To identify membrane fouling, here are some key parameters to consider:

1.The most important is to compare the difference in membrane flux (in units such as LMH or LPM) under the same operating conditions (same pressure, temperature, cross-flow velocity). Typically, if the flux of an old membrane drops below 85% of the flux of a new membrane, it is considered fouled;

2.Membrane fouling usually leads to changes in membrane retention performance — this change can either increase or decrease;

3.Under the same operating conditions, after membrane fouling, the pressure difference across the membrane module increases, meaning the membrane resistance becomes greater.