A mini-review on pervaporation membrane for desalination

Abstract

Water pollution, which leads to water scarcity, has become one of society's most challenging problems due to the increasing global population and urbanization. Desalination is a helpful strategy for dealing with water scarcity. Nowadays, reverse osmosis is the most common desalination technology. However, it requires energy to overcome osmotic pressures above 500psi. The high energy consumption and other challenges of seawater membrane desalination and strategies to reduce energy were reported elsewhere. Pervaporation (PV) has emerged as the membrane technology for desalinating seawater recently because of its benefits, which include high salt rejection, saving energy, and low fouling phenomena. Accordingly, the PV process can be considered a "green" technology. This study aims to give an overview of research that has employed PV in desalination. This is with an emphasis on PV membrane materials used in desalination and some PV concepts. Overall, the pervaporative desalination process is based on the solution – diffusion mechanism, in which the driving force of the separation process is basically the difference in the partial vapor pressure between the feed and permeate sides divided by the PV selective membrane. Polymer membranes are being studied extensively due to their easy preparation method, low cost, and good salt separation performance compared to organic membranes. To date, the research trend on mixed matrix membranes has gained considerable attention since the unique properties of inorganic fillers, and polymer matrix can be combined to provide resulting membranes with improved salt separation capabilities and stability at higher temperatures. Pervaporation has shown high promise for desalination with adequate productivity and high selectivity. Accordingly, many studies have been conducted in lab and pilot scales to develop the future PV process for commercialization on an industrial scale.