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Title: How the K{sub d} approach undermines ground water cleanup

Abstract

Environmental scientists have long appreciated that the distribution coefficient (the K{sub d} or constant K{sub d}) approach predicts the partitioning of heavy metals between sediment and ground water inaccurately; nonetheless, transport models applied to problems of environmental protection and ground water remediation almost invariably employ this technique. To examine the consequences of this practice, the authors consider transport in one dimension of Pb and other heavy metals through an aquifer containing hydrous ferric oxide, onto which many heavy metals sorb strongly. They compare the predictions of models calculated using the K{sub d} approach to those given by surface complexation theory, which is more realistic physically and chemically. The two modeling techniques give qualitatively differing results that lead to divergent cleanup strategies. The results for surface complexation theory show that water flushing is ineffective at displacing Pb from the sorbing surface. The effluent from such treatment contains a persistent ``tail'' of small but significant levels of contamination. Subsurface zones of Pb contamination, furthermore, do not migrate rapidly or far in flowing ground water. These results stand in sharp contrast to the predictions of models constructed using the K{sub d} approach, yet are consistent with experience in the laboratory and field.

Authors:
;
Publication Date:
Research Org.:
Dept. of Geology, Urbana, IL (US)
OSTI Identifier:
20080441
Alternate Identifier(s):
OSTI ID: 20080441
Resource Type:
Journal Article
Journal Name:
Ground Water
Additional Journal Information:
Journal Volume: 38; Journal Issue: 3; Other Information: PBD: May-Jun 2000; Journal ID: ISSN 0017-467X
Country of Publication:
United States
Language:
English
Subject:
54 ENVIRONMENTAL SCIENCES; GROUND WATER; REMEDIAL ACTION; LEAD; ENVIRONMENTAL TRANSPORT; MATHEMATICAL MODELS; AQUIFERS; FORECASTING

Citation Formats

Bethke, C.M., and Brady, P.V. How the K{sub d} approach undermines ground water cleanup. United States: N. p., 2000. Web. doi:10.1111/j.1745-6584.2000.tb00230.x.
Bethke, C.M., & Brady, P.V. How the K{sub d} approach undermines ground water cleanup. United States. doi:10.1111/j.1745-6584.2000.tb00230.x.
Bethke, C.M., and Brady, P.V. Thu . "How the K{sub d} approach undermines ground water cleanup". United States. doi:10.1111/j.1745-6584.2000.tb00230.x.
@article{osti_20080441,
title = {How the K{sub d} approach undermines ground water cleanup},
author = {Bethke, C.M. and Brady, P.V.},
abstractNote = {Environmental scientists have long appreciated that the distribution coefficient (the K{sub d} or constant K{sub d}) approach predicts the partitioning of heavy metals between sediment and ground water inaccurately; nonetheless, transport models applied to problems of environmental protection and ground water remediation almost invariably employ this technique. To examine the consequences of this practice, the authors consider transport in one dimension of Pb and other heavy metals through an aquifer containing hydrous ferric oxide, onto which many heavy metals sorb strongly. They compare the predictions of models calculated using the K{sub d} approach to those given by surface complexation theory, which is more realistic physically and chemically. The two modeling techniques give qualitatively differing results that lead to divergent cleanup strategies. The results for surface complexation theory show that water flushing is ineffective at displacing Pb from the sorbing surface. The effluent from such treatment contains a persistent ``tail'' of small but significant levels of contamination. Subsurface zones of Pb contamination, furthermore, do not migrate rapidly or far in flowing ground water. These results stand in sharp contrast to the predictions of models constructed using the K{sub d} approach, yet are consistent with experience in the laboratory and field.},
doi = {10.1111/j.1745-6584.2000.tb00230.x},
journal = {Ground Water},
issn = {0017-467X},
number = 3,
volume = 38,
place = {United States},
year = {2000},
month = {6}
}