanced oxidation process, with a molar ratio of FeSO4·7H2O to H2O2 of 1:12, a Fenton reagent dosage of 1.0% of the wastewater mass, and UV irradiation for 80 minutes. The biological treatment uses an A / O process, with a 6-hour retention time in the anaerobic tank and a 10-hour retention time in the aerobic tank, and an aeration intensity of 2 m³ / (m²). 2 •h); The adsorption time during activated carbon adsorption is 50min.

[0019] A ceftriaxone sodium mother liquor resource recovery system is applied in a ceftriaxone sodium mother liquor resource recovery method, comprising: The pretreatment unit is used to remove suspended solids, colloids, some organic impurities and trace heavy metal ions from the ceftriaxone sodium mother liquor; The primary membrane separation unit is used to separate the ceftriaxone sodium mother liquor using a nanofiltration membrane module to obtain a primary permeate and a primary concentrate. The primary concentrate is rich in ceftriaxone sodium and solvents, while the primary permeate contains some small molecule organic matter, salts, and residual solvents. The secondary membrane separation unit is used to pass the obtained primary permeate into the secondary membrane separation unit, and to separate it using a reverse osmosis membrane module to obtain secondary permeate and secondary concentrate; wherein, the secondary concentrate is rich in promoter M precursor, salt and residual solvent, and the secondary permeate is water after preliminary purification; The first refining unit is used to recover the solvent from the primary concentrate, and then perform low-temperature crystallization, centrifugation and recrystallization in sequence to obtain high-purity ceftriaxone sodium product and recovered solvent. The second refining unit is used to recover residual solvent from the secondary concentrate, and then perform ion exchange, vacuum distillation and crystallization treatment in sequence to obtain by-product promoter M and recovered solvent. The advanced treatment unit is used to receive the secondary permeate from the secondary membrane separation unit and the distillation wastewater from the second purification unit, and to treat the wastewater to meet discharge standards.

[0020] Example 2 A method for the resource utilization of ceftriaxone sodium mother liquor includes the following steps: S1: The ceftriaxone sodium mother liquor is fed into the pretreatment unit, hydrochloric acid is added to adjust the pH to 3.0, and a composite coagulant is added at a dosage of 0.5% of the mother liquor mass. The mixture is stirred and reacted for 60 minutes. The coagulated mother liquor is then fed into a high-efficiency sedimentation tank and allowed to settle for 90 minutes. The bottom sludge is periodically discharged. The supernatant after sedimentation is then fed into a precision filter with a filtration accuracy of 0.15 μm to obtain the pretreated mother liquor. S2: The pretreated mother liquor is passed into the nanofiltration membrane module of the primary membrane separation unit, with a molecular weight cutoff of 250 Da. The operating pressure is controlled at 1.8 MPa, the temperature at 28 °C, and the flow rate at 60 L / h for nanofiltration separation to obtain primary concentrate and primary permeate. S3: The primary permeate is passed into the reverse osmosis membrane module of the secondary membrane separation unit. The rejection rate is 99.5%. The operating pressure is controlled at 2.8 MPa, the temperature at 22℃, and the flow rate at 40 L / h to carry out reverse osmosis separation and obtain secondary concentrate and secondary permeate. S4: The primary concentrate is passed into the first refining unit for distillation to recover solvents. The distillation vacuum is controlled at 0.085 MPa, the temperature at 65°C, and the reflux ratio at 2:1. Ethanol (96.5%), dichloromethane (96.3%), acetone (96.2%), and triethylamine (96.0%) are recovered. The remaining liquid after distillation is passed into the first low-temperature crystallization tank, cooled to 3°C, and crystallized for 5 hours. Then, it is centrifuged to obtain crude ceftriaxone sodium. The crude ceftriaxone sodium is passed into a recrystallization tank, and an ethanol solution (75% ethanol by volume) is added. After heating to dissolve, the solution is cooled to crystallize and then centrifuged to obtain ceftriaxone sodium product with a purity of 99.3% and a recovery rate of 87%. S5: The secondary concentrate is passed into the second refining unit for residual solvent recovery. The distillation vacuum is controlled at 0.085 MPa, the temperature at 55°C, and the reflux ratio at 2:1. A residual solvent with a purity of 96.1% is recovered. The remaining liquid after distillation is passed into an ion exchange column filled with D001 type strong acid cation exchange resin. After adsorption for 70 min, 7% ammonia solution is added for desorption. The desorbed liquid is then subjected to vacuum distillation at 0.08 MPa and 65°C for concentration. After cooling and crystallization, the by-product promoter M is obtained with a purity of 98.1% and a recovery rate of 81%. S6: The distilled wastewater (COD concentration of 1200 mg / L) generated after treatment of the secondary permeate (COD concentration of 800 mg / L) and by-product promoter M is fed into an advanced oxidation reactor. Fenton's reagent is added, with a molar ratio of FeSO4·7H2O to H2O2 of 1:10 and a dosage of 0.8% of the wastewater mass. The reaction is irradiated with ultraviolet light for 60 min. Then, the wastewater is fed into an A / O biochemical reactor, with a residence time of 4 h in the anaerobic tank and 8 h in the aerobic tank. The aeration intensity in the aerobic tank is 2 m³ / (m²·h). Finally, the wastewater is fed into an activated carbon adsorption tower for adsorption for 30 min.

