A Mass Balance Model Describing Multiyear Fate of Organochlorine Compounds in a High Arctic Lake
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- 作者：Paul A. Helm ; Miriam L. Diamond ; Ray Semkin ; William M. J. Strachan ; Camilla Teixeira ; and Dennis Gregor
- 刊名：Environmental Science & Technology
- 出版年：2002
- 出版时间：March 1, 2002
- 年：2002
- 卷：36
- 期：5
- 页码：996 - 1003
- 全文大小：127K
- 年卷期：v.36,no.5(March 1, 2002)
- ISSN：1520-5851
文摘
Data collected over a 3-year study of a high arcticwatershed and lake are used to understand the fate oforganochlorine compounds (OCs) and form the basis of amass balance contaminant fate model. The model usesthe fugacity/aquivalence approach to describe OC dynamicsbetween air, stream inflows and outflow, the watercolumn, and surficial sediments. The steady-state modelresults indicate that stream inflows contributed from 96 to>99% of total chemical loadings, but 57-98% of totalloadings were lost from the lake via the outlet, the percentageof which is controlled by the hydrologic regime of thehigh arctic lake. Conversely, only 0.4-3.4% of loadings wereretained within the sediments due to the high exportrate, minimal scavenging from the water column and loworganic carbon fraction of the sediments. Using theunsteady-state model, which includes year-round processes,degradation was estimated to account for losses of7-32% for the more persistent OCs and 42-50% for theless persistent OCs (
fchars/alpha.gif" BORDER=0>-HCH, fchars/gamma.gif" BORDER=0 >-HCH, and endosulfan I). Ifloadings were eliminated, water column concentrations woulddecline with half-lives <1 year for less persistent OCsand 1-2 years for the more persistent OCs, whereas the half-lives for OCs in sediment are 8-25 years.
fchars/alpha.gif" BORDER=0>-HCH, fchars/gamma.gif" BORDER=0 >-HCH, and endosulfan I). Ifloadings were eliminated, water column concentrations woulddecline with half-lives <1 year for less persistent OCsand 1-2 years for the more persistent OCs, whereas the half-lives for OCs in sediment are 8-25 years.