DISPROPORTIONATION AND REDUCTION OF MOLECULAR-IODINE ADDED TO SEAWATER

An oceanic, near-surface seawater sample has been found to sustain the formation of iodate through the disproportionation of the 1.5 mu M ad ded molecular iodine. Some 17% of the added molecular iodine was conve rted to iodate while the remainder was reduced. Even so, a kinetic mod el of the competing reactions, developed specifically for the purpose, shows that the disproportionation reaction will have little geochemic al significance as it is unable to compete effectively at the much low er concentrations of iodine possibly existing naturally in the oceans. The kinetic model is described and its use in the classification of o cean waters according to their ability to reduce added iodine, is disc ussed. The model is probably applicable to the chlorination and ozonat ion of seawater during anti-fouling procedures.