Antibacterial polyvinyl alcohol nanofiltration membrane incorporated with Cu(OH)2 nanowires for dye/salt wastewater treatment

In many important industries, such as the textile printing industry, a large amount of dye/salt wastewater is often discharged, which can destroy the ecological environment of the water body. Membrane technology has a great potential in the treatment of environmental problems caused by dye/salt wastewater. Polyvinyl alcohol (PVA) nanofiltration (NF) membrane has a bright future in dye/salt wastewater treatment, however, works on this are rare. Herein, antibacterial PVA NF membrane incorporated with Cu(OH) 2 nanowires for the dye/salt wastewater treatment is reported. The membrane was prepared via coating the solutions containing PVA, glutaraldehyde and Cu(OH) 2 nanowires on the polyethersulfone ultrafiltration membrane. Cu(OH) 2 nanowires has a diameter of 60 nm and was successfully introduced into the membrane. The introduction of nanowires improved the membrane hydrophilicity and roughness, which is conducive to the improvement of membrane flux. Membrane separation performance for one component solution and dye/salt solution were investigated. The introduction of Cu(OH) 2 increases the flux of the membrane obviously (the highest increase is 178.78% (from 21.49 to 38.42 L·m −2 ·h −1 ·bar −1 , for NaCl solution as the feed). Besides, the membrane doped with nanowires also possessed a high dye/salt selectivity. For one component solution, the dye removal rate was over 97.00% while the salt rejection was low (the lowest was 13.18% (NaCl)). For the dye/salt solution, the dye (Congo Red) rejection kept at a high level (98.91%) and the salt (NaCl) rejection was still low (13.71%), while the flux was also high (37.56 L·m −2 ·h −1 ·bar −1 ). The performance is superior to that of many membranes reported in previous works. Moreover, the Cu(OH) 2 nanowires endowed the membrane with an improved and high antibacterial property. The sterilization rate of Escherichia coli and Staphylococcus aureus reached more than 99.99%. • A novel polyvinyl alcohol nanofiltration membrane containing Cu(OH) 2 nanowires was developed. • Cu(OH) 2 nanowires increased the permeance (the largest increase was 177.18%). • The developed membrane showed a high salt/dye separation performance. • The membrane possessed a good antibacterial property.