Qeochemical behaviour of iodine in Jiulong River Estuary

Dissolved iodine species and the relationship between its distribution and salinity in Jiulong River estuarine water have been determined. It has been found that the total iodine, iodate and iodide are positive linear with salinity. This indicates that dissolved iodine species (IO₃^- and I^-) in estuarine water show conservative behaviour. The river water contains 2.40μg/l as iodide and less than 1.0μg/l as iodate, and iodide is the predominant species. Whereas the sea water contains 39.4μg/l as iodate and 4.00μg/l as iodide, and iodate is the dominant form. The distribution of dissolved iodine in pore water, as a function of depth, has been studied. Iodine in pore water occurs as iodide. The apparent fluxes of soluble iodine from the sediment to the overlying water in the estuary have been determined. The values are 2.4 (15℃) and 27μmol/(m²·d) (30℃) respectively.