Impact of membrane ageing caused by chemical cleaning on the removal of trace organic contaminants by nanofiltration
Fouling is an inevitable phenomenon when using nanofiltration (NF) membranes in water treatment applications which necessitates periodic chemical cleaning to restore the permeate flux. However, harsh cleaning chemicals and conditions (i.e. high cleaning temperature) may accelerate membrane ageing, and cause variation in membrane surface properties and separation efficiency. Indeed, some evidence has emerged that chemical cleaning may lead to considerable variation in the retention of inorganic salts as well as some trace organic contaminants of concern (Simon et al. 2009; Simon et al. 2012).