  A multicomponent multiphase reactive transport simulator has been developed
to facilitate the investigation of a large variety of phenomena in porous media
including component transport, diffusion, microbiological growth and decay,
cell attachment and detachment and phase exchange. The coupled problem is
solved using operator splitting. This approach allows a flexible adaptation of
the solution strategy to the concrete problem.
  Moreover, the individual submodels were optimised to be able to describe
behaviour of Escherichia coli (HB101 K12 pGLO) in the capillary fringe in the
presence or absence of dissolved organic carbon and oxygen under steady-state
and flow conditions. Steady-state and flow through experiments in a Hele-Shaw
cell, filled with quartz sand, were conducted to study eutrophic bacterial
growth and transport in both saturated and unsaturated porous media. As E. coli
cells can form the green fluorescent protein (GFP), the cell densities,
calculated by evaluation of measured fluorescence intensities (in situ
detection) were compared with the cell densities computed by numerical
simulation. The comparison showed the laboratory experiments can be well
described by our mathematical model.
