Tongji University

Tianjin Polytechnic University

Ruobin Dai

Zhiwei Wang

Tianlin Wang

Liang Wang

Hongwei Zhang

Hongyi Han

Chenxin Tian

Mei Chen

Xueye Wang

Zhichao Wu

Qiaoying Wang

Huimin Zhou

Jiayi Li

Jiansuxuan Chen

Provided is a high permeance nanofiltration membrane with nanoring-like structure and preparation method thereof. The membrane includes a base film and a polyamide layer having nanoring-like structure morphology on its surface. The method includes: (1) formulating a piperazine nanoemulsion containing a surfactant, vegetable oil, piperazine and water; and (2) infiltrating a base film with the piperazine nanoemulsion, and removing excess droplets from the surface of the base film to obtain a treated base film; covering the surface of the treated base film with a solution of trimesoyl chloride in n-hexane to perform interfacial polymerization; and drying the resulting membrane. Introduction of nano-oil droplets into aqueous phase as templates to construct nanoring-like structure morphology on the surface of the polyamide layer significantly increases the specific surface area and free volume of the polyamide layer without losing the salt rejection rate of the membrane, thereby greatly improving its water permeance.

High permeance nanofiltration membrane with nanoring-like structure and preparation method thereof

A method for recycling a scrapped polyvinylidene fluoride (PVDF) membrane through chemical cleaning-structural transformation-hydrophilicity is disclosed, which can extend the service life of scrapped PVDF membrane materials (namely, membrane at the end of service life). The method includes the following steps: cleaning a scrapped membrane with sodium hypochlorite and citric acid; treating the membrane with a structural transformation agent, where, irreversible contaminants are washed away while the PVDF membrane is subjected to pore expansion and hydrophilization; and with self-polymerization of dopamine on a membrane surface, further improving the hydrophilicity of the membrane surface, enhancing the anti-contamination performance, and repairing damaged points on the surface of the scrapped PVDF membrane produced during long-term operation.

Method for recycling scrapped polyvinylidene fluoride (PVDF) membrane produced in water treatment

A device for decomplexation and enhanced removal of copper based on self-induced Fenton-like reaction constructed by electrochemistry coupled with membrane separation is disclosed. The device includes a reactor, two electrocatalytic anodes capable of generating hydroxyl radicals, an electrocatalytic cathode membrane assembly, a direct current power supply, an aeration system, an inlet pipe and an outlet pipe. The device of the present invention has a simple construction. Using this device to treat industrial wastewater containing copper complexes under specific conditions allows the decomplexation and the removal of the industrial wastewater containing the copper complexes to be simultaneously realized at a low consumption and a high efficiency. The coupling of electrochemistry with membrane separation can be achieved to protect the cathode from being contaminated by pollutants in the sewage and prolong the service life of the electrode.

Device for decomplexation and enhanced removal of copper based on self-induced fenton-like reaction constructed by electrochemistry coupled with membrane separation, and use thereof

A polyamide (PA) nanofiltration (NF) membrane and a preparation method thereof by regeneration from a scrapped microfiltration (MF) membrane are provided. The method adopts a cleaning-repairing-interfacial polymerization upgrading strategy, where, sodium hypochlorite and oxalic acid are used for deeply cleaning a scrapped MF membrane. PDA is used as a repairing agent to construct a reaction platform on the membrane surface, and finally a reaction system of piperazine and trimesoyl chloride (TMC) are used to form a PA NF membrane with a PA active layer. The repairing can construct a coating with a given thickness and prominent hydrophilicity on the membrane surface, which provides favorable base membrane conditions for upgrading and preparing an NF membrane.

Polyamide (PA) nanofiltration (NF) membrane, and preparation method thereof by regeneration from scrapped microfiltration (MF) membrane

A nanofiltration membrane with a high flux for selectively removing hydrophobic endocrine disrupting chemicals and a preparation method thereof are provided. The method includes the following steps: immersing a porous support layer into a first solution, removing excess droplets from a surface of the support layer after taking the support layer out of the first solution, and then immersing the support layer attached with the first solution into a second solution for an interfacial polymerization reaction, followed by washing after completion of the reaction to obtain the subject nanofiltration membrane. The first solution is an aqueous solution containing a polyamine monomer and an acid binding agent, and the second solution is an organic solution containing an acid chloride monomer and a metal-organic framework.

Nanofiltration membrane with high flux for selectively removing hydrophobic endocrine disrupting chemicals and preparation method thereof

A high-performance thin-film composite polyamide membrane upcycled from a substrate fouled with a biopolymer and a preparation method thereof are provided. The method includes fouling the substrate preferably with the biopolymer to obtain a composite of the substrate and a biopolymer foulant layer; then immersing the composite into a first solution formed by dissolving a polyamine monomer in water, followed by taking the composite out of the first solution and removing excess droplets from a surface of the composite; then immersing the composite treated in the previous step into a second solution formed by dissolving an acyl chloride monomer in n-hexane for interfacial polymerization to form a rejection layer on the surface of the composite; and after completion of the reaction, taking the composite out of the second solution, followed by drying and heat treatment, to obtain the target polyamide membrane.

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Shanghai, China

Ruobin Dai