Molecular mechanisms in bio-geo-interactions: From a case study to general mechanisms

The understanding of molecular mechanisms in the cycling of elements in general is essential to our alteration of current processes. One field where such geochemical element cycles are of major importance is the prevention and treatment of acid mine drainage waters (AMD) which are prone to occur in every anthropogenic, modified landscape where sulfidic rock material has been brought to the surface during mine operations. Microbiologically controlled production of AMD leads not only to acidification, but at the same time the dissolution of heavy metals makes them bioavailable posing a potential ecotoxicological risk. The water path then can contaminate surface and ground water resources which leads to even bigger problems in large catchment areas. The investigation of mechanisms in natural attenuation has already provided first ideas for applications of naturally occurring bioremediation schemes. Especially an improved soil microflora can enhance the natural attenuation when adapted microbes are applied to contaminated areas. Future schemes for plant extraction, control of water efflux by increasing evapotranspiration, and by subsequent land use with agricultural plants with biostabilization and phytosequestration potential will provide putative control measures. The mechanisms in parts of these processes have been evaluated and the resulting synthesis applied to derive a bioremediation plan using the former uranium mine in Eastern Thuringia as a case study.