Incorporation of amino-functionalized ZnO nanoparticles into polycarbonate/polyvinyl alcohol thin-film membrane for enhanced water treatment

ZnO nanoparticles were functionalized with amine groups and incorporated into a thin-film nanocomposite (TFN) membrane. Polycarbonate (PC) membranes were coated with polyvinyl alcohol (PVA)/ZnO-NH2 solution using the dip-coating method. All prepared membranes were applied for the removal of humic acid (HA) in a submerged membrane system at vacuum trans-membrane pressure (TMP) of 0.3 and 0.6 bar. Attenuated total reflectance-Fourier transform infrared (ATR-FTIR) and field-emission scanning electron microscopy (FESEM) images confirmed the formation of PVA/ZnO-NH2 top layer on the PC support membrane. The addition of nanoparticles caused the hydrophilicity and surface roughness of TFN membranes to increase. HA filtration experiments revealed that at lower vacuum TMP, the TFN with 0.05 wt.% of ZnO-NH2 nanoparticles showed higher permeate flux. However, at higher vacuum TMP permeate flux significantly decreased. HA rejection did not change with added nanoparticles. As a final result, when vacuum TMP increased from 0.3 to 0.6 bar, rejection of HA slightly increased from 98.3% to 99.1% and 98.3% to 99.3% for thin film composite and TFN with 0.05 wt.% of nanoparticles, respectively.

Automated summary

Functionalized ZnO nanoparticles were incorporated into a thin-film nanocomposite membrane, resulting in increased hydrophilicity and surface roughness, which improved the removal of humic acid.