[0021] Example 3 S1: The ceftriaxone sodium mother liquor is fed into the pretreatment unit, sulfuric acid is added to adjust the pH to 2.8, and the stirring device is turned on for 30 minutes; then the ceftriaxone sodium mother liquor is fed into the coagulation reaction tank, a composite coagulant is added at a dosage of 0.6% of the mother liquor mass, and the mixture is stirred for 60 minutes; the coagulated mother liquor is fed into the high-efficiency sedimentation tank and allowed to settle for 100 minutes, with the bottom sludge being discharged periodically; the supernatant after sedimentation is fed into a precision filter (filtration accuracy of 0.1μm) for filtration to obtain the pretreated mother liquor; S2: The pretreated mother liquor is passed into the nanofiltration membrane module of the primary membrane separation unit. A nanofiltration membrane with a molecular weight cutoff of 220 Da is selected. The operating pressure is controlled at 1.6 MPa, the temperature at 26℃, and the flow rate at 55 L / h for nanofiltration separation to obtain primary concentrate and primary permeate. S3: The primary permeate is passed into the reverse osmosis membrane module of the secondary membrane separation unit. A reverse osmosis membrane with a rejection rate of 99.2% is selected. The operating pressure is controlled at 2.6 MPa, the temperature at 23℃, and the flow rate at 35 L / h to carry out reverse osmosis separation, and secondary concentrate and secondary permeate (preliminarily purified water with a COD concentration of 950 mg / L) are obtained. S4: The primary concentrate is fed into the first refining unit for distillation to recover solvents. The distillation vacuum is controlled at 0.075 MPa, the temperature at 58°C, and the reflux ratio at 2.5:1. Ethanol (97.2%), dichloromethane (96.8%), acetone (96.9%), and triethylamine (96.5%) are recovered. The remaining liquid after distillation is fed into the first low-temperature crystallization tank, cooled to 2°C, and crystallized for 6 hours. Then, it is centrifuged to obtain crude ceftriaxone sodium. The crude ceftriaxone sodium is fed into a recrystallization tank, and an ethanol solution (72% ethanol by volume) is added. After heating to dissolve, the solution is cooled to crystallize and centrifuged to obtain ceftriaxone sodium product with a purity of 99.7% and a recovery rate of 88%. S5: The secondary concentrate is passed into the second refining unit for residual solvent recovery. The distillation vacuum is controlled at 0.07 MPa, the temperature at 55°C, and the reflux ratio at 2:1. The recovered residual solvent has a purity of 96.1%. The remaining liquid after distillation is passed into an ion exchange column filled with D001 type strong acid cation exchange resin. After adsorption for 70 min, 7% ammonia solution is added for desorption. The desorbed liquid is then subjected to vacuum distillation at a vacuum of 0.08 MPa and a temperature of 62°C for concentration. After cooling and crystallization, the by-product promoter M has a purity of 98.5% and a recovery rate of 83.5%. S6: The distilled wastewater (COD concentration of 1300 mg / L) generated after treatment of the secondary permeate (COD concentration of 950 mg / L) and by-product promoter M was fed into an advanced oxidation reactor. Fenton's reagent (molar ratio of FeSO4·7H2O to H2O2 of 1:12) was added at a dosage of 0.9% of the wastewater mass, and the reaction was irradiated with ultraviolet light for 70 min. Then the wastewater was fed into an A / O biochemical reactor, with the anaerobic tank retention time controlled at 5 h and the aerobic tank retention time at 9 h, and the aeration intensity of the aerobic tank at 2.2 m³ / (m²·h). Finally, the wastewater was fed into an activated carbon adsorption tower for adsorption for 40 min.

