IEX resins of the strong-base anionic type, with quaternary amine functional groups works
slightly better when coupled with carbonatation compared with phosphatation. The reason for
this is that the phosphatation process relies heavily on quaternary ammonium type decolourants,
and they compete with IEX for the same colourants. IEX resins typically deliver colour removal
of 65 – 70 when coupled with phosphatation, and 70 – 75% when coupled with carbonatation.