Hydrophilic hollow fiber membranes for water desalination by the pervaporation method

Hydrophilic ion-exchange membranes based on sulfonated polyethylene hollow fibers were manufactured, and their suitability for a water pervaporation process was studied for possible application in water desalination systems. The effects of the following parameters on the average water flux were determined: membrane properties (diameter (0.4-1.8 mm) and wall thickness (0.05-0.18 mm)); charge density (0.6-1.2 meq g−1); and operating conditions (brine inlet temperature (30-68°C), air sweep velocity (0-6 m s−1), and salt concentration in the feed brine (0-3 M)). A water flux of 0.8-3.3 kg m−2 h−1 was obtained using this type of hollow fiber with an inlet brine temperature of 25-65°C. It was found that, for our application, the optimal specifications for the ion-exchange hollow fibers were an outside diameter of 1.2 mm, a wall thickness of 0.1 mm, and an ion-charge density of about 1.0 meq g−1. This information is required as basic data for the design of a prototype water desalination system based on a pervaporation system that uses this type of ion-exchange hollow fiber membrane