Imaging and image simulation of organic target compound migration between different biogeochemical interfaces of a soil horizon using positron emission tomography and the lattice Boltzmann equation approach

Principle investigators: Prof. Dr. Michael Kersten, Dr. Johanna Lippmann-Pipke
Co-workers: Dr. Johannes Kulenkampff, Faisal Khan

We propose to use positron emission tomography (PET laboratory at FZD) for imaging of tracer migration in a soil horizon, to be coupled with image simulation using the lattice Boltzmann equation (LBE) modeling approach. PET enables direct visualization of inert KF or KBr solute migration at the soil horizon scale, but also reactive halogenated organic target (2,4-D and MCPA) compound migration down to nM concentrations once radiolabelling with 18F or 76Br marker is achieved. Retardation at biogeochemical interfaces with different sorption properties could then be imaged in-situ. Theoretical image simulation for process verification will be enabled by introducing a multi-grid approach and additional kinetic boundary conditions in the parallelized LBE solver GEODICT. As a boundary condition for the latter, the real pore scale and distribution of biogeochemical interfaces will be derived by X-ray micro-tomography (┬ÁCT laboratory) down to 300 nm spatial voxel resolution. The aim is to produce by both approaches velocity field movies due to heterogeneous biogeochemical retardation of the target compounds with high resolution in both the spatial and temporal scale (4D).