Lewatit® TP 207 is a mildly acidic macroporous cation exchange resin with iminodiacetic acid groups for the selective attachment of heavy metal cations from weakly acidic to weakly basic solutions Divalent cations are removed from neutralized waters in the following order: Copper> Vanadium (V02 ')> Uranium (U0221> Lead> Nickel> Zinc> Cadmium> Iron (II)> Beryllium> Manganese> Calcium> Magnesium> Strontium> Barium >>> Sodium.