Reverse Electrodialysis for energy production from natural river water and seawater

The extent of electrical resistances (ion exchange membrane/electrical double layer/diffusion boundary layer) was elucidated by electrochemical impedance spectroscopy (EIS); in particular, a critical effect of real solution on cation exchange membrane (CEM) resistance was detected. Additionally, ionic characterization of process effluents revealed the occurrence of uphill transport of multivalent ions Mg2+, Ca2+ and SO42−.