Uptake of Iodine and Bromine by Ion-Exchange Resins in Aqueous Solution

Abstract

The uptakes of molecular iodine and bromine by both strong acid cation (Dowex 50W-X4 and X8) and strong base anion (Dowex 1-X4 and X8) exchange resins have been studied in aqueous solutions at 25°C. An empirical formula for the amount of solute taken up by the resin in mmol per gram of dry resin, Q, as a function of the solute concentration in M (mol dm^-3), C, was derived. Direct proportional relationships between Q and C have been found, except for the bromine-anion exchanger system. In contrast to the cation-exchange resin, the anion exchanger exhibits extremely high affinity for I₂ and Br₂.