DOWEX Ion Exchange Resins WATER CONDITIONING MANUAL

Designing an Ion Exchange system
free mineral acidity (FMA). This configuration has advantages in terms of regeneration efficiency and
operating capacity.
With H2SO4 regeneration, two separate cation columns should be used in order to allow acid dilution at
the weak acid resin inlet. For counter-current regeneration, a double compartment, layered bed cation
with a facility for acid dilution at the WAC inlet can be used, but it is more complex to operate. Selected
resins are DOWEX MAC-3 or DOWEX UPCORE MAC-3 for UPCORE systems.
Strong base anion resin type 1: A type 1 strong base anion as a single resin is particularly
recommended for treating low FMA water with high silica and where low silica leakage is required (about
20 ppb in counter-current operation). The resin can be regenerated at up to 122°F (50°C) for more
effective silica removal. DOWEX MARATHON A is designed for general demineralization. DOWEX
UPCORE Mono A500 or DOWEX UPCORE Mono A625 are recommended for UPCORE systems.
Strong base anion resin type 2: A type 2 strong base anion resin is well suited for small plants because
of its excellent regeneration efficiencies for water compositions where CO2 and SiO2 are 100%. Therefore, the efficiency becomes worse as the value increases. Table 23 gives typical
regeneration efficiencies for different resin types and combinations in co-current and counter-current
regeneration systems.
DOWEX Ion Exchange Resins 65 Water Conditioning Manual