Modified heterogeneous anion-exchange membranes for desalination of brackish and recycled water Academic Article uri icon

abstract

  • In the desalination of recycled water, the triple demand for a high recovery ratio, low energy consumption, and fouling resistance can be met by electrodialysis (ED) under certain conditions: high recovery is an inherent property of the process, while low energy consumption and fouling resistance can be obtained by the use of modified heterogeneous membranes. To this end, heterogeneous polyethylene-based anionexchange membranes were modified by a hydrophilic anion-exchange coating, having an ion-exchange capacity of 2.2 to 2.9 mEq/g (dry weight) and a specific conductance of 70 to 110 mS/cm. The coating was found to be stable in continuous ED operation (66 days). The modification suppressed water splitting and brought the performance of the coated heterogeneous membranes into line with that of homogeneous commercial anion-exchange membranes. Direct measurement of the polarization at the coated membranes indicated that this phenomenon decreased as a result of the coating. Mathematical modeling showed that ...

publication date

  • November 1, 2002