An electrodialysis stack is to be used to partially demineralize 100,000gal/day of advanced treated wastewater so that it can be used for reuse by an industry. the membranes are 30 x 30in., and the salt concentration is 4500mg/L. the cations and anions are 0.0742mg/l. the pertinent data are as follows: stack resistance = 4.5 ohms, current efficiency = 90%, ratio of maximum current density to normality = 400 ( with current density as ma/cm2), power cost 2.5cents/kw-hr, brine density = 67lb/ft3, and brine = 12% salt.
determine: number of membranes, the product water and brine flows, gal/day