Dissolved phase speciation of zinc in the humber estuary

An established approach to the determination of zinc speciation in natural waters has been applied to samples from a major UK estuary. Data for dissolved zinc concentrations and zinc complexation capacity are reported. The importance of the strength of the metal-ligand complex to the estimation of the predominant forms of zinc in estuaries is discussed. Dissolved zinc in the two major river inputs and low salinity zones appears to be more or less exclusively associated with naturally-occurring organic complexing material. At higher salinities, the assessment of predominant zinc species is dependent on uncertainties in estimates of the metal ligand stability constant.