Microfiltration, ultrafiltration, nanofiltration, reverse osmosis, and forward osmosis

This chapter describes applicable models for microfiltration, ultrafiltration, nanofiltration, reverse osmosis, and forward osmosis. All of these processes are pressure driven, but are very different in terms of modeling, because of the differences in transport mechanisms, rejection of solutes, and fouling phenomena. Models for pressure-driven membrane processes (flux/permeability as well as rejection) can become complex; the approach here is in trying to identify realistic models, on a fundamental or empirical basis, in view of understanding the performance of a membrane from a pragmatic point of view: as an indication for performance indicators, and as a tool to understand the variation of performance as a function of process parameters.