|Dissolved arsenic species in the Schelde estuary and watershed, Belgium|In: Estuarine, Coastal and Shelf Science. Academic Press: London; New York. ISSN 0272-7714, more
arsenic; speciation; estuary; river; model; Schelde
|Authors|| || Top |
- Andreae, M.O.
- Andreae, T.W.
The Schelde watershed drains a densely populated and industrialized region in central Europe. The Zenne River, a tributary which flows through the centre of the Brussels industrial region, contributes most of the arsenic to the river-estuary system. Inputs of industrial and domestic effluents create a region of anoxic conditions in the water column of the upper estuary. A study of arsenic concentrations and speciation in the rivers of the Schelde watershed shows that the ratio of As(III) to As(V) is elevated in the anoxic part of the estuary and those tributaries that are depleted in oxygen.The combination of a near-constant anthropogenic arsenic emission and seasonally fluctuating water discharge creates a variable arsenic concentration in the river endmember. This variability can explain the non-linearity in the arsenic-salinity relationship in the estuary, where a pronounced arsenic maximum is seen in a region without local arsenic sources.The View the MathML source ratio in the estuary has typical marine values in the lower estuary and increases sharply at the oxic/anoxic interface near the head of the estuary. The feasibility of using a numerical model incorporating fluctuating river composition and discharge, tidal mixing, zero-order reduction of arsenate and first-order oxidation of arsenite to model the distribution and redox speciation of arsenic in the estuary under non-steady-state conditions is explored.