Current distribution along electrodialysis stacks and its influence on the current-voltage curve: behaviour from near-zero current to limiting plateau

The current maldistribution along the flow path of electrodialysis (ED) units is a well-known phenomenon. However, it has been poorly quantified via experimental tests so far. This work aimed at measuring distribution in an ED stack with 40 cm length, provided four-segment electrodes. current-voltage curve (CVC) each segment was recorded under several operating conditions inlet concentrations and feed velocity. In CVC first segment, increased approaching saturation, while that remaining segments passed through maximum then settled near-zero values when high voltage were applied. fraction on decreased from to outlet. overall CVC's region, up ~50 % total flowed quarter stack. As increased, other ones tending vanish. At limiting condition, relative standard deviation ranged 68 %. strong non-uniformity stack, which may represent one stage industrial plant, implies design commercial must be improved.