Research project "Assessment and prediction of natural attenuation processes by means of a processrelated analysis at the creosote-contaminated site at Wülknitz"
BMBF funding priority KORA: "Controlled natural retention and degradation of pollutants in the remediation of contaminated soils and groundwater"
Partners:
- Umweltbüro GmbH Vogtland (D)
- Imprägnierwerk Wülknitz GmbH (D)
Funding: BMBF
Duration: January 2003 - December 2006
Project description: (http://www.natural-attenuation.de/ in German)
At the Wülknitz site, organic pollutants that were used primarily in wood impregnation were introduced into the soil and groundwater over decades. These have consequently led to widespread contamination with hydrocarbons (PAHs, CHCs, phenols and monoaromatics) in the aquifer.
Similar cases of damage are known not only in Germany but worldwide. On the basis of the current state of knowledge regarding the behavior of the pollutants, an assessment of the hazard potential for groundwater is only possible to a very limited extent. Each individual site therefore requires extensive site investigation. The aim of this project was therefore to expand the knowledge in this area in such a way that the natural attenuation potential is also realistically included in the assessment of such sites. Thus, it may be possible to make statements on cost-effective containment and remediation measures.
In principle, the pollutants mentioned are biodegradable and show a more or less well-developed adsorption behavior. The intensity of biodegradation of these organic pollutants varies greatly in the aquifer depending on the composition of the substances and the specific local conditions. The processes of elimination and, above all, mineralization of the pollutants depend on a large number of factors that vary in intensity from site to site. These factors are as yet poorly understood and difficult to assess in terms of their effects.
The elucidation of the processes was made possible by the process-related analytics to be developed within the framework of the project. As a prerequisite, both the significance of the redox parameters and the microbial degradation potential as well as the kinetic data and the interactions between the pollutants, their metabolites and the surrounding environment in the aquifer had to be better understood.
The main focal points of the work are:
- Practical and realistic basic investigations in the laboratory,
- investigations in column apparatuses operated with contaminated groundwater at the site as well as
- the designation and operation of a measuring field in the aquifer.
The main focus is to characterize the naturally occurring processes of the self-purification potential with regard to a realistic risk assessment. The results obtained with the help of the project should lead to a remediation strategy that ensures that only site-specific appropriate and cost-effective measures have to be carried out.