Investigation of pore scale processes at biogeochemical interfaces using sensor micromodels and Raman microscopy

• Applicant: Professor Dr. Thomas Baumann
• Subject Area: Soil Sciences
• Term: from 2007 to 2015
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 40976435

Biogeochemical interfaces (BGI) in soil control the fate of organic chemicals and the functioning of soil as a filter to protect groundwater resources. To understand and quantify the processes at BGI, the concentration gradients of organic chemicals have to be measured and the spatial and temporal dynamics of the BGI themselves have to be monitored. Microfluidic systems with the pore structure of soils (micromodels), allow the visualize the spatial development of BGI in a flow through system under varying environmental conditions with single interface resolution. This project extends the micromodel technique with a chemically sensitive sensor layer and with Raman microscopy to measure the concentration of hexadecane and phenanthrene, possible degradation products and changes of the BGI with high spatial and temporal resolution (<2 μm, <1 s). The measurements are non-destructive and do not require tracers in the fluid flow. The time series data of the spatial features and concentration gradients at BGI is a keystone for quantification of the processes at BGI and provides a link between projects on the molecular level (AFM), pore scale visualizations (CLSM, μCT) and projects on the dm-scale.

• DFG Programme: Priority Programmes
• Subproject of: SPP 1315: Biogeochemical Interfaces in Soil
• Participating Person: Professor Dr. Reinhard Nießner