The research concerns the biogeochemical cycles of trace elements in natural waters, in particular the speciation of trace metals, which are strongly affected by anthropogenic inputs, and the interactions of trace metals with aquatic organisms. The following topics have been studied in the last few years:
Speciation of trace elements in lakes, rivers and groundwater: Binding of trace metals (copper, zinc, cadmium, nickel, cobalt) to organic ligands in natural waters has been examined using mostly ligand-exchange coupled to voltammetric methods. The extent of complexation of these elements has been evaluated in various aquatic environments. Occurrence of strong ligands has been demonstrated in various types of freshwater.
Speciation and mobility of trace elements in groundwater and soil drainage water: The role of natural organic ligands in groundwater has been examined with respect to adsorption reactions of trace elements. Speciation and mobility of trace metals in drainage water from agricultural soils has been studied.
Speciation and bioavailability of trace elements to aquatic organisms The role of speciation of trace elements (copper, zinc, cadmium) for uptake by algae and periphyton in freshwater is studied in laboratory and field experiments in collaboration with ecotoxicologists. Intracellular ligands in algae (phytochelatins) are being examined with respect to tolerance mechanisms to toxic metals. Within an European collaborative project various speciation methods are compared and studied with regard to their potential for predicting uptake of trace metals by algae.