Inside-Out Vs. Outside-in - A Pilot-Scale Evaluation of UF/MF Membranes for Seawater Desalination Pretreatment

摘要

The application of polymeric membranes in seawater desalination pretreatment has become increasingly popular in recent years. Compared to conventional media filtration, membrane pretreatment offers better water quality for the downstream reverse-osmosis (RO) process. In addition, source water conditioning such as coagulation and sedimentation is not required when membrane pretreatment is used, providing the potential benefit of lower chemical consumption than media filtration. The most commonly-used polymeric membranes for seawater RO (SWRO) pretreatment are pressurized ultrafiltration (UF) and microfiltration (MF) membranes with hollow fibers made of polyether sulfone (PES) and polyvinylidene fluoride (PVDF). Inside-out and outside-in membranes, with their respective pros and cons, characterize opposite filtration flow directions. Although abundant research exists on the comparison of UF and MF membranes, little has been done on the comparison of inside-out and outside-in membranes.