SS3.04 Biogeochemistry of DOC/DON in a Watershed Context
Date: Wednesday, June 12, 2002
Location: Poster Session - VCC
 
HumphriesSA, University of Waterloo/Department of Earth Sciences, Waterloo, Canada, sahumphr@sciborg.uwaterloo.ca
Schiff, S, L, University of Waterloo/Department of Earth Sciences, Waterloo, Canada, sschiff@sciborg.uwaterloo.ca
Wu, F, C, Trent University/Environmental & Resource Studies, Peterbrough, Canada, fwu@trentu.ca
Elgood, R, J, University of Waterloo/Department of Earth Sciences, Waterloo, Canada, rjelgood@sciborg.uwaterloo.ca
 
DOM AND METAL BINDING: NEW TECHNIQUES FOR DETERMINING %S, 34S/32S and 18O/16O IN DOM
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Dissolved organic matter (DOM) is known to complex potentially toxic metals in natural aquatic systems. DOM-metal complexation affects both the speciation and mobility of metals, and in turn affects the metal's fate, transport, and toxicity to aquatic life. Organic sulfur functional groups have been suggested as important metal binding sites due to the availability of lone pair electrons on reduced sulfur. We are currently developing new techniques to determine %S, 34S/32S and 18O/16O in total DOM. The %S in DOM will provide clues on metal binding, 34S/32S will provide information on the origin and diagenesis of S in DOM, and 18O/16O should yield insight into the autochthonous or allochthonous origin of the DOM. Samples of precipitation, throughfall, soilwater, groundwater, streams and lakes have been isolated from Precambrian shield watersheds near Dorset, Ontario, Canada. Results from these new techniques will be compared to estimates of metal binding capacity of DOM.