[0022] Comparative Example A method for the resource utilization of ceftriaxone sodium mother liquor includes the following steps: S1: Large particulate impurities are removed by simple filtration with a filtration accuracy of 0.45μm. Polyaluminum chloride, a single coagulant, is added at a dosage of 1.2% of the mother liquor mass. After stirring and reacting for 90 min, the mixture is allowed to settle for 180 min to obtain the pretreated mother liquor. S2: The pretreated mother liquor is fed into the biochemical reactor and treated using the conventional activated sludge process, with a retention time of 24 hours. S3: Separation was performed using a nanofiltration membrane with a molecular weight cutoff of 500 Da, at an operating pressure of 2.5 MPa and a temperature of 35 °C, to obtain a concentrate and a permeate. S4: Recrystallization recovery: The concentrate is recovered using a single recrystallization process to obtain ceftriaxone sodium product with a purity of 97.5%. S5: The permeate is directly evaporated and crystallized to obtain byproduct accelerator M with a purity of 95%; S6: The wastewater generated from biochemical treatment and evaporation crystallization is treated by single activated carbon adsorption.

[0023] The treatment methods described in Examples 1, 2, 3, and the comparative example were used to treat ceftriaxone sodium mother liquor produced by a pharmaceutical factory. This ceftriaxone sodium mother liquor had a COD concentration of 120,000 mg / L, a salt content of 8% (mainly sodium sulfate), and contained ceftriaxone sodium (approximately 3.0%), 7-aminocephalosporanic acid (approximately 1.5%), triazine ring (approximately 1.0%), and trace amounts of heavy metal ions (lead, cadmium, etc., totaling approximately 0.0015%). The treatment results are shown in the table below. As can be seen from the comparison table above, the treatment method and system of the present invention are significantly superior to traditional treatment processes in terms of pretreatment impurity removal rate, purity and recovery rate of each valuable component, and effluent treatment effect. The present invention achieves synergistic and efficient recovery of multiple components from ceftriaxone sodium mother liquor, and the effluent meets discharge standards, conforming to the concept of green chemical development and possessing broad prospects for industrial application.

[0024] Example 4: In step S2, the primary membrane separation unit is equipped with an intelligent circulating flow control system, which includes a programmable logic controller (PLC), a variable frequency circulating pump, and pressure sensors, flow sensors, and temperature sensors respectively installed at the inlet and outlet of the membrane module and the permeation side. The PLC is configured to execute a dynamic flux maintenance strategy based on electro-viscous resistance compensation, the specific steps of which include: Continuous real-time monitoring of transmembrane pressure difference in nanofiltration membrane modules Permeation flux and mother liquor temperature ; The PLC calculates the target circulation flow rate at the current moment in real time according to the following calculation model. : in, The preset baseline circulation flow rate; The dynamic viscosity of the mother liquor at the current temperature. Viscosity at reference temperature; For real-time transmembrane pressure difference; This is the preset osmotic pressure compensation value; For real-time permeation flux; This is the inherent resistance constant of the cleaning membrane; and This is an empirical coefficient determined based on the concentration of ceftriaxone sodium in the mother liquor; This represents an exponential function with the natural constant e as its base. and These are all dimensionless empirical coefficients and must be experimentally calibrated based on the characteristics of the mother liquor; in this embodiment... The value range is 1.2-1.4 (1.3 in this embodiment), which is used to correct the nonlinear effect of viscosity on Reynolds number under non-Newtonian fluid characteristics; The value ranges from 0.1 to 0.2 (0.15 in this embodiment), and is used to adjust the system's response sensitivity to changes in membrane fouling resistance; The PLC calculates... The frequency of the variable frequency circulating pump is adjusted in real time so that the actual circulating flow rate in the membrane module tracks the target circulating flow rate, thereby ensuring that the shear stress on the membrane surface is sufficient to strip the concentration polarization layer while compensating for fluctuations in fluid viscous resistance caused by temperature changes.

[0025] In this embodiment, in addition to conventional pressure, flow, and temperature sensors, the control system also incorporates an online conductivity sensor (range 0-100 mS / cm) on the inlet side of the nanofiltration membrane module. The PLC controller uses the real-time collected conductivity values ​​as the basis for its operation. Using a pre-set conductivity-osmotic pressure conversion formula Real-time estimation of osmotic pressure compensation value (where k is the pre-approved conductivity-osmotic pressure conversion factor), thereby eliminating the calculation error of effective transmembrane pressure difference caused by mother liquor concentration.

[0026] Specifically, at the pressure sensing level, the system installs high-frequency response industrial-grade pressure transmitters at the inlet of the nanofiltration membrane module, the outlet of the concentrate, and on the permeate side pipeline. These transmitters employ piezoresistive or capacitive sensing elements, enabling real-time capture of the static pressure and pulsation of the fluid at both ends of the membrane channel at millisecond-level sampling rates. The analog current signal output by the sensors is transmitted to the control cabinet via shielded cables and then enters the central processing unit through a high-precision analog-to-digital converter. The system accurately obtains the effective transmembrane pressure differential acting on the membrane separation functional layer by calculating the difference between the inlet and outlet pressures in real time and subtracting the hydraulic resistance along the flow path and the permeate side back pressure. This parameter is fundamental to evaluating the balance between membrane separation driving force and resistance.

