|Preparation and characterization of PES/chitosan composite nanofiltration membrane|
|Paper ID : 1358-MST2015-FULL|
zahra afsarian *|
Beheshti Boulevard moalem Boulevard
|A composite membrane was prepared using chitosan (CS) as the active layer supported on a Polyethersulfone (PES) membrane. The chitosan layer was ionically cross linked
with sodiumtripolyphosphate (TPP). The thin layer of chitosan is the reason for the permeability and selectivity of the membrane and the PES substrate served as a mechanical support.
For this purpose, the chitosan thin layer injected into the support membrane under a certain pressure. The membranes were prepared by the combined flow through and surface flow method. The effects of different concentrations (0.1 % and 0.2 % wt) of sodium tripolyphosphate (STPP) salt as the additive were investigated. Characteristics and properties of obtained thin layers were measured by using SEM and filtration set-up. Modified membranes showed higher rejection. Increase in STPP concentration increased the salt rejection of the membrane up to 96.74% for NaCl and 74.85% for Na2SO4 for modified membrane by 0.2 wt% STTP, on one hand with a simultaneous decrease in the flux values, from 9.25 L/m2 h for unmodified membrane to 5.61 L/m2 h for modified membrane by 0.2 wt% STTP. SEM images of cross section of membranes showed a typical asymmetric membrane nature wherein the top layer was dense and a porous sub layer with finger-like projections was formed. Chitosan was deposited as a very thin active layer on the top dense surface of the asymmetric PES membrane and hence it was difficult to distinguish as a separate independent layer in the PES/CS membrane, as well as thicknesses of the skin layers of the treated membranes were enhanced with increasing the STPP concentration.
|nanofiltration membrane- Chitosan- modified membrane - sodiumtripolyphosphate- high rejection|
|Status : Paper Accepted (Poster Presentation)|