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 per-meance) 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 desali-nation 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.