Various Cleaning Agents for a Nanofiltration Membrane Are Investigated

Various cleaning agents for a nanofiltration membrane are investigated. Methods for assessing the efficiency of a given cleaning procedure are evaluated from the perspective of changes in the appearance of the membrane surface, the mass removed, and the ultimate impact on restoring permeate flux. Fouling continues to be an important limitation in membrane operation for the treatment of surface water. Thus an understanding of the characteristics of membrane foulants is essential for optimisation of a chemical cleaning scheme, as well as the interaction between the membrane and the foulants. In this US-Australian-French work, various chemical agents are compared with respect to their ability to remove fouling in batch tests, as well as their potential to reduce membrane rejection or the physical properties of the membrane. The 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, which can easily be implemented in-line on a full-scale facility. Source:workingwithwater.filtsep.com