Predictive Modeling of Organic Pollutant Leaching and Transport Behavior at the Lysimeter and Field Scales

Soil and groundwater pollution has become a global issue since the advent of industrialization and mechanized agriculture. Some contaminants such as PAHs may persist in the subsurface for decades and centuries. In a bid to address these issues, protection of groundwater must be based on the quantification of potential threats to pollution at the subsurface which is often inaccessible. Risk assessment of groundwater pollution may however be strongly supported by applying process-based simulation models, which turn out to be particularly helpful with regard to long-term predictions, which cannot be undertaken by experiments. Such reliable predictions, however, can only be achieved if the used modeling tool is known to be applicable. The aim of this work was threefold. First, a source strength function was developed to describe the leaching behavior of point source organic contaminants and thereby acting as a time-dependent upper boundary condition for transport models. For general application of these functions dimensionless numbers known as Damköhler numbers were used to characterize the reaction of the pollutants with the solid matrix. Two functions were derived and have been incorporated into an Excel worksheet to act as a practical aid in the quantification of leaching behavior of organic contaminant in seepage water prognoses. Second, the process based model tool SMART, which is well validated for laboratory scale data, was applied to lysimeter scale data from two research centres, FZJ (Jülich) and GSF (München) for long term predictions. Results from pure forward model runs show a fairly good correlation with the measured data. Finally, the derived source term functions in combination with the SMART model were used to assess groundwater vulnerability beneath a typical landfill at Kwabenya in Ghana. The predicted breakthrough time after leaking from the landfill was more than 200 years considering the operational time of the facility (30 years). Considering contaminant degradation, the landfill would therefore not cause groundwater pollution under the simulated scenarios and the SMART model can be used to establish waste acceptance criteria for organic contaminants in the landfill at Kwabenya

Level thesis:degree_level

thesis.doctoral

Grantor dc:publisher

Technische Universität Dresden

Year

2007

Author dc:creator

• Amankwah, Edward Akwasi

Contributors dc:contributor

• Liedl, Rudolf
• Grathwohl, Peter
• Gräber, Peter-Wolfgang

• Model Prognoses
• Organic Pollutants
• Lysimeter
• Scale
• PAHs
• Reactive Transport
• Point Sources
• Modellprognosen
• Organische Schadstoffe
• Lymetermaßstab
• PAKs
• Punktquellen
• Reaktive Transporte