Abstract

Nanofiltration (NF) has received increased attention as a possible treatment
process providing high rejection of solutes and high water flux rate. Using NF as a
desalination process for Iraqi surface water is considered in this research. A small
system with one membrane of 4 inch diameter and 1 meter long was used to
evaluate the performance of NF membrane for the desalination of Tigris River
water in Baghdad, and compare it with a reverse osmosis (RO) membrane. The
results showed that one could get double the permeate flow rate and spend about
20% less electric power when using NF membranes instead of RO membranes.
Permeated water TDS values for NF membrane are low enough to allow for further
adjustment for drinking water quality. NF rejection capacity for monovalent ions is
lower than that of the divalent ions, and in general the salt rejection capacity is
above 88%.