Preparation and evaluation of heavy metal rejection properties of CS/PES nanofiltration membranes
Paper ID : 1362-MST2015-FULL
Authors:
zahra afsarian *
other
Abstract:
This work studied modification of hydrophobic membrane by chitosan (CS) solution for heavy metal removal. Accordingly, the nano-porous membrane was prepared by depositing a thin layer of chitosan on an ultrafiltration support. Therefore, the polyethersulfone (PES) support membrane was made, and then chitosan solution was coated on the support membrane surface. Chitosan solution concentration was varied (0.5 and 1.5 wt%). The prepared membranes were evaluated by SEM, contact angles and filtration set-up. The results of scanning electron microscopy (SEM) and contact angle study of modified membranes compared to unmodified membrane confirmed that there was chitosan coated on the membranes surface. The water contact angles and water fluxes decreased with increasing chitosan concentration. Pure water flux was reduced from 36.73 L/m2h for the unmodified membrane to 3.69 L/m2h for the modified membrane by 1.5 wt% CS. The rejection of membranes towards the copper and chromium ions was studied during filtration. A maximum of 72.64% of Cu and 56.47% of Cr rejection for modified membrane by 1.5 wt% CS, with reasonably good flux was observed. The SEM images showed a smooth surface for the unmodified membrane and a dense and compact thin layer on the support membrane surface for modified membrane. The result also indicated that modified membranes had higher hydrophilicity than unmodified membrane. The hydrophilicity of the membranes increased with chitosan concentration due to the increased amount of chitosan deposit.
Keywords:
nano-porous membrane - modified membranes - polyethersulfone (PES) support - thin layer
Status : Paper Accepted (Poster Presentation)