Exchange of solutes between sediment and water

Sediments act as sources and sinks for many compounds and elements. Trace metals and organic contaminants have a high particle affinity and can be absorbed or released by sediments; a large fraction of the elements that take part in the biological cycles (C, N, P) are mineralized in the sediment, and carbon dioxide, nitrate, and phosphate are released to the water column. Therefore, the study of fluxes between sediment and water column is important for the understanding of contaminant concentrations and eutrification levels. Solute fluxes can be studied in the laboratory bij confining a sediment sample and a volume of overlying water in a microcosm. Since the hydrodynamical conditions at the sediment water interface determine the solute exchange flux, the hydrodynamical calibration of microcosms is important. In this thesis a microcosm with calibrated hydrodynamics is evaluated. Measurements of oxygen fluxes to the sediment, and organix contaminant fluxes from the sediment are discussed. ... Zie: Summary.