Construction of a novel poly(amide-ester) thin film composite hollow fiber nanofiltration membrane with high water permeance

Highly permeable hollow fiber (HF) nanofiltration (NF) membrane is strongly desired since it could achieve efficient desalination with much less energy consumption. In this study, we used 4,4′,4′′-trihydroxytriphenylmethane (TP) as an aqueous co-monomer with piperazine (PIP) to react with trimesoyl chloride (TMC) to prepare a new internally pressurized poly(amide-ester) HF NF membrane. With the incorporation of TP molecules, the synthesized poly(amide-ester) separation layer achieved larger pore size and better hydrophilicity, giving the HF NF membrane excellent water permeance. Under optimum conditions, the HF NF membrane has a water permeance of 151 L m−2 h−1 MPa−1, which is 50 % higher than that of the control HF NF membrane, while maintaining a Na2SO4 rejection of 97.5 %. Moreover, it displays excellent desalination performance towards heavy metal salt solutions and high salinity solutions. It also maintains excellent desalination performance during a long-time filtration experiment, which indicates its good durability performance. In summary, this new poly(amide-ester) HF NF membrane shows good promise for the treatment of heavy metal and high-salinity wastewaters.