High-performance thin-film composite polyamide membrane upcylcled from biopolymer-fouled substrates and preparation method thereof

A method for preparing a thin-film composite polyamide membrane upcycled from a substrate fouled with a biopolymer, comprising the following steps:

• (1) fouling a microfiltration membrane substrate or ultrafiltration membrane substrate with the biopolymer, which is a protein, a humic acid, or an extracellular polymeric substance, to obtain a composite of the microfiltration membrane substrate or ultrafiltration membrane substrate having a biopolymer foulant layer on a surface of the microfiltration membrane substrate or ultrafiltration membrane substrate;
• (2) dissolving a polyamine monomer in water to form a first solution, and then immersing the composite obtained in step (1) into the first solution, followed by taking the composite out of the first solution and removing excess droplets from a surface of the composite;
• wherein the polyamine monomer is at least one selected from the group consisting of piperazine, m-phenylenediamine, and p-phenylenediamine, and the first solution contains the polyamine monomer at a mass concentration of 0.05%-1.0%;
• and
• (3) dissolving an acyl chloride monomer in n-hexane to form a second solution, then immersing the composite treated in step (2) into the second solution for an interfacial polymerization reaction to form a polyamide rejection layer on a surface of the biopolymer foulant layer of the composite, and after completion of the interfacial polymerization reaction, taking the composite out of the second solution, followed by drying the composite and performing a heat treatment on the composite, to obtain the high-performance thin-film composite polyamide membrane.