Resins with primary or secondary amino groups as functional groups are weakly basic and are called weakly basic anion exchange resins. Weakly basic anion exchange resins have weak bases and do not dissociate in alkaline solutions and do not have ion exchange capacity. Therefore, neutral anions such as NaCl and Na2SO4 cannot be exchanged, but with mineral acids such as HCl and H2SO4 and weak base salts such as NH4Cl are Ion exchange can be performed.

In addition, weak acids are generally difficult to capture, and some resins can exchange H2CO3 , but silicic acid (silica) is not exchanged.In this way, these resins are easy to be regenerated due to its weak basicity, and it can be regenerated using Na2CO3 or NH3 as well as NaOH . The regeneration level is slightly higher than the theoretical chemical equivalent, and it is economical