regeneration of permutit is done by
Hi,
The exhausted permutit is regenerated by treating sodium hydroxide solution in Clark's method for removing permanent hardness .
CaZ+2NaCl -> Na2Z+CaCl2
Exhausted permutit means the impurity in water i.e Calcium (Ca) that is replaced by Na due to which it becomes Ca2Al2Si2O8.xH2O. It is regenerated by 10% NaCl solution (brine solution). It is most efficient method to get water with zero degree of hardness.
Hope this helps.