This work focuses on the elucidation of various underlying mechanisms responsible for the flux reduction in PRO processes.

Both inner- and outer-selective TFC hollow fiber membranes are employed to examine how the fundamental internal factors interact with one another, resulting in various behaviors of external performance indexes such as water flux, reverse salt flux, and power density.

The insights obtained from the stationary conditions are combined with the advanced nucleation theory to elucidate the dynamic scaling process by visualizing how the multiple fundamental factors evolve and interplay with one another during the whole scaling process.

This study may provide useful insights to design more suitable TFC hollow fiber membranes and to operate them with enhanced water flux so that the PRO process may become more promising in the near future.