Working Packages (WPs)

WP 1: The soil/groundwater interface – a natural barrier under dynamic hydraulic conditions

The focus of this WP lies on the unsaturated/saturated water interface as well as the transition zone between surface water and groundwater. These zone are natural barriers for dissolved organic matter (DOM), nutrients and contaminants which keeps the groundwater free from these substances. However, common water table fluctuations as well as extreme events like floods and droughts impact the transport of substances within these zones. Work in WP 1 focusses on the identification and quantification of physical, chemical, and biological processes in the transition zones which control transport of substances. Of particular interest is the development of monitoring tools, i.e. stable isotope techniques, to follow the irregular dynamics in a high spatial and temporal resolution.

WP 2: Effects of hydrogeochemical dynamics on the natural attenuation of point sources

The transition between contaminant areas and the surrounding non-contaminated zones are “hot spots” of microbial degradation. The activity of bacteria within these zones is, however, strongly driven by the geochemical gradients, substrate supply, electron acceptor availability, and contaminant concentration. Main objective of WP 2 is to examine how sensitive microbial communities respond to dynamics in environmental conditions and how this affects their degradation efficiency. In various projects we examine the effect of groundwater fluctuations on sessile biodegrader populations. A current focus of research lies on the role of phages steering, and the composition and function of bacterial communities.

WP 3: Dynamic transformation and elimination pathways for diffuse and emerging contaminants

Diffuse contaminants like nitrate, pesticides, care products and pharmaceuticals and pathogens deriving from waste water as well as the application of manure, fertilizers and pesticides are of primary concern in aquifers. However our knowledge about their distribution, transformation and elimination pathways still remain fragmentary. The spreading of substances and the governing elimination pathways as controlled by microbial activity,  hydrodynamics, spatial heterogeneity and redox processes are therefore in the focus of this WP. In particular, the development of specific tools like biomarkers, bioindicators and bioassays is promoted in order to improve existing monitoring schemes.