BEHAVIOR OF MANGANESE IN THE RHINE AND SCHELDT ESTUARIES .1. PHYSICOCHEMICAL ASPECTS

An equilibrium model of the behaviour of manganese during mixing of river- and seawater in estuaries is established on the basis of published thermodynamic data about manganese species in natural waters. The chemical control parameters taken into consideration are: ionic strength, pH, oxygen concentration and total dissolved carbonate content. This model is shown to account for at least the general trends of dissolved manganese variations observed in the Rhine and Scheldt estuaries. Some data about the kinetics of the processes involved in manganese transformations in these two environments suggest that the close approach of the thermodynamic equilibrium is a consequence of the high turbidity and the intense microbiological activity present in these heavily polluted estuaries. © 1979.