Fig. 9: Comparison of ion migration pathways in symmetric-AEM and conventional FCDI.

Schematic diagrams illustrating the principle of operation and key ion migration pathways. a The symmetric-AEM configuration, which uses two anion-exchange membranes, facilitates anion (arsenate and chloride) transport. b The conventional FCDI configuration uses one anion-exchange membrane and one cation-exchange membrane. c Schematic diagram of equipment operation in SCC mode.