Heavy metal distribution model under estuarine mixing

Citation
F. Mwanuzi et F. De Smedt, Heavy metal distribution model under estuarine mixing, HYDROL PROC, 13(5), 1999, pp. 789-804
Citations number
35
Categorie Soggetti
Environment/Ecology
Journal title
HYDROLOGICAL PROCESSES
ISSN journal
08856087 → ACNP
Volume
13
Issue
5
Year of publication
1999
Pages
789 - 804
Database
ISI
SICI code
0885-6087(19990415)13:5<789:HMDMUE>2.0.ZU;2-#
Abstract
In modelling the fate and transport of heavy metals, the sorption processes , through the distribution coefficient, are applied to determine the amount of sorbed and dissolved fractions. Usually, these distribution coefficient s are assumed to depend only on suspended sediment interactions. In estuari es, however, observations indicate that dissolved concentrations increase w ith salinity. It is hypothesized that salt competes for binding sites, lead ing to lower distribution coefficients. To study the fate and transport of heavy metals in an estuarine environment, a two-dimensional finite volume, depth-averaged toxic transport model has been developed. The distribution c oefficients are approximated as a function of sodium activity or salt conce ntration. Other model parameters are obtained from a recently developed hyd rodynamic model, salt transport and cohesive sediment transport modules. Th e model has been applied to the Scheldt Estuary and the results for both so rbed and dissolved heavy metal concentrations agree fairly well with measur ed data, indicating that under estuarine mixing, salt concentration is an i mportant factor affecting the fate and transport of heavy metals. Copyright (C) 1999 John Wiley & Sons, Ltd.