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Piperazine-fluoropolyamide nanofiltration (NF) membranes were prepared by interracial polymerization of PIP and BHTTM mixture with TMC.The results showed piperazine-fluoropolyamide NF membrane prepared under the optimum conditions exhibited pure water flux (PWF) withl3.2 LMHBAR and Na2SO4 rejection of 99.5% under 6 bar.The best NF membrane had a molecular weight cut-off (MWCO) less than 300 Da,corresponding to the pore size of 1 nm, which was calculated from the rejection of carbohydrates.Through the NaClO pre-oxidation of the mixed diamine monomers of PIP and BHTTM in the aqueous phase solution, the active layer of NF membrane became thinner and the pore size of NF membrane was enlarged.Besides, after oxidation treatment by 3000 ppm active chlorine solution for 1 hour, the NF membrane exhibited pure water flux with 26.8 LMHBAR and Na2SO4 rejection of 92.1% under 6 bar.The molecular weight cut-off (MWCO) of the NF membrane was greater than 500, which was calculated from the carbohydrates rejection.Formation conditions of the selective polyamide layers of TFC hollow fiber NF membranes have been optimized for a good NF membrane performance, ie,the pure water flux of NF membrane was 5.2 LMHBAR and the rejection for Na2SO4 was 99.7% at 6 bar.The molecular weight cut-off of NF membrane was around 300 Da.The performance of NF membranes was stable during a 7-day filtration process for rejecting different species ions including heavy metal ferric ion (FeCl3 and Fe2 (SO4)3) and oxyanions (SO42-and HPO42-), in addition to different inorganic salts.PES three-channel capillary NF membrane displays pure water flux of 9.0 LMHBAR and Na2SO4 rejection of 96.8% at 4 bar.The pure water flux and Na2SO4 rejection of the NF membrane after 5 000 ppm-h NaClO immersion was 10.9 LMHBAR and 99.8% at 4 bar, respectively.The fabricated membrane can tolerant 13 000 ppm-h Cl under 4 bar, and the water flux and Na2SO4 rejection of the NF membrane are maintain at 12.9 LMHBAR and 99.6% during the NF running process, respectively.Moreover, the prepared membrane exhibits 3.84 × 105 ppm-h chlorine-tolerant at 0 bar during the NF running process.These results indicate that the prepared PES three-channel capillary NF membrane could be applied to the practical process of desalination or water softening.