Release of contaminants and nutrients from sediments: exposure and effects
Any component that occurs in pore water of soils or sediments can be studied, since pore water is isolated from the system without disturbing the steady state. This includes nutrients, organic contaminants, and heavy metalsAquatic sediments may absorb or release contaminants from/to surface waters and ground water. The rate and amount of which this occurs is generally difficult to determine. Redox processes (oxidation and reduction) determine the fate of many compounds to a large extent.
SOFIE® has found uses in many types of studies:
- Inundation / flooding experiments;
- Exposure tests with terrestrial and aquatic organisms;
- Bioturbation and contaminant displacement;
- Fluxes of nutrients to/from sediment and surface water;
- Simulation of long-term sediment storage in pitssand pits and lakes;
- (Geo)chemical oxidation and ripening of drained sediments.
Bioaccumulation studies with Tubifex (left) and Chironimus (right) show that uptake is primarily via the free dissolved phase
Redox gradients over water-sedimentgradients occur over short distances.
This affect the bioavailability of compounds.