OPERATORS MANUAL
ORION II
Orion II 500-10000 Operators
Page 91 of 95
Manual Part no: DOMAON0100 Issue A
April 2008
9.2.3 How the CEDI system works
1. Feed water entering the system flows into resin/membrane compartments. The feed stream flows
parallel to the membrane surface.
2. Resins capture dissolved ions.
3. Electric potential drives captured cations through the cation membranes and captured anions
through the anion membranes.
4. Cation permeable membranes transport cations, such as sodium (Na
+
) ions, out of the diluting
compartment, but prevent anions from leaving concentrating compartment.
5. Anion permeable membranes transport anions, such as chloride (Cl
-
) ions, out of the diluting
compartment, but prevent cations from leaving concentrating compartment.
6. Waste stream removes concentrated ions from system.
Product Water
H
2
O
(7)
Waste
Stream
(NaCl)
conc
(6)
(5)
(4)
(2)
(3)
(3)
Feed Water
NaCl
(1)
Cl
Na
H
OH
Na
Cl
(+)
(-)
