The scope of the project is to develop a general chemical model for the interaction of benchmark pollutants (both organic and inorganic) with soils, taking into account the ionic composition of the solution and the solution pH.
The structural and spatial heterogeneity of the sorbing bulk soil matrix will also be assessed and a conceptual model will be developed. The behaviour of two different types of contaminants will be investigated, namely two selected heavy metals (Cu, Cd) and polycyclic aromatic hydrocarbons (PAHs), which represent a range of hydrophobicities (anthracene, pyrene, benzopyrene, benzo(ghi)perylene). It is planned to center the studies around a site with sandy soil, heavily polluted with organic and inorganic contaminants. The experimental approach consists of a series of different experiments that aim at
a) elucidating sorption equilibria and kinetics with respect to spatial and chemical-structural heterogeneous soils in batch experiments,
b) quantifying transport in laboratory scale soil columns, and
c) adaptation of a soil simulator to relevant soil/pollutant systems.
On the basis of the experimental findings simulation tools are to be developed for multicomponent, multiphase transport in porous media. The macroscopic physico-chemical transport model in terms of a system of partial and ordinary differential equations has to include various chemical and physical processes, which until now have only been considered separately, but ignoring their interactions. It is likely that the binding mechanisms of the investigated pollutants to the soil matrix can only be described in a multicomponent, multiphase environment, i.e. taking into account pH, ionic strength, etc. Thus a multicomponent model has to be set up describing the fate of the investigated pollutant(s) also on other ubiquitous solutes contained in the soil solution. It is to be expected that at least some of the processes will be in chemical non-equilibrium so that their kinetics have to be modelled too.
Funding SchemeCSC - Cost-sharing contracts
6703 HB Wageningen