查看文章

Advances in material science promise the development of a new generation of ultrapermeable membranes (UPMs) for reverse osmosis (RO) desalination and water reclamation, which will lead to reduced footprint and lower capital costs. However, due to the attendant increased concentration-polarization (CP) and membrane fouling effects, the higher fluxes are not possible unless the boundary-layer mass-transfer is enhanced to match the flux increase. In a conventional module, a two-fold increase in flux via UPM would require a four-fold increase in crossflow, generating a 12-fold increase in channel pressure drop. To overcome this, the application of unsteady-state shear to the membrane surface has the potential to be more energy-efficient than a steady-state high shear approach. Hence, this paper reviews a range of unsteady-state shear strategies, including gas sparging, vibrations, particle fluidization, and …