CN-121988179-A - High-flux nanofiltration membrane for separating antibiotics and salts and preparation method thereof

Abstract

The invention discloses a high-flux nanofiltration membrane for separating antibiotics and salts and a preparation method thereof, which belong to the technical field of membrane separation, wherein a polyhydric phenol monomer containing a rigid twisted structure is used as a water phase monomer, trimesoyl chloride is used as a first oil phase monomer, at least one of terephthaloyl chloride and 1,2,4, 5-benzene tetra (formyl chloride) is used as a second oil phase monomer, and the water phase monomer and the first oil phase monomer and the second oil phase monomer are subjected to interfacial polymerization reaction for two times on a porous support membrane respectively to prepare the high-flux nanofiltration membrane for separating the antibiotics and the salts. According to the invention, a specific interfacial polymerization monomer is selected, and an interfacial polymerization process is improved, so that the microporous structure and the surface charge of the nanofiltration membrane separation layer of the product are directionally constructed, and the efficient interception of target antibiotics and the ultrahigh penetration of water molecules and inorganic salts are realized.

Inventors

• ZHANG CHUANQI
• ZHANG LIN
• TAO YUXIN
• Lu Danhao
• YAO ZHIKAN
• LI GE
• PENG XINSHENG

Assignees

• 浙江大学

Dates

Publication Date

20260508

Application Date

20260126

Claims (9)

1. 1. The preparation method of the high-flux nanofiltration membrane for separating antibiotics and salts is characterized by comprising the following steps of: (1) Preparing an aqueous phase solution by taking a polyhydric phenol monomer containing a rigid torsion structure as an aqueous phase monomer and taking the polyhydric phenol monomer containing the rigid torsion structure and an acid binding agent, preparing a first oil phase solution by taking trimesoyl chloride as a first oil phase monomer, and preparing a second oil phase solution by taking at least one of terephthaloyl chloride and 1,2,4, 5-benzene tetra (formyl chloride) as a second oil phase monomer; (2) After the porous support membrane is soaked by the aqueous phase solution, removing superfluous aqueous phase solution on the surface of the porous support membrane, placing the first oil phase solution on the membrane surface treated by the aqueous phase solution, enabling the first oil phase monomer and the aqueous phase monomer to undergo primary interfacial polymerization reaction to prepare a nascent membrane, placing the second oil phase solution on the surface of the nascent membrane, and performing secondary interfacial polymerization reaction by utilizing the second oil phase monomer and the aqueous phase monomer, and after the reaction is finished, cleaning and crosslinking to prepare the high-flux nanofiltration membrane for separating antibiotics and salts; wherein the primary interfacial polymerization reaction time is longer than the secondary interfacial polymerization reaction time.
2. 2. The method for preparing high-flux nanofiltration membrane for antibiotic and salt separation according to claim 1, wherein the polyhydric phenol monomer having rigid twist structure is selected from bisphenol fluorene, 9-BIs (4-hydroxy-3-methylphenyl) fluorene, 3', at least one of 3' -tetramethyl-1, 1 '-spirobi (indane) -6,6' -diol, 5', 6' -tetrahydroxy-3, 3 '-tetramethyl-1, 1' -spirobiindane.
3. 3. The method for preparing the high-flux nanofiltration membrane for separating antibiotics and salts according to claim 1, wherein the porous support membrane comprises a polysulfone ultrafiltration membrane, a polyethersulfone ultrafiltration membrane, a polyacrylonitrile ultrafiltration membrane, a cellulose acetate ultrafiltration membrane, a polyethylene ultrafiltration membrane or a polyamide ultrafiltration membrane.
4. 4. The method for preparing the high-flux nanofiltration membrane for separating antibiotics and salts according to claim 1, wherein the acid binding agent contained in the aqueous phase solution is at least one of sodium hydroxide, potassium hydroxide, pyridine, triethylamine, N-diisopropylethylamine, sodium carbonate and trisodium phosphate dodecahydrate, the mass concentration of the polyhydric phenol monomer containing the rigid torsion structure in the aqueous phase solution is 1-10 wt%, and the mass concentration of the acid binding agent is 0.1-5 wt%.
5. 5. The method for preparing a high-flux nanofiltration membrane for antibiotic and salt separation according to claim 1, wherein the solvent of the first oil phase solution and the solvent of the second oil phase solution are each independently selected from toluene, isopar G or n-hexane.
6. 6. The method for preparing the high-flux nanofiltration membrane for separating antibiotics and salts according to claim 1, wherein the mass concentration of the first oil phase monomer in the first oil phase solution is 0.1-5 wt%, the mass concentration of the second oil phase monomer in the second oil phase solution is 0.1-1 wt%, the condition of the primary interfacial polymerization reaction is room temperature, the condition of the secondary interfacial polymerization reaction is room temperature, and the condition of the secondary interfacial polymerization reaction is 1-5 min.
7. 7. The method for preparing the high-flux nanofiltration membrane for separating antibiotics and salts according to claim 1, wherein the crosslinking is carried out at a temperature of 50-100 ℃ for a time of 1-15 min.
8. 8. The high-flux nanofiltration membrane for antibiotic and salt separation according to any one of claims 1 to 7.
9. 9. A method for separating antibiotics and salts, characterized in that the interception of antibiotics and the permeation of salts are achieved by treating a solution containing salts and antibiotics with a high flux nanofiltration membrane for separating antibiotics and salts according to claim 8.

