Electrodialysis Reversal (EDR) Limiting Current Calculator
Compute limiting current density ($i_{lim}/C$), Cowan resistance inflection point, salt flux, and specific electrical energy consumption per $m^3$ treated.
EDR Stack & Feed Characteristics
Current Density & Power Consumption
Recommended Tools & Equipment
Tested hardware and components for high reliability
Electrodialysis Reversal & Limiting Current Theory
Electrodialysis Reversal (EDR) utilizes alternating cation-exchange (CEM) and anion-exchange (AEM) membranes under a DC electric field to transfer ions from diluate channels into concentrate channels. Every 15 to 30 minutes, electrode polarities and flow channels are automatically reversed to dissolve mineral scale without chemical cleaning.
The Cowan-Brown Limiting Current Limit
As current increases, ions migrate out of the diluate channel faster than bulk diffusion can replenish them. At the limiting current density ($i_{lim}$), ion concentration at the membrane surface drops to zero. Operating above this limit forces water molecules to dissociate into $H^+$ and $OH^-$ ions ("water splitting"), causing drastic power waste, localized pH shifts, and catastrophic scaling.