|Leachate prognosis via lab experiments about scalability, investigation of its relevance in practise; Sub-project I: Investigation of the source strength and factors used in up-scaling leachate prognoses|
|Project manager:||PD Dr.-Ing. Baldur Barczewski, Dr.-Ing. Norbert Klaas, M.Sc.|
|Research assistants:||Dr.-Ing. Sylvia Mackenberg|
|Duration:||15.8.2002 - 30.6.2005|
|Funding:||Bundesministerium für Bildung und Forschung (BMBF)|
This project is part of the research area:
Behaviour of Contaminants in the Subsurface
Abstract:The BBodSchV establishes a method of estimating either the contaminated materials or the expected pollution amounts in the ground water via the leachate prognosis. The research differentiates between the terminology of source strength and pollutant transport. Objective of the research project was to investigate the leaching of the source strength at various scales. The goal was not only to evaluate both traditional and new leaching procedures, but also to focus on potential correlations between laboratory and field work especially with respect to up-scaling from lab results to the actual sites.
Batch experiments produce a yes/no result as criterion for further investigations of the materials. Additionally, they inform one about possible systematic links between leach concentrations and l/s ratios. For some parameters a direct scalability was proven - from the lab results to the field setting. With the newly developed infinite-sink-method it is possible to directly compare and categorise PAH contaminated materials based on their contamination release attributes. Further, an estimation about the timebased development, i.e. release of the PAH source strength, is possible. One can assess the long-term contamination threat from pollut-ants mobilised by water.
Saturated column experiments showed potential correlations between the leach concentration and the l/s ratios. In order to be able to quantify the impact of the contact time, at least two column experiments with varying contact times are necessary. Where applicable, one may be able to determine this impact via interruptions in the seepage periods. The first-flush-effect has proven to be problematic. However, the undesired effect is minimised in set-ups with a bigger column diameter. A good reference value for a realistic start concentration can be taken from the MBSE.
The comparison of results from the lysimeter experiments, i.e. unsaturated column experiments, with the saturated batch and saturated column experiments, showed, that one can directly translate some of the parameters from the laboratory to the field.