Comparison of chemical cleaning reagents and characterization of foulants of nanofiltration membranes used in surface water treatment

Fouling continues to be an important limitation in membrane operation for water treatment. In this work, we compare various chemical agents with respect to their ability to remove fouling as well as their potential to deteriorate membrane rejection or the physical properties of the membrane. Contact angle of the membrane surface appears to be a good indicator of the efficiency of the membrane cleaning in parallel with results of the total organic carbon and the metal presence. The specific ultraviolet absorbance (SUVA) is also shown to be a useful parameter for monitoring the efficiency of cleaning, that can easily be implemented in-line on a full-scale facility.

► The change in contact angle is a good indicator of cleaning efficiency.
► SUVA is a fast and good indicator of the cleaning efficiency.
► NaOCl is the best cleaning agent but can have detrimental effect on the membrane.