Desalination by membrane pervaporation: A review

Pervaporation is a vapor pressure-driven membrane desalination process that can desalinate water with greater total dissolved solids than conventional reverse osmosis. This review analyzes the performance (flux and permeance) of membrane materials used for pervaporation desalination. Poly(vinyl alcohol) (PVA), silica/silicate, graphene oxide (GO), and zeolite were the most frequently used materials to synthesize pervaporation desalination membranes. PVA is the most common material and it yields a relatively high permeance. Surface free energies of different materials were evaluated as well, to analyze the scaling/fouling propensity of the current common pervaporation desalination membranes. PVA is found to be more likely to experience scaling by gypsum while adding organic silica/silicate or GO has the potential to mitigate this issue. When comparing PVA and polyvinylidene fluoride, the hydrophobic polymer is more likely to experience scaling/fouling than hydrophilic polymers. These results indicate that future development in membranes for high-efficiency pervaporation desalination may benefit from emphasizing materials with higher hydrophilicity.