1. To experimentally investigate and to model the influence of humic substance interactions with different soil components on both the equilibrium and dynamic behaviour of heavy metal ions in model systems;
2. To test the validity of the developed models in soil systems.
The understanding of heavy metal ions behaviour and their transport in a complex soil system must rely on the detailed knowledge of their distribution between the liquid and the solid phase. Humic substances are potential carriers for heavy metal ions.
To realize the project objectives, experimental methods and modelling descriptions will be developed on simple model systems and will be further applied on soil samples.
The project will consist of a number of steps:
1. The coating of selected soil components (oxide, clay mineral, carbonate) with humic substances. The humic substances themselves can be labelled for their monitoring.
2. The influence of this humic substance coatings on the kinetic and the equilibrium behaviour of selected heavy metal ions (Cd, Zn) under well controlled conditions of pH and ionic strength in batch experiments.
3. The transport behaviour of heavy metal ions in columns with uncoated and humic substance coated soil components.
4. The investigation of more environmentally relevant conditions corresponding to the presence of competing metal ions (Ca, Fe, Al) and complex forming ligands (carbonate, chloride) in both batch and column experiments.
5. The development of a physico-chemical model that accounts for humic substance and heavy metal ion adsorption and its implementation into a simple porous medium transport model to simulate the column experiments.
6. To test the validity of the developed methodology and models by batch and column experiments on selected soil samples.
Funding SchemeCSC - Cost-sharing contracts
LE11 3TU Loughborough