[0027] Secondly, at the fluid state sensing level, a high-precision resistance temperature sensor (e.g., PT100 or PT1000) is installed probing into the inlet manifold of the membrane module. To eliminate measurement lag caused by heat conduction from the pipe wall, the sensor probe is designed to directly contact the turbulent region at the center of the fluid, ensuring real-time and accurate feedback of the bulk thermodynamic temperature of the mother liquor. Given the extremely high sensitivity of the dynamic viscosity of the ceftriaxone sodium mother liquor to temperature changes, this temperature signal is the core variable for subsequent rheological resistance compensation.

[0028] In addition, electromagnetic flowmeters are installed in the circulation loop of the membrane module to measure the cross-flow velocity (i.e., circulation flow rate) across the membrane surface in real time; a micro-flowmeter is installed at the permeate outlet to monitor the system's real-time production capacity (permeation flux). All sensor data is aggregated into the system's programmable logic controller (PLC). The PLC integrates a high-speed floating-point arithmetic unit, capable of running nonlinear control models. The actuator consists of a circulation pump driven by a high-power frequency converter. The frequency converter maintains bidirectional high-speed communication with the PLC via an industrial fieldbus, receiving frequency commands and providing real-time feedback on the motor's operating current, torque, and actual speed.

[0029] During nanofiltration separation, as the equipment operates continuously, some of the mechanical energy input by the circulating pump is converted into internal energy, causing the mother liquor temperature to gradually increase; alternatively, the mother liquor temperature may decrease due to the diurnal temperature range and fluctuations in the upstream feed temperature. The dynamic viscosity of a liquid is a function of temperature. For ceftriaxone sodium mother liquor containing high concentrations of organic matter and inorganic salts, as the temperature decreases, the intermolecular distance shrinks, and the intermolecular forces strengthen, macroscopically manifesting as fluid thickening and a non-linear exponential increase in viscosity.

[0030] In traditional control modes, if the circulating flow rate is kept constant, the Reynolds number of the fluid in the membrane channel will decrease significantly when the temperature decreases and the viscosity increases. A lower Reynolds number means reduced turbulence and decreased momentum exchange between fluid layers, leading to a decrease in the efficiency of fluid scouring and shearing against the membrane surface. This makes it easier for a thicker concentration polarization layer to form on the membrane surface, accelerating membrane fouling.

[0031] Therefore, the PLC of this system has a pre-set mathematical model based on the experimentally calibrated viscosity-temperature characteristics of ceftriaxone sodium mother liquor. In each control cycle, the PLC first reads the real-time temperature data and uses this model to calculate the dynamic viscosity of the fluid under the current operating conditions. Subsequently, the controller compares this real-time viscosity with a reference viscosity at a preset reference temperature (e.g., 25 degrees Celsius) to generate a viscosity correction factor that reflects the changing trend of fluid flow resistance.

[0032] When a decrease in temperature leads to an increase in viscosity, the system must provide greater fluid kinetic energy to maintain the same turbulence intensity and shear stripping capacity on the membrane surface as under baseline conditions. Therefore, the control algorithm calculates a positive flow gain coefficient, instructing the system to increase the circulation flow rate. By artificially increasing the flow rate, the Reynolds number is forcibly increased to offset the adverse effects of increased viscosity. Conversely, when an increase in temperature leads to a decrease in viscosity, the system appropriately reduces the flow rate, avoiding unnecessary energy consumption and excessive shearing of heat-sensitive materials while ensuring cleaning effectiveness, thus achieving energy-efficient process optimization.

[0033] Besides viscosity, concentration polarization also occurs during membrane separation. Under pressure, solute molecules such as ceftriaxone sodium and triazine rings in the mother liquor are trapped on the membrane surface, while solvent molecules permeate through the membrane pores. This results in the formation of a boundary layer on the high-pressure side of the membrane with a solute concentration much higher than that of the bulk solution. This boundary layer not only generates reverse osmotic pressure, offsetting the operating pressure, but also increases the resistance to fluid permeation. If this boundary layer is not removed in time by sufficient hydraulic shear, it will gradually densify and evolve into an irreversible gel layer, leading to a drop in membrane flux.

[0034] This system introduces a dynamic compensation strategy for membrane microfouling resistance. The PLC collects real-time transmembrane pressure differential and permeate flux data, and combines this with an osmotic pressure compensation value estimated from real-time concentration to calculate the current unit flux filtration resistance. This parameter reflects the degree of membrane fouling. Under ideal clean conditions, this resistance value should be close to the membrane's inherent resistance. However, as operation progresses, once contaminants begin to accumulate on the membrane surface, this resistance value will show an upward trend.

