Membranes - Principles of Chemical Separations with Environmental Applications - page 273

(a) Provide a preliminary design of a system to produce 90% removal of Ni.
(b) Determine the number of membranes,
(c) power required, and
(d) the annual electrical cost @ $0.05/kWh.
Hint : You can use the following equation to find the number of cells:

I = ( FQN / n ) × ( E 1 / E 2 ) ,

where I = current (amps)

F = Faraday' constant = 96,487 coulombs / g-equivalent (or amp · s / g-equivalent)

Q = flowrate (L / s) [gal / min × 0.06308 = L / s]

N = normality of solution (g-equivalents / L)

n = number of cells between electrodes

E 1 = removal efficiency (fraction)

E 2 = current efficiency (fraction)