Zur wirtschaftlichen Nutzung saurer Tagebaurestseen sind zur Erarbeitung von Sanierungskonzepten und zu deren Anwendung detaillierte Kenntnisse hinsichtlich Wasserkörper und Sediment notwendig. Die vorliegende Arbeit hat das Bindungsverhalten und die vertikale Verteilung von ausgewählten Elementen (Aluminium, Blei, Cobalt, Eisen, Kupfer, Mangan, Nickel, Zink) im Sediment des sauren Tagebaurestsees 111 (Niederlausitz) zum Gegenstand. Ziel der Untersuchungen war eine Schätzung des vom Sediment ausgehenden Gefährdungspotentials durch die ausgewählten Metalle.

Binding Character of Selected Elements in Acidic Mining Lake Sediments

To investigate the vertical element distribution in an acidic mining lake the concentrations of selected elements were measured by ICP-MS and ICP-OES. By knowing the metal concentrations in different depths it is possible to divide these metals into three groups. While the concentrations of iron, manganese, and zinc decline with decreasing depth, those of aluminium, copper, and nickel rise up. For lead and cobalt no distinct tendency could be determined. The limit value for all measured elements was not exceeded in any sampling location.

The binding character of the metals is, besides the seasonal conditions of the lake (circulation in spring and stagnation in summer), influenced by the sediment depth. The addition of Carbokalk® for lake water neutralization had no significant effect on binding character of the analyzed metals.

The application of a sequential extraction procedure enabled a classification of the available metal binding forms. All analyzed metals occurred mainly in compounds which are difficult to mobilize and for environment only slightly available.