Description

High-flux nanofiltration membrane for separating antibiotics and salts and preparation method thereof Technical Field The invention belongs to the technical field of membrane separation, and particularly relates to a high-flux nanofiltration membrane for separating antibiotics and salts and a preparation method thereof. Background The antibiotics can effectively inhibit or kill pathogenic microorganisms, and play an irreplaceable role in the fields of modern medical treatment, livestock breeding and the like. At present, most antibiotics such as tetracycline hydrochloride, doxorubicin and the like are mainly prepared by a microbial fermentation method, and inorganic salts such as sodium chloride and the like are often added to maintain the stability and activity of a fermentation system. Therefore, in order to obtain high purity antibiotic products and to treat saline antibiotic fermentation wastewater, efficient separation of target antibiotics from inorganic salts is required. The nanofiltration is used as a high-efficiency, energy-saving and environment-friendly separation technology, has the advantages of low operation pressure and high separation precision, and has good application prospect in the aspects of separation of antibiotics and salts. The prior commercial nanofiltration membrane is usually a polyamide composite membrane prepared by adopting piperazine and trimesoyl chloride to carry out interfacial polymerization reaction. However, in the interfacial polymerization process, the reaction of the conventional amine monomer and the acid chloride monomer at the water-oil interface is extremely rapid and the diffusion thereof is difficult to precisely control, resulting in a relatively dense and thick separation layer of the formed composite membrane, thereby reducing the permeability of water molecules and inorganic salts and eventually limiting the separation efficiency of salts/antibiotics. By designing the structure and the composition of the interfacial polymerization reaction monomer and improving the interfacial polymerization process, the structure and the electrical property of the separation layer of the formed composite membrane can be regulated and controlled so as to ensure higher permeability to water molecules and inorganic salts and improve the retention rate of the nanofiltration membrane to antibiotics, thereby realizing effective separation and efficient treatment of the salts/antibiotics. In the prior art, a few membrane materials for antibiotic desalination are reported, for example, chinese patent document with publication number of CN119524637A discloses a preparation method of MOF/MXene composite membrane and application of antibiotic desalination, firstly, 2-amino terephthalic acid and zinc acetate dihydrate ZnBDC-NH 2 MOF nano-sheet are utilized, then MXene and ZnBDC-NH 2 MOF nano-sheet are mixed and dispersed to prepare colloid suspension, and vacuum assisted self-assembly technology is utilized to prepare MXene intercalated ZnBDC-NH 2 MOF nano-sheet composite membrane for antibiotic desalination. But it may present a risk in terms of separation stability and metal leaching. The invention discloses a low-pressure nanofiltration membrane and a preparation method thereof, wherein aminopiperidine is used as a water phase monomer, an ultra-microporous polyamide membrane with stable structure and high selectivity is constructed, and the nanofiltration membrane prepared by the method maintains the rapid water transmission characteristic while accurately separating divalent salt ions, so that the separation of single/divalent salts and the effective removal of antibiotics are realized under low-pressure operation. However, the aminopiperidine monomer has high cost, and the long-term stability of the nanofiltration membrane operation is yet to be verified. Therefore, there is a need to develop a structurally stable nanofiltration membrane that enables efficient entrapment of target antibiotics and ultra-high permeation of water molecules and inorganic salts. Disclosure of Invention Aiming at the defects existing in the prior art, the invention aims to provide a preparation method of a high-flux nanofiltration membrane for separating antibiotics and salts, and the obtained nanofiltration membrane has stable structure and excellent water flux and salt/antibiotic selectivity. The technical scheme adopted is as follows: the preparation method of the high-flux nanofiltration membrane for separating antibiotics and salts comprises the following steps: (1) Preparing an aqueous phase solution by taking a polyhydric phenol monomer containing a rigid torsion structure as an aqueous phase monomer and taking the polyhydric phenol monomer containing the rigid torsion structure and an acid binding agent, preparing a first oil phase solution by taking trimesoyl chloride as a first oil phase monomer, and preparing a second oil phase solution by taking at least one of terephthaloyl chloride and 1