ISSN:
1573-5117
Keywords:
Sediment transport tracers
;
Great Lakes
;
organic components
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract Bottom sediments around the outfall of the Humber Sewage Treatment Plant (STP), which, with the Humber River, comprises the major contaminant point source emptying into Humber Bay, Lake Ontario, were analyzed for a number of cultural and industrial organic contaminants, including sewage-related compounds such as the faecal sterol coprostanol, α-tocopheryl acetate (α-TA), linear-chain n-alkane hydrocarbons, and carbon and nitrogen isotope ratios of refractory sediment organic matter. The goal was to test these chemical markers as tracers of contaminated fine sediment transport. Although these chemical species are not all conservative (some decompose at fairly rapid rates), they are believed to be good ‘natural’ tags for fine sediment and should nonetheless exhibit clear dispersal plumes from a presumed source. Their plumes can thus provide an effective way to obtain qualitative, intermediate- and long-term transport pathway indicators for contaminated sediments discharged on a continuing basis. The contoured plots for coprostanol, alpha-tocopheryl acetate, and n-alkane distribution were characterized by high values near the STP outfall, and these tracers were detectable at distances of 1 km or more. Interpretation of the net transport patterns indicates a primary transport toward the south and southwest, with a secondary trend northward, curving eastward. The carbon and nitrogen ratios, while showing a slightly different pattern, served to differentiate STP-source materials from those coming from the river and the open lake. Thus, transport from these sources, sometimes in the opposite direction to that from the main source, were resolved. Systematic variations in the interpreted transport patterns are explained by the presence of different pathways taken by the sediments, i.e. whether bedload or suspended load in a stratified water column.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00026202
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