Pervaporation characteristics and solution-diffusion behaviors through sodium alginate dense membrane

A sodium alginate dense membrane was prepared for water-selective separation by pervaporation (PV). In this study, alcohols and other organic liquids such as THF, 1,4-dioxane, and acetone were dehydrated through a membrane made of this polyelectrolyte. By changing the operating conditions, including feed concentration and temperature, the PV characteristics were investigated in detail. The results demonstrate that sodium alginate was an exceptional membrane material with large values of both flux and selectivity. Furthermore, the pervaporation mechanism was elucidated by making an investigation into the solution–diffusion behaviors of penetrants. It was found that the solution process makes much more of a contribution on permselectivity than does the diffusion step.