Removal of trivalent metal ions from aqueous solution via cross-flow ultrafiltration system using zeolite membranes

摘要

This study aimed to assess the performance of three zeolitemembranes in the removal of trivalentmetal ions from aqueous solution using a cross-flow mode of operation. Three types of zeolite membrane, MCM-41, MCM-48 and FAU, were prepared on a low-cost, circular ceramic support by hydrothermal treatment. The three zeolite membranes were characterized by using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and contact angle measurements. The XRD results confirmed the formation of zeolites. The deposition of zeolite on the ceramic support and hydrophilicity of zeolite membranes were monitored by FESEM and contact angle measurement, respectively. The pore size of the MCM-41, MCM-48 and FAU membrane was found to be 0.173 mu m, 0.142 mu m, and 0.153 mu m, respectively, which was lower than that of the support (1.0 mu m). The fabricated zeolite membraneswere used to investigate the separation behavior of trivalent metal ions (Al-3 and Fe-3 ) from aqueous solution at various applied pressures. Itwas observed that an increase of applied pressure leads to a slight decrease in the removal efficiency. Among the various zeolitemembranes, the FAUmembrane showed the maximum rejection of 88% and 83% for Fe-3 and Al-3 separation, respectively.