GE E4H-CE Series - Manual (Page 8)

C
f
= Feed Concentration
C
p
= Permeate Concentration
C
c
= Concentrate Concentration
C
avg
= Average Concentration in Machine
1.1.10 Salt (Ionic) Passage
Ionic Salt Passage equals the percent of dissolved salts passed through the mem-
brane element or 100% minus rejection.
1.1.11 Recovery
Recovery equals permeate rate divided by feed rate and is expressed as a per-
centage. For example, 75% recovery means that out of a given feed rate, 75% is
produced as purified water (permeate).
1.1.12 Salt (Ionic) Rejection
Ionic Salt Rejection equals the percent of dissolved salt rejected by the membrane
element, calculated from an average concentration over the membrane element.
An example of how to calculate salt rejection and recovery is below:
Figure 1.3
Principles of Operation
Given the system case in Figure 1.3:
3
Average Concentration (C
avg
) = [(C
f
) + (C
c
)]
2
= [(100 mg/L) + (375 mg/L)]
2
= 237.5 mg/L