[0035] To achieve sensitive detection and rapid suppression of early signs of membrane fouling, this control model employs a nonlinear gain algorithm based on the natural exponential function. Membrane fouling often exhibits self-accelerating characteristics; even a small increase in drag can foreshadow severe fouling. Therefore, the system must possess a significant responsiveness to changes in drag.

[0036] When the PLC detects a slight upward trend in the real-time resistance relative to the cleaning membrane resistance, the exponential logic amplifies this signal rapidly, generating a flow rate increase command. This command is then transmitted to the variable frequency circulating pump, causing a significant increase in pump speed within a short period, creating a high-intensity cross-flow environment inside the membrane module. The high-speed fluid generates strong tangential shear stress on the membrane surface. This shear stress physically thins and peels away the concentration polarization layer adhering to the membrane surface, re-entraining accumulated solute molecules into the main turbulent flow and carrying them away, thus achieving online hydraulic cleaning of the membrane surface. Once the resistance value drops, the system automatically restores the flow rate to normal levels. This pulse-like adjustment effectively prevents deep clogging of the membrane pores.

[0037] The viscosity compensation logic and resistance compensation logic described above are synthesized in real time within the PLC through a multivariate coupling model. The PLC continuously refreshes the calculation results with an extremely short scan cycle (e.g., every 100 milliseconds) and outputs the real-time target circulating flow rate value.

[0038] The target flow rate is calculated by multiplying the baseline flow rate by a viscosity correction factor, and then by a resistance compensation factor. This means that the final flow rate setting is the optimal solution after comprehensively considering both fluid rheological requirements and membrane surface cleaning requirements. For example, in the initial stage of system startup, the membrane surface is clean but the feed liquid temperature is low, and the system mainly sets a higher flow rate based on the viscosity compensation logic. As the operating time progresses, the temperature gradually increases, causing the viscosity to decrease. The system should reduce the flow rate, but if the membrane surface resistance begins to increase at this time, the resistance compensation logic will intervene and forcibly require an increase in the flow rate.

[0039] The calculated target flow rate is then used as a setpoint input to the PID (Proportional-Integral-Derivative) control module inside the PLC. The PID module uses the actual circulating flow rate fed back from the flow sensor as the process value and performs rapid deviation adjustment. If the actual flow rate is lower than the target value (e.g., due to natural flow rate decay caused by increased membrane resistance), the PID controller will immediately output a higher frequency command to drive the variable frequency pump to accelerate compensation.

[0040] Example 5: The crystallization process in step S4 employs an adaptive metastable region cruise control strategy based on turbidity change rate feedback. This strategy does not rely on a preset fixed cooling curve, but rather the controller executes the following logical steps: Preset turbidity change rate threshold K and temperature rollback value In this embodiment, to avoid interference from stirring bubbles, the turbidity meter is installed on a bypass line with de-bubbling function, and the sampling frequency is set to 2Hz. Based on the metastable region width determined by the small-scale experiment, the turbidity change rate threshold K is set to 3.0-5.0 NTU / s (4.0 NTU / s in this embodiment), which represents the critical rate for explosive nucleation. A temperature rollback value is also set. The temperature range is 2.0-4.0℃ (3.0℃ in this embodiment), which is sufficient to redissolve the tiny crystal nuclei using the Gibbs-Thomson effect; During the cooling process, the turbidity value of the crystallization system was collected at a fixed sampling period, and the first derivative of turbidity with time was calculated. ; Real-time calculation Compare with the threshold K; like If the temperature is less than K, the controller maintains the current cooling rate; like If the temperature is greater than or equal to K, the controller determines that explosive nucleation has occurred in the system and immediately triggers the remelting protection procedure: cooling is immediately stopped, and the heating device is controlled to raise the system temperature. And maintain a constant temperature until detected Restore to zero or a negative value; After the remelting protection procedure ends, the controller restarts the cooling process and adjusts the cooling rate to 50%-80% of the rate before triggering, so as to ensure that the crystallization process always runs in the metastable region on the side close to the solubility curve and suppresses impurity encapsulation.

[0041] In the first refining unit, the crystallization extraction of high-purity ceftriaxone sodium from the primary concentrate after nanofiltration is a crucial step determining the final product quality. Traditional industrial crystallization processes often rely on pre-set, fixed cooling profiles (such as linear or segmented cooling). However, the ceftriaxone sodium mother liquor has a complex composition, with significant fluctuations in impurity content and salt concentration between different batches, leading to substantial changes in the width of its metastable region. Fixed cooling procedures cannot detect these dynamic changes, easily causing the crystallization process to deviate from the optimal path: for example, excessively rapid cooling causes the system to move out of the metastable region and into the unstable region, triggering significant nucleation and resulting in fine product particles containing a large number of triazine ring impurities; excessively slow cooling leads to low production efficiency.

