Fouling Potential in Pressure Driven Membrane Processes

Fouling potential is an important factor to consider when selecting a membrane for any given separation process. Membrane fouling can easily be examined through monitoring permeate flux [of a compacted membrane], with both pressure and temperature held constant. This is due to the inverse relationship between flux and total resistance, as the latter increases as fouling progresses. An optimal membrane would show minimal flux decline as time goes on. However, a drastic and rapid flux decline would indicate that the membrane is highly prone to fouling with that particular feed stream. However there are other methods availablefor determining fouling tendencies, such as via the silt density index or plugging index, which are used to examine the feed stream for fouling potential rather than the membrane.