Effect of Chitosan on the Performance of Polyamide Thin-Film Nanofiltration Membrane for Desalination

Chitosan-polyamide thin-film composite membranes were prepared to desalinate water via nanofiltrationprocess. The synthesis of these membranes included three stages: ۱- preparation of acrylic ultrafiltrationmembranes, ۲- modification of its surface by interfacial polymerization, and ۳- immersion of membraneinto the chitosan solutions. In order to study the performance, pure water flux, flux and rejection of salinesolutions were measured. In the presence and absence of chitosan, the pure water flux of polyamide thinfilmmembrane obtained ۳۹.۲ and ۴۲.۸ L/h.m۲ at ۴ bar pressure, respectively. These were equal to ۳۲.۴L/h.m۲ for Na۲SO۴ solutions. The results showed that chitosan increases hydrophilicity of polyamideselective layer and therefore chitosan decreases the fouling level. SEM illustrated the excellentestablishment of polyamide layer and chitosan layer on the selective layer.

Keywords:

Chitosan , Desalination , Nanofiltration , Polyamide Composite Membrane