[0042] Therefore, this invention employs an adaptive metastable region cruise control strategy based on turbidity change rate feedback.

[0043] A high-sensitivity online light scattering turbidity analyzer is provided for installation inside the crystallization vessel. In crystallization kinetics, changes in the turbidity of a solution are the most direct and sensitive physical quantity reflecting the precipitation state of solid particles. This turbidity probe operates based on the Tyndall effect or Mie scattering principle, emitting a light beam of a specific wavelength into the solution. When crystal nuclei or crystal particles are present in the solution, the light beam will be scattered, and the intensity of the scattered light is positively correlated with the number density and particle size of the suspended particles.

[0044] In the initial stage of cooling crystallization, the solution is in a clear or metastable state with extremely low and stable turbidity. As the temperature decreases, supersaturation is established, crystal nuclei begin to form, and the turbidity reading begins to rise. The core innovation of this system lies in the fact that the controller not only reads the absolute value of turbidity, but also calculates the first derivative of turbidity with time in real time, i.e., the rate of change of turbidity.

[0045] The turbidity change rate represents the acceleration of the nucleation rate. If the crystal grows gently within the metastable region, or undergoes controlled secondary nucleation, the number of particles increases slowly, and the turbidity exhibits a steady linear increase with a small rate of change that remains within a safe range. However, once the system inadvertently enters the unstable region and explosive nucleation occurs, a large number of tiny crystal nuclei are generated instantaneously in the solution. This abrupt change causes the solution to become turbid rapidly within seconds, with the turbidity value soaring dramatically. At this point, the calculated turbidity change rate will instantly exceed the preset safety threshold.

[0046] The execution logic of this control system specifically includes four stages: steady-state cruise, burst recognition, reverse intervention, and path correction.

[0047] Phase 1: Steady-state cruise monitoring.

[0048] After the crystallization process starts, the controller controls the jacket to cool down at a preset initial rate, while simultaneously acquiring turbidity signals at a high frequency (e.g., 10 times per second) and calculating the rate of change. The controller continuously compares the real-time rate of change with a preset threshold. As long as the rate of change is less than the threshold, the system determines that the current nucleation rate is within a controllable range, and the crystals are mainly undergoing heterogeneous nucleation or crystal growth, which is a benign crystallization process. At this point, the system maintains the current cooling operation, and may even fine-tune the acceleration according to the optimization algorithm to improve production efficiency.

[0049] Phase Two: Identification and Breakdown of Explosive Nucleation.

[0050] At any given moment, due to rapid cooling, uneven local concentration, or impurity induction, the controller detects a sudden increase in the turbidity change rate exceeding the threshold, and the system immediately determines that an explosive nucleation accident has occurred. Without intervention, these massively generated microcrystals will adsorb impurities from the mother liquor, resulting in extremely poor particle size distribution in the final product. In this case, the controller will immediately trigger the highest-priority re-dissolution protection procedure.

[0051] Phase 3: Reverse thermodynamic intervention (redissolution protection).

[0052] First, the controller immediately cuts off the refrigerant supply, forcibly stopping the cooling process to prevent further deterioration of the supersaturation. Then, the controller instructs the heating system to activate, introducing heat medium into the jacket, forcing the material temperature inside the crystallizer to rise in reverse by a preset amount (i.e., the temperature rollback value, for example, an increase of 2 degrees Celsius) in a very short time, and maintaining this temperature at a constant level.

[0053] The physicochemical mechanism behind this heating process utilizes the Ostwald ripening effect and its reverse process. According to the Gibbs-Thomson effect, the solubility of solid particles is related to their particle size. The smaller the particle size, the larger the specific surface area, the higher the surface energy, and the greater the solubility. The countless microcrystals generated in the early stages of explosive nucleation are extremely small and thermodynamically unstable. When the controller forcibly raises the temperature, the overall supersaturation of the solution decreases, or even turns into an unsaturated state. At this time, the newly formed, thermodynamically unstable microcrystals preferentially dissolve and return to the liquid phase as solute molecules; while the larger, more structurally complete crystal particles that existed before the explosion, although undergoing surface dissolution, are largely preserved. This process effectively filters the nucleus population, eliminating fine crystals that could potentially trap impurities, purifying the crystallization environment, and bringing the system back to a thermodynamically stable state.

[0054] Phase 4: Path Correction and Adaptive Restart.

[0055] During the remelting protection procedure, the controller continuously monitors the turbidity change rate. As the fine crystals dissolve, the upward trend in turbidity is halted, and the change rate gradually falls back to zero or even becomes negative. Once the controller confirms that the system has stabilized, it will terminate the remelting procedure and prepare to restart the cooling process.

[0056] At this point, the system exhibits adaptive learning capabilities. It determines that the previous cooling rate was too rapid for the current mother liquor system, causing the accumulation of supersaturation to exceed the rate of crystal growth. Therefore, the controller automatically invokes a correction algorithm to adjust the cooling rate to a certain proportion of the pre-triggered rate (e.g., reducing it to 60% to 80% of the original rate). Subsequently, the system restarts cooling at this new, gentler rate. This ensures that the crystallization process always operates close to one side of the solubility curve, allowing solute molecules sufficient time to arrange themselves orderly on the crystal lattice surface, and excluding impurity molecules such as triazine rings from the crystal lattice.

[0057] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0058] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention.

Claims

1. A method for the resource utilization of ceftriaxone sodium mother liquor, characterized in that, Includes the following steps: S1: The ceftriaxone sodium mother liquor is introduced into the pretreatment unit and sequentially filtered, pH value adjusted and suspended solids removed to obtain the pretreated solution; S2: The pretreated mother liquor is passed into the primary membrane separation unit and separated using a nanofiltration membrane module to obtain primary permeate and primary concentrate. S3: The obtained primary permeate is passed into the secondary membrane separation unit and separated using a reverse osmosis membrane module to obtain secondary permeate and secondary concentrate; S4: The first-stage concentrate is fed into the first refining unit, where solvents are first recovered by distillation, and then subjected to low-temperature crystallization, centrifugation and recrystallization to obtain high-purity ceftriaxone sodium product. S5: Pass the secondary concentrate into the second refining unit, and sequentially perform distillation to recover residual solvent, ion exchange, vacuum distillation and crystallization to obtain by-product promoter M; S6: The distilled wastewater generated after the secondary permeate and by-product promoter M are fed into the advanced treatment unit, where it undergoes advanced oxidation, biochemical treatment, and activated carbon adsorption treatment in sequence. The treated wastewater meets the discharge standards.

2. The method for resource utilization of ceftriaxone sodium mother liquor according to claim 1, characterized in that, During the pH adjustment process, the pH of the ceftriaxone sodium mother liquor is adjusted to 2.5-3.5, and a composite coagulant is added. The composite coagulant is composed of polyaluminum chloride, polyacrylamide, and diatomaceous earth in a mass ratio of 5:1:

2. The dosage of the composite coagulant is 0.4%-0.6% of the mass of the mother liquor, and the mixture is stirred for 50-70 minutes. High-efficiency sedimentation is carried out in an inclined tube sedimentation tank for 80-120 minutes. Precision filtration is carried out using a precision filter with a filtration accuracy of 0.1-0.2 μm.

3. The method for resource utilization of ceftriaxone sodium mother liquor according to claim 1, characterized in that, The nanofiltration membrane module uses a nanofiltration membrane with a molecular weight cutoff of 200-300 Da, and the operating pressure is controlled at 1.5-2.0 MPa, the temperature is controlled at 25-30℃, and the flow rate is controlled at 50-80 L / h. The primary concentrate is rich in ceftriaxone sodium and solvents, including ethanol, dichloromethane, acetone and triethylamine. The primary permeate contains some small molecule organic matter, salts and residual solvents.

4. The method for resource utilization of ceftriaxone sodium mother liquor according to claim 1, characterized in that, The reverse osmosis membrane module uses a reverse osmosis membrane with a rejection rate of ≥99%, and the operating pressure is controlled at 2.5-3.0 MPa, the temperature is controlled at 20-25℃, and the flow rate is controlled at 30-60 L / h. The secondary concentrate is rich in the promoter M precursor, salt and residual solvent, and the secondary permeate is water after preliminary purification.

5. The method for resource utilization of ceftriaxone sodium mother liquor according to claim 1, characterized in that, The reverse osmosis membrane module uses a reverse osmosis membrane with a rejection rate of ≥99%, and the operating pressure is controlled at 2.5-3.0 MPa, the temperature at 20-25℃, and the flow rate at 30-60 L / h. The ion exchange uses D001 type strong acid cation exchange resin, with an adsorption time of 50-70 min, and ammonia water with a mass concentration of 5%-8% is used as the desorbent. The vacuum degree of vacuum distillation is controlled at 0.08-0.09 MPa, and the temperature is controlled at 60-70℃.

6. The method for resource utilization of ceftriaxone sodium mother liquor according to claim 1, characterized in that, The evaporation and concentration process uses a triple-effect evaporator, with the evaporation temperature controlled at 95-110℃ and the vacuum degree controlled at 0.06-0.08MPa, evaporating and concentrating to a salt concentration of 30%-40%; cooling and crystallization process involves cooling to 10-15℃ and crystallization time of 3-5 hours; centrifugal drying is performed using hot air drying, with the temperature controlled at 80-90℃ and drying time of 1.5-2.5 hours.

7. The method for resource utilization of ceftriaxone sodium mother liquor according to claim 1, characterized in that, The advanced oxidation process employs UV-Fenton advanced oxidation, with a molar ratio of FeSO4·7H2O to H2O2 of 1:10-12. The Fenton reagent dosage is 0.6%-1.0% of the wastewater mass, and the UV irradiation reaction lasts for 50-80 minutes. The biological treatment uses an A / O process, with an anaerobic tank retention time of 4-6 hours and an aerobic tank retention time of 7-10 hours. The aeration intensity in the aerobic tank is 1.8-2.5 m³ / (m·h). The activated carbon adsorption time is 30-50 minutes.

8. The method for resource utilization of ceftriaxone sodium mother liquor according to claim 1, characterized in that, In step S2, the primary membrane separation unit is equipped with an intelligent circulating flow control system, which includes a programmable logic controller (PLC), a variable frequency circulating pump, and pressure sensors, flow sensors, and temperature sensors respectively installed at the inlet and outlet of the membrane module and the permeation side. The PLC is configured to execute a dynamic flux maintenance strategy based on electro-viscous resistance compensation, the specific steps of which include: Continuous real-time monitoring of transmembrane pressure difference in nanofiltration membrane modules Permeation flux and mother liquor temperature ; The PLC calculates the target circulation flow rate at the current moment in real time according to the following calculation model. : in, The preset baseline circulation flow rate; The dynamic viscosity of the mother liquor at the current temperature. Viscosity at reference temperature; For real-time transmembrane pressure difference; This is the preset osmotic pressure compensation value; For real-time permeation flux; This is the inherent resistance constant of the cleaning membrane; and This is an empirical coefficient determined based on the concentration of ceftriaxone sodium in the mother liquor; Represented by the natural constant An exponential function with base 0; The PLC calculates... The frequency of the variable frequency circulating pump is adjusted in real time so that the actual circulating flow rate in the membrane module tracks the target circulating flow rate, thereby ensuring that the shear stress on the membrane surface is sufficient to strip the concentration polarization layer while compensating for fluctuations in fluid viscous resistance caused by temperature changes.

9. The method for resource utilization of ceftriaxone sodium mother liquor according to claim 1, characterized in that, The crystallization process in step S4 employs an adaptive metastable region cruise control strategy based on turbidity change rate feedback. This strategy does not rely on a preset fixed cooling curve, but rather the controller executes the following logical steps: Preset turbidity change rate threshold and temperature rollback value ; During the cooling process, the turbidity value of the crystallization system was collected at a fixed sampling period, and the first derivative of turbidity with time was calculated. ; Real-time calculation With the threshold Compare; like Less than The controller maintains the current cooling rate; like Greater than or equal to The controller determines that explosive nucleation has occurred in the system and immediately triggers the remelting protection procedure: it immediately stops cooling and controls the heating device to raise the system temperature. And maintain a constant temperature until detected Restore to zero or a negative value; After the remelting protection procedure ends, the controller restarts the cooling process and adjusts the cooling rate to 50%-80% of the rate before triggering, so as to ensure that the crystallization process always runs in the metastable region on the side close to the solubility curve and suppresses impurity encapsulation.

10. A resource recovery system for ceftriaxone sodium mother liquor, applied in the resource recovery method for ceftriaxone sodium mother liquor as described in claim 7, characterized in that, include: The pretreatment unit is used to remove suspended solids, colloids, some organic impurities and trace heavy metal ions from the ceftriaxone sodium mother liquor; The primary membrane separation unit is used to separate the ceftriaxone sodium mother liquor using a nanofiltration membrane module to obtain a primary permeate and a primary concentrate. The primary concentrate is rich in ceftriaxone sodium and solvents, while the primary permeate contains some small molecule organic matter, salts, and residual solvents. The secondary membrane separation unit is used to pass the obtained primary permeate into the secondary membrane separation unit, and to separate it using a reverse osmosis membrane module to obtain secondary permeate and secondary concentrate; wherein, the secondary concentrate is rich in promoter M precursor, salt and residual solvent, and the secondary permeate is water after preliminary purification; The first refining unit is used to distill and recover ethanol, dichloromethane, acetone and triethylamine from the primary concentrate, and then perform low-temperature crystallization, centrifugation and recrystallization to obtain high-purity ceftriaxone sodium product. The second refining unit is used to recover residual solvent from the secondary concentrate, and then perform ion exchange, vacuum distillation and crystallization treatment in sequence to obtain by-product promoter M. The advanced treatment unit is used to receive the secondary permeate from the secondary membrane separation unit and the distillation wastewater from the second purification unit, and to treat the wastewater to meet discharge standards.

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