Ion exchange resin types | ||||||||||||||||||||||||||||||||
Srongly Acidic Cation Exchange Resins
|
| Functional groups | —SO3– H+ Sulphonic acid |
| What they do | In sodium form, they remove hardness (essentially calcium and magnesium) from water and other solutions
In hydrogen form, they remove all cations They are also used as acidic catalysts |
| Examples | AmberjetTM 1000 Na
DowexTM Marathon C LewatitTM Monoplus S100 |
| Typical total capacity | 1.9 to 2.2 eq/L [Na+] |
Weakly Acidic Cation Exchange Resins
(WAC)
| Functional groups | —COOH Carboxylic acid |
| What they do | In hydrogen form, they remove preferentially divalent ions (e.g. calcium and magnesium) from solutions containing alkalinity |
| Examples | AmberliteTM IRC86
DowexTM MAC3 LewatitTM CNP80 |
| Typical total capacity | 3.7 to 4.5 eq/L [H+] |
Strongly Basic Anion Exchange Resins
(SBA)
| Functional groups | —N(CH3)3+ OH– Quaternary ammonium |
| What they do | In hydroxyl form, they remove all anions
In chloride form, they remove nitrate, sulphate and several other ions |
| Examples | AmberjetTM 4200 Cl
DowexTM Marathon A LewatitTM Monoplus M500 |
| Typical total capacity | 1.0 to 1.5 eq/L [Cl–] |
Weakly Basic Anion Exchange Resins
(WBA)
| Functional groups | —N(CH3)2 Amines |
| What they do | After cation exchange, they remove chloride, sulphate, nitrate, and other anions of strong acids, but they do not remove weak acids (SiO2 and CO2) |
| Examples | AmberliteTM IRA96
DowexTM Marathon MWA LewatitTM Monoplus MP64 |
| Typical total capacity | 1.1 to 1.7 eq/L [free base] |
Selective and chelating resins
| Functional groups | Many different types | ||||||||||||||||||||||||
| What they do | They remove metals, boric acid, perchlorate or other ions selectively | ||||||||||||||||||||||||
| Examples |
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| See details in | Resin structure. |
Further reading:
- Laboratory photographs of various resins.
- Structure of the matrix and functional groups of ion exchange resins.
- Resin properties
- Selectivity tables for cation and anion exchange resins.
- Ion exchange capacity
Amberjet, Amberlite, Ambersep, and Dowex are trademarks of the Dow Chemical Company.
Lewatit is a trademark of Lanxess.
