Variations of chemical forms of iron, manganese and zinc in suspended sediments from the Elbe and Weser rivers during estuarine mixing

Abstract

Distribution of iron, manganese and zinc in the easily and moderately reducible phases of suspended solids (determined by sequential leaching with hydroxylamine hydrochloride and oxalate buffer solutions) was compared with the longitudinal profiles of salinity, pH‐ and E_h‐values in the estuarine mixing zone of the Elbe and Weser Rivers in Northern Germany. The ratios of both fractions (Fe_ERP/_MRP) in the solid species suggest that the removal of dissolved iron during flocculation and precipitation is mainly controlled by the pH‐values, whereas the interactions of manganese and zinc are more affected by the redox conditions in the estuaries.