Immobilisierung von Schwermetallen in Baggerschlämmen

[siehe engl. Summary]Disposal alternatives for contaminated dredged materials from Hamburg harbor were discussed with respect to the mobility of heavy metals. Oxidation of sulfide minerals and organic substances, partly mediated by bacteria, affects mobilization of critical trace elements such as cadmium both in terrestrial and aquatic environments. Disposal of reduced sludge in estuaries should be avoided as well as areal dispersal of contaminated sediments in shallow marine areas. Chemical stabilization of these waste materials can be achieved by addition of calcium carbonate (land disposal of less buffered sludges) or by storage under permanently anoxic conditions out of the range of productive zones, e.g. in near-coast sub-sediment deposits