Example of strong base anion exchange resin
Will remove All Anions from water
Strong Base Anion Exchange Resins can be categorized as Type I or Type II depending on the nature of the functional groups / type of amine used during the chemical activation process.
Type I - Quaternary Ammonium Functional Group. Chemically it has three methyl groups. - Functional group with the highest basicity amongst commonly used anion resins. - Used when very low silica levels are desired (< 0.2 ppm) - Requires excess of regenerant than type II SBA resins
Quaternary Ammonium Functional Group. Chemically one of the methyl groups of type-I is replaced with ethanol group.
Less Basic Functional Group as compared to Type I
Higher Silica Leakage Compared to Type I (< 0.5 ppm) Easier to Regenerate.
Example of weak base anion exchange resin
Tertiary Amine Functional Group.
Much Lower basicity compared to SBA
Will remove anions associated with free mineral acidity (e.g. CI, sulfate from solution of respective mineral acids).
Cannot remove anions associated with weak acids (carbonic, silicic acids).
Can be regenerated with stoichiometric quantities of regenerant.