Title:
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Keynote: Generic geochemical modelling approach to the environmental impact assessment of urban contaminated materials
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Author(s):
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Comans, R.N.J.; Dijkstra, J.J.; Zomeren, A. van; Groenenberg, B.-J.
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Published by:
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Publication date:
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ECN
Environment & Energy Engineering
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2-9-2015
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ECN report number:
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Document type:
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ECN-M--15-040
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Conference Paper
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Number of pages:
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Full text:
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3
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Download PDF
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Abstract:
Geochemical modelling is increasingly being used in the
characterization and environmental risk assessment of contaminated
materials that are produced and/or applied in urban areas. While
geochemical models are mostly developed and tested for specific
types of materials, their performance is strongly determined by the
specific modelling approach and methods to estimate the required
model parameters. This presentation will give an overview of the
development of a generic multi-reactive surface geochemical
model. The generic character refers to its development and
application to a wide range of materials, as well as to the (sorption)
parameters used. The approach is being developed to describe the
speciation and solid/liquid partitioning (leaching) of major and
trace elements in contaminated (waste) materials and soils, based
on the notion that the reactive organic and mineral surfaces in the
model play a generic and determining role in element speciation
and leaching from these materials.
The multi-surface model relies on individual adsorption models
for which generic binding parameters have been developed and
published for a wide range of elements. It includes reactions for
aqueous speciation and solubility of selected minerals, in
combination with sorption to organic matter (NICA-Donnan
model), Fe/Al-(hydr)oxides (Generalized Two-Layer Model) and
clay (Donnan model). Model parameters are obtained with standard
methods for the estimation of the potentially available/reactive
fraction of the elements of interest, and the available amount of the
above reactive surfaces. Examples will be presented of model
applications to different secondary (waste) materials that are being
used in construction, to urban atmosferic dust and contaminated
soils, including measurements and model predictions of the
solid/liquid partitioning and speciation of a wide range of elements.
Finally, an outlook will be given towards recent model
developments and applications in environmental risk assessment of
contaminated materials.
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