From Standard Systems
The matrix shown in the above equation represents a polymeric bead structure to immobilise the functional sulfonic acid groups. Both examples below show the blue pressure vessels which are filled with the ionexchange media. A regeneration salt reservoir (white) provides NaCl to recharge the media once the sodium has been depleted.
Softening systems remove water hardness by way of exchanging dissolved calcium and magnesium ions in water against matrix-bound sodium ions:
Matrix - (SO3Na)2 + Ca2+ = Matrix - (SO3)2Ca + 2 Na+