Impact of colloidal organic matter on toxic metal bioavailability in urban water cycle
The role of colloidal organic matter as a key player in the behavior of heavy metals is examined in the urban water cycle. The potential ecotoxicological hazards strongly depend on pollutant speciation and transfer in the environment. Therefore, the present proposal addresses two complementary aspects of the chemical “speciation” – binding of priority metals to urban water colloidal organic matter (UWCOM) and the respective size distribution. On the other hand, bioavailability of the metals bound to UWCOM will be examined. UWCOM generally is not retained by conventional treatment in waste water treatment plants. Metals bound to the UWCOM are expected to have longer residence time in water and may be transported over longer distances; on the other hand following changes in the medium conditions they can aggregate and thus settle down. The present proposal explores the capacity of a hyphenated technique - Flow field flow fractionation –multiangle laser light scattering (MALS) coupled on-line to UV and RI detectors and off-line to ICP-MS to fractionate the UWCOM and their metal complexes according their size. Anodic stripping voltammetry is used to quantify UWCOM binding capacity. Binding of metals by UWCOM will be examined in parallel to bioassays with microorganisms to evaluate metal bioavailability. Urban waters from waste water treatment plants and runoff from urban areas will be studied.
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COST-project within COST action 636: Xenobiotics in the urban water cycle. |
References
Worms I. A. M., Al-Gorani Szigeti Z., Dubascoux S., Lespes G., Traber J., Sigg L., and Slaveykova V. I. (2010) Colloidal organic matter from wastewater treatment plant effluents: characterization and role in metal distribution Water Research 44, 340-350.
Worms I. A. M., Traber J., Kistler D., Sigg L., and Slaveykova V. I. (2010) Uptake of Cd(II) and Pb(II) by microalgae in presence of colloidal organic matter from wastewater treatment plant effluents Environ. Poll. 158